THE ' &’• * ** 
ANATOMY AND PHYSIOLOGY 
fi 
whe iB©iDWa 1 
CONTAINING 
THE ANATOMY 
OF THE BONES, MUSCLES, AND JOINTS; AND THE HEART AND 
ARTERIES : 
BY JOHN BELL; 
AND 
THE ANATOMY AND PHYSIOLOGY 
OF THE BRAIN AND NERVES, THE ORGANS OF THE SENSES* 
AND THE VISCERA: 
BY CHARLES BELL, F. R. S. E. 
SURGEON TO THE MIDDLESEX HOSPITAL, AND READER OF ANATOMY 
IN THE CHAIR OF DR. HUNTER, &C. ScC. 
FOURTH AMERICAN, FROM THE FOURTH ENGLISH EDITION*. 
IN THREE VOLUMES. 
VOL. I. _ MlckftFinL 
.YEW tORR: 
PUBLISHED BY COLLINS £jf CO. NO. 189, PEARL STREET. 
1822. TO 
ALEXANDER WOOD. 
SURGEON; 
WHOSE ABILITIES AND SKILL, AND DISINTERESTED CONDUCT, 
HAVE RAISED HI VI, BY COMMON 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, 
JiY HIS PUPIL, 
JOHN bell; THE 
ANATOMY 
OF THE 
HUMAN BODY- 
VOL L 
CONTAINING 
THE ANATOMY 
os 
THE BONES, MUSCLES, AND JOINTS, THE 
HEART AND CIRCULATION, 
SJS'V 
THE LUNGS. PREFACE. 
To those, who are at all acquainted with books on ana- 
tomy, the appearance of a new one on the subject will 
not be surprising. To those, who are not yet acquainted 
with such writings, I have only to say that I have writ- 
ten this book, because I believed that such a one was 
needed, and must be useful. I have endeavoured to 
make it so plain and simple as to be easily understood; 
I have avoided the tedious 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, compared with the studied harshness, and I 
may say, obscurity of anatomical description. If an au- 
thor may ever be allowed to compare his book with 
others it must be in the mechanical part; and I may 
venture to say, that this book is full and correct in the 
anatomy, free and general in the explanations, not re- 
dundant, 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 will naturally feel how use- 
ful 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 ac- PREFACE. 
knowledge, that 1 introduce such theories only, as should 
connect the whole, and may be fairly distinguished as 
the physiology of acts : and he will perceive, that in this 
too, I feel a deference for the public opinion, and a res- 
pect 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 concerning 
his own book, than to omit those apologies which cus- 
tom requires, which give assurance, that he has not en- 
tered upon his task rashlv, nor performed it without 
some labour and thought, and which are the truest signs 
of his resnect for the public, and of his care for that 
science to which he has devoted his life. 
With these intentions and hopes, I offer this book to 
the public ; and more particularly to those in whose edu- 
cation I have a chief concern ; not without a degree of 
satisfaction at having accomplished what I think cannot 
fail to be useful, and surely not without an apprehen- 
sion of not having done (in this wdde and difficult sub*- 
ject) 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 connexion, a book 
of science is insulated and lost. This relation and sub- 
serviency of his own particular task to some greater whole, 
is first in an author’s mind : he ventures to look forward 
to its connexion 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 enter- 
ing 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 per- 
fect plan ; and there are very few with whom a con- 
sciousness of tins does not make a deep and serious im- 
pression at some future period, accompanied with severe PREFACE. 
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 to- 
wards that period in which we are to enter upon a most 
difficult profession, 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, unprofitable 
labour :—for there is no study which a young man enters 
upon with a more eager curiosity ; but not instructed 
in wffiat is really useful, nor seriously impressed with 
the importance of his future profession, he thinks of his 
studies rather as the amusement, than as the business, 
of life ; slumbers through his more laborious and useful 
tasks, and soon falls off to the vain pursuit of theories 
and doctrines. 
If I were not persuaded of the important consequences, 
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 limit- 
ed fortune, or the will of his friends, by absence from 
his native country, or by the destination of his future life, 
is restricted to a few years of irregular, capricious, ill de- 
re cted 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 
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 com- PREFACE. 
pleted, ere he have learnt that most useful of all lessons 
—the true plan of study ; his opportunities come to be 
valued (like every other happiness) only when 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 privilege of such stu- 
dies by honest labour, and a faithful pursuit of real and 
useful knowledge. Of this knowledge, anatomy surely 
forms the greatest share.—Anatomy, even while it is 
neglected, is universally acknowledged to be the very 
basis of all medical skill.—It is by anatomy that the 
physician guesses at the seat, or causes, or consequences, 
of any internal 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 student. 
He begins with a strong conviction that this is the 
great study, and with an ardent desire to master 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, con- 
scious of his ignorance in that branch which is to be 
received as the chief test of his professional skill; or 
when, perhaps, he feels a more serious and manly im- 
pression, the difficulty and importance of that art which 
he is called to practice. 
Yet, in spite of feeling and reason, the student en- 
courages in himself a taste for speculations and theories, 
the idle amusements of the day, which even in his own 
short course of study, he may observe sinking in quick PREFACE. 
succession into neglect and oblivion, never to revive; 
he aspires to the character of a physiologist, to which 
want of experience and a youthful fancy, have assigned 
a rank and importance which it does not hold in the esti- 
mation of those who should best know its weakness or 
strength. The rawest student, proud of his physiolo- 
gical knowledge, boasts of a science and a name which 
is modestly disclaimed by the first anatomists, and the 
truest physiologist of this or any age : Dr. Hunter speaks 
thus of his physiology, and of his anatomical demonstra- 
tions : “ Physiology, as far 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, 
“ provided the student is acquainted with philosophy and 
“ chemistry, and is an expert and ready anatomist; 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 upon 
“ the subject, there is almost as little inducement to 
“ attend lectures upon physiology, as there would be for 
“ gentlemen to attend lectures upon government, or 
<e 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 improvements either in matter or in 
“ arrangement. 
“ In our branch, those teachers who take but little 
“ pains to demonstrate the parts of the body with pre- 
“ cision and clearness, but study to captivate young minds 
“ with ingenious speculation, will not leave a reputation 
“ that will outlive them half a century. 
“ I always have studied, and shall continue my endea- 
“ vours, to employ the time that is given up to anatomi- 
“ cal 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, 
u all subtilty : to make a show, and to appear learned and PREFACE. 
“ ingenious in natural knowledge, may flatter vanity ; to 
“ know facts, to'separate them from suppositions, to range 
“ and connect them, to make them plain to ordinary 
“ capacities, and above all, to point out the useful appli- 
“ cations, 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. 
In 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 freely. And I may recommend it to those 
who superintend the education of students, to consider 
whether they have not in it a work calculated to open 
the minds of the pupils to the right understanding of the 
important subjects of their studies, and to give them cor- 
rect and liberal views of their profession. It will not be 
soon surpassed in correctness and minuteness of descrip- 
tion. 
I have not dared to touch the History of the Arteries ; 
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 compression of the great arteries, 
is an error on the safe side. I may add, that without the 
necessity of making 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 amputating at the shoul- 
der-joint. I think, in one instance, the patient died from PREFACE. 
the loss of blood. Few assistants have strength and dex- 
terity to accomplish the entire compression of the artery 
in this operation, and such have been my fears of hae- 
morrhage, 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 themselves 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 Ana- 
tomy and Physiology of the Viscera. 
CHARLES BELL. 
S0H0-SqUARE, LONDON, 
Jan. 1816. OF 
THE FIRST VOLUME. 
ANATOMY 
OF THE 
BONES, MUSCLES, AND JOINTS. 
BOOK I. 
OF THE BONES. 
CHAP. I. 
OB THE FORMATION AND GROWTH OF BONES, 1. 
Page 
History of the Doctrines of Ossification, - 2 
Phenomena of ossification, ----- 4, 
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 Ossifications 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 Cancelli. 
5. The Marrow. 
6. The Lamellae, or Bony Plates. 
7. The Holes of Bones, - - - - „ 17 
8. The Vessels, - - - - ~ - !g 
9. The Periosteum. Page 
10. The Cartilages, 20 
The Callus and Regeneration of Broken 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. III. 
DESCRIPTION OF THE INDIVIDUAL BONES OF 
THE SKULL, 35. 
Os Frontis, ------- 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. Cruci d Spine. 
3. Posterior Tuberosity, 
ii. Internal Surface. 
1. Great 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. CONTENTS. 
Page 
Petrous Part, » - - - 44 
Pi •ocesses. 
1. Zygomatic. 
2. Styloid. 
3. Vaginal. 
4. Mastoid or Mamillary, 
5. Auditory. 
Holes. 
For the Ear. 
1. Meatus Auditorius Externus. 
2. Internets. 
3. Small Hole Receiving a Branch 
from the fifth Pair of Nerves. 
4. Stylo-Mastoicl 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 (Ethmoides, 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. Alas. 
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. 
■ oi., r. CONTENTS. 
Pajje 
2. Foramen Lacerum 56 
3. Rotundum. 
4. Ovale. 
5. Spinale. 
6. Pterygoid, or Yidian Hole. 
CHAP. IV. 
BONES OF THE FACE AND JAWS, 58. 
Ossa Nasi, - -- -- --58 
Ossa maxjllaria Superiora, 59 
Processes. 
\. Nasal. 
2. Orbitary. 
3. Malar. 
4. Alveolar. 
5. Palate Process. 
Antrum, Maxillare, or Higmoranium. 
Holes. 
1. Infra Orbitary. 
2. Foramen Incisivum, or Anterior Pa- 
latine Hole. 
3. Posterior Palatine Hole. 
Ossa Palati, 64 
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 inferiora, - 65 
Vomer, 66 
Os Mali, 6T 
Processes. 
1. Upper Orbitary. 
2. Inferior Orbitary. 
3. Maxillary. 
4. Zygomatic. 
5. Internal Orbitary. 
Os Maxill/E Inferioris. - - - - - 6T 
Processes. 
1. Coronoid. 
2. Condyloid. 
3. Alveolar. CONTENTS. 
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 of the Vertebrse, 70 
General Description of a Vertebra, - - 71 
1. Body of the Vertebra. 
2. Articulating, or Oblique Processes. 
3. Spinous Processes. 
4. Transverse Processes. 
Vertebrae of the Loins, - - - 73 
Vertebrae of the Back, 74 
Vertebrae of the Neck, . ... 75 
Atlas, - - - - - - - 76 
Dentatus, ------ 7 8 
Medullary Tube and the Passage of the Nerves, 79 
Intervertebral Substance, - - - 79 
Motions of the Vertebrse, 80 
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 
— 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 Cartila- 
ges 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— CON TEN To. 
I'age 
2. Dorsum—3. Costa—4. Linea 
Innominata, SO 
ii. Os ischium, or Hip-Bone 
1. Body—2. Tuber—3. lla- 
mus, - - - - 91 
iii. Os Pubis, or Share-Bone 
Body Crest——Ramus, 92 
Recapitulation of the chief Points of the 
Anatomy of the Pelvis, 93 
Size of the Pelvis in Man and Woman, 94 
Remarks on the Separation of the Bones 
of the Pubes during Labour. - 95 
CHAP. VI. 
BONES OF THE THIGH, LEG, AND FOOT, 98. 
1. Femur, 98 
1. Body. 
2. Head. 
3. Neck. 
4. Trochanter major. 
5. Trochanter minor. 
6. Linea aspera. 
7. Condyles. 
IT. Tibia, 102 
1. Upper Head, 
2. Body. 
3. Lower Head—Inner Ankle. 
III. Fibula, 104 
1. Upper Head. 
2. Lower Head—Outer Ankle. 
IV. Rotula, Patella, or Knee-pan, - - 105 
V. Tarsus, or Instep, ----- 106 
1. Astragalus. 
2. Os Calcis. 
3. Os Naviculare. 
4- 1 
5. > Cuneiform Bones. 
6. J 
7. Os Cuboides. 
\I. Toes,—Sesamoid Bones - 109 
VII. Metatarsus and its five Bones, - - 110 CONTENTS. 
CHAP. YII. 
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. - - 11J 
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 Coro- 
noid Process of the Ulna. 
III. Ulna and Radius, 118 
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, 120 
1, Body. CON TEN TS. 
Fagre 
2. Upper Head, - 120 
3. Neck. 
4. Point 'or the implantation of the Biceps. 
Fit xor Cuoiti. 
6. Lower Head. 
IV. Hand and Fingers, ----- 121 
General Explanation o' *he Hand and Wrist, 
Carpus, Matacarpus, an.; Fingers. 
1. Carpus or Wrist, - 122 
1. Row forming the Wrist, - 123 
2. Os Lunare, 
3. Os Cuneiforme. 
4. Os Pisifor ne. 
2. Row supporting the Metacarpal 
Bone's, - - - - 124 
1. Trapezium. 
2. Trapezoides. 
3. Os Magnum. 
4. Os Unciforme. 
II. Metacarpus, - 125 
III. 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. T e 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 Vascularit and Constitution of the bony Part 
of the Tooth, - - - - - - 134 
Of the Formation and G owth of the Teeth, - 138 
Of the Grow h of t e second Set of Teeth, and the 
shedding of the first, - - - 141 CON TENTS. 
BOOK II. 
OF THE MUSCLES. 
CH AP. I. 
MUSCLES OF THE FACE, EYE, AND EAR. 
Page 
I. Muscles of the Face, ----- 145 
1. Occipito Frontalis. 
2. Corrugator Supercilii, - 146 
3. Orbicularis Oculi, or Palpebrarum, - 147 
4. Levator Palpebrae Superioris. 
II. Metscles of the Nose and Mouth, - - 148 
5. Levator Labii Superioris, et Alse Nasi. 
6. proprius. 
7. Levator Anguli Oris, or, Levator Com- 
munis Labiorum, - 149 
8. Zygomaticus major. 
9. minor. 
10. Buccinator, 
11. Depressor Anguli Oris, - 150 
12. Depressor Labii Inferioris, or Quadratus 
Genae. 
13. Orbicularis Oris, - - - - 151 
14. Depressor Labii Superioris, et Alse Nasi, 152 
15. Constrictor Nasi. 
16. Levator Menti. 
III. Muscles of the External Ear. - - 152 
17. Superior Auris, - - - 153 
18. Anterior Auris. 
19. Posterior xAuris. 
20. Helicis major, 
21. Heiicis minor, - - - . - 154 
22. Tragicus. 
23. Antitragicus. 
24. Transversus Auris. 
IV. Muscles of the Eye-ball. - 154 
General Explanation of these Muscles. 
25. Rectus Superior, 
26. Rectus Inferior. 
27. Rectus Internus. 
28. Rectus Externus. 
29. Obliquus Superior, - - - 156 
30. Obliquus Inferior. CONTENTS. 
MUSCLES Of THE LOWER JAW, THROAT, AND TONGUE. 
Page 
I. Muscles on the Lower Jaw, ... 157 
31. Temporalis. 
32. Masseter. 
33. Jnternus, 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. Scutlform, or Thyroid Cartilage, - 160 
2. Cricoid Cartilage. 
3. Arytenoid Cartilages, and Rima 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-hvoideus. 
35. Sterno-thyroideus. 
36. Omo hyoideus. 
Action of these muscles. 
2. Muscles which move the Throat upwards. 
37. Mylo-hyoideus. 
38. Genio-hyoideus, - - - - 163 
39. Stylo-hyoideus. 
40. Digastricus, or Biventer Maxillae Inferio- 
ris. 
3. Muscles moving the Parts and Cartilages of 
the Larynx upon each other, - - 164 
41. Ilyo-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 Palate and Pharynx. 
48. Azygos Uvulae. - - - - - 166 
CHAP. IL CONTENTS. 
Page 
49. Levator Palati Mollis. - - 166 
50. Circumflexus Palati, or Tensor Palati 
Mollis. 
51. Constrictor Isthmi Fauscium, - - 167 
52. Palato Pharyngeus. 
Pharynx explained. 
53. Stylo-pharyngeus, - - - - 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 MUSCLES OE 
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, - - - » 174 
68. Subclavius. 
Motions of the Scapula. 
II. Muscles moving the Os Humeri, or Arm-Bone. 
69. Pectoralis Major, - - - 175 
70 Latissimus Dorsi. 
71. Deltoides, ------ 176 
72. Coraco brachialis - - - - 177 
73. Supra Spinatus. - - - - 178 
VOL. i. d CONTENTS. 
Page 
74. Infra Spinatus, - - - - - 178 
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, - - - - 180 
III. Muscles moving the Fore-arm. 
i. Muscles bending the Fore-arm, - - - 181 
78. Biceps Brachii Flexor. 
79. Brachialis Internus, - - - - 182 
ii. Muscles e tending the Fore-arm. 
80. Triceps Extensor. 
81. Aconeus, - - - - - - I84 
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 
Pronation and Supination, Flexion and Ex- 
tension, explained, - - - 185 
5. Flexors, arising from the Inner Condyle, 186 
82. Pronator Teres Iladii. 
83. Palmaris Longus, - - - 187 
84. Palmaris Brevis, or Cutaneous, - - 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 Iladii Longus. 
93. Extensor Carpi liadialis 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, "1 - 197 
99. Extensor Secundus Pollicis, L - - 198 
100. Extensor Tertius Pollicis. J 
101. Indicator, - . - - - -199 
102. Supinator Brevis. CONTENTS. 
Page 
V. Muscles seated on the Hand. - 199 
Table of these Muscles, - 200 
103. Abductor Pollicis. n 
104. Opponens Pollicis. I . 
105. Flexor Brevis Pollicis. /" 
106. Abductor Pollicis. J - 202 
107. Abductor Minimi Digiti 1 
108. Flexor Parvus Minimi Digiti, l - 203 
109. Adductor Minimi Digiti, J 
110. Abductor Indicis. 
111. Interossei Interni. 
112. Interossei Externi. 
CHAP. IV. 
MUSCLES OF RESPIRATION, OR OF THE RIBS. 204 
General Explanation and Table of these Muscles. 
113. Serratus Superior Posticus. - - 205 
114. Serratus Inferior Posticus. 
115. Levatores Costarum, - 206 
116. Intercostales. 
117. Triangularis Sterni, or, Sterno costalis 207 
CHAP. V. 
MUSCLES OF THE HEAD, NECK, AND TRUNK. 208 
I. Muscles of the Head and Neck. 
118. Splenius. 
119. Complexus. 
120. Trachelo mastoideus. - - 21G 
121. Rectus Minor. 
122. Rectus Major. 
123. Obliquus Superior, - 211 
124 Obliquus Inferior. 
II. Muscles of the Trunk. 
125 Quadratus Lumborum. 
,126 Longissimus Dorsi, - 212 
127- Sacro Lumbalis, - - " - 213 
128. Cervicalis Descendens. 
129. Transversalis Colli, - - - 214 
Arrangement of the intricate Set of 
Muscles filling up the Hollows and 
Interstices among the Spines and 
Processes of the Vertebree, - 214 CONTENTS, 
Page 
ISO Spinalis Cervicis, - - - 215 
131. Spinalis Dorsi 
132. Semi-Spinalis Dorsi, - - 216 
133. Multifidus Spinse 
134. Inter-spinalis Colli, Dorsi, et Lumborum, 217” 
135. Inter-transversales. 
III. Muscles on the fore part of the Head and 
Neck, completing the Catalogue of those belong- 
ing to the Spine. 
136. Platysma Myoides. 
137. Mastoideus, - 218 
138 Rectus Internus Capitis Major. 
139. Rectus Internus Capitis Minor. 
140 Rectus Capitis Lateralis. 
141. Longus Colli. 
142. Scaleni, ------ 219 
CHAP. YI. 
OF THE MUSCLES OF THE ABDOMEN, AND OF 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, &c. 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 Her- 
nia, and the Points at which the Bowels 
are protruded - - - - - 227 
Uses of the Abdominal Muscles. CONTENTS. 
Page 
II. Diaphragm, . - - - - - 227 
149. The Diaphragm. 
1. The Greater, or Upper Muscle of the 
Diaphragm, - ,228 
2. 'The Lesser Muscle of the Diphragm. 
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 Perinsei, - - 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 
Femoris, - - - - - 238 
157. Psoas Magnus. 
158. Psoas Parvus.- 
159. Jliacus Internus, - 239 
160. Pectineus, or Pectinalis. CONTENTS. 
. Page 
161. Triceps Femoris, - - - 240 
1. Adductor Longus. 
2. Adductor Brevis. 
3. Adductor Magnus, ... 241 
162. Obturator Externus. 
163. Gluiaeus Maximus, - 242 
16-t. Glmaeus Medius, or Minor. 
, 165. Glutaeus Minimus, .... 243 
167* 
168. Pyriformis. 
169. Obturator Internus, - 244 
170. Quadratus Femoris. 
Motions of the Thigh, and Action of these Muscles. 
II. 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. Semitendinosus, >> 250 
178. Semimembranosus. 
179. Pophtaeus, - 251 
180. Biceps Cruris. 
III. Muscles of the Foot, - 252 
Arrangement, 
i. Extensors. 
181. Gastrocnemius. 
182. Soleus, ------ 253 
183. Plantaris. 
184. Peronaeus 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, 
. . Page 
189. Flexor Longus Polllcis. - - 257 
190. Flexor Longus Digitorum Pedis Perforans, 258 
191. Massa Carnea J- Silvii, or, Plants Pedis, 259 
192. Flexor Brevis Digitorum. 
193. Lumbricales, ----- 260 
194. Extensor Longus Digitorum Pedis. 
.195. Extensor Digitorum Brevis, - - 261 
196. Extensor Pollicis Propriiis. 
Crucial Ligament, - 262 
197. Abductor Pollicis. 
198. Flexor Brevis Pollicis, S 263 
199. Adductor Pollicis. J 
200. Transversalis Pedis. 
201. Abductor Minimi Digiti. 
202. Flexor Brevis Minimi Digiti, - - 264 
203. Interossei Interni. 
204. Interossei Externi. 
205. Plautaris Aponeurosis. 
CHAP. IX. 
OF THE MUSCULAR POWER, 26£ 
CHAP. X. 
OF THE TENDONS, LIGAMENTS, BURSAE, 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. Bursae Mucosae. 
3. Vaginae, 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 Connexions of these 
Parts, - - - 282 
Constitution and Nature of those less feeling Parts 
—almost insensible in Health,—slow to inflame— 
their Inflammation very violent though slow—Dis- 
eases to which they are liable, Contents. 
BOOK III. 
OF THE JOINTS. 
CHAP. I 
Page 
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. Fiat membranous Ligament from the Ring 
of the Atlas to the Ring of the Occipital 
Hole 287 
. 3. Articulation of the Atlas with the Den- 
tatus. 
Capsules betwixt the Condyles of the 
V ertebrae. 
Transverse Ligament embracing the Neck 
of the Tooth-like Process—Capsular 
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, ----- 281 
Internal Ligaments, - - - 289 
Ligamenta Subflava Crurum Processum 
Spinosorum—Membranae 1 nterspinales— 
Ligamenta Processum 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 Capitella Costarum, 
Ligamentum Transversarium Externum. 
Internum. 
Capsule and Ligaments belonging to the 
Cartilages. CONTENTS. 
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 Shoulder. - 293 
III. joint of the Elbow, ----- 295 
The General Capsule of the whole Joint. 
The Lateral Ligaments, External and Inter- 
nal, ------ 296 
The Coronary Ligament of the Ulna. 
Acessory Ligaments. 
IV. Wrist, - - - _ - - - - 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 CONTENTS. 
Page 
Semilunar, or moveable Cartilages. - - 305 
Ligamentum Mucosum—and Ligametum Alare 
Majus et Minus, - - - 306 
Bursae Mucosae oi the Knee Joint. 
Jiecapitulation, explaining the Constitution of 
this Joint, and Uses of its several Parts, - 307 
III. Articulation of the Fibula with the Tibia, 308 
IV. Ankle Jo nt, ------ 309 
Ligamentum Superius Anticuni. 
Posticum. 
Inferius Posticum. 
Capsule. 
Ligamentum Deltoides, - - - - 310 
Fibulae Anterius. 
Perpendiculare. 
Inter Fibulam et Astragalum 
Poster ius. 
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. 
Bursae Mucosae of the Ankle and Foot, - 312 
Conclusion and Enumeration of the Joints. 
THE 
ANATOMY 
or THE 
HEART AND ARTERIES. 
BOOK I. 
OF THE HEART. 
CHAP. 1. 
GF THE MECHANISM OF THE HEART, 3i& 
General View of the Circulating System, - - 316 
O? THE P RTS OF THE HEART. 
Tense Cavae, - - - - » - 321 CONTENTS, 
Pape 
Right Sinus of the Heart, - 322 
Tuberculum Loweri. 
Auricle, ------ 323 
Auricular Valves. 
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. If. 
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, ------ 361 
Qualities of the Blood, ----- 367 
Ol the lied Globules, ------ 368 
Coagulable lymph, ----- 371 
Serum, - - - - - " 372 
General View of the Nature of the Bio d. 
Chemistry of the Blood, - - - - - 373 
Influence of Air upon the Blood - - - - 377 
1. In reddening the Blood, - 381 
2. In communicating its stimulant Powers, - 382 
3. In communicating Heat to the Body, - 383 
Of the respiration of animals, - 384 
Of the Membranes of Cavities, and particularly of the 
Membranes of the Thorax, - - - - 386 
Of the Pleura, ------- 389 
Of the Mediastinum, ------ 391 
Of the Pericardium, - - - - - - 394 
Of the Thymus Gland, ----- 395 
Of the Lungs. 
Trachea and Bronchi, - - - - - 396 
Bronchial Cells, 398 
Course of the Blood jn the Lungs, - 399 Fig.lt 
Plate I, 
Fig. 3. 
Fig.2. Plate JDL 
Fig.2. 
jFiffo3. 
Fig. 1. Mate UDL - 
Wig.2. 
Wig.l. 
Wig. 3. 
JFig.4- 
Wig.5. 
Wig, 7, 
Wig. 6. 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 central nucleus of bone forming in the cartilage. 
ee. Vessels penetrating from perichondrium into the cartilage: 
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. 
T). The patella, as yet a cartilage. 
e. The Upper extremity of the tibia, yet a cartilage. 
f. The bone forming in the cartilage. EXPLANATION OF THE PLATES. 
Fig. 3. 
Represents a section of the apophysis of a young bone ; the 
bony nucleus separated from the cartilage by maceration. 
-A. The cartilage. 
£. The bone. 
Explanation of 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. 
jB. 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.s 
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. 
bb. The old bone seen through the interstices of the new 
bone. 
ec. The new bone enclosing 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 wrong, 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 tl>ese injuries are sus~ EXPLANATION OF THE PLATES. 
tained, the old bone comes away as in this example; and the 
stump may yet do well. 
Explanation of Plate III. 
This plate illustrates the chapter on the formation of the 
teeth. 
Fig. 1. 
A tooth cut through and burnt. 
A. The enamel not affected by the heat. 
B. The body of the bone black. 
c. The canal 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. 
Cv The shell of this bony part of the tooth which was formed 
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. 
bb. Bone formed in circles round the tooth, 
c. The common matter of the tooth. 
B. 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 sacculus. 
s. The lower part of the pulp, when it can be seen without 
opening the sac* EXPLANATION OF THE PLATES* 
e. 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. rl he incisores of the first set of teeth. 
B. c. b. e. The rudiments of the eye-tooth. 
B. The pulp, having a connexion with the sacculus, and re- 
ceiving arteries from the bone. 
C. The soft pulp within the sac, and in situ• 
jd. The connexion 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 
A N A T O M Y 
OF THE 
BONES, MUSCLES, AND JOINTS. 
BOOK I. 
OE TIIE BOXES. 
CHAP. I. 
or 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 Tioble 
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 the Gallery. C. B, 2 
OF THE FORMATION 
memorials of the dead; the evidence of a former race of men 
exceeding ours in strength and stature; the only remains of 
creatures which no longer exist; the proofs of such changes 
on our globe, as we 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 through 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 no place 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. 
3 
sential point from this first notion. De Hide, a surgeon of 
Amsterdam, believed that bone or callus was not formed 
from a coagulable 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 re- 
paired 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 which 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 lamellae, 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 which surrounds and is attached to the 
surface of the bone, and which conveys the blood vessels to it. 4 
OF TI1E FORMATION 
periosteum being already converted into earth, and deposited, 
upon the surface 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 filled 
up with a sort of tompion, proceeding from the periosteum, 
which was thickened allround 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 to 
the 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 proof, and he again found quite the reverse of 
all this : That the callus, or the original bone, were 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, adhering chiefly to the heads or processes, 
while it hardly touched the body of the bone. He also found 
that the bone grew, became vascular, had 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 nuclsei, 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, gradually 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- 
ed 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 OP 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 to 
pain,* and as regularly changed as the softest 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 laved, 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 w'hole 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 cartilage, 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, which is formed also where it 
should not be, in the tendons, and in the joints, in the great 
arteries, and in their valves, in the flesh of the heart itself, or 
even in the soft and pulpy substance of the brain.j: 
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 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 follows, 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 be- 
gins, stretching its rays according to the length of the bone, 
* The obscurity on this subject is from the neglect of Penned terms. We 
shall presently see that the sensibility possessed by the bones, and the kind 
of pain to which 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 
bone. C. B. 
X The structure of the true and natural bone is different from the preter 
natural bony concretion in the vessels and membranes. C. B. 6 
OF THE FORMATION 
and then the cartilage begins to grow opaque, yellow, brittle ; 
it 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 
foretold by the spreading of the artery, and by the arrival of 
red blod. Every point of ossification has its little arteries, 
and each ossifying nucleus has so little dependence on the 
cartilage 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 ossifi- 
cation drops spontaneously from the cartilage, leaving the car- 
tilage 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 gene- 
ral 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 
radiated 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 vascular the bone of a chicken is 
before the ossification have fairly begun; how the ossification being begun, 
overtakes the arteries, and hides them, changing the 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 connection and commerce of ves- 
sels betwixt the periosteum and the bone; how by tearing up the outer layers 
of the tender bone, the vascularity of the inner layers is again exposed; and 
the most beautiful proof of all is that of our common preparations, where, by 
filling with injection the arteries of an adult bone, by its nutritious vessels, 
and then corroding the bone with mineral acids, we dissolve the earth, leaving 
nothing but the transparent jelly, which restores it to its original cartilagi- 
nous state ; and then the vessels appear in such 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 deposition 
of the bony part. AND GROWTH OF BONES. 
7 
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, 
joined 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 bones 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.* 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 hu- 
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; 
others again to perform certain offices within the body, as 
* The arteries of a bone branch with freedom, and with the same seeming 
irregularity as in other parts of the body The arteries do not exude their se- 
cretion from their sides, so as ro pile up the ridge of bone in their course 
The spcretion seems to be performed in their very extremities. C. B. 8 
OF THE FORMATION 
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 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 organi- 
zed mass of cartilage keep it in growth, extend, and yet pre- 
serve its form, and gradually enlarging in their own diameter, 
at last receive the entire blood.* Then the deposition of ear- 
thy 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 vessels ; and while they convey away 
the superfluous 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 consist- 
ence. 
If such organization of arteries to deposite bone, and ab- 
sorbents to take up the cartilage, and make room for the 
osseous matter, he necessary in the formation and growth, it 
is no less necessary for the life and health of the full formed 
hone. 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 earthly 
parts. The earth, which constitutes the hardness, and all the 
useful properties of bone, is dead, inorganized, and lies in the 
interstices of the hone, where 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 with new matter. The cartilage is in 
itself a secretion, to which the full secretion of 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 formation of bone (or the preparation of it) in the carti- 
lage, there is no proof of there being vessels in it. But we presume that the 
cartilage must have vessels, because it grows with the growth of the ani- 
mal, previous to the formation of bone in it. 
However, the change, previous to the deposition of bone, has not been no 
ticed: the firm cartilage sufiers a change ; there is a tract from the circum- 
ference to the centre of it, in which the firm cartilage is dissolved ; and in 
the spot where the first particle of bone is to be deposited, there is a little 
soft well of matter, different from the firm substance of the cartilage. C. B. and growth of bones. 
9 
funning together, form a perfect bone.* If the broken limb 
be too much moved during the cure, then are the secreting ar- 
teries interrupted 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 ac- 
customed 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 refuge 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 distinguish 
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 ap- 
pears in their bones, is removed, and appears again with such 
a sudden change as proves a rapidity of deposition and ab- 
sorption, 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 madder be left off but for a 
lew days, the red colour is entirely removed. 
* The matter may be thus stated : the extravasated blood being absorbed, 
an effusion is poured out by the vessels of the broken bone. This matter is a 
regular secretion, it appears to the eye like a uniform jelly; but so does the 
embryo itself. It is bone in embryo, the membranes and vessels, arteries, veins, 
and absorbents are in it; the arteries of the surrounding parts do not shoot in- 
to it, but veins, as well as arteries and absorbents, inosculate with the vessels 
of this new formed matter; and whatever vessels may, by accidental contact, 
inosculate with this substance, whether coming from bone, muscles, or mem- 
brane, still bone is formed, because it is the destined constitution of the new 
formed mass, or rather of the vessels which are already in it to form bone. C B. 10 
OF THE FORMATION 
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 foresee that 
this tinging of the lamellae 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 himself 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 grow 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 his hurry") he tells us, that by looking through 
the transparent part of a cock’s wing, he had seen the tinge oi 
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- 
ment, when trying to confirm our preconceived theories by 
experiments and facts.* 
* However just this criticism is upon the reasoning of Du Hamel, yet I be- 
lieve in the facts stated. In my Collection may be seen the bone of a pig show- 
ing three distinct layers, distinguishable in colour. C. 13. AND GROWTH OF BONES. 
11 
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-absorb the earth- 
ly particles, 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 
observation; when a carious bone disappears befoi'e the in- 
teguments 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 thigh-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 wejght of the body ; the 
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 shocking degree, gelatinous, 
or nearly so, robbed of all their earthy parts, and so tho- 
roughly softened as to be cut with the knife.* 
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 jvith its 
nutritious vessels ; and yet we dare hardly believe the demon- 
stration, since bones seem quite insensible and dead : We 
have no pain when the periosteum is rasped and scraped from 
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 
* See the examples of distortion in the Museum, Windmill Street, and in 
particular the skeleton of a woman who died in consequence of the Qxsarean 
operation. C. B. 12 
OF THE FORMATION 
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 
continually exposed to shocks and blows, and all the acci- 
dents of life ; which have to suffer all the motions which the 
other parts require. In this sense, the bones, the cartilages, 
ligaments, bursae, and all the parts that relate to joints, are 
quite insensible and dead. A bone does not feel, or its feel- 
ings 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, 
and it inflames ; burn it, and it dies : take any proof of sen- 
sibility, but the mere feeling of pain, and it will answer to the 
proof. In short, these pai*ts have a sensibility which belongs 
to themselves, but have no feelings in correspondence with 
the general system.* ■ 
A bone feels stimuli,and is excited to re-act; injuries pro- 
duce inflammation in the bones, as in the soft parts; and then 
swelling and spongy looseness, and a fulness of blood, sup- 
puration, ulcer, and the death and discharge of the diseased 
bone ensue, When the texture of a bone is thus loosened by 
inflammation, its feeling is roused ; and the hidden sensibility 
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 
increased by disease, the bones, ligaments, bursae, and all the 
* From 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 impressions to the sensorium, I have come to the 
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 
varies in different parts, and in general the sensibility of the more superficial 
parts, being sufficient protection to the parts beneath, the deep parts are but 
little sensible. The sensibility possessed by the skin would not be sufficient 
protection to the eye ; such parts differ in kind of sensibility as well as in de- 
gree. Experiments have been made by cutting and burning the bones 
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 sa 
tisfy 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 propagate that pain to the sensorium ; and further, that the pie 
culiar sensibilities are so suited as to allow of the free and natural motion and 
of the necessary degree of attrition, but are bestowed for the purpose of ma- 
king us avoid that degree of violence, which would endanger the texture or 
heajfhy function of the part. C. B. AND GROWTH OF BONES. 
13 
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 twen- 
tieth year; it is forwarded by health and strength, retarded 
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 sup- 
puration, 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 hastened, as the pelvis, that it may acquire its per- 
fect size early in life. Ossification is assisted by the softness 
of the cartilaginous bed in which the bone is formed ; by those 
large and permeable vessels which carry easily the grosser 
parts of the blood ; by a quick and powerful absorption, which 
all along 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 14 
OF THE FORMATION 
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 flac 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 
system, 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 
* The ossification of the flat bones is a subject too curious to be omitted 
in this dissertation. The brain of the foetus while of the size of a hazle nut 
is invested with a membrane in which there is as yet no speck of bone. In 
the third month, the ossification of the craniel bones commence, and the first 
process exhibits a very beautiful net of ossific wire-work. In a circle, the di- 
ameter of which is half an inch, we see a perfect net-work, resembling a fine 
lace or the meshes of a spider’s web. Upon this first layer another is deposit- 
ed, 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 are not opposite to those 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 the first, the inner layer 
is extending in threads diverging from the centre, betwixt which delicate pro- 
cesses of bone, intervening ribs are formed irregularly, still resembling the 
texture of the spider’s web ; and the diverging line of bone being the stronger, 
it appears as if the cranial bones formed in diverging radii, while the edge of 
the bone extends in fine net-work, like to the first formed speck of ossifica- 
tion 
It is further worthy of remark, that this is the texture of true bone, and that 
what are called morbid ossifications, as of the coats of arteries and other 
membranes are merely the deposite of earthy matter without organic struc- 
ture. C B. 
| The processes and heads are named the epiphysis and apophysis of bones. 
The apophysis, a process which projects from the bone and grows from it. 
The epiphysis is that portion which growing by a distinct centre of ossifica 
tion is afterwards united to the body of the bone. C. B. AND GROWTH OF BONES. 
15 
fibres stretch towards either end, and stop there (fig. 1. plate 
I.); then it begins to appear that the heads and body are 
distinct parts ; the fibres of the growing bone have extended 
till the cartilage is annihilated, and only a small plate remains, 
separating 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 continue 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 hol- 
low, on the surface of the epiphysis, or separated head, and a 
rough convexity on the end of the body: they are finally uni- 
ted into one bone, about the twentieth year. 
In the original cartilage, there is no hollow nor cavity; it 
is all one solid mass. Fig. 1. plate II. When the ossifica- 
tion first appears, the cavity of the bone also begins, and ex- 
tends 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, contain- 
ing the trunks and branchings of the nutritious vessels, which 
enter by a great hole, in the middle of the bone ; and the ca- 
vity is traversed, with divisions of its lining membrane, which, 
like a net-work of partitions, conduct its branches to all parts 
of the internal surface of the bone; and its nets, or meshes, 
are filled with 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 
lamella?, 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 towards its cavity: and these plates, being again 
crossed by small bony partitions, form a net-work, or spongy 
mass, which fills the whole cavity of the bone. In the mid- 
dle 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 also is 
Targe ; but it is not like that in the middle, a large tabular 16 
OF THE FORMATION 
cavity: it is so crossed with lattice-work, with small intersti' 
ces and cells, that it seems all one spongy mass of bone ; and 
so many of the inner layers are separated, to form this profu- 
sion of cells, that the whole substance of the bone has degene- 
rated into this lattice-work, leaving only a thin outward shell.* 
This 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 cavi- 
ties, 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 marrow 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 mi- 
croscope, 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 beautiful- 
ly on the surface of the bag, and serves to secrete the mar- 
row, each small twig of artery filling its peculiar cell. To 
this, an old anatomist added, that they had their contractile 
power, like the urinary bladder, for expelling their contents ; 
that they squeezed their marrow, by channels of communi- 
cation, through and among the bony layers; and that their 
oil exuded into the joint, by nearly the same mechanism, by 
which it got into the substance of the bone. 
While 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 lamella? 
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 olf, 
* That it is merely an expansion of the layers which forms the cancelli, and 
a mere swelling and sponginess of the same quantity of bony substance, which 
makes the ends so mucli thicker than the middle, is proved by this, that an 
inch of the smaller bony tube, cut from the middle, weighs equally with an 
mch of the large spongy tube, cut out from the ends. AND GROWTH OF BONES. 
while another is entire and sound. Malphighi had first ob- 
served the lamellated 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 found 
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 offices of nails : these appeared to his 
imagination to be of four kinds, straight and inclined nails, 
crooked or hook-like, and 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 through 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 anato- 
mists imagined them to be still more important, allowing the 
matter to transude through all the substance cf 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 inter- 
nal parts of the body is very mechanical, and very ignorant; 
for the enternal 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 watered with arteries; 
it is moist in itself, and cannot be further moistened nor lu- 
bricated, unless by a fuller and quicker circulation 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. Every 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 moistness of a bone, than for preventing brittleness 
17 
* Notwithstanding what is here delivered, there is no proof of the hones being 
lamellated ; as to the exfoliation of bone, the dead portion is more generally ir- 
regular in its thickness, and rugged on its inner surface. This exfoliation of bone 
is a process of the living bone, and the inner living surface recedes from the outer 
one, because that outer surface is injured or dead. The nature of the injury, or 
the depth to which the bone has become dead, determines the extent and form of 
the portion cast off. When a scale only is thrown off, it is because the bone is onlv 
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 stones or met- 
als exposed to the influence of the air, and moisture, and varying temperature : 
the thickness and succession of exfoliations depends on the operation of the wea- 
ther, not on the original formation of the bone. I have never seen heat produce 
a lamellated decomposition of bone. C. B. 
| These nails Gagliardi imagined were no more than the little irregularities, 
risings, and hollows of the adjoining plates, by which they are connected. 18 
in the eye. This marrow is, perhaps, more an accidental 
deposition than we, at first sight, believe. We indeed find 
in it such a regularity 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 
connot entertain the absurd notion, of fat being needed in our 
old age, to lubricate the bowels or the heart; no more is the 
marrow (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 secrete 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; 
particularly large arteries enter into the heads of the holes, as 
of the shoulder or of the thigh bones; and there the perios- 
teum 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 mem- 
brane, and of the bone, are seen covered with bloody points; 
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 by the absurd 
name of internal periosteum; 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 drawm 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 
connexion and office is so essential to the life and health of the 
bone, that the spina ventosa, or scrophulous bone, is merely a 
OF THE FORMATION 
* If we look to the 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 fila- 
ments'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 to pressure, it is firm, where it lies concealed, it 
is less so ; but where it is altogether within the protection of the bones, the 
membranes are very delicate, and the fat takes the appearance of marrow. C. B. AND GROWTH OF BOXES. 
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 
our 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 connexion of the periosteum, tendons, ligaments, fasciae, 
and bursae, 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 of 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 medullary 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 peri- 
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 ventosa is the consequence of abscess in the cavity of the bone. See the spe* 
-dmcns in my collection. C. B. 20 
OP THE FORMATION 
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 off 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 the cartilage to generate 
bone, we cannot in reason, suppose 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. | 
• It is the injury to the surface of the bon« which causes the exfoliation, not the 
loss of vessels by the separation of the periosteum; and when the bone dies, as 
in necrosis, from the injury to the marrow, inflammation precedes the death. C. B. 
t This is true as a physiological fact, but it is not the proper method of curing 
wais defect of union in a bone. Seethe 2d vol. of Operative Surgery bv C. 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, 
maintained 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 hu- 
mours 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 to 
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 removed; to bear all the shocks of leaps or 
falls; to perform all the motions of the body, and the con- 
tinual workings of the joints, where they rub, and even crackle 
upon each other without danger or pain. 
We now understand the constitution of a bone, and can 
compare it fairly with the soft parts in vascularity, and in 
feeling; 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 arteries 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 bony matter, that the composition may neither be too brit- 
tle nor too soft. From this constitution of a bone, we could 
easily foresee how the callus for uniting broken bones must be 
formed; not by a mere coagulation of extravasated juice, but 
by a new organization resembling the original bone. 
The primordium 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 spread from point to point, till 
the mucus is animalized and converted into a membrane : and 
thus the heart, the intestines, the testicle, and other parts, ad- 
here by inflammation to the coats which surround them, and 22 
ll V TIIE FORMATION 
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 grad- 
ually depositing nuclsei 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 nuclasi 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 
peculiar 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 sub- 
stance of the bone itself: but I have been employed in explain- 
ing, 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 
spoiled 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 anato- 
mist 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 surrounds the bone, and the marrow within. In the experiments and ob- 
servations which I have made, neither the periosteum or marrow seemed to have 
formed the bone ; and I conclude, that nothing but bone can form bone, by the 
continuation of natural actions ; and that in the case of necrosis, the old bone in- 
flames and begins the new formation, before the continued irritation in the cen- 
tre kills it. C. B. AND GROW TH OF HONKS. 
23 
stroy 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 vascu- 
lar 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 uni- 
tedly 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 structure, 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 
III. fig. 1. When I 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 consequence of the destruction of the vessels of the periosteum, 
but of the contact of foreign matter with the surface of the bone. An effect pre- 
cisely similar is the consequence of the sloughing of the soft parts over a bone, for 
the dead slough lying on the surface of the bone causes an exfoliation. 
The effect of injury to a living bone is very curious. But the manner in which 
the bone resumes its pristine form is still more worthy of observation. At first 
the outward exfoliation 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 bone contracts its 
diameter, and the cavity becomes of its natural dimensions so that the evidence of 
the changes which the bone has undergone are quite removed. This is a very' 
beautiful example of the influence of that principle which controls the growth of 
all the parts of the body, which may have its operation deranged by violent injury 
or by disease ; but which will at last by slow degrees restore the part to its natu- 
ral form and action. C. B. . 24 
CHAP. II. 
OF THE SKULL IN GENERAL—THE BONES OF WHICH IT 13 
COMPOSED THEIR TABLES DIPLOE—SUTURES THEIR 
ORIGINAL CONDITION, AND THEIR PERFECT FORM, REPRE- 
SENTED AND EXPLAINED. 
While the bones in general serve as a basis for the soft 
parts, and supporting and directing the motions of the body, 
certain bones have a higher use in containing those organs 
whose offices are the most essential to life. The skull defends 
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 the 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 of 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 
surface is composed of many small bones, from the cranium 
or skul-cap, where a few broad and flat shaped bones form 
the covering of the brain. It is these chiefly which enclose 
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 thought 
to be thicker, more spongy, less easily broken ; the inner ta- OF THE SKULL IN GENERAL. 
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 cancelli, 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 without, 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 pericranium spoils the bone, separates the dura mater, 
and causes effusion upon the brain : a separation of the dura 
mater is, in like manner, followed by separation of the peri- 
cranium, which had been sound anti unhurt ; and every dis- 
ease of the cancelli, or substance of the bone, is communicated 
both ways ; inward to the brain, so as to occassion very immi- 
nent 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, 
25 
* 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 I shall often 
have occasion to use. 
j There is a state of inflammation, either under the dead bone or in the sur- 
rounding bone, which gives extreme pain, even when the silver probe touches the 
dead bone, C. B. 26 
OF THE SKULL IN GENERAL. 
the skull has its proper arrangement of cancelli and tables ; 
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 
tables 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 
performed quickly and safely at once. But, besides this gra- 
dual progress of a bone increasing in thickness and regularity, 
as life advances, and grow ing irregular and thinner in the decline 
oflife, 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 foveae, 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 ; 
so that in those places where the skull should be most regular, 
we are never sure, and must, even in the safest places, perfo- 
rate 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 the words calva or calvaria from calvis, bald, or sometimes cerebri 
galea as being like a helmet to protect the brain. 
We find some terms distinguishing certain parts of the cranium as glabella the 
smooth part in the centre and. lower part of the forehead. Occiput the utmost 
convexity of the head backward. Vertex, the crown of the head where the hairs 
turn. Bregma, or fontanelle, which are terms derived from very false notions, 
hut 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 description can be given in plain English. 
The following is the usual division of the hones of the head. 
Of the Cranium, 
Six Bones. 
1 Os Frontis 
2 Ossa Parietalia 
2 Ossa Temporalia 
1 Os Occipitis 
In the adult head there are thirty bones and thirty-two teeth. 
Intermediate or 
Common Bones, Two. 
1 Os Sphenoides 
1 Os Ethmoides 
>y 
Bones of the Face, 
Fourteen. 
2 Ossa Maxillaria Supra. 
2 Ossa Malarura 
2 Ossa Nasi 
2 Ossa Palati 
2 Ossa Unguis 
2 Ossa Turbinata Infa. 
1 Vomer 
1 Ossa Maxillaria Infa; 
Bowes of the Eau, 
Four on each Side. 
Maleus 
Incus 
Os Orbiculare 
Stap.es 
Teeth, Thibtt-two. 
8 Incisores 
4 Cuspidati 
8 Bicuspides 
12 Mol a res 
32 OF THE SKULL IN GENERAL. 
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 forepart 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 part of 
the head ; and are named parietalia, as they are the walls or 
sides of the cranium. 3. The os occipitjs, 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 ol the cranium : they are called temporal, from the hair 
that covers them being the first to turn gray, marking the time 
of life. 5. The os vEthmoides, and, 6. the os sphenoides, 
are quite hidden in the basis of the skull: they are very irre- 
gular and very difficultly described or explained. The os i£TH- 
moides, is a small 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 aethmoid plate. The os sphenoides 
is larger and more irregular still; placed further back ; locked 
in betwixt the occipital and aethmoidal bones ; lies over the 
top or 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 ol the brain, and transmit almost all its 
nerves. 
SU'l URES.—All these bones are joined together by seams, 
which, from their indented, or dove-tailed appearance, are na- 
med sutures.* 
27 
* Suture is a common term for tlie line of contact of the flat bones. It is a 
form of union admitting; of no motion, and is somewhat varied according to the 
degree of pressure they have to sustain. They may be arranged thus: 
JlINCTlTRA ImMOBJLIS. 
1. Sutura Vera—Serrata.—Dentata, 
2. Sutura Spuria •—Linea—Harmonia. 
3. Sutura Squamosa—Limbosa, 
4. Gomphosis. 
.Monro (Anatomy of the Human Bones) expresses the common opinion, that 
“ the suture is formed by the two bones meeting while they are thus flexible and 
“ yielding, and have not yet come to their full extent of growth, so that they mu- 
tually force into the interstices 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, &©.” I object to this, because it represents the suture to be an 
accident. Are not all bones pushed together as here described ? yet the true su- 
ture 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 consequence of this is, that sutures are 
formed when their margins unite. But why is there this variety in the form of 
the juncture ? Certainly this is not accidental. We must notice that when a bone 
js light and weak it is united by the simple line of contact, or what is'called by 
i armonia. On the_contrary, where the bone has to bear pressure, or where it has :< 28 
OF THE SCULL IN GENERAL. 
1. The coronal suture, is that which 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 lambdoidal 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 arrow 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 the temporal 
bone ; and so has been named sometimes, additamentum su- 
turse lambdoidalis ; sometimes additamentum suturse squamo- 
sae : for this temporal suture is, on account of the edge of the 
temporal and occipital bones being thin, and like scales of ar- 
mour laid over each other, often named the squamous or scalv 
suture. 
5. The sphenoidal and sutures, are those 
which surround the many irregular processes of these two 
bones, and join them to each other and to the rest. 
more important organ to protect, it is thick and firm, and it is joined by the in- 
dented suture, which is a union by a more perfect mechanism, and gives strength 
proportioned to the bone. Thus we see that the bo.ies of the craninm are united 
hy the true suture. But the most perfect specimen of the true suture will be found 
m the skulls ot horned cattle, because this instrument of defence must be reared 
on a firm foundation. 
1 urther, the anatomist repeats from day to day and year to year, that the 
squamous suture is made by the pressure of the temporal muscle ; an accident 
agaiji. No : it is formed for a purpose, it is the kind of suture the best calculated 
to bind in the cranial bones, and to prevent the starting of the parietal bones. He 
does not contemplate the structure of the body in a proper temper of mind, who 
looks upon these admirable 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 serrse 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 untoucjied. 
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 which 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 
Wormania) surrounded with pecuiar 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 grisly-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 lor 
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 centre 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 cancel'll 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 parietali a have one great and promi- 
nent point of ossification in the very centre of each, from 
which diverging rays of ossification extend towards 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 9mall QP THE SHULL 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 
TRiquETRA, or triangularia from their angular shape, or, 
wormian A, from Olaus Wormius, 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; 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, an 1 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 which 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, fthough they are formed in distinct points, 
and are 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 
or THE SKULL IN 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, wrere we dare not follow them with the knife, nor ap- 
ply the trepan. Indeed we do not even know that limiting the 
extentof fractures could be a gracious provision of nature, since 
it would rather appear by the common accidents, that the 
more easily the bone 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 connexion betwixt 
the external and internal membranes of the skull, and they 
thought that nature had intended there a freer communication, 
and 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 bregma, foils, fontanella, 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 arid surest drain ; and after a curious examination 
of each, he decidedly condemns the fontanelle; finds the ad~ OF THE SKULL IN GENERAL. 
33 
ditamentum 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 
pulsation behind the ear: upon applying the finger, a strong 
beating was felt; the part was soft and yielding; and upon 
opening his head, after death, there was found a large mem- 
branous space. Diemorbrock found the fontanelle open in a 
woman of forty years of age. Baubin 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 lor 
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 con- 
tract 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 swel- 
ling 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 instances 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 
44 a man of forty years of age, being in the dog days, seized 
44 with a raging fever, delirium, watching, and dreadful pains 
44 of the head, his sutures opened on the seventh day, were 
44 as wide as in a child, not only so as to be distinguished hy 
44 the finger, but that the attendants could see the pulsations 
of the brain: the fever, after some time, abated; the 34 
OF THE SKULL IN GENERAL. 
a 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 
parted 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 had 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 ol 
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 pe- 
culiar uses may be found. We cannot pass unnoticed their 
looseness and flexibility in the new-born child ; how wonder- 
fully the head of the child is increased in length, and reduced 
in breadth in the time of delivery, and how muth this con- 
duces 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 ea- 
sily 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 warmer 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 dis- 
tinguished from those who had submitted to the Spanish yoke ; 
or of what is told so often of eastern nations, that they some- 
times mould the heads of children into monstrous and uncouth OF THE SKULL IN GENERAL. 
35 
forms, 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 by 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 
pelvis relaxed or dissolved without pain and danger, confine- 
ment for many months, a temporary lameness, and sometimes 
she is rendered unable for life. 
CHAP. III. 
DESCRIPTION OF TIIE 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 caverns, 
named the sinus (or cavites) of the frontal bone. Its orbitary 
plates are the two thin and delicate lamellae that depart 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 sup- 
porting the lower part of the brain ; and these two orbitary 
plates leave an open space, in which is incased the chief part 
of the sethmoid bone, viz. incissura aethmoidea. 
The frontal bone stands connected with the parietal bones 
by the coronal suture ; it is connected to the great ala of the 
sphenoid bone by the sutura spheno frontalis ; while its orbi- 
tary 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 
aethmoidea frontalis, and looking into the orbits the same on 36 
DESCRIPT10N OP TUB 
bitary plates are seen to be contiguous to the ossa plana and 
ossa unguis ; and, lastly, the ossa malarum 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 the eye-brow 
which it supports: over this line the integuments are loose: 
here many arteries perforate the bone, which are properly the 
nutritious 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 the 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 the bone, it forms a notch ; but most commonly, in place 
of turning fairly 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 which comes from the eye to go out upon the fore- 
head is named, where it passes, the superciliary artery; and 
higher up upon the forehead, the frontal artery: it establishes 
a communication betwixt the internal arteries of the eye, and 
external arteries of the forehead and temple. We are alwavs 
warned of the danger of wounding arteries where they pass 
through bones; and strange stories are told of the terrible 
bleedings which have arisen 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 delivered 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 
transmits a small vessel from the orbit to the nose. 
The orbitary, or superciliary ridge, ends by two processes, 
which, forming the angles of the 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 eve. 
Betwixt the two internal angular processes there is the na- INDIVIDUAL BONES OF THE SKULL. 
37 
SAL point or process. This nasal process is a small sharp 
projecting point, occupying that space which is exactly in the 
middle of the bone, and is betwixt the two internal angular 
processes. 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 abso- 
lute mark of the presence of these sinuses, which often, in the 
flattest foreheads, are not easily 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 larger 
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 
partition 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 
traih of cells, which, commencing thus in the frontal bone, ex- 
tend through the sethmoidal, 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 sinus is used in two senses : we call the cavities or cells, within 
the substance of a bone, the sinuses of that bone: as the sinuses of the forehead, 
of the sphenoid, acthmoid or maxillary bones : we call also certain great veins 
by the same name of sinuses ; thus the great veins being enlarged where they 
approach the heart, and the veins being particularly large in the brain and the 
womb, we call them the sinuses of the heart, of the brain, 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 know 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 en- 
tirely closed; or when, by venereal ulcers, the curtain of the 
palate is consumed, no part of the voice passing upwards in- 
to 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 mistake 
lies in 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 pre- 
maturely developed with bushy hair upon the pubes. This man-child 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 Linnaeus, 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, assafcetida, 
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 may be 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,u 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 hold 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 hold. 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 through 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 Surgery, 
4to. vol. ii. 40 
DESCRIPTION OF THE 
The orbitary process already described is the most re* 
markable point of the frontal bone. The orbitary processes 
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 exquisite- 
ly 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 of 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 where 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 
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.f It has deeply ser- 
rated edges, which unite the two bones with each other, and 
with the occipital and frontal bones. All the coiners 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 
* In addition, as points of demonstration, we may add the eminenticc froufaie s, 
and supcrciliarcs. 
| It enters into the corona!, the sagittal, the lamhdoidal, and the squamm. • 
sutures. INDIVIDUAL BONES OF THE SKULL. 
41 
regular 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 par- 
ticularly white and hard ; and rays extend downwards from 
this, converging towards the jugum. The white semi-circular 
line represents the origin of the temporal muscle; and the 
converging 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 where 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 
mastoidean 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 mois- 
ture from the brain; and so the parietal bones are named 
ossa bregmatis. 
* The word pulsatilis, or fans pulsatilis, or beating fountain, was added, be- 
cause we feel the beating of the arteries of the brain there. 42 
DESCRIPTION OP THE 
OS OCCIPITIS, has also the names of os memorise, 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 the lambdoid 
suture, to the mastoidean portions of the temporal bone by 
the additamentum suturse lambdoidalis, 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 in- 
sertions of the muscles, projecting lines are on the bone. In 
the middle of the bone, and betwixt the muscles of opposite 
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 prominent, 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 tentorium cerebello super-exten- 
sum, is a diaphragm or transverse partition, which crosses the 
skull at its back part; cuts off from the rest of the cranium 
the hollow of the occipital bone, appropriates that cavity for 
the cerebellum, and defends the cerebellum from the weight 
and pressure of the brain. This tentorium or transverse 
membrane, is attached to the great internal iudge 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 beginning the demonstration, we point out its divisions : 1. Pars occipi- 
talis. 2. Pars lateralis or condyloidea. 3. Pars basilaris or cuniformis; which 
at birth are distinct bones divided 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 branch- 
es 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 triangular or tripod-like groove, which fol- 
lows the internal ridges of the occipital bone : and above and 
below 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 oc- 
cipital 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 off 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 lower part of the cuniform process, there are two 
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 44 
DESCRIPTION OF THE 
smoothed ; a little thicker at the lip, and having a roughness 
behind that giving a firm hold to a ligament, which, depart- 
ing 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 before 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 occi- 
pital 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 squamosa 
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 rub- 
bing of the temporal muscle. The pars petrosa, often 
named os l apidosum, or stony bone, is hard, irregular, rocky; 
just inwards towards the basis of the skull; contains the or- 
gans 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 su- 
ture ; is scolloped or fringed; and exceedingly thin on its edge; 
it is radiated, in consequence of its original ossification shoot- 
ing out its rays. The petrous part again is triangular, une- 
qual by the cavities of the ear; it has a very hard, shining, 
polislied-like surface ; exceeded in hardness by nothing but 
* The interior and posterior Semi-circular canals are protuberant upon its 
surfaces. INDIVIDUAL BONES OF THE SKULL. 
45 
the enamel of the teeth. Where it projects into the base, it 
has several open points, which are filled up with cartilaginous 
or ligamentous substance ; and its occipital angle is connected 
with the other bones by the additamentum suturse squamosse. 
The temporal bone closes the cranium, upon the lower and 
lateral part; backwards it is connected by the additamentum 
suturse lambdoidalis to the occipital bone; by the squamous 
suture and the additamentum suturse squamosae, it is joined to 
the parietal bone; whilst anteriorly it is united to the sphe- 
noid bone by the spheno-temporal suture, the spinous process 
of the sphenoid bone being deeply wedged betwixt the pe- 
trous and squamous 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 with it a zygoma, 
yoke, or arch of the temple, under which the temporal mus- 
cle plays. The temporal muscle is strengthened by a firm co- 
vering 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 lower edge of the zygoma, 
particularly one named masseter, which moves the jaw ; and 
one named zygomaticus, or distorter oris, because it draws 
the angle 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 en- 
graved their writings on tables of wax. It is cartilaginous 
long after birth; even in the adult, it is not completely form- 
ed ; it is exceedingly delicate and small; and when its carti- 
laginous 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 muscles, chiefly of the throat and jaws. One slender 
muscle going downwards from the styloid process, and ex- 
panding 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 backwards 
and upwards, raising 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 have named vaginalis, as if it resembled a sheath 
for the styloid process. 
Mastoideus or mammillaris, is a conical nipple-like 
bump, like the point of the 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 ca- 
vity 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 mus- 
cle ; 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 process 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 by 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 from 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 by a shallow 
fossa, which is anterior to the auditory process, and at the 
root of 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 car- 
tilage of this articulation. This fissure divides the proper 
articular or glenoid cavity from that fossa which gives lodge- 
ment to a deep portion of the parotid gland. 
Holes. 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 meatus auditorius externus (the circle of which 
has been described) 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 auditorius internus 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 
comes 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 sty- 
loid process; and being betwixt the two, it is named the sty- 
eo-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 iter a p al ato 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 mav 
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 artery, 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, when 
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 artery 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 
arteries; and Haller is at pains to inform us, that, during a 
fever, he felt this beating in a very distressing degree. 
The great lateral sinus comes out in part through the 
temporal bone, to form the internal jugular vein. The course 
of the sinus may be easily traced by the groove of the occipi- 
tal 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, hut by what is 
called a common iioli, vi?.. 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 divided 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 jugu- 
lar 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 
sinus. 
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 suturse squamosae). Some- 
times it is in the occipital bone ; or sometimes it is wanting: 
it transmits a trifling vein from without, into the great sinus, 
©r a small artery going to the dura mater. 
There are two very small canals, which probably carry lym- 
phatics from the inner cavities of the ear; they have been cal- 
led aqueductus vestibuli, and aqueductus cochleae; 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 fossae, 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 arterv of the dura mater. 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, be- 
twixt 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, receive 
the divided nerves, and give them an opportunity of expand- 
ing into the organ of smelling ; and these bones, upon which 
the olfactory nerves are spread out, «*•© o© much convoluted, 
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 seth- 
moid 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 sethmoid is united to the 
frontal bone, by the linea sethmoidea frontalis, and to the 
sphenoid bone by a similar line of contact, visible on the in- 
side 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. 
The plate is horizontal; but its processes are perpendicular, 
one above, and three below’. 
The first perpendicular process is what is called christa 
galli, a small perpendicular projection somewhat Tike 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 opposite to this, and in the same direction with it, 
(i. e.) perpendicular to the aethmoid plate, stands out the 
nasal plate of the aethmoid 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 commonly inclined a little to one or other side, so 
as to make the nostrils of unequal size. The azygous pro- 
cess is united with the vomet, which forms the chief part of 
the partition; 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 pro- 
jecting part of the nose ; but the cartilage rots away, so that 
whatever 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 cover- 
ed with a delicate and sensible membrane, and when the olfac- 
tory nerves depart from the cribriform plate of the aethmoid 
bone, they attach themselves to the septum, and to these upper 
spongy bones, and expand upon them so., that the convolu- 
tions of these bones are of material use in expanding the organ 
of smelling, and detaining the odorous effluviae 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 convolutions, 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 
DESCRIPTION OP THE 
The os unguis should also, perhaps, be counted as a parf 
of this bone; for though the os unguis, when observed in the 
orbit, seems to be a small detached bone, 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 aethmoid 
bone, comes along with it when we separate the pieces of the 
skull, and when the os unguis is pared off from the aethmoid 
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 aethmoid bone, which form so important a 
share of the organ 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, parted 
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, 
we can easily understand how the venereal ulcer, when deep 
in the nose, having got to these cells, cannot be cured, but 
undermines 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 effects of a fractured skull, and 
without any operation which could give relief. And we also 
see much danger in pulling away 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- 
niform, or wedge-like bone, from its being incased in the 
very basis of the skull; or it is named os multi forme, 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 
* The number is commonly twelve, blit not regularly so. INDIVIDUAL BONES OP THE SKULL. 
53 
pterygoid bone, its temporal processes being like extended 
wings; its proper pterygoid processes like feet; its middle 
like the body and head 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 the 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 the processes can be referred; so that we are al- 
ways, in describing this bone, moving forwards from point to 
point, from one processs or hole to the next. 
PROCESSES.—The alal, or wings, 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 
the frontal, parietal, and temporal bones, by a thin scaly edge, 
they make part of the squamous suture, and give a smooth 
surface 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 sethmoid 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 orbitary process of the vphe- 
noid bone, or orbitary 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 the 
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 the 
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. 
The lesser wing of Ingrasias 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 the sethmoid bone. 
This lesser wing projects laterally into the transverse spi- 
nous process. 54 
DESCRIPTION OP 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 o? the pterygoid process, is called 
the hook of the palate, of which it forms the backmost point. 
The musculus circumflexus 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,! is so named, from its being single, 
because it is seated in the centre of the bone, so that it can 
have n> 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 clynoid 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 is some confusion in this name, since pterygoid signifies aliform, or 
wing-like processes. 
| Rzygous is a term, which is applied to such parts as have no fellow; be- 
cause almost always the parts on one side of the body are balanced by similar 
and corresponding parts on the other side. When they stand in the centre of 
the body, or are otherwise single, we call them azygous, and so the azygous pro- 
cess 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 ti.yir points; and 
they look forwards towards the anterior clynoiOprocesses. 
The tuberculum olivare is an eminence betvixt the an- 
terior clynoid process and before the sella turcica. 
The SELLA turcica ephippum, or Turkish sadde, 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 carotd ar- 
teries rise up by the sides of the sella turcica, and maik its 
sides with a broad groove. The optic nerves lie upon a groove 
at the fore part of the sella turcica, betwixt 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 distinguished; 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 ob* 
scurity, when the bones are in union, and in separating the 
sphenoid bone it is very7 apt to be broken off. This process 
closes the cell, and projects laterally towards the deepest part 
of the orbit, but so as to be concealed by the palate bone. 
This bone has also its cells, for all that part which 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 mid- 
dle 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 aethmoid cells, it probably per- 
forms one office with them, is almost a continuation of them, 
so that when any one is less or wanting, the others are pro- 
portionally larger. 
HOLES.—The sphenoid bone is so placed in the very cen- 
tre 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 foremen l acerum, is next in order, and is so named, 
because it k a wide slit. It is also called superior orbitary 
fissure. foramen lacerum is wide near the sella turcica, 
grows gradually narrower as it goes out towards the temple, 
till it ttfndaates almost in a slit. The upper line of the fora- 
men licerum 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 
5;h 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, 5th, 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 appropriated 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 5th 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 this 5th pair passes through 
the foramen lacerum to the eye; the second branch of the 5 th 
pair passes through the foramen rotundum to the upper jaw ; 
ihe third branch of this great nerve passes through the fora- 
men ovale to the lower jaw ; and if we had any faith in the 
doctrines 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 foramen ovale is an oval hole, larger than the fora- 
men rotundum ; about half an inch behind it; and transmit- 
ting the third branch of the 5th pair to the lower jaw. 
The foramen spinale, or 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. 
57 
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 oi 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 way, gives a small branch, to help out the slender begin- 
ning of the great sympathetic nerve. This retrogade 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 pterygoid hole :* or by many, is named 
after its discoverer, the Vidian iiole.| 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 the 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 comon hole betwixt 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 the little nerve, which perforates the os petrosum 
on its forepart. 
f Vidus Vidius, a professor of Paris, and physician to Francis the First, 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; 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; but 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 NASI.—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 ; 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 another, 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 their lowest 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 call- 
ed, the bridge) of the nose ; from which connection, notwith- 
standing 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 cavi- 
ty to give attachment to the nasal plate of the rethmoid bone. 
Os unguis, so named from its being of the size and shape 
of the nail; or sometimes named the os laghrymale, from 
its holding the duct, which conveys the tears, is that thin scale 
of bone which I have described as belonging to the os seth- OF THE FACE AND JAWS. 
59 
moides. It is commonly described as a distinct bone; it is a 
thin flat bone, a single scale, without any cancelli, having on- 
ly one sharp ridge upon it; it forms a groove for lodging the 
lachrymal 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 na- 
sal 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 and easily broken, being 
as thin as a sheet of paper. It is tnis bone which is pierced 
in the operation for the fistula lachrymalis, which is easily 
done, almost with a blunt steel or probe ; and the chief cau- 
tion is to perforate in the place of the groove, as that will lead 
into the nose, and not behind it, which would carry the per- 
forating instrument 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 max- 
illary 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 foun- 
dation or basis of the face. They send a large branch up- 
wards which forms the sides of the nose ; a broad plate goes 
backwards, which forms the roof of the palate. There is a 
circular 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 
determine the height of the cheek bone and the form of the 
Tace; and the diseased enlargement of this cavity raises the 
cheek bone, lessens the eye, and deforms the face in a very 
extraordinary 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 or na- 
sal; The inferior or palatine. 
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 sethmoid bones; 
towards the nasal cavities, it has the vomer palate-bone and 
lower spongy bones attached to it, and at the back part it 
touches the sphenoid bone. 
The first process is the nasal process, which extends up- 
wards to fonn the side of the nose. It is arched outwards, to 
give the nostrils shape. Its sides support the nasal bones; 
and the cartilages of the alae 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 attachment 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, named 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 upon 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 
very7 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 upper 
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 (pro- 
cessus alveolar is,) 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 by7 
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 off 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 bones are opposed to each other in the middle of the 
palate by a broad flat surface, which cannot be seen but by 
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 neither easily separated, nor ea- 
sily 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 maxilliary bones conjoined, forming almost 
the whole of the palate, tvhile 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 with 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 par- 
ticular 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 palate. 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 antrum maxillare, or cavity of the jaw-bone, is 
commonly named antrum highmorianum,after its discover- 
er, 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 to- 
wards the cheek, but it has a flat side towards the nose ; it is 
divided from the cavity of the nostril by a flat and very thin 
plate of bone ; it seems in the naked skull to have a very wide 
opening; but in the skull, covered with its soft parts, we find 
the antrum almost closed by a membrane which stretches over 62 
OF THE BONES 
the opening, and leaves but one or two very small holes, of the 
size of the smallest pea, by which, perhaps, the reverberation 
of sound in the antrum is more effectual 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. Some- 
times by cold or other accidents, inflammations and swellings 
of the membrane come on; the holes are closed; the drain of 
matter 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 fre- 
quent : then the cheek rises; the face is irrecoverably de- 
formed. 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 uncertain. There is no very sure mark of this disease; 
it may be known by an attentive retrospect of all the circum- 
stances. The disease is not to be easily nor certainly disco- 
vered ; 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 suspi- 
cious signs. The pulling of the second or third of the grind- 
ing teeth, often brings a splinter away with it, which opens a 
road for the matter to flow ; or though there be no breach of 
the socket, often the confined matter follows the tooth, because 
not unfrequently 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 intro- 
ducing 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 some- 
times 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 bones, it forms four more: The in- 
era-orbitary hole, for transmitting the infra-orbitary nerve 
from the bottom of the eye, is the opening of the canal which 
cornea along under the eye. It is just under the margin of the 
orbit, or sometimes the nerve which it transmits, divides, and 
makes 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 is 
betwixt the two bones in the fore part, or beginning of the 
palate-suture behind the two first cutting teeth. This hole is 
named foramen 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 towards the mouth; but towards the nose, it has two 
large openings, 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 an- 
terior 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 pala- 
tine holes. The use of the anterior palatine hole has long been 
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, 
taking 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 SPIIENO MAX- 
ILLARY fissure, is a slit formed by this bone and the sphe- 
noid 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 towards the bottom of the sock- 
et, and is for the accumulation of fat, rather than for the trans- 
mission of nerves; and it is from the wasting of this fat, 
taken back into the system, that the eye sinks so remarkably 
in fevers, 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 64 
OF THE BONES 
of the upper jaw. There is a trifling hole for the transmis- 
sion 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 back- 
wards. 
The parts of the palate-bone are these f* 
The palatal plate, or process of the palate-bone, whence 
, it has its name, lies horizontal in the same level with the pa- 
latal 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 pa- 
late 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, following 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 velum, 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 
sphenoid bone, it is therefore named the pterygoid process 
of the palate-bone: but it is so joined with the ptergoid pro- 
cess of the sphenoidal bone, that they are not to be distin- 
guished in the entire skull. The posterior pterygoid hole, or 
third hole of the palate, is just before this point. 
The nasal plate, or process, is a thin and single plate ; 
rises perpendicularly upwards from the palate ; lies upon the 
side and back part of the nostrils, so as to form their opening 
backwards into the throat; it is so joined to the upper jaw- OF THE FACE AND JAWS. 
65 
bone, that it lies there like a sounding-board upon the side of 
the antrum Highmorianum, and completes that cavity form- 
ing 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 orbita- 
ry process ; or, as the knob has two faces looking two ways 
in the orbit, 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 small, and very deep 
in the socket, is not easily discovered in the entire skull. 
This orbitary process 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 
sphenoid and palatine cells of each side constitute but one 
general 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 aethmoides ; 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 inferiora are two bones, much roll- 
ed 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 in- 
decent 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 
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 
subject 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 
bones, by which it is hung upon the edge of the antrum max- 
illare; 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 end 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 
spongy 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 polypi arise 
from the upper spongy bone, we can use less freedom, and 
dare hardly pull them away, for fear of injuring the cribri- 
form plate of the xthmoid bone. We are indeed not absolute- 
ly prohibited from pulling the polypi from the upper spongy 
bone ; but we are more at ease in pulling them from the lower 
one, sinqe it is quite an insulated bone. When peas, or any 
such foreign bodies, are retained in the nose, it must be from 
swelling, and being detained, among the spongy bones. 
The spongy bones are not absolutely limited in their num- 
ber ; there is sometimes found betwixt these two a third set of 
small turbinated bones, commonly belonging to the aethmoid 
bone. 
VOMER.—The nose is completed by the vomer, which 
is named from its resemblance to a plough-share, and which 
divides 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 
aethmoid and sphenoid bones : thus it stands very firm and 
secure, and capable of resisting very violent blows. 2. Upon 
its lower part its groove is narrower, and receives the rising 
line in the middle ol the palate-plate, where the bones meet to 
form the palate suture. At its forepart it is united by a rag- 
ged surface, 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 receives 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 arq OF THE FACE AND JAWS. 
67 
all firmly connected, and covered by one continuous mem- 
brane, which is thick and strong, and that this is as a perios- 
teum, or rather like a continued ligament, which increases 
greatly the thickness 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 apprehension, when it happens to be first observed. 
OS MALiE, or the bone of the 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 the 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, be- 
cause it stands out quite insulated, and goes outwards and 
backwards to unite with the temporal bone, forming the zy- 
goma 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 surface 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 crescent, 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 jaw, of glands, muscles, blood- 
vessels, and nerves, that it were endless to give even the 
slightest 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 an- 
gle ; 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 
OF THE BONES 
line, and by feeling the crashing bones when the fallen part is 
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 can- 
not 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 
articulated 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 particu- 
lar importance, the coronoid or horn-like process, for the in- 
sertion of its strong muscles, especially, of the temporal mus- 
cle, and the condyloid or hinge process, by which it is joined 
with the temporal bone. 
The coronoid process, named from its resemblance to 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 de- 
fended by the temporal arch, and so covered by muscles that 
it cannot be felt from without. 
The condyloid process, or the articulating process 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 ar- 
ticulating head, is not round, but flat, of a long form, and set 
across the branch of the jaw. This articulating process is re- 
ceived into a long hollow of the temporal bone, just under the 
root of the zygomatic process ; so that by the long form of 
the condyles, 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 necessary 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 processes forms what is called the semi-lunar notch. 
The alveolar process, or 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 OF THE FACE AND JAWS. 
69 
.added 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 decline 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, or internal tubercle of the lower jaw, 
is just behind the symphysis, or on the 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 mylo 
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 
elongated. The dentes sapientise 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 co- 
ronoid process seems increased in length. 70 
OF THE TRUNK, 
HOLES.—The holes of the jaw are chiefly two: 
A large hole on 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 impression as deep as that of arteries in a bone, we 
find here two grooves, first, one marking the great nerve, as 
it advances towards 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 TIIE TRUNK; OR, OF TIIE 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 hone. This long line consists 
of twenty-four distinct bones, named vertebra?, 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 nerv- 
ous system. 
The vertebra are arranged according to the neck, back, and 
loins, and the number of pieces corresponds with the length 
of these divisions. The vertebra of the loins are five in 
number, very large and strong, and bearing the whole weight 
of the body. Their processes stand out very wide and free, 
not entangled with each other, and peforming the chief mo- 
tions of the trunk. The vertebra 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 sometimes chang- 
ed, according to the proportions of the body; for, where the 
loins are long, there are six vertebra of the loins, and but eleven 
in the back ; or the number of the pieces in the back is some- 
times 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 support- 
ing the weight, of the body, and hollow behind, for transmit- 
ting 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 pur- 
chase to those muscles which turn the spine ; and of one pro* 72 
OF THE TRUNK. 
cess, the spinous’process, which stands directly backwards from 
the middle of the bone ; and these processes being felt in di- 
stinct points all the way down the back, give the whole the 
appearance of a ridge ; whence it has the name of spine. 
The body 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 
spongy 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 j oined 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 
vertebrae of the back, where there is almost no motion and less 
weight; 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; andthey are united 
again by the articulating processes, which makes a very move- 
able joint of the common form. The articulating processes 
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 nanled 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 
from the middle of that arch, and opposite to the body, the 
spinous process projects. Now the spinous, and the trans- 
verse processes, 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 power- 
ful lever to work their effects by. The 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 turning the vertebrse, for there is no provision for much 
of a lateral motion in the lower part of the spine, but the 
muscles which are implanted into these, are more commonly 
used in assisting tfiose 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 re- 
present the general form of the vertebra, by describing one 
from the loins, because of the distinctness with which all its 
parts are marked. In the lumbar vertebnejrthe perpendicular 
height of the body is short, the interverteoral substance is 
thicker in the other parts of tha spine, and the several proces- 
ses stand off from each other distinct and clear; all which are 
provisions for a freer motion in the loins. The arch of the 
lumbar vertebra 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 vertebra; of 
’he loins present to the eye, looking from within the body, a 
T T 74 
OP THE TRUNK, 
large, thick, and massy column, fit for supporting so great a 
weight. 
The spinous process is short, big, and strong. It runs 
horizontally and directly backwards from the arch of the spi- 
nal 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 
secure 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 vertebra of the back.—The character of the 
vertebrae 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 vertebrae are still further abridged; and the further to 
sustain the column, there is a groove on the under surface of 
the spinous procffis, 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 vertebrae, 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 vertebrae are much curbed. And we also 
get another mark by which the dorsal vertebra maybe known, OF THE TRUNK. 
75 
viz. that each vertebra bears two impressions of the rib which 
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 
distinct projections, as they stand out so directly from the 
transverse 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 
sidt. 
The 12th, or lowest dorsal vertebra, has also the entire head 
of the rib impressed upon it, and it has no articulating sur- 
face on the extremity of the transverse process. 
Of the vertebra of the neck.—The vertebrae 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 hollow for receiving the intervertebral substance, but the 
surfaces of the body are flat or plain, and the articulating pro- 
cesses 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 proces- 
ses being also inclined backwards, the two surfaces are plain, 
opposed to each other, and the one prevents the vertebra: from 
sliding forwards, and the other prevents it from sliding back- 
wards, while a pretty free and general motion is allowed. The 
spinous processes of the neck are short and project directly 
backwards; they are for the insertion of many muscles, and 
therefore they are split. This bifurcation of the spinous pro- 
cess is not absolutely peculiar to the cervical vertebrx ; 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, be- 
cause there are few muscles attached to it; and the process of 
the last vertebra of the neck is not bifurcated, so that it ap- 
proaches to the nature of the dorsal vertebrx ; 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 prominens. 
The transverse processes of the neck are also bifurca- 
ted, because there are a great many small muscles inserted 
into them also. But the most curious peculiarity of the trans- 
verse processes is that each of them is perforated for the 76 
or THE TRUNK. 
transmission of the great artery, which is named vertebral 
artery, because it passes through these holes in the verte- 
brae, which form altogether a bony canal for the artery. This 
artery, which is defended 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 con- 
tinues to perform its office. 
So that the character of these cervical vertebrae 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 articulating processes oblique, with regard to their 
position, and almost plain on their surface, The spinous pro- 
cess, which is nearly wanting in the uppermost vertebrae, is 
short and forked in all the lower ones ; the transverse process 
also is forked ; and the transverse processes of all the verte- 
brae, 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 verte- 
brae 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 uppermost 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 verte- 
brae of the for its processes are scarcely distinguishable : 
it has no body, unless its own 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 the circle of the dentata. The body is entirely wanting; 
ip its place, the vertebra has a flat surface looking backwards, 
which is smooth and polished by the rolling of the tooth-like 
process; there is also a sharp point rising perpendicularly 
upwards towards 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 OF THE TRUNK, 
77 
extended betwixt them, called the transverse ligament, which, 
like a bridge, divides the ring into two openings; one the 
smaller, for lodging the tooth-like process, embracing it close- 
ly ; the greater opening is for the spinal marrow: the liga- 
ment confines the tooth-like process ; and when the ligament 
is burst by violence (as has happened,) the tooth-like process, 
broken loose, presses upon the spinal marrow; the head, no 
longer supported by it, falls forward, 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 has 
two smooth surfaces 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 upper 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 upwards; and the fore end of each 
oval is turned a little towards its fellow. Now, by the obli- 
quity of the condyles, and this obliquity of the sockets which 
receive them, all rotatory motion is prevented, and the head 
performs, by its articulations with the first vertebra or atlas, 
only the nodding motions; and when it rolls, it caries the 
first vertebra along with it, moving round the tooth-like pro- 
cess of the dentatus. The articulation with the head is a 
hinge joint, in the strictest sense : it allows of no other mo- 
tion than that backwards and forwards ; the nodding motions 
are performed by the head upon the atlas, the rotatory mo- 
tions are performed by the atlas moving along with the head, 
turning upon the tooth-like process of the dentatus. 
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 property 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 den- 
tatus by any hollow, but lies flat upon the surface of that bone. 
It is also 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 intervertebral substance; 
and since the atlas attached to the head moves along with it, 
turning as upon an axis, it must have no spinous process ; 78 
OP THE THUNK, 
for 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 but- 
ton where the spinous process should be, which, however, has 
a small notch on it. The transverse process is not fork- 
ed, but it is perforated with a large hole for the vertebral ar- 
tery ; 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 
impression of the artery, which makes the ring of the vertebra 
exceedingly thin. 
But the form of the dentatus best explains these peculiari- 
ties of the atlas, and this turning of the head. 
The DENTATA or AXIS is so named from its project- 
ing 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 spi- 
nous process is short, thick, and forked ; and that it is turn- 
ed much downwards, so as not to interfere, in any degree, 
with the rotation of the atlas. 4. That its tooth-like pro- 
cess, 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 without the help of ligaments, it is al- 
most 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 
a broad and flat articulating surface, one on either side.— 
These articulating surfaces are placed like shoulders ; and the 
atlas being threaded by the tooth-like process of the dentatus, 
is set 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 vertebrae 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 inter- 
stice of each vertebra ; so that there is no hole in the bone re- 
quired, but the nerve escapes by going under the articulating 
process. 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 last 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 cartilage, 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 which ever side we incline, and it 80 
OP 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- 
tebrae, 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 
performs 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 vertebra; 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 th OP 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 ribs.—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 vertebrae 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 
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 towards the lungs. But this flatness of the 
rib 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 82 
OF THE TRUNK. 
form which the thorax assumes in all its degrees of elevation; 
for when the rib rises, and during its rising through all the de- 
grees of elevation, it still keeps its flat 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 surgical 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; and that, if it 
be wounded, it will bleed largely from its nearness to the 
greatest artery of the body ; that it is easily shunned, by keep- 
ing 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 vertebrae; all the vertebrae 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 vertebrae, 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, 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. 
83 
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 tubercle, 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 intexxostal 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 ribs, 
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 j the lower opening so 
large, that 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 fiat 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 sternum ; 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 TRUNK. 
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 betwixt 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 ol the ribs complete the form of the thorax, 
and form all the lunated edge ol 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 their 
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, com- 
pletes the cavity of the chest; it is for completing 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 
r°H. 
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 dis- 
tinct 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 life, 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 
salient white lines which traverse the bone, mark where the 
intermediate 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 trian- 
gle, which is uppermost, towards the root of the 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 cartilage of the first rib ; and the second rib is implant- 
ed 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 receive 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 vertebrae 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 
OP THE TRUNK. 
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 c artilago mucronata, the point- 
ed cartilage, or cartilago ensiformis, or xipiioides, the 
sword-like cartilage. One half of the pit for the attachment of 
the seventh rib is on this portion. This cartilaginous point 
extending downwards over the belly, gives a sure origin and 
greater power to the muscles of the abdomen, and that with- 
out embarrassing 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 occasion 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 
unfrequently the most dreadful consequences ensue. I have 
already 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 bui-5t; but more commonly the 
patients die a slow and miserable death; for the inflammation, 
which begins in the place of the wound 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 assist- 
ed, 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 betwixf 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 cen- 
tre of all the great motions of the body, that when we believe 
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- 
eygis, is called the false spine, or the column of the false ver- 
tebra ; authors making this distinction, that the true verte- 
bra are those of the back, neck, and Idins, a column which 
grows gradually smaller upwards; the false vertebra 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 original- 
ly the form of distinct small vertebra. These distinctions are 
lost in the adult, or are recollected only by the marks of for- 
mer lines, for the original vertebra are now united into one 
large and firm bone, which is named the column of false ver- 
tebra ; because, having no motion, it wants the chief charac- 
ter and use of the true ones. 
W e can recognize the original vertebra, even in the adult 
bone, for we find it regularly perforated with holes, for the 
transmission of the spinal nerves ; we find these holes regu- 
larly disposed in pairs; we see a distinct white and rising line 
which crosses the bone, in the interstice of each of the ori- 
ginal vertebra, 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. 88 
OF THE TRTJKK. 
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 
surface is irregular and rough, with the spines of former ver- 
tebrae, giving rise to the great glutaei muscles, (which form 
the contour 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 
vertebrae 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 there- 
fore 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 shcrum, 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 
uses are not so distinctly known ; for the small nerve 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, is 
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 
sacrum 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 immovea- 
ble, 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, 
v/hich continue moveable upou each other, till manhood: then 
the separate bones gradually unite with each other, so as to 
form one conical bone, which bulgings and 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 processes; 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 90 
of The trunk. 
of os ilium, os ischium, and os pubis. The os ilium, the 
haunch-bone, 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 we 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 innominatum. It 
rises upwards from the pelvis in abroad expanded wing, 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 are 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, by 
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 are more distinct, and more important marks ; for 
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 vaginae 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 prfrt, and upon the inside 
there is a depression lodging the iliacus internus and psoas 
lhagnus. 
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 
which it is connected with the os sacrum at its side, the verv 
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 line a innominata, is seen 
upon the internal surface of the bone, dividing the ala, or wing, 
fromthatpart 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 
OF '1HE 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 j nearly one half.. 
From the body, a sharp pointed process named spinous pro- 
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 Ihe sacro-sciatic hole, and 
gives passage to muscles, and to the great nerve of the lower 
extremity, named the great sacro-sciatic nerve. 
The tuber, or round knob, being the point upon which we 
rest, this bone has been often named os sedentarium. 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 ol 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 flat, 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. 
93 
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 innominata 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 or crest of the pubis. This circle of the brim supports 94 
OF THE TRUNK, 
the impregnated womb, keeps it up against the pressure oi 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 bone 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 ; 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 strength ; the shoulders broad, the haun- 
ches 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 broad; 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. 
We know, from much experience, that where the pelvis is 
of the true size, we have an easy and natural labour: that 
where the pelvis is too large, there is pain and delay ; but not 
that 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 
“ was 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 alivays 
dissolved as a wise provision of nature for facilitating natural, 
and preventing lingering labour, compensating for the frequent 
deviations both 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 which 
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, per- 
haps 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 cartilage co- 
vers the end of each bone, and these are joined by a membra- 
nous or ligamentous substance : this ligamentous substance is 
the part 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 
u each otherthe 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 does perform its office so completely, that 
while it remains entire, though the bones shuffle sideways 
upon 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 wrillingly abide. 
Now, it is plain, that since a separation, amounting only to 
the 12th 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. I 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 
balanced 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 be 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 no longer be 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- 
union of the bones, the pelvis must be bound up with a circular 
bandage verv 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 bv walking about their room ? who often walk 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 Hunter. 
£ Denman says twenty-five or thirty vears. 
§ Spence’s caseR. 98 
BONES OF THE 
few days more? 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 ? 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, AND FOOT. 
I. 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 ol the thigh. This bending of the thigh- 
bone has been a subject of speculation abundantly ridiculous, 
viz. whether this be an accidental or a natural arch. There 
arc 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 curve 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 superaddecl, 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 unembarrassed 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,) Irom their office, 
which is the receiving those great muscles which not only 
bend and extend the thigh, but turn it upon its axis ; lor these 
processes are oblique, so as to bend and turn the thigh at 
once. 
The trochanter major, the outermost 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 ; 100 
BONES OF THE 
therefore the gfeat trochanter stands above the neck, and ts 
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 gemini, the obturator internus 
and externus. On the lower part there is a very strong mark- 
ed ridge, which is for the insertion of the gluteus maximus. 
The trochanter minor, or lesser trochanter, 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 obli quity of their in- 
sertion into it, turn the thigh, and bend it towards 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 fern oris 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 
thigh : 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. 
The 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 fiat 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 pf the thigh- THIGH, LEG, AND FOOT. 
101 
bone ; far the bones are separated at their heads, 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 hinders the motions of the thigh, and the head is 
formed 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 trochanters, 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 
shaft or body 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 true place, and so fixed that 
it cannot roll, we are assured that it is luxated ; but when the 
trochanter is upwards, with the thigh rolling freely, 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 
is 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, i'of 
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 fiat 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- 
ceiving the 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 bones 
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 lodgment of the muscles, which extend the foot, and 
bend the toes ; and the anterior and outer surface is hollowed 
by the lodgment 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 popliteous 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 inner 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 maleolus interims, 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 cancelii, or spongy substance within ; has pretty firm, 
plates without; is much strengthened by its ridges, and by its 
triangular form: its ridges are regular with regard to each 
other, but the whole bone is twisted as if it had been turned 104 
HONES 01' THE 
betwixt the hands when soft: this distortion makes the process' 
of the 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 ; the 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 a long slender bone, which is useful part- 
ly in strengthening the leg, but chiefly in forming the ankle- 
joint; for the tibia only is connected w'ith the knee, while the 
fibula, which has no place in the knee-joint, goes down below 
the 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 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 the insertion of the lateral 
ligament, and of the1 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 thongh the fibula 
is not i*eceived deep into the tibia, this ivant 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; but above all, by the ten- 
dons of the outer ham-sti’ings 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 cf the foot. THIG1I, LEG, AND FOOT. 
The extreme point of the 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 a 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, though 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, (?. e.) joined 
into one by disease. 
The fibula may be thus defined : it is a long 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 form of the leg when the tibia is 
carious or broken ; the fibula, though it has little connexion 
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 office of guarding the ankle, 
it is so true, that the ankle cannot yield till this guard of the 
fibula be broken. 
Rotula or patella, or knee-pan, is a small thick bone, of 
an oval, or rather triangular form. The basis of this rounded 
triangle is turned 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 anatomists 
of the first name, choose to speak of the patella as a mere 
105 106 
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; for 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 muffles 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 patella 
raises the mechanical power of the joint in exact proportion 
as the contraction 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 sin- 
gle 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 of- 
ten, by a sudden violent exertion, their power is so much in- 
creased, 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 cartilages are always lubricated, and the bones are 
never joined by anchylosis with each other; but the effect is 
rather a diffused elasticity than a marked and perceptible mo- 
tion in any one joint. THIGH, LEG, AM) FOOT. 
The seven bones of which the tarsus is composed are, 1. 
The astragalus, which 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 naviculare, 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 point 
of 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, (i. e.) betwixt the astra- 
galus, os calcis, and naviculare, 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, which being suited to this pulley of the 
astragalus, 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 
107 108 
OF THE B0NKS. 
shoulder-bone by which it is articulated with the scaphoid 
bone. 
POINTS OF DEMONSTRATION. 
1. Superior surface corresponding with the scaphoid cavity 
of the tibia. 2. Internal articulating surface for the maleolus 
interims. 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 w hich is like 
a continuation of this last, but which rests upon a cord or 
tendon which is stretched betwixt the os calcis and navicu- 
lare. 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 
projection backwards to which the tendo achilles is inserted. 
The lower and back part of the bone is rough but peculiar in 
its texture for the attachment of the cartilaginous and cellular 
substance on which it rests. We next notice an irregular ar- 
ticular surface, or rather two surfaces covered with cartilage, 
by which this bone is joined with the astragalus. Another 
articulating 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 
which 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 which stands internally, and 
gives attachment tothe ligamentum inter os calcem naviculare 
et astragalum. 
3. The next bone is named os naviculare, or os scaphoi- 
Des, from a fanciful resemblance to aboat. But this is a name 
of which anatomists have been peculiarly fond and which, 
they have used with very little discretion or reserve : the stu- 
dent will hardly find any such resemblance. That concave 
side which ..looks backw ards, is pretty deep, and receives the 
head of the astragalus : that flat 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 cuneiform 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; hut 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 cunei- 
form bones, is much smaller, and is therefore named os cu- 
neiform minimum. The third in order, of the cuneiform 
bones, is named os cuneiform medium.* 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 cuboides.—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. 
The 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 them 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 cuneiform 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 cuneiform bones that stand in the middle betwixt 
the other two. 110 
UOXES OF 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. 
The sesamoid 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 suffer 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 
pulleys, 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 
peromei tendons, which run uucler 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 
effect of friction. 
Metatarsus.—T]ie metatarsus, so named from its being 
placed upon the tarsus, consists of five bones, 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 terminate, 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 
degree of rotation than our dress allows 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 re- 
marked, that the nearer extremity of the metatarsal bone of THIGH, LEG, AND FOOT. 
111 
the little toe 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 other marks of the metatarsal bones are 
chiefly useful as directing us where to cut in amputating these 
bones; and the surgeon will save the patient much pain, and 
himself the shame of a slow and confused operation, by mark- 
ing 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 
articulating surface is marked by a ridge which corresponds 
with the interstice of the sesamoid bones. 
CHAP. VII. 
t 
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 
ligaments, nor any other form of connexion, but is parted 
from it by several layers of muscular flesh, so that it 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 
processes, 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 not 
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 be- 
ing able to recognize on the living body all the processes and 
projecting points. 
The flat side of the scapula is mooth, 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 mista- 
ken 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; 
the other musculus infra spinatus scapulae, as being below the 
spine. A third muscle is named subscapularis, as lying under 
the 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 vari- 
ous directions, and which impress the scapula with gentle 
risings and hollows on its upper as well as on its lower surface. 
The triangular form of the scapula must be next obser- 
ved. The upper line of the triangle is the shortest; it is named 
the costa or border. This superior costa of the scapula re- 
ceives those strong and flat muscles that raise the shoulder up- 
wards. 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, 
indeed, its ordinary movement. But it gives rise to two small- 
er muscles, which, from being a little rounded, are named the SHOULDER, ARM, AND HAND. 
113 
inusculi teretes, which round muscles being implanted into the 
arm-bone, pull it downwards. 
The long side of the scapula, which 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 litde 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 interior more acute. From the inferior angle the teres 
major takes its 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 any7 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 hone 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 (/. 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 no?; 114 
BONES or THE 
only from the back of the scapula, and from the sides of its 
spine, but also irom the inner surlace ol this tense membrane. 
The spine traverses the whole dorsum, or back of the scapula; 
it receives the trapezius muscle, that beautiful triangular mus- 
cle whic i 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 hign point is named the acromion process. It is the 
continuation and ending of the spine, which at first rises per- 
pendicularly trom 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 its If ; 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 joint, 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 
coracoid process. This also guards and strengthens the 
joint; though it cannot prevent luxations, it makes th* m 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, 
which 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. 
115 
and so eludes the force. Fal.s 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 fails ; it is lux- 
ated by a twisting of the arm, not by the force of a direct 
blow. 
The 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 connexion with the breast. 
The clavicle is placed at the root ot 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 
button-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 the capsule 
or purse; it is further provided with a small moveable carti- 
lage, which (like a friction-wheel in machinery) saves die parts, 
and facilitates the motion, and moves continualy 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 
th 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 acromion ; 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 
SONES OP THE 
on which fhe scapula moves and turns, being connected'with 
the trunk only by this single point, viz. the articulation of the 
clavicle with the breast-oonc. 
The os humeri is one of the truest of the cylindrical bones ; 
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 ; 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 w eak 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, v ithout 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 
Eesser tuberosity has 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 
with 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 
5n irregularity for the attachment of the deltoid muscle : and SHOULDER ARM AND HAND. 
117 
j3b 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 leading 
to either condyle, which it is of some consequence to observe ; 
for the elbow-joint is a mere hinge, the most strictly so ol any 
joint in the body: it has, of course, but two motions, viz. 
flexion and extension ; and it has two muscles chief!), one for 
-extending, the other for bending the arm : the flexor muscle 
lies on the forepart, and the extensor on the back part of the 
arm ; 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 be)ond the mere edges of the bone, there are 
two fasciae or tendinous webs which go off from either edge of 
the humeris, 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 
condyles. 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, but which have no connexion 
with the joint. The chief use of the condyles of the shoulder- 
bone 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 j 
while the muscles which extend, the fingers need no more 
power than just to antagonize or oppose the flexors ; their on- BONES OF THE 
118 
ly business being to unfold or open the hand, when we are t# 
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 tall naturally 
towards the face and breast, so that by being folded merely 
without any turning of the os humeri, the hands arc laid across. 
The articulating surface which 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 cartilaginous pulley of the 
humerus. 
Bdongingto 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 
horn-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. 
RADIUS AND ULNA. 
The radius and ulna are the two bones of the fore arm. 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 
sigmoid cavity of the ulna. But this sigmoid cavity were a SHOULDER, ARM, AND HAND. 
119 
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 
two curious purposes ; it serves as a long lever tor 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 corunoid process from its horn or 
pointed form ; it stands up perpendicularly from the upper or 
forepart of the bone; it forms the forepart of the sigmoid 
cavitv, and completes the hinge. On the root of thecoronoid 
process there is a rough tubercle for the attachment of the 
brachialis internes. 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 guards, 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 sigmoid cavity, for receiving the upper head of the 
radius. Betwixt these there is a pit for rect iving 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 interroseous ligament is stretched ; and 
this interroseous 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 lore arm together so 
strongly, that though the ulna belongs entirely to the elbow- 
joint, 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 anuconeus muscle. The ulna, bigger 120 
OF TI1E BOXES 
at the elbow, grows gradually smaller downwards, till it termi- 
nates almost in a point. It ends below in a small round hcad? 
which is named the lower head of 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 head of the ulna, like an axis or spoke. 
Below this little head, the bone ends towards the side of the 
little finger, 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 ligament which secures the wrist there. 
And as the styloid process and the olecranon, the two extn mi- 
ties of the ulna, are easily and distinctly felt, the length of this 
bone has been used as a measure, and so it was named cubitus 
by the ancients, and is named ulna by us. 
Radius.—The radius is the second bone of the fore arm, 
has its position exactly reversed with that of the ulna : for the 
ulna, belonging to the elbow, has its greater end upwards j the 
radius, belonging to the wrist, has its greater end downards; 
and while the ulna only bends the arm, the radius carries the 
wrist with a rotatory motion, and so entirely 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 is smaller; of a round, flat- 
tish, and button-iike shape, and lies so upon the lower end of 
the humerous, 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 flat 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. 
121 
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. 
Immediately under this neck, and just below the collar of 
the bone, their 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 
process of the radius. 
So the scaphoid cavity of the radius forms the joint with the 
wrist; but their 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 
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 way, 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, into 
a very narrow space, very firmly tied together, by cross liga- 122 
BONES OF THE 
ments, making a sort of ball or nuclseus, a solid foundation, 
or centre of the rest of the hand. 2. The metacarpus is for- 
med of five long bones, founded upon the carpal bones, and 
which, departing from that centre in somewhat of a radiated 
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 
nuclseus, firm, almost immoveable, and like the knave of a 
wheel j then the metacarpal bones founded upon this are pla- 
ced like the spokes or fellies of the wheel, and having a freer 
motion ; and, lastly, the fingers by the advantage of this radi- 
ated form, in the bones upon which they are placed move 
very nimbly, and have a rotatory as well as a hinge-like mo- 
tion ; 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 
observe 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 
outwards. On the internal surface, again, we find the num- 
ber 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 to- 
gether in a less regular form, crowded, and lapped over each 
other; but in this hollow, the four corner bones arc more re- 
markable, projecting towards the palm of the hand, so as to 
be named processes : and they do indeed perform the office of 
processes ; for there arises from the four corner points a 
strong cross ligament, 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 de- 
scription 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 connexion and place, and the particular uses of each 
bone; in reading of which, the student should continually re- SHOULDER, ARM, AND HAND. 
123 
turn to the plates, or he must have the bones always in his 
hand. 
1. ROW FORMING THE WRIST : viz. 
OS SCAl'HOIDES, I.UNAKE, CUNEIFORME, MAGNUM, 1’ISIFOHME. 
Os sc aphoides.—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 lunare is named from one of its sides being some- 
what of the shape of a half moon; it is next in size to the 
scaphoid bone, and is equal to it in importance; for they arc 
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 articula- 
tion with the os magnum. 
The os cuneiforme, or wedge-like 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 
the lunare and pisiform bones. 124 
BONES OF THE 
1. We may readily distinguish the surface articulated with 
the os Iunare. 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 pisiforme is a small, neat, and round bone, named 
sometimes orbicular, or round bone, but oftener pisiform, 
from its resemblance to a pea. It is placed upon the cuneiform 
bone, and it stands off 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 im- 
planted, and the flexor carpi radialis, one of the strong muscles 
for bending the wrist. 
2. ROW SUPPORTING THE METACARPAL BONES I viz. OS TRAPEZIUM? 
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 similunar surface which 
touches the convexity of the scaphoides, and another which 
articulates with the trapezoides. The fourth articulating sur- 
face of this bone is opposed to the head of the metacarpal 
bone of the finger. 
The trapezoides 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, bv two planes, to the metacarpal bone of SHOULDER, ARM, AND HAND. 
125 
the fore finger, on the radial surface to the tapezium, and on 
the ulner surface to the os magnum, having thus five planes 
or surfaces. v 
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 
circumstance 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 scaphoi- 
des ; on the radical surface the magnum is articulated with 
the trapezoides ; 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 
metacarpal 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 cuneiform of the first row. It 
is large and squared; but the thing chiefly remarkable is that 
process from which it takes it 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 they are joined to each 
other, are 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 scarcely liable to luxation; and al- 
though one only is called cuneiform, they are all somewhat 
of the wedge-like form, with their broader ends outwards, 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 
projecting upon the back of the hand, is the only form of lux- 
ation 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 heads are small and flat, and grouped 
very closely together, to meet the carpal bones. But they 126 
BONES 01' 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 general; 1. That their nearer 
heads, being flat and squared, gives them a firm implantation 
upon their centre or nuclseus, 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 the fingers, S. 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 
farther necessasy 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 
fingers, three joints. 
Thumb.—The first bone of the thumb resembles the meta- 
carpal bones in size and strength, but 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 finger-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; have no rolling; are as strictly hinge-joints as the 
knee is. 3. Here, as in other hinge-joints, the capsule is so 
particularly strong at the sides, as to be named lateral liga- 
ments. When these lateral ligament 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 fin- 
ger-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 affords 
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 sethiopica. 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 
crab and lobster. 
* By Charles Bell, OF THE TEETH. 
128 
The teeth differ 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 inquiry 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 tang 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 
mark. 
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 sometimes see in the human teeth. See specimens in mv 
Collection. OF THE TEETH. 
129 
whole length of the j aw, and they are provided with a continual 
growth from behind, which pushes the tooth out itv 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 tine and sharp. 
The cuspidati, or canine teeth, are next in order, 
counting backwards. They are two in number in each jaw. 
T hey have a general resemblance to the incisor teeth, for when 
their points are worn oil', 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 ol 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. 
T he 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 bar- 
biroassa, 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. rihe 
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 
sometimes there are distinctly two fangs; their roots are 
oftener curved than those of the other teeth. The second bic- 
uspis 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 crown ; for although there are only, two or three 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 19 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. 
OF 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 incisores, four in each jaw ; the 
cuspid ati, two in each jaw; and the mol ares, four in num- 
ber 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 incisores of 
the lower jaw; then the lateral incisores of the upper jaw, 
though sometimes the lateral incisores of the upper jaw ap- 
pear before those of the lower jaw. The 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 lower 
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 
molares of the adult are properly the permanent teeth (immu- 
tabides,) for they alone arise in this part of the jaw, and 
remain in their original places ; yet we must recollect that, in 
opposition 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 
state of nature, and a thousand circumstances have secretly 
affected 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 incisores 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 two 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 
cuspidati retaining their hold some time longer. 
The anterior molaris and the cuspidati falling, are succeeded 
about the ninth year by the second of the hicuspides 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 requires its full proportion about the age of eighteen 
or twenty, when the third molaris, or the dens sapientice, makes 
its appearance. This tooth is shorter and smaller, and is in- 
clined 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 shor- 
ter, 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 
OF TIIE 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 crow n, 
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 was 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 de- 
struction of the soft parts, the teeth drop from the skull.— 
There is betwixt the tooth and its socket in the jaw a common 
periosteum. 
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 animal 
production with a vitreous substance, although the enamel very 
widely differs 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 
enamel are nearly the same with those of bone. In hone the 
phosphate of lime is deposited on the membranes, or carti- 
lage* hut 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 control 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 
fluat of lime, to which ingredient these chemists attribute the 
hardness of this crust.f 
* In brutes there is a considerable variety in the relative form of the enamel and 
hone of the tooth. 
+ Iiy Mr. Hatchetts’s Experiments, (Philos. Transact. 1799,) we learn that bone 
consists of phosphate of lime, with a small proportion of carbonate of lime. The OF THE TEETH. 
133 
Although w6 call the earthy deposite, the hardening matter, 
Vet 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 : hut 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 pe- 
netration 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 enamal is not tinged, we have 
a convincing proof that the vascular system has no operation, 
on the enamel after it is formed. 
In 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 cloven-hoofed animals are cover- 
ed with a black vitreous matter, ancl 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 enamal, we must be aware of 
the had effect of acidulated washes and powders 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 
constitution of the part to restore. 
The chemical composition, and the manner of combination 
shell of the crab and lobster consists of phosphate of lime and carbonate of lime, the 
latter being in the greatest quantity- The testaceous shells consist entirely of carbon- 
ate oHime. The matter of bone and teeth consists of phosphate of lime and a sma 1 
portion of carbonate deposited in the interstice of an animal substance which is ot 
the nature of cartilage, and proves to he gelatine. The bones of fish differ from 
those of and brutes, in the larger proportion of animal substance. These 
chemical facts are, however, of little import to the anatomist : he is desirous of 
knowing what property of life these parts are endowed with : whether they are 
formed by a final depositation, or are still under the influence of the circulating 
vessels, whether they possess a principle of self-preservation independent of vas- 
cularity, or are like common dead matter altogether out of the system. 
The formation of hone has heen very fully described. The formation of shell 
is more like that of teeth. The testaceous shell consists of layers; the layers are 
formed successively by secretion from the animal body, and each successive layer 
is broader than the preceding, answering to the increased circumference of the ani- 
mal Reaumeur broke the shell of a snail, and he found that when he covered the 
surface of the creature and prevented the exudation, no shell was formed. There 
has been a question agitated regarding the posihility of nutrition, without the in- 
tervention of vessels, which bears upon this subject, of the nature of shell and teeth. 
OF THE CENTRAL EONY PART OF THE TOOTH. 134 
OP THE TEETH. 
of the matter forming the central part of the tooth, and of the 
fangs, 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 ot giving passage 
to vessels, we conclude that it is not vascular, and are apt to 
suppose that it holds its connexion 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 ot 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 fur- 
ther 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 un- 
dergoes the same changes by absorption which the other bones 
are proved 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 expe- 
riment 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 vascu- 
larity ; 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 absorb- 
ed, so as to drop out without the mechanical pressure ot the 
permanent teeth, and before they have advanced to be in con- 
tact with the former. 
The teeth seem acutely sensible ; but a little consideration 
teaches us that the hard substance of the teeth is not endowed OF THE TEETH. 
135 
\vith sensibility, and that it must be the remains of the vascu- 
lar puip, presently to be describee, occupying the centre of the 
tootn, which being supplied with nerves, gives the acute pain 
in tooth-ache. It is a medium communicating or abstracting 
heat, that the tooth itself gi'v s pain. When wrought upon 
by the dentist, no sensacion is produced unless the tremor be 
communicated to the centre, or unless tiie abrading, or cutting 
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, taken 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, the 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-ach 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 cir- 
cumstances which will make us conclude that there is no vas- 
cular action in the teeth, and incline us to believe that they 
possess a low degree of life, independent of vascular action. 
Supposing the bony part of the tooth to bevascular, and to pos- 
sess the principle 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 common effects of excitement and ex- 
foliation, or inflammation in the latter ? 
In rickets, and molities ossium, and other diseases of debi- 
lity 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 bony system under these 136 
OF THE TEETH. 
diseases, are produced by the activity of the absorbent prevail- 
ing 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 matter which is not re-absorbed, nor subject to the 
revolution of deposition and re-absorption, which takes place 
in otiier parts of the body. Accordingly, we find in rickets, 
where the hardest bone yields, where the jaw-bone itself is 
distorted or altered in its form, that the teeth remain distin- 
guished for their size and beauty. In molities ossium, I have 
found 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 protuberance 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 defi- 
cient 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 ol 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 
accommodated. The teeth of the rodentia are wasted by at- 
trition 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 enveloped 
the ball alter 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 roots, is produced by an original defect in the formation. 
The filling'up of the cavity of the tooth is caused in the same 
* Se e the ingenious Inaugural Dissertation of Dr. Blake. OF 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 it 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 substance 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, &c.; but this happens in 
consequence of the central nerve being bmised 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 connexion 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 they are diseased. The only means of ope- 
rating upon the general state of the teeth is through the gums ; 
* See Herissant. 138 
and by keeping them in a state of healthy action, by the brush 
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 
painlui. If a healthy tooth be implanted in the jaw, the gum 
grows up around it, and adheres 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 it 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 to 
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. OF THE TEETH. 
139 
aiel is yet formed. Upon raising the shell of bone, which is 
of 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 iormed ; and a further observation will lead 
us to conclude, that this bony part ot 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 ot this pulp were successively ossified. 
If we now turn 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 ot the tooth. 
Gradually, and bv 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 coquc, or le germc de la dent, by the French authors, 
f This outer sac lias been called chorion, from the numerous vessels distributed 
i*pon it. See Herissant. 140 
OF 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 connexion with the circle of the crown of the 
tooth, rises up in connexion 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 
gratnenivorous animals. 
Mr. Corse, in a curious paper in the Philosophical Transac- 
tions of London for the year 1FO?, describes the grinding 
tooth of an elephant in the following terms : In describing the 
structure of the grinders, it must be observed, that a grinder 
is composed of several distinct laminae or teeth, each covered 
with its proper enamel; and that these teeth are merely joined 
to each other by an intermediate softer substance, acting likq, 
pement. 
* Ressembje assez a une petite bonrsa feme?. OF THE TEETH. 
141 
The structure of the grinders, even from the first glance, 
piust appear very curious, being composed of a number of 
perpendicular laminse, 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. 
1 he pulp of gramenivorous animals is not shaped like that 
which forms the human tooth ; it consists of several processes 
united at their base. The cc.psule 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- 
sufe, 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 
crusta 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 gremeni- 
vorous animals. The grinding teeth of the purely carnivorous 
animals, as of the lion and tiger, close like the blades of scis- 
sors : 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 TEJETH, 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 
inaugral Dissertation. 142 
OF THE TEETH. 
the jaws of a child, are destined to be shed, and to give placin- 
to the adult, or permanent set of teeth. Accordingly in ob- 
serving the progress of the formation of the first teeth, the 
rudiments of the second may also be seen in the foetus 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 connexion 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, lor the change on the deciduous and 
the growingteeth seems to be influenced bylaws 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 satisfactory 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 THE 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, their 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 nut rise, the first 
■ will remain, their roots unvvasted 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; but 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-bone, and what is more curious, their alveoli 
are distinct; for as the roots of the first teeth decay, their alveo- 
lar processes are absorbed, while again, as the 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, 
notwithstanding the bony 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 of the 
adjoining teeth. 144 
OF THE TEE TH. 
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 a speci- 
men of this in my collection, where the whole circle of the al- 
veolar processes and teeth is thrown off. This ha; pened 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 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 ir. 
OF THE MUSCLES. 
CHAP. I. 
MUSCLES OF THE FACE, EYE, AND EAR. 
I. MUSCLES OF THE FACE, 
rgi 
-3- HE occipito frontalis is a broad and thin n,oscular ex- 
pansion, 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- 
beliied 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, occipito-frontalis, sometimes epicranius, some- 
times BIVENTER or DIGASTRICUS CAPITIS. 
Origin.—The occipital portion is the fixed point of this 
muscle arising from the superior transverse 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 fix!ed more into the skin and eye-brows than into 
the bone : it is slightly attached to the bone, near the inner 
endof the orbitary ridge, and especially about the inner corner 
of the eye, and the root of the nose, by a smaller and acute 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; 
but its outer surface is so firmly 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. 
1 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 the 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 qye-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 alse que nasi, that there is 
some difficulty in dividing them. 
II. The corrugator 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 muscle ; it is firmer and smoother in its fibres. FACE, EYE, AND EAK, 
147 
greater muscles this little one might be most properly referred. 
So this slip of oblique fibres, rising from the inner anlge of the 
«ye, 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- 
Uugator 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 thin 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. Our name expresses the common opin- 
ion, 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 palpebra; 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- 
allv broader as it go£s over the eye-ball; it ends in the eye- 148 
MUSCLES OF 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 ol 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- 
pebrte, and their not being able to describe any muscle by 
which the upper eye-lid could be 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 palpebrae 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 dotvn the 
lower eye-lid, or whether some straggling fibres, 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 lowrer eye-lid is. 
almost immoveable, at least in man. 
MUSCLES OF THE NOSE AND MOUTH. 
V. Levator labii superioris and aljE 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 fasciculus 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 alas nasi: it raises the upper lip, and spreads the nostrils 
wide, as is observed in a paroxysm of rage, or in asthmatics* 
VI. The levator labii superioris proprius is distin- 
guished 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 the edge of the FACE, EYE, AND EAR. 
149 
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 l abiorum, because it operates equally on both lips. 
It is named caninis ; 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 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 arises 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 he 
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. Fcr this large flat muscle, which forms, 
in a manner, the walls of the cheek, arises chiefly from the 
coronoid process of the lower jaw-bone and partly also from 
the end ot 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 
* The filtrum is the superficial gutter along the upper lip from the partition of 
the nose to the tip of the lip. 150 
MUSCLES OF 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 intru- 
ments, it both receives and expels the wind : it dilates like a 
bag, so 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. Depressor 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, &c. the zygomatics and levators 
pull the angles of the mouth upwards. In fear, hatred, re- 
venge, contempt, and the angry passions, the triangulares, pull 
the corners of the mouth downwards ; and at the place where 
these met t, 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 depressor labii inferioris 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 orv the lower lip, as FACE, EVE, AND EAK. 
151 
on the upper one. It mixes its fibres with the orbicularis, and 
its use is to pull the lip downwards ; each muscle is of a square 
form, and thence has been often named quadratus the 
square muscle of the chin. 
XIII. The orbicularis 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 n asalis labii superio- 
rs 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 mouth. This phenome- 152 
MUSCLES OF THE 
non of the orbicularis muscle, dilating to such a wideness and 
in an instant closing the mouth again, with such perfect accura- 
cy, as to retain the breath, puts to naught all the vain calcula- 
tions about the contraction pf 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 fails 
into palsy, the muscles of one cheek cease to act; the mus- 
cles of the other cheek continue to act with their usual degree 
of power. This contraction of the muscles of one cheek ex- 
cites also the orbicularis oris to act, and so the 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— 
XVI. The DEPRESSOR LABII SUPERIORIS and ALiE NASI, 
which is very small, and lies concealed under the other mus- 
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 j course, the upper 
lip down, and is named, by Albinus, depressor alae nisi. 
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 j for one arises 
from the wing of the nose on each side, and meets its fellow 
in the middle ridge, where both are fixed into the middle car- 
tilage, or into the lower point of the nasil 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, he considered it as a 
fiction, having sought for it very carefully, but in vain. 
And XVI. The levator menti, which arises from the lowrer 
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 inferioris. 
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 ol 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*. 
153 
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, u that in 
one thing, he surely belonged to the long ear’d tribe;” upon 
which he moved his ears very rapidly backwards and for- 
wards.* 
XVII. Superior aukis 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, lrom the 
expanded tendon of the occipito frontalis, and is inserted into 
the back part of the antihelix. 
XVIII. Anterior auris is a very delicate, thin, and narrow 
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 auris 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 ;jr 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 cartilage 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 
muscular 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 heliois major lies upon the upper, or 
sharp point of the helix or outward ring; rising from the 
* Vide Palfin, who was his pupil. The celebrated Albinus could move his ears, 
f Fibre earnefe transverse, a nobis descripte. Valsalva, 154 
MljSCjL.ES OF THE 
upper and acute point of the helix, and inserted into the same 
cartilage a little above the tragus. 
XXI. Helicis minor rises lower than the former, upon the 
forepart of the helix, and runs across the notch which 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 antitragious lies on 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 TKANSVERSUS AURIS 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. 
TIie eye-ball is entirely surrounded by muscles, which turn 
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 
vises, 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 
tfheir only variety is that difference of place, which is expres- PACE, EYE, AMD EAR. 
155 
sed by the name of each. They all agree in these chief cir- 
cumstances, 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 either side, they completely 
surround the 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 the 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 the circle of the lucid 
cornea or window ; and their white and shining tendons form 
that enamelled-like part, which lies without the coloured cir- 
cle, and which is named the white of the eye, or the tunica 
albuginea, as if it were absolutely a distinct coat. 
Now, the only difference in these straight muscles is in re- 
spect to length ; for the optic nerve enters the eye, not regu- 
larly in the centre, but a little towards the inner side, so that 
the 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, the LEVATOR OC- 
uli or superbus, as expressive of haughtiness and pride. 
XXVI. And the rectus inferior, which is directly op- 
posite to it, is named deprimens oculi or humilis, as ex- 
pressing modesty and submission. 
XXVII. The rectus internus is called adducens, as 
carying the eye towards the nose, or bibitorius, because it 
directs 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 indignabundus, expresing anger or scorn. Such is the ef- 
fect 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 the eye is 
immoveably fixed. So that sometimes in our operations, 
when the couching needle approaches the eye fear comes up- 
on the patient, and the eye is fixed by a convulsive action, more 
firmly than it could be by the instruments, or by the fingers ; 
so that the speculum oculi is after such an accident of no use. 
The eye continues fixed during all the opperation, but it is 
fixed in a most dangerous way by a power which we cannot 
control, and which sometimes, when our operation is for ex- 
tracting one of the humours only, squeezes out the whole. 156 
MUSCLES OF THE 
XXIX. The obliquus superior arises along with the recti 
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 
superciliary 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 
upper 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 tfte 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 flat 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 rec- 
tus, and the entrance of the optic nerve. 
XXX. The obliquus inferior is, with equal propriety, 
named the musculus brevissimus oculi. It is directly opposite 
to the obliquus superior, in form, place, office, &c.; 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 in- 
serted broad and flat into the ball, exactly opposite to the in- 
sertion of the obliquus superior muscle. 
These two muscles roll the eye, whence they are named 
musculi circumagentes, or amatorii. But they have still ano- 
ther important office, viz. supporting the eye-ball, for the ope- 
ration 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 eye7ball turns under the operation of the recti muscles. 
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 upper 
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 successive 
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 down- 
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 litde 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 
pyramidal, its rays converging towards the jugum ; its mus- 
cular fibres are intermixed with strong tendinous ones; it is 
particularly 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 coron- 
oid process 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 158 
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 
branch of the lower jaw quite down to its angle. It is par- 
ticularly strong, has many massy bundles of flesh, interspersed 
with tendinous strings ; the parotid gland lies on its upper 
part, and the duct of the gland (as it crosses the cheek) lies 
over the 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 masseter 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 
pterygoideus internus is that one which rises from the inter- 
nal 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. The pterygoideus 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 pterygoideus minor. 
The jaw is moved chiefly by these muscles; the temporalis 
acting upon the coronoid process like a lever, the masseter 
acting upon the angle, and before it, and the pterygoideus in- 
ternus balancing it within, like an internal masseter 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 within outwards, pulls 
the jaw from side to side, and performs the motion of grind- 
ing. 
MUSCLES OF 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 ot 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 tem- 
poral bone. And, lastly, it has small cartilaginous pieces or 
joinings, 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 joiningof the horns to the body, and these are named 
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 wdndpipe 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 mo- 
tions. 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 down- 
wards ; others come obliquely from the coracoid process of 
the scapula, to move the throat backwards, while the os hyoi- 
des 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 which 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 THE 
the surrounding parts, serving as a fulcrum for them in the 
motions of the jaw, tongue, and gullet. Its cartilages are first, 
the scutiform or thyroid cartilage, which is named from its 
resemblance 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 
pomu.n 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 wind-pipe. xYnd upon its back, or deeper part, are seated 
those two small cartilages, which, with their ligaments, form 
the opening of the breath. 
The'arytenoid cartilages are two small triangular bodies 
seated within the protection of the thyroid cartilage. They 
are foclisbjy described with cornua ridges and surfaces, when 
they are so small that nothing further can be observed of their 
forms, than that 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 basin, whence their names. And these cartilages 
being covered with the common n embrane of the throat, 
which 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 betwixt 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 pro- 
portioned degree. 
The epiglottis is a fifth cartilage of the trachea, belonging' 
to it both by connexion 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 ol the tongue, and 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 sufficient 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 cricoid 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 OF THE THROAT. 
By this arrangement, I mean to include under one class, all 
those muscles which move the os hyoides, or the larynx, and 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 sterno-hyoideus, 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 sterno-tiiyroideus, which 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-hyoideus muscle. It arises under 
the sterno-hyoideus 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 immediate- 
ly covers 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 horn goes off from the body of the bone. 
These three muscles pull down the throat. The sterno-hy- 
oides, and stemo-thyroideus puil 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 saxne time a little down to the back. 
The muscles which move the throat upward are: 
XXXVII. The mylo-hyoideus. a flat and broad muscle, 
which arises from the whole semi-circle of the lower jaw, (i. e.) 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 symphvsis 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 hyoideus forwards and upwards 
when the jaw is fixed ; but when the os hyoideus is fixed by 
the muscles coming from the sternum, these muscles of the os 
hyoides pull down the jaw. 
XXXIX. The stylo-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 Innis, stylo-hyoideus alter ; but it 
is not regular, nor has it ever been acknowledged as a distinct 
muscle. 
XL. The digastricus or BIVENTER MAXILLjE inferioris 
muscle, is named from its having two bellies. One belly arises 
from a rugged notch along the root of the mastoid orocess, 
where the flesh is thick and strong ; going obliquely forwards 164 
MUSCLES OF THE 
and downwards, it forms a long 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 hyoideus 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 leel 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 connexion 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 niany of them very minute. 
XLI. The hyo-thyroideus 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- crico thyroideus is a very short muscle, 
passing from the upper edge of the cricoid to the lower mar- 
gin of the thyroid cartilage, chiefly at its side, and partly at- 
tached to its lower horn, which comes down 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 whith the voice chiefly de- 
pends are those of the rima glottidis; for there are many 
small muscles which have their attachment to the arytenoid 
cartilages, and which by their operation on the thyro-arvte- 
noid ligament govern the rima glottidis. XLIII. The musculus arytenoideus 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. Arytenoideus obliquus 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 rima : 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 arytenoftl cartilages directly back wards, 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. 
XLVI. The crico-arytenoideus OBLiquus is one which 
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 their 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.* 
LOWER JAW, THROAT AND TONGUE. 
165 
* There is in Albinus, a second set of fibres, which he calls thyreo arytenoi- 
deus alter, arising from the inner and upper part of the thyroid cartilage and in- 
serted into the arytenoid cartilage just above the insertion of the crico-arytenoi- 
deus obliquus; this muscle must have much the same action as the other. 
There is another muscle which has been omitted in the text, thyreo epiglotti- 
deus. 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 Albinus into 
*»ajor and minor, but this we cannot expect to find always, as it is onlv in verv 
'muscular bodies that we see fibres running from the thyroid Cartilage to the epig- 166 
MUSCLES OF THE 
These are all the muscles which belong to the larynx; and its' 
our arrangement the muscles of the palate and pharynx 
come next in order. 
When a morsel is to be thrown down into the (esophagus, 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. 
XLVTII. The AzYGosuvuLiE.—The velum pendulum pa- 
lati 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 uvulae, 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 molis arises from the point of the 
os petrosum, and from the Eustachian tube, and also from 
the sphenoid bone.* These parts hang oyer 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 to 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,! and the constrictor isthmi 
faucium, have a very different use. The circumflexus palati 
is named from its fibres passing over, or rather undeirthe hook 
of the internal pterygoid process; the muscle arises along with 
the levator palati, (z. e.) from the sphenoid bone at its spi- 
nous process ; and from the beginning of the Eustachian tube, 
lottis. Along with this muscle may be classed the set of fibres which are seen 
sometimes running from the arytenoid cartilage to the epiglottis, and called arv= 
teno epigloltideus. 
* From the Eustachian tube, it was named salpingo staphilinus ; 
from the sphenoid bone, spheno stapiitlinus ; from the pterygoid process, 
pterygo staphilinus ; from the petrous process it was named petro sal- 
pingo staphilinus ; as if there were no science but where there were hard 
names, and as if the chief mark of genius were enriching the hardest names 
with all possible combinations and contortions of them. 
f This also, has got a tolerable assortment of hard names, as circumflex- 
US PALATI, tensor palati, pat.ato salpingeus stapheltnus, externusa spue- 
STO-&AI?IJfGO-STAPHYLINUS, MUSCULUS TUB AE, Viz. EUSTACHIANAK SONUS 
PtERYGp-STAPHILINUS of CoWpef, 8cC, 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 
hook of the internal pterygoid process, and mounts again to 
the side of the velum. 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 clown the palate, and stretches it, and 
thence is very commonly named the tensor palati mollis, 
or stretcher of the palate.* 
LI. The constrictor isthmi eaucium 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.j This semi-circle 
forms that first arch which presents itself, upon looking into the 
mouth. 
LII. The 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 pharynx, 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, 
in the back parts of either jaw-bone. The oesophagus again 
is the tube which conveys the food down into the stomach, 
and this bag of the pharynx is the expanded or trumpet-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 staphilinus, from its origin in the tongue, and insertion into 
the uvutA. 
+ The salpingo phartngeus of Albinus, is no more than that part of the pala- 
to-pharyngeus which arises from the mouth of the Eustachian tube; 
§ In its passage down, its fibres are mixed with the stylo-pharyngeus, and in it? 
insertion they are mingled w ith the inferior constrictors, MUSCLES OF THE 
168 
smooth along the bodies of the vertebrae; before, it is protect- 
ed, and in some degree surrounded by the great cartilages of 
the larynx; the horns of the os hyoides embrace its sides, and 
it is covered with flat muscular fibres, which, arising from the 
os hyoides and cartilages of the throat, go round the pharynx 
in fair and regular orders, and are named its constrictors, be- 
cause 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 ; it 
expands fleshy upon the side of the pharynx ; extends so far 
as to take a hold upon the edge of the thyroid 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.:]: 
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.^ 
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 (z. 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 
hasbeen named cepualo-fharyngeus, fterygo-piiaryngeus, mye<x fharyngf.us, 
GEOSSO-PHAHTITGEUS. 
f This one is named hyopharyxgkits, or sykdksmo pharyxgecs, from its 
origin in the cartilage also of the os hyoides. 
+ This, of course, is named thyeiki-puauyxgkcs, and cmco pharyngecs. 
4 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 ; u 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. 
LYT. I'he constrictor inferior arises partly from the 
thyroid and partly from tfu cricoid cartilage ; and it again goes 
also obliquely, so as to overlap or cover the lower part of the 
constrictor meclius. This, like the other two constrictors, 
meets its fellow in a tendinous middle line ; and so the morsel 
admitted into the pharynx 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. 
LVI1. The cksophagus 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 gul^e. 
MUSCLES OF THE TONGUE. 
The muscles of the tongue are large bundles of flesh which 
come from the os hyoides, the chin, and the stylo process. 
Their thickness constitutes the chief bulk of the tongue. Their 
actions perform all its motions. 
L1X. The hyoglossus is a comprehensive name for all 
those which arise from the os hyoides. The muscles from the 
os hyoides go off 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 ol the ho ly and horn was called 
chondroglossus j 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- 
GLOSSUS. 
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. 
LX. The genio hyoglossus arises from the rough tubercle 
behind the symphasis of the chin. It has a very narrow or 
pointed origin ; it spreads out fan-like, as it goes towards the 170 
MUSCLES OF 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 sub- 
stance 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 hyoglossus, and as it is in the centre, 
and unconnected with any bone, it is named lingualis, as aris- 
ing in the tongue itself. 
The geneo hyoglossi muscles form 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, for 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- 
hyoidsei, 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-hyoidaei 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. 171 
CHAP. III. 
OF THE MUSCLES OF THE ARM* 
INCLUDING THE MUSCLES OF THE SCAPULA, ARM* 
FORE-ARM, AND HAND. 
The great peculiarity of the arm is, the manner of its con- 
nexion 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 easily 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 extention. 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 shoulde-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 
MUSCLES OF THE SCAPULA. 172 
MtrsCLES OF THE ARM, &C. 
beautiful muscles in the bod)' j and the muscles together 
cover all the shoulders and neck, with a lozcngc-like form, 
with neat and sharp points, extending txom the tip 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 nuchae. 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, 
downwards ; 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 the 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 effects, 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 par,t 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 occasionally a muscle of the head, pulling the 
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 must be reckoned 
different portions of the same. 
LXIII. Levator scapulae, named also levator p oprius 
ANGULARis, 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 bv a flat thin tendon to 
the upper corner of the scapula, to pull it upwards, as in shrug- 
ging the shoulders ; whence it is named musculus patieStijE. 
LXIV. and LXV. The rhomboid muscle stretches fl t, 
neat, and of a square form betwixt the spine nd the whole 
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 OF THE AKM, &c. 
173 
base of the scapula higher than the rising of the spine of the 
scapula; 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 vertebrae 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. 
JLXVI. 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 serrse, from their 
resembling the teeth of a saw ; and every muscle arising from 
the ribs must be a serrated muscle. The 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 s;des 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 takes also a* 
origin from, the 7th eervical vertebra;: it is so expressed in Albinas, 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. Wh n only the lower portions act, 
it pulls the lower angles 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, 
the tip of the shoulder is fixed and pulled downwards towards 
the chest, and the lower corner of the scapula rolls back- 
wards. 
LXVII. The pectoralis minor lies under the pectoralis 
major, 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 
clavicle, quite out to where it is joined to the acromion pro- 
cess : its chief use (since the rib is immoveable) must surely 
be to pull the clavicle, and consequently the shoulder down- 
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, &c.; 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 
rib 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 ; 
downvvards 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 MUSCLES OF THE ARM, 8tc. 
175 
trapezius, and assisted by ihc subciavius; and directly for 
wards by the pectoiahs minor. 
MUSCLES OF THE ARM; 
VIZ. THOSE MOVIKG THE OS HUMERI, OR ARM-BOKE. 
LXIX. The pectoralis 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 irom the sternum, it is tendinous, and the fibres 
from the opposite muscles cross and mix, so as to make a sort 
of fascia covering tbe bone. It is fleshy where it arises trom 
the ribs, and there it mixes with the external abdominal mus- 
cle. The fibres approach each other till they form a flat ter - 
don about an inch in breadth : and as the fibres approach ea..H 
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 cail 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 distinct- 
ion ; and they are sometimes described as two parts; it is 
those two bundles chiefly which cross each 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 fans, and which is in some degree the root of other 
muscles, especially of the longissimus dorsi. This broad sil- 
very tendon brgins 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 humerus ; they have been remarked, in the Windmill Sti’eet dissecting- 
room, more frequently in Lascars and Negroes than in Europeans. In Decem- 
ber 1.814. a body was dissected, in which there was found on both sides a slip of 
fibres 18 inches long, extending from the 4th and 5th rib to the fascia, between 
the triceps and brachialis internus, and a distinct slip of tendon might be traced 
even to the inner condyle. 
f Haller tells us, that when, at any time, he had rheumatism in this muscle, 
his breathing was checked ; and when he had difficult breathing, he found great 
relief by fixing the hands, raising the shoulders, and acting with the pectoral mus. 
oles It seems confirmed by these facts, that asthmatics take this posture ; women 
sn labour fix their arms, by resting upon the arms of their chair; those who play 
an wind instruments raise their shoulders in straining. 176 
MUSCLES OF THE ARM, kc. 
of the back of the sacrum, and from the back part of the cir* 
ele 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 tne side of the body, and as it lies over tne 
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 lace 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 musculus 
scalptor ani, or tensor 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 is pressed 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 MUSCLES OF THE AEM, See. 
177 
the shoulder-bone ; it arises from all that part of the clavicle, 
which is not occupied by the pectoralis muscle, and is separa- 
ted from it only by a fatty line ; it arises again in another bun- 
dle, Irom the point of the acromion process, and this middle 
bundle is also insulated by a fatty tine 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 fasci, which covers the infra spinatus 
muscle. And thus the muscle has three converging heads, 
viz. a head from the outer end of the clavicle, a head from the 
acromion, or tip of the shoulder, a head from the ridge of the 
spine, each divided froth the other by a fat line.* These heads 
or bundles of fibres, meeting about one-thircl down the hume- 
rus, form a short, flat, and strong tendon, which grasps or al- 
most 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, 
begin to help : nay, when the arm is raised to a certain point, 
more power still is required, and the clavicular part of the 
pectoral 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 late- 
ral portions, than raised by the middle one. 
LXX1I. Coraco brachialis.—The coraco brachialis, so 
named from its origin and insertion, is a long and rather slen- 
der 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 descends; 
it is all fleshy, and is inserted by a very short tendon into 
the os humeri, nearly about its middle, betwixt the brachialis 
and the third head of the triceps. It is perforated by the 
external cutaneous nerve. This was observed by Casse- 
rius, an Italian anatomist; and the muscle is often named 
MUSCULUS PERFORATUS CASSERII. 
* Albinas has distinguished it into seven fasciculi or bundles ; a very superflu1* 
ous accuracy. 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. 
LXXIII. The supra spinatus is so named from its oc- 
cupying the hollow of the scapula above the spine. 
It arises from the hack 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. 
4 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 deltoides, lies in the same di- 
rection 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 lar- 
ger 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 is very 
thick and strong, almost filling up the triangular cavity, and 
it is closed in like the former, by a strong tendinous expan- 
sion ; 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 liga- 
ment, is inserted into the middle of the same tuberosity 
with the former, and has exactly the same uses, viz. prevent- 
ing 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 of MUSCLES OF THE ARM, &c. 
179 
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 . Th* tere • minoh is a third muscle which co-ope- 
ratcs 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 early 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 it is very distinct in its tendon. The 
supra spinatus, infra spinatus, and teres minor, raise the arm. 
LXXVI. The teres 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 with it, and may be consi- 
dered as the congenor of the latisimus dorsi; and the two 
tendons are enclosed in one common capsule, or sheath of cel- 
lular 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 radiated or fan-like ; it 
is very fleshy, thick, and strong; the radii are each minutely 
described bv Albinus ; but Sabattier says, with good sense, 
that he cannot distinguish them, so as to describe them accu- 
rately ; and he might have added,that there was not the shadow 180 
MUSCLES or THE ARM, kc. 
of a motive for wasting time in so trivial an employment as 
counting the bundles. 
It arises from the two cost*, 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- 
sertions, its effect is very opposite from that of the supra spi- 
natus, 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 
shoulder-joint. 
OF THE MOTIONS OF THE HUMERUS. 
Having thus described all the muscles which moves this 
bone, I shall review the order in which they are arranged, and 
mark their place and effects. 
To distinguish clearly the function ofv each muscle, we 
have but to mark the point to which it is attached. 
1. Those implanted above the head of the bone must raise 
the arm. No>v 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 pectoValis 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 t( res major, both ol which pull MUSCLES OF THE ARM, &c. 
181 
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, that their strength and their ten- 
dinous connexions 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 increa- 
sed. Here, in the muscles arising from the scapula, power is 
sacrificed to the firmness of the joint, and they are all im- 
planted closely round the head of the bone. 
The connexion 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 fiat 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 anconeus for 
extending. 
LXXVIII. Biceps brachit 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 
feel 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, kc. 
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 fore- 
part 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. <?.) it will assist the supin- 
ators. Since both its heads are from the scapula, it will occas- 
ionally move the humerus, as well as the fore-arm. 
LXXIX. The brachialis internus lies immediately under 
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 
from the forepart of the humerus. MUSCLES OF THE ARM, Sec. 
183 
The longest head of this muscle is in the middle. It arises 
by a flat tendon ; from an inch of the edge of the scapula un- 
der the neck, and a little way from the 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 the 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 tfte 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 hu- 
merus, all the way down, and joins just where the second head 
joins (*. 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 strong- 
ly 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 to'o simple to admit of any further 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 re-enforced 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 the sheath to be 
fixed to the outside of the humerous, 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, enclosing its muscles in a very firm and close sheath; an«i 184 
MUSCLES OF THE ARM, &c. 
it sends partitions down among the several layers of muscles 
in the tore arm, which gives each of them a firm hold. 
LXXXI. The ancomus 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-ARM, 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 
arranged and classed with much care, explaining to the stu- 
dent 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, give 
both origin and strength to the muscles which lie undtr it, 
which divides the several layers one from another, and htlps 
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 v7eb of ten- 
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 
connexion 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, which 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 violent actions 
which are to ensue. I hus, 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 
and ulna, enabling those bones to give a broader origin to the MUSCLES OF THE ARM, &c. 
185 
muscles, establishing a strong connexion among the several 
layers, and making the dissection more difficuh. 
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 supiue. This is pronation and 
supination. The muscles which perform these motions are the 
pronators and the supinators, and the motion itself is best 
•exemplified in the turning a It :y 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 
plexors and extensors of the carpus. 
3. The bending and extending of the fingers cannot be mis- 
taken, and therefore the flexors and extensors ol the fingers 
need not be explained. 
These muscles are denominated from their uses chiefly ; but 
if two muscles perform one motion, they maybe 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 ftexor profundus, (i. e.) 
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 their 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 two 
points, and have but two uses. 
This assertion shall be afterwards qualified with a few excep- 
tions ; but at present it shall stand for the rule of our demon- 
stration ; for all the muscles arise from two points, the exter- 
nal and internal condyle. The internal condyle is the longer 
one, and gives most power: more power is required tor 
bending, grasping, and turning the hand inwards ; therefore 
all the muscles which bend the hand, all the muscles which bend 
the fingers, 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 186 
MUSCLES OF THE ARM, kc. 
is little resistance to opening the hand and little power is re- 
quired in extending the fing. rs; and so all the muscles which 
extend the wrist or the fingers, or roll the hand outwards to 
turn it supine, arise from the external condyle. 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; the 
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, 
bending the wrist. 
DIGITORUM SUBLiMIS, 
PROFUNDUS, 
LONGUS POLLICIS, 
bending the fingers 
and thumb. 
And, lastly, the pronator qiiadratus, which is the single ■ 
muscle out of that scheme which I have proposed.* 
LXXXI1. The pronator teres radii is of the outermost 
layer of muscles, is small and round; named pronator from its 
* Mr. Charles Bell in his Lecture, varies this arrangement. He observes thgt 
a kind of artificial memory of the muscles of the fore-arm may be had, by arrang- 
ing them in numbers : for example, if we take the biceps 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, then the muscles go in threes—thus: 
For the motion of the wrist, three flexors, tbeulnaris, radialis, and medius, com- 
monly called palmaris longos. Three extensors, ulnaris radialis longior, and bre- 
vier. Three pronators, the teres, quadrates, and the mass of flexor muscles. 
Three supinators, the supinator Iongus, brevis and biceps cubiti. There are three 
extensors of the fingers, extensor communis digitorum, extensor primi digiti, ex- 
tensor minimi digiti. Three extensors of the thumb, extensor primus, secundus, 
and tertius. Three flexors of the fingers and thumb, flexors digitorum sublimis, 
flexor digitorum profundus, flexor pollicis Iongus In the arrangement of the mus- 
cles 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 
better distinguished by their insertion : thus, all muscles inserted into the radius 
turn the wrist, and thus the supinator Iongus, the supinator brevis, the pronator 
tores, the pronator quad rat us, and the biceps, are employed in turning the hantf MUSCLES OF THE ARM, &c. 
187 
office of turning the radius, and teres from its shape, or rather 
to distinguish 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 radi- 
us ; 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 longus 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. 
sublimis ; 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 deltoides is 
thought to form, 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 OT THE ARM, kc. 
not arise from that muscle, but comes clown 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 when the muscle is 
found. i he aponeurosis, which covers the palm, is like the 
palm itself, of a triangular figure ; it begins from the small 
tendon 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 metacarpal 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 hone, there are eight in all, which 
form canals for the tendons of the fingers,.and for the lumbri- 
cales 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 pisifor ne, 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 flexor 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 sub- 
limis, profundus palmaris, &c.; consequently this muscle not 
only arises from the internal condyle, but also from the inter- 
muscular partitions (as from that betwixt it and the sublimis:) 
it forms a long tendon, which, becoming at last very small and 
* There is a great irregularity in this muscle; it is frequently wanting, and it is 
not uncommon to find two. We have found more than once, that the tendinous 
part of the muscle was next to the condyle, and the fleshy part connected with 
fascia palmaris. MUSfcLES OF THE ARM, Sic. 
189 
round, runs under the annular ligament: it runs in a gutter 
peculiar to itsell ; but in this canal it is moveable, not fixed : 
it then expands a very little, and is inserted into the meta- 
carpal bone of the fore-finger, also touching that which sup- 
ports 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 flexor carpi ulnaris is a long muscle, 
much like the former ; but as its course 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 par- 
tition, 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 muscles. 
This is to balance the flexor radialis: acting together, they 
bend the wrist with great strength ; and when this muscle 
combines in action with the extensor carpi ulnaris, they pull 
the edge of the hand sideways. 
LXXXVII. The flexor digitorum communis sublimis, 
is named sublimis from being the me re superficial of the two1 
muscles; perforatus, from its tendon bei .g perforated by 
the tendon of that which lies immediately below. Jt 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 
coronoid process of the ulna; and from the upper part of the 
radius, at the sharp ridge. By these origins, it becomes very 
fleshv and thick ; and, a little above the middle of the fore arm, 
divides into four fleshy portions, each of which ends in a slen- 
der 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 annular 
ligament of the wrist. At this place, a culluier stringy tissue 
connects the tendons with each other, and with the tendons 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 ap- 
pear 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 begins, 
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 opposite 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 
numerous ; for this one not only moves the fingers on the 
metacarpus, but the hand upon the wrist, and even the fore- 
arm upon the arm. 
LXXXVIII. The flexor dtgitorum profundus vel peu- 
forans, has so nearly the same origin, insertion, and use, so 
that the description of the last is applicable to this n.uscle 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 
tubercle 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 of 
the radius, and also, in some degree from the inter-muscular 
membrane which separates this from the sublimis. MUSCLES OF THE ARM, &c. 
191 
This muscle is small, we may say compressed above; but 
•it grows pretty strong and fleshy, near 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 sublimus, 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 sheatns 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 na- 
tural 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-fin- 
ger, 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 connexion 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 tendinous 
threads. 192 
MUSCLES OF TIIE 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- 
nales, as chiefly useful in playing upon musical instruments. 
XC. The flexor long us pollicis is placed by the side of 
th sublimis, or perforatus, and iies 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, (e. i.)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 sublimis. 
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, accasionallv, the wrist upon the radius 
and ulna. 
XCI. The pronator qyADRATus, so named from its shape 
and form, 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 iu length and breadth. Its MUSCLES OP THE ARM, &c. 
193 
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, ail 
arise from one point, the external condyle of the humerus, and 
are all delivered in this list: 
The extensor carpi radialis long ion, 
The EXTENSOR carpi radialis brevior, 
The extensor ca'rjpi ulnaris, 
■ all extend the wrist. 
The supinator longus,—turns the palm upwards. 
The extensor communis digitorum, extends all the fingers, and 
unfolds the hand. 
The EXTENSOR PRIMA INTERNODII 
POLLICIS, 
The EXTENSOR SECUNDI INTERNODII 
POLLICIS, 
*phe EXTENSOR TERTI INTERNODII 
POLLICIS, 
extend the several joint's of 
of the thumb. 
The extensor primi digiti vel indicator,—extends the fore- 
finger. 
The extensor minimi digiti vel AuiucuLARis,—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 the deep hollow, for th.e 
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; 
for though there is a large mass of flesh on the inner side ol 
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- 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 flexor 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 from 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- 
comes 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, Sec. 
195 
brevior, extensor digitorum, extensor minimi digiti, extensor 
carpi ulnaris. 
The extensor carpi radialis brevior arises from the order 
condyle of the humerus, by the common tendon ; it also arises 
from the aponeurosis, which 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 whole 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 meta- 
carpal 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 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 digitorum 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 TIIE ARM, kc. 
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 brevior, 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. Having 
passed this ligament they diverge and grow flat and large. And 
they all have the appearance of being 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 the 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 fing-rs. 
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. 
T he use ot 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. 
XCVII. The extensor minimi digiti, named also auri- 
cularis, from its turning up the little finger, as in packing 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 ? MUSCLES OF THE ARM, &c. 
197 
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 the 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 wtth the tendons both of the ring finger, and ot 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 off 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 is 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 two or three, 
sometimes four fleshy slips, with distincttendons, which, cross- 
ing the radius obliquely, slip under the external ligament ot 198 
MUSCLES OF TIIE 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 thuiftb, 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 fingers, 
be an extensor of the wrist: and it evidently must, from its 
oblique directions, assist in supination. 
XCIX. The extensor secundus pollicis is longer than 
the first. It is named by Douglas the extensor secundi inter- 
nodii pollicis : by Alhinus, 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 j 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 interrosseous 
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 j 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 tertius 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 with 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 die 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. T his 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. MUSCLES OF THE ARM, &c. 
199 
CL Indicator.—The extensor indicis proprius has 
very nearly the same origin, and exactly the same course with 
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 wrist. 
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, which 
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 ; 
but most especially for the lateral motions of the fingers, and 
which are named adductors, abductors, and flexors, 
when 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 of the hand; but as there is little 200 
MUSCLES OF THE ARM, Sec. 
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 interrossei externi 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 three distinct muscles; 
one to puli 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. 
1. lumbricales, which bend the fingers. 
2. abductor pollicis, removing the thumb from the fingers. 
ARRANGEMENT OF THESE.MUSCLES. 
3. 
FLEXOR AND OPPONENS 
POLLICIS, 
ADDUCTOR POLLICIS, 
carrying the thumb towards the 
palm as in grasping. 
4. ABDUCTOR INDICIS, 
which carries the fore-finger towards the 
thumb. 
ABDUCTOR MINIMI DIGITI," 
ADDUCTOR MINIMI DIGITI, 
FLEXOR MINIMI DIGITI, 
which bend the little-finger, and 
carry it, like the thumb, out- 
wards or inwards. 
5. 
which are small muscles, lying betwixt the me- 
tacarpal bones, and assisting the lumbricales 
in bending the fingers, and perform the lateral 
motions of the fingers. 
6. IXTEROSSEI 
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 matacarpal of the 
mid-finger, and goes to the inner edge of the thumb. 
CIII. The abductor poi.licis is onlycovered by the com- 
mon integuments. It begins a little tendinous from the out- 
side of the annular ligament, just under the thumb, aud 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 MUSCLES OF THE ARM, &c. 
201 
does not stop here ; for this flat tendon is now expanded into 
the form ol 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 extenson. 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. 
Aloi .us 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 pot.licis 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 office 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 make 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 pollicis 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 metacarpal 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- 202 
MUSCLES OF THE ARM, See. 
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 office of this muscle is to bend the first joint upon the 
second, and the metacarpal bone upon the carpus : and indeed 
the office of this, and of the opponens, is the same. It is in 
the tendons of this double-headed muscle that the sesamoid 
bones are found. 
CVI. The adductor pollicis arises from the metacarpal 
bone of the middle-finger, where it has a flat extended base. 
It goes from 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 5 
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 deltoides 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 ball 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. 
CVII. The abductor minimi digiti is a thin fleshy mus- 
cle. 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 pisiform, and metacarpal bone of the little-finger, 
and from the outer end of the annular ligament. It is inserted 
laterally 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 MUSCLES OF THE ARM, &c. 
203 
so much the same, that I have marked the last as a flexor; 
the little difference 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 former muscle. Its origin is from the hook of the unci- 
forme 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 
Diogenes’ cup. 
CX. The abductor indiois 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 lumbri- 
cales in shape and size, and in office resemble the adduc- 
tors 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 extending the 
fingers ; they at the same time perform 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 carpal 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 with 
most particular care, marking the degree of obliquity, and 
ascertaining precisely their office, and giving particular names 
to each, as prior indicis for the first external; all which I 204 
MUSCLES OF RESPIRATION, 
forbear mentioning, because they must he more liable to per- 
plex than assist: if we but remember their common place and 
office, it is enough. The tendons of the flexor muscles bend 
round the finger, along with the interossei and iumbricales, 
for a surer hold; consequently the tendons of the Iumbricales, 
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 crossed with m;my 
smaller ones. These muscles are related either to the arm, 
to the ribs, or to the spine, (?. e.) the vertebrae, 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 musculus patientiae, the rhomboides, the latissimus dorsi, 
belong to the arm. The serrated muscles which lie next 
under these, are the muscles of rt spiration, and belong to the 
ribs ; while the splenius and com plexus, the muscles of the 
neck, the longissimus dorsi, sacro-lumbalis, and the quadratus 
lumborum, which are muscles of the back, and the innumer- 
able smaller muscles which lie betwixt the vertebrae, belong 
entirely to the spine. 
Respiration is indeed performed chiefly by the muscles of 
the belly, that is, in ordinary and easy breathing. In high 
breathing, the difficulty is releaved 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 svhich are appropriated to the ribs, perform- 
ing no other motions, are, 
1. The SERRATUS POSTICUS 
SUPERIOR, 
"which comes from the neck, 
and lies fleshy over the ribs, 
.co pull them upwards. 
'which comes from the lumbar 
vertebrse, and lies flat on the 
lower part of the back, to 
pull the ribs downwards. 
2. The SERRATUS INFERIOR 
POSTICUS, 
which are twelve flat mus- 
cles arising from the trans- 
verse process of each ver- 
tebra, and going down to 
the rib below, they raise the 
ribs. 
3. The LEVATORES COSTARUM, 
"which lie betwixt the ribs, 
and fill up all the space be- 
twixt rib and rib; they also 
raise the ribs. 
4. The INTERCOSTAL MUSCLES, 
And there may be added to these, that muscle, which, lying 
under the sterni, and within the thorax, is called triangu- 
laris 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 verte- 
brse 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 nuchas 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 vetebrse of the back, and the three 
uppermost vetebrse of the loins. Their origin, like that of 
the latissimus, is by a thin tendinous expansion ; it soon be- 
comes fleshy, and, dividing into three, sometimes four fleshy 
strips of tongues, each of them is inserted separately into the 206 
MUSCLES OF RESPIRATION, 
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 mus- 
cles. The first of the levators arises from the transvere pro- 
cess 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 be- 
low, being very small and tendinous at either end ; but the 
three 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 downwards* 
Thus, the levators costarum are a succession of small mus- 
cles, arising from the transverse processes of the vtrtebrae, 
and going to the angles of the ribs, beginning from the last 
vertebra of the neck, and ending with the last but one of the 
back. They lie under the longissimus dorsi, and sacro-lum- 
balis ; and often they have connexions with these muscles, 
sometimes very close. 
CXVI. The intercostales externi run obliquely from the 
lower 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 backward 
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 heard Dr. Monro explain the office of 
the intercostal muscles by a diagram, deducing from that argument, tjje iflorfc 
powerful effeet of all muscles having oblique fibres. OR, OF THE RIBS. 
207 
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 
supracostales, these have been named infra costales, and 
costarum depressores PROPRii, They were discovered by 
Verhein, and bear his name ; they were explained as depres- 
sors of the ribs by Haller, but they are little different from 
the intercostals in form, and not at all in office, for they raise 
the ribs, along with the intercostal muscles. 
CXVII. 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 triangu- 
laris sterni, have been disputed; but if the first rib be more 
fixed than the other ribs, then the intercostals, proceeding 
downwards, 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 
$own the ribs. 208 
MUSCLES OF THE 
CHAP. V. 
MUSCLES OF THE HEAD, NECK, AND TRUNK. 
The serratus superior posticus being raised, the splenii 
comes into view, and the splenii being also lifted, the coin- 
plexus is fully exposed. 
CXVIII. 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 complexi. 
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 occi- 
pital 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 nuchae. 
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 vertebrae of 
the neck. This portion may be dissected apart, and has been 
considered by many as a muscle, the splenius colli of Al- 
binus ; 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 vertebra of the hack, and is implanted into the transverse 
processes 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 complexus is named from the intricacy of its HEAD AND NECK. 
209 
muscular and tendinous parts which are mixed; from the 
irregularly of its origins, which are very wide, it has the names 
of complexus implicATUi> trigeminus, by which the stu- 
dent is warned by the diificulty of understanding this muscle. 
It lies immediately under the splenius ; arises by distinct 
tendons, with ten or more tendinous feet from the four lower 
transverse processes of the vertebrae 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 complexus, and naming the lower part of the 
muscle complexus, 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 
tendons 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 
larger 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 
middle tendon that it is called biventer. 
The complexus 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 210 
MUSCLES OP THE 
the biventer, and mixed with it. This I have chosen to ex- 
plain, lest the student should be embarrassed by false names ; 
referring him to the first paragraph for the true and simple 
description of this muscle. 
CXX. Trachelo-mastoideus.*—The last muscle is often 
named complexus major, and this complexus minor ; but 
a fitter name is the trachelo-mastoideus, from its origin 
in the neck, and its insertion in the mastoid process. 
Its origin is from the three first vertebrae 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 m 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 capitas. 3. The splenius cERVicis. 4. The 
trachelo MASTOIDEUS. 
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; obliquelv, when one acts alone. 
The recti muscles are two deep-seated muscles, which go 
immediately from the vertebrae 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 fl shy* 
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 directly 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 TRACHELO-MASTOIDEUS, tile M*STorei5tTS EATER alts, the CAPITT9 pah* 
'PKRTjtcSj the complex minor : by some it is considered m a part of the complexes. HEAD AND NECK. 
211 
oblique direction the uppermost, as being much shorter, has 
been named obuquus minor, the lower one obliquus major. 
CXXIll. The obliquus superior 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, tor the 
occipital co 'dyles standing obliquely, do not permit the rota- 
tory motion of the h ad on the first vertebra. Its insertion in- 
to the occiput is under the splenous 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 
gn-at power, by the lateral projection of ihe atlas giving it a 
lever power. The first vertebra or atlas rolls on the tooth-iike 
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 k ins are the 
qUADRATUS LUMBORUM, SACllO-LUMB ALIS, and LONGISSIMUS 
BORSI. 
The sacro-lumbales 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 
muscle, I shall describe it first for the sake of a connexion 
which vvill be presently understood. , 
CXXV. The qua dr 'Tus 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 
back 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 vertebrae, it takes hold of the points of 
the transverse processes of each, by small tendinous slips ; so 
that we are almost at a loss whethertoconsider these as new ori- 
gins or as insertions; but its chief insertion is into the lower 
edge of the last rib, and a small production of it slips under 212 
MUSCLES OF THE TRUNK. 
the arch of the diaphragm, to be implanted into the body or 
forepart of the last vertebra of the back. 
The longissimus dorsi and sacro-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; lor, first externally it appears a broad, flat, 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 sarface 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 vertebra 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 opposite to the lowest rib, the longissimus dorsi and sa- 
cro lumbalis break oft' from the common tendon ; and the lon- 
gissimus keeps close by the vertebrae, 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 thenine or ten uppermost 
•ribs. Another set of heads, which are not so well seen as this MUSCLES OF THE TRUNK. 
213 
set, because they lie more under the muscle, are small, neat 
and tendinous ; they go in an opposite direction, viz. inwards, 
and upwards ; keep closer by the spine, and are inserted into 
the transverse processes of the vertebrae ot 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. 
CXXV11. The sacro-LUMbalis separates Irom the longis- 
simus dorsi at the last rib,and is a Hatter and less fleshy muscle: 
its twelve tendons are flatter than those ot tile 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, (z. e.) farthest out upon the chest, are 
the shortest. It has a flat tendon for each rib, which takes 
hold upon the lower edge of the rio. 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 Irom the surface ot each rib, at 
least of the six or seven lowest ribs, a small slip ot flesh, which 
runs into the substance of the sacro-lumbalis, and mixes with 
it; and these fleshy slips go by the name ot the additamen- 
TUM AD SACRO-LUMBALEM or MUSCULI ACCESSGRII. 
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 longis'simus dorsi, and 
the other a slip of the sacro-lumbalis, while others have descri- 
bed them as distinct muscles, having but slight connexions with 
the longissimus and sacro-lumbalis. Their proper names are 
CERVICALIS DESCENDERS, llnd TRANSVERSALIS COLLI. 
CXXVTII. 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 irom 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, per- 214 
MUSCLES OF THE TRUNK. 
haps it would be better to consider it a continuation of the ac- 
oessorii ad sacr. lumbal.* 
CXX1X. The transversalis colli is that which Sabitier 
refers to the longissnuus dorsi; but it is a distinct muscle, ari- 
sing partly tendinous, and partly fleshy, from the five upper 
transverse processes of the back ; lies betwixt the trachelo- 
mastoideus and the cervicalis descendens j 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- 
nexion with any other muscle. 
The quadrat; s 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 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 ; 
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 descendens, so far, that the slip is in- 
planted into the transverse processes of the neck. And, secondly, the feet ot the 
cervicalis descendens begin under the last tendons of the sacro-lumbalis, so as to 
have the appearance of arising from its supplementary muscle, the additamentum, 
and being a part of it; and indeed Sabitier hit* described it according to tliis view. MUSCLES OF THE TRUNK, 
•tfs the spinous, transverse, and oblique processes of the ver- 
tebrae, and the bulging heads and angels 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 continutiy 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 DORSI. 
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 connexion as to give it the 
form and name of a single muscle, the multifidus spin,*:. 
4. and 5. There are yet smaller muscular fasciculi which 
stand perpendicularly betwixt every two transverse and every 
two spinous processes ; thence they are named inter trans- 
VERSAR1I and INTER-SP’NALES. 
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-SP IN A LIS, or transverso-spinalis colli. 
It arises from the transverse processes of the six upper verte- 
brae of the back, and is inserted into ail the spinous process 
of the vertebrae 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.* 
CXXXI. 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. 
215 
• The trawsversalis cervicis (vide p. 214.) is that which goes from the 
transverse processes of the to the transverse processes of the neck; 
while this, the spin alts cf.rvicis, goes from the transverse processes of the 
hack to the spines of the neck. 216 
MUSCLES OF THE TRUNK. 
XXXII. The semi-spinalis dorsi arises from the trans- 
verse processes of the seventh, eighth, ninth, and tenth ver- 
tebra 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 vertebra 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 vertebra 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, lrom 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- 
tebra. 
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 bundles arises ; for the 
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 spinae, 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 
* Tlrs is of course the thansverso spinalis dorsi of Winslow. 
j- TRANSVERSO-SPINALIS LUMBORUM, SACER ; SEMI-SriNALlS INTERNUS, Sive 
$ransverso-spinalis dorsi, semi-spin alts, sive TRANSVERSO-SPINALIS colli, 
pars interna.—Winslow. Thansversalis lUMBonuM, vulgo sackr. Trans- 
tebsaus dorsi. Transversal!* colli. 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 qick 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-transversales 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. betwixt the atlas and dentatus ; and it is there, that 
Albinus counts his inter-transversalis cervicis, prio- 
res laterales, See. The inter-transversarii are wanting in 
the back, giving place to the ligaments, 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 mo- 
tions 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. 
CXXXVI. The pl atysma-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 Platisma-moides is also named mitsculus cctaxeus iatissimus com. 218 
MUSCLES OF THE TRUNK. 
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 sterno-mastoideus, and cleido-mastoideus; 
a more common name is the sterno-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 lamboidal suture. When one of the mastoid 
muscles acts, it turns the head to one side ; when both act, 
they pull the head directly forwards. 
CXXXVIII. Rectus internus 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 is 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 
foramen 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- 
wards, it is inserted into the occipital bone, near the condyle. 
CXL. And the rectus capitis lateralis is another small 
muscle 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 immedi- 
ately under the exit of the great jugular vein. 
CXLI. Longus 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 vertebrae 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 tendinous MULCLES OF THE TRUNK. 
into the forepart of the second vertebra of the neck, where 
the opposite large muscles meet in one point almost.* 
All these muscles, which lie thus flat upon the plain surface 
of the vertebra 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, 
CXLII. The scalenus I consider as one muscle; for it is 
one in origin, insertion and office. Its origin is from the 
whole 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 vertebra 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 divisions 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 
calenus, 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 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 
arses from the transverse processes of the fourth, fifth, and 
si:th vertebrae. It is inserted into the upper edge of the 
se:ond rib, about an inch or more from its articulation tvith 
th spine. 
The first head is tendinous and fleshy at its insertion into 
tie rib; but the second and third heads are tendinous, both 
i their origins and insertions. 
The nerves pass in the interstice betwixt the first and se- 
oncl portion. 
The office of the scalenus muscle is to pull the neck to one 
ide, or to bend the head and neck forward, when both act; 
tnd when the neck is fixed backwards, they may perhaps raise 
:he ribs; for asthmatics are observed to throw the head back- 
wards, in order to raise the chest with greater power. 
219 
* The longus colli muscle is in part covered by the rectus major. 220 
CHAP. VI. 
OF THE MUSCLES OF THE ABDOMEN, AND OF 
THE DIAPHRAGM. 
The abdominal muscles covering 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 back 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 faeces 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 herniae 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 descendens 
declivis and major are added, because it is the outermott of 
all the abdominal muscles ; because it is the largest, covefng 
all the side of the abdomen with its fleshy belly, and all he 
forepart of the abdomen with its broad expanded tend<n ; 
and it is called declivis, or descendens, because its fiehy 
belly begins above, upon the borders of the thorax; and ie- 
cause both its muscular and tendinous fibres, which lie parl- 
lel to each other, run obliquely from above downwards ad 
inwards. 
2. The obliquus internus is named from its being with* 
the first, and has the names of ascendens'vel minor supe- 
added, because its fleshy belly is smaller than that of th 
first, arises below, chiefly in the haunch bone, and all its fibre; 
go from below upwards. 
3. The transversalis lies under all the others, and ne: 
to the cavitv of the abdomen, and has but one name whio 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. 
5. The pyramidal 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 oblique muscle 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 seme 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 ; 
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, from 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 op the abdomen. 
distinct ligament, independent of the tendon, and stronger 
than it. f 
CXLIV. Obliquus internus abdominis.— i he chief part 
of this muscle arises thick and fleshy 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 vthat 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 
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 lumbai \eite- 
brse, and last of the back : from the whole spine of the os 
ilium internally, and from a part of the femoiai ligament. 
Upon the whole, its origin is like that of the inner oblique 
muscle ; its fibres go across the a’ldomen, and its tendon is 
inserted into the whole length ol the linea alba, cartilago 
ensiformis and os pubis. 
The succession in which these three muscles arise liom tne 
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, from 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 Gasper 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 the serratus and Jatissiraus dorsi muscles. AND OF THE DIAPHRAGM. 
223 
abdomen. But the transversalis, with the other abdominal 
muscles, are the antagonists of the diaphragm. 
CXLV1. The recti muscles cover the abdomen on its 
forepart, in aline 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 the 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 Sabbatier, were thought 
to have found the recti abdominus 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. Sabbatier, 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 by Massa to re- 
late to the penis, or by Fallopius, to belong to the urinary blad- 
der, their true use is only to resist 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 down to the 
pubes. 
1. The linea alba is the common meeting of all the thin 
flat tendons, and therefore we 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 line a 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 the 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 the 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 too intricate, and can hardly be proved by dissection. 
Cowper expresses his doubts about this doctrine of the tendon 
of the 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 obli que 
muscles go upon the 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 the 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. Ihe 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 in- 
stance it was a snorting of nature: “ so much a lusus uatVT'te, that accidents hs.*i 
this might he the cause of certain ruptures.” AM) OF THE DIAPHRAGM 
225 
into 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 abdominal muscles is that 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 abdomen viscera, 
the tighter is the slit drawn ; and the obliquity of the opening 
gives the direction to hernise of the groin, which aways 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 226 
MUSCLES OF the abdomen, 
share in the ring, the cord passes by their lower edge, but not 
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 the testicle, expanding and 
growing thin upon the upper end of the testicle, and gradually 
disappearing on the tunica vaginalis. 
CXLVIII, The cremaster 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, See. ; 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 spinus process of the illium 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 open- 
ings are forced, and the bowels descend. The umbilicus is 
very seldom forced by sudden exertion, for it is a very firm 
ring; but it is slowly dilated in pregancy, and hernia of the 
navel is infinitely more frequent with women than with men. 
The opening of the ring is often kept dilated by the bowels 
following the testicle when it descends ; forming the congenital 
hernia; most frequently of all, 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 ligament; the CRU. 
BAL ABCH ; the LIGAMENT of PAUPAUT ; the LIGAMENT of FALLOPIUS, &C. AND OF THE DIAPHRAGM, 
227 
mg j 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 hernise 
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 of the abdomen; for a wound 
of the abdominal muscles may not heal so neatly as pot to 
leave some small insterstice, 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 hernise 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 herniae 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 opening so particularly wide, that upon the 
slightest coughing or crying, hernise 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 effects 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 oblique 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 midriff; 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, MUSCLES OP THE ABDOMEN. 
228 
The diaphragm arises, by one broad fleshy attachment from 
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 diaphram. 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, 
eighth, and ninth ribs ; and from the bony parts of the tenth and 
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 lumborum muscles, is named ligamen- 
tum arcuatum ,• and from this another part still of the great 
muscle 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 ligamentum 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 muscle 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 feet, flat and glistening, and adhering closely to the shin- 
ing ligament with which the bodies of the vertebrae are 
strengthened; 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 thenjoin- 
ing, mixing, and crossing their fibres, form a fleshy belly, the 
lesser muscle of the diaphragm. 
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 surround the central tendon. The 
smaller muscle below meeting it, the two divisions give it a AND OF THE DIAPHRAGM, 
229 
pointed form behind j 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 ievel of the fourth true rib : the proper centre of 
the diaphragm is fixed by this connexion with the mediasti- 
num, that its motion might not disorder the action of the heart, 
which rest 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 oesophagus passes through the diaphragm, a 
little above this, and to the left side ; its passage is through the 
lowrer 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 oesophagus ; then surround 
it; then cross again above the hole ; so that they form the fi- 
gure of 8 : and the oesophagus is so apparently compressed by 
these surrounding 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 : “ Intri- 
cationes varise et vix dicendseirregular and confused, cross- 
ing 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 peritonaeum and 
pleura meet, and nearly touch each other through this open- 
ing, all round the vein. 
Hie 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 
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 faeces and urine, and 
assist the womb ; and vomiting, yawning, coughing, laughing, 
crying,hiccup,andthe 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 weeping 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 muscles of the parts of generation follow the division 
of the abdominal muscles more naturally than any other. 
The erector penis is a small and slender muscle, which 
goes over the crus penis, and braces it back to the pubes. 
The erectores are supposed (by pressing the penis against the 
pubis) to compress the great vein, and so cause erection. The 
ejaculator seminis is a muscle which 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 
the transversalis perinaei, which goes across the perinaeum, 
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 coccyGjEus is but a part of it, 
The detrusor uriNjE is the muscular coat of the bladder, and 
the sphinci*er vesica is not easily distinguished from the de- 
trusor urinse, being but the fibres of it, only thicker and stronger 
at the lower and narrower part of the bladder. 
The penis is composed of two crura, 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 urethrae, which surrounds the urethra, is attached to no 
bone, but begins just before the circle of the 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 the 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 the 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. 232 
MUSCLES OF THE FARTS OF 
The erectors lying thus on the sides ol' the penis, have been 
called colaterales penis or ischio-cavernosi from their 
origin in the ischium, and their insertion into the cavernous 
bodies. 
CLI. The transversalis perin/EI 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 several 
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 peri- 
n,ei alter.* 
This transverse muscle may by bracing up the bulb to the 
arch of the pubes, have some effect in stopping the vein on the 
back of the penis, and so producing ei'ection ; 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 ej aculator 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 the 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 transversalis alter, which, however, would be better named obliquus. In 
some bodies the transversalis is hardly perceptible, while in others 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 Lascars and Negroes, that on one side there 
is a very large muscle, while on the other there is a small transversalis, and a large, 
obliquus. 
We may also frequently see a muscle, the transversalis profundus ; it has exact- 
ly the same origin and insertion with the other, but lies deeper. At first view it, 
appears to be part of the levator ani, but the fibres run directly across, while those 
of the levator run in a descending direction. GENERATION, ANUS, AND PERINiEM. 
233 
upon 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. 
CLIIf. The sphincter ani muscle is a broad 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 very 
obvious reason, stronger in man than in animals. Some choose 
to enumerate two sphincter muscles, of which this is the ex- 
ternal, iV 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. 
CLIYr. The levator 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 
musculus 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 ischian. 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 spincter 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 the 
anus for the passage of the fteces, and supporting it, so as to 
prevent its being protruded. Thus, it is not for shutting the 
anus, as some have supposed, hut 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, as 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 234 
MUSCLES OF THE PAIM'S OF 
urine and faeces at the same moment. By surrounding the 
lower part of the bladder, and enclosing the prostrate .gland, 
and the vesicuise 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 vesicuise, 
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, vesku ae, prostrate and anus, this muscle 
produces that symoathy among the parts, which is often very 
distressing, as in gonorrhoea, the stone in the bladder, consti- 
pation, piles, and oth r 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 mu.scul.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 perinaeum, where the bulb begins, is the point into 
which all 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 
transversalis perinaei come across the perineum from either 
side ; and the levatoi ani muscle comes down to meet the 
sphincter, so that the spincter 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 
unskilfullv cut in performing lithotomv, it will be difficult 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 pas es 
by the side of the erector muscle, need not touch it, or 
• There is a muscde described by Mr. Wilson, as a levator, or compressor ureth- 
ra. The origin of this 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 am, being 
separated from the last muscle by a thin fascia, and some small veins. In order 
to make out this muscle distinctly, and with as large a tendon as Mr. Wilson de- 
scribes it, it is necessary to sacrifice several of the fasciae. GENERATION, ANUS, AND PERINJEUM. 
235 
touches it slightly, and by a sort of chance : it must not touch 
the ejaculator muscle ; for whosoever 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 ac- 
count of any danger which may attend wounds of them, but 
takes tnem 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.j 
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. 1’he next muscle is the sphincter 
vaginae, 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 vaginae and sphincter ani : in the 
two next muscles, viz. sphincter ani and levator ani, there is 
no cliff, rence, except that they are attached to the vagina in- 
stead of the penis. 
CHAP. VIII. 
MUSCI.ES OF THE THIGH, LEG, AND FOOT. 
MUSCLES MOVING THE THIGH-BONE. 
The muscles belonging to the thigh-bone arise all from the 
pelvis or trunk. The psoas magnus and ijliacus internets, 
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 their insertion, 
they turn the toes outwards, and bend the thigh. Other 
* Those anatomists who describe the origin of the ejaculator to be from the ra- 
mus ischii object to this. 
■f The detrusor urinae is but the muscular coat of the bladder; the sphincter 
vesiciae is but a densor fasiculus of this 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. I reserve for those books which describe the organs and viscera. 236 
MUSCLES MOVING THE THIGH-BONE. 
muscles come from the lower and forepart of the pelvis, as 
the pectin a lis, TRicePs, and obturator externus, which 
arise trom the arch of the os pubis, and go down to be im- 
planted into the linea aspera and lesser trochanter; and they 
pulling the thigli towards the body, are called the adductors. 
Others arise from the sacrum and back part of the pelvis, as 
the GLUTli, which coming directly forwards to be implanted 
into the great trochanter, puli back the thigh ; and a fourth 
set coming also from the internal surface of the pelvis; viz. 
the obturator internus 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. 1 he PSOAS MAGNUS, ILIACUS INTERNUS, PECTINEUS, 
triceps, obturator externus, which coming from before, 
are inserted into the line of the minor trochanter, and bend 
the thigh. 
2. The GLUT AT, GEMINI, PYRIFORMIS, OBTURATOR INTER- 
NUS, and qUADRATUs, 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, there 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, hut 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, (i. e.) 
rolline the trunk upon the limb. 
MUSCLES MOVING THE THIGH- 
1. THE THIGH IS MOVED BACKWARDS AND OU TWARDS. 
By the glutseus maximus, 
——— — medius, 
— minimus, 
which is! 
implanted < 
into the / 
linea aspera, 
trochanter major, 
top of trochanter. 
2. THE THTGH IS MOVED BACKWARDS, AMD ROLLED UPON ITS 
AXIS. 
By the pyryformis, 
gemini 
obturator externus, 
interims, 
<piadratus, 
which is 
implant- 
ed into 
the 
root of the trochanter. 
betwixt the trochanters MUSCLES MOVING TIIE THIGH-BONE. 
237 
3. THE THIGH IS MOVED FORWARDS AND INWARDS, 
trochanter minor, 
linea aspera. 
By the psoas magnus, 
iiiacus interims, 
pectinalis, 
triceps, 
which are 
inserted 
into the 
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 thigh 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 
bv 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 ol the thigh, which 
arises chiefly from the spine ot 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-enforced at the 
ancle ; and this 1 believe to be a juster history than tne 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 the musculus 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 r and as the fascia, at this part, takes at least a re- 
enforcement fiom 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 ten inous fascia has these connexions: 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 THIGH-BONE. 
sacrum ; the ligament of the joint, the great trochanter ; and 
the linea aspcra, 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 
division among the muscles of the thigh. 
CLVI. The fasci alis muscle — I he muscle is named ten- 
sor vaginae femoris. it arises from the upper spinous process 
of the illium, (J. e) from the forepart, or very point of its spine, 
by a tendon ot about an inch in length. It is very small at its 
origin, and at its termination. It is thick and fleshy ;n the 
middle,swellingout; it extends downwards, and obliquely bark- 
wards, almost to the middle of the thigh, and there it termi- 
nates obliquely, betwixt the two lamellae of the membrane to 
which it belongs. 
Its use is chi fly as an abductor, 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 lit tie 
effect in rolling the thigh, so as to turn the toes inwards, and 
oppose the Gemini. 
CLVII. Psoas Magnus.—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-bone, so as to 
preserve the equilibrium of the body. 
It is named from the psoas lumbus ; is a large round mus- 
cle, very strong, of great length, filling up all the space upon 
either side of the spine, and hounding the pelvis at its side. It 
comes from under the ligament arcuatum of the diaphragm ; 
for it arises first by its uppermost head from the last vertebra 
of the hack, then successively from each of the vertebrae of the 
loins. It sticks close to the lumbar vertebrae ; for it arises not 
onlv from the transverse processes hut from the sides of the 
bodies. These beads 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 psoas 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 
place of the acetabulum : it bends the spine upon the pelvis. 
This muscle is more regular in the monkey ; in the dog it is 
seldom wanting. It ts said to be more frequently found in 
women than in men ; in both, it often is not to be found : but 
sometimes, in strong and big men, three psoas muscles have 
been found. 
CL1X. 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 surfa.e : for below, it slides on the pubis as upon a pulley, 
and continues tendinous that it may bear the friction; but 
above it is unconnected, or it is connected only by loose cellular 
substance ; 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 two very powerful 
muscles. Their chief use is to bend the thigh, and more pe- 
culiarly of the lumbar one to support the body. 1 he 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 pubes, 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 pubes which is bounded on the upper part by the 
linea ileo pectinea, and on the lower by a ridge running Iroin 
the tuberous angle of the pubes to the upper part of the acata- 
bulum, and is implanted into the linea aspera, immediately be- 
low the trochanter minor, by a tendon flat and long, prettv 
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 puli the thigh forward ; 
to perform rotation, turning out the toe ; and, in certain posi- 240 
MUSCLES MOVING TIIE THIGH-BONE. 
tions of the limb, it will pull the thigh back, assisting the ex- 
tensor muscles. 
CLXL The triceps femoris is a broad flat muscle, with 
three h. ads, arising irom the os pubis, aud 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 heads, which lie in different 
layers, one above the other ; and have so little connexion 
among themselves, that they have been more commonly, and 
I think properly, described as three muscles. 1 hese 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 heen com- 
monly described under the names ol adductor primus or 
LONGUsJ ADDUCTOR SECUNDUS Or BREVIS J ADDUCTOR TEIITIUS 
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- 
le, not round, but flattened ; the bellv 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 magnus. 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 ; lor as the first layer con- 
sists of the pectinalis, triceps longus, and gracilis, this layer 
consists of t’.ie obturator externus, triceps brevis, and triceps 
magnus. The triceps brevis is exceedingly like the former, in 
risingnear 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 pelvis 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 the 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 (/. 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 right 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 thyroideum 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 242 
MUSCLES 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 hey 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 the obturator extern us at the upper part, and 
the triceps magnus, or third head of the triceps, all down to 
the condyle. 
Glutei.—There are three glutas muscles, each under the 
other, and each smaller han 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 gluteus 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 
fascicuke 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, surrounds its 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 gluteus medius or minor is smaller than 
the former but like it. It arises from all the outside of the 
ilium not occupied by the glutseus 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 glutseus maximus ; 
but its chief part lies before the glutaeus maximus ; 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 
glutaeus magnus in pulling the thigh backwards, and moving 
it outwards from the body. 
CLXV. The gluteus 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 glutaeus, below the root of the trochanter, and 
into the linea aspera; the middle glutaeus into the back and 
top of the trochanter ; and the smallest of the glutaei 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, upoh its ball or outer end. They are 
fleshy in their whole length. 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 pyramydalis, comes from 
the hollow of the sacrum, runs in the same line with the lesser 
glutaeus, 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 
vertebrae of that bone, -by three or four small fleshy digits ; 
and from the sacro-sciatic notch, it runs betwixt the glutaeus 
minor and gemini, and its round tendon is inserted betwixt 
them, somewhat connected with each.* 
The pyrifortnis, gemini, obturator interims, and quadratus, 
form what some anatomists have called musculi quadrige- 
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 mnsele is frequently divided by the great sacro-scistie nerve, 244 
MUSCLES MOVING THE THIGH-BONE. 
CLXIX. The obturator internus, once named marsu- 
pialis, or bursalis, 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 marsupialis, or bursalis. 
CLXX. The quadratus femoris 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 two 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 glutaei, 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 tve should conclude from MUSCLES MOVING THE LEG. 
245 
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 emplanted 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 t,high-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 glutaei 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 glutaei muscles. When the glutaei 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 glutaei 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 them so. Sabbitier call them the triceps femoris. 
These muscles, which all converge to the patella, and are in- MUSCLES MOVING THE LEG. 
246 
serted in it, are, rectus femoris,— or 
—vastus externus,—vastus internus. 
And these are all implanted by one tendon ; and 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 l'ound 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 
lenght, 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 cruraeus ; 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 Sabbitier 
calls the triceps femoris ; they may be more properly named 
the quADRicEPs 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 
externus from the great trochanter, and all the back pan and 
outer side of the bone ; and the vastus internus arises, in 
like manner, from the lesser trochanter, and ail the inner side 
of the bone, from the trochanter major all round to the origin 
of the cruraeus. 
CLXXII. The 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 the two muscles. 
Underthe 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 (subcrur.ei) 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 flat tendon which connects itself with the ten- 
don of the rectus femoris, 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 down 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. 
It arises from the forepart of the trochanter minor, just un- MUSCLES MOVING THE LEG. 
248 
der 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 leave 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 cruraeus at 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 rectus, and the vastus externus, internus and 
CRURiEus, 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 thesje 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 advantange 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.* 
* These muscles are in continual action; for their office is to resist the bending 
of the knee, which would happen by this encumbent weight 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, w alking, &c. Since by extending the knee 
they raise the weight 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 (voadhiceps, (t. e.) the rectus. MUSCLES MOVING THE LEG. 
249 
flexors of the leg. 
CLXXV. The sartorius or taylor’s muscle, is so 
named Irom 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 m 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 head 
of the tibia; its aponeurosis spreads widely, going over the 
whole joint of the knee, a thin sheet of tendon. 
brom the oblique position of the muscle, it might in action 
change its place ; but it is so far embraced by the facia 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 cen- 
tre 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 to 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. 
cruracus, and vasti, will weigh four pounds, while the biceps, kc. their antagonists, 
weigh but two pounds. This experiment was often repeated by the great Cowper, 
for Mr. Brown, who was delivering lectures on muscular motion. 
* Gracils, is from its smallness; rectus intebistus, is from its straight direction, 250 
MUSCLES MOVING THE LEG. 
This muscle runs also in a line so wide from the centre of 
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 mus- 
cles should come into play. 
CLXXV1I. The semitendinosus is so named from its 
lower half being composed of a small round tendon ; and as 
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 connexion betwixt the two muscles 
continues for three inches down from the tuber ischii; it then 
departs from the biceps, goes ohliquely inwards, and is 
flattened and contracted into a tendon, six inches from the 
knee and getting round the head 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. 
CLXXVIII. 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 two tendons of this muscle, the membranous tendon at the head, and this 
smaller one by which it is inserted, stand so obliquely, that the muscular fibres be This muscle has little connexion with any other. It lies 
under, or more particularly speaking, on the inside of the se- 
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 very 
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 which 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 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 glutaeus 
MUSCLES MOVING THE LEG. 
251 
Iwixt them must be very oblique; for the membranous tendon descends low upon 
the back part or edge, and the tendon of insertion begins high upon the fore edge 
of the muscle. 252 
MUSCLES MOVING THE LEG. 
magnus. The tendon 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 extensors and two flexor 
muscles. 
EXTENSORS. 
Gastrocnemius vel gemellus, 
Plantaris, 
Gastrocnemius internus vel soleus, 
Tibialis posticus, 
lying on the back 
part of the leg. 
Peroneus LONGUS, i 
BREVIS, l 
on the outside of the leg. 
The flexors are, 
The tibialis anticus, 
The PERONEUS TERTIUS, 
lying on the forepart of the leg. 
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 sural is. 
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 by 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. 
I he 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 flatitendon, very broad at its 
beginning, which unites with that of the soleus a little above 
the ankle. 
CLXXXII. Soleus,—This name is from its resemblance 
to the sosif 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 A chillis ; 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, &c. 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 Acbillis. 
CLXXXIII. Plantaris.—This muscle is named from a 
mistaken notion of its going to the planta pedis, or sole of the 
foot, to form the planter 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 Acbillis. 
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 
betwixt the inner head of the gastrocnemius and the solaeus; 
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 254 
MUSCLES MOVING THE LEG. 
groove which seems made- to receive it; and it is emplanted 
with the' tendo Achillis, into the inner side of the heel-hone# 
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 peroNjEi muscles are those which arise from the fibula. 
They are named from their length being different; the pero- 
Njeus 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 ins> rtion, going fullt round under the foot to the opposite 
side, while the shorter peronaeus 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 
anoth r 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 fibr s, 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. 
In passing the outer ankle it runs down through a cartilagi- 
nous pulley, or annular ligament, which also transmits the pero- 
naeus brevis : it leaves the peronaeus 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 bone 
of the great toe, and the great cuneiforme bone on which.it is 
founded. Under the eminence of th> os cuboides. it suffers 
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; so it presses to the ground MUSCLES MOVING THE LEG. 
255 
the 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. i'he peronseus 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, difficult to dissect. It is smaller at its origin, but 
increases in its fleshy belly as it descends ; and it is fleshy 
lower down than the peronseus longus. It is, like it, a penni- 
form muscle. i'he tendons of the two peronsei pass together, 
by the outer ankle, in the same ring; but the tendons cross 
each other ; for the peronseus longus is in its belly more for- 
ward. The brevis lies under and behind it, quite covered by 
it, and yet the 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 the 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 peronseus brevis, the shorter one, is small where 
it passes through the pulley, and expands when 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 peron.eus tertius 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 the peronseus longus and 
peronseus brevis. The peronseus 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 the same 
sheath with the peronseus 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 much connected with the extensor commu- 256 
MUSCLES MOVING THE LEG. 
nis digitorum, that there is often great difficulty in dividing the 
two. Thu action of this muscle balances the connexion 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 mterrosseous membrane 
below these. §ome 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 flesh 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 peronsei. 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 peronasus, 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 riaviculare 
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 anticijs crosses obliquely the 
forepart of the leg. It arises from the forepart and outside of 
the tibia, part of the fibula, anc\ 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 flesh, 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 ankle, it goes under the annula 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 peronseus 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 
and tibialis posticus, or behind, betwixt it and thesolseus. 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 cf the 
foot. The tendons of the extensor muscles keep with that of the 
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 
solseus is, 1st, the flexor pollicts ; 2dly, the flexor digi> 
TORum ; and 3dly, the tibialis posticus. 
CLXXXIX. The flfxor 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 peronsei. 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 j 258 
MUSCLES MOVING THE TOES. 
and therefore we should not be rash in cutting away the great 
toe, for in its consists not the strength of the foot only, but of 
the leg. 
CXC. The flexor longus digitorum pedis is named in 
addition the perforans, 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 
fingers. 
It arises from the back and inner part of the tibia, its whole 
length, that is, from the end of the poplitaeal 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 bv the other, and could be wholly supplied 
by it; it then passes over to the middle of the sole, and grow- 
ing flatter and thicker, 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 al! 
the muscles used in walking, Stc. MUSCLES MOVESG THE TOES. 
259 
CXCI. The massa carnea Jacobi Sylvii, or 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 Covvper considered 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 digitorum is also named the 
flexor sublimis 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, which form a split (like 
the perforatus of the fingers) for the passage of the long 
tendon. 
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 pha- 
lanx 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 THE 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 inwards 
and meets the other at an acute angle near the toes. 
CXCIII. The lumbricales must be dissected after the 
short 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 arise from the tendons of the long flexor, beginning just 
where the massa carnea ends in it: and the lumbricales are 
the flexores primi internodii; the short flexor muscle, the 
flexor secundi internodii; tlq| long flexor, the flexor tertii 
internodii digitorum. 
EXTENSORS OF THE TOES* 
CXCIV. The extensor longus digitorum eedis is very 
difficult to dissect, from its numerous adhesions. 
It arises properly from the head of the tibia, at its outer and 
forepart, just under the knee ; but it also has 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 peronsei 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 peronseus 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 be 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 interni; 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 iongus, that it is natural to describe them 
together. It is placed just where the buckle lies, upon the 
rising 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 increases 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 pas3 
under them nearly about the end of the metatarsal bones. 
Then one is emplanted 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 pollicis proprius is a very 
slender muscle running from the top of the leg to the second 
joint 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 outer- 
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 digitorum 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 down the 
leg : it is much strengthed 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 ten- 
dons, to the point of the inner ankle, forms a strong crucial 
ligament, resembling the annular ligament of the wrist; so 
that this, which is called the crucial ligament of the ankle 
or foot, is plainly but a strengthening of the common sheath. 
The remaining muscles in the foot are the interrosei, 
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 abductur. flexor, and adductor pollicis, 
which surround the great toe, something like those of the 
thumb; and the abductor and flexor minimi digiti, sur- 
rounding the little toe ; and there is a small slip of muscle, 
the transversalis pedis, which goes 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 wrhich 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 hone or phalanx 
ol 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. 
263 
CXCVIII. 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 cuneiforme 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 two 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 which 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 trans vers a lis pedis extends transversely across 
the sole of the foot 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 heads of the metatarsal bones together; but is it 
not evident, that this is one of many instances of muscles be- 
ing a more perfect support 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 the 
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. 
CCII. The flexo brevis minimi digiti is next, 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 hand. 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 exte ni are, like the correspon- 
ing muscles ot the hand tout m 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, upon 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. 
Tlv office of these muscles is to extend the toes. 
Plantar aponeurosis.—The palm and the sole are much 
exposed, and are especially 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„ 
sqch an origin is still less 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. Sabbatier 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 ap- 
pearance. Accordingly the part nearest the heel is thicke'r, 
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 lumbricales 
and short flexor muscles : under the outer one the flexors and 
abductor of the little toe ; and under the inner one the adduc- 
tor, flexor, and the abductors of the great toe. 
The uses of this great and very strong aponeurosis are ; that 
it protects all the parts, the blood vessels, muscles, and nerves 
that lie under it; that it supports the arch of the loot, 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- 266 
OF THE MUSCULAR POWER. 
cles ; which by their frequent and irregular adhesion to it, are 
very difficult to dissect: that it forms openings or rings, in 
which the tendons of the other muscles pass. 
CHAP. IX. 
OF THE MUSCULAR POWER. 
rn 
X HAT contractile power which resides in the muscular or 
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 know, 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 colour of the muscular 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 easy 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 
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 sub- OF THE MUSCULAR POWER. 
267 
ject 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 
Covvper thought that he was injecting with quicksilver, chains 
of bells jointed with each other. For thejhonour 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 
knowldge 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 way 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, have neither conciousness 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. 268 
OF THE MUSCULAR POWER. 
This irritable 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 verv 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 Goer- 
ter, the oscillation of Boerhaave, and the ionic power of Stahl. 
It is seen in the spontaneous and tremulous contractions of 
muscles when lacerated ; as in wrounds 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, without 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 muscle’s 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 
uepends : for the ligaments, tendons, bursae 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 
connexion betwixt the organization of a muscle and its con- 
tractile power, that the moment it dies its power is gone ; and 
the muscle which could lift a hundred pounds while alive, can- 
not bear the weight of a few pounds when dead. This latent 
powTer 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- 
* The irritability of a muscle is, perhaps, more properly the vis insita, or inhe- 
rent power called into immediate action, by the presence of stimuli; and as for the 
names of Tonic Power, Vital Power, and the rest, the terms are quite undefined, 
and may, perhaps, have referred rather to the combined effect of all the powers 
of life, and of all the properties of inanimate matter, of nervous sympathy, elas, 
ticity, and of muscular power combined OF THE MUSCULAR POWER. 
269 
dependent of nerves, and so little connected with feeling, which 
is the province ol the nerves, that upon stimulating any muscle 
by touching it with a caustic, or irritating with a sharp point, 
or driving the eiectric 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 
connexion 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 w hen 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 two 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 vis insita, 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 ; survives the 
life of the part, or the feelings of the whole system, as in uni- 
versal palsey, 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 connexion 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 system, 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 ho consciousness of present stimulus in 
* See a most ingenious dissertation by my pupil Mr. Fowler, the First writer in 
this country, on this very interesting novelty, where the operations of this new ex- 
citement are explained. 270 
OF THE MUSCULAR POWER. 
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, 
while others are obedient to the nervous power, and the in- 
fluence of the will. The 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 irritability, 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 owrn peculiar stimulus, 
and act in a continued and equal course. 
Thus, there are in the body twro 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; bv 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 itn- OF THE MUSCULAR POWER. 
271 
pression and the moving power. But nerves were never 
known to move under the influence 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 the 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 power is 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 weaknes 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 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- 
cal, and depend less on our spirital part: for life and exist- 
ence depends 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 
has 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, iungs, and stomach ; the sympathetic nerve 
to the heart, to the intestines and other viscera of the abdo- 
men : these nerves are appropriated and distinct. Now, this 
question occurs : if the irritable power be in these organs, it 
they be endowed with the quality of feeling their own peculiar 
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 connexion with that system to which they 
belong: that they may flourish in its health, and languish in its 
diseases; thgt 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 perfect, according to the conditions of the whole : 
and how 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 
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 with 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 ol 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 power re- 
cover by rest in the muscular fibres of a living system. 
The vis jnsita cannot be wearied nor exhausted; so the 
heart is unwearied in it function, or if languid or two violent 
in its actions, that must be from the power 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, we are sensible of cramps and irregular cor.o. OF THE MUSCULAR POWER. 
tractions, showing that they are still active, byt more loosely 
governed by the nerves, and not so fully under the command 
of the will. But the nernous 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 ail 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 at 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 oveY 
the system faster than the ordinary powers of life do; and 
the 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 ex- 
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-animate 
the nervous svstern, and recover that life, which seemed to 
273 274 
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 and source of life, owes its 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 ; 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 
allowed 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 
effectually exhausted ; no mark of irritability remains ; putre- 
faction copies quickly on : and so in those who die of the 
plague, of poison, of fevers, or of any sudden and violent 
disease, which 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 exhaust the vital 
power, 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 ceased 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 moveg 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 while the OF THE MUSCULAR POWER. 
275 
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; thenjt 
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 increase of 
power. The mastoid process and the occiput are as levers for 
the head ; the spines of the vertebrae 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 : sensibility and contractility 
are two distinct endowments of the living body, the one the property of the ner- 
vous matter, the other of the muscular fibre. When a sharp point is thrust into 
a muscle, it is not the muscular fibre which feels this injury, but the nervous mat- 
ter in intimate distribution with the proper fibre : and we have here, no more than 
on other occasions, a proof of musculsr contraction being the direct result of a 
stimulus to the muscular fibre. Sensibility must reside in a part, before that part 
he capable of receiving excitement, the contraction of the muscle is therefore tin 
conjoint operation of the nerves and muscular fibres. C. B 276 
OF THE MU SOUL AH 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 increase 
the power, nature has provided such a quantity of contractile 
power as to compensate for any loss of effect: so, in place of 
encreasing 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 immoveble end of the bone. Much 
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, 'ihus everywhere 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 not seeking to compensate for want of pow- 
er, 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 chieflv dwelU OF THE TENDONS, LIGAMENTS, 8cc. 
277 
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 
parts 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 which 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 
OF 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, tach 
muscle answering to its particular stimuli, and most of them 
obeying the commands of tile 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 nerves, 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 bursae, and 
all the apparatus 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 connexion 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 such 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 sensi - 
bility be ordered with such a relation to their office, as not to obstruct the play 
and motion of the limbs. C. B. LIGAMENTS, BURSiE, &c. 
279 
t>f strength, in health and disease, depends, at least, in some 
‘degree, upon the 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 loose 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, bting 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 others 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 bursse 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 on 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 wc 
advance in years and in strength, and in the arms of workmen 
it grows particularly thick and strongs 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 
with 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 be 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 bursae musosae, 
* The tendons are the continuation of the intersticial cellular membrane of the 
muscle; and I have succeeded in unravelling them into a web. C. B. LIGAMENTS, BURSAE, kc, 
281 
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 bow. 
The same inanimate substance still performs 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 peronsei muscles pass behind the ancle, and thus the 
vagina or sheaths of the tendons are connected with the 
tendons, periosteum, and other modifications of the common 
cellular 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 the 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, fascise, 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 ligament, 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 prevents 
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 snaps 282 
OF THE TENDONS, 
across, when 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- 
stance : 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 all 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 connexion 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 : 2ly, The same periosteum, thickened 
and strengthened by the adhesion of surrounding parts, so as to 
form the capsules for the joints: 3dly, The tendon 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 brawn of the 
leg where the ham-strings (whose expansion strengthens 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 bursa, 
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 no 
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, ligaments. LIGAMENTS, BliltSiE, &c. 
283 
bursae, 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 
embowelling 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 these 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 from this hard treatment; who was 
ignorant of this injustice that was done to him, while his cure 
was protracted and he was made a spectacle for a whole city. 
Without such cruel and inhuman practices we do not want 
opportunities of knowing, that in the Juiman body also, the 
tendons and bursae 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 suppurated fingers lying fiat in their sheaths, 
we draw them out with our forceps or touch them with probes 
without exciting pain. In the old practice of sewing 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 this pass without again entering a protest. The pain of a disloca- 
tion is excessive. ' It is the greatest which the ingenuity of man has invented as a 
torture, and so it is incorrect 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, admonishing us of that degree of 
violence which would be injurious to the structure. Yet they are certainly not 
sensible like the other parts of the frame, and very happily so, as then we could 
neither sit, stand, nor walk. 284 
OF TOE TENDONS, 
there is swelling and inflammation, with such adhesion of the 
parts as makes the patient lame ; after the slightest sprain, 
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 the 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 down 
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 ennumerated 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 
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 mucous bags, which accompany these tendons, and 
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 eve LIGAMENTS, BURSiE, &c. 
285 
Seels 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, but 
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 effusions; 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 
effusion of gelatinous matter round them is ganglion : suppura- 
tions in the tendinous sheaths is whitlow : the inflammation 
of. bursse 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 ; which sometimes stops by an effusion of callus and con- 
cretion of the bones, forming a stiff joint, but which oftener 
ends in hectic fever, diarrhoea, morning sweats, and extreme 
weakness ; so that the patient dies, exhausted with fever and 
pain. BOOK III. 
OF THE JOINTS. 
CHAP. I 
JOINTS OF THE HEAD AND TRUNK 
Almost every thing relating to the heads 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 anatomy 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. 
We 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 vertebrae 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 connexion 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 
be secured towards either side, and the obliquity of the joint 
JOINTS OF THE HEAD AND SPINE. JOINTS OP 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. We 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 vertebrae 
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 roiling 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: 
Ail 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- 
nexions resembling the common joints of the body; but the 
other vertebrae are united, each by its intervertebral 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- 
* This is part of what Winslow called ligamentum intundibiliforme, a 
funnel-like ligament, joining the first vertebrae to the occiput. 
fViz. Ligamentum transversale, or transversum : 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 the 
tooth-like process, and which go 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 fair round ligament of some 
strength ; there is nothing more than a few straggling fibres of ligament going from 
the point to the occiput, though Eustachius has drawn it round ar.d 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- 
vertebral substance; and so, by adhering to the intervertebral 
substance, they strengthen it. These ligaments cross each 
other over the interstice betwixt each vertebra, and are very 
strong. 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 sides. 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 
vertebrae ; yet the whole is so much continued, that is if 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 LIG AMENTUM COMMUNE ANTERIUS, FASCIA EONGITUDINALIS ANTERIOR, 
fascia eigamentosa, &c. It is from this ligament in the loins that the crura 
diaphragmatis arise, with tendons flat and glistening like the ligament itself, 
and hardly to be distinguished from it. 
fThev are named the t.igamenta subfiava crurum frocesbucm srisusonrm - JOINTS OF THE HEAD AND SPINE. 
289 
gether, 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- 
brae of the back, but not of those of the loins or neck, similar 
ligaments are found alst> betwixt the transverse processes.] 
Next, there is another internal ligament, wrhich 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 posterior or internal ligament.]; It begins at the 
occiput, lies flat upon the back part of the bodies of the verte- 
bras j at the interstice of every vertebrae it spreads out broad 
upon the intervertebral substance, doingthe same office within 
that the intervertebral ligaments do without. It is broader 
above ; it growTs gradually narrower 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 the 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 firmlv 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 vertebrae, and their intervertebral substances. 
There is yet a third internal ligament, which belongs entirely 
to the neck ; it is called apparatus ligamentosus colli ; it 
begins from the edge of the occipital bone, descends in the ca- 
nal of the vetebrae, 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 w at once ligaments for the bones, and a sheath for 
* These are named the membranjh interspinales ligamenta apipes spi- 
aauch comit antes. The ligaments which tie the points of the spines, run- 
ning from point to point, make a long ligament, which stretches down all the 
spine. 
' j- Called ligament a processum transvehsoruSt, and found only from the 
fifth to the tenth vertebra of the back 
f Fascia ligamentosa postica, fascia longitgdinalis, tostica,ligamen- 
tum COMMUNE POSTERII7S. JOINTS OF THE HEAD AND SPINE 
290 
the medulla.” But there is no such sheath as that called liga- 
mentum infundibiliforme by Winslow ; for either they are 
peculiar and distinct ligaments for the bones, such as I 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 connex- 
ion of the spinal marrow with the ligaments of the spine, is 
just at the hole of the occipital bone ; and for a little way 
down through all the rest of the spine, the connexion 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. 
The 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 is 
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 jawT, and with the 
hollow of the temporal bone. It moves with every motion of JOINTS OF THE HEAD AND SPINE. 
the jaw, facilitates the common motions, and prevents lux- 
ation ; but the joint is still more strongly secured by the 
strength of its peterygoid 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, 
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 breadth. 
.The tv. o 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 it 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 li- 
gamentum 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 ligamentum 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. 
i he 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 of the sternum, 
much in the same way that the ligamenta capitelli expand up- 
on the bodies of the vertebrae : a tendinous membrane also 
binds the cartilages of the ribs, one to another, crosses over 
the interstice, and so covers the intercostal muscles with a sort 
291 JOINTS OF THE 
292 
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 articulating 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 fcartilage, which 
rolls betwixt this head and the sternum. The cartilage is thin, 
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 ribs ; 
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. 
of the acromion and of the clavicle, are covered with a thin 
articulating cartilage ; in some subjects a moveable cartilage is 
also found here : it is a regular joint, and is very seldom 
obliterated ; yet its motion, though continual, is not very free ; 
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 the coracoid 
process, is tied down to it by ligaments ot considerable strength ; 
one comes irom the root of the coracoid process to the clavi- 
cle, and is called ligamentum commune conoides ; another 
from the point oi the coracoici process, is implanted into the 
lower or inner edge qf the clavicle, and is named ligamentum 
commune tr.APezoides ; trapezoid, 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 scapula. The ligamentum scapulae proprium poste- 
rius is of less importance, being that which completes the notch 
of the scapula into a hole, and gives attachment to the omo- 
hyoideus muscle. 
SHOULDER-JOINT. 
The shoulder is one ot the most beautiful joints, loose and 
moveable, very free in its. motions, but very liable to be displa- 
ced. 1 o 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 ‘encreases the hol- 
low of the socket, but still it is so shallow, that the humerus 
cannot lie 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 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 lacunae or bags, the 
common organ for this secretion through all the joints, and by 
a thinner exudation from those extreme arteries, which 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 „vf its structure, the shoulder is exceedingly loose, 
ai.ients l.hrovig' to be displaced : it has this loose structure, and 
sutrnmo -<set, that its motions may be free, but seldom is 
there Hje 'eat advantage gained in the human body, without 
a counjy.oalance of weakness and danger; and every where 
in the limbs we observe that a joint is weak and liable to luxa- 
* It is called glenoid cavity, from the Greek name of a joint, and the name * 
not absolutely appropriated to the scapula. 294 
.101NTS OF THE 
tion in propotion as its motions are free and large. Yet the 
shoulder-joint is not without some kind of deft nee ; its socket 
is shallow, but it is guarded by the largest projecting processes 
in all the body, by the acromion projecting and strengthening 
it above, and by the coracoid process within ; its ligament is 
lax, easily torn, and useful rather for confining the synovia, 
and keeping the head of the humerus 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 proprium triangulare 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 foramen 
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 bursae or mu- 
cous bags :* one under the tendons of the subscapularis ; one 
under the short head of the biceps muscles ; 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 he remembered, that the long tendi- 
nous head of the biceps muscle comes from the margin of jthe 
socket, directly over the ball of the os humeri, and tddom h 
the capsule, by the foramen ovale. fre' 
* Vide Monro’* tables of the bursae mucosa1., where all these parts are repre- 
sented, the knowledge of which is so very useful for the surgeon. 1 have opened 
this great bursa under the acrimon process, and let out four pounds of the pecu- 
'mucus and gelatinous lumps, with which the diseased bursa: are commonly filled. SHOULDER, ARM, AND HAND. 
295 
ELBOW. 
The elbow joint is formed by three bones; the humerus, 
radius, andjulna : 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 1m- 
mei’us. 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 which 
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 obliques lip of 
ligament 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 ; 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 bv 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 lubricate. JOINTS OF THE 
296 
to have its capsule strengthened at the sides : and the sides oi 
this, the elbow joint, are strengthened by two fasciculi, or 
ligamentous heads, w hich coming from the tubercles o: the 
humerus, spread a little upon the capsule, and adhere to it 
like part of its substance. One, front the outer condyle, 
spreads upon the neck of the radius, and sends a strong division 
to be attached to the rough spin 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 
coronarium, or annulare, because it encircles the neck of 
the radius ; annulare or orbiculare from its hoop or ring- 
like form : 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 ol 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 another ligament behind the internal lateral ligament, viz. risinjg from the 
external condyles 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 mo- 
tion of the joint laterally, but to check the flexion and extension of the arm ; the 
one being made tense by the flexion, the other by the extension, ot the fore-arm. 
But the capsule ought to be called membrana capsularis; it is not a ligament, 
and these which are called accessory are proper ligaments. The ligament which 
is on the fore part of the joint, anil which runs towards the Ligamentum Annu- 
lare, is properly called Accessorium Annuli Anticum ; it crosses from the ulna 
to the external condyle ; and another coming round from the olecranon, and being 
on the hack of the joint, Accessorium Annular JPosticum. 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 a 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 connexion 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 triangula- 
ris. 'New, this first joint, viz. of the scaphoid and lunated 
bones, the head of the radius, and the moveable cartilage which 
represents 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 lunated 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 capus ; 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 298 
JOINTS OF THE 
ligaments; for although the wrist 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 
lacunse 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 membrana 
capsularis sacciformis. Thus 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 
bone 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 very 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 surgeon, but which are so laboriously described under the titles of iigakhs- 
ta bsevia, obliq.ua tbaktsyehsaria, and piiorniA ossium carpi; for they do ir 
fact cross and traverse the carpus in every possible direction. SHOULDER, ARM, AND HANB. 
299 
tow 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,| 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 the 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 which 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 bursae mucosae, 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, liga- 
ments ARTICCLARIA. LATER ALIA, RECTA PERPENDICULARIA, &C. 
f These are named the licamenta istterossea. JOINTS OF THE 
300 
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 bursae, viz. those which lie in 
the palm of the hand, stop before they reach the first joints 
of the fingers, and then other longitudinal bursae begin from 
the first joint of the fingers, and go all along them to the last 
joint forming the sheath for the tendons to run in, which does 
at once the office of a strong ligament, binding them down in 
their places, and which is so lubricated on its internal surface, 
as to save the necessity of other bursas. 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 tile 
fingers, and are of the same nature with the bursae. Be- 
sides these, there are no distinct bursae on the fingers, but 
there are several about the wrist, and one especially of a consi- 
derable size at the root of the thumb.f 
CHAP. III. 
JOINTS OF THE THIGH, LEG, AND ANKLE. 
OF THE HIP-JOINT. 
The 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 head 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 
* LTGAMENTA VAGINALIA, LIGAMENTA CBUCIATA, FlIAXANGUMf &C- 
t Vide Monro’s Burssc Mucosk, THIGH, LEG, AND ANKLE. 
301 
is Filled up by a strong cartilaginous ligament, which goes 
across tilts gap, from the one point to the other, and from its 
going across is named the ligamentum libri c artil aginALi 
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 out layer. They unite together, so as to form the gene- 
ral capsule enclosing the ring-iike 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, continues 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, glutseus, 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-hone, 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 filled up with 
the synovial gland. It is wonderful 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 in 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 ; thence it is often reckoned as two ligaments, viz, 
EISAMENTUM TRANSVERBALE INTERNUM Ct EXTERNUM. 302 
JOINTS OF THE 
points certainly are ducts from which we can squeeze out 
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 mucqus 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 
massae adiposse 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. s 
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 tendinons 
fibres and the joint. That tendort 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 tc 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-en- 
forced both by its adhesion to the bones, and by the broad 
ex Y ti'n °f the vastus internus, sartorius, biceps, and other 
ir, There* which go out over the patella, it adheres to the cap- 
su i makes the 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- 
mentum posticum Winslowii. 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 flat 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 
externum longior, 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, aligament 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 the joint, flat upon the back of the cap- 
sule, and the one crossing a little 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 ofiiche 
tibia, betwixt its two cup-like hollows, and behind the tubsidte 
which divides these hollows from each other. While*'the 
* Often it is irregular, or in straggling fibres; but I have never found it wanting. 
Some strong, but irregular accessory ligaments 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 ot 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. I he 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 fimbriae 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 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 
* There is not attention enough paid to the origins of these ligaments from the 
femur; for it is the origin from the thigh-bone which determines their operation. 
The posterior ligament comes from the root of the internal condyle, and depth ot 
the semilunar notch, anterior to the centre of motion of the lower head of the fe- 
mur on the tibia; it is consequently stretched in extending the leg. The anterior 
ligament arises from the root of the external condyle, posterior to the centre of 
motion; it is consequently stretched in the flexion of the knee-joint. 306 
JOINTS OP THE 
larger than the other, whence they are named ligamentum 
alare majus, and ligamentum alare minus. 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 fimbricated ducts in their place, (viz. the hollow 
betwixt the condyles, where they are least exposed to harm ;) 
thence it has been long named the ligmentum mucosom. 
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. 1 hese tags by 
which the four points of the lunated cartilages are ti-.-d, are 
named the ligament a cartilaginUm lunatarum, 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 ligamentum 
TRANsversale commune, because it goes 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 the 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 bursas 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 helo <• the patella, and under the ligament of 
the patella, protecting it from friction, upon the head of the 
tibia. These bursae, I am persuaded, are often the seat of 
disease when it is judged to be in the joint itself. Hut the 
truth is verv easily known; for if a swelling appear under the 
patella projecting at the sides, 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 
complaint which is far less formidable than a swelling of the 
joint itself: I would almost say, easily cured; fo» openings 
into these bursae, 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 familar or easy thing, or 
think that they have done such operations safely, when pro- 
bably they were puncturing the bursae only.* 
These bursae mucosae lit 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 irregularly about the 
joint, belong partly to the bursae 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 superficial 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 contains 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, 
* I believe that the great bursa and the joint always communicate largely ; and 
that being consequently one continuous surface, the opening of the burs® would 
highly improper. 308 
JOINTS OF THE 
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 wreight; 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 
bursse mucosae, which complete the lubricating apparatus of 
the joint, and the mucous frenuloe 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 strength- 
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, which 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- 
fe-rius, 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, bv JOINTS OF THE 
310 
supplementary ligaments: First, a strong ligament comes 
down Irom 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 calcus and naviculare. This ligament, coming Irotn 
one point, and expanding to be inserted into a long line, has 
a triangular form, whence it is 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 dow'nwards ; 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 ligamentum fibula 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 oi the capsule, and is finally inserted into the 
heel-bone, this is named the ligamentum fibulae 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 
fimbriae 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 complu ation 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 nd 
complicated, that they cannot nor need not be explained, THIGH, LEG, AND ANKLE, 
311 
They pass across fr>m 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, Ike. 
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 effect 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 
apoeurosis plantaris pedis, which is not merely the 
aponeurosis tor 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 planter 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 off 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 bursae mucosae surround the ankle and foot in great 
numbers. None of them having any very direct connexion 
with the joint, and most of them accompanying the long ten- 
dons as they 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 suround the 
tendons of the tibialis posticus, and of the peronaei muscles, 
as they pass down behind the ankle, the sheath 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- 
naeus 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 bursae 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 bursae mucosae 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 joint 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 lower 
jaw, the vertebra, 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. Some 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 
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. THE 
ANATOMY 
OF THE 
HEART AND ARTERIES, 
BOOK I. 
OF THE HEART* 
CHAP. I. 
OF THE MECHANISM OF 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 number, 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 
receive 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 TIIE 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 5 of an auricle or smaller bag, which receives that 
blood and retains it till the action of the heart 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 principles 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 he 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 : 
in the chick we see its blood circulating over the yolk, (for the 
yolk is enclosed within the membranes of the uhhatched 
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 li fe : in those OF THE HEART. 
317 
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 warm 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 gc 
into the water; yet they have membranous lungs; nor indeet 
can the amphibia, as the Seal, the Porpoise, the Sea-Lion 
&c. dive and exist under wrater 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 othei 
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 water, if you 
force them : but if they can live long under water, 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 MECHANISE 
below the reservoir, having strength quite sufficient for 
ing both the blood of the lungs and the blood ol 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. 
13ut 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 biood which 
is sent by eacli 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 (o)—and auricle (ti)—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, bv 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 arms, the othcT Vol.l. 
f>/ f/t’ Mm 7/ 
t - 4 
N°3 
N° I 
X" 1 
N"4 
'/; i' .(et. flings the blood from ali the lower parts of the body ; they 
meet at (6) 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.—('b) 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, iike all its parts, is strong and irritable : it is filled 
by the returning blood ol the cavse; 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 bj 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) Isthe pulmonic artery,—the artery ofthelungs, 
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 byr 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 or 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.—(f) 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 farm is longer, its 
fleshy walls thicker, its cavity smaller, its powder greater far 
OF THE HEART. 
319 320 
OF T1IE MECHANISM 
than that of the right side; this ventricle is thus small that it 
may be easily filled and stimulated, and thus strong that it may 
propel all the blood of the body.—(//) Is the aorta 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, net 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 
naturally the effect of each other that they are joined ; for the 
fibres of the two hearts intermix; they are both enclosed 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 syncronous parts, (z. 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 right auricle 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. 2. 
The right 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 artery 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. , /*////,/ a/ //r 7/fP 1 / 
Vet. I 
P.5. 
N° 5 
w.e> 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, quae poenas scelerum iuebat, quando exente- 
raretur a carnifice, cor habuit singularis figurae, mucrone non 
acuto, ut fieri solet, sed bifido; ut distinct! ventriculi manifes- 
tos externa fascie apparuerint, dexter nempe et sinister, inter- 
jecto magno hiatij.”* 
OF THE PARTS OF THE HEART. 
As yet I have explained only the general plan of the circu* 
Jation, without having described those curious parts which are 
within the cavities of the heart, and which support the actions 
jn 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 venjE cav£ are two in number ;f they are named 
venai cavse 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 a great branch, 
containing the axillary arid jugular veins of the leftside, which, 
in order to reach the cava, crosses the upper part of the chest, 
and lies over the carotid arteries. The lower vena cava, or 
OF THE HEART. 
321 
* Bartholini Epist. p. 170. There are examples in the lower animals, of the 
hearts being 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 ; of which the 
No. 5 shows the right side of the heart, or the heart of the lungs opened ; while. 
jSTo- 6 shows only the left heart, or the heart of the body opened. 322 
OF T11E MECHANISM 
cava ascendens, brings in like manner all the blood from ths 
belly artd lower parts ol the nody by two great branches. One, 
marked (e,)—is the great vein which lies in the belly along 
the right side of the spine, and brings the blood from the legs, 
the pelvis, and parts of generation, the kidneys, &c.; it is 
named the vena cava abdominalis, because of its lying in 
the abdomen. Another, marked (ddd,)—arises in thrte or lour 
great branches from the liver ; it is named the branches of the 
vena cava of the liver, or the vena cava hepatic a ; and these 
two make up the lower cava; and the lower and the upper cavas 
now join themselves at (e,)—to form the right sinus of the heart. 
2. The right biNUs of the heart, marked (e,) is of con- 
siderable exteut; it is just the gradual dilatation of the two 
veins forming the auriclt 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 fibres, which make very 
deep risings and furrows upon the 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 onetime 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. 
323 
Lower! we can find nothing but on the inside or the natural 
angle of the two veins, and on the outside some fat cushioned 
up in that angle in the line (i.) Though generally wanting, I 
have found the tuberculum Loweri very distinct in the hu- 
man heart. 
4. fhe auricle is, as I have said a small appendix to the 
great bag or sinus, and is marked (y!) It is small, semi-circu- 
lar, notched or scolloped, and somewhat like a dogs 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. 'Fhe point chiefly to be noted is this, 
that the veins, as they approach the auricle, are thin, delicate 
transparent; that where they expand into the sinus they be- 
come fleshy, thick and strong; that in the auricle itself the 
muscular fibres at (jf) 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(y') are what are named the 
musculi pectinati auriculae. 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 (z,) 
where the auricle enters into the ventricle, and the valves are 
marked (*,) and how necessary these are for regulating the 
AURICULAR VALVES. 
W8. 
K° 7. 
Aubiculati Valves explained. 
Fig. 7. shows the Auricle and Ventricle cut open, and the valve hanging in 
three great divisions —(a) Fart of the inside of the Auricle.—(h) Part of the in- 
side of the Ventricle.—(c) The tendinous Circle from which the membrane of the 
valve arises.— The Column® Carnae.—(e) The Cord® Tendine*.—{fjf) The 
th.ree great divisions of the Valve—Vo. 8 shows the circle of the entrance of the 
Auricle still entire ; where—(_§■)—marks the entrance into the Auricle.—(fff) 
The three divisions of the Valve.—(d) the Column® Carncse and (<?) The Cor- 
el Tendin*. 324 
OK THE MECHANISM 
tnovements of the heart will be easily understood by consi- 
dering the conditions in which the auricle and ventricle act. 
First the cavas 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, which 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 foetus (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 
are actually tied to the inside of the ventricle by many strings, 
which being, like the valves, of a tendinous nature, are called 
cordjE tendinEjE, or tendinous cords ; and these cords being 
attached to little processes projecting from the muscular sub- 
stance of the heart, these processes are named columns 
cARNEjE, 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; or they are named val- 
vul/E TRtcusriDES, or three*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 (//) 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- 
as labour, violent struggles, &c, which send the blood 
too quickly upon the heart; while the left auricle and ven- 
tricle, on the other hand, can never be over loaded, as long 
as the pulrponic artery preserves 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 fleshv 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 ; ail of them have perfect con- 
tractile power, and are indeed the 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 
thinner, the fleshy columns smaller, the cavity greater, than 
those of the left side; the right ventricle of the heart has also 
a peculiar form for the septum cordis, a partition betwixt 
the right and left heart, is not, as generally supposed, a part 
common to both; but the left ventricle is much longer and 
more conical than the right one; the septum belongs almost 
entirely to the left ventricle ; the right ventricle which is much 
bigger, laxer, flatter, and thinner in the walls, is, as it were, 
wrapped round the left; and thus the left ventricle alone 
forms the 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, irregular, and crossed with columnse carnete 
while a smooth and even lubricated channel marked (wz) 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 
the auricle pours it in ; the artery 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 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 (;i)—-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, becomes so tense as to do the office of a 
ligament: these are called the semilunar or sigmoid 
VALVES. 
Now the condition 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 tendinete 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 auricle 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,  . 
oJ/rfr/ 
Jlefireeentinq the Back /tort of the Hr art The great t'rnneuy Vein The 
Shei/ie of the Auricle', and the entrance of the Pulmonary Veins 
n:9 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 monste. s, 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 
iorm ; 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 view of the heart; 
but I have here added a plan of the back part of the heart,* 
showing, 1. How the left ventricle lies behind ; 2. How the 
left aur cle 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 pulmonic 
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—('oo) the two pulmonic veins 
entering from each side of the lungs—(/>/>) the opening of 
these into the auricle—(yy) 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 auricl* are seen heref 
(5^:)—Now it is to be remembered that the left auricle is 
* Explanation of the back view of the heaiit, 9. No. of Plate 7. 
1. The left Ventricle—‘2, The left Auricle—3 3 3 3, The four Pulmonic Veins 
—4 4, The two great branches of the Pulmonic Artery—5, The Aorta—6. The 
Carotids and Subelavians—7, The Cava Descendens—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 
follows the plan. No. 6. OF THE MECH VNISM 
328 
smaller than the right, that the circle or opening of the left 
auricle is of course smaller than that of the right ; ir.it bile 
it requires a valve divided into three points to till 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, 
and is also the reason of the valve of the right side being 
called tricuspid or three-pointed, while this of the 1 it side, 
from some very slight resemblance to a mitre, is named 
valvula mitralxs, the mitral valve. In 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 columns carneae and tendinous 
strings to support it; the same rough irregular surface towards 
the opening of the auricle; the same smooth gutter leading 
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 columns 
carneae, and much thicker in its fleshy walls, as at (tt) 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 (if)—-where manifestly the general struc- 
ture, and general intention of the valves are the same as in 
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 peculiarlv 
guarded by three small hard tubercles, which being placed 
one on the apex or point of each valve, meet together wdien 
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 Corpor \ 
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 swelling, 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 ©f 
the aorta. OP THE HEART. 
329 
No. 10. 
No. 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 (bb) the carotids 
and subclavians—(c) 
Show one of the co- 
ronary arteries or ar- 
tery of the heart.—■ 
(d) A part of the 
Avails of tl)e heart.—• 
(eee) The three valves 
stuffed and turgid to- 
wards the heart.-—3 
No. 11. 
No. 11 shows the 
lower part of the aor- 
ta cut open, and two 
of the valves—(aa) 
entire ; and the third 
valve—(bb)—cut in 
two by slitting up the 
artery.- And (rr) 
shows the mouths of 
the two coronary ar- 
teries. 
No. 12 shows the 
aorta slit only in its 
lower part, 'and the 
valves (aa) and the 
mouths of the coro- 
nary arteries (bb) are 
seen in their natural 
situation.—N. B. In 
these two last draw- 
ings the corpora se- 
samoideaare distinct- 
ly seen in the central 
part of the edge of 
each valve, and they 
need no letter to dis- 
tinguish them. 
No. 12. 330 
OF TUB MECHANISM 
OF THE CORONARY VESSELS. 
But there still remains to be explained that peculiar circu- 
lation by which the heart itself is nourished, and yet there is 
nothing in it very different from ihe usual form of arteries and 
veins; it is a part ol the general circulation of the body, for 
the heart is nourished by the two first branches w hich 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 und< r the valves of the aorta, while the veins 
end with one great mouth in the right auricle. 1 he coronary 
arteries are tv o 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 rig;it: 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 dov n 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 gn ove 
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 belong 
as peculiarly to the left side of the heart as the other does to 
the right side: after supplying the left ventricle, &c. it turns 
over the point of the heart to meet the extremity of the first,, 
and inosculate with 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 gr at arteri s, constituting the vasa vaso- 
RUM, as such minute branches sent to vessels are called. 
The great co onary vein which collects the bl od of 
these arteries, arises in smalt 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 it own peculiar 
route. Whi n the trunk of the great coronary vein (accom- 
panied by several lesser veins) arrives at the auricle, it runs in, OP THE HEART. 
331 
between the left auricle and left ventricle ; it turns all round 
the uack o> the auricle till it gets to the right side of the 
heart; it ties 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 right 
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, &c. are all but branches of the great coronary vein 
running along the right side or lower surf ace of the heart; if 
there were to he 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 tlreir obliquity performs the office of a valve. 
This name of coronary vessels is a very favourite one with 
anatomists, and is appii d wherever vessels surround the parts 
which they belong to, however little this encircling may be 
like a crown ; and it is thus 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 he 
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 lie as it will, 
if the condition of the aorta be considered, it will he 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 instantaneculv follows that of the 
heart, but its contraction is riot, like that of the heart, such 332 
OF THE MECHANISM 
as to bring its sides together; ou the contrary, the aorta is 
full when the heart strikes, the action of the heart distends it 
to the greatest degree, the aorta re-acts so as to free itself ot 
this distention, but still it remains in some degree full of blood ; 
else how could this, like every other artery, preserve always 
its foi*m and apparent size ? In this condition of matters, it is 
obvious that the coronary branches are on the same looting 
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 ot 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 v'hat doctrine is there w'hjch such clumsy anatomy 
and awkward injections may not be made to prove ? They 
used mercury, tepid wrater, 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 ; ot the pluera 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 bod)'; 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 thb 
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 
which was tied up in the coronary arteries and veins exude 
upon the inner surface of the heart, but with no effect; *7' 
* p , y** I'd/’ C / 1 ' 
Petff’tfly //if ( It h/ftc/tUfft Ict/cf . 
Iran/ the Heart aha l 'hiId 
about S erst i/cars aid. 
N?13 
ix.^4part of the .Lungs, 1>.1>. the hcricardium by which the Heart is sus- 
pended, c.c, the Ventricles of the.Heart. d.d. the Aorta encircled Ip the 
Herteardium. e.e.e.e. the Subclavian and Carotid Arteries, g. the pendulous 
part of'tl/e /tiffh t. 'tiincle, li .the Cm/a deseendens ip which the Heart is in 
part suspended, t.i, the Cara asrendens with a pencil passed up into the 
I'ir/ht Auricle, this pencil is behind the hdtsfachtan ITih'e, the Austachian 
f/ilne itself is rnarhed lc, the little J’alvr ofthe Coronary THn which is con- 
nected with if is n/arhed m. OF THE HEART. 
333 
Oil 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 1 hebesius and V eus- 
sens describe, then the blood flowing all by these shorter and 
easier passages, none could come fo the great coronary vein $ 
its office would be annihilated; and itself, contracting gradu- 
ally7, would soon cease to exist. 
OF THE EUSTACHIAN VALVE. 
There remains to be explained in the mechanism of the 
heart one point; and which 1 have separated from the others ; 
hot because it is the h ast important, but because it is the 
most difficult, 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 hud been easily described, should 
have been first described : for it is a valve w hich lies in the 
mouth of the lower cava, just where that vein enters the right 
auricle of the :.eart. How imperfect a valve this is, how 
difficult to dissect or explain, may easily be known from 
this, that Winslow was first incited to look for the valve by 
some hints in Sylvius : he was soon alter fairiy 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 aii 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 Eust ac hi an a, a name which it has retained to this 
day, andheadded hev.ticularis, 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, artd 
its place just over the mouth of the cava seems to point out 
that use which Luncisi 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 lrom the liver and low'cr 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 ol the isthmus, as it is called, or edge of the oval hole ; 
its anterior horn arises from the vena cava, w here 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 foraminis ovalis: these two 
pillars were called isthmus VieusSenii, and by Haller are 
named annulis foss,£ 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 betwixt 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 
white 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 OF THE HEART. 
335 
feetus and the use of the oval hole. Winslow first began about 
eighty years ago to observe the connexions and uses of this 
valve ; he laid it down as an absolute fact that this valve was 
almost peculiar to the feetus ; 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 he found : it is 
also incredible what absurd consequences arose from this doc- 
trine, which, after all, is but a dTeam, 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 feetus, they conceived the follow- 
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 mother’s 
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 of fresh blood was directed by the Eus- 
tachian valve into the oval hole, through that into the left auri- 
cle and ventricle, and from these directly into the aorta and 
carotids; while the foul blood of the upper cava went down 
into the light 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 feetus, joins the aorta only as it goes down 
the back, and none of its blood can pass upwards into the head. 
This is the peurile 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 Sahbatier; 
and Haller, after announcing a theory not at all differing from 
* One author, I find -in the Acta Yindobonensia, is exceedingly angrv indeed 
with all the great anatomists, for not connecting more strictly with each other, the 
anatomy and accidents of the foramen ovale, and Eustachian valve; with Mor- 
gani, Albinus, and Wiedbriecht, he is offended for saying that they liar! seen the 
foramen ovale open, without saying one word concerning the state of this valve; 
and with Lieutaud Portal, and others again, he is equally offended that they 
should have had opportunities of seeing the Eustachian valve entire without in- 
quiring into the condition of the ova! hole. The reason of all this is very plain; 
the oval hole had not been open, neither in the one situation nor in the other, else 
it is very unlikely that such correct and anxious anatomists should have described 
that valve which arises from one of the borders of the oval hole, wiihout observ- 
ing it open, if it was so ; especially as the oval hole, being open, is by no means 
an unusual occurrence. this, challenges it as his own theory ; “ hanc meam conjectu- 
ral etiam a Nichols video proporii.” Ot the truth of this 
theory Haller was so entirely satisfied, that he not only pub- 
lished u as peculiar! his own, but reclaimed it when he thought 
it in danger of being thus appropriated, by another. Sabbatier 
is uie last in the tram of autiiors ; 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 
foetus, and that there 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 all that Winslow, 
Haller, Sabbatier, and a mob of others, have been able to say 
in proof of the connexion of the Eustachian valve with the 
circulation of the fetus. 
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 affect ihe 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 
theorizing 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 fetus ; that it has no connexion 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 vense cavse is imperfect; 
the anterior part of the auricle chiefly is muscular, and when it 
contracts, the laxity of the cavas and the great width of the sinus 
336 
OF THE MECHANISM ->/)A/ //.) of the (' U'ifac/ua-n Va/vr . 
NTl J. 
NT 15 OF THE HEART. 
337 
Venosus, (z. 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 recticu- 
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 he 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 which 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.”* 
* Eustachiax Valve. 
No. 14. explains merely the place ol the Eustachian valve, which is seen at (m) 
—No. 15. explains both the place of the valve and its relation to the oval hole (e) 
—'behind it, the mouth of the ventricle (n)—which lies before it. 
In both these plans—(a) Is the cava decendens—(b) The aorta rising behind it 
--(cc) The back of the auricle slit open-—(d) The cava ascendens, in the mouth 
ot which the valve is—(e) The foramen ovale {ff) Its two rising borders, named 
pillars, isthmus of Vieussens, annulus ovalis, &c.—-{?n) The Eustachian valve, of 
which the two cornua, or sharp points are seen on the lower plate, terminating in 
the pillars of the foramen ovale on one hand, and in the walls of the auricle 
on the other. 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. explains more particularly the uses of the valve. Some authors con- 
ceived that it directed the blood rising in the line (o)—upwards into the oval hole : 
others that it directed the column of blood, represented by the arrow (p)—into 
the right ventricle ; others that it protected the column (o)—from the weight of 
the column (/j.)—I rather suppose that it completes the auricle in the direction 
of the dotted line £7)—and so strengthens its action. 338 
OF THE ACTION 
OF THE IRRITABILITY AND ACTION OF THE HEART 
But even this curious mechanism of the heart is not more 
wonderful 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 ; 
lor 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 j 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 also could accomplish nothing. 
* Thickening the walls of the heart by vinegar, strong acids, alum, or boiling 
the heart, have assisted us in unravelling its structure but very little. OF THE HEART. 
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 we 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 external surface ; for if instead of cutting 
out the heart, we leave it connected with the body, seek out 
(as the old anatomists were wont to 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 alter 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 ACTIOS 
of their heart; a Newt’s or a Toad’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 head 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 il 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 the most 
irritable muscle of the body, if all this irritability arise from 
the nerves, how can it he 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 alternate 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 his 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 tartarso that everv suc- 
cessive drop of blood which tell into the ventricle swelled and 
puffed up so suddenly as to distend the heart, and then burst 
out by the aorta. Philosophers have heen so bewitched with 
the desire of explaining the phenomena of the human body, 
but without diligence enough to study its structure, that from 
Aristotle to Buffon, 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 palsative 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 power. 
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 ACTIOK 
roused 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 the 
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, (luring 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 twist with the force of the blood driven into it, and 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 with 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 difficulty 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, the lungs are not moved by any 
diaphragm; and 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 
OF THE HEABT. 
343 344 
OF THE ACTION OF THE HEART. 
itself into the spine behind. It is on the left side of this 
membrane 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 (b)—or what we usually call the forepart of the heart, 
is remarkable 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 right side ; the apex (<i)— 
or acute point is turned forwards and a little obliquely towards 
the left side, where it strikes the ribs; the vena cava(e)— 
enters in such a manner through a tendinous ring of the 
diaphragm,! that it ties down the right auricle to that floor 
(as I may term it) of the thorax; the aorta (J") 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 the 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, hut 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,(g-)—just as we hook the fore fingers of 
our two hands within one another. The right heart (AA)— 
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 Q>*)—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 
(£)—is seen only in its very tip or extremity, where it lies just 
behind the pulmonic artery : and the aorta (f)—arises from 
the very centre ot 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 tor us to conceive, no one part having that 
relation to any other part which we should beforehand sup- 
pose. 
* The true position of the heart is what is represented in Jfo. 10 and IT; where 
No. 16 shows the heart set upright, as I have hitherto represented it irwall my 
plans, while No. 17 represents its inclined position lying almost horizontally upon 
the floor of the diaphragm. 
f Let it be observed, that (e) in this drawing, marks the point where the lower 
cava was tied close upon the diaphragm, to prevent the injection going down into 
the veins of the liver and abdominal c-av®. *VJ- ’ z7 •* 
'//V /<//<',! 
de/nonstrati/ip the trrtfjrosititm of PceJZiart. 
N° L(> 
x° 17 
T.Bc/l chi. P. Mayer irk it. oJ/tr/r/fj **> 
of the Pcricartliu-ni of which \ IH is u true tlrawiny "N" 19 a Plan 
she wi.ruj r/s > uihjiuu over the Heart 
IP. I. 
P. u> 
Puri <•/' (he Lu. nys 
Part ofrfte Limy* 
n:i8 
XV19 OF THE PERICARDIUM. 
345 
OF THE PERICARDIUM. 
Bat the pericardium, parse, or capsule, in which the 
heart is contained, affects and regulates its posture, and makes 
the last important point concerning the anatomy oi 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 the pericardium, the heart is quite empty and re- 
laxed i but I believe it to surround tn 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 lav it 
open with a probe and lancet without wounding the heart; 
and still f urther, 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, whi h 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- 
tefy, surrounding these in one greater loop : 4thlv, 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. 1. PI. 12. 346 
OF THE PERICARDIUM. 
heres to the upper surface of the liver. Thus it happens that 
the liver anil 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 cornua, 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 
heart itself. I have marked the manner of this more delicate 
inflection of the pericardium at (aa,)—where the pericardium 
is loose : at (bb,)—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 thickhess 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 bv its 
connexions with other parts, especially by its connexions 
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 OF THE PERICARDIUM. 
347 
receiving the blood which came from the rapture, has dilated 
in such a manner as to receive nine or ten pounds of blood, 
but has 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,orthe 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 w ater 
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 Bar'tholine, 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 ple ura 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 
pericardium is that you find water there whenever at any time 
* They are thus denominated in all the charters of the College of Physicians 
from the time of Henry VIII downwards 
t The shocking indecencies of their reasonings on this subject I will not con- 
descend to draw out from the obscurity of that "barbarous idiom in which it was. 348 
OF THE PERICARDIUM. 
you find it in any of the other cavities of the body. If a per- 
son have laboured under a continued weakness, or have been 
long diseased, if a person have lain long on his death-bed, if the 
body have been long kept after death, there is both a conden- 
sation of the natural halitus in all the parts of the body, and an 
exudation of thin lymph from every vessel; there js water 
found in every cavity, from the ventricles of the brain to the 
cavity of the ankle-joint, and so in the pericardium among the 
rest. But if you open any living animal, as a Dog, or ii 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. W hen 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 it 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 •he 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 the vessels endangered, by shocks and falls, 
it is awful to think. The pericardium is no doubt some re- 
straint: its connexions with the diaphragm and with the me- 
diastinum, make it a provision, in some degree, against any 
violent shock ; its internal lubricity is, at the same time, a 
means of making the heart’s motions more free ; yet the heart 
roils 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 hack into the chest, so that its pulse is no where to 
he 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 depressed again when 
the child is delivered, or the waters of a dropsy drawn off. It 
is shaken by coughing, laughing, sneezing, and every violent 
effort of the thorax. By matter collected within the thorax it 
delivered : “ Sed non cogar hue me conferre. Fateor enim nativam Christi tem- 
periem nihil pravorum liumonun produxisse, quia perfectissima; at a causis ex- 
tends, vig-iliis, cruciatibus, itineribus, vulneribus et mille tornientis quid non pra- 
ter consuetam nature divin® perfectionem produetum crediinus ? Ad hsec sano 
sensu id accipiendum, nihil pravorum humorum in corpore Christi generatuno.” 
Bartholini Epistolce, p. 299 —“ Idque de Salvatore innoxie dixeris, quern seimus 
manducasse, bibisse, dormivisse, ambulasse, et quid non egisse, ut se hominem 
cunctis actionibus, qua; secundum natnram sunt, submitteret ; sputum emisit, 
quum luto misceret ad curandum eojeum, et sudavit ingruente martyrio, et sine 
dubio non parum seri in thorace col legit, quod, aperto post mortem latere, emana- 
vit.'’ Bartholini Epistola, p. S00, OF THE PERICARDIUM 
349 
may be displaced to any degree. Dr. Farquharson cured a 
fine boy, about eight years old, ot a great collection oi 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 ol 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 hands 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 could 
not happen merely from 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 extremely 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 which supplies the 
body j 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 bodv, 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, where it is purified and renewed; 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 
as to give a sense of fulness and tension to the vessels : the 350 
OF 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 “ ultinium 
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 re- 
mains of life in the right side, after all appearance of life on 
the left side its 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 halt 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 co- 
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 ; “ Whenever 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 fud ot (flood, 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 was 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 during the night. 
These things next explain to us why they called the right 
ventricle ventriculus sanguineus ; they found it full ot 
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 because 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 arteria 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- 352 
OF THE HEART. 
hies ; that is spurted out, and was full of animal spirits ; and 
thus it became easv tor them to show how sate 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 lite : and this they considered as such an awtul 
difference, that when arteriotomy in the temple was first pro- 
posed, they pronounced it murderous, and on this reasoning 
it was absolutely forsaken tor many ages. 
But the oldest of our modern physicians soon tound a ne- 
cessity of mixing this blood and animal spirits together, and 
for a long wiiile could hit on no convenient way by which 
this mixture might be effected ; as a last shitt, they made the 
blood exude through the septum of the heart; and then the 
current doctrine was, that ot the blood which came from the 
liver, one halt 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. Rioianus 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, Rioianus, Gassendus 
and many others, saw, the necessity ot having side passages 
through the septum ot the heart. I really believe frorv their 
mean equivocating manner ot talking about these passages, 
that they had never believed them themselves.* u 1 he 
chyle,” says Barthoiine, “ and the thinner blood, passes 
through the septum ot the heart, when the heart is in systole 
and the pores and passages are enlarged.” Thus did the 
celebrated Barthoiine believe the septum perforated. Wal- 
Iseus, 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,” say’s 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 oi 
the mind were deduced from the physical properties of the 
» That I may npt seem to speak too harshly of this knot of conspirators against 
Harvey, \ will quote what Boerhaave says of lliolanus, who was at the head ot 
them ; “ Non ipse callidus cavillationum artifex Rioianus,” ike. 
■j- Experimento perforatum ostendit Broadbecquius 1 ubingae. OF THE HEART. 
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, we 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 surprised when he finds the contrary; 
w Cor vastus fuit homo, tamen audax fuerat, ut cicatrices in 
capite frequentes et rimse in cranio testabantur.” But if Bar- 
tholine be right, Kirkringius is quite wrong, and has mistaken 
the doctrine ; for he says, “ An magnanima fuerit hsec magni 
cordis foemina, nescio,” &c. u 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 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 how 
the Messinians, that unhappy people, who lived for so many 
ages the slaves or helots of Greece, lost their great 
general Aristomenes. But how great he was, never, accord- 
ing to Pliny, come to be known till after his death; for the 
Lacedemonians having catched him three times, 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 had 
not been made since then a hundred times. w There was a 
robber, (says Benivinius,) one Jacobus, who having been taken 
down from the gibbet apparently dead, but really having in 
him the remains of life, was laid carefully, recovered, was- 
353 354 
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 piiis) 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 twro-legged vein 
carrying the atrabilis, the source, no doubt, of all his inordi- 
nate cravings, directly into the 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 
the anatomists of that time knew very well was the seat of 
memory) was in him so small that it could hardly contain a 
spoonful of that kind of brain ; and this want was the reason 
(having so little memory) that he was so persevering a thief; 
for let you whip him, banish him, clap him in the stocks, he 
forgot it straightway, and was back at his old tricks again, like 
a dog to his vomit.* 
But these are now almost forgotten, though perhaps the 
history of the absurdities of the human genius should no more 
be neglected than of its beauties. Is it not delightful to feel, 
that after floating in this ocean of conjecture, after all these 
disorderly and wild dreams, we are come to have an idea of 
the heart, simple and beautiful; of a heart containing within 
itself two functions ; first, the office of renewing the blood ; 
secondly, the office of animating the arteries, and by them 
preserving in life and action the whole system of the body? 
These are the two offices which I shall now proceed to 
explain. 
* “ Non videntur silentio esse praetereunda, qua; nuper in inciso Jacobi cujusdam 
furis insignis cadavere annotavimus ; bifurcatam scilicet venam quae a liene ad ven- 
triculum atram defert bilem, turn et abscessum in sinistro cordis ventre pituita re- 
dundantem ; postremo et posteriorem ejus capitis partem, ubi memorise sedes est, 
adeo brevem, ut tantillam cerebri portiunculam contineret. Qaam ob causam, 
curn priornm scelerum et eorum qua; pro his sa;pe passus fuerat. tormenta scilicet, 
exilia et carceres minime recoi-daretur, toties ad vomitum tanquam canis impu- 
dens reversus est, at in laqueum tandem incident, vit*que ac furti fineru tecerit,’ 
—Vid. Jienevinius. 355 
CHAP. II. 
ON THE APPEARANCE AND PROPERTIES OF THE BLOOD, ON 
THE CHEMISTRY OF OUR FLUIDS, AND ON THE INFLUENCE 
WHICH 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 w7as 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 had 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; w'hile philosophers of les,§ 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 wrays by which these motions and secretions 
might be explained. They then began to estimate the calibres 356 
OP 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 connexion 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 hydraulics, (*. 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 KeiU, 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 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 foetus; 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 the 
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 down 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 iourth 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 made one red 
globule. 
l'o 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 lor 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 oft, 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 tegular 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 wrong 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 inflammation, fevers, 
deeper obstructions : and from such causes, or from the break- 
ing down of the blood 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 w'e are moreover 
certain from the observations of that most accurate and curious 
observer of the minima natune, that there are innumerable OF THE BLOOD. 
358 
vessels of such a smallness that none of these globules could 
pass; so that it is necessary to suppose inferior classes ot 
globules of the fourth, fifth, sixth, and other orders.—Whence 
by analogy we are to conceive globules of the third order made 
up of six globules of the fourth order, and these of six ot 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 doc- 
trine made it easy for every particle to pass every vessel; but, 
alas! it leaves no room for that old catchword of the system, 
the error loci, nor any provision for making diseases. 
How all the physicians in Europe could dig st 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, whose 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 stepsof stairs ? In all his mathematics, I do 
not believe that Martin could find any contrivance fit to help 
him out of these difficulties. Martin observes, in his own tvay 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 itand then he wonders 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 
abeautiful harmony and regularity 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- 
soh supposed that the lymphatic glands, which seem at first to OF THE BLOOD. 
359 
he mere convoluted vessels, but which being injected with 
mercury, and cut into, are seen to consist of numerous cells, 
form in these cells the primordia 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 vessicle 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 round 
particles in the lymph, and often he finds the lymphatics full 
of red blood. 
Next, he 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 milkv 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 globules 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 chyle, 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, how 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 
occurrence, and quite intelligible. There are not found an) 
where, not even in the spleen, imperfect globules advancing m 
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 ; it 
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 organ- 
izing 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 fetus, 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.'1 
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 othei 
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 
we have seen this simple and beautiful subject of the blood 
tortured through ail 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 prevents 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- 
nexion or sympathy it may have with the diseased state of 
the artery.” u 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.” Connexions, and 
unknown sympathies, and living powers in fluids, and energies, 
and efforts, and intentions, and u 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 u 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 fcetus 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 the theory were once established, there would 362 
0F THE BLOOD; 
remain nothing to be done in all the animal body but what 
was done by the blood ; nothing to wonder 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 ; 
lie tells us that this blood forms the vessels in which 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, which 
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 the 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, irritrievable, 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, or extrava- 
sated in aneurismal sacs l* 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 so5 
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 the most recent inquiries no jelly appears to be in the blood, C, B. OF THE BLOOD. 
363 
has 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 perlect crea- 
ture, is affected by cold first. In page 79, we are informed, 
that a fresh egg, in consequence of being alive, resists ihe 
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, showing no 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 k will thaw again, and yet congeal at its proper time; and 
he tells us, that he 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 has 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 by 
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 j 
and I am come to look on a suite of experiments as coolly as 
upon a set of neat plans and figures by which the author 
chooses to illustrate his hypothesis. 
That this coagulum, 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 the 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; u When new vessels are formed, they are 
not always 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 privil ge of knowing whtn it should exei t itselt thus, 
is really wondertul; that it should have some kind of intelli- 
gence, or consciousness, by means ot which it could under- 
stand when it were within and when 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 phenomenon 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 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 graft 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 w ho 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 w ill not unite. Prove to me only that 
fresh cut parts are not alive, and cannot naturally unite with- 
out the assistance ol some foreign power, and then I will 
acknow ledge w illingly that they are altogether beholden to the 
inter ediation 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,tc that mortification 
immediately follows here the circulation is cut offlor this 
proves mcreiy, 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 taking 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 
iniil and the plough are dead the moment that the horse is 
gone or the tv ater fails. 
Lastly, we are told “ that it is by the contiguous sympathy 
of the blood and body both being alive,5’ 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 continual}’ impregnated with air, that it 
is neither its original constitution, nor these presumed sympa- 
thies that make tt 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 fluid should 
be endowed with life. A fluid is a body whose particles often 
are not nomogeneous, have no stable connexion 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 ? It is 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 n-o proof that oxygen is absorbed in respiration, but only carbon re- 
moved. 366 
OF THE BLOOD, 
plied with chyle, and now starved of its usual supply ? Is it not 
lost in astonishing quantities in haemorrhages, 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 aciions 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 ? 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 ceco- 
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 which 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 vita; diffuse, which he announces thus : 
“ I would consider that something similar to the substance 
of the brain is diffused through the body, and even contained 
m the blood ; and between this (viz. the matter diffused in the 
blood) and the brain the communication is kept up by nerves.” OF THE BLOOD. 
367 
This matter he does not like to define, but he 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 vitae 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 connexion 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 vitae 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 diffused 
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- 
row view, not merely of this but of higher subjects. 
Plants have active and irritable fibres ; by the most curious 
actions they drink in water; water alone they can convert, by 
the most simple mechanism, into most delicate perfumes, into 
delicious fruits, or into terrible poisons. w 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 j” 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 know 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. 
f Notwithstanding the force of this criticism, which is too valuable not to be left 
on record, the doctrine of the life of the blood is in my mind the best established 
doctrine of modern physiology. C. B, 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 the heart or 
at the centre of the circulation different from what it is in the 
glands, excretories, and all the extremities 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 
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 colourness insects, there seems 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 the 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 BL001>. 
369 
they are bigger then in a grown animal; and though Leeuwen- 
hoek thought is 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 some 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 when they come into nar- 
row passages, and expand again when they get into wider arte- 
ries. This Reichell says he has seen, and Biumenbach be- 
lieves ; but Biumenbach, 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 ©?. 370 
OP THE BLOOD. 
mucus : that lenticular or oval form which authors speak of, £ 
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 w ater 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 rxercise 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, arc 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; wc 
cannot but be conscious that this peculiarity is not yet ex- 
plained. * 
According to Berzelius, about one fourth of the dry colouring matter is osyde 
ot iron. 3 OE THE BLOOD. 
371 
COAGULABLE LYMPH. - 
The coagulable part, the cake which is felt when we wash 
away he red globules, that which has been called the gluten, 
and now bv 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 hone : 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 aikaline 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 phos- 
phate of iime, or, in other words, the earth of bones. 
Its peculiar properties, as ic 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 giuten, and no anal- 
ysis of any single part has ever disappointed us. A muscle 
being squeezed, and thoroughly cleansed of blood, washed in 
spirits if wine, and again cleaned, is seen plainly to be hut 
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 
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 \ oured out be- 
twixt 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, res- 
tores 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, 1 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 nour- 
ishment 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, 
although 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 sacch- 
arine or extractive matter, belonging to vegetables, and some 
proportion of the oxalic,v malic, or other vegetable ac ids.* 
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 
tlvan that which makes it boil; being dropped into hot water 
it coagulates as it fails ; 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 hitherto found in it. C. 13. OF THE BLOOD. 
373 
what remains fluid is the serosity. On cooling, the serosity 
©oagulates like size or jelly. This coagulation arises from the 
gelatin dissolved in the water : and this gelatin may be preci- 
pitated by various re-ageuts, but especially by tanin, and by 
alcohol. After the separation of the gelatin, there 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 with salts ; observe how little 
saliva differs from the serum ; observe how perfectly the serum 
resembles milk, since mixing serum with water produces a 
milky fluid, that is, a fluid which 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 enteresting 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 chemistry 
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 without 
* With the exception of the water of dropsies, all the fluids mentioned here 
Save been found very different from serum. 374 
OP THE BLOOD. 
hope, that by this science, all others, and ours in an especial 
manner, ma) be improved : lor the action ot 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 ol 
the materia medica: and among hundreds of medicinal plants 
which they h.id thus analysed, they could find no variety ol 
principles, nor any other variety of parts, and names than those 
of phlegm, and oil, and alkali, and acid, and sulphur, and 
coal. By this they dishurthened their consciences of all they 
knew, pleased their scholars, and set the physicians to work, 
forming magnificient theories ot salts, sulphurs, and oils ; for 
such has ever been the connexion 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 bodies. They could know nothing of the 
aerial forms of bodies, for they allowed these parts to escape. 
When their subjects by extreme force 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. WThen they thus 
stopped at airs, they stopped where only the r analysis became 
enteresting or simple ; stopping where they stopped, among 
their oils and sulphurs, they made their science a mere rhap- 
sody of words. 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 
anv 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 OF 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. W hen 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 ail the science, it is, easy to explain ; for chemistry, ever 
since it has been a science, has rested upon one single points 
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 dre, the combustion of inflam- 
mable bodies, the respiration of animals, the calcination of me- 
tals; and w'hatever theory explains one explains the 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 f rmer 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 breath- 
ing, loaded, as they supposed, with the inflammable principle. 
When they calcined a metal, (which is done merely by heat- 
ing the metal <nd exposing it to air,) they found, as in these 
other operations, the air contaminated, the metal losing ite 
metallic lustre, ductility, and all the marks of a metal,—ac- 
quiring (in certain examples) new qualities, like those of some 
mineral 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- c of an inflammable principle to the air ; and 
to say concerning r spiration, that it was the business of the 
ai< to take a ntinually 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 los3 
of its inflammable principle it should not lose in w tight, 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 phlogiston, 
or inflammable principle, was added to the calx of any metal, 
as to red lead, by roasting it with any inflammable body— 
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, &c. 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 
present 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 metallic 
lustre, the upper part of it assumes first a yellow and then a 
red colour, small red particles are seen floating on the surface 
of the mercury; and these are the mercurius precipitatus 
per se, a most acrid calx of mercury. If, first, vou estimate 
how much air has been expended during the process, you 
find that the weight of the mercury is increased in exact pro- 
portion ; 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 metallic qualities and lustre in propor- 
tion as the air is expelled, In short, wre find the metal hea- 
vier when combined with air, lighter when the air is driven OF THE BLOOD. 
377 
out; we find it having the qualities of a mental 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 ; their 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 ; with animal and vegetable life; with 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 w’as 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, 
wdiich at least we have hitherto conceived to be pure ? 
Yet if there be one tvord 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 every 
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 them by absorbing the basis of pure air; for pure 
air is nothing but this presumed basis dilated into the form of 
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 their essential 
points the same, viz. a change of qualities and a production of 
heat in consequence of the absorption of pure air. 378 
OF THE BLOOD. 
First, when an inflammable body is burnt or consumed by 
lire, the basis of pure air is combining with the conbustible 
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 w’asted ; the inflammable body burns and seems 
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 cf 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, 
which 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 basins, and poured from dish 
to dish. Combustion, than, in 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 pow'ers. 
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 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 of lead you 
have 110 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 distil 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 
* Twenty one by weight of oxygene. OF THE BLOOD. 
379 
now combined with heat, it appears in the form of vital air: 
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 calcin- 
ation 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 which 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 pro- 
cesses as these. He adds to 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 shali be sufficient to ob- 
observe 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 
pondrous 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 whole 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 was 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 
* To this doctrine numerous objections occur :—oxygene by union with hydro- 
gene forms water; sulphur by union with hydrogene forms sulphuretted hydro- 
gen e, an acid, &e, See. 380 
OF T1IE BLOQD. 
is a mere combustion, since it can be made rapid as to be 
attended with heat and flame; next we see that acidification is, 
like calcination, attended with heat and flame, and an acquisi- 
tion of weight and of properties like those of calces. We see 
some metals converted into proper acids ; acids and metals 
mixing in qualities with each other; acids and metals are both 
acidificable basis, both are capable of receiving new and simi- 
lar properties, by assuming into their composition the basis 
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, all 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 flued 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 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.:}: 
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 connexion of respiration with the great system; but 
* It is necessary to add nitre to mate it burn. The result is not directly an 
acid, but a neutral salt formed of the arsenical acid joined to the alkali of nitre; 
■without the help of nitrous acid it is Only an oxyd or imperfect acid ; and is ne- 
cessary to use the hyper-oxygenated muriatic acid for communicating to it a suffi- 
ciency of oxygene to constitute it a perfect acid. 
f JY. B. It is necessary to enclose them in one vessel, and to pass the electric 
spark through them that they may unite. 
t Yet I must here again observe that there are no decided proofs the oxvdation 
of the blood. C. P. ct' THE BLOOD. 
381 
it is out of the body that we can best understand its particular 
effects upon the blood. 
The most obvious effect of air is its heightening 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 
atmosphere there is a large proportion of oxygene gas : if, 
l aStly, 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 id eaves 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 thro ugh 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 animal 
fluids ; but it is not oxygenated, if oil, mucilage, or mere 
water, be interposed. 
When we open a Frog, or Newt,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 hsemorrhagies in this way. 
From these facts we may understand why the blood of the 
womb, 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 strangulatons, 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 
f Carbonic acid gas is formed; the absorption of pure oxygen e is doubtful, 
f See Chap. III. 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 prevented from returning to the lungs and heart ? Are 
not tumours 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? 1’hen this first effect of oxygenation is a reddening of 
the blood. The menstrual blood, the blood of ecchymosis, (as 
in those who nave been whipt,) the blood of aneurismal bags, 
are all black ; and the blood of varices is so very black, that 
the aacients 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 
instaut that pure air is forced into the lungs, and so communi- 
cated to the blood. This stimulant power is most of ail appa- 
rent when we 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 we 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 
being united, and the creature allowed to breathe again, the 
blood becomes florid, and the heart acts. 
OF THE HEAT OF THE BLOOD. 
The next effect of oxygene is said to he 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. Oxy- 
dation 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 *'eel 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 the 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 Amphibise 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 greatest waste; 
they would, according to this theory, have lungs for crying 
with, if they pleased to cry, but by no means for distributing 
iieat. 
But in reflecting upon this most difficult of all subjects, the 384 
OF THE BLOOD. 
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 disposition of oxygene from 
the blood. It is a law of nature, to which, as far as we know, 
no exception is found, that the 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- 
tinuallypass 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, &c. for these are ail con- 
tinually absorbed, thrown oft' 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 sayr, shall this heat be regulated ? 
I sayr 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 the lungs, nor to the blood, but to the 
whole body through the medium of the blood.” 
OF THE RESPIRATION OF ANIMALS. 
The effects of oxydation 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 expo- 
sed to our atmosphere,, which is a mixed fluid very different 
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 formtd of an air which is 
most fatal to animal life, whence it has the mam e of Azotic 
Gas. Of a hundred measures of atmospheric air, w'e find 
twenty-seven only to consist of vital or pure air, that is oxv- 
gene ; seventy-two consist of azotic air, or nitrogene, as it is 
called, fatal to animal life ; and one measure only is fixed air, 
or carbonic acid, which is also an unrespirable air. But ot 
these twenty-seven parts of pure air, seventeen parts only are 
affected 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 water 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 when 
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 twro 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 ; hut the 
rapid changes of opinion, and indeed of whole systems, and the confusion into 
which the discoveries of to-day throws the result of all preceding labours, would 
almost provoke an anatomist to put out of his system the chemical discussion alto- 
gether, until the masters of that science have better arranged their materials, 
and have arrived at acknowledge*; principles 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 ox\gene taken from the atmosphere by respiration, is con- 
sumed 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 
the air respired, latent before, and now become sensible, owing to a change ot 
in the gases. 
The change produced in the blood during the circulation in the lungs, is simply 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 w hich seems so unfa- 
vourable 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 
deflagration 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 chemistry are hut a 
promise of what that science may do ; nothing of all that we 
know concerning the chemistry of the blood is either perfect 
or sure : we have our expectations still of seeing things more 
completely explained : hut 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 he 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 engineand if his 
scheme holds, they are to be fired off “ by means of the ner- 
vous electricity of Galvani !”# 
OF THE MEMBRANES OF CAVITIES, AND PARTICULARLY 
OF THE MEMBRANES OF THE THORAX.f 
Every part of an animal body, with the exception of the 
fluids, the matter of the nerves, of the muscles, and of the 
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 put in the experiments and opinions of Dr. Crauford, whose theories have been 
criticised in former editions of this work. The brief abstract of which doctrine is 
this. The venous blood has less capacity for retaining heat than arterial blood. 
When the blood of the arteries of the body is convened into purple blood, and 
enters the small veins, heat 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 superabundant carbon and when this carbon unites with n\ygene of the air 
respired, and forms carbonic acid, heat is evolved. While this action of respiration 
is producing heat, it is also forming of venous blood arterial blood. And as the 
arterial blood, in its conversion into venous blood, gave out heat, so now, being 
reconverted into arterial blood, it takes up heat, and that is not sensible beat, but 
latent. There 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 operation of the lungs. And what 
degree of heat more than necessary for the conversion of the blood, and which 
might be injurious, is expended in forming the vapour exhaled from the lungs. C. T* 
9 Vide page 23 fi. f By Charles Bell. OF THE MEMBRANES OF CAVITIES. 
bones, is resolvable into membrane by masceration and the 
contrivances of the anatomist. The fine web which supports 
the retina in the eye, and the strong cord on which the gas- 
trocnemius 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 connexions 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 measureable thickness : it 
has one surface, free or disunited, and smooth, and lubricated 
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 absorpFon; 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 
387 388 
OF THE MEMBRANES OF CAVITIES. 
any tendency to inflammation on these surfaces, they are more 
prone to adhesion than the mucous membranes, because the 
inflammatory action will more quickly convert serum to coag- 
ulable lymph (which is the medium of adhesion) than it will 
the mucous secretion. 
The mucous membrane is the continuation of the skin; it 
is every where continuous, but it admits of a natural division, 
viz. 1. The mucous lining of the lungs ; 2. The mucous lin- 
ing of the alimentary 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 hronchi, and finally, 
into the bronchial cells, an extent perhaps equal to the whole 
surface of the bodv. 
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- 
nexion. 
The second division of .the mucous membrane is the lining 
membrane of the mouth, which we trace into the oesophagus, 
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 the 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 the serous membranes from all the outward sur- OF THE PLEUIiA, 
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 costalis;) 2. then as it is reflected on the diaphragm; 
3. as it forms the septum dividing the chest ; 4. as it is 
reflected 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 ster- 
num, their interstices being filled up with the intercostal mus- 
cles. The lining membrane of course is attached in part to 
the inside of the ribs, in part to the muscular texture which 
intervenes. It is a simple membrane ; for so we call it, al- 
though like every other membrane it may be divided into 
layers of cellular membrane. On its outer surface it is most 
loose and cellular in its texture ; on the surface towards the 
cavity it is smooth and bedewed with secretion, and is conse- 
quently 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 diaphram forms the floor of division 
betwixt the cavity, of the chest and the lower cavity, the abdo- 
men. From the ribs, the membrane is reflected upon the 
diaphragm, to which it adheres ; and from the diaphragm 
and lateral parts of the chest, it is reflected to form the divi- 
sion of the chest, which is called mediastinum ; which com- 
pletes the circle of connexions, as far as relates to the lateral 
cavity of the chest. 390 
OF THE PLEURA. 
PLAN 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 njanner 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, we 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 
although 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 shows the two cavities of the thorax formed by the pleura costalis, 
and the septum or mediastinum formed by the meeting of the membranes. 
The 2d Plan shows, by the continuation of the dotted line, how the pleura 
costalis is continued into the pleura pnlmohalis. When we trace the membrane 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 tire 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 which 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 connexion of the lungs to the chest. 
The mediastinum 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 chtck; 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 the effects 
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 which, without this guard they 
would be exposed in the necessary and natural changes to 
OF THE MEDIASTINUM. 
391 392 
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 connexion 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 anterium medias- 
tinum ; 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 it scourse, 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 
important connexions-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 the name in connexion 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 
motion in respiration. How the respiration does not affect, 
the veins and cavities of the heart, will now, I trust, be easily 
conceived, and consequently the use of the mediastinum be 
understood. 
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 office of a fascia 
around the vessels, an office 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 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 connexons 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 ftom 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 for- 
ced out from them in expiration, and the regular action of the 
heart interrupted or disturbed. 
There is a further use in these connexions 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 connexion 
with the mediastinum, and by acting in opposition to the ad* 
dominal muscles. 394 
Of THE PERICARDIUM. 
OF THE PERICARDIUM. 
The pericadium, or heart purse, is the third cavity of th< 
thorax; but here again I must caution my readers on the use 
of the term cavity. The pericardium closely embraces th< 
heart, retains the lubricating fluid, and restrains and limits tht 
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 oi 
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 ex 
ternal layer bf the pericardium which is continued upon th< 
great vessels as they arise from the heart, and which form: 
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 cut of the thorax, until they reach their pro- 
per sheaths in ascending upon the neck or passing out into 
the axilla. 
a The heart, b the pericardium, cc the pleura of the right and of the left 
side, embracing the pericardium betwixt them. OF THE THYMUS ULAXJ). 
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 
trachea and carotid arteries, but it lies principally on the peri- 
cardium. It>>has two superior cornua, and two inferior, 
the right of w?ich is the longest. On puncturing this gland 
a white fluid may be expressed, and wtien we blow into this 
puncture tsfe 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 
blooi b rough the small veins. It has been supposed useful 
to fill up the thorax during the contracted state of the lungs 
in the stus ; forgetting altogether that it is large in the foetus 
and di. finishes after birth, it has been supposed to protect the 
lung= fom the pressure of the sternum ; all which are sup- 
positiois merely, that have not the most distant proof to 
support them, and vet possess not sufficient absurdity to make 
th ;m worthy to be recollected on that account. 
OF THE LUNGS. 
ie lungs are the soft compressible bodies which fill the 
t lateral cavities of the chest; and their use is to convey 
t 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 respiration. 
Respiration carries away the superfluous carbon of the 
blood, bestows heat, and stimulates ths system, endows us 396 
OF THE TRACHEA AND BRONCHI. 
with the power of speech, and affords us the sense of smelling, 
or greatly contributes to the perfection of the sense. 
In form, the lungs correspond to the cavity which contains 
them. When taken from their place and extended, they are 
wide below, forming a base, and rise conically upward; 
concave 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 
before. The lungs have a deep sulcus behi id left for the 
spine, and within the projecting lobes there is a f lace of lodge- 
ment for the pericardium and heart. 
Attending to this general form, we see why th£ lungs are 
spoken of as double, for unless by the connexion of their 
common wind-pipe there are two great lateral portions, each 
of 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 con'- ltly 
forms a lesser intermediate triangular lobe. 
OF THE TRACHEA AND BRONCHI. 
The trachea is that extent of the wind-pipe which is oe- 
twixt the larynx (already described) and the divisit of his 
tube where it is about to enter the lungs. It is seated, o' he 
forepart of the neck and anterior to the oesophagus or 5 u ■ et» 
It is covered by the thyroid gland and the flat muscle? : :ng 
from the sternum to the os hyoides and thyroid cartilage and 
all around, it has a very loose and elastic cellular merit hr'. . 
The trachea is not a perfect cylinder, it is flat on the. k 
part; it is rigid to admit of the easy passage of the air thr ;gh 
it; and this rigidity is derived from the cartilaginous h 93 
of which it is principally formed. These are not perfect!. e- 
gular: above they are most so, and are broader, and have 
weaker cornua the nearer the bifurcation : they are united by 
an intermediate ligamentous substance, which appears to be 
muscular; and these cornuse 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 ouside 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 of!' 
by the air which passes through the trachea, and the thick 
matter is 'ixpectorated. 
This secretion, which, in the healthy sta'e, 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 our of straw. And in a still later stage, it may come 
purulent, without implying lesion of surface. The firmer 
mod ales of viscid secretion, which are brought up, are proba- 
bly from the saccula laryngis. 
From its exposed situation, its sensibility and vascularity, 
the membrane of the trachea is very subject to disease. I 
hav row before me examples of general inflammation, of in- 
flan, mitory crust, of suppuration and deep ulcer in the inside 
of achea. Often lesser degrees of inflammation change 
the re of the bland secretion, making it more saline, 
acrid, a.id stimulating. Sometimes the inflammatory action 
will nix a portion of coagulablelymph with the mucus secreted, 
and hich, by this addition, will take a tubular form, as in 
the c up. But let it be remembered, that coagulable lymph 
in 1 :orm of tubes or vessels may be coughed up from the 
lung?, a consequence of blood poured into the bronchi with- 
out r e presence of inflammation. 
C entering the thorax, the trachea inclines backward, and 
pas into the posterior mediastinum, and behind the arch of 
the aorta, and before the oesophagus ; opposite to the third 
ver/ebrse of the back it divides into two branches, passing to 
t! ight and left: these, and their subdivisions, are the 
bx cnchi. 
vrhen we follow one of these tubes, we find it entering the 
3U; stance of the lungs, accompanied by blood-vessels, branches 
of ti e pulmonary artery, with their corresponding veins ; and 
l er 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. 
BRONCHIAL CELLS*. 
The bronchi ail 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. aking 
this as a question to be judged of more by the probah effect 
of the structure, than by what we can demonstrat , would 
not the air, in the supposition of its being drawn through the 
communications from cell to cell, in connexion with w ex- 
tremity of a branch of the bronchus, be more efte:n.allv 
brought into contact with the blood, than if the evtreme 
branch of the wind-pipe terminated in a cell which had one 
opening only, and which cell contracted during exp ration, 
only in a slight degree ? 
On these cells the ultimate branches of the pulmonar -te- 
ries and veins ramify and inosculate, and the thin me’ nne 
of the cell and the coats of these minute vessels do n re- 
vent the influence of the air upon the circulating blood. ly 
reader must well distinguish betwixt this regular c ar 
structure, for the admission of air which is drawn throu he 
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 t'aree 
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 c,oes 
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 difficult respi- 
ration, a ivatery effusionTakes place in the common cellular 
texture of the lungs, which effectually compresses the proper 
air cells, and after much oppression suffocates. OP THE BLOOD IN THE LUNGS. 
399 
Coloured water, or size, or oil of turpentine, being injected 
into 4 lmonary artery, returns by the pulmonic veins, Tun- 
ing i ■ vv ut is called the lesser circulation. The same fluids 
bein injected into the vein, return by the artery.* The fluid 
beii : re forcibly propelled into the pulmonary artery, 
flot the trachea, and the exudation of the fluid is facili- 
tate the action of respiration be imitated by blowing into 
th trachea at the time of the injection. These coarse expe- 
ri ents in the dead body prove little ; but the course of the 
l rod from the extreme pulmonic arteries into the veins, hav- 
mg been seen in the membranous lungs of the larcertae, the 
chemical phenomena exhibited by respiration, leave little for 
ns t ) wish further in explanation of the functions of the lungs, f 
There are some reflections which naturally occur in taking 
f this subject of respiration, which may have the fur- 
t*- ect of confirming in my reader the accurate knowledge 
t natomy. 
ough the lungs are very often found adhering to the 
i isi • )f the chest, and although this union occurs where we 
cannot discover that the person during life was subject to any 
infia unation of the chest, yet it is a preternatural appearance. 
Yii* i lgs (covered with the pleura) lie in contact; with the 
side f the chest, and consequently with the pleura costalis, 
but thout adhesion. They are passive in the motion of res- 
piradon. The muscles of respiration clothing the thorax are 
the agents in this function. The bony and cartilaginous tex- 
ture *f the thorax in the machinery put in motion, and the ef- 
fect the dilatation of the lungs ; for as the sides of the chest 
r ise, 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 
Cclij, 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 .piration the lungs are equally passive as in inspiration. 
nuscles which contract the diameters of the thorax, force 
ti mpages of bones and cartilages upon the lungs, and com- 
pr-aoing them, throw out the air by the trachea. 
COURSE OF THE BLOOD IN THE LUNGS. 
* In an experiment which was made this season by a pupil of mine, the mer- 
cury, which 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 pul- 
monary veins. 
f For the consent or sympathy of the lungs with other parts, see the observa- 
tions under the head of Par-wagnm, 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 thorax produces that suction ; or, in other word , 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 pressures of the atmosphere tl en 
causes the air to descend into the bronchial cells. 
The second circumstance which gives occasion to .miscon- 
ception, 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 lung falls 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 proximitj 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 the 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 the 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- OF THE BLOOD IN THE LUNGS. 
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 side 
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 
su focation 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 diaphragm 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 t 
401 
Fig.l* 
Fig.Z. 
First plan exhibits a section of the thorax, with the rib broken, and entering 
the ungs A. Air has already begun to accumulate in the cavity of the chest B. 
■ , eplr ,"*lnuatlt»? itself by the side of the broken rib forms the tumour on the 
d a ~hLe S6C0"d Plan exhlblts the extent of the evil. The lungs D are com- 
pressed. The cavity of the chest left by the retraction of the lungs is full of air. 
I he 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. 402 
OF THE BLOOD IN THE LUNGS. 
The emphysema of tne 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 betwixii the liga- 
ments of the lungs into the celluar texture of the mediasti- 
num, and hence up into the neck and over the body. These 
last instances are rare compared with that proceeding frf,m 
fractured rib. 
!Enu OV lHJfc. JFIKST VOLUME.