the
abner wellborn calhoun
medical library
1923
Book
presented by
THE
ANATOMY AND PHYSIOLOGY
/ t?A
OF THE
HUMAN BODY.
JOHN AND CHARLES BELL.
II
THE SEVENTH EDITION:
IN WHICH THE WHOLE IS MORE PERFECTLY SYSTEMATIZED
AND CORRECTED
BY CHARLES BELL, F.R.S.L.&E.
)
FELLOW OF THE ROYAL COLLEGE OF SURGEONS OF
LONDON AND EDINBURGH J
PROFESSOR OF PHYSIOLOGY AND SURGERY TO THE UNIVERSITY OF LONDON ;
FORMERLY PROFESSOR OF ANATOMY AND SURGERY
TO THE ROYAL COLLEGE OF SURGEONS OF LONDON ; AND
SURGEON OF THE MIDDLESEX HOSPITAL.
IN THREE VOLUMES.
VOL. I.
LONDON:
PRINTED FOR
LONGMAN, REES, ORME, BROWN, AND GREEN,
PATERNOSTER-ROW ;
AND T. CADELL, STRAND.
1829.
tfc.
*h * rf
4*
<f,U-v £ rv^t—
$ J \ ?/£ ^
London:
Printed by A. & It. Spottiswoodfc,
New-Street-Square.
THE
ANATOMY
OF
HUMAN BODY.
VOL. I.
CONTAINING
THE ANATOMY
OF
THE BONES, MUSCLES, AND JOINTS,
THE HEART AND CIRCULATION,
AND
THE LUNGS.
A 2
PREFACE
TO
THE FIRST EDITION.
I o 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
author may ever be allowed to compare his book with
others, it must be in the mechanical part j 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
useful they are in preserving the due balance between
what is amusing and what is useful; between the looser
doctrines of functions and the close demonstration of
parts. He will be sensible, how much more easily these
things can be read in the closet than taught in any
public course : he will, I think, be ready to acknow¬
ledge, that I introduce such theories only as should
connect the whole, and may be fairly distinguished as
the physiology of facts ; and he will perceive that, in
a 3
yj PREFACE.
this, too, I feel a deference for the public °P?mon\^?
a respect for the established course of education,
it is natural to feel and to comply with.
Thus, perhaps, it is less immodest tor an author to
put down what he thinks he may honestly say concern-
ing his own book than to omit those apologies which
custom requires, which give assurance, that he has not
entered upon his task rashly, nor performed it without
some labour and thought, and which are the truest signs
of his respect for the public, and of his care for that
science to which he has devoted his life.
With these intentions and hopes, I offer this book to
the public ; and more particularly to those in whose
education I have a chief concern ; not without a degree
of satisfaction at having accomplished what I think
cannot fail to be useful, and surely not without an ap¬
prehension of not having done (in this wide and difficult
subject) all that may be expected or wished for.
Every book of this kind should form a part of some
greater system of education : it should not only be en¬
tire in its own plan, but should be as a part of some
greater whole ; without which support and connection,
a book of science is insulated and lost. This relation
and subserviency of his own particular task to some
greater whole, is first in an author's mind: he ventures
to look forward to its connection with the general
science, and common course of education ; or he turns it
to a correspondence and harmony with his own notions
of study j and if these notions are to give the com¬
plexion and character to any book, it should be when
it is designed for those entering upon their studies, as
yet uncertain where to begin, or how to proceed.
Hardly any one has been so fortunate as to pursue
the study of his own science under any regular and
perfect plan ; and there are very few with whom a con¬
sciousness 0.1 this does not make a deep and serious im-
ESTfc??,°m?fttuSBi,eriod' accompanied with severe
egiet toi the loss of time never to be retrieved Tn
medicine, perhaps, more than in any other science wp
begin our studies thoughtless and undecided, follow'
whatever is delightful (as much is delightful), Te^cf
PREFACE.
Vll
ing the more severe and useful parts: but as we advance
towards that period in which we are to enter upon a
most difficult profession, and to take our place and sta¬
tion in life, and when we think of the hesitation, anxiety,
and apprehension 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 conscious¬
ness of some idle hours j and (what is more afflicting
still) with an unavailing sense of much ill-directed, un¬
profitable labour : — for there is no study which a young
man enters upon with a more eager curiosity; but, not
instructed in what is really useful, nor seriously im¬
pressed 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 labo¬
rious and useful tasks, and soon falls off' to the vain
pursuit of theories and doctrines.
If I were not persuaded of the important conse¬
quences, of the infinite gain or loss which must follow
the first steps in every profession, I should not feel, but,
above all, I should not venture to show, an anxiety,
which may be thought affected by those who cannot
know how sincere it must be; for, in our profession,
this is the course of things, that a young man, who, by
his limited fortune, or the will of his friends, by absence
from his native country, or by the destination of his fu¬
ture life, is restricted to a few years of irregular, capri¬
cious, ill-directed study, throws himself at once into the
practice of a profession, in which, according to his igno¬
rance 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
completed, 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
A 1 '
viii
PREFACE.
our profession needs to learn, this is, perhaps, the hist,
that he should resist the fascinations of doctrines and
hypotheses, till he have won the privilege of such studies
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 stu¬
dent. 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 acces¬
sible without its help. His desire for real knowledge
revives, only when the opportunity is lost; when he is
to leave the schools of medicine; when he is to give an
account of his studies, with an anxious and oppressed
mind, conscious of his 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 impression, the difficulty and importance of that
art which he is called to practise.
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
succession into neglect and oblivion, never to revive j
fee aspires to the character of a physiologist, to which
want of expedience and a youthful fancy have assigned
a rank and importance which it does not hold in the
estimation ot those who should best know its weak¬
ness or strength. The rawest student, proud of his
physiological knowledge, boasts of a science and a name
PREFACE.
ix
which is modestly disclaimed by the first anatomist, and
the truest physiologist of this or any age. Dr. Hunter
speaks thus of his physiology, and of his anatomical de¬
monstration : — " Physiology, as far as it is known or
has been explained by Haller, and the best of the mo¬
derns, may be easily acquired by a student without a
master, provided the student is acquainted with philo¬
sophy and chymistry, and is an expert and ready ana¬
tomist ; 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 at¬
tend lectures upon physiology as there would be for
gentlemen to attend lectures upon government or upon
the history of England. Lectures upon subjects which
are perfectly intelligible in print cannot be of much
use, except when given by some man of great abilities,
who has laboured the subject, and who has made con¬
siderable improvements either in matter or in arrange¬
ment.
" 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 speculations, will not leave a re¬
putation that will outlive them half a century.
" I always have studied, and shall continue my en¬
deavours, to employ the time that is given up to ana¬
tomical studies as usefully to the students as I can
possibly make it, — and, therefore, shall never aim at
showing what I know, but labour to show and describe,
as clearly as possible, what they ought to know. This
plan rejects all declamation, all parade, all wrangling,
all subtilty : to make a show, and to appear learned and
ingenious in natural knowledge, may flatter vanity; to
know facts, to separate them from suppositions, to range
and connect them, to make them plain to ordinary ca¬
pacities, and above all, to point out the useful applica¬
tions, 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 SIXTH EDITION.
In giving this edition of the Anatomy of the Human
Body to the public, I have recast and arranged the
whole, and have added several subjects to the original
work. I have been careful to revise the descriptions,
and have made some additions to them ; so that I hope
these volumes 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
correct and liberal views of their profession. It will not
soon be surpassed in correctness and minuteness of de¬
scription.
I have not dared to touch the History of the Arteries,
as delivered by my brother : the rapid improvement in
the surgery of the arteries, which followed as a conse¬
quence of the first publication of this part of the Ana-
tomy, has, with me, made it sacred. The nervous sys¬
tem is given here as I have taught it in my lectures of
late years. And the discoveries which I have made
in this department being now acknowledged, I have
thought myself at liberty to incorporate the new views
of the nervous system with this edition of the System of
xii
PREFACE.
Anatomy of the Human Body. I have also introduced,
in their proper places, the substance of such essays or
observations as I have published from time to time,
when they have seemed to deserve this by the interest
they have excited.
CHARLES BELL.
Soho-Square, London,
Oct. 1826.
CONTENTS
of
THE FIRST VOLUME.
ANATOMY
of the
BONES, MUSCLES, AND JOINTS.
Page
Introductory View of the Animal Economy, - 1
Of the Skeleton, ------ 9
Of the Trunk, - - - - - - - 19
the bones of the spine, pelvis, and thorax.
Of the Spine — Uses of the Spine — its Motions —
and the Division of the Vertebrae, - ib.
General Description of a Vertebra.
1. Body of the Vertebra, - - 21
2. Articulating, or Oblique Processes, - 22
3. Spinous Processes, - - ib.
4. Transverse Processes, - 23
Vertebrae of the Loins, - - ib.
Vertebrae of the Back, - - 24
Vertebrae of the Neck, - - 26
Atlas, - - - - 27
Dentata, - - - - 30
Of the Spine generally, - - 31
Medullary Tube and the Passage of the Nerves, ib.
Intervertebral Substance, - - - 32
Motions of the Vertebrae, - - - 33
xiv
contents.
Page
Ribs and Sternum.
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, - 34
The Parts of the Rib, as the Head, Neck—Sur¬
face for articulating with the Transverse Pro¬
cess — Angle of the Rib, - -35
Size and Length of the Ribs — the Cartilages
of the Ribs, - - - -37
Motion of the Ribs, - - - 39
ii. Of the Sternum, and its Parts, - - 39
Ensiform Cartilage - - -41
Of the Pelvis, - - - 42
i. Os Sacrum, - - - - ib.
ii. Os Coccygis, - - 45
iii. Ossa Innominata, - 46
i. Os Ilium, or Haunch-Bone — 1. Ala
— Spine—Spinous Processes, Posterior
and Anterior — 2. Dorsum — 3. Costa
—4. Linea Innominata, - - 47
ii. Os Ischium, or Hip-Bone — 1. Body
— 2. Tuber — 3. Ramus, - - 49
iii. Os Pubis, or Share-Bone — Body —
Crest — Ramus, - - 50
Recapitulation of the chief Points of the Ana¬
tomy of the Pelvis, - - 51
Size of the Pelvis in Man and Woman, - 52
Remarks on the Separation of the Bones of the
Pubes during Labour, - - 53
Femur, - - - - - 58
BONES OF THE THIGH, LEG, AND FOOT.
1. Body, - - ib.
2. Head, - - - - - 59
3. Neck, - - - ib.
4. Trochanter major, - - - 60
5. Trochanter minor, - - - ib.
6. Linea aspera, - - - 61
7. Condyles, - » - - ib.
Tibia, ... - - - 63
1. Upper head, - - - - ib
2. Body, - - - 64
3. Lower Head —- Inner Ankle, - - ib:
contents.
xv
Page
1" IBULA, - - - - - - 66
1. Upper Head, - - - ib.
2. Lower Head — Outer Ankle, 67
Rotula, or Patella, or Knee-pan, - - 68
Tarsus, or Instep, - - - 69
1. Astragalus, - -70
2. Os Calcis, - - - 71
3. Os Naviculare, - - 72
4. Os Cuboides, - - -73
5-
6. > Cuneiform Bones, - - ib.
7. J
Metatarsus and its five Bones, - - - ib.
Toes, - - - - 75
Sesamoid Bones, - - - - ib.
BONES OF THE SHOULDER, ARM, AND HAND.
Shoulder.
i. Scapula, or Shoulder-Blade, - - 76
1. The flat Side of the Scapula, - 77
2. The upper flat Surface, - - ib.
3. The Triangular Form of the Scapula
-—Costa — Basis, - - 78
4. The Glenoid, or Articulating Cavity, 79
5. The Neck, - ib.
6. The Spine, - - - ib.
7. The Acromion Process, - - 80
8. The Coracoid Process, - - ib.
ii. Clavicle, or Collar-Bone, - - 81
1. The Thoracic End and Joint, - 82
2. The Outer End, and its union with the
Scapula, - ib.
Arm.
Os Humeri, - - - - 83
1. Head, - - ib.
2. Neck, - ib.
3. Tuberosities, - - - 84
4. Groove for the Tendon of the Biceps
Muscle, - - ib.
5. Ridges leading to the Condyles, - ib.
6. Condyles, - - 85
7. Articulating Surface for the Elbow-
ioint, and general Explanation of the
Joint, - - - 86
8. Hollows for the Olecranon and Coro-
noid Processes of the Ulna, - ib.
xv i
contents.
Page
Ulna and Radius.
1. Greater Sigmoid Cavity, formed by
1. Olecranon, -
2. Coronoid Process, - ~ 1"*
2. Lesser Sigmoid Cavity for receiving
the Head of the Radius, - 88
3. Ridges, - ib.
4. Lower Head of the Ulna, - - ib.
5. Styloid Process of the Ulna, - ib.
Radius.
1. Body, - - 89
2. Upper Head, - - ib.
3. Neck, - - - ib.
4. Point for the Implantation of the Biceps
Flexor Cubiti, - - 90
5. Lower Head, - - ib.
6. Styloid Process of the Radius, - ib.
7. Ridge and Grooves, - -91
Hand and Fingers.
General Explanation of the Hand and Wrist,
Carpus, Metacarpus, and Fingers.
Carpus, or Wrist, - - 91
1. Row forming the Wrist, - - 92
1. Os Scaphoides, - - ib.
2. Os Lunare, - - ib.
3. Os Cuneiforme, - - 94
4. Os Pisiforme, - - ib.
2. Row supporting the Metacarpal Bones, ib.
1. Trapezium, - - ib.
2. Trapezoides, - 95
3. Os Magnum, - _ jb.
4. Os Unciforme, - - ib
Metacarpus, - '
Fingers,
98
OF THE SKULL IN GENERAL.
Importance of the Anatomy of the Skull, - - 99
The Tables and Diploe of the Bones of the Skull, - ioo
Classification of the Bones of the Head, - - 102
Enumeration and short Description of the Bones of the
Cranium, - - - - 103
The Sutures, - - - - 104
Remarks on the Formation, Nature, and Use of Sutures, 106
contents.
xvii
Page
DESCRIPTION OF THE INDIVIDUAL BONES OF THE SKULL.
Os Frontis, - - _ 113
1. Orbitary Plates, - - ib.
2. Fissura .ZEthmoidea, - - - ib.
3. Superciliary Ridge, - ib.
4. Pores and minute Foramina, - - ib.
5. Superciliary Hole, - - -114
6. Foramen Orbitale, - - ib.
7. Angular Processes, - ib.
8. Nasal Process, - - - ib.
9. Temporal Ridge, - - - 115
10. Frontal Sinuses, - - ib.
11. Partitions of the Sinuses, - - ib.
12. Frontal Ridge, or Spine, - - 117
13. Groove, - - ib.
14. Foramen Caecum, - - ib.
15. Pit of the Trochlea, - - ib.
16. Pit for the Lachrymal Gland, - - 118
Os Parietale, - - - ib.
1. The Four Angles, - - ib.
2. Groove for the Sinus, - - - 119
3. Groove for the Meningeal Artery, - ib.
Os Occipitis, - - 120
i. External Surface, - - 121
1. Transverse Spines, - - ib.
2. Crucial Spine, - - ib.
3. Posterior Tuberosity, - - ib.
ii. Internal Surface, - - - ib.
1. Great Internal Ridge and Tentorium
Cerebello Super-extensum, - ib.
2. Hollows of the Occipital Bone, - 122
iii. Processes of the Occipital Bone, - - ib.
1. Cuneiforme, - ib.
2. Condyles, - - - ib.
iv. Holes, - - 123
1. Foramen Magnum, - - ib.
2. Hole for the Ninth Pair of Nerves, - ib.
3. Hole for the Cervical Vein of the Neck, ib.
4. Common Hole, - - 124
Os Temporis, - - jj5-
Squamous part, - - - ib.
Petrous part, - ~ - ib.
Processes, - ~ - 125
1. Zygomatic, - ~ - ib.
2. Styloid, - - - ib.
VOL. I. a
xviii
contents.
Page
3. Vaginal, - "
4. Mastoid or Mamillary, - " jj3,
5. Auditory, - - - id.
Holes, - - 1 ^
For the Ear, - - - lb.
1. Meatus Auditorius Externus, - jb.
2. Internus, - ib.
3. Small Hole receiving a Branch from
the fifth Pair of Nerves, - 128
4. Stylo-Mastoid Hole, - - ib.
5. Hole for the Eustachian Tube, - ib.
For Blood-vessels, - - 129
1. For the Carotid Artery, - - ib.
2. For the Great Lateral Sinus, called
the Common Hole, as formed partly
by the Temporal, partly by the Oc¬
cipital Bone, - - ib.
3. Small Hole on the Outside of the
Temporal Bone, - - 130
Os ^Ethmoides, - - - 131
1. Cribriform Plate, - - 132
2. Crista Galli, - ib.
3. Nasal Plate, or Azygous Process, 133
4. The Labyrinth, - ib.
5. Spongy Bones, - - ib.
6. Orbitary Plate, or Os Planum, - 184
7. Os Unguis, - - - ib.
S. Cellsj - - ib.
Os Sphenoides, - - - -135
Processes, - - - ib.
1. Alae, - - 136
2. Orbitary Process, - - ib.
3. Spinous Process, - - - ib.
4. Styloid Process, - _ ib.
5. Pterygoid Processes, - - 137
External.
Internal.
6. Azygous Process, - - - ib.
7. Clynoid Processes, - - 138
Anterior.
Posterior.
Sella Turcica, and its Cells, - _ ib.
Holes, - - - j gg
1. Foramen Opticum, - - - ib
2. Lacerum, -
3. Rotundum, _ 140'
CONTENTS.
xix
Page
4. Foramen Ovale, - -141
5. Spinale, - - ib.
6. Pterygoid, or Vidian Hole, - ib.
Common Holes, - - - ib.
Os Unguis, or Lacrymale, - - - 143
BONES OF THE FACE AND JAWS.
Ossa Nasi, ... . . 143
Ossa Maxillaria Superiora, - . 144
Processes, - « - 145
1. Nasal, - ib.
2. Orbitary, - - - ib.
3. Malar, - - - ib.
4. Alveolar, - - - ib.
5. Palatine Process, - 146
Antrum Maxillare, or Highmorianum, - 147
Holes, - - 148
1. Infra Orbitary, - ib.
2. Foramen Incisivum, or Anterior Pala¬
tine Hole, - - 149
3. Posterior Palatine Hole, - - ib.
4. Lachrymal Groove, - ib.
5. Lateral Orbitary Fissure, - ib.
6. Alveolar Foramina, - 150
Ossa Palati, - - ib.
Processes, - - ib.
1. Palatine Plate or Process, - - ib.
Middle Palatine Suture, - 151
Transverse Palatine Suture, - ib.
2. Pterygoid Process, - - ib.
3. Nasal Plate or Process, - - ib.
Ridge, - - - ib.
Groove, - - ib.
4. Orbitary Process, - - 152
Palatine Cells, - ib.
Ossa Spongiosa, or Turbinata Inferiora, - - ib.
Vomer, - - - - 153
Os Mal^e, - - - - 154
Processes, - - - ib.
1. Upper Orbitary, - - ib.
2. Inferior Orbitary, - - ib.
3. Maxillary, - - - ib.
4. Zygomatic, ~ - - 155
5. Internal Orbitary, - - ib.
6. Foramen, - - ib.
a CZ
xx
contents.
Os Maxillae Inferioris,
Processes,
1. Coronoid,
2. Condyloid,
3. Cervix,
4. Semilunar Notch,
5. Alveolar,
6. Spina Interna,
Holes,
1. Large Hole in the inner Side for the
Entry of the Lower Maxillary Nerve
and Artery, ... - ib.
2. Mental Hole, - ib.
Review of the Skeleton, - - - 159
Review of the Bones of the Head, - - 176
Craniology, - - - 187
Varieties in the Forms of the Head, indicative of na¬
tional Peculiarities, - - 193
Of the Formation and Growth of Bones, - 197
History of the Doctrines of Ossification, - 198
Phenomena of Ossification, - - 202
Blood Vessels and Absorbents of Bones, and Proofs of the
Deposition and Re-absorption of the Bony Matter, - 207
Nerves of Bones, and Proofs of the Sensibility of Bones, 212
The Process of Ossification described, - - 214?
1. The various Forms, and numerous Points of Ossi¬
fication, - - - - 215
2. The Heads and Processes of long Bones, - 216
3. The Cavity of long Bones, - _ ib.
4. The Cancelli, - - - - 217
5. The Marrow, - - - ib.
6'. The Lamellae, or Bony Plates, - - 218
7. The Holes of Bones, - - 219
8. The Vessels, - - - ib.
9. The Periosteum, - - 220
10. The Cartilages, - - - 221
The Callus and Regeneration of broken Bones, - 222
Of the Teeth, by Mr. Charles Bell, _ _ 225
Description of the Human Adult Teeth, _ 226
1. The Incisores, - -
2. The Cuspidati, or Canine Teeth, _ _ 227
3. The Bicuspides, - - ib.
4. The Molares, or Grinding Teeth, _ 228
Of the first Set of the Teeth, the Milk or Deciduous
Teeth, ~ - 229
Page
- 155
- ib.
- ib.
- 156
ib.
- 157
- ib.
- ib.
- 158
CONTENTS.
Page
Of the Structure of the Teeth, - - -231
Of the Enamel, - - 232
Of the central bony Part of the Teeth, - - 234
Of the Vascularity and Constitution of the bony Part
of the Tooth, - 235
Of the Gums, - - 239
Of the Formation and Growth of the Teeth, - 24-1
Of the Growth of the second Set of Teeth, and the
shedding of the first, - - 246
OF THE MUSCLES.
Their Texture, and the Varieties in the Arrange¬
ment of their Fibres, - - 250
Mechanical Power sacrificed to Velocity, - 254
Tendons, Fasciae, and Aponeurosis, - - 261
MUSCLES OF THE FACE, EYE, AND EAR.
Muscles of the Face.
1. Occipito Frontalis, - - 262
2. Corrugator Supercilii, - - 264
3. Orbicularis Oculi, or Palpebrarum, - ib.
4. Levator Palpebrae Superioris, - - 265
Muscles of the Nose and Mouth.
5. Levator Labii Superioris, et Alae Nasi, - ib.
6. proprius, - - 266
7. Levator Anguli Oris, or Levator Communis La-
biorum, - - ib.
8. Zygomaticus Major, - - ib.
9. Minor, - - 267
10. Buccinator, - - - ib.
11. Depressor Anguli Oris, - - 268
12. Depressor Labii Inferior is, or Quadratus Genae, ib.
13. Orbicularis Oris, - - 269
14. Depressor Labii Superioris, et Alae Nasi, - 270
15. Constrictor Nasi, - - 271
16. Levator Menti, - - - ib.
Muscles of the External Ear, - 271
17. Superior Auris, - - 272
18. Anterior Auris, - - - ib.
19. Posterior Auris, - ib.
20. Helicis Major, - - - ib.
21. Minor, - 273
a 3
xxii
contents.
22. Tragicus,
23. Antitragicus,
24. Transversus Auris,
Muscles of the Eye-Ball.
General Explanation of these Muscles,
25. Rectus Superior,
26. Interior,
27. — Internus,
28. Extern us,
29. Obliquus Superior,
30. Inferior,
MUSCLES OF THE LOWER JAW, THROAT, AND TONGUE.
Muscles of the lower Jaw.
31. Temporalis, - - 277
32. Masseter, - - 278
33. Pterygoideus Internus, or Major, - ib.
34. ■ Externus, or Minor, - - 279
Muscles lying on the fore Part of the Neck, and
moving the Head.
35. Platysma Myoitles, - - ib.
36. Sterno-cleido-Mastoideus, - - 280
Muscles of the Throat and Tongue.
Explanation of certain Bones and Cartilages forming the
Basis of the Throat and Tongue, and the Centre of
their Motions, - - - - 281
1. Os Hyoides. — Its Cornua. — Its Appendices, or
perpendicular Processes, - - - ib.
2. Larynx, Trachea, or Windpipe - _ 282
1. Thyroid, or Scutiform Cartilage, - _ ib.
2. Cricoid Cartilage, - - - ib.
3. Arytenoid Cartilages, and RimaGlottidis formed
by them, - - - ib.
4. Epiglottis, - - - - 284
Recapitulation and View of the Constitution of the
Larynx, -
]. Muscles of the Throat.
i. Muscles which pull the Throat down,
37. Sterno-hyoideus,
38. Sterno-thyroideus,
39. Omo-hyoideus,
Action of these Muscles,
ii. Muscles which move the Throat upwards,
40. Mylo-hyoideus,
41. Genio-hyoideus,
Page
- 273
- ib.
- ib.
- ib.
- 275
- ib.
- ib.
- ib.
- ib.
- 276
- ib.
- ib.
- 285
- 286
- ib.
- ib.
- ib
- 287
contents.
Page
42. Stylo-hyoideus, - - 287
43. Digastricus, or Biventer Maxillae Inferioris, - 288
iii. Muscles moving the Parts and Cartilages of the
Larynx upon each other, - - ib.
44. Hyo-thyroideus, - - 289
45. Crico-thyroideus, - - ib.
46. Musculus Arytenoideus Transversus, - ib.
47. Obliquus, - - 290
48. Crico-Arytenoideus Posticus, - - ib.
49. Lateralis, - - ib.
50. Thyro-Arytenoideus, - ib.
iv. Muscles of the Palate and Pharynx, - 291
51. Azygos Uvulae, - - ib.
52. Levator Palati Mollis, - 292
53. Circumflexus Palati, or Tensor Palati Mollis, - ib.
54. Constrictor Isthmi Faucium, - - 293
55. Palato-Pharyngeus, - ib.
Pharynx explained, - ib.
56. Stylo-Pharyngeus, - - 294
57. Constrictor Superior, - - 295
58. Medius, - - ib.
59. Inferior, - - ib.
(Esophagus, - ib.
60. Vaginalis Gulae, - 296
2. Muscles or the Tongue.
61. Hyo-glossus, - ib.
62. Genio-hyo-glossus, - ib.
63. Lingualis, - - - ib.
64. Stylo-Glossus, - - 297
Motions of the Tongue performed by these
Muscles, - - ib.
OF THE MUSCLES OF THE ARM, INCLUDING THE MUSCLES
OF THE SCAPULA, ARM, FORE-ARM, AND HAND.
Muscles oe the Scapula, - - 297
i. Muscles moving the Scapula upwards and back¬
wards, - - - 298
65. Trapezius, - - - ib.
66. Levator Scapulae, or Levator Proprius Angu-
laris, - - ^99
67. and 68. Rhomboideus, - - 300
1. Minor, - - jb.
2. Major, - - - ib.
a 4
xxiv
contents.
Page
ii. Muscles which move the Scapula downwards and
forwards, - -
69. Serratus Major Anticus, - -
70. Pectoralis Minor, - - 301
71. Subclavius, - - 302
Motions of the Scapula, - - it).
Muscles moving the Os Humeri, or Arm-Bone.
72. Pectoralis Major, - - ib.
73. Latissimus Dorsi, - - 303
74. Deltoides, - - - 305
75. Coraco-brachialis, - 306
76. Supra Spinatus, - - - - ib.
77. Infra Spinatus, - - 307
78. Teres Minor, - - 308
79. Major, - ib.
80. Subscapularis, - - 309
Motions of the Humerus, and Use and Effect of each
of these Muscles in forming and strengthening the
Joint, - - ib.
Muscles moving the Fore-Arm, - - Sll
i. Muscles bending the Fore-Arm, - •• ib.
81. Biceps Flexor Brachii, - - ib.
82. Brachialis Internus, - - - 312
ii. Muscles extending the Fore-Arm, - - ib.
83. Triceps Extensor, - - - 313
84. Anconaeus, - - ib.
Muscles situated on the Fore-Arm moving the
Radius, Carpus, and Fingers.
Fascia of the Arm, - - - 314
Arrangement of these Muscles, the Points of Ori¬
gin and Insertion, and the Motions of Pronation
and Supination, Flexion and Extension, ex¬
plained, - - - - 315
i. Flexors, arising from the Inner Condyle, - ib,
85. Supinator Radii Longus, - - 318
86. Brevis, - - 319
87. Pronator Radii Teres, - - - ib.
88. Quadratus, - _ 320
89. Palmaris Longus, - - - ib.
90. Brevis, or Cutaneus, - _ 322
91. Flexor Carpi Radialis, - _
92. Ulnaris, - _ 323
93. Flexor Digitorum Sublimis, - _
94. Profundus, vel Perforans, 325
95. Lumbricales, - - 326
96. Flexor Longus Pollicis, - _ 327
contents.
xxv
ii. Extensors, arising from the Outer Condyle.
97. Extensor Carpi Radialis Longior, - 328
98. Brevior, - - 329
99. Ulnaris, - - 330
100. Digitorum Communis, - - ib.
101. Minimi Digiti, or Auricularis, - 331
102. Primus Pollicis, "1 - 333
103. Secundus Pollicis, > - ib.
104. Tertius Pollicis, j - 334
105. Indicator, - ib.
Muscles seated on the hand.
General description of these Muscles, - - 335
106. Abductor Pollicis, n - 336
107. Opponens Pollicis, f - ib.
108. Flexor Brevis Pollicis, ? - 337
109. Adductor Pollicis, J - 338
110. — Minimi Digiti, ib.
111. Flexor Parvus Minimi Digiti, I - 339
112. Abductor Minimi Digiti. J
113. Indicis, - - ib.
114. Interossei Interni, - 340
115. Externi, - ib.
MUSCLES OF RESPIRATION, OR OF THE RIBS.
General Explanation and Table of these Muscles, - 341
116. Serratus Superior Posticus, » - 342
117. Inferior Posticus, - ib.
118. Levatores Costarum, - - 343
119. and 120. Intercostales, - - - ib.
121. Triangularis Sterni, or Sterno-costalis, - 344
MUSCLES OF THE HEAD, NECK, AND TRUNK.
Muscles of the Head and Neck.
122. Splenius,
123. Complexus,
124. Traclielo-mastoideus,
125. Rectus Minor,
126. Major,
127. Obliquus Superior,
128. 'Inferior,
Muscles of the tiiunk.
129. Quadratus Lumborum,
130. Longissimus Dorsi,
131. Sacro-Lumbalis,
- 346
- 347
- 348
- 349
ib.
350
- 350
- 351
- 352
- ib.
xxvi
contents.
Page
132. Cervicalis Descendens, - 353
133. Transversalis Colli, - - 354
Arrangement of the intricate Set of Mus¬
cles filling up the Hollows and Inter¬
stices among the Spines and Processes
of the Vertebrae, - - -355
134. Spinalis Cervicis, - 356
135. Dorsi, - - ib.
136. Semi-spinalis Dorsi, - - ib.
137. Multifidus Spinse, - - ib.
138. Inter-spinalis Colli, Dorsi, et Lumborum, - 358
139. Inter-transversales, - - - ib.
Muscles on the fore part of the Head and Neck,
completing the Catalogue of those belonging to the Spine.
140. Rectus Internus Capitis Major, - - 358
141. Minor, - - 359
142. Capitis Lateralis, - - ib.
143. Longus Colli, - - - ib.
144. Scalenus, - - - ib.
OF THE MUSCLES OF THE ABDOMEN", AND OF THE
DIAPHRAGM.
Muscles of the Abdomen, - 347
Importance of the Anatomy of the Abdominal
Muscles —General Explanation of these Mus¬
cles— their Uses — Arrangement, - - 361
145. Obliquus Externus, - - 362
146. Internus, - 363
147. Transversalis Abdominis, - - 364
148. Recti, - - ib.
149. Pyramidalis, - - - 365
Explanation of the Lines, Rings, &c. of the
Abdominal Muscles.
1. Linea Alba, - 366
2. Semilunaris, - _ ib.
3. Sheath for the Rectus, - _ ib.
4. Umbilicus, - _ 357
5. Ring of the Abdominal Muscles, - ib.
Crescent.
150. Cremaster Muscle of the Testicle, - 369
6. Ligament of the Thigh, - _ ib.
Explanation of the different Kinds of Hernia
and the Points at which the Bowels are pro¬
truded.
contents.
xxvii
Page
Diaphragm.
151. The Diaphragm, - - 371
1. The Greater, or Upper Muscle of the
Diaphragm, - - 372
2. The L esser Muscle of the Diaphragm, - ib.
3. The Tendon in the Centre of the
Diaphragm, - - - 373
Vessels perforating the Diaphragm, - 374
1. Aorta. - - ib.
2. (Esophagus, - - ib.
3. The great Vena Cava, - - ib.
The Tendon of the Diaphragm, - ib.
Uses of the Diaphragm, - - 375
THE MUSCLES OF THE PARTS OF GENERATION, AND
OF THE ANUS, AND PERINiEUM,
General Idea of these Muscles, - - - 376
Fascia, or Aponeurosis, - - ib.
152. Erector Penis, - - ib.
153. Transversalis Perinaei, - - 377
154. Ejaculator, - - - ib.
155. Sphincter Ani, - - 378
156. Levator Ani, - - ib.
157. Musculus Coccygeus, - - 380
Perinaeum,—the Point where all these Muscles are united, ib.
Course of the Incision in Lithotomy, - - ib.
Muscles of the Female Perinaeum, - - 381
MUSCLES OF THE THIGH, LEG, AND FOOT.
Muscles moving the Thigh-bone, - - 371
General Description of these Muscles — Classi¬
fication and Arrangement of them — and Table
of their Implantations, and of the Motions
which they perform, - - 382
Fascia of the Thigh, - - - 384
158. Musculus Fascialis, or Tensor Vaginae Fe-
moris, - - 386
159. Psoas Magnus, - 387
160. Parvus, - - - ib.
161. Iliacus Internus, - - 388
162. Pectineus, or Pectinalis, - - 389
163. Triceps Femoris, - - ib.
1. Adductor Longus, - - 390
2. B re vi s, - - ib.
3. - Magnus, - - 391
xxviii
contents.
164. Obturator Externus,
165. Glutaeus Maximus,
156. Medius, or Minor,
167. Minimus,
J®®; } Gemini,
170. Pyriformis,
171. Obturator Internus,
172. Quadratus Femoris,
Motions of the Thigh, and Action of these Muscles, ib.
Muscles of the Leg, - - - ib.
Arrangement of these Muscles, - - 398
i. Extensors of the Leg, - - ib.
173. Rectus Femoris, or Rectus Cruris, - ib.
174. Cruraeus, - - 399
Sub-crursei, being Slips only of the Cruraeus, ib.
175. Vastus Externus, - - 400
176. Internus, - - ib.
Uses of these Muscles, - - - 401
ii. Flexors of the Leg, - - 402
177. Sartorius, - - - ib.
178. Gracilis, or Rectus Internus Femoris, - 403
179. Semitendinosus, - 404
180. Semimembranosus, - - ib.
181. Poplitaeus, - - 405
182. Biceps Cruris, - - ib.
Fascia, - - 406
Muscles of the Foot, - - 407
Arrangement, - - ib.
i. Extensors.
183. Gastrocnemius, - - ib.
184. Soleus, - - 408
185. Plantaris, - - - ib.
186. Peronaeus Longus, - - 4-09
187. Brevis, - - 410
188. Tertius, - - 411
ii. Flexors.
189. Tibialis Posticus, - - - 412
190. — Anticus, - - - ib.
Muscles of the Toes, - 413
191. Flexor Longus Pollicis, - _ - 414
192. Digitorum Pedis, Perforans, - ib.
193. Massa Carnea J. Sylvii, or Plantae Pedis, - 415
194. Flexor Brevis Digitorum, - - 416
195. Lumbricales, - - - 417
Page
392
- 393
- ib.
- 394
- ib.
- ib.
- 395
- 396
CONTENTS. xxix
Page
Extensors of the Toes, - - - 418
196. Extensor Longus Digitorum Pedis, - ib.
197. Digitorum Brevis, - - ib.
198. Pollicis Proprius - 419
Crucial Ligament.
199. Abductor Pollicis, - 420
200. Flexor Brevis Pollicis, > - - - 421
201. Adductor Pollicis, J - ib.
202. Transversalis Pedis, » - ib.
203. Abductor Minimi Digiti, - - 422
204. Flexor Brevis Minimi Digiti, - - ib.
205. Interossei Interni, - - - ib.
206. Externi, - - 423
Fascia of the Leg, - - ib.
Plantar Aponeurosis, - - 424
OF THE MUSCULAR POWER.
OF THE CELLULAR SUBSTANCE, AND OF THE TENDONS,
LIGAMENTS, BURSiE, AND FASCI2E, AND ALL THE PARTS
WHICH BELONG TO THE BONES OR MUSCLES, OR WHICH
ENTER INTO THE CONSTITUTION OF A JOINT.
Of the Nature of the Cellular Substance,
General Explanation of the Tendons, Ligaments, &c.
Of the Forms of the Cellular Substance,
1. Its Cells, and their Use, -
2. Bursa Mucosa, - -
3. Vagina, or Fascia, - -
4. Tendons, - -
5. Periosteum, -
6. Vagina, or Sheaths of Tendons,
7. Capsules of the Joints, -
8. Ligaments of Joints, -
Recapitulation and Review of the Connections of these
Parts, -
Constitution and Nature of those less sensible Parts,
OF THE JOINTS.
Joints of the Head and Spine, - - 451
Different Kinds of Joints and Ligaments, and their
Names, - ~ ~ - ib.
The Motions of the Head and Spine, - - ib.
436
440
441
ib.
442
ib.
443
444
ib.
445
ib.
446
447
XXX
CONTENTS.
Page
The Provisions for these Motions, - - 452
i. Joint of the Head with the Neck, - - ib.
1. Articulation of the Occiput and Atlas, - ib.
Form of the Joint and Capsules for the
Condyles, - - 453
2. Flat Membranous Ligament from the Ring
of the Atlas to the Ring of the Occipital
Hole, - - ib.
3. Articulation of the Atlas with the Dentata, ib.
Capsules betwixt the Condyles of the Ver¬
tebrae, - - - ib.
Transverse Ligament embracing the Neck of
the Tooth-like Process — Capsular Liga¬
ment, - - - ib.
Ligament betwixt the Tooth-like Process and
Occipital Hole, - - - ib.
ii. Joints of the Common Vertebrae with each other.
. Intervertebral Substance, and Intervertebral
Ligaments, - - - ib.
External or Anterior Vagina, or Ligament of
the Spine, - - - 454«
Internal Ligaments, - - ib.
Ligamenta Subflava Crurum Processuum
Spinosorum — Membranae Interspinals
—Ligamenta ProcessuumTransversorum.
Posterior or Internal Ligament of the Spine, 455
Apparatus Ligamentosus Colli, - 456
Joint of the Lower Jaw, - - 457
Ligaments of the Jaw, - 458
— Vertebral Column, - - ib.
seen on making the Section of the Spine, ib.
betwixt the Head and Upper Vertebra, ib.
Joints of the Ribs, - 459
Ligamenta Capitelli Costarum, - - 460
Ligamentum Transversarium Externum, - ib.
■ Internum, - ib.
Capsule and Ligaments belonging to the Car¬
tilages, - - - ib.
Ligaments betwixt the Rib and the Spine, - 461
Anterior Extremity of the Ribs and Sternum, ib.
JOINTS OF THE SHOULDER, ARM, AND HAND.
Joints of the Clavicle, - - - 461
With the Sternum, - - - ib.
Scapula, - - 462
contents. xxxi
Page
Joint of the Shoulder, - 463
Ligaments about the Shoulder, - - 465
Joint of the Elbow, - - - ib.
Interosseous Ligament, - - 465
Chorda Transversalis Cubiti, - - ib.
Ligaments of the Elbow-Joint, - - ib.
The General Capsule of the whole Joint, - 466
The Lateral Ligaments, External and Internal, 467
The Coronary Ligament of the Ulna, - ib.
Accessory Ligaments, - - 468
Wrist, - - - - ib.
Articulation of the Scaphoid and Lunated Bones
with the Scaphoid Cavity of the Radius, - 469
Articulation of the Radius wiih the Ulna for the
turning Motions of the Hand, - - ib.
Articulation of the Bones of the Carpus with each
other, - - - - 470
Articulations of the Metacarpus, - - 471
Recapitulation of Ligaments, - - ib.
Joints of the Fingers, - - ib.
Ligaments of the Pelvis, - 473
Ligamentum Anticum Superius and Inferius, - ib.
Sacro Iliac Ligament and Ligamenta Dorsalia
Vaga, - - - 474
Ligamentum Sacro Ischiaticum, Majus and
Minus, - - ib.
Ligamenta Longitudinalia, - - ib.
Annulus Ligamentosus and Triangular Ligament, ib.
Membrana Obturans, - - - 475
JOINTS OF THE THIGH, LEG, AND ANKLE.
The Hip-Joint, - - - - 475
The Ligamentum Labri Cartilaginei Transver-
sale, - - ib.
The Capsule of the Joint, - - ib.
The Internal Ligaments, - - --476
Recapitulation of Ligaments, - - 478
Knee-Joint, - - - - ib.
1. The External Ligaments, - - ib.
Capsule — and Ligamentum Posticum Win-
slowii, - - - 479
Lateral Ligaments, - - 480
Ligamentum Laterale Internum, - ib.
_ Externum Longius, - ib.
— Brevius, - ib.
xxxii
contents.
Page
2. The Internal or Crucial Ligaments of the Knee, 480
Posterior Crucial Ligament, - - ib.
Anterior , ~ - 481
Semilunar, or movable Cartilages, - - ib.
Ligamentum Mucosum—and Ligamentum Alare
Majus et Minus - - 482
Ligamenta Cartilaginum Lunatarum, - ib.
Ligamentum Transversale Commune, - ib.
Bursas Mucosae of the Knee-Joint, - - 483
Recapitulation, explaining the Constitution of this
Joint, and Uses of its several Parts, - - 484
List of the Ligaments of the Knee-Joint, - - 486
Articulation of the Fibula with the Tibia, - ib.
Ankle-Joint.
Ligamentum Superius Anticum, - - 487
Posticum, - ib.
• Inferius Posticum, - - ib.
Capsule, - - ib.
Ligamentum Deltoides, - - ib.
Fibulae Anterius, - - 488
Perpendiculare, - ib.
Inter Fibulam et Astragalum
Posterius, - ib.
Recapitulation of Ligaments, - - ib.
Union betwixt the Bones of the Tarsus, - - 489
Joints of the Metatarsus and Toes, - ib.
Aponeurosis Plantaris Pedis, - - 490
Bursae Mucosae of the Ankle and Foot, - 491
Conclusion and Enumeration of the Joints, - 492
Enumeration of the Bursae Mucosae, - 493
OF THE CIRCULATING SYSTEM.
Qualities of the Blood, - - 4,95
Of the Red Globules, - - - ib.
Coagulable Lymph, - _ 4,99
Serum, - - - - 501
Life of the Blood, - ^Q2
Chemistry of the Blood, - - 503
Influence of Air upon the Blood, - 509
1. In reddening the Blood, - _
2. In communicating its stimulant Powers, - 511
contents.
xxxiii
of the
HEART, ARTERIES, AND VEINS.
OF THE HEART.
OF THE MECHANISM OF THE HEART.
Page
General View of the Circulating System, - -512
Of the Parts of the Heart, - - -521
Venae Cavae, - - ib.
Right Sinus of the Heart, - - 522
Tuberculum Loweri, - - 523
Auricle, - - - ib.
Auricular Valves, - 524
Right Ventricle, - 525
Pulmonic Artery, - - 526
Sigmoid Valves, - - - 527
Left Auricle, - 528
Mitral Valve, - - 530
Semilunar Valves of the Aorta, - - ib.
Aorta, - - - - 531
Of the Coronary Vessels, - - ib.
Eustachian Valve, - 536
Irritability and Action of the Heart, - - 543
Posture of the Heart, - 550
Pericardium, - 553
Conclusion, - 559
Of the Respiration of Animals, - 566
Its Effects upon the Blood," - ib.
Of Animal Heat and the Heat of the Blood, - - 570
Of the Membranes of Cavities, and particularly of the
Membranes of the Thorax, - - - 574
Of the Pleura, - - - - 577
Mediastinum, - - - 581
■ Pericardium, - " 584
Thymus Gland, - ~ - 585
Of the Lungs, - - " 586
Of the Trachea, or Aspera Arteria, - - 587
■ Thyroid Gland, - " 589
Bronchiae, - ~ ~ 590
VOJ.. I. b
xxxiv
CONTENTS.
Page
Bronchial Cells, - 590
Other Tubes or Vessels which enter into the texture of
the Lungs, - 596
Course of the Blood in the Lungs, - - 597
Of the Motions of the Thorax, and of Respiration in
Man, - - 598
INTRODUCTION.
Human anatomy is a part only of a more general
science, which embraces the knowledge of the struc¬
ture of all classes of animals, from the most simple
to the highest; but it is by far the most important
part. It should be kept before the anatomist and
naturalist, as a subject of suitable dignity and use¬
fulness, not only to animate their endeavours, but
to give them a direction, and to prove a cri¬
terion of their success in the pursuit of useful
knowledge. On the other hand, human anatomy
cannot be highly cultivated without the assistance of
what is called comparative anatomy. It cannot be
considered a liberal study, nor properly preserved in
relation to general science, without a continual re¬
ference to natural history, and the chain of animal
existence.
Whether there be a perfect chain and gradation of
existence, some will doubt; that is to say, when the
naturalist has arranged animals according to their
exterior appearance, the anatomist deranges his ideas,
by exhibiting, in the internal structure, transitions
and gradations which he did not contemplate, and
principles of arrangement which he had not foreseen.
But this does not controvert the general principle,
that there is a chain of existence through the whole
of nature. It only throws us back, mortified that we
vol. t. b
INTRODUCTION.
do not perfectly comprehend the whole system ; a
conclusion which, however humbling, is exactly what
man experiences in the pursuit of every other
department of knowledge, whether the subject of his
contemplation be the earth he inhabits, the creatures
which partake it with him, or his own faculties and
nature, and his condition in creation. And let us
make the best of this truth; let us view it as promising
to us an inexhaustible field for enquiry, and an ever
new hope of discovery.
In respect to animals, there are principles in
operation, and a structure or organization, which
extend, with a certain resemblance, through the
whole. There is a system of parts to give form;
there is a substance the seat of irritability; there are
parts the seat of sensibility and enjoyment; and the
powers or endowments of those parts, however dif¬
ferent, are supplied through the same means. They
have a circulation of fluids more or less perfect (as
we use the expression) ; they receive new matter
under the influence of the same appetites ; and they
perfect or animalize it, and appropriate it, by similar
organs.
In all the more perfect animals we have a texture
of bones, constituting the skeleton, and giving form
and stature ; both bearing up the soft parts and
protecting them, and at the same time receiving
the influence, and adjusting the effects, of the con¬
tractile parts of the body : for the bones are moulded
with a regard to the motions to be performed, and
their shapes give a direction to the efforts of the
muscles.
The muscles constitute, properly, the fleshy part
of the body. They consist of a fibrous texture, and
are possessed of a peculiar animal and living power
of contraction: in them, motion is originated by
13
introduction.
3
the influence of nerves ; and by their operation on
the bones, the motions and agency of the body are
produced. 1
The nerves are like white cords, which are every
where traceable through the body, where sensibility
and motion can be perceived. They extend betwixt
the brain and the muscular frame, combine the
muscles in their actions on the bones and joints, and
convey to them the influence of the will.
But these muscles and nerves have powers peculiar
to them as living parts. All living properties are
continued and propagated through the influence of
the circulating blood: so that, although in the
nerves, muscles, and bones, we see all that is neces¬
sary to the mechanism of the frame, we find every
where accompanying them, arteries, veins, and lym¬
phatics, which are necessary to their constitution as
living parts.
To knit the bones together, and form the articula¬
tions, to be a bed and proper support for the muscles,
to constitute a general bond of union betwixt bones,
muscles, nerves, and blood-vessels—a certain cellular
texture is necessary. This common cellular sub¬
stance extends over the whole frame, unites the
rudest parts, as the bones, and sustains the most
delicate vessels, and such as are not visible to the
naked eye; it constitutes, therefore, a very large
proportion of the body, and is common to all
animals.
Still, in what is here described, we have only the
common textures of the frame of animal bodies ; and,
suppose them so constituted and possessed of their
endowments, to feel or suffer, to re-act and to move
symmetrically, how are these powers to be continued,
and the delicate textures to be preserved ? This con¬
sideration leads to the second division of the Anatomy,
b 2
introduction.
the viscera ; the organs which are for the reception
and assimilation of new matter.
To the circumstances of volition and locomotion,
is owing the necessity for an alimentary canal. The
vessels of vegetables, extended in their roots, draw
nourishment from the soil; but animals must have
these vessels and absorbing mouths internal, and the
nutritious matter conveyed to them through an
intestinal canal. In this canal, various processes are
performed, suiting the contained matter to its new
condition, and fitting it to be received into the living
vessels, and gradually assimilating it to the condition
of the circulating blood. In man, the food requires
no preparation but of mastication, and is directly
carried into a digesting stomach. Digestion is the
first and the most essential change wrought upon the
food : after that it is sent into the intestines, and
subjected to the operation of certain secreted fluids,
which separate, and, as it were, refine off the pure
and nutritious fluid. It is then subjected to the
absorbent mouths of the lacteals of the intestines, by
a process as curious as any to be observed in the
animal functions, and incapable of being explained
on the common principles of fluids acting on dead
matter out of the body. By the lacteals, the fluid
destined to supply the waste of the body is carried
into the circulating system.
The circulating system consists of heart, arteries,
and veins, a set of tubes continuous throughout, which
transmit the blood through the whole body. The
blood is sent outward by the arteries, and returns by
the veins, and thus moves in a continual stream,
urged on by the contraction of the containing tubes
and cavities.
In animals which have a circulation, the blood is
a vehicle which is constantly receiving from the
11
Introduction.
5
alimentary canal, what it furnishes to all parts of the
body for their growth. It is in its distribution to
the extremities of the arteries that it effects those
purposes of nutrition. In the very lowest animals,
some physiologists have persuaded themselves that
the vessels carry the fluid directly from the stomach
to the parts of the frame, to nourish them. But in
the more perfect animals, we know that it is not so.
The new fluid which has come from the organs
of digestion and assimilation, is not fit for the pur¬
poses of nutrition until it has suffered the influence
of the lungs. Nor is the blood which returns from
the body by the veins, capable of sustaining the
endowments or properties which distinguish the dif¬
ferent textures as living parts, until it be submitted
to the same operation.
Lungs, therefore, are an essential part of the or¬
ganic functions of all living beings. Vegetables, and
those animals which have no true circulation, respire
through the whole of their surface, or they have the
air admitted into the interior of their bodies through
different foramina, and by air-vessels, which accom¬
pany the blood-vessels in their distribution to the
body. It is a beautiful display, to see minute tubes
distributing air and mingling with those carrying
blood, as if they were as necessary to the health and
exercise of the living properties, as the blood-vessels
themselves. And so it is proved by the survey of
animated nature, to be in some way essential to the
existence of life, that the blood and the pure air shall
mutually influence each other.
In the more perfect animals, the lungs admit the
air into contact with the blood. They consist of
innumerable cells, having connexion with the wind¬
pipe or trachea, and by the muscular apparatus of
the chest or thorax, these cells are expanded and
b S
INTRODUCTION.
compressed alternately; so that the atmospheric
air is permitted to press or sink into these cells
in inspiration, and is again discharged in expira¬
tion. To the cells of the lungs, a grand division
of the circulating system of vessels is transmitted:
arteries carrying the blood to them, and veins return¬
ing that blood again to the heart. And by means of
these vessels the blood in the lungs is exposed to
the influence of the atmospheric air, and through its
influence it is purified.
This is the meaning of what is termed the double
circulation, and the double heart; for in the higher
and warm-blooded animals, there is a heart, consisting
of two cavities, for receiving the blood from the body
and transmitting it to the lungs, and there is another
heart of two cavities for receiving the blood from the
lungs and transmitting it to the body. These four
cavities are tied together by the interlacement of
their muscular fibres ; and their walls, being animated
by the same nerves, are in every respect combined,
and subject to the same excitement: so that as the
principal force of circulation is in the heart (for so
we call the union of the four cavities), the circula¬
tion in the body and the circulation in the lungs
are regulated by the heart's excitement, and always
correspond.
The air respired must contain oxjgejj, or vital
air ; the air returned from the lungs is loaded with
carbonic acid gas. The blood which had received the
operation of the oxygen upon it was venous, dark-
coloured, and unfit for the offices of life; but, on
returning from the lungs, it has parted with its car¬
bon,—it has become purer in colour j it is the bright
vermilion-coloured blood which, from its being trans¬
mitted through the body by the arteries, is called
arterial blood.
INTRODUCTION.
7
No animals respire by a particular organ except
those that have a real circulation of the blood ;
because, in them, the heart and vessels are so ordered,
that no blood is transmitted to the body, unless the
whole or part has been subjected to the offices of the
lungs and purified, and made capable, not merely of
conveying the nutriment and material of the bodily
frame, but also of supporting the vital energies,
whatever these may be. Whether it is the nerve which
has to feel, or the muscle to contract, no quality of
life can be long supported in the organ without the
supply and actual contact of the pure or arterial
blood.
In this introductory survey of the animal oeconomy,
we perceive that the functions may be divided into
three distinct orders.
We perceive that if animals required no supply, and
if they held an independent existence, the faculties
of sensation and motion would suffice, and nerves
and muscles would constitute the whole active frame.
These are the functions which anatomists call the
animal functions, by which we might suppose the
lower properties of our nature were meant ; but the
term is used in contra-distinction to vegetable life,
which enjoys neither sense nor motion.
In opposition to the animal functions, are the vital
functions, by which are meant, those which serve
for the preservation and renovation of the machine j
such as the offices of digestion, absorption, circula¬
tion, respiration, and the excretions.
Finally, the duration of each individual is defined J
and limited. There is a continual change and renova¬
tion of the frame, an intestinal or internal motion, a
separation and an absorption of its particles, by which
the body is ever newj but the life, the active prin¬
ciple, suffers change in infancy, youth, maturity, and
b 4
INTRODUCTION.
the debility of age and death. Such is the law of
animal existence. By which we see the necessity of
a system of superadded parts, and a third order of
functions : organs of generation, by which the indi¬
viduals that perish, are replaced by others, and by
which the existence of each species of animals is
maintained.
On the whole, and surveying what is common to
all animals, we perceive,—and all men who do not
allow their passions to interfere with their philoso¬
phical opinions must acknowledge,—that there is a
principle of life which holds those bodies that enjoy
it, subjected to a law different from that which
governs inanimate matter; and that the principal
character of this power is to withdraw the bodies it
animates, from the influence of those mere chemical
affinities, to which, from the multiplicity of their
component parts, their mixture, moisture, and tem¬
perature, they would have a strong tendency, and to
which they are immediately exposed on death, and
whereby their textures are reduced to their original
elements.
9
OF THE SKELETON.
The skeleton is the assemblage of bones which
sustains the soft parts, and gives form to the human
body. The bones may be contemplated in their
three offices: — 1. As columns under the weight of
the parts ;—2. As levers on which the muscles act,
to give activity and locomotion ; — and, 3. As a
covering and protection to the softer and more deli¬
cate organs. In all the higher links of the chain of
animal existence, there is a texture resembling the
composition of bone, to sustain or protect the soft
parts. In the corals, we may see a skeleton common
to the whole family. In testacea it is an external
shell, a calcareous foliated texture for their pro¬
tection. In creatures that creep, the muscles are
attached to their skin ; while in the Crustacea there
is a calcareous crust, which is at once skin and skele¬
ton, since the shell is in distinct parts, and articu¬
lated, and these parts have the muscles inserted into
them. In reptiles and fishes, there is an internal
system of bones, or a true skeleton. The peculiarity
of their skeleton is not merely in the form and
arrangement of the bones, but in their possessing
more elasticity than belongs to the skeleton of birds
and quadrupeds.
The thing most admirable in the composition of .
the skeleton, is the relation of its parts ; the manner
in which all its parts are cast at once, forming a
system which, in our methods of proceeding, we are
10
OF THE SKELETON.
apt to forget. For, studying the individual bones
with great minuteness, we neglect the relation which
is established betwixt all the parts of the skeleton of
any one animal.
If the reader turn to the Review of the Skeleton,
he will perceive that a system pervades all animated
nature ; but in the mean time it may be more proper
for him to consider the structure of one of the long
bones.
That the bones, which form the interior of animal
bodies, should have the most perfect shape, com¬
bining strength and lightness, ought not to surprise
us, when we find this in the lowest vegetable pro¬
duction.
In the sixteenth century, an unfortunate man who
taught medicine, philosophy, and theology, was
accused of atheistical opinions, and condemned to
have his tongue cut out, and to suffer death. When
brought from his cell before the Inquisition, he was
asked if he believed in God. Picking up a straw which
had stuck to his garments, " If," said he, " there was
nothing else in nature to teach me the existence of a
Deity, even this straw would be sufficient!"
A reed, or a quill, or a bone, may be taken to prove
that in Nature's works strength is given with the
least possible expence of materials. The long bones
of animals are, for the most part, hollow cylinders,
filled up with the lightest substance, marrow ; and in
birds the object is attained by means (if we may be
permitted to say so) still more artificial. Every one
must have observed, that the breast-bone of a fowl
extends along the whole body, and that the body is
very large compared with the weight: this is for the
purpose of rendering the creature specifically lighter
and more buoyant in the air ; and that it may have a
surface for the attachment of muscles, equal to the
exertion of raising it on the wing. This combination
of lightness with increase of volume, is gained by air-
cells extending through the body, and communicating
by tubes between the lungs and cavities of the
OF THE SKELETON.
11
bones. By these means, the bones, although large
and strong, to withstand the operation of powerful
muscles upon them, are much lighter than those of
quadrupeds.
The long bones of the human body, being hollow
tubes, are called cylindrical, though they are not
accurately so, the reason of which we shall presently
explain ; and we shall, at the same time, show that
their irregularities are not accidental, as some have
imagined. But let us first demonstrate the advantage
which, in the structure of the bones, is derived from
the cylindrical form, or a form approaching to that
of the cylinder. If a piece of timber supported on
two points, thus —
its solidity and resistance to compression ; the lowest
part B, on the other hand, resists by its toughness,
or adhesive quality. Betwixt the portions acting in
so different a manner there is an intermediate neutral,
or central part, C, that may be taken away without
materially weakening the beam, which shows that a
hollow cylinder is the form of strength. The author
lately observed a good demonstration of this: —a
large tree was blown down, and lay upon the ground;
to the windward, the broken part gaped ; it had been
torn asunder like the snapping of a rope : to the lee¬
ward side of the tree, the fibres of the stem were
crushed into one another and splintered ; whilst the
central part remained entire. This, we presume, must
be always the case, more or less. And here we may
take the opportunity of noticing why the arch is the
form of greatest strength. If this transverse piece of
timber were in the form of an arch, and supported at
bear a weight upon it,
it sustains this weight
by different qualities in
its different parts. For
example, divide it into
three equal parts (A, B,
C): the upper part A
supports the weight by
OF THE SKELETON.
the extremities, then its whole thickness, its centre,
as well as the upper and lower parts, would support
weight by resisting compression. But the demonstra¬
tion may be carried much farther to show the form of
strength in the bone. If that part of the cylinder
which bears the pressure be made more dense, the
power t>f resistance will be much increased ; whereas,
if a ligamentous covering be added on the other side,
it will strengthen the part which resists extension:
and we observe a provision of this kind in the tough
ligaments which run along the vertebras of the
back.
When we see the bone cut across, we are forced
to acknowledge that it is formed on the principle of
the cylinder; that is, that the material is removed
from the centre, and accumulated on the circum¬
ference, thus *—
We find a spine, or ridge, running
along the bone, which, when divided
by the saw in a transverse direction,
exhibits an irregularity, as at A.
The section of this spine shows a
surface as dense as ivory, and it is,
therefore, much more capable of
resisting compression than the other
part of the cylinder, which is common bone. This
declares what the spine is; and those anatomists must
be wrong who imagine that the bone is moulded by
the action of the muscles, and that the spine is a
mere ridge, arising by accident among the muscles.
It is, on the contrary, a strengthening of the bone
* See Munro's Works, p. 45. " Since the united force of all
the fibres is to be regarded as resisting at a distance from the
centre of motion equal to the semi-diameter, it follows that the
total resistance of all these fibres, or the strength of the bone,
is proportional to its semi-diameter, and consequently to its
diameter." This proposition has been demonstrated mathemati¬
cally, by Dr. Porterfield, in the Medical Essays of Edinburgh,
vol. i. art. 10. b
OF THE SKELETON.
in the direction on which the weight bears.* If* we
resume the experiment with the piece of timber, we
shall learn why the spine is harder than the rest of
the bone. If a portion of the upper part of the timber
be cutaway, and a harder
| wood inserted in its place,
the beam will acquire a
new power of resisting
fracture, because, as we
have stated, this part of
the wood does not yield
but by being crushed, and the insertion of the harder
portion of wood increases this property of resistance.
With this fact before us we may return to the
examination of the spine of bone. We see that it is
calculated to resist pressure, first, because it is farther
removed from the centre of the cylinder; and,
secondly, because it is denser, to resist compression,
than the other part of the circumference of the
bone.
This explanation of the use of a spine upon a bone
gives a new interest to osteology. The anatomist
ought to deduce from the form of the spine the
motions of the limb ; the forces bearing upon the
bone, and the nature and the common place of frac¬
ture : while, to the general enquirer an agreeable
process of reasoning is introduced in that depart¬
ment, which is altogether without interest when the
" irregularities " of the bone are spoken of, as if they
were the accidental consequences of the pressure of
the flesh upon it.
Although treating of the purely mechanical prin¬
ciple, it is, perhaps, not far removed from our proper
object to remark, that a person of feeble texture and
indolent habits has the bone smooth, thin, and light;
but that Nature, solicitous for our safety, in a manner
* As the line A B extends farther from the centre than B C,
on the principle of a lever, the resistance to transverse fracture
will be greater in the direction A B than B C.
OF THE SKELETON.
which we could not anticipate, combines with the
powerful muscular frame a dense and perfect texture
of bone, where every spine and tubercle is completely
developed. And thus the inert and mechanical pro¬
visions of the bone always bear relation to the mus¬
cular power of the limb, and exercise is as necessary
to the perfect constitution of a bone as it is to the
perfection of the muscular power. Jockies speak
correctly enough, when they use the term " blood
and bone" as distinguishing the breed or genealogy
of horses ; for blood is an allowable term for the
race, and bone is so far significant, that the bone
of a running horse is remarkably compact com¬
pared with the bone of a draught horse. The
reader can easily understand, that the span in
the gallop must give a shock in proportion to its
length ; and, as in man, so in the horse, the greater
the muscular power, the denser and stronger is the
bone.
The bone not being as a mere pillar, intended to
bear a perpendicular weight, we ought not to ex¬
pect uniformity in its shape. Each bone, according
to its place, bears up against the varying forces that
are applied to it. Consider two men wrestling
together, and then think how various the properties
of resistance must be : here they are pulling, and
the bones are like ropes; or again, they are writhing
and twisting, and the bones bear a force like the
axle-tree between two wheels ; or they are like a
pillar under a great weight; or they are acting as a
lever.
To withstand these different shocks, a bone con¬
sists of three parts, the earth of bone (phosphate
of lime) to give it firmness; Jibres to give it
toughness ; and cartilage to give it elasticity.
These ingredients are not uniformly mixed up
in all bones ; but some bones are hard, from the
prevalence of the earth of bone ; some more
fibrous, to resist a pull upon them ; and some more
elastic, to resist the shocks in walking, leaping, &c.
OF THE SKELETON.
But to return to the forms:—Whilst the centre of
the long bones is, as we have stated, cylindrical, their
extremities are expanded, and assume various shapes.
The expansion of the head of the bone is to give a
greater, and consequently a more secure surface for
the joint, and its form regulates the direction in
which the joint is to move. To admit of this en¬
largement and difference of form, a change in the
internal structure of the bone is necessary, and the
hollow of the tube is filled up with cancelli, or lattice¬
work. These cancelli of the bone are minute and
delicate, like wires, which form lattice-work, extend¬
ing in all directions through the interior of the
bone, and which, were it elastic, would be like a
sponge. This texture of the bone permits the outer
shell to be very thin, so that whilst the centres of the
long bones are cylinders, their extremities are of a
uniform cancellated structure. But it is pertinent to
our purpose to notice, that this minute lattice-work,
or the cancelli which constitute the interior structure
of bone, have still reference to the forces acting on
the bone ; if any one doubts this, let him make a
section of the upper and lower ends of the thigh¬
bone, and let him inquire what is the meaning of the
difference in the lay of these minute bony fibres, in
the two extremities ? He will find that the head of
the thigh-bone stands obliquely off from the shaft,
and that the whole weight bears on what is termed
the inner trochanter; and to that point, as to a
buttress, all these delicate fibres converge, or point
from the head and neck of the bone.
There is another circumstance of more practical im¬
portance, connected with the difference of texture of
the bone in its diaphysis and epiphysis, that is, in its
centre and its extremities. Different effects will be
produced by violence ; for example, by gun-shot. A
musket-ball will sink into the head of the bone and
lodge there, or pass quite through it; whereas if it
strike the centre, it will split it up and break it into
twenty pieces. Of this the reader may find examples
OP THE SKELETON.
in the Museum of the College of Surgeons of Edin¬
burgh, which specimens I took from the wounded at
Corunna and at Waterloo. It is probably owing to the
looser texture of the extremities of the long bones
that true necrosis does not take place in them, but
only in the diaphysis.
Some, with a singular unhappiness of disposition,
will contemplate the chain of animal existence, and
see in it only a mechanical principle of adherence to
a certain original type or model; and they have
more gratification in giving a catalogue of things
useless (that is to say, of parts, the beauty or useful¬
ness of which they do not comprehend), than of con¬
templating the whole, and allowing their minds to
receive that natural influence which the system of
nature is calculated to produce.
The four divisions of the upper extremity exist in
all the anterior extremities of the class mammalia. A
curious inspection of the gradations will prove that
parts dissimilar in form, are a new appropriation of the
same bones. In the fin of a whale we may recognize
the bones of the human hand. Strip the integuments
off* the anterior fin of the dolphin or porpoise, and
we recognize, somewhat disordered, a scapula,
humerus, fore-arm, and carpus, metacarpus, and
finger bones. It should surprise us less, that in the
wing of a bird we should see the bones of the
anterior extremity of a quadruped ; or recognize, in
the fine bones which stretch the membraneous wing
of a bat, the phalanges of the fingers. Although
there be no resemblance betwixt the outer form
of animals that walk, and those that fly, and
those that creep, yet in all of them the skeleton is
recognizable as the same system of bones, variously
modified.
But the question returns upon us,—can there be
an adaptation of parts better calculated to their end,
or more obviously designed, or better evidence of a
system pervading all nature, and that the whole has
been cast out at once from a power omnipotent ?
OF THE SKELETON.
17
There is not a more curious proof of adaptation of
the texture of the skeleton to the condition and
habits of animals, than we have in the bones of
birds and fishes. In the former, as we have said,
the dimensions, and consequently the strength, are
increased without adding to the weight, by admitting
a communication betwixt the lungs and the cavities
of the bones, by which air is admitted into them.
In fishes, the bones are light, not only by having
a lesser quantity of earth in their composition, but
by having spermaceti or oil deposited in their
cavities. In the spermaceti whale, the head is
kept buoyant, and the blow-holes above the water,
by a large quantity of the spermaceti lodged in the
head.
The bones of the human skeleton have been
divided into the flat and cylindrical bones. It is
incorrect, and therefore unscientific. Their forms
are too much varied to admit of this sort of arbitrary
division. There can be no other division of the
skeleton, than into, 1. The bones of the trunk.
2. The bones of the extremities. 3. The bones of
the head.
The bones are united in a manner varying with
their forms and uses. They are immoveably joined immobiiis
together, by having their processes fixed into cor- JZVsyLr-
responding cavities, like cabinet-work; or, where throsis; viz.
the texture of bone is delicate, they are simply laid Harmo-
together, and a line marks their union ; j, or they nia.
are laid over each other, and spliced together ; or sg^amoZ.
conical processes are, in a manner, inserted into 4. Gompho-
corresponding cavities, like a nail; or the bones **■ ,
„ r ' ■ i , • i > • • i 5. Si/nchon-
are firmly joined, yet so as to give some elasticity, drosis.
and to take off the jar of contact, by intermediate
cartilage. Finally, the bones are constituted with a 6. Diarthro-
relation to free motion at their articulation: for
which purpose their extremities are covered with tura.
smooth cartilage, and joined by ligaments.
It is an interesting subject of study, to consider
the uses of the parts, and to observe with what
VOL. i. c
OF THE SKELETON.
felicity and curious skill (so would we express our¬
selves of things of human invention) the strength,
forms, and processes of the bones are adapted.*
* The young student, before entering on the demonstration of
the bones, should make himself familiar with the meaning of
such terms as the following : Fovea, Fossa, Cella, Sinus, Fissura,
Sulcus, Foramen, Meatus, Cervix, Condylus, Apophysis, Spina,
Crista, Stylus, fyc. Let him look up these words in his dictionary.
For although this anatomy is written with a desire to substitute
the full and pure English description for the barbarism of the
terms used in anatomical works, it is not always possible to avoid
the use of such terms, in describing the infinite varieties in the
form of bones. Indeed, the student ought to know these terms;
and yet in communication and consultation it shews a better
educated man to prefer the English language, if it can be made
sufficiently descriptive.
g'SEgr } X -
v ^ , y, _ £ /. *■1 -/>. /^U^-Uuw;
'U i!^ 'ia-tffiL iTL~&4*s£ . / 19
& *4 0*4/1*^1^^. — ■ /
< /
. /a t j/ / <*> ,
Owts*~ fin &.i*
. -'S „ /<
/-<& •"• *'•' '*v 2
OF THE TRUNK.
the bones of the spine, pelvis, and thorax.
The demonstration of the bones should begin with
those of the spine,, as it is the centre of muscular
action, and the part of most common relation; for
the spine is placed upon the arch of bones which form
the pelvis, and supports the head, and is at the same
time the bond of union of the bones of the thorax or
chest.
The bones of the trunk consist of these : the chain
of bones forming the vertebral column or spine ; the
bones of the pelvis ; the ribs; and the sternum or
breast-bone.*
of the spine.
The spine is so named from certain projecting Uses of the
points of each bone, which, standing outwards in spme'
the back, form a continued ridge ; and the appear¬
ance of continuity is so complete, that the whole
ridge is named spine, which, in common language,
is spoken of as a single bone. This long line consists
* The reader may peruse the dissertation on the formation and
growth of bone, before studying the forms and processes of the
skeleton. But as the subject is abstruse, it has been (in this
edition) introduced at the end of the anatomy of the bones.
C 2
20
OF THE TRUNK.
of twenty-four distinct bones, named vertebras, from
the Latin vertere, to turn, lhey 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 ; 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 inconsistent 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 quickly in all directions, yet so steady withal,
as to contain and defend the most material and the
most delicate part of the nervous system.
Classifiea- The vertebras are arranged according to the neck,
^4 vertebrae back, and loins, and the number of them corresponds
Five of the with the length of these divisions. The vertebras of
loins. 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 performing the chief motions of
Twelve of the trunk. The vertebrae of the back are twelve in
the back, 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 connexion with the ribs : this
is, therefore, the steadiest part of the spine ; a very
Seven of limited motion only is allowed. The vertebras of
the neck. ,
the neck are seven m 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 vertebras 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 changed, according to the
proportions of the body ; for, where the loins are
of the trunk.
21
long, there are six vertebrae of the loins, and but
eleven in the back ; or the number of the pieces in
the back is sometimes increased to thirteen ; or the
neck, according as it is long or short* sometimes has
eight pieces, or sometimes only six. However, these
varieties are very rare.
The general form, processes, and parts of the s^^etjond0ef"
vertebrae are best exemplified in a vertebra of the a vertebra,
loins ; for in it, the body is large, the processes
are right-lined, large, and strong ; the joint is
complete, and all its parts are very strongly marked.
Every vertebra consists of a body, which is firm, for
supporting the weight of the body, and hollow
behind, for transmitting the spinal marrow : of two
articulating processes above, and two below, by which
it is jointed with the bones which are above and
below it: of two transverse processes, which stand
out from either side of the bone, to give hold and
purchase to those muscles which turn the spine ;
and of one process, the spinous process, which
stands directly backwards from the middle of the
bone: and these processes being felt in distinct
points all the way down the back, 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 Particular
and spongy bone ; it is circular before, and flat upon Df thTbody.
the sides. It is hollowed into the form of a crescent shape,
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 The harder
ring above and below, as a sort of defence ; and nng'
within the ring, the body of the vertebra is hollowed ^"vTand
out into a sort of superficial cup, which receives below,
the ligamentous substance, by which the next ver¬
tebra is joined to it; so that each vertebra goes upon
a pivot, and resembles the ball and socket joints.
And in many animals it is distinctly a joint of this
kind.
On the fore and back part of the body of the Foramina.
c 3
22
of the trunk.
Tlie arch.
The notch.
The articu¬
lating pro¬
cess,
called also
oblique.
The spin¬
ous pro¬
cesses.
vertebra are several holes, which are for the trans¬
mission 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 vertebras 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, the in¬
tervertebral substance, which forms a more fixed, and
rather an elastic joining; and they are united again
by the articulating processes, which make a very
moveable joint of the common form. The arti¬
culating processes are sometimes named oblique
processes, because they stand rather obliquely. The
upper ones are named the ascending oblique pro¬
cesses, and the two lower ones are named the
inferior or descending oblique processes.
The spinous processes are those which project
directly backwards, whose points form the ridge of
Ihese toramina enlarge in the beginning of the scrofulous
inflammation of the bone.
OF THE TRUNK.
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 powerful lever to work
their effects by. The spinous processes, then, are
for the insertion of these muscles, which extend and
raise the spine, and for the attachment of a ligament
which runs from point to point in the whole length
of the spine, and which checks the bending of the
trunk forward.
The TRANSVERSE PROCESSES Stand out from the Transverse
sides of the arms or branches (named crura) which Processes-
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 vertebrae, as there is no
provision for much lateral motion in the lower part
of the spine; but the muscles which are implanted
into these are more commonly used in assisting those
which extend and raise the spine.
These, and all the processes, are more distinct,
prominent, and strong, more direct, and larger in
the loins, and more easily understood^ than in the
vertebras of any other class. But this prepares only
for the description of the individual vertebra, where
we find a variety proportioned to the various offices
and to the degrees of motion which each class has
to perform.
Of the VERTEBRiE OF THE LOINS. 1 have chosen Peculiar^
to represent the general form of a vertebra, by
describing one from the loins, because of the distinct- vertebra,
ness with which all its parts are marked. In the
lumbar vertebras, the perpendicular height of the
body is comparatively less, the intervertebral sub-
c 4
of the tiiunk.
stance is thicker than in the other parts of the spine,
and the several processes stand off from each other
distinct and clear ; all which are provisions for a
Spinal canal freer motion in the loins. The arch of the lumbar
larger. vertebra is wider than in the back, to admit the
looser texture of the spinal marrow.
the body The body of a lumbar vertebra is particularly
broad.and large, thick, and spongy, and its thin outer plate is
perforated by many arteries going inwards to nourish
this spongy substance of the bone. The length of
the body is about an inch, and the intervertebral
cartilage is very considerable ; so that the vertebra?
of the loins present to the eye, looking from within
the body, a large, thick, and massy column, fit for
supporting so great a weight.
the spin- The spinous process is short, big, and strong. It
short.roccss runs horizontally and directly backwards from the
arch of the spinal marrow. It is flattened, and about
an inch in breadth ; and it is commonly terminated
by a lump or knob, indicating the great strength of
the muscles and ligaments which belong to it, and
the secure hold which they have.
Transverse The transverse process is longer and firmer than
•i. ' # o
rcct.ess the other vertebra?; it goes out laterally and hori¬
zontally, and is provided for the origins of powerful
muscles. We find the spinous process divided into
two unequal parts by a spine running from the inferior
articulating process ; in the same manner we see the
transverse process divided by a ridge extending from
the superior articulating process.
Artkuiat- The articulating processes of the lumbar ver-
perpendicu-
tebrag stand so directly upwards and downwards,
lar- that the name of oblique processes cannot be applied
here. They are tuberculated and strong, partaking
of the peculiarity which marks the general form of
those vertebra? of the loins.
dor'at ^ the vertebrae of the back.—The character
vertebra. of the vertebras of the back is directly opposite to
that of the loins. The bodies of the vertebra? are
smaller, though still large enough to support the
Body deep, great weight of the trunk ; but they are much deeper,
of the trunk.
<25
proportionably, than those of the loins, and their
intervertebral substance is thin, for there is little
motion here. The spinous processes in the vertebras spinous
of the back are very long and aquiline. They are f0r°^ss
broad at their basis, and very small or spinous at oblique,
their further end ; and in place of standing perpen- grooved'
dicularly 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 nearly touching the one
below, by which the motions of these vertebrae are
abridged; and the further to sustain the column,
there is a groove on the under surface of the spinous
process, which receives the superior edge of the one
below. The transverse processes are short and ti ansverse
knobby : in place of standing free and clear out, like |j[r0tfcet^s
those of the loins, they stand obliquely backward, backwards,
are trammelled and restricted from motion, by their
connection with the-ribs ; for the ribs are not merely impression
implanted upon the bodies of the dorsal vertebrae, on the
x jl * transverse
but they are further attached firmly by ligaments, process,
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. We get another mark by which the dorsal
vertebrae may be known : for each vertebra bears Two im-
two impressions of the rib which was joined to it, theTody °n
one on the flat side of its body, and the other on the
fore part of its transverse process. On the extremity
of each of these transverse processes, a tubercle
projects backward, giving advantage for the attach¬
ment of muscles. The articulating processes are so Articuiat-
short, that they can hardly be described as distinct "IfJs™"
projections, and they stand out so directly from the
transverse process, appearing as parts of it. The More
surfaces of these processes present more obliquity, oblliue-
and they are simpler in form, and smoother, than
those of the loins.
26
of the trunk.
We may distinguish the first vertebra of the back,
by its having the whole of the head of the rib im¬
pressed upon its side.
The 12th, or lowest dorsal vertebra, has also the
entire head of the rib impressed upon it, and it
has no articulating surface on the extremity of the
transverse process.
Of the vertebrae of the neck.—The vertebrae of
the neck depart still farther from the form of those
of the loins. The body is very small in all the ver¬
tebrae 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 inter¬
vertebral substance ; but the surfaces of the body
are flat or plain, and the articulating processes are
oblique, and make, as it were, one articulation with
the body ; for the lower surface of the body being
not hollow, but plain, and inclined forwards, and the
articulating processes being also inclined backwards,
Articuiat- and oblique, the two surfaces are opposed to each
jng process- 0t}ler . t]ie one prevents the vertebrae from sliding
cs oblique. 7 l ©
forwards, and the other prevents it from sliding
backwards, while a pretty free and general motion
spinous is allowed. The spinous processes of the neck are
bifurcated s^ortj and project directly backwards ; they are for
short, and' the insertion of many muscles, and therefore they
horizontal. are Sp]j^ all(j haye small tubercles on their extremi¬
ties. This bifurcation of the spinous process is not
absolutely peculiar to the cervical vertebrae ; for
sometimes, though rarely, the others are so : and it
is only in the middle of the neck that even they
are forked ; for the first vertebra is a plain ring, with
hardly any spinous process, because there are few
muscles attached to it; and the process of the last
vertebra of the neck is not bifurcated, so that it
tebnTo/the aPProaches to the nature of the dorsal vertebrae ; the
neck, the spinous process is long and aquiline, is depressed
Vprominens. towards the back, and is so much longer than
The first
and last
dorsal ver¬
tebra dis¬
tinguish¬
able.
Cervical
vertebras.
Their
bodies
small.
of the trunk.
the others, as to be distinguished by the name of
vertebra prominens.
The transverse processes of the neck are grooved Transverse
and bifurcated, because there are a great many small Elated;
muscles attached to them. But the most curious
peculiarity of the transverse processes is, that each
of them is perforated for the transmission of the perforated,
great artery, which is named vertebral artery,
because it passes through these holes in the vertebras
which form altogether a bony canal for the artery.
So that the character of these cervical vertebrae General
is, that they are calculated for much free motion ; character*
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 process,
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 vertebrae, except sometimes the
first and last, are perforated near their extremities
with the large hole of the vertebral artery.
ATLAS and VERTEBRA DENT ATA.—But
among these vertebrae of the neck, two are to be
particularly distinguished, as of greater importance
than all the rest; for though the five lower vertebrae
of the neck be ossified and fixed, if but the two
uppermost remain free, the head, and even the neck,
seem to move with ease.
The first vertebra is named atlas, perhaps because Atlas,
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 Wants the
vertebrae of the neck, for its processes are scarcely body"
distinguishable : it has no body, unless its two articu¬
lating processes are to be reckoned as a body : it is
no more than a simple ring; it has hardly any Spinous
spinous process j and its transverse process is long
28
OF THE TIIUNK.
and perforated, but not forked. On the upper
margin of the ring may be observed 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: in its place, the vertebra has a flat
surface looking backwards, which is smooth and
polished for the rolling of the tooth-like process;
Has a sharp there is also a sharp point rising perpendicularly
process^ upwards towards the occipital bone, and this point is
held to the edge of the occipital hole by a strong
Articuiat- ligament. The smooth mark of the tooth-like
mg surface 0 . n . , • i •
of the pro- process is easily found; and upon either side or it,
cessus den- there proiects a small point from the inner circle of
taliis. i • i -i t 11
Points of the ring : these two points have a ligament extended
artfuh?lent betwixt them, called the transverse ligament, which,
of the trans- . ' . . . © 7 '
verse liga- like a bridge, divides the ring into two openings;
ment. one ^jie smaHer, for lodging the tooth-like process,
embracing it closely ; the greater opening is for the
spinal marrow : the ligament 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
Origin of dies. On the inside and lateral part of the circle,
li^amen?1 ^ie or^n °f the lateral ligaments of the processus
dentatus may also be observed.
Articuiat- The articulating frocess may be considered as
mg surfaces. tjie bociy Gf 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
hoiwPper neck* The two upper articulating surfaces are oval,
oblique. 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
OF THE TRUNK.
29
towards its fellow. Now, by the obliquity 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 carries the first vertebra along with
it, moving round the tooth-like process of the den-
tatus. The articulation with the head is a hinge Forming
joint, in the strictest sense: it allows of no other condyles a
motion than that backwards and forwards; the hinge joint,
nodding motions are performed by the head upon
the atlas, the rotatory motions are performed by
the atlas moving along with the head, turning
upon the tooth-like process of the dentatus as on a
centre.
Now the upper articulating surfaces of the atlas
are hollowed, to correspond with the condyles of the
occipital bone, and to secure the articulation with
the head ; but the lower articulation, that with the The lower
vertebra dentata, being secured already by the tooth-
like process of that bone, no other property is smooth,
required in the lower articulating surfaces of the
atlas, than that they should glide with perfect ease ;
for which purpose they are plain and smooth ; they
neither receive nor are received into the dentata by
any hollow, but lie flat upon the surfaces of that
bone. It is also evident, that since the office of the Turning
atlas is to turn along with the head, it could not be °n the
o J dentata.
fixed to the vertebra dentata 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 No spinous
process j for the projection of a spinous process process-
must have prevented its turning upon the dentatus,
and would even have hindered, in some degree, the
nodding of the head; therefore the atlas has a simple
ring behind, and has only a small knob or button
where the spinous process should be, which is some¬
what irregularly notched. The transverse process Transverse
is not forked, but it is perforated with a large hole Pcrr-
for the vertebral artery ; and the artery, to get the artery.
30 OF THE TRUNK.
into the skull, makes a wide turn, lying flat upon
impression the bone, by which there is a slight hollow or
impression of the artery, which makes the ring of the
vertebra exceedingly thin. Sometimes, instead of
the groove for the artery, there is a perforation in
the ring.
But the form of the vertebra dentata best explains
these peculiarities of the atlas, and this turning of
the head.
The VERTEBRA DENTATA, ODONTOIDES,
or AXIS, is so named from its projecting point,
which is the chief characteristic of this bone.
When the dentata is placed upright before us, we
observe, 1. That it is most remarkably conical, rising
all the way upwards by a gradual slope to the point
of its tooth-like process. 2. That the ring of the
vertebra is very deep, that is, very thick in its sub¬
stance, and that the opening of the ring for trans¬
mitting the spinal marrow is of a triangular form.
3. That its spinous process, though short and thick,
short and ye^ projects beyond the level of the three spinous
strong. processes immediately below it; and that it is turned
much downwards, so as not to interfere, in any
its tooth- degree, with the rotation of the atlas. 4. That its
hke process, tooth-like process, from which the bone is named, is
very large, about half an inch in length ; very thick,
like the little finger ; that it is pointed; and that
from this rough point a strong ligament goes up¬
wards, by which the tooth is tied to the great hole of
Neck of the the occipital bone. We also observe a neck or collar,
process. or smaller part, near the root of the tooth-like pro¬
cess, where it is grasped by the transverse ligament
of the atlas ; while the point of the process swells
out a little above. We find this neck particularly
smooth ; for it is indeed upon this collar that the
in ^surfaces ^ead continually turns. And we see on each side
of this tooth-like process a broad and flat articulating
surface. These articulating surfaces are placed like
shoulders ; and the atlas, being threaded by the tooth¬
like process of the dentata, is set flat down upon the
4
of the
artery.
Dentata,
general
form.
Spinous
process
of the trunk.
31
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 insertion of
observe the roughness for the insertion of the lateral
ligaments, and its point is irregular where it is
grasped by the perpendicular ligament which comes
down from the occipital bone.
We may observe, that while the superior articu- Articuiat-
lating processes are horizontal, answering the pur-
pose of a body, the lower surface of this vertebra is
in all respects like the other vertebrae of the neck.
Of the SPINE generally.
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 outermost 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. Within this there
is the proper vagina or sheath which contains 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 inter¬
stice of each vertebra ; so that there are twenty-
five nerves of the spine, or rather fifty nerves,
twenty-five being given towards each side ; these
nerves pass each through an opening or small hole
in the general sheath ; there they pass through the
interstice of each vertebra ; so that there is no hole
in the bone required, but the nerve escapes by going
under the articulating process. This, indeed, is
OF THE TRUNK.
converted into something like a hole, when the two
contiguous vertebrae are joined to each other.
The bodies of the vertebrae are somewhat pecu¬
liar in structure, being light and spongy bones,
covered with a thin cortex : and it is from these
circumstances that they are very liable to scrofulous
caries.
The INTERVERTEBRAL SUBSTANCE.—
The intervertebral substance is that which is in¬
terposed betwixt the bodies of two adjoining ver¬
tebrae, and which is (at least in the loins) nearly
equal in thickness to 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, gradually softer towards the centre, and
with the rolled edges as if cut obliquely into a
sort of convex. The cut edges are thus turned
towards the surface of the vertebra, to which
each intervertebral substance belongs: it adheres
to the face of each vertebra, and it is confined by
a strong ligament all round ; and this substance,
though it still keeps its hold on each of the two
vertebrae to which it belongs, though it permits no
true motion of one bone on another, but only by
twisting of its substance, yields, nevertheless, easily
to whichever side we incline, and it 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 pro¬
perties indeed are best explained by its uses; for,
in the bendings of the body, it yields in a very
considerable degree, and rises 011 the moment that
the weight or the force of the muscles is removed.
In leaping, in shocks, or in falls, its elasticity pre¬
vents any harm to the spine, while other less im-
0
OF THE TRUNK.
portant joints are luxated and destroyed; and it
gives to the whole column that fine elasticity which
guards the head from sudden shocks, and the brain
from vibration.
Since pressure, in length of years, shortens the
fore part of the column of the spine, and makes
the body stoop, any undue inclination to either
side will cause distortion : the substance 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 but with
great difficulty and by exercises continued for a long
time : this distortion is peculiarly apt to happen 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 always on one arm
by a negligent or awkward nurse, will cause in time
a distortion.
We are now qualified to understand the motions
of the vertebra?, and to trace the degree of motion
in each individual class. The degrees of motion vary
with the forms of the vertebrae, 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 dentatus : all the lower
vertebrae 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 dorsal vertebrae are the most limited in their
movements, bending chiefly forwards by the yielding
of their intervertebral substance. The vertebras ol
the loins again move largely, for their interver¬
tebral substance is deep, and their processes less
entangled. To perform these motions, each vertebra
VOL. I. n
of the trunk.
has two distinct joints, as different in office as in
form : first, each vertebra is fixed to those above
and below by the intervertebral substance, which
adheres so to each that there is no true motion :
there is no turning of any one vertebra upon the
next; but the elasticity of the intervertebral sub¬
stance 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 com¬
mon nature with the other joints of the body, for
the articulating processes are faced with cartilage,
surrounded with a capsule, and lubricated with
synovia. 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 car¬
tilages, which yield to the motion of the ribs, and
return again when the muscles cease to act.
Each rib, then, is characterised by these mate¬
rial parts : a great length of bone, at one end of
which there is a head for articulation with the ver¬
tebras, and a shoulder or knob for articulation
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.
* See further of the Spine, in the Review of the Skeleton.
of the trunk. 35
The ribs are twelve in number, according to the 9lassifiea'
number of the vertebra? in the back, of which rlbs;°f "K
seven are named true ribs, because their cartilages Seven true,
join directly with the sternum, and these are the
preservers, the custodes, as protecting the heart;
and five are named false ribs, because their Car- Five false,
tilages are not separately 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 .Tvf,°.float-
another distinction, viz. that the last rib, and com- Hlg 11 >s
monly 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 form
• fl&t
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 Twisted-
by either end, and twisted betwixt the hands :
the meaning of which is, to accommodate the
flatness of the rib to the form which the thorax
assumes in all its degrees of elevation ; for when
the rib rises, and during its rising through all the
degrees 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 Upper edge
and cutting at its lower edge ; and its lower edge rounded-
seems double ; for there is a groove, which in some A grooveon
measure gives security to the intercostal artery and ^ower
nerve.
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 The head
small articulating surface ; but that smooth sur- ardcufating
face is double, or looks two ways. For the head surfaces,
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 ver¬
tebrae ; all the vertebrae, except the first and last,
D 2
of the trunk.
bear the mark of two ribs, one above, and one be¬
low. The mark of the rib is on the edge of either
vertebra, and the socket may be said to lie in the
intervertebral substance betwixt them.
cervix. 2. The neck of the rib is a smaller part, imme¬
diately before the head. Here the rib is particu¬
larly small and round.
T ubercle. 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
Articulat- process of the vertebra below. These two articula-
trfnlversehe tions have each a distinct capsule or bag : each is
process. a very regular joint; and the degree of motion
of the rib, and direction in which it moves, may
be easily calculated from the manner in which
it is jointed with the spine ; for the two articu¬
lating 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 vertebra,
and with its transverse process, are in one line
and form as if but one joint; so that the rib being
fixed obliquely, and at one end only, that end con¬
tinues firm, except in turning upon its axis: the
two heads roll upon the body of the vertebrae, and
upon the transverse process ; and so its upper end
continues fixed, while its lower end rises or falls;
and as the motion is in a circle, the head being
the central point, moves but little, while the lower
end of the rib has the widest range.
a second. 4. Just above the second articulating surface
tubercle. there is a second turbercle, which has nothing to
do with the joints, but is intended merely for the
attachment of the ligaments and muscles from the
spine which suspend and move the rib, and for the
attachment of the anterior slips of the longissimus
dorsi muscle.
Ti.e angre. ^ The angle of the rib is often mentioned, be¬
ing a common mark for the place of surgical oper¬
ations. There is a flatness of the thorax behind,
forming the breadth of the back ; the sharpness
where this flatness begins to turn into the round-
OF THE TRUNK. 37
ness of the chest is formed by the angles of the
ribs. Each rib is round in the place of its head,
neck, and turbercles : it grows flatter a little, as it
approaches the angle: but it is not completely
flattened till it has turned the angle which is the
proper boundary betwixt the round and the flat
parts of the rib ; into these angles of the ribs the
sacro-lumbalis is inserted. This anatomy of the Kecapituia-
ribs is sufficiently simple, but it is not equally easy tlon ofthe
S _ r > M J J anatomy ot
to observe how it bears on the practice or surgery, the rib.
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 lan¬
guage of surgeons, to know these parts, viz. the
head of the rib ; the turbercle, or second articu¬
lating surface ; the angle, or turning forward of
the rib; the upper round, and the lower sharp
edge ; and especially to remember the place and
the dangers of the intercostal artery. It is, how¬
ever, 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. The ribs
increase in the obliquity of their position from
the highest to the lowest, and their anterior ex¬
tremities expand, and are more distant from each
other. There are some peculiarities in individual. Pecuiiati-
ribs, the chief of which are these: the length of *-edsu°|
the rib is increasing from the first to the seventh,
but again decreases from the seventh to the twelfth ;
the curve of the ribs gradually decreases from the
first to the last, the first being exceedingly short
and circular, the lower ones longer, and almost
right lined, making a small portion or segment
of a large circle; so that the thorax is altogether
of a conical shape, the upper opening so small, as
just to permit the trachea, oesophagus, and great
vessels to pass ; the lower opening so large, that
it equals the diameter of the abdomen: the first
rib is consequently very short; it is thick, strong,
and of a flattened form ; of which flatness one face
d 3
38
OF THE TRUNK.
looks upwards, and another downwards, and the
great axillary artery and vein lie upon its flat upper
surface. We do not see any groove on the lower
surface for the intercostal artery. It is also par-
ticularly circular, making more than half a circle
from its head to the extremity where it joins the
sternum ; it has, of course, no angle, 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 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 vertebra only, while all the others have
theirs implanted betwixt the bodies of two ver¬
tebras. And there is this further difference, that
in the eleventh and twelfth ribs there are no
tubercles for the articulation with the transverse
processes. The cartilages of the ribs become
longer as they descend and approach nearer to
each other ; they complete the form of the thorax,
and form all the lunated edge of that cavity; and
it is from this cartilaginous circle that the great
muscle of the diaphragm has its chief origin,
forming the partition betwixt the thorax and the
abdomen. The farther end of each rib swells out
thick and spongy, and has a small socket for lodg-
sockctin ing the cartilage; for these cartilages are not joined,
t.xtremitrior the intervertebral substances, with their "bones:
of the rib, but there is a sort of joint, very little moveable
cartilage'0 indeed, 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,
of the trunk.
39
and sixth ribs rise upwards, in proportion to their
distance from this central one. The first fiye ribs
have independent cartilages. The eighth, ninth,
and tenth ribs run their cartilages into the carti¬
lage of the seventh rib. And the eleventh and
twelfth ribs have their cartilages small, unconnect¬
ed, and floating loose.
By the motion of the ribs, the thorax is alter- Motion of
nately dilated and diminished in capacity, the lungs the nbs
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 motion enlarges and diminishes the
diameter of the thorax, from the spine to the ster¬
num ; this enlarges the lateral diameter of the tho¬
rax. The importance of attending to the motion
of the ribs is obvious in practice ; for when the
rib is broken, the ends jar and rub against each
other, in consequence of the anterior extremity
moving through a greater space than the posterior;
and the business of the surgeon is to interrupt this.
Besides, the fracture of the rib, most commonly of
little consequence, is sometimes attended with the
most serious symptoms, and even death ; for if the
fractured extremity punctures the membrane of
the lungs, the air is drawn into the cavity of the
chest, and from thence is pressed into the cellular
substance, and the man is blown up in a prodigious
degree.
The sternum. — The sternum is that long and Situation,
squared bone, which lies on the fore part of the
breast over the heart, and which being joined by
the cartilages of the ribs, completes the cavity of
the chest; it is for completing the thorax, and de¬
fending the heart, for a medium of attachment to
the ribs, and for a fulcrum or point, on which the
clavicles may roll.
We find the sternum consisting in the child of tlic.ch|ld
o t ei<rlit pieces#
eight distinct pieces, which run together in the
, d4
40
OF THE TRUNK.
In middle
age three.
Triangular
portion.
Apex.
Base up¬
wards, hol¬
lowed for
the throat.
Articulates
with the
clavicle.
Socket for
the first rib.
Part of the
second rib
touches this.
Central por¬
tion oblong.
Five pitsfor
the attach¬
ment of
eight ribs.
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 carti¬
lage, 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 tra¬
verse the bone, mark where the intermediate carti¬
lages have once been.
1. The upper piece of the sternum is very large,
roundish, or rather triangular, resembling the form
of the heart on playing-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 triangle, 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 implanted
in the interstice betwixt the first and second bone
of the sternum ; so that one half of the socket
for its cartilage is found in the lower part of
this bone, and the other half in the upper end of
the next.
c2. The second piece of the sternum is of a
squared form, very long and flat, and composing
the chief length of the sternum : 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 ; and as three of the lower cartilages
are run into one, there are but five sockets or
marks. The sockets for receiving the cartilages
of the trunk.
41
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 compares 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 dis¬
tinct articulation of the vertebras with each other.
3. This is, in truth, the whole of the bony ster- The third
num ; and what is reckoned the third piece, is a pre¬
cartilage merely, and continues so down to ex¬
treme old age. This cartilage, which ekes out, cartilago
and lengthens the sternum, and which is pointed cnsiformis-
like a sword, is thence named cartilago mu-
cronata, the pointed cartilage ; or cartilago en-
siformis, or xiphoides, the sword-like cartilage.
One half of the pit for the attachment of the
seventh rib is on this portion. This cartilaginous
point, extending downwards over the belly, gives )
a sure origin and greater power to the muscles
of the abdomen, and that without embarrassing
the motions of the body; but this cartilage, which ^°r™eejimes
is commonly short and single-pointed, is some¬
times 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, Surgical
stand so much exposed, that did we not naturally remarks-
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. The sternum is, like the body of a vertebra,
spongy and covered with a thin cortex of bone,
and sheathed with ligaments; and being exposed,
it is very subject to scrofulous inflammation.
The fracture of the sternum is a most serious
accident; for when there is not death in conse-
4 2
OF THE TRUNK.
quence of the injury of the heart, there is a grating
and rubbing of the broken surfaces : for the lower
extremity of the sternum is carried forward in in¬
spiration ; and therefore, when there is a fracture,
the lower part moves upon the upper part, and if
not restrained, it will cause inflammation and sup¬
puration beneath.
PELVIS.
To give a steady bearing to the trunk, and to
connect it with the lower extremities by a sure and
firm joining, the pelvis is interposed; which is a
circle of large and firm bones, standing as an arch
betwixt the lower extremities and the trunk. Its
arch is wide and strong, so as to give a firm bearing
to the body ; its individual bones are large, so as to
give a deep and sure socket for the implantation of
the thigh bone ; its motions are free and large,
bearing the trunk above and rolling upon the thigh
bones below ; and it is so truly the centre of all the
great motions of the body, that when we 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.
Pelvis con- The pelvis is named from its resembling a basin
the'chiid in its form ; or, perhaps, from its office of containing
of many the urinary bladder, rectum, vagina, and womb : it
SI of consists in the child of many pieces, but in the
four- adult it is formed of three large bones and a smaller
one; viz. the sacrum, and ossa innominata, and os
coccygis.
The sacrum. Os sacrum The names, os sacrum, os basilare,
&c. seem to relate rather to its greater size than to
its ever having been offered in sacrifice. This bone,
vertebra;0 appendix, the os coccygis, is called the false
spine, or the column of the false vertebrae : authors
making this distinction, that the true vertebras are
those of the back, neck, and loins, which possess
OF THE TRUNK.
43
recognise in
the adult
motion, a column which grows gradually smaller
upwards ; the false vertebrae are those of the sacrum
and coccyx, which are conical, with the apex or
point downwards, and the base, viz. the top of the
sacrum, turned upwards to meet the true spine, and
which have no motion like the pieces of the spine.
The bones of which the sacrum is composed had Thesac.um
originally the form of distinct, small vertebrae, distinct^
These distinctions are lost in the adult, or are recol- Pieces or
lected only by the marks of former lines; for the vertebrse-
original vertebrae are now united into one large and
firm bone.
We can recognize the original vertebrae, even in which we
the adult bone ; for we find it regularly perforated
with holes, for the transmission of the spinal nerves: bone,
we find these holes regularly disposed in pairs : we
see a distinct white and rising line, which crosses
the bone, in the interstice of each of the original
vertebrae, and marks the place where the cartilage
once was; and by these lines, being five in num¬
ber, with generally five pair 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 projec¬
tion of the spinous processes.
The os sacrum, thus composed, is among the Substance
lightest bones of the human body, with the most s,pongy'
spongy substance, and the thinnest tables ; 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 Form tri-
triangular shape ; the base of the triangle turned anguIar°
upwards to receive the spine; its inner surface is Concave
smooth, to permit the head of the child in labour Wlthin'
to glide easily along ; and its outer surface is irre- irregular
gular and rough, with the spines of former verte- °"v[hc bacK
brae, giving rise to the great glutaei muscles, (which
form the contour of the hip,) and to the strong
muscles of the back and loins, the longissimus dorsi
44
OF THE TRUNK.
and sacro-lumbalis, which are for raising the spine
and sustaining the body.
Its cavity. It has in it a triangular cavity under the arch of
its spinous processes; which cavity is continued
Triangular, 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,
before it descends to this place, divided into a great
many thread-like nerves, has altogether the form of
a horse's tail, and is therefore named cauda equina.
Foramina. From this triangular cavity the nerves of the cauda
equina go out by four, sometimes five, great holes
on the fore part of the sacrum, holes large enough
to receive the point of the finger : grooves are seen
running from these holes, for the passage of the
sacral nerves. The first three nerves of the sacrum
joining with the last two nerves of the loins, form
the sacrosciatic 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
four holes, whose size is nearly equal to those on its
fore part: these transmit no great vessel nor nerve,
and seem to be merely for diminishing the weight
and substance of the bone.
Basearti- All the edges of the sacrum form articulating
with "the points, by which it is joined to other bones. The
vertebra. 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 join¬
ing of the last true vertebra witli the top of the
sacrum, is a point where there is more motion than
Artiouiat- in the higher parts of the spine. The sacrum has
mg process- two articulating surfaces, which stand perpendicular,
and correspond with those of the lower lumbar
Apex with vertebra. The apex, or point of the sacrum, has the
the os coc- ... a . i • i • • .
cygis. 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 con-
OF THE TRUNK.
4 5
tinuing longer moveable in women is very plain,
since the lower point of the coccyx in women is felt
yielding in the time of labour, so as to enlarge
greatly the lower opening of the pelvis. The sides Lateral ar-
of the os sacrum form a broad, rough, and deeply ^scabrous
indented surface, which receives the like rough surface,
surface of the haunch bones, by that sort of union
which is called synchondrosis : but here the surfaces
are so rough, and the cartilage so thin, that it resem¬
bles more nearly a suture; and by the help of the
strong ligaments, and of the large muscles which
arise in common from either bone, makes a joining
absolutely immoveable, except by such violent force
as is in the end fatal.
Thus the original state of this bone is easily
recognized 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 Oscoccygis
to the beak of a cuckoo, is a small appendage to tothesa-'*
the point of the sacrum, terminating this inverted crum; in
column with an acute point, and found in very cartilage,
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 Moves on
distinct bones, which continue moveable upon each the sacrum'
other till manhood ; then the separate bones gradu¬
ally unite with each other, so as to form one conical
bone, with 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 advanced years, it is at last firmly united, later in in advanc-
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 gradu¬
ally of a roundish form, convex without, and concave
46
OF THE TRUNK.
inwards, forming, with the sacrum, the lowest part
it hasn° of the pelvis behind. It has no distinct holes, but
the last sacral 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.
The prolongation of this appendix to the spine by a
succession of additional bones, forms the tail in quad¬
rupeds ; while, in man, the coccyx is turned in to
support the parts contained in the pelvis, and to
afford an elastic extremity to the spine, on which,
in some measure, we rest in sitting: in women it
continues so moveable as to recede in time of la¬
bour, allowing the child's head to pass. This bone
is apt to be dislocated by our falling with the breech
on a projecting corner, or, more ignominiously, by
kicks in the same place. When dislocated, it gives
rise to very considerable distress, and to disorder of
the function of the rectum and neck of the bladder.
Os innorni- The ossa innominata are the two great irregular
natum. 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 retain their
original names, though united into one great bone :
Divided we continue to explain them as distinct bones, by
into three. ^|ie names Gf os ijiuni} 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 hip, and which forms the rounding 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 incommoding the articulation with the
thigh-bone, gives a firmer hold to the cartilage which
OF THE TRUNK.
47
lines that cavity, and is the point into which a strong
ligament from the head of the thigh-bone is im¬
planted.
The os ilium, or haunch-bone, is named from its os iiii.
forming the flank. It is the largest part of the os
innominatum. It rises upwards from the pelvis in
a broad expanded wing, which forms the lower
part of the cavity of the abdomen, and supports the
chief weight of the impregnated womb (for the
womb commonly inclines to one side). The os ilium
is covered 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, Ala.
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 car- Spine,
tilage 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. The external oblique muscle of the abdomen
is inserted into the outer edge or labrum, and from
this margin the gluteus maximus and medius arise.
The internal oblique arises from the middle rough
line, and the transversalis from the inner edge of
the spine. 2. The two ends of this spine are abrupt, Spinous
and the points formed upon it are consequently pvocesscs'
named spinous processes, of which there are two at
its fore and two at its back end. The two posterior Posterior,
spinous processes are close by each other, and are suP^rii>r:
_ , J t and inferior.
merely 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 ligaments
which bind this joint. Where the spine terminates
48
OF THE TRUNK.
Anterior
superior.
Anterior
inferior.
Dorsum.
Cup.
Articula¬
tion with
the sacrum
Scabrous
surface.
Linea inno
minata.
(
in this process the great muscle of the hip, the
gluteus maximus, takes its rise. 3. The two anterior
spinous processes are more distinct, and more im¬
portant marks; for the anterior superior spinous
process is the abrupt ending of the spine, or circle
of the ilium, with a swelling out: from which jutting
point the sartorious muscle, the longest, 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 tensor vaginse 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 Poupart's
ligament. The lower anterior spinous process is
a small bump, or little swelling, about an inch under
the first one, which gives rise to the rectus femoris
muscle, or straight muscle of the thigh, which lies
along its fore part; and upon the inside of the pro¬
cess there is a depression lodging the iliacus internus
and psoas magnus.
The back, or dorsum of the os ilium, is covered
with the three great glutasi muscles. We remark
in a strong bone a semicircular ridge, which runs
from the upper part of the anterior inferior spinous
process to the lower part of the notch, and which
marks the place of origin of the gluteus minimus.
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 sur¬
face, by which it is connected with the os sacrum
at its side ; the very form of which declares the
nature of this joining, and is sufficient argument
and proof that the joinings of the pelvis do not
move.
The acute line, which is named linea innomi-
nata, is seen upon the internal surface of the bone,
dividing the ala, or wing, from that part which forms
the true pelvis. This line composes part of the
brim of the pelvis, distinguishes the cavity of the
pelvis from the cavity of the abdomen, and marks
the circle into which the head of the child descends
of the trunk.
49
at the commencement of labour. This bone enters j^tabu"
into the composition of the socket for the thigh¬
bone, in a manner to be presently explained.
In many parts of the bone we see holes for trans¬
mitting vessels ; we find one particularly large in
the cup.
The os ischium, or hip-bone, is placed perpen- os ischii.
dicularly 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 sometimes
named acetabulum ischii, as peculiarly belonging 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.
The body is the uppermost and thicker part of body,
the bone which helps in forming the socket; and
among the three bones, this one forms the largest
share of it; nearly one half. From the body, a
sharp-pointed process, named spinous process of the spinous
ischium, is projected backwards; which, pointing p,ocess'
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 ilium with the
sacrum, is completed into a large round hole ; which Notch of
is in like manner named the sacro-sciatic hole, and lhum'
gives passage to the pyramidalis muscles, and to the
great nerve of the lower extremity, named the great
sacro-sciatic nerve.
From the tuber, or round knob, being the point Tubei-
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 of bone.
It is remarkable as being the point towards which
the posterior or lower sacro-sciatic ligament extends,
and as a point which gives rise to several of the
vol. i. e
50
OF THE TRUNK.
strong muscles on the back of the thigh, and espe¬
cially to those which form the hamstrings, semi-
tendinosus, semi-membranosus, and long head of the
biceps cruris.
Between the scabrous surface on the tuber, and
the edge of the acetabulum, there is a smooth surface,
Cervix. rather depressed, which is called the cervix. It is
covered with a cartilage which allows the tendon of
the obturator internus to move easily.
Ramus. The ramus, or branch, rises obliquely upwards
and forwards, 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 forwards and backwards;
so that one edge forms the arch of the pubis, while
the other edge forms the margin of the thyroid hole.
os pubis. 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.
body. 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 shallow¬
est 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 ligament of the
thigh, the pubis is very smooth. On the angle or
Crest. crest there is a process which is frequently called
tuberous angle : from this process there are two
Linea iieo ridges traced ; one goes to meet the line on the
ilium, forming the brim of the pelvis, and forms the
linea ileo pectinea, or linea innominata; the other
goes down towards the edge of the acetabulum:
between these two ridges there is a flat surface
Ramus. giving origin to the pectineus. The ramus, or
of the trunk.
51
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, Groove of
there is a groove, which forms that part of the theospubls'
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 neces¬
sary to repeat, in short definitions, certain points
which are oftener mentioned as marks of other
parts.
The promontory of the sacrum is the projection Promon-
formed by the lowest vertebra of the loins, and the ™
■ SaClllIIt.
upper point of that bone. The hollow of the Hollow,
sacrum is all that smooth inner surface which gives
out the great nerves for the legs and pelvis. The Lesser
lesser angle, in distinction from the greater angle angK"
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 Crest of
the bone over the joining or symphysis pubis. The publs'
posterior symphysis of the pelvis is the joining of symphyses-
the sacrum with the ilium, while the symphysis
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, have been
already sufficiently explained. The acetabulum, Acetabu-
so named from its resemblance to a measure which lum iscllii-
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 pro¬
portion belongs to each bone ; that it is made, two
fifths by the os ilium, twofifths 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. On the lower
part of the margin there is a deficiency of bone ;
52
op the trunk.
which, however, is made up by a ligament, and yet
not so perfectly, but that dislocation of the head of
the femur sometimes takes place in this direction.
Bnm of the 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 the impregnated
womb, keeps it up against the pressure of the labour
pains •, and sometimes this line has been " as sharp
" as a paper-folder, and has cut across the lower
" segment of the womb and so, by separating
the womb from the vagina, has rendered the delivery
impossible •, and the child escaping into the abdomen
Outlet. among the intestines, the woman has died. * The
outlet of the pelvis is the lower circle again, com¬
posed 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 sud¬
denly, and with such violence upon the soft parts,
Thyroid, that the perineum is torn. The thyroid hole is
that remarkable vacancy in the bone which perhaps
lightens the pelvis, or perhaps allows the soft parts
to escape from the pressure, during the passage of
the head of the child.
Peculiar;- The marks of the female skeleton have been
fcmaK '' sought for in the skull, as in the continuation of the
pelvis. sagittal suture; hut 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 open-
ngs, and bones of greater strength, the female
pelvis is very shallow and wide, with a large cavity,
and slender bones, and with every peculiarity which
* This condition of the brim is exhibited in a skeleton distorted
by ricketts, in my collection, now in the possession of the College
of Surgeons of Edinburgh. The woman died in child-bed, and
it was found that the arm of the child had escaped from the
womb, at the place where it was cut by the sharp spine of bone.
of the trunk.
may conduce" to the easy passage of the child. And
this occasions that peculiar form of the body which
the painter is at great pains to mark, and which is
indeed very easily perceived ; for the characteristic
of the manly form is firmness and strength ; the
shoulders broad, the haunches small, the thighs in a
direct line with the body, which gives a firm and
graceful step. The female form again is delicate,
soft, and bending ; the shoulders are narrow ; the
haunches broad ; the thighs round and large ; the
knees, of course, approach each other, and the step
is unsure: the woman 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 explained as a whole. Though per¬
haps its chief office is supporting the spine, still its
relation to labour deserves to be observed; 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 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, of the
that the joinings of the pelvis dissolved in every the joining
labour; that the bones departed, and the openings of the Pei-
were enlarged; that the child passed with greater
ease; and " that this opening of the basin was no
44 less natural than the opening of the womb." By
many accidents, this opinion has been often strength¬
ened and revived ; and if authority could determine
our opinion, we should acknowledge, that the join¬
ings of the pelvis were always dissolved as a wise
e 3
OK THE TRUNK.
provision of nature for facilitating natural, and pie-
venting 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 join¬
ings, but much more from the other offices which
these bones have to perform ; for if the pelvis be, as
I have defined it, an arch standing betwixt the trunk
and the lower extremities on which the body rolls,
its joinings could not part without pain and lameness,
perhaps inability for life.
One chief reason drawn from anatomy is this:
that in women dying after labour, the cartilages
of the pelvis are manifestly 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 cartilage only, as was once supposed, but
a peculiar cartilage covers the end of each bone, and
these are joined by a membraneous 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 corrupted ligament may be called a
separation of the bones ; but it is such a separation
" as equals only the back of a common knife in
of the trunk.
" breadth, and will not allow the bones to depart
from each otherthe joining is still strong,
for it is surrounded by a capsular ligament, 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
44 hands, still, though the bones can be bent back-
" wards and forwards, they cannot be pulled from
" each other the tenth part of an inch." These
enquiries 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 wil¬
lingly abide.
Now, it is plain, that since a separation, amounting
only to the 12th part of an inch, occasions death,
this cannot be a provision 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 want¬
ing of women whose bones were separated during
labour ; but what is there so absurd, that we shall not
find a precedent or parallel 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-con¬
dition for many years, with the pelvis also affected ;
its openings gradually more and more abridged ; the
miserable woman suffering lingering labour, and
undergoing the delivery by hooks, with all the
e 4
OF THE TRUNK.
violence 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 sometimes by internal
disease ; but if it be affirmed that " the joinings 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 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
universally acknowledged ; that the pelvis support¬
ing the trunk is the centre of its largest motions:
that if the bones of the pelvis 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 dis¬
solved 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 attendants
cannot even move her legs without intolerable an¬
guish, as if torn asunder t : there sometimes follows
a collection of matter within the joint (the matter
extending quite down to the tuber ischii), high
fever, delirium, and death t; or, in case of recovery
(which is indeed more frequent), the recovery is
slow and partial only ; a degree of lameness remains,
* I have known the synchondrosis pubis burst by straining.
The man stood over the weight which he strained to lift, and
felt something give way. The case terminated in suppuration
around the joint and caries of the ossa pubis. See my Col¬
lection.
t Denman.
^ Dr. Hunter, Med. Observ. and Enquir. Vol. ii. p. 321.
OF THE TRUNK.
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 very tight; and they must submit
to be confined long : by neglect of which precautions,
sometimes by the rubbing of the bones, a preter¬
natural joint is formed, and they continue lame for
years, or for life * ; or sometimes the bones are
united by ossification ; the callus or new bone pro¬
jects towards the centre of the pelvis, and makes it
impossible for the woman to be again delivered of a
living child.t
Now this history of the disease leads to reasons
independent of anatomy, which prove, that this se¬
paration 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 separation of the bones,
how can we believe that it happens, when we see
women walking during all their labour, and, in place
of being pained, are rather relieved by a variety of
postures, and by walking about their room ? 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 few days more ?
or can we believe, that there is a tendency to separa¬
tion 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 se¬
paration 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 instru-
* Denman says twenty-five or thirty years.
f Spence's cases.
58
bones of the
ments, who yet recover as from a natural delivery,
and who also rise from bed on the third or fourth
day ? I have only to add to this catalogue of evils
attending the separation of the symphysis or sychon-
drosis in the female pubis, that I have known the
bones separated by violence in man, and the accident
was attended with tedious suppuration and hectic.
BONES OF THE THIGH, LEG, AND
FOOT.
The 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, as commonly 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 loaded with still greater burdens than
the mere weight of the body itself.
Femur; go The thigh-bone is one of the most regular of the
cylindrical cylindrical 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
curved. fore part of 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 are authors who have ascribed
it to the nurse carrying the child by the thighs, and
its soft bones bending under the weight. There is
another author, very justly celebrated, who imputes
it to the weight of the body, and the stronger action
of the flexor muscles, affirming, that it is straight in
thigh, leg, and foot.
.59
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 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 would put the thigh¬
bone in their power, to bend it in any degree, and to
cause distortion. But the end of all such specula¬
tions is this, that we find it bended in the foetus, not
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 Head beins
n . f - iii i i • more than
pertect 01 any in the human body, tor its circum- half a circle,
ference 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
deepened by the cartilage which borders it, so that
this is naturally, and without the help of ligaments,
the strongest joint in all the body ; but among other
securities which are superadded, is the round liga¬
ment, the mark of which is easily seen, being a broad
dimple in the centre of its cavity. In the surface of
the head or ball we observe a small pit for the attach- pit.
ment of the round ligament of the hip-joint.
The neck of this bone is the truest in the skeleton ; neck,
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
60
1jones of the
shoulders of the bone, to keep its motions wide and
free, and unembarrassed by the pelvis ; tor without
this great length of the neck, its motions had been
checked even by the edges of its own socket.
trochanter. The trochanters are the longest processes in the
human body for the attachment of muscles, and
they are named trochanter (or processes for turning
the thigh), from their office, which is the receiving
those great muscles which not only bend and extend
the thigh, but turn it upon its axis ; or these pro¬
cesses are oblique, so as to bend and turn the thigh
at once.
Major. 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 ; therefore the great trochanter
stands above the neck, and is easily distinguished
outwardly, being that great bump which we feel so
plainly in laying the hand upon the haunch. On the
upper and fore part 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 inserted, viz. the pyriformis, the
gemini, the obturator internus and externus. On
the lower part there is a very strong marked ridge,
which is for the insertion of the gluteus maximus,
Tr. minor. 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 directed backwards, so that
the muscles inserted into it turn the toe outwards at
the same time that they raise the femur. It is deeper
in the thigh, and never to be felt, not even in luxa¬
tions. Its muscles, also, viz. the flexors of the thigh,
by the obliquity of their insertion 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
THIGH, LEG, AND FOOT.
6 I
into this point. On the neck of the thigh-bone
there is a very conspicuous roughness, which marks
the place of the capsule or ligamentary bag of the
joint; for it encloses the whole length of the neck
of the thigh-bone.
Betwixt the greater and lesser trochanters, there ^rt"r^°"
runs a rough line, the inter-trochantral line, to which line" ™
the capsular ligament is attached, and into which the
quadratus femoris is inserted.
The linea aspera is a rising or prominent line, Linea
very rugged and unequal, which runs all down the a*pera
back part of the thigh: it begins at the roots of the
two trochanters, and the rough lines from each tro¬
chanter meet about four inches down the bone ;
thence the linea aspera runs down the back of the ^°"bl®rid
bone a single line, and forks again into two lines, below,
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 Condyles-
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 tuberosities, which,
by their flat faces, form the joint, swell out above the
joint, and are called the condyles. The inner con- the inner
dyle is larger, to compensate for the oblique position largest-
of the thigh-bone ; for the bones are separated at
their heads by the whole width of the pelvis, but are
drawn towards a point below, so as to touch each other
at the knees. On the fore part of the bone, betwixt
the condyles, there is a broad smooth surface upon
which the rotula, patella, or pulley-like bone glides.
The outer side of this trochlea is the largest and most Trochlea,
prominent. On the back part of the thigh-bone, in Notch,
the middle betwixt the condyles, there is a deep
notch, which gives passage to the great artery, vein,
and nerve, of the leg.
62
bones of the
Nutritious Xhe great nutritious artery enters below the middle
artery. Gf this bone, and smaller arteries enter through its
porous extremities ; as may be known by many small
holes near the head of the bone.
review of Xhe head of the thigh-bone is round, and set
pal points of down deeply in its socket, to give greater security
demonstra- to a joint so important, 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 transverse
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 wraps
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 con¬
dyles 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 assured its neck is
broken, the trochanter being displaced, and the
THIGH, LEG, AND FOOT.
63
broken head remaining in its socket; but when the
trochanter remains in its place, we should conclude
that the joint is but little injured, or that it is only
a bruise of those glands or mucous follicles, which
are lodged within the socket, for lubricating the
joint.
The tibia is named from its resemblance to a Tibia-
pipe ; the upper part of the tibia, representing the °'m
expanded or trumpet-like end, the lower part repre¬
senting 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 ancle. There is no security for the knee-
joint, by the form of its bones, for they have plain
flat heads ; they are broad indeed, but they are
merely laid upon each other. It is only by its liga-
i ments that this joint is strong; and by the number
■ of its ligaments it is a complex and delicate joint,
i peculiarly liable to disease.
The upper head of the tibia is thick and spongy, upperhead.
and we find there two broad and superficial hollows,
as if impressed, while soft, with the marks of the con- Two arti-
dyles of the thigh-bone ; and these slight hollows are surfaces',
all the cavity that it has for receiving the thigh-bone. Ridge.
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 Pits,
back part for the attachment of the crucial ligaments.
The spongy head has also a rough margin, to which Margin,
the capsular ligament is tied. On the fore part of Tubercle,
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 Artieuiat-
margin of the joint, a smooth articulating surface, ^gtsh"r^.
(like a dimple impressed with the finger,) for re- la.
bones of the
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 ligaments, but not received
into any thing like a cavity.
Bodytri- The body or shaft of the bone is of a prismatic or
angular. 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 posi¬
tion to the foot. One line, the anterior angle, a little
waved, and turned directly forwards, is what is
shin. 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
Posterior bone. Another line, less acute than this, is turned
3ngle' directly backwards ; and the third acute line, which
angle"1 completes the triangular form, is turned towards the
fibula, to receive a broad ligament, or interosseous
membrane, which ties the two bones together.
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 anticus, 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 popli-
teus muscle, which is bounded on the lower part by
a ridge giving origin to one of the flexors.
Lower The lower head of the tibia composes the chief
1,ead- part of the ancle-joint. The lower head is smaller
than the upper, in the same proportion that the
Malleolus ancle is smaller than the knee. The pointed part
intern™. ^ head. of the tibia represents the mouth¬
piece, or flat part of the pipe, and constitutes the
bump of the inner ancle. The lower end of the
fibula lies so upon the lower end of the tibia, as to
ofThe1fibu- fo,rm th.e outer ancle ; and there is on the one side
h. of the tibia a deep hollow, like an impression made
6
THIGH, LEG, AND FOOT.
65
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 ancle, passes
beyond the bone of the foot, and by lying upon the
side of the joint, guards the ancle, so that it cannot
be luxated outward, without this pointed process of
the malleolus internus, or inner ancle, being broken.
The lower extremity of the tibia has that sort of Sca.Phoid
excavation to correspond with the astragalus, to cavity"
which anatomists give the name of scaphoid cavity.
On the back of the lower head of the bone there Groove for
is a groove which transmits the tendon of the tibialis p^tic^13
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 trans¬
mission of the nutritious artery to the centre of the
bone. In amputation of the leg, this artery is some¬
times 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 assisted by the fibula in bearing the
weight, the fibula, or slender bone, being merely laid
upon the side of the tibia, for uses which shall be
explained presently. The tibia is thick, with much
cancelli or spongy substance 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 betwixt the
hands when soft: this distortion makes the process
of the inner ancle lie not regularly upon the side of
that joint, but a little obliquely forward, which deter¬
mined the obliquity of the foot, and this 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 ancles ; the
inner ancle advancing a little before the joint, and
the outer ancle receding in the same degree behind it.
VOL. i. F
66
BONES OF THE
Fibuk. The fibula, which is named so from its resem¬
blance to the Roman clasp, is a long slender bone,
which is useful partly in strengthening the leg, but
chiefly in forming the ancle-joint and in affording
attachment to muscles. The tibia only is connected
with 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 ancle.
The fibula is a long and slender bone, the longest
and slenderest 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 til]
the last piece be replaced, or till the fracture be
firmly 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 the sharp line of the
tibia, and the interosseous membrane passes betwixt
Spines. them. The other lines or spines are in the interstices
of the attachment of muscle, of which no fewer than
six take their origin here, making the bone irregular
with spines and grooves. There arise from the fibula,
1. The soleus from the back part of the head ; c2. The
tibialis posticus from the back and lower part of
the bone ; 3. The flexor longus pollicis all down the
back part of the bone ; 4. The peroneus longus from
nearly the whole length of the bone ; 5. The pero¬
neus brevis from the middle and lower part; 6. The
peroneus tertius from the fore part of the bone. The
bone lies in a line with the tibia, on the outer side of
Upper head, 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 the biceps cruris;
smooth, and with , cartilage within ; and is laid upon
a plain smooth surface, on the side of the tibia, a
uSdyto below the knee: and though the fibula is not
the tibia, received deep into the tibia, this want is compen¬
sated for by the strong ligaipents by which this little
thigh, leg, and foot.
67
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 tendi¬
nous expansion of the thigh ; but above all, by the
tendons ot the outer hamstrings being fixed into this
knot of the fibula, and expanding from that over the
fore part of the tibia.
The lower head of the fibula is broad and flat, Lower
and is let pretty deep into a hollow on the side of the head"
tibia ; together they form the socket of the ancle-
joint for receiving the bones of the foot. The extreme Malleolus
point of the thin extremity gives attachment to the txernus<
perpendicular ligament of the joint, and is called the
malleolus externus. On the back part of this lower
head there is a furrow which lodges the tendons of
the peronei muscles. The ancle-joint is one of the ,A.ncle"
purest hinge-joints, and is very secure ; for there is Jomt'
the tibia, at the process of the inner ancle, guarding
the joint within, there is the fibula passing the joint
still further, and making the outer ancle 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 motion ; make the joint
firm and strong, and will not allow of luxations, till
one or both ancles be broken. We know that there
is little motion betwixt the tibia and fibula; none
that is sensible 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 slight and imperceptible, is very constant;
for these joinings 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, and which are so seldom
anchylosed, i. e. joined into one by disease.
The fibula may be thus defined : it is a long General
slender bone, which answers to the double bone of of'tKbu-
the fore-arm, completes the form, and adds some- la.
what to the strength of the leg; it gives a broader
origin for its strong muscles, lies by the side of the
f 2
68
bones 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 connection with the knee, passes
beyond the ancle-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 ancle, it is so true, that the ancle cannot yield
till this guard of the fibula be broken. This fracture
of the lower part of the fibula, attended with more
or less injury of the inner ligament of the ancle-
joint, is by far the most frequent accident received
into a London hospital.
Patella. Patella, rotula, or knee-pan, is a small thick
bone, of an oval, or rather triangular form. The
Basis. basis of this rounded triangle is turned upwards to
receive the four great muscles which extend the leg;
Apex. 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
R'dge. divided by a ridge into two unequal parts : round the
margin of the bone there is a slight depression for
the attachment of the capsular ligament. This liga¬
ment 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 process of the tibia, (as the olecra¬
non 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 olecranon 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 exceptions to the common rules and methods
of setting broken bones.
The patella is manifestly useful, chiefly as a lever;
for it is a pully, which is a species of lever, gliding
upon the fore part of the thigh-bone, upon the
smooth surface which is betwixt the condyles. The
projection of this bone upon the knee removes the
11
thigh, leg, and foot.
69
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 patella sinks down, concealed into a
hollow of the knee. When the muscles begin to act,
the patella begins to rise from this hollow; in pro¬
portion as they contract, they lose of 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 contractile power of the muscles.
What is curious beyond almost any other fact con¬
cerning the fractures of bones, the patella is seldom
broken by a fall or blow; in nine often cases, it is
rather torn, if we may use the expression, by the
force of its own muscles, while it stands upon the
top of the knee, so as to rest upon one single point;
for while the knee is half-bended, and the patella in
this dangerous situation, the leg fixed, and the
muscles contracting 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 the man's body ; and often, by
a sudden violent exertion, their power is so much
increased, that they snap the patella across, as we
would break a stick across the knee.
The tarsus, or instep, is composed of seven large ofthe
bones, which form a firm and elastic arch for sup- tarsus-
porting 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 anchy¬
losis with each other ; but the effect is rather a
diffused elasticity than a marked and perceptible
motion in any one joint.
70
bones of the
The seven bones of which the tarsus is composed
are, 1. The astragalus, which, united with the tibia
and fibula, forms the ancle-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
naviculars, or boat-like bone, which joins three
smaller bones of the fore part of the tarsus to the
astragalus. 4. The os cuboides, which joins the
fore part of the os calcis to the external cuneiform
bone. The 5th, 6th, and 7th, are the smaller bones
making the fore part of the tarsus; they lie imme¬
diately under the place of the shoe-buckle, and are
named the three cuneiform bones, from their
wedge-like shape ; and it is upon these and the
anterior surface of the cuboides that the metatarsal
bones, forming the next division of the foot, are
implanted.
These bones of the tarsus form, along with the
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 ; then there is a transverse arch
formed by the cuboides and the cuneiform bones;
and again, there is another arch within this, formed
among the tarsal bones themselves, one within
another, and laid horizontally, i. e. betwixt the
astragalus, os calcis, cuboides, cuneiform bones, and
naviculare. It is these arches which give so perfect an
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.
Astragalus. (1.) The astragalus is the greatest and most
remarkable bone of the tarsus, and which the sur¬
geon is most concerned in knowing. The semicircu¬
lar head of this bone forms a curious and perfect
General pully. The circle of this pully is large ; its cartilage
description. js smooth and lubricated ; it is received deep betwixt
the tibia and fibula, and rolls under the smooth arti¬
cular surface of the latter, which, being suited to
this pully of the astragalus, with something of a boat¬
like shape, is often named the scaphoid cavity of the
THIGH, LEG, AND FOOT.
71
tibia. 1. We remark in the astragalus its articulating
surface, which is arched, high, smooth, covered with
cartilage, lubricated, and in all respects a complete
joint. Its form is that of a pully, which, of course,
admits of but one direct motion, viz. forwards and
backwards. 2. We observe its sides, which are
plain, smooth, and flat, covered with the same carti¬
lage, forming a part of the joint, and closely locked
in by the inner and outer ancles, 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 fore part, or
rather the fore end, of the astragalus, a large round
head, as regular as the head of the shoulder-bone, by
which it is articulated with the scaphoid bone.
1. Superior surface corresponding with the sea- ?*ointSLof
r . n -w- i • i • demonstra-
phoid cavity of the tibia. 2. Internal articulating tion.
surface for the malleolus internus. 3. External ^^j1'
articulating surface for the extremity of the fibula, articulating
4. Inferior and posterior articulating surface joining
with the body of the os calcis. 5. Inferior and ante- surface,
rior surface articulating also with a corresponding Infenor
o it c} poster'or.
surface of the os calcis. 6. The ball or anterior arti- inferior
culating surface which enters into the socket of the ^fjnor'
naviculare. 7* A smooth part, which is like a con- smooth
tinuation of this last, but which rests upon a cord of surface-
ligament, which is stretched betwixt the os calcis
and naviculare. 8. Deep fossa, dividing these two Fossa,
inferior articulating surfaces, for the lodgment of
a ligament which unites this bone to the os calcis.
9. Furrow for attachment of the capsular ligament.
On the inside of the bone we see a hollow and a Attachment
rough protuberance for the attachment of the deltoid toid^t-'
ligament, which comes down from the tibia; a ment.
point of the anatomy of the first consequence to the
surgeon.
(2.) The os calcis is the large irregular bone of os calcis.
the heel; it is the tip or end of the arch formed by
the tarsal and metatarsal bones. There is an irre- Great
gular surface on the highest part of the projection procos5'
f 4
72
BONES OF THE
First.
Second.
Third arti¬
culating
surface.
Arch.
Groove.
Fossa-
Tubercle.
Naviculare
Concave
surface.
Convex
surface*
Tubercle^
Cuneiform
bones.
backwards, to which the tendo Achillis 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 articular 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 or excavation, on the
inside, under which the vessels and nerves, and the
tendons also,, pass on safely into the sole of the foot.
On the outer surface of this bone we may observe a
groove, which transmits the tendon of 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 inner part, is
the sinuosity.
We further notice the tubercle which stands inter¬
nally, and gives attachment to the ligamentum inter
os calcis et naviculare, which forms an elastic support
to the lower part of the ball of the astragalus.
(3.) The next bone is named os naviculare, or
os scaphoides, from a fanciful resemblance to a boat.
But this is a name to which anatomists have been
very partial, and which they have used with very
little discretion or reserve : the student will hardly
find any such resemblance. That concave side which
looks backwards is pretty deep, and receives the
head of the astragalus : that flat side which looks
forward 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 gristly ligament, already described,
running betwixt this and the os calcis.
(4, 5, 6.) The cuneiform bones are so named, be¬
cause they resemble wedges,, being laid close to each
thigh, leg, and foot.
7 3
other like the stones of an arch. The most simple and
proper arrangement is 1, 2, and 3 ; counting from
the side of the great toe towards the middle of the
foot; but they are commonly named thus : the first £sj=unei-
cuneiform bone, on which the great toe stands, has n°ume "ag
its cutting edge turned upwards ; it is much larger
than the others, and so is called os cuneiforme
magnum. The second cuneiform bone, or that minimum,
which stands in the middle of the three cuneiform
bones, is much smaller, and is therefore named os
cuneiforme minimum. The third in order, of the Medium,
cuneiform bones, is named os cuneiforme medium.*
These cuneiform bones receive the great toe and
the two next to it. The fourth and fifth toes are
implanted upon the os cuboides.
(7») Os cuboides. — The os cuboides is named from cuboides.
its cubical figure, and is next to the astragalus in
size, and greater than the os naviculare. The three surface for
cuneiform bones are laid regularly by the side of cuneiform
each other ; and this os cuboides is again laid on bone,
the outer side of the third cuneiform bone, and joins articulated
it to the os calcis. Its anterior point is divided into ^th os cal"
two surfaces, for two metatarsal bones : in the lower
surface of the bone is a groove for transmitting the Groove,
tendon of the long peroneus muscle. 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 Place ami
arch, which gives at once a degree of elasticity and use-
of strength which no human contrivance could have
equalled.
Metatarsus. — The metatarsus, so named from its
being placed upon the tarsus, consists of five bones ;
they extend betwixt the tarsus and the proper bones
of the toes.
* The confusion in these names arises from sometimes count¬
ing 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 cuneiforme medium ; for the os cuneiforme 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
stands in the middle betwixt the other two.
74 BONES OF THE
Distinc- 'j'he metatarsal bone of the great toe is the shortest,
and is otherwise distinguished by its strength and the
great size of its extremities. The metatarsal ot the
second toe is the longest, its nearer head being
wedged betwixt the cuneiforme magnum and mini¬
mum, while it has a surface of contact with the medium
and the head of the extremity of the metatarsal bone
of the third toe. The metatarsal bone of the little
toe is also peculiar in the size of its nearer head, and
the manner in which that head projects upon the
outside of the foot to receive the tendons of the
General peroneus secundus and tertius. The metatarsal
bones generally have these peculiarities. 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
square heads, that they may be implanted with great
security ; they grow smaller forwards, 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 in them, 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.
Bail. The further extremities of these bones terminate
in round balls, which correspond with the sockets
Groove. in the first bones of the toes, and a distinct groove
runs round the upper part of the extremity of the
Condyles, bone for the attachment of the capsule. Processes
stand out laterally from the anterior extremities,
which give attachment to the lateral ligaments of
the joint. These bones, by the connection of their
nearer extremities, form an arch corresponding with
the lateral arch of the tarsus : owing to this the
metatarsal of the great toe is placed on a lower
level, so that its great extremity projects into the
sole of the foot, and into it are inserted part of the
thigh, leg, and foot.
7 5
tendon of the tibialis posticus, and the peroneus
longus, whilst the tibialis anticus is inserted into its
upper surface.
The 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 marking the places of the
joints, and the form of the extremities of the bones.
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 great toe has but two phalanges; the other
toes have three ranks of bones: these bones 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 articulating surfaces
of the nearer extremities of the first bones are deep
sockets for the extremities of the metatarsal bones,
and the motions are free. But the articulations of
the second and third joints are proper hinge joints,
the further extremities of the first and second bones
being a flattened trochlea. It is particularly to be Their ex-
noticed, that the heads of these bones are large, jremities
and that they send out a lateral projection for the se
attachment of the lateral ligament. The considera¬
tion of the size and form of the extremities of these
bones, and the nature and attachment of their liga-
' ments, is of the first importance, as explaining the
peculiarity in the dislocation of these bones, and the
manner of reduction.
The sesamoid bones are more regularly found
about the toes than any where else. They are small
bones, like flattened peas, found in tendons, at the
points where they suffer much friction ; or rather
they are like the seeds of the sesamum, whence their
name. They are found at the roots of the great
toe, and of the thumb. We find two small sesamoid
bones, one on each side of the ball of the great
76
bones of the
toe ; and grooves may be observed on the lower
part of the articulating surface of that bone, for
their lodgment and play : they are within the sub¬
stance of the tendons; perhaps, like the patella,
they remove the acting force from the centre of
motion, and so, by acting like pullies, 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 peronei tendons, which run under the sole of
the foot.
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, and not
only is not immediately joined to the trunk by liga¬
ments, nor any other form of connection, but is
parted from it by several layers of muscular flesh, so
that it lies flat, and glides upon the trunk.
scapula. The scapula is a thin bone, which has originally,
description ^ke the skull, two tables, and an intermediate diploe;
but it grows gradually thinner, its tables are more
and more condensed, till in old age it has become in
some parts 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 ter¬
minates, is a broad and flat process, a sure guard
shoulder, arm, and hand.
77
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.
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 luxations are explained
best by studying the skeleton, and being able to
recognize on the living body all the processes and
projecting points.
The flat SIDE of the Scapula is smooth, some- Surfaces,
what concave, and suited to the convexity of the
ribs : it is sometimes called venter. The scapula Venter or
is connected with no bone of the trunk, tied by no f°^fr sur"
ligaments, is merely laid upon the chest, with a
large mass of muscular flesh under it, upon which it
glides, being limited only by the clavicle: 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 subscapularis 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
several divisions of this muscle, but which were
mistaken even by the great Yesalius for the impres¬
sions of the ribs.
The upper or exterior flat surface is slightly con- Exterior
vex ; it is traversed by the spine, which is a very ^um°r
acute and high ridge of bone; it is called the dor¬
sum scapulae. Now the spine thus traversing the
bone from behind forwards, divides its upper surface Divided
into two unequal parts, of which the part above the ^torafosasn3d
spine is smaller, and that below the spine is larger, infrasp*.
Each of these spaces has its name, one supra spina- nata*
tus, 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
bones of the
other musculus infra spinatus scapula?, as being
below the spine. A third muscle is named sub-
scapularis, 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 humerus in
various directions, and which impress the scapula
with gentle risings and hollows on its upper as well
as on its lower surface.
Scapula The triangular form of the scapula must be
triangular. nexj. 0bserveci. Xhe upper line of the triangle is the
superior shortest; it is named the superior costa or border :
costs,.
here the omo-hyoideus has its origin. On this supe-
Notch. rior edge is seen the notch, through which a nerve
and sometimes an artery passes. The lower edge,
costa!°r 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 tarns upon its axis, which is indeed its
ordinary movement. But it gives rise to two smaller
muscles, which, from being a little rounded, are
named the musculi teretes ; they leave their impres¬
sions on this lower costa.
The long side of the scapula, which bounds its
Basis. triangular form backwards, is named the basis of the
scapula, as it represents the base of the triangle.
This line is also like the two borders, a little thicker
or swelled out; and this edge receives 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 back¬
wards ; and sometimes fixing it in its place ; accord¬
ing to the various sets of fibres which are put into
action. These are the larger and lesser rhomboid
muscles, and the great serrated muscle of the fore
part of the chest, which runs under the scapula to be
inserted into the inner edge of the base of the bone.
Superior. The angles of the scapula are two, the superior
inferior. more obtuse, and the inferior more acute. From the
inferior angle the teres major takes its origin, and
shoulder, arm, and hand.
the outer surface of the bone is made smooth by
the passage of the latissimus dorsi muscle. To the
superior angle the levator scapulae is inserted.
The glenoid or articulating cavity of the GIe.noid
scapula is on the point or apex of this triangle. cauty
The scapula is more strictly triangular in a child,
for it terminates almost in a point or apex ; and this
articulating surface is a separate ossification, and is
joined to it in the adult. The scapula towards this
point terminates in a flat surface, not more than an
inch in diameter, very little hollowed, and scarcely
receiving the head of the shoulder-bone, which is
rather laid upon it than sunk into it: it is indeed
deepened a little by a circular gristle, which tips the
edges or lips of this articulating surface, but so little,
that it is still very shallow and plain, and luxations
of the shoulder are infinitely more frequent than of
any other bone.
This head, or glenoid cavity of the scapula, is Neck*
planted upon a narrower part, which tends towards
a point, but is finished by this flat head ; this nar¬
rower 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
capsular ligament, or rather the capsule arises from the
bordering gristle, which 1 have said tips this circle.
The spine of the scapula is that high ridge of spine-
bone which runs the whole length of its upper sur¬
face, and divides it into two spaces for the origin of
the supra and infra spinatus muscles. It is high and
very sharp, standing up at one place to the height of
two inches. It is flattened upon the top, and'with
edges, which, turning a little towards either side,
give rise to two strong fasciae, i. e. tendinous mem¬
branes, which go from the spine, the one upwards to
the upper border of the scapula, the other down¬
wards to the lower border: so that by these strong
* I have met with the accident in practice, and have prepa¬
rations of the fractured bone, so that there can be no doubt of
this accident sometimes occurring, yet it is very rare.
80
BONES OF THE
Triangular membranes the scapula is formed into two triangular
space' cavities, and the supra and infra spinatus muscles
rise not only from the back of the scapula, and from
the sides of its spine, but also from the inner surface
of this tense membrane. The spine traverses the
whole dorsum, or back of the scapula ; it receives
the trapezius muscle, that beautiful triangular muscle
which covers the neck like a tippet, into its upper
edge; whilst from its lower edge a part of the
deltoid muscle departs. This 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 pro¬
montory which forms the tip of the shoulder, and
overhangs and defends the joint.
Terminates This high point is named the acromion process.
acromion. It is the continuation and ending of the spine, which
at first rises perpendicularly from the bone, but, by
a sort of turn or distortion, it lays its flat side
towards the head of the shoulder-bone, and is
articulated with the clavicle: here it is hollow, to
transmit the supra and infra spinati muscles. At
this place, it is thickened, flat, and strong, overhangs
and defends the joint, and is not merely a defence,
but almost makes a part of the joint itself; for,
without this process, the shoulder-bone could not
remain a moment in its socket; every slight accident
would displace it. The acromion prevents luxation
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 shoul¬
der 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.
Coracoid But there is still another security for the joint;
process. for j-here 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
SHOULDER, ARM, AND HAND.
81
directly forwards, and is very conspicuous; and
which, turning forwards with a crooked and sharp
point, somewhat like the beak of a crow, is thence
named the coracoid process. This also guards and
strengthens the joint; though it cannot prevent lux¬
ations, it makes them less frequent, and most pro¬
bably when the arm is luxated inwards, it is by start¬
ing over the point of this defending process. This Three sur-
process has three surfaces for the attachment of faces on lU
muscles, and these muscles are, the pectoralis minor,
the coraco-brachialis, and the short head of the
biceps.
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, belongs to the scapula, which,
sliding easily upon the ribs, yields, and so eludes the
force. Falls upon the shoulder do not dislocate the
shoulder; that accident almost always happens to us
in putting out the hand to save ourselves from falls :
it is luxated by a twisting of the arm, not by the
force of a direct blow. This bone is subject to be
fractured; and then the muscles pull asunder the
fractured portions. The acromion is very apt to be
broken off by falls on the shoulder, and if the acci¬
dent be not treated with due attention to the action
of the deltoid muscle, permanent lameness is the
consequence.
THE CLAVICLE.
The clavicle, or collar-bone, named clavicle from Clavicle,
its resemblance to an old-fashioned key, is to the
scapula a kind of hinge or axis on which it moves
and rolls; so that the free motion of the shoulder is
made still freer by the manner of its connection with
the breast.
VOL. I. Gr
82
BONES OF THE
The clavicle is placed at the root of the neck, and
at the upper part of the breast: it extends across
from the tip of the shoulder to the upper part ot the
Curve. sternum ; it is a round bone, a little flattened towards
the end which joins the scapula ; it is curved like an
Italic J] having one curve turned out towards the
breast; it is useful as an arch supporting the shoul¬
ders, 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.
Pars aero- It is described by authors in three divisions or
Mte amT Pafts) viz. the scapular, sternal extremities, and
media. middle portion. The end next the sternum is round
headround anc* ^at' or button-like; the articulating surface is
roun . ^r[angU]ar^ an(j js receiVed into a suitable hollow on
the upper piece of the sternum. It is not only, like
other joints, surrounded by a capsule or purse ; it is
further provided with a small moveable cartilage,
which (like a friction-wheel in machinery) saves the
parts, and facilitates the motion, and moves conti¬
nually as the clavicle rolls. From this inner head
there stands out an angle, which, when the clavicles
are in their places, gives attachment to the intercla¬
vicular ligament; it ties them to the sternum and to
Groove. each other. The lower surface has a groove in it for
• the subclavius muscle ; the upper surface is marked
by the attachment of the clavicular portion of the
mastoid muscle, and the insertion of trapezius.
Scapular But the outer end of the clavicle is flattened as it
head flat, approaches 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 corresponding 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 liga¬
ment ; but the motion here is very slight and quite
insensible : they are tied firmly by strong ligaments;
and we may consider this as almost a fixed point, for
shoulder, arm, and hand.
83
there is little motion of' the scapula upon the clavicle ;
but there is much motion of the clavicle upon the
breast-bone, for the clavicle serves as a shaft or axis,
firmly tied to the scapula, upon which the scapula
moves and turns, being connected with the trunk
only by this single point, viz. the articulation of the
clavicle with the breast-bone.
The use of the clavicle being to keep the shoulders
apart, it is very obvious that fracture of this bone
must be the consequence of falling, as from horse¬
back, so as to pitch upon the prominence of the
shoulder. It is a very common accident, and requires
considerable care and management in setting the
bone.
humerus.
The os humeri is one of the truest of the cylin- humerus,
drical 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 regular
and round towards the upper end, dilating into a
large round head, where the roundness forms a very
free and moveable joint, turning easily in all direc¬
tions.
The head of this bone is very large: it is a neat h«»d.
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 the glenoid cavity of the
scapula, makes it a very weak joint, easily displaced,
and nothing equal to the hip-joint for security and
strength.
The neck of this bone cannot fairly be reckoned Neck,
such; for, as I have explained in speaking of the
neck of the thigh-bone, this neck of the humerus,
and the necks of most bones (the thigh-bone still
excepted), are merely a rough line close upon the
head of the bone, without any straitening or inter¬
mediate narrowness, which we can properly call a
neck. The roughness round the head of the shoulder- ^"euf"rthe
g 2
84
bones of the
bone is the line into which the capsular ligament is
implanted.
greater tuberosities of the os humeri are two small
tuberosity. bumpg Qf 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 trochanter of the
thigh-bones, they serve similar uses, viz. receiving
the great muscles which move the limb. The
greater 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 same protuberance,
lesser but a little lower. The lesser tuberosity has a
tuberosity. single muscle fixed into it, the subscapularis muscle.
Groove. 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 pully, this
groove is covered in the fresh bones with a thin car-
Ridges. tilage, smooth, and like the cartilages of joints. On
the outside of this groove there is a long ridge for
the insertion of the pectoralis, on the inside one for
insertion of the latissimus dorsi. On the body of the bone,
the deltoid. ak0U£ one third part of its length from the head,
there is an irregularity for the attachment of the
deltoid muscle; and on the inside of the bone near
Foramen, 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
Ridges in bone is somewhat twisted.
ternal and
At the lower end of the bone there are two
external, ridges, one leading to either condyle, which it is of
4
shoulder,. arm, and hand.
85
some consequence to observe; for the articulation
of the humerus and ulna is a mere hinge, the most
strictly so of any joint in the body : it has, of course,
but two motions, viz. flexion and extension: and
there are two muscles, chiefly one for extending, the
other for bending the arm: the flexor muscle lies on
the fore part, 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 flat¬
tened betwixt them; and that the division might
extend beyond the mere edges of the bone, there
are two fascise or tendinous webs, which go off from
either edge of the humerus, and which continue to
divide the fore from the back muscles, giving these
muscles a broader origin ; they are named, from their
office, intermuscular membranes; and this is the
meaning of the two ridges which lead to the two
condyles.
The two projections in which these edges end, are Condyles,
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 con¬
nection with the joint. The chief use of the con¬
dyles 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
extensor muscles, where less strength is required.
But the inner tubercle is much longer, to give origin The inner
to the flexor muscles with which we grasp, which ^est'and
require a bolder and more prominent process to
arise from ; for greater power is needed to perform
such strong actions as grasping, bending, pulling,
while the muscles which extend the fingers need no
more power than just to antagonise or oppose the
g 3
S6
BONES OF THE
flexors; their only business being to untold or open
the hand, when we are to renew the grasp.
It is further curious to observe, that the inner
tubercle is also lower than the other, so that the
articulating surface for the elbow-joint is oblique,
which makes the hand fall naturally towards the face
and breast, so that by being folded merely without
any turning of the os humeri, the hands are laid
across.
Trochlea. The articulating surface which stands betwixt
these condyles, forms a more strict and limited hinge
than can be easily conceived, before we explain the
other parts of the joint. The joint consists of two
surfaces; first, a smooth surface, upon which the
the°head f u^na moves as 011 a hinge > and secondly, of a small
the radium knob upon the outside of the trochlea, 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 one the small
head, and the other the cartilaginous pully, or
trochlea, of the humerus.
Belonging to the joint, and within its capsular
ligament, there are two deep hollows, which receive
Fossa for certain processes of the bones of the fore-arm. One
the coro- deep hollow on the fore part of the humerus, and
noid pro- 1 , . •i« ii • 11
cess. just above its articulating pully, receives the horn¬
like or coronoid process of the ulna, viz. fossa coro-
Fossa for noidea; the other receives the olecranon, or that
nonolecrj 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,
SHOULDER, ARM, AND HAND.
87
again, belongs more strictly to the elbow-joint, for
by it we perform all the actions of bending or ex¬
tending the arm.
The ulna is in general of a triangular or prismatic uina.
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
motion, and almost keeps its place in the dry skele¬
ton, without the help of ligaments or muscles; it
presents, in profile, somewhat of the shape of the
letter g of the Greek, and therefore is named the
sigmoid cavity of the ulna. But this sigmoid sigmoid
cavity were a very imperfect hinge without the two cavity*
processes by which it is guarded before and behind ;
the chief of these is the olecranon, or large bump, olecranon,
which forms the extreme point upon which we rest
the elbow. It is a big and strong process, which,
fitting into a deep hollow on the back of the humerus,
serves two curious purposes; it serves as a long
lever for the muscles which extend or make straight
the fore-arm ; and when by the arm being extended,
it checks into its place, it takes so firm a hold upon
the hinge or joint of the os humeri, as to secure 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 coronoid process, coroncid
from its horn or pointed form : it stands up perpendi- process,
cularly from the upper or fore part of the bone; it
forms the fore part of the sigmoid cavity, and com¬
pletes the hinge. On the root of the coronoid process Tubercle,
there is a rough tubercle for the attachment of the
brachialis internus. The coronoid process is useful,
like the olecranon, in giving a fair hold and larger
lever to the muscles, and to secure the joint; for the
arm being extended, as in pulling, the olecranon
checks into its place, and prevents luxation forwards :
and the arm again being bent, as in striking, push¬
ing, or saving ourselves from falls, the coronoid
g 4
88
bones of the
Greater
sigmoid.
Lesser
sigmoid
cavities.
Pit.
Form pris¬
matic.
Ligament.
Triangular
surface.
Lower
head.
Styloid
process.
process prevents luxation backwards ; so the joint
consists of the olecranon 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 pro¬
cess, it makes a small hollow there in which it rolls;
and this second hollow, touching the edge of the
sigmoid cavity, forms a double sigmoid 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 receiving the glandular apparatus of the joint.
The form of the bone being prismatic, or triangular,
it has, like the tibia, three ridges, one of which is
turned towards a corresponding ridge in the radius,
and betwixt them the interosseous ligament is
stretched; and this interosseous ligament fills all the
arch or open space betwixt the radius and ulna, and
saves the necessity of much bone; gives as firm an
origin to the muscles as bone could have done, and
binds the bones of the fore-arm together so strongly,
that though the ulna belongs entirely to the elbow-
joint, and the radius as entirely to the wrist, they
have seldom 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
anconeus muscle. The ulna, bigger at the elbow,
grows gradually smaller downwards, till it terminates
almost in a point. It ends below in a small round
head, 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
SHOULDER, ARM, AND HAND.
89
the styloid process and the olecranon, the two ex¬
tremities 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, Radius,
and has its position exactly reversed with that of the Positlon*
ulna : for the ulna, belonging to the elbow, has its
greater end upwards ; the radius, belonging to the
wrist, has its greater end downwards; and while
the ulna only bends the arm, the radius carries the
wrist with a rotatory motion, and so 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 e
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, without
approaching it, or compressing the other parts. The
radius lies along the outer 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 upper head
round, flattish, and button-like shape, and lies so smaller-
upon the lower end of the humerus, and upon the
coronoid process of the ulna, that it is articulated
with both bones ; for, 1st, The hollow of its head is hoiw.
directly opposed to the outer condyle 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 below the round flat head is a nar- Neck,
rowness or straitening, called the neck of the
radius; round this neck there is a collar or circular
90
BONES OF THE
Tubercle.
Roughness.
Spine.
Lower
head.
Scaphoid
cavity.
Styloid
process.
ligament, (named the coronary 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, 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, there is a prominent bump, like a
flat button, soldered upon the side of the bone,
which is the point into which the biceps flexor
cubiti, the most powerful flexor muscle of the fore¬
arm, is inserted. On the outside of the bone, and
near the middle, there is a roughness for the inser¬
tion of the pronator teres. Where the face of the
radius is towards the ulna, there is a long sharp
spine for the attachment of the interosseous liga¬
ment.
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, the scaphoides and lunare, 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 there is another small ca¬
vity, 011 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. 1 he little head ol the ulna does not descend
so low as to have any share in forming the wrist.
SHOULDER, ARM, AND HAND.
91
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 outside of the extremity of the radius, we find a
ridge, in the grooves on the sides of this ridge the Ridge and
extensor tendons run. The extensors of the thumb grooves-
also make impressions. On the inside of the head
of the bone, there is a flattened surface for the lodg¬
ment of the pronator quadratus muscle ; and a sharp
line for its insertion.
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 fingers, consisting
each of three joints. 1. The carpus, or wrist, is Carpus,
a congeries of eight small bones, grouped together
into a very narrow space, very firmly tied together
by cross ligaments, making a sort of ball or nucleus,
a solid foundation, or centre, for the rest of the hand.
2. The metacarpus is formed of five long bones, Metacar-
founded upon the carpal bones, and which, depart- pus-
ing 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 free play. 3. The Fingers,
fingers, consisting each of three very moveable joints,
are set free upon the metacarpus, so as to show a
curious gradation of motion in all these parts ; for
the carpal bones are grouped together into a small
nucleus, firm, almost immoveable, and like the nave
of a wheel; then the metacarpal bones founded upon
this are placed like the spokes of the wheel, and
having a freer motion ; and, lastly, the fingers, by
the advantage of this radiated form in the bones upon
which they are placed, move very nimbly, and have
a rotatory as well as a hinge-like motion : so that the
92
BONES OF THE
motion is graduated and proportioned in each divi¬
sion 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.
carpus. 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 pave¬
ment, or like the stones of an arch, with their broader
F°rm. encjs turned outwards. On the internal surface,
again, we find the number of bones not so easily
counted ; for their smaller ends are turned towards
the palm of the hand, which being a concave sur¬
face, the narrow ends of the wedges are seen hud¬
dled together in a less regular form, crowded, and
lapped over each other ; but in this hollow, the four
corner bones are more remarkable, 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 smooth 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 description
of each of them seems more like a riddle, than like
a serious lesson : it cannot be understood, and in¬
deed it need hardly be remembered ; for all that is
useful, is but to remember the connection and place,
and the particular uses of each bone : in reading
of which, the student should continually return to
the plates, or he must have the bones always in
his hand.
SHOULDER, ARM, AND HAND.
93
1. row forming the wrist : viz.
os scaphoides, lunare, cuneiforme,
pisiforme.
Os scaphoides.—The boat-like bone. This name osscaphoi-
of boat-like bone, or boat-like cavity, has been always des*
a favourite name, though a very unmeaning one.
The scaphoid bone is worthy of notice, not merely
from its being the largest bone, but also as it forms
a chief part of the joint of the wrist; for it is this Received
bone which is received into the scaphoid cavity of
the radius : it is a very irregular bone, in which we cavity of
need remember only these points, — the large round theradlus-
surface covered with cartilage, smooth, and answer¬
ing to the cavity in the head of the radius ; the The pr°-
hook-like or projecting process, which forms one of cess'
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 Concavity,
bone takes its name, and by which it is articulated
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 Osiunare.
being somewhat 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 are joined together, to be
articulated with the radius. This bone takes an
equal share in the joint with the scaphoid bone;
and, together, they form a great ball, fitting the
socket of the radius, and of a long form: so that
the wrist is a proper hinge. The chief marks of
this bone are, its greater size, its lunated edge, and
its round head forming the ball of the wrist-joint.
These are its surfaces :
1. The surface of a semilunar shape, and, on the Surfaces,
radial side, attached to the last bone. 2. The con¬
vex surface for articulation with the radius. 3. The
ulnar surface for articulation with the os cuneiforme.
94
bones of the
4. The hollow surface for articulation with the os
magnum, the central bone of the second row.
os cunei- ^phe 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.
Surfaces. l. We may readily distinguish the surface arti¬
culated with the os lunare. 2. Opposite to this the
surface of attachment of the os pisiforme. 3. The
further surface, that is, the side most remote from
the fore-arm, is articulated with the unciforme; a
loose cartilage is interposed betwixt this bone and
the end of the ulna.
Os pisi- The os pisiforme is a small, neat, and round
forme. bone, named sometimes orbicular, or round bone,
but oftener pisiform, from its resemblance to a pea.
^surface Jt is placed upon the cuneiform bone, and it stands
tio^1C"a 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 implanted; the flexor carpi ulnaris, one of the
strong muscles for bending the wrist, is inserted
into it.
2. ROW SUPPORTING THE METACARPAL BONES : viz.
OS TRAPEZIUM, TRAPEZOIDES, MAGNUM, ET
UNCIFORME.
Trapezium. The second row begins with the trapezium, a
pretty large bone, which, from its name, we should
6
SHOULDER, ARM, AND HAND.
05
expect to find of a regular squared form ; while it
has, in fact, the most irregular form of all, especially irregular,
when detached from the other bones. The chief Surfaces of
parts to be remarked in the bone, are the great artIculatIun
socket, or rather the trochlea for the thumb ; and as
the thumb stands off from one side of the hand, this
socket is rather 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 semi¬
lunar surface which touches the convexity of the
scaphoides, and another which articulates with the
trapezoides. The fourth articulating surface of this
bone is opposed to the head of the metacarpal bone
of the finger.
The trapezoides is next to the trapezium, is trapezoi-
somewhat like the trapezium, from which it has its des"
name. It also resembles 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 sea- Five planes
phoides; on its further surface, by two planes, to fngiurfacel"
the metacarpal bone of the fore finger ; on the radial
surface, to the trapezium ; and on the ulnar surface, to
the os magnum ; having thus five planes or surfaces.
The os magnum is named from its great size; not os mag.
that it is the largest of all, nor even the largest bone num>
of the second row, for the unciform 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 sca¬
phoides : on the radial surface the magnum is arti¬
culated with the trapezoides ; on the ulnar surface
with the unciform; 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 fiat hook-like process, which projects to-
96
BONES OF THE
wards the palm of the hand. This is one of the
corner bones; and standing in the end of the row,
it is wedged betwixt the os magnum of its own row,
and the os lunare and cuneiforme of the first row,
its situation js large and squared ; but the thing chiefly re-
aoditspro- marka]3ie js process from which it takes its
name ; a long and flat process of firm bone, unci¬
form, 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 meta¬
carpal bones of the ring and middle fingers.
Their con- All these bones of the carpus, where they are
nections. j0ine(j_ 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
although one only is called cuneiform, they are all
somewhat of the wedge-like form, with their broader
ends outwards, and their smaller ends turned to¬
wards 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 luxation among these bones, and is
extremely rare. *
carplimeta METACARPUS The metacarpus is composed
bones. of four bones, upon which the fingers are founded.
* Late years have presented to me a subluxation of the centre
bones of the first row, which generally ends in considerable obli¬
quity of the hand, or distortion of the wrist. The boy that played
the dragon in the pantomime at Covent-Garden, fell upon his
hands, owing to the breaking of the wire that suspended him in
his flight, and he suffered this accident in both his wrists. These
bones, and their ligaments, are subject to scrofulous inflamma¬
tion.
SHOULDER, ARM, AND HAND.
97
i hey 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 swell out at
their upper ends into big round heads, which keep
the bones much apart from each other. Nothing of
importance 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 Their near-
flat and squared, gives them a firm implantation
upon their centre or nucleus, the carpus; and they
have scarcely any freer motion upon the carpal
bones, than the carpal bones have upon each other.
c2. Their further heads are broader, whereby the Their fur-
articulating parts of the bone are kept apart, which Joundami
gives freedom to the lateral motions of the bones of free,
the fingers. 3. Each metacarpal bone is slightly Thcydi-
bent; 4. and being smaller in the middle, there is ^'ftesome"
a space left betwixt the bones for the lodgment of
the interossei muscles, and they have ridges which Ridges,
mark the place of attachment of the interossei
muscles. 5. These bones taken collectively still They are
preserve the arched form of the carpal bones, being, arc,led-
with the carpal bones, convex outwardly, and con¬
cave 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 arti¬
culating heads of the further extremities of these
bones are flattened, or somewhat grooved, for the
play of the tendons of the interossei muscles; and condyles,
small processes stand out laterally for the attach¬
ment of ligaments, like little condyles. It is farther
necessary to observe, into how small a space the
carpal bones are compressed, how great a share of
the hand the metacarpal bones form, and how far
down they go into the hollow of the hand; for 1
have seen a surgeon, who, not having the smallest
suspicion that their lower ends were so near the
VOL. i. u
bones of the fingers.
wrist as they really are, has, in place of cutting the
bone neatly 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 metacarpal 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, and no metacarpal bone.
Thumb.—The first bone of the thumb resembles
the metacarpal bones in size and strength, but it
differs widely in being set upon the carpus, with a
large and round head ; it 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 pollere ; and the peculiar shape of the
articulating extremities, and the lateral processes or
condyles are, as it were, better characterized than
in the bones of the fingers.
The fingers have each of them three bones:—
These bones are gently arched, uniform, and con¬
vex upon their outer surface, grooved within for the
lodgment of the stronger flexor tendons. 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 more limited
in their motions ; and are strictly hinge joints.
3. Here, as in other hinge joints, there are strong
lateral ligaments, and lateral processes or condyles,
for their attachment. When these lateral ligaments
are burst or cut, the finger turns in any direction;
so that the motions of the fingers are limited rather
by their lateral ligaments, than by any thing peculiar
of the skull in general.
99
in the forms of the bones. 4. The face of each
finger-bone is grooved, so that the tendons, passing
in the palm of the hand, run upwards along this
groove or flatness of the fingers ; and from either
edge of this flatness there rises a ligament of a
bridge-like form, which covers the tendons like a
sheath, and converts the groove into a complete
canal. 5. The last joint or phalanx of each finger is
flattened, rough, and drawn smaller gradually to¬
wards the point of the finger ; and it is to this rough¬
ness that the skin and nail adhere at the point.
OF THE SKULL IN GENERAL :
the bones of which it is 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 of
the soft parts, for 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 degrees. For the anatomy of
the skull is not important in itself only ; it pro¬
vides 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
h 2
100
OF THE SKULL IN GENERAL.
of all our operations. The marks which we take
of the skull, record the entrance ol artenes; the
exit of veins and nerves; the places and. uses o
those muscles which move the jaws, the throat, the
spine. Indeed, in all the human body, there is not
found so complicated and difficult a study as this
anatomy of the head; and if this fatiguing study
can be at all relieved, it must be by fhst establishing
a very regular and orderly demonsti ation of the
skull.
For this end, we distinguish the face, where the
irregular surface is composed of many small bones,
from the cranium or proper skull, 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 trans-
mit the nerves : so that the cranium is equally the
object of attention with the physiologist and with the
surgeon.
All the bones of the cranium are of a flattened
form, consisting of two tables, and an intermediate
diploe, which corresponds 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 table,
again, is dense, thin, and brittle, very easily broken,
and is sometimes fractured, while the external table
remains entire : thence it is named tabula vitrea,
or the glassy table. These tables are a little parted
from each other*; and this space is filled up
with the diploe, or cancelli. The cancelli, or '
lattice-work, have membranes, covered with vessels,
partly for secreting marrow, and partly for nourish¬
ing the bone; and by the dura mater adhering
to the internal surface, and sending in arteries,
which enter into the cancelli by passing through
of an inch, is a measure which I shall often hav<
OF THE SKULL IN GENERAL.
101
the substance of the bone, and by the pericra¬
nium 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 separa¬
tion of the dura mater is, in like manner, followed by
separation of the pericranium, which had been sound
and unhurt ; and every disease of the cancelli, or
substance of the bone, is communicated both ways;
inward to the brain, so as to occasion very imminent
danger ; outwards towards the integuments, so as to
warn us that there is disease. The general thick¬
ness 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 external table \ when we arrive at the cancelli,
there is less resistance, 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. Surgeons
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 deli¬
berately and slowly through the inner table of the
skull. But this shows an indiscreet hurry, and un¬
pardonable rashness in operation. The patient,
during this sawing of the skull, is suffering neither
danger nor pain, unless when the bone is inflamed ;
and many additional reasons lead us to refuse altoge¬
ther this rule of practice: for the skull of a child
consists properly of one table only ; or the tables are
not yet distinguished, nor the cancelli formed : in
youth, the skull has its proper arrangement of can-
_ _ o
H O
102
of the skull in general.
celli and tables ; but still, with such irregularities
and exceptions, as make a hurried operation unsafe :
in old age, the skull declines towards its original
condition, the can celli 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. I3ut, besides this gradual progress of a
bone increasing in thickness and regularity as life
advances, and growing irregular and thinner in the
decline of life, we find dangerous irregularities in
skulls of all ages. The author had specimens in his
possession where the thickness of the skull-cap varied
from nearly an inch to the thinness of common
paper. There are often at uncertain distances, upon
the internal surface of the skull, hollows and defects
of the internal table, deep pits, or foveae, as they are
called. These fovese increase in size and in number
as we decline in life : they are more frequent 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 places
considered to be the safest, perforate gradually and
slowly. Let the reader pursue this subject under
the title of the formation and growth of bones.
The BONES of the skull are divided into those
of the cranium ; the bones of the face ; and com¬
mon or intermediate bones.*
* The head is divided into the cranium and face. For the
cranium we find in old authors the words calva or calvaria, from
calvus, 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, but
of the skull in general.
The following is the usual division of the bones of
the head : —
In the adult head there are thirty bones and thirty-two teeth.
' r
Of the Cranium, Intermediate or
Six Bones. Common Bones, Two.
1 Os Frontis
2 Ossa Parietalia
or Bregmatis
2 Ossa Temporalia
1 Os Occipitis
1 Os Sphenoides
1 Os iEthmoides
' \
Bones of the Face,
Fourteen.
2 Ossa Maxillaria Supra
2 Ossa Malarum
2 Ossa Nasi
2 Ossa Palati
2 Ossa Unguis vel
Lachrymalia
2 Ossa Turbinata Infra
1 Vomer
1 Maxilla Inferior
Bones of tiie Ear,
Four on each Side, viz.
Malleus
Incus
Os Orbiculare
Stapes
Teeth.
In the child twenty.
In the adult thirty-two, viz.
8 Incisores
4 Cuspidati
8 Bicuspides
12 Molares.
We see, therefore, that the bones of which the
cranium, or skull,, is formed, by which the brain is
surrounded and protected, are in all eight in number.
1. The frontal bone, or bone of the forehead,
forms the upper and fore part of the head, — ex¬
tends a little towards the temples, and forms also the
upper part of the socket for the eye. 2, 3. 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. 4. The os occipitis is named
from its forming all the occiput or back of the head,
though much of this bone lies in the neck, and is
hidden in the basis of the skull. 5, 6. The ossa tem-
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.
h 4
01" the skull in general.
p or alia form the lower parts of the sides oi the
cranium: they are called temporal, from the hair
that covers them being the first to turn grey, mark¬
ing the time of life. 7. The os ^etiimoides, and
8. the os sphenoides, are quite hidden in the basis
of the skull: they are very irregular, and very diffi¬
cultly described or explained. The os ^ethmoides
is a small square bone, hollow, and with many cells
in it: it hangs over the nose, and constitutes a
great and important part of that organ, and at the
same time supports the brain. The olfactory
nerves, by passing through it at many points, per¬
forate it like a sieve ; and it takes its name from this
perforated or sethmoid plate. The os sphenoides
is larger and more irregular still; placed further
back; locked in betwixt the occipital and seth-
moidal bones; lies over the top of the throat, so
that its processes form the back of the nostrils, and
roof of the mouth ; and it is so placed, as to
support the very centre of the brain, and transmit
almost all its nerves.*
of the sutures of the skull.
The joinings of the bones being indented and
irregular, and like seams, they are called sutures.
1. The coronal suture is that which joins the
frontal to the parietal bones ; extends almost di¬
rectly across the head, from ear to ear ; descends
behind the eye, into the deep part of the temple;
and there, losing its serrated appearance, becomes
like the squamous or scaly suture, which joins the
temporal 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.
* Some foreign authors, as if it were to make a complex
piece of anatomy still more complicated, describe the sphenoid
and occipital bone as one, calling it os spheno-occipitalc, or os
basilare.
of the skull in genellal.
105
Q. The lambdoidal suture is that one which joins
the parietal bones to the occipital bone. It begins
behind one ear, ascends and arches over the occi¬
put, descends behind the other ear. It thus strides
over the occiput, in a form somewhat resembling 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 or squamous sutures join the
temporal bones to the parietal, occipital, and frontal
bones ; the sphenoid bone also enters into the tem¬
poral suture, just behind the eye. The temporal
suture makes an arch corresponding almost with the
arch of the external ear; it meets the coronal suture
an inch before the ear, and the lambdoidal an inch
behind it. This back part belongs as much to the
occipital as to the temporal bone; and so has been
named, sometimes additamentum sutura? lambdoi-
dalis, sometimes additamentum suturse squamosae :
for this temporal suture is, on account of the edge
of the temporal and occipital bones being thin, and
like scales of armour laid over each other, often
named the squamous or scaly suture.
5. The sphenoidal and ^ethmoidal sutures
are those which surround the many irregular pro¬
cesses of these two bones, and join them to each
other, and to the rest.
6. The transverse suture is one which, run¬
ning 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 irregularities and in¬
terruptions, that the student will hardly recognise
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:
OF THE SKULL IN GENERAL.
but this suture has not extent; it has 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, acknowledges
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 serrae or indentations, 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 small-
ness; and that it always bleeds. Indeed the older
surgeons, observing this, poured ink upon the sus¬
pected part, which, if the skull was hurt, sunk into
the fissure, and made it black and visible ; but
left the suture untouched.* The old surgeons, or
rather the ancient doctors, directed to make the
patient take a wire betwixt his teeth, which being
struck like the spring 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 cer¬
tain marks, we find a number of accidents which
may lead us into a mistake.
Sutures cannot be distinguished by their serrae or
teeth; for the temporal sutures want this common
character, and rather resemble capillary fractures
of the skull t; nor even by their places, for we know
that there are often insulated bones (ossa Wormiana)
* In matter of fact, the blood serves this purpose by its
sinking into the fissure, and giving it a dark appearance. There
is a roughness on the edge of the fissure, which, being felt by
means of the probe, will distinguish the fissure from the suture.
f Viz. Fractures as small as a hair, thence named capillary.
OF THE SKULL IN GENERAL.
surrounded with peculiar joinings, which so derange
the course of the common sutures, that the joinings
may be mistaken for fractures of the skull, and the
ossa Wormiana 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 sutures are entirely obliterated
all over the head. If the surgeon 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 com¬
monly insensible ; and even, though less hurt, his
feelings, after such an accident, must be very con¬
fused ; he must be too liable to be deceived : and
we cannot, on such slender evidence as this, per¬
form so cruel an operation as cutting up the scalp,
or so dangerous a one as the trepan.
For various reasons, we are careful to trace the
bones from their original soft and gristly or mem¬
braneous 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 form¬
ed, and for what uses. It has been remarked, that
the number of pieces in the skull is infinitely greater
in the child than in the man. These bones, ossi¬
fying from their centre towards their circumfer¬
ence, it happens, of course, that the fibres are close
at the centre of ossification, and are more scat¬
tered 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
108
of the skull in general.
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 child the bones in the head are
membraneous and imperfect. The membraneous
interstices begin to be obliterated; the sutures
are beginning to close; the distinction of two
tables is not yet established ; the cancelli are not
yet interposed between the plates; the sinuses or
caverns jjf 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 su¬
tures, but consists often of many parts. The os
frontis is formed of two pieces, which meet by a
membraneous union in the middle of the bone.
The ossa parietalia 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 tem¬
poral bones are so fairly divided into two, that
their parts retain in the adult the distinct names of
petrous and squamous bones. Although these are
all the regular points of ossification, yet sometimes
there occur small and distinct points, which form
irregular bones, uncertain in number or size, found
chiefly in the lambdoid suture, sometimes numer¬
ous 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
Wormiana, 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
9
OF THE SKULL IN GENERAL.
the adult, almost never in old age. The occipital
bones have four parts, they are close upon eacli
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, and
they never fail to form sutures by admitting into
their interstices the points and edges of the adjoin¬
ing 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 is supposed to result at
the same time, from this meeting and opposition of
the fibres and interstices 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 explained; we find each
suture always in its appointed place ; we find nothing
like a suture formed betwixt the head and body of a
long bone, though they are formed in distinct points,
and are not united till after the years of manhood; we
find no sutures when bones are broken and reunited,
when they have been spoiled, and are replaced, when
a piece of spoiled bone has been cut away, nor when
a new shaft of a bone is formed by the secreting
vessels, and is united to the heads of the old
bone. These are accidents which hold us at least
in doubt. It is, indeed, an idle mode of proceeding
110
OF THE SKULL IN GENERAL.
on such a subject, to suppose that the spinous pro¬
cesses and sutures of the skull are accidentally pro¬
duced, when design, and the most curious adaptation
of parts to their office, are very apparent. To sup¬
pose these things produced by chance, is at once to
end all enquiry, and to leave a blank in our minds.
On this subject I must refer the reader to the
dissertation in the following chapter.
It has been supposed, and, with much appear¬
ance of truth, that the sutures limit the extent of
fractures, leave a free communication of the in¬
ternal with the external parts; that they must
serve as drains from the brain ; that they are even
capable of opening at times, so as to give relief
and ease in the most dreadful diseases of the head:
but these uses of them are far from being proved.
The sutures were not intended by nature for
limiting the extent of fractures : for fractures tra¬
verse the skull in all directions; cross the sutures
with ease ; and very often, passing all the sutures,
they descend quite to the basis of the skull, where
we dare not follow them with the knife, nor apply
the trepan. Indeed we do not even know that
limiting the extent of 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. If
a certain violence and shock be committed, and
the bone does not yield, and is not fractured, yet
the vibration is propagated through it; and concus¬
sion is even more dangerous than fracture, be¬
cause it is a general injury to the brain.
Neither were they intended as drains ; for surely
it is a bold position to assume, that nature has care¬
fully provided for our making issues upon the su¬
tures. When the original openness of the head
and the membraneous condition of the sutures were
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
OF THE SKULL IN GENERAL.
sutures, to form the pericranium, and going from
that over the several joints, formed the periosteum
lor all the bones. They saw a close connection
betwixt the external and internal membranes of the
skull, and they thought that nature had intended
there a freer communication, and an occasional
drain. They found the sutures particularly wide
and membraneous 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,
fons, fontanelle, the fountain, by which they be¬
lieved 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 revul¬
sion which gave rise to them ; but both the doc¬
trines, and the practice, have been revived of late
years; and a surgeon of some eminence has been
at pains to examine various skulls, trying to find
which of all the sutures remains longest open, and
which should form the readiest and surest drain ;
and after a curious examination of each, he de¬
cidedly condemns the fontanelle; finds the addi-
tamentum 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,
though much cherished by the ancients, have been
long forgotten, and have not been effectually re¬
vived 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.
The fontanelle, or opening at the meeting of
the coronal and sagittal sutures, was once thought
112
OF THE SKULL IN GENERAL.
to be a sure mark for the accoucheur to judge by,
botli of the life of the child, and of the direction
in which its head presents. It is large and soft in
a child, and the good women lay a piece of firm
cloth upon it, and defend it with particular care.
It begins to contract from the time of birth ; and in
the second and third year it is entirely closed. Its
closing is delayed by weakness, scrophulous com¬
plaints, 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 swelling of the brain, and se¬
parate 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 cannot pass unnoticed their looseness and flexi¬
bility in the new-born child; how wonderfully the
head of the child is increased in length, and reduced
in breadth in the time of delivery, and how much
this conduces to an easy and happy labour.
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 separation
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,
confinement for many months, a temporary lame¬
ness, and sometimes being rendered unable to walk
for life.
individual bones of the skull.
113
description of the individual bones of the
skull.
OS FRONTIS. — This bone is compared with a
clam-shell. It is of a semicircular shape, hollowed
like a shell. It is divided into the frontal, nasal,
and orbitary portions, and it has within it the ca¬
vities which are named the sinuses of the frontal
bone. The frontal bone is connected by sutures
with the parietal bones, &c.
The frontal bone stands connected with the its connec-
parietal bones by the coronal suture; it is con- tl0ns"
nected to the great ala of the sphenoid bone by the its reia-
sutura spheno-frontalis ; while its orbitary plates are tlons'
united to the lesser alee by the linea sphenofron-
talis. 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 orbitary plates are seen to
be contiguous to the ossa plana of the aethmoid bone
and ossa unguis; and, lastly, the ossa malarum are
attached to the frontal bone by the extremities of the
transverse suture of the face. Its orbitary plates are Points of
two thin and diaphanous lamellae that depart from ^®™onstra"
the part of the bone which forms the forehead in a i. Orbitary
horizontal direction, so as to form a part of the socket plates-
of the eye, and a floor for supporting the anterior
lobes of the cerebrum. These two orbitary plates
leave an open space, called fissura iethmpidea. into 2- Rssura
which part of the aethmoid bone is received. aethmoidea.
The first point to be remarked is the superci- s. superd-
liary ridge, on which the eye-brows are placed: hary ndge'
it is a prominent arched line, corresponding in
size and length with the eye-brow, which it sup¬
ports : 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 4. p0res,
many small holes through which these arteries had or minute
passed. Among these, there is one hole whicli is foramma- /
vol. i. i
114
description of the
5. Superci- larger, and which is distinguished from the rest;
liary hole. ^ ^ge .g j^e tjie Q^ers, to transmit ar¬
teries to the bone, but to give passage to the frontal
nerve and a small artery which come 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. It is accompanied by the superci¬
liary branch of the ophthalmic artery. This hole is
named the superciliary hole,
g. foramen The second foramen is the foramen orbitale
°' "tat internum. It is within the orbit, near the junction
of the orbital plate with the aethmoid. It transmits
a branch of the ophthalmic division of the fifth nerve
from the orbit into the cranium, from which the
same nerve immediately passes through the aethmoid
into the nose. Sometimes there are two, when they
are distinguished by the terms anterior and posterior
orbitary foramina; but occasionally there is only a
groove, or one side of the foramen, the other being
formed by the aethmoid.
7. Angular The orbitary, or superciliary ridge, ends by two
processes. processeSj 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 angular
processes, which form the external angles of each
eye-
8. Nasal Betwixt the two internal angular processes there is
process. nasal 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 sup¬
porting the two small nasal bones ; and this gives
them a firm seat, and such a hold upon the root of
8
INDIVIDUAL BONES OF THE SKULL.
115
the forehead, that they oftener are broken than
displaced.
From the external angular process there extends 9- Tempo-
backwards and upwards the temporal ridge or spine. ral ndge'
At the inner end of the superciliary ridge, is that Em»nenti«
bump which marks the place of the frontal sinus, li^es"
which also indicates their size; for where this rising
is not found, the sinuses are wanting, or are very
small; but this is no sure nor absolute mark of the
presence of these sinuses, which often, in the flattest
foreheads, are not entirely wanting.
The sinuses* of the os frontis are two in num- 10. Sinus,
ber, one on either side above the root of the nose : es"
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 side¬
ways 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 extend some way into the pa¬
rietal bones.
The two sinuses of either side are divided by n- Parti-
a partition; but still they communicate by a small *j°"sse0Jthe
hole: sometimes the partition is almost wanting,
and there are only crossings of the common la-
mellated substance; and though the communica¬
tion with one another is not always found, they
never fail to communicate with the nose : this in¬
deed seems to be their chief use ; for the frontal
* 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, aethmoid,
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.
I 2
DESCRIPTION OF THE
sinuses are the beginning of a great train of cells,
which, commencing thus in the frontal bone, ex¬
tend through the aethmoidal, sphenoidal, and max¬
illary bones, so as to form cavities of great extent
and use belonging to the nose. These cavities ex¬
tend and give form to the face, enlarge the cavities
which receive effluvia, and allow them to circulate
and pass over the proper organ of smelling; and
they give perfection and strength to the voice. The
membrane which lines these cavities is thin, exqui¬
sitely 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 consequence to promote.
These cells, or thin membranes, are subject to
inflammation and abscess. They are also subject to
the accidental nestling of insects, which nestle there,
and produce inconceivable distress; and it is par¬
ticular, that they more frequently lodge in the fron¬
tal 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 proved, 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 peculiar to
spoiling corn ; while others have had the complaint
by sleeping upon the grass. The patient might be
relieved on easier terms than by the operation of the
trepan, which has been proposed, by the injection ot
aloes, assafoetida, myrrh, the use of snuff or smoking,
and pressing the fumes upwards into the nose.
Much should be tried, before undertaking a danger¬
ous operation on slender proofs.
individual bones of the skull.
117
It may be right in cases of fractures, to decline
applying the trepan above the sinuses, unless a frac¬
ture cannot be raised in any easier way ; and we
must be especially careful to distinguish a fracture
of the outer table only from entire fractures of this
bone. For Palfin says, that the outer table being
broken, and the natural mucus of the sinus being
corrupted and flowing out, has been mistaken for
the substance of the brain itself. And Paree, who
first gives this caution, affirms, "that he had seen
" surgeons guilty of this mistake, applying the trepan,
" and so killing their unhappy patients."*
The spine or ridge which runs upon the internal 12;Interna
surface of the frontal bone, is to be observed, as it 1'
gives a firm hold to the falx, or that perpendicular
membrane, which, running in the middle of the skull,
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 advances up the forehead, it decreases, and
often ends in a groove. The spine gives firm hold 1 3. Groove,
for the falx, and the groove lodges the great longi¬
tudinal 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 14 Fora-
of this spine, there is a small blind hole ; it is named CUm.c 1
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, ignorantly believed, that the dangerous
and ungovernable bleedings at the nose must be
through this hole, and from the fore-end, or begin¬
ning of the longitudinal sinus.
Upon the orbitary plate, and just under the super- is. ru.of
ciliary ridge, there are two depressions in the socket £.t,ocl'
of each eye : the one is very small, and deeper at the
inner corner of the eye, under the superciliary hole,
* For a more perfect account of the pathology oi the sinuses,
see Mr. John Bell's Principles of Surgery.
i 3
118
DESCRIPTION OF THE
which is the mark of the small cartilaginous pully, in
which the tendon of one of the muscles of the eye
i6. Pit for plays ; the other, a more gentle and diffused hollow,
mai gland! 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.*
On the whole, this bone affords a very important
subject of study to the surgeon, and he is especially
called to attend to the sinuses, the internal spine, and
to the orbitary processes of this bone. These orbitary
processes are the most remarkable points of this bone.
They are often fractured by a blow on the forehead,
and being extremely brittle, the splinters are beat up,
and enter the brain. They are no defence to the
brain when a weapon enters the orbit. We have
known a young man killed by the push of a foil
which had lost its guard, and which passed through
this plate into the brain.
PARIETAL BONE. — The parietal bones form
much the greater share of the cranium : they are
more exposed than any others, are the most fre¬
quently broken, and the most easily trepanned : for
the parietal bones are more uniform in their thick¬
ness, and more regular in their two tables and diploe,
Points of than any others. But the accidental varieties of pits
demonstra- anc[ 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. It enters into the forma¬
tion of the coronal, the sagittal, the lambdoidal, and
the squamous sutures.
i. The four The square form of the bone produces four angles;
and in surgery, we speak of the frontal, the occipital,
the mastoidean, and temporal angles of the parietal
bone. It has deeply serrated edges which unite the
* In addition, as points of demonstration, we may add the
eminentice frontcilcs. See the general review of the skeleton.
INDIVIDUAL BONES OF THE SKULL.
119
two bones with each other, and with the occipital
and frontal bones. All the corners of this bone are
obtuse, except that one which lies in the temple, and
which, running out to a greater length than the other
corners, is sometimes named the spinous or temporal 2. Spinous
process of the parietal bone, though there can be no sphenoidal
true process in a bone so regular and flat. The lower angle,
edge of the bone is a neat semi-circle, which joins
the parietal to the temporal bone ; and the edge of e
each is so slanted off, that the edge of the temporal
overlaps the edge of the parietal, with a thin scale
forming the squamous suture. About an inch above
the squamous suture, there is a semi-circular ridge,
where the bone is particularly white and hard ; and
rays extend downwards from this, converging towards ^*1^{npo"
the jugum. The white semi-circular line represents rd n ge'
the origin of the temporal muscle; and the converg¬
ing 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 meeting of the two parietal bones, nus.
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 6. Groove
bone at that angle of it which lies in the temple.
It traverses the bone from corner to corner, spreading tery.
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 sometimes 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 7. Foramen
small and round, is within one inch of the meeting Panetale-
of the lambdoidal and sagittal sutures, and gives
passage to a small external vein, which goes in-
1 4
120
DESCRIPTION OF THE
wards to the sinus, and to a small artery, which
goes also inwards to the dura mater, or rather to
the falx.
s. Fovea. On the inner surface of the bone, and commonly
near the sagittal edge, we very often see pits or fovea?,
which receive those bodies which are called glands,
of the dura mater.
9. Fossa of The lateral sinus makes a depression on the inside
the amus. mastoidean angle.
The meeting of the frontal and parietal bones,
being imperfect in the child, leaves that membra¬
neous 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 for the
moisture from the brain : and so the parietal bones
are named ossa bregmatis. The parts of these bones
which form the upper portion of the skull are
equable in their thickness, and there the surgeon
would apply his trephine, if he had it in his power to
choose ; but towards the temporal angle he would
apply it unwillingly, because of the meningeal artery,
which is apt to be opened, and to be at least trouble¬
some. Formerly, surgeons were forbid to trepan
over the longitudinal sinus : now the fashion is
altered, and some surgeons would persuade us to
prefer it! We do it when necessary, but always with
due consideration of the great vein or sinus.
For an account of the veins contained within this
bone, see the concluding observations on the bones of
the cranium, and under the head of Emmissarice.
OS OCCIPUTS has also the names of os me¬
moriae and os nervosum. It is the thickest of the
cranial bones, but 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
* The word pulsatilis, or fons pulsatilis, or beating fountain,
was added, because we feel the beating of the arteries of the
brain there.
individual bones of the skull.
121
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
lambdoidal suture, to the mastoidean portions of the
temporal bone by the additamentum suturse lamb-
doidalis, 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
sphenoid bone, by that peculiar bond of union called
synostosis.
In beginning the demonstration, we point out its p0ints of
divisions : 1. Pars occipitalis. 2. Pars lateralis or con- demonstra
dyloidea. 3. Pars basilaris or cuneiformis; 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 angles.
The external surface is exceedingly irregular,
by the impressions of the great muscles of the neck :
betwixt the insertions of the muscles, projecting
lines are on the bone. In the middle of the bone, i. p§pen-
and betwixt the muscles of opposite sides, there runs ex-
a ridge from above downward; at the upper margin spine,
of the insertion of the trapezius, there is formed a 2. Superior
superior transverse spine or ridge, and in the same J"®verse
way, directly above the insertion of the recti, which
make two irregular depressions, there is an inferior 3. inferior,
transverse spine. In a strong man, advanced in
years, where the ridges and hollows are strongly
marked, at the point where the superior transverse
crosses the perpendicular one, it is so very prominent, 4. Tllber_
as to be named the posterior tuberosity of the osity-
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-externum is a diaphragm or f;u^t1crnal
transverse partition, which crosses the skull at its Hdgcl
122
description of the
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 ridge of the occipital bone. In the angle
where this membrane is fixed to the ridge, lies the
great sinus or vein, which is called the longitudinal
sinus, while it is running along the head; but the
same sinus, dividing, in the back of the head, into two
great branches, changes its name with its direction ;
and the forkings of the vessel are named the right
and left lateral sinuses, which go down through the
basis of the skull; and being continued down the
neck, are there named the great or internal jugular
6. Grooves veins. This forking of the longitudinal into the
for the si- lateral sinuses, makes a triangular or tripodlike
n uses*
groove, which follows the internal ridges of the
occipital bone : and above and below the transverse
ridge there are formed four plain and smooth hollows.
7. Fossa ce- The two upper ones are above the tentorium, and
rebeiii, and con£ain t]ie posterior lobes of the brain : the two
fossa cere- r . 7
bri. lower ones are under the tentorium, and hold the
lobes of the cerebellum or little brain.
«. Cunei- Processes. — The processes or projections of the
cess? pr°~ 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 occipital to the sphe¬
noidal 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 cuneiform, or wedge-like pro-
9. Fossa cess of the occipital bone. On the inside of this part
basiiaris. 0f the bone is a slight hollow, to which the name of
Lateral fossa basiiaris is given, and lateral to this the groove
groove. of the lower petrous sinus may be observed. And
10. Con- there are two small oval processes, or button-like
dyles' projections, which stand off from the side, or rather
from the fore-part of the foramen magnum, or great
hole, and which, being lodged in sockets belonging to
individual bones of the skull.
123
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 corresponding bone of the
neck.
On the lower part of the cuneiform process, there 11. Tuber-
are two tubercles for the attachment of the recti the
capitis anteriores. Near the condyle, and immediately process""
behind the foramen lacerum, there is a tubercle for 12. Small
the rectus capitis lateralis. berdel.4""
Holes. — These condyles stand just on the edge 13. fora-
of the foramen magnum, or great hole of the skull, metl ma£-
i-i • 1 • • num.
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 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 in part a sheath for the
spinal marrow, and a ligament for each individual
bone. There pass down through this great hole the
spinal marrow, and the vertebral vein; there come up
through it the vertebral arteries, which are of great
importance and size ; and a 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 14. For3-
of the foramen magnum, and, just at the root of
either condyle, is round and large, easily found, and anted!!
sometimes it is double ; it transmits the ninth pair,
or great lingual nerve.
There is another hole smaller, and less regular than 15. Poste-
tliis last. It is exactly behind the condyle, while the rius*
124
description of 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 ; sometimes it is a hole common to
the temporal and occipital bones, but often it is not
found, and this trifling vein gets in by the great
occipital hole.
i6. Pan of We shall describe with the temporal bone that
iacer°um"U" wide hole which is common to the temporal and
occipital bones, and which transmits the great lateral
sinus, and the nerves of the eighth pair.
The surgeon would do well to study, with great
care, the place of the posterior tubercle, and to teach
himself to calculate the place of the sutures from
their protuberance, and as it were from the same
land-mark, to estimate the place of the internal spines,
and the fossa cerebrales; for these inequalities in
the thickness of this bone become of the first con¬
sequence in applying the trephine to the back of the
head.
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
parssqua- 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 as it were by
Pars pe- the rubbing of the temporal muscle. The pars pe¬
trosa, often named os lapidosum, or stony bone, is
hard, irregular, rocky ; juts inwards towards the basis
of the skull; contains the organ of hearing, and, of
course, receives and transmits all the nerves which
are connected with the ear.* There is a third portion
Mastoidean of this bone, viz. the mastoidean angle, which is
angle. 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 squa¬
mous suture; is scolloped or fringed; and exceedingly
* The anterior and posterior semi-circular canals are protu¬
berant upon its surfaces.
individual bones of the skull.
125
thin on its edge ; it is radiated, in consequence of
its original ossification shooting out in rays. The
petrous part again is triangular, unequal by the
cavities of the ear ; it has a very hard, shining,
polished-like surface; exceeded in hardness by no¬
thing but the enamel of the teeth. Where it projects
into the base, it has several open points, which are
filled up with cartilaginous or ligamentous sub¬
stance ; and its occipital angle is connected with the
other bones by the additamentum suturas squamosae.
The temporal bone closes the cranium, upon the
lower and lateral part; backwards it is connected by
the additamentum suturae lambdoidalis to the occipital
bone; by the squamous suture and the additamentum
suturffi squamosa, it is joined to the parietal bone ;
whilst anteriorly it is united to the sphenoid bone by
the spheno-temporal suture, the spinous process of
the sphenoid bone being deeply wedged betwixt
the petrous and squamous portions of the temporal
bone.
Processes. — The zygomatic process rises broad 1. zygoma-
and flat before the ear ; grows gradually smaller as tlc process'
it stretches forward to reach the cheek-bone : it forms
with it a zygoma, yoke, or arch of the temple, under
which the temporal muscle plays. The temporal
muscle is strengthened by a firm covering 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 dis-
tortor 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 2. styloid
resemblance to the stylus, or point with which the process-
ancients engraved their writings on tables of wax.
It is cartilaginous long after birth ; even in the adult,
it is not completely formed ; it is exceedingly delicate
and small ; and when its cartilaginous point is fairly
ossified, as in old men, it is sometimes two inches
126 description of the
long. It stands obliquely out from the basis of the
head, and is behind the jaws; so that it gives con¬
venient 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 expanding
over the pharynx, is called stylo-pharyngeus; one
going to the os hyoides, is the stylo-hyoideus; 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.
3. vaginal Processus vaginalis will not be easily found, nor
process. acknowledged 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 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.
4. Mastoid PROCESSUS MASTOIDEUS, 01* MAMMILLARIS, is a C0-
process. nical 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 cavity of the ear, and
are thought to reverberate and strengthen the sound.
Groove for Under its root there is a deep and rough rut which
«' gives a firm hold to the first belly of the digastric
muscle : and the point or nipple of this process is
the point into which the mastoid muscle is inserted
from before ; and the complexus, obliquus and tra-
clielomastoideus muscles from behind.
5. Auditory The auditory process is just the outer margin
process. Gf 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,
* In brutes it is? indeed, a process standing out.
INDIVIDUAL BONES OF THE SKULL.
127
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 fairly united to the bone, and is named the
processus auditorius; and may be defined a circle,
or ring of bone, with a rough irregular 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
mammillary to the root of the zygomatic process.
Betwixt this and the mastoid process there is a
kind of fissure, the rima niastoidea.
The lower jaw is articulated with this bone by 6. Articular
a shallow fossa, which is anterior to the auditory fossa-
process, and at the root of the zygomatic process.
A tubercle immediately before this articulating 7. Articular
surface deepens it. A fissure may be observed in ^Fissure,
nearly the middle of the cavity, which is for the
attachment of the ligament which unites the inter¬
mediate cartilage of this articulation. This fissure
divides the proper articular or glenoid cavity from
that fossa which gives lodgment to a deep portion
of the parotid gland.
Holes. — The temporal bone is perforated with
many holes ; some for permitting 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 9- Meatus
which has been described) is that deep tube which ^SmuT
in the dry bones leads to the interior cavity, the tym¬
panum, but which is closed at the bottom by the
membrane of the tympanum in the living body.
The MEATUS AUDITORIUS INTERNUS is that hole Inter-
by which the auditory nerves have access to the nus'
ear. It is a very large hole seated upon the
back of the pars petrosa. 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 nerve of the 7th pair
is double from its very origin in the brain : it con¬
sists, in fact, of two distinct nerves, the portio dura,
128
description of the
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
into 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 ex¬
panded ; 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 dis¬
tinct canal, the aqueduct 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 cavity of the ves¬
tibule, is expanded in these cavities to form the
proper organ of hearing.
11. Videan There is a small hole which will admit the point of
foramen. 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.
12. stylo- The hole by which the portio dura passes out
foramen upon the cheek, is found just before the mastoid,
and behind the styloid process ; and being betwixt
the two, it is named the stylo-mastoid hole,
is. Eusta- The hole for the Eustachian tube is very irre-
chian tube, gular. No air can pass through the membrane of the
drum ; and as air is necessary within the ear, it is
conveyed upwards from the palate by the iter a
palato ad aurem, or, as it is commonly called, the
Eustachian tube. This tube is long, and of a
INDIVIDUAL BONES OF THE SKULL.
trumpet form ; its mouth, by which it opens behind
the nostril, is wide 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 rotted 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.
Above and to the outside of the Eustachian tube *4- Canal
i li-i i °* t"e corda
there is a narrow canal which conveys the nerve tympani.
called corda tympani. This nerve, traversing the
tympanum, enters into the aqueduct of Fallopius,
and unites with the facial nerve.
On the inside of the Eustachian tube we may
observe a canal which, leading backwards, opens muscle 0f°
into the cavity of the tympanum with a mouth like themalleus-
a spoon ; it gives lodgment to the long muscle of
the malleus.
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, i6. Carotid
enters into the skull near the point of the petrous foramen>
bone, and just before the root of the styloid process.
The artery goes first directly upwards, then obliquely for the pas-
forwards through the bone, and then again upwards, sageofthe
o o _l / Great arterv
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. It
is at this particular point that we are sensible in our
own body of the beating of these two great arteries ;
and Haller informs us, that, during a fever, he felt
this beating in a very distressing degree. The sym- sayn^pf°"he^
pathetic nerve accompanying the carotid artery is nerve,
also transmitted through this canal.
The great lateral sinus comes out in part ^n^"
through the temporal bone, to form the internal rum pos-
130
DESCRIPTION OF THE
jugular vein. The course of the sinus may be easily
traced by the groove of the occipital bone down-
transmits wards, behind the pars petrosa : there also it makes
juguiar^rnal a deep groove, and ends with a large intestine-like
turn, which makes a large cavity in the temporal
bone, big enough to receive the point of the finger.
The sinus passes out, not by any particular hole in
the temporal bone, but by what is called a common
hole, viz. formed one half by the temporal and one
half by the occipital bone. This hole is very large;
is lacerated or ragged-like. It is sometimes divided
into two openings, by a small point, or spine of bone.
The larger opening on one side of that point trans-
and the mits the great sinus, where it begins to form the
thl^Tghth jugular vein ? an(i tfie smaller opening transmits the
pair. ° eighth nerve of the brain.
is. Mastoi- There is a small hole on the outside of this bone,
dean fora- -n occjpjta] angle . or rather the hole is oftener
found in the line of the suture (the additamentum
suturse squamosa). Sometimes it is in the occipital
bone ; or sometimes it is wanting : it transmits a
trifling vein from without, into the great sinus, or a
small artery going to the dura mater.
19. Ducts of There are two very small canals, which carry
o unmus. kiooc[_ vessels anc[ lymphatics from the inner cavities
of the ear ; they have been called aqueductus vesti-
buli, and aqueductus cochleae ; they open on the
posterior surface of 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 already mentioned on the mastoid process
for the lodgment of the head of the digastricus;
certain cerebral fossse, which are the impressions of
the convolutions of the brain upon the inside 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 lodgment of
the temporal muscle ; and, lastly, we observe in a
well-marked bone, the sulci for the artery of the
dura mater, and the groove for the petrous sinus on
INDIVIDUAL BONES OF THE SKULL.
the ridge which divides the surfaces of the petrous
bone.
The temporal bone is important as a bone of the
cranium, and lying in contact with the membranes
of the brain. It is subject to scrofulous disease,
from containing the complicated organ of hearing.
Its diseases not only affect the brain, but in a par¬
ticular manner influence the muscles of the face, from
the nerves transmitted being those of expression.
In concluding the description of the bones of the
cranium, I should not omit to state, that all these
bones are hollowed out into canals for veins — a
late discovery of M. Breschet, of the Hotel Dieu.
These veins run in the diploe, and are of a size that
makes the surprise the greater they should have been
so long neglected. These channels are numerous
in the frontal and occipital bone ; but they are
very conspicuous and regular in the parietal bone.
They converge towards the temple considerably
behind the course of the meningeal artery. They
are to be demonstrated by filing off the external
table of the bone. Do these internal and concealed
channels determine the course of fractures of the
skull? Are these internal veins ever the seat of
tumor ? *
The iETHMOID 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 consisting of many convoluted
plates which form a net-work like honey-comb. It
is curiously enclosed in the os frontis, betwixt the
orbitary processes of that bone. One horizontal
plate receives the olfactory nerves, which perforate
that plate with such a number of small holes, that
it resembles a sieve, whence the bone is named
cribriform, or sethmoid bone. Other plates, dropping
perpendicularly from this one, receive the divided
* See Recherches Anatomiques sur les Canaux veinaux des Os
Par M. Breschet.
K 2
132
description of the
Connec¬
tions.
Processes.
1. Cribri¬
form plate.
2. Crista
galli.
nerves, and give them an opportunity of expanding
into the organ of smelling ; and these bones, upon
which the olfactory nerves are spread out, are so
much 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, for the rolling of the eye, is
named the os planum, or smooth bone ; so that the
aethmoid bone supports the fore part 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
aethmoid bone. Thus the aethmoid is united to the
frontal bone, by the linea aethmoidea frontalis, and
to the sphenoid bone by a similar line of contact,
visible on the inside of the base of the cranium.
Looking into the orbit, we again see a union with
the frontal, and with the sphenoidal and palate bones.
Its perpendicular plate stands connected to the back
part of the nasal process of the frontal bone; the
vomer is attached to the back part of this plate.
The ossa unguis close the cells of this bone ante¬
riorly. In the foetus the aethmoid bone is divided
into two by a cartilaginous partition, which becomes
afterwards the perpendicular plate and crista galli.
The cribriform plate is exceedingly delicate and
thin, lies horizontally over the root of the nose, and
fills up neatly the space betwixt the two orbitary
plates of the frontal bone. The olfactory nerves,
like two small flat lobes, lie out upon this plate, and,
adhering to it, shoot down like many roots through
this bone, so as to perforate it with numerous small
holes, as if it had been dotted with the point of a pin,
or like a nutmeg-grater.
This plate is horizontal; but its processes are per¬
pendicular, one above, and three below.
The first perpendicular process is what is called
crista galli, a small perpendicular projection some¬
what like a cock's comb, but exceedingly small,
INDIVIDUAL BONES OF THE SKULL.
133
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. 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 some¬
times, it is said, hollow or cellular.
Exactly opposite to this, and in the same direction 3. Nasal
with it, i. e. perpendicularly to the asthmoid plate, pldte'
stands out the nasal plate of the asthmoid bone.
It is sometimes called the azygos, or single process
of the asthmoid, 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
azygos process is united with the vomer, which
forms the chief part of the partition; so that the
septum, or partition of the nose, consists of this
■azygos process of the asthmoid bone above, of the
vomer below, and of the cartilage in the fore or
projecting part of the nose; but the cartilage rots
away, so that 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 consist of 4.Theiaby-
a series of cells communicating with each other, and rlnth'
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 5. Processes
a spongy bone, one hanging in each nostril. They ^spongy
are each rolled up like a scroll of parchment; they bones,
are very spongy; are covered with a delicate and
sensible membrane, and when the olfactory nerves
depart from the cribriform plate of the aethmoid bone,
they attach themselves to the septum, and to these
k 3
134,
DESCRIPTION OF THE
upper spongy bones, and. expand upon them so, that
the convolutions of these bones are of material use
in expanding the organ of smelling, and detaining
the odorous effluvia till the impression 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.
6. Os pi a- The orbitary plate of the aethmoid bone is a large
niim. surface, consisting of a very firm plate of bone,
of a regular quadrangular 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.
The os un- The os unguis should also, perhaps, be counted
gu,s' as a part of the bone ; for though when observed in
the orbit, it 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 is a small
scaly-like plate, in the inner corner of the orbit just
over the nose, wrhich closes the cells of the aethmoid
bone; however, it will be described below as a dis¬
tinct bone.
The cells of the aethmoid bone, which form so
important a share of the organ of smelling, are ar¬
ranged 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 belongs in like manner
individual Bones of the skull.
135
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 con¬
nections and forms of the bone, we can easily under¬
stand how the venereal ulcer, when deep in the nose,
having got to these cells, cannot be cured, but under¬
mines all the face ; how the venereal disease, having
affected 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 partition, might depress the de¬
licate cribriform plate, so as to oppress the brain
with all the effects of a fractured skull, and where
no operation could give relief. And we also see
much danger in pulling away polypi, which are
firmly attached to the upper spongy bone.
SPHENOIDAL BONE. —The sphenoidal bone
completes the cranium, and closes it below. It is
named sphenoid, cuneiform, or wedge-like bone,
from its being incased in the very basis of the skull ;
or it is named os multiforme, 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 pterygoid bone : its temporal processes
being like extended wings ; its proper pterygoid pro¬
cesses 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 centre 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
* The number is commonly twelve, but not regularly so.
k 4
136
DESCRIPTION OF THE
are always, in describing this bone, moving forwards
from point to point, from one process or hole to the
next.
Points of Processes. — The aue, or wings, often named
demonsi™- temporal processes, rise up in the temple, to form a
i. Great part of the hollow of the temple ; and the wings of
alae- the sphenoid bone meeting the frontal, parietal, and
temporal bones, by a thin scaly edge, they make
its surfaces, part of the squamous suture, and give a smooth
surface for the temporal muscle to play upon.
2. Orbital 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 aethmoid 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
sphenoid bone, or orbitary plate of the great alse.
3. Cerebral. The surface of the great wing which looks back-
ward receives the middle lobe of the cerebrum, and
4. and Tern- is called the cerebral fossa ; and that which is ex-
porai fossae, ternal and receiving the temporal muscle, is called
the temporal fossa.
5. Spinous The lower, or back part of this bone runs out into
process. a narrow which sinks in under the petrous
portion of the temporal bone, and being sharp point¬
ed, it is named the spinous process. It is very re¬
markable for a small hole which permits the great
artery of the dura mater to enter.
6. styloid The point of this spinous process projects in the
process. 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.
7. wing of The lesser wing of Ingrasias next attracts the
Ingrasias. 0ye It is that part of the bone which unites (by
harmonia) with the orbitary plate of the frontal bone,
and with the sethmoid bone.
8. Trans- This lesser wing projects laterally into the trans-
™; verse SPINOUS PROCESS.
individual bones of the skull.
137
The pterygoid processes * are four in number, pterygoid
two on each side. They are those processes upon processes-
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 ex¬
ternal pterygoid, the other is named the internal
pterygoid process.
Each external pterygoid process is thill and 9.External,
broad, and extends farther backwards. Each inter- 10. inter-
nal pterygoid process is taller and more slender, nal*
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 n. hamu-
process). The inner pterygoid processes form the lar process-
back of the nostrils. The hook of the pterygoid
process is called the hook of the palate, of which it
forms the backmost point. The musculus circum-
flexus 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. Betwixt the two processes 12. Fossa
there is a hollow which is called the fossa pterygoidea, j^17201'
and at the root of the internal pterygoid process
there is a groove which leads to the mouth of the
Eustachian tube.
The azygos process t is so named, from its being 13. Azygos
single, because it is seated in the centre of the bone, process-
so that it can have no fellow. It stands per¬
pendicularly downwards and forwards, over the
centre of the nose, and its chief use is to give a firm
"* There is some confusion in this name, since pterygoid sig¬
nifies alform or wing-like processes.
f Azygos is a term which is applied to such parts as have no
fellow; because 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 other¬
wise single, we call them azygos, and so the azygos process of
the sethmoid and sphenoid, and other bones; or the azygos
vein, which runs in the centre of the thorax, and is single.
138
description op the
seat or insertion for the vomer or bone, which forms
the septum. The vomer, or proper bone of the
partition, 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.
14. ante- The clynoid processes have, like many parts of
rior ciynoid £]ie hurrian body, a very whimsical name, very ill-
procisses. gu^e(j £0 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 processes
are very remarkable. The two anterior clynoid
processes are small bumps, rather sharp, projecting
backwards, and terminating in two flat projecting
15. Poste- 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 two points,
small and round, or knobby at their points; and
they look forwards towards the anterior clynoid
processes.
16. Tuber- The tuberculum olivare is an eminence betwixt
the anterior clynoid process and before the sella
turcica.
17. Sella The sella turcica, ephippium, or Turkish saddle,
is the space enclosed by these four processes, and is
well named. The sella turcica, supports the pitui¬
tary gland, an appendage of the brain, the use of
which is unknown. The carotid arteries rise up by
the sides of the sella turcica, and mark its sides with
a broad groove. The optic nerves lie upon a groove
at the fore-part of the sella turcica, 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 lies. Often the posterior clynoid
knobs cannot be fairly distinguished ; since, in many
skulls, they form but one broad process,
is. Depres- On the side of the posterior clynoid process, the
carotid!" carotid artery as it rises impresses its form upon the
bone.
INDIVIDUAL BONES OF THE SKULL.
139
The cone, or triangular process, is singularly 19- Trian-
i t • i ^' a ' o ^ %/ o*iiIa.r pro-
placed m obscurity, when the bones are in union, Cess.
and in separating the sphenoid bone it is very 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 20. Sphe-
we call the body of the bone, all the sella turcica, noid ce11,
that space which is betwixt the clynoid processes
within and the azygos process without, is hollowed
into one large cell, divided with a middle partition.
It is, indeed, less regular than the other cells ; it is
sometimes very large, sometimes it is not to be
found ; it has other trifling varieties which it were
idle to describe. As it communicates with the seth-
moid cells, it probably performs one office with them,
is almost a continuation of them, so that when any
one is less or wanting, the others are proportionably
larger.
I11 the foetus there is no sphenoid cell; and the
great alae can be separated by maceration.
HOLES. — The sphenoid bone is so placed in
the very centre of the skull, that its holes transmit
the principal nerves of the skull, and it bears the
marks of the chief arteries.
The optic holes are large round holes, just under 21. Optic
each anterior clynoid process. We trace the optic foramen-
nerves by a large groove into each optic hole ; and
an artery goes along with them, named the ophthal¬
mic 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
especially 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 of this ophthalmic
artery, which goes out upon the forehead, through
the superciliary notch, or hole.
The foramen lacerum anterius is next in order, ^fora-
and is so named because it is a wide slit. It is also rum.
140
description of the
called superior orbitary fissure. The foramen lace-
rum is wide near the sella turcica, grows gradually
narrower, as it goes out towards the temple, till it
terminates almost in a slit. The upper line of the
foramen lacerum is formed by the transverse spinous
process, extending outwards, sharp and flat.
The nerves of the skull are counted from before
backwards. There are nine nerves, proper to the
skull; the first, or olfactory nerve, perforates the
cribriform bone; the second, or optic nerve, passes
through the optic hole ; the third, fourth, part of the
fifth, and sixth 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 third, fourth, fifth,
and sixth pairs, go to animate its muscles or bestow
sensibility, and, passing through the orbit, to mount
upon the forehead, or go downwards into the nose.
23. Fora- The foramen rotundum is named from its round
dum.r° un~ 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 enumerate the branches of
the fifth 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 fifth pair. The
first branch of the fifth pair is destined for the eye ;
the second branch of the fifth pair for the upper
jaw ; the third branch of this fifth pair for the lower
jaw : so the first branch of the fifth pair passes
through the foramen lacerum to the eye j the second
branch of the fifth pair passes through the foramen
rotundum to the upper jaw ; the third branch of this
great nerve passes through the foramen ovale to the
lower jaw.
The foramen rotundum, then, is a hole exactly
round, pretty large, opening immediately under the
inner end of the foramen lacerum, and transmitting
the second branch of the fifth pair of nerves to the
upper jaw.
individual bones of the skull.
141
The foramen ovale is an oval hole, larger than ^fora-
the foramen rotundum ; about half an inch behind
it: and transmitting the third branch of the fifth
pair to the lower jaw.
The foramen spinale, or spinous hole, is a very 25. Fora-
small round hole, as if made with a large pin ; is in spi~
the very point of the spinous process ; is one third
oi an inch behind the oval hole, and transmits the
small artery, less than a crowrquill, which constitutes
the chief artery of the dura mater, viz. that artery
which makes its impression upon the parietal bone.
There is still another hole, which transmits a nerve 26- Fora~
, . . „ men ptery-
cunous in this respect, that it is not going out irom goideum.
the skull, but returning into it: for the second
branch of the fifth 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 seventh
pair, and in its way gives a small branch, to help out
the slender beginning of the great sympathetic nerve.
This retrograde branch of the superior maxillary
nerve gets back again into the skull, by a hole which
is found just under the root of each pterygoid pro¬
cess, whence it is named pterygoid hole : or, by
many, is named after its discoverer, the Vidian hole.*
This hole is almost hidden under the point of the
petrous bone ; is not to be seen unless in the sepa¬
rated bones, and is nearly of the size of the spinous
hole.
If there are found some minute holes about the 27. Irregu-
sella turcica, thev are the marks of some blood-vessels ^fora"
1 • -i • mina.
entering the bone to nourish it.
When the bones of the cranium are united, there common
is apparent an irregular hole, which corresponds well foramilia-
with the name foramen lacerum medium. It is the 28. Fora-
continuation of the carotid foramen, but belongs j^c;
equally to the sphenoid, temporal, and occipital dium.
* This retrograde twig is the little nerve which perforates the
os petrosum on its fore part. Vidus Vidius was a professor of
Paris, and physician to Francis the First.
142 of the bones
bones. The petrous portion of the temporal bone
points to it.*
29.Spheno- There is a second common hole formed betwixt
fissure?17 the sphenoid, the maxillary, and cheek-bone. It is
called the spheno-maxillary fissure.
There is a third common hole betwixt the cell of
the palate-bone (in the separate bone a groove may
be noticed on the back part of this cell) and the root
so. Spheno of the pterygoid process. This hole transmits an
fissure.6 artery, and a twig of the fifth pair of nerves, into the
membrane of the nose.
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 com¬
mon name of upper and lower jaw. There are bones
on either side of the face, and a central or azygos
bone: 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, concerning the sutures of the face,
that they are acknowledged to be purely a conse¬
quence of the ossification having begun in many
points : no particular design of nature has been sup¬
posed. The sutures, if they require names, are to be
named after the bones which they unite together.
* It is called medium because there is a foramen lacerum
betwixt the temporal and occipital bones which make three of
that name.
OF THE FACE AND JAWS.
143
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 attach¬
ment 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 called, the bridge) of the
nose; from which connection, notwithstanding its
firmness, the cartilages are sometimes luxated.
The only point like a process in these bones is,
that rough ridge formed by their union which pro¬
jects towards the cavity, to give attachment to the
nasal plate of the sethmoid bone.
Os unguis, so named from its being of the size
and shape of the nail of the finger; or sometimes
named the os lachrymale, from its holding the
duct which conveys the tears, is that thin scale of
bone which I have described as belonging to the os
eethmoides. It is commonly described as a distinct
bone; it is a thin flat bone, a single scale, without 1. Ridge.
any cancelli, having only one sharp ridge upon it; it
forms a groove for lodging the lachrymal sac, and is 2. Groove.'
of course found in the inner angle of the eye at its
fore part, and just touching the top of the nose. One
half of this bone is behind the groove, and there the
eye rolls upon it. One half of it is occupied by the
groove for the nasal duct; and the other side of the
groove is formed by the rising branch or nasal pro¬
cess, as it is called, of the upper jaw-bone. The os
unguis is delicate, and easily broken, being as thin as
144
of the bones
a sheet of paper. It is this 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 caution is to perforate in the place of the
groove, as that will lead into the nose, and not
behind it, which would carry the perforating instru¬
ment into the ^ethmoidal sinuses, and perhaps wound
the spongy bone ; nor more forward, as that would
be ineffectual from the strength of the nasal process
of the maxillary bone.
This bone seems peculiarly liable to caries, which
is perhaps 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 curious in the face.* even to its size
and shape. The upper jaw-bones are of a very great
size, forming, as it were, the foundation or basis of
the face. They send a large branch upwards, which
forms the sides of the nose ; a broad plate goes back¬
wards, which forms the roof of the palate. There is
a 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
face; and the diseased enlargement of this cavity
raises the cheek-bone, protrudes the eye, and deforms
the face in a very extraordinary degree.
These processes, and this cavity of the bone, are
what deserve most particular notice.
Surfaces. The surfaces or plates of the bone are these: ex¬
ternal or malar; the superior or orbital; the internal
or nasal; the inferior or palatine.
Connec- From this description we shall understand the
tl0ns" connections of the bone. It is attached forward and
upward to the nasal and frontal bones; laterally to
the cheek-bone, and in the orbit it is connected with
of the face and jaws.
145
the lachrymal and aethmoid 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 ex- i- nasai
tends upwards to form the side of the nose. It is pioccss-
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 2. internal
nasal process there is a rough horizontal ridge, which ndge'
gives attachment to the fore part of the inferior
spongy bone.
A plate of this bone is called the orbitary process. 3. Orbitary
This thin plate is the roof of the great cavity, which platc"
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 infra-orbit-
surface of this plate, in which the chief branch of ary cana1'
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- 4. Malar
bone stands ; and that it may have a firm place, there process-
is a rough and (as anatomists call it) scabrous sur¬
face, of a triangular shape, which makes a very firm
suture with the cheek-bone ; and as this surface rises
a little, it is named the malar process.
From the lower circle of the upper bone there pro- 5. Alveolar
jects a semicircle of bone, which is for lodging the proccess-
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 (processus alveo-
laris), 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
VOL. 1. l
146
of the bones
extremely thin, and surround them closely. The
teeth are so closely embraced by their sockets, and
we are so far from being possessed of any instrument
by which they can be pulled perpendicularly out,
that the sockets can seldom escape; they are broken
or splintered in perhaps one of four extractions, even
by the most dexterous artists in that line,
e. palate The palate process is a plate of bone which
process. 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 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
its suture, 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
7. Nasal separated, nor easily joined again. This meeting of
sPme. t|ie paiate-plates by a broad surface makes a rising
spine, or sharp ridge, towards the nostrils, 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 vomer, or partition of the nose, is planted.
Thus we find the palate-plate of the maxillary bones
conjoined, forming almost the whole of the palate,
while what are properly called the palate-bones form
a very small share of the back part of the roof of the
mouth. As these thinner bones of the face have no
marrow, they are nourished by their periosteum
only ; they are of course perforated with many small
holes. A great many minute holes are found along
the palate-plate, about the place of the sockets, 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
of the face and jaws.
147
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 fades interna " 1 tc
nasalis as an internal nasal plate. This is the
side of the bone which is towards the cavity of the
nose, on which the lower spongy bone hangs, and
which is perforated to allow a communication betwixt
the great cell and the nose.
The antrum maxillare, or cavity of the jaw-bone, 9. Antrum
is commonly named antrum Highmorianum, after maxillare-
its discoverer, Highmore. We have gone round the
antrum on all its sides, in describing these processes
of the bone : the palate-plate makes the floor of the
antrum; the orbitary process makes its roof; the
cheek, quite up from the sockets of the teeth to the
lower part of the eye, forms its walls or sides: so
that when the antrum enlarges, it is the cheek that
becomes deformed; and when we design to open
the antrum, we either perforate its anterior surface
within the cheek, or pull one of the teeth. The
antrum is round towards the cheek, but it has a flat
side towards the nose ; it is divided 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 open¬
ing ; but in the skull, covered with its soft parts, we
find the antrum almost closed by a membrane wThich
stretches over 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 iismem-
antrum, like the inner surfaces of the nostrils, is brane"
covered with a membrane, and is bedewed with
mucus ; and the mucus drops more or less freely in
various positions of the head. Sometimes by cold or
other accidents, inflammations and swellings of the
membrane come on ; the holes are closed ; the drain
of matter is suppressed and confined within, and the
cheek swells. Perhaps there may be some particular
l 2
148
OF THE BONES
disease of the membrane 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
deformed. Sometimes the matter makes its way by
the sides of the teeth, or at last it bursts through the
bones, makes an ulcer in the cheek ; and then there
is a natural cure, but slow and uncertain. There is
no very sure mark of this disease ; it may be known
by an attentive retrospect of all the circumstances.
The disease is not to be easily nor certainly 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
Root of the 0f the cheek, are very suspicious signs. The pulling
kriTpro.0 of the second or third of the grinding teeth, often
jects into it. 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 introducing a
sharp stilet by the socket of the tooth that is pulled.
The flow of the matter gives relief, and injections
complete the cure. But as this opening is sometimes
a cure, it is sometimes also a disease ; for the break¬
ing 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.
Foramina. Holes. — There is only one perfect hole in this
bone ; but, by its union with other bones, it forms
10. infra- four more : the infra-orbitary hole, for transmitting
hoie!ary the infra-orbitary nerve from the bottom of the eye,
is the opening of the canal which comes along under
the eye. It is just under the margin of the orbit,
or sometimes the nerve which it transmits, divides,
and makes two smaller holes in its passage upon the
cheek. A hole in the palate-plate, which belongs
C
OF THE FACE AND JAWS.
149
equally to each of the maxillary 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 11. Fora-
just behind the incisive or cutting teeth ; or it is ™e^mcisl~
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-bone. It is formed on the back part of the
palate (one on either side), in the suture which joins
the palate-bones to the iaw-bones : it is named pos- l?- p°slc-
• • -J . -i . rior pala-
terior palatine hole : it is as large as the anterior tine hole,
palatine hole, but it serves a much more important
purpose; 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 palatine hole, and
then goes forward in two great branches along the
palate. Thus the chief nerves of the palate come
down to it through these posterior palatine 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 Hunter and Scarpa describe a nerve
from the fifth pair, taking its course in this way to
the soft palate.
The fourth foramen is formed by the union of the is-Lachry-
lower spongy bone to the internal nasal plate of the ma groovc-
bone; and is for the transmission of the lachrymal
duct: the groove will be observed just behind the
upright nasal process.
The LATERAL ORBITARY FISSURE, Called oftener 14. Lateral
spheno-maxillary fissure, has been already noticed:
it is a slit formed by this bone and the sphenoid bone ;
l 3
150
of the bones
it is a communication betwixt the orbit and temple ;
the deepest part is named spheno-palatine fissure.
The whole surface of the bone which forms the
antrum is perforated with frequent small holes, espe¬
cially 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 socket, and is for the accumulation of
fat, rather than for the transmission 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
Jar fora-60" body. At the termination of the alveolar circle,
mina. backwards, there are two or three holes, into which
the branches of the internal maxillary artery enter,
which go to supply the teeth of the upper jaw.
There is a trifling hole for the transmission of an
artery on the nasal plate of this bone.
The OSSA PALATI, or PALATE-BONES, are
very small, but have such a number of parts, and
such curious connections, as are not easily explained.
They seem to eke out the superior maxillary bones,
so as to lengthen the palate, and complete the nos¬
trils behind : they even extend upwards into the
socket, so as to form a part of its circle ; although,
in looking for them upon the entire skull, all these
parts are so hidden, that we should suppose the
palate-bones to be of no greater use nor extent than
to lengthen the palate a little backwards.
The parts of the palate-bone are these :
p,atcalatinc ^ie palatine plate, or process of the palate-
bone, whence it has its name, lies horizontal in the
same level with the palatine 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 each end ; in its being opposed to
its fellow by a broad surface, which completes the
9
of the face and jaws.
151
middle palatine suture ; and it is connected with
the palate process of the jaw by a suture resem¬
bling that by which the opposite bones are joined ;
but this suture, going across the back part of the
palate, is named the transverse palatine suture.
\V here 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 grind¬
ing 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 azygos uvulae, runs down in the
middle of the velum, taking its origin from this
middle part of the bones.
The small projecting point of the palate-bone, 2. Pte.y-
just behind the last grinding tooth, touches the f°s'sdp10"
pterygoid process of the sphenoid bone ; it is, there¬
fore, named the pterygoid process of the palate-
bone ; but it is so joined with the pterygoid process
of the sphenoidal bone, that they are not to be
distinguished 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 s. nasal
plate ; rises perpendicularly upwards from the palate; 1>late"
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-bone, that it lies
there like a sounding-board upon the side of the
antrum Highmorianum, and completes that cavity
forming the thin partition betwixt it and the nose.
On the inside of the nasal plate there is a rough pro- 4- Re¬
jection which runs horizontally, and is the continua¬
tion of a spine of the maxillary bone, for the attach¬
ment of the lower spongy bone. On the outside of 5- G™"ve
the nasal process is the groove for the palatine nerve.
l 4f
152
of the bones
6. Orbitary This nasal process extends thus up from the
plate and back Q£ the paiate 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
orbitary process ; or, as the knob has two faces
looking two ways in the orbit, it is divided some¬
times (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.
7. its ceil. 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.
The OSSA SPONGIOSA, or TURBINATA
INFERIORA, are so named, to distinguish them
from the upper spongy bones, which belong to the
os aethmoides ; but these lower spongy bones are
quite distinct, formed apart, and connected in a very
slight way with the upper jaw-bones.
The ossa spongiosa inferiora are two bones,
much rolled or convoluted, very spongy, much
resembling puff-paste, having exactly such holes,
cavities, and net-work, as we see in raised paste,
so that they are exceedingly light. They lie rolled
up, in the lower part of the nose; are particularly
large in sheep; are easily seen either in the entire
subject or in the naked skull. Their point forms that
projection which we touch with the finger in picking
the nose; and from that indecent practice, very
often serious consequences arise; for in many in¬
stances, polypi of the lower spongy bones, which
can be fairly traced to hurts of this kind, grow so
as to extend down the throat, causing suffocation
and death.
of the face and jaws.
153
One membrane constitutes the universal lining of
the cavities 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 dis¬
sected skull we find a neat small hook upon the
spongy bone, by which it is hung upon the edge of
the antrum maxillare; 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 aethmoid bone, in being less tur¬
binated 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 cri¬
briform plate of the aethmoid bone. We are indeed
not absolutely prohibited from pulling the polypi
from the upper spongy bone; but we are more at
ease in pulling them from the lower one, since it is
quite an insulated bone. When peas, or any such
foreign bodies, are detained in the nose, it must be
from swelling, and being detained among the spongy
bones.
The spongy bones are not absolutely limited in
their number: there is sometimes found betwixt
these two a third set of small turbinated bones, com¬
monly 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 slender bone, consisting
evidently of two plates, much compressed together, Plates,
very dense and strong, but still so thin as to be
154
of the bones
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.
United On its upper part, or, as we may call it, its base,
Shmoid. by which it is fixed to the skull, the vomer has a
wide groove, receiving the perpendicular plate of
The sphe- the aethmoid and sphenoid bones : thus it stands very
nmd. fjrm 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 of the
The palate- palate-plate, where the bones meet to form the
bone- palate-suture. At its fore part it is united by a
ragged 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
are all firmly connected, and covered by one con¬
tinuous membrane, which is thick and strong, and
that this is as a periosteum, 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 demonstrate with a very superfluous
1. upper accuracy. The upper orbitary process stands
process^' highest, running upwards to form part of the socket,
the outer corner of the eye, and the sharp edge of
2. inferior the temple. The inferior orbitary process, which
proee&Z is just opposite to this, forming the lower part of the
<3. Maxii- orbit, and the edge of the cheek. The maxillary
laryprocess. prqcess is that broad and rough surface, by which it
is joined to the upper jaw-bone. The one the best
entitled to the name of process, because it stands
of the face and jaws.
155
out quite insulated, and goes outwards and back¬
wards to unite with the temporal bone, forming the
zygoma or temporal arch, is named the zygomatic 4- zygoma-
process. That plate, which goes backwards to form tlc procLSS*
a part of the orbit, is named the internal orbitary 5. internal
process. A small hole is observed on the outer orr^srsy
surface of the bone, which transmits an artery, and 6.Foramen,
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 complication 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 re¬
served each for its proper place, while I explain the
form of the lower jaw, in the most simple and easy
way. The lower jaw is divided into the chin, viz.
the space betwixt the two mental foramina ; the
base, properly the sides, extending backward to the
angle ; and the upright portion of the bone.
The fore part, or chin, is in a handsome and manly chin,
face very square ; and this portion is marked out
by this squareness, 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, Base,
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 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 cannot
happen ; for in them the teeth have shorter roots,
and have no hold nor dangerous power over the
156
of the bones
jaw : though (as I have said) the sockets often suffer,
the jaw itself never yields.
Angle. 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. On the
upright branch, as it is termed, we see the impres¬
sions of the masseter muscle. This part, also, is easily
felt, and by it we judge well of the situation of veins,
arteries, and glands, which might be in danger of
being cut, in wounds or in operations. There are
two processes of the jaw of particular importance,
the coronoid or horn-like process, for the insertion
of its strong muscles, especially of the temporal
muscle, and the condyloid or hinge-process, by
which it is jointed with the temporal bone.
1. coronoid The coronoid process, named from its resem-
process. blance 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 defended by the
temporal arch, and so covered by muscles, that it
cannot be felt from without.
2. Condy- The condyloid process, or the articulating pro-
loidprocess. cegs q£. jaWj js 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, and has a lengthened
Cervix. neck. The condyle, or articulating 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, tkis joint is a mere hinge, not
admitting of lateral nor rotatory motions, at least of
OF THE FACE AND JAWS.
157
no wider lateral motions than those which are neces¬
sary in grinding the food; but the hinge of the jaw
is a complex and very curious one, which shall be
explained in its pioper place. The line of con- semi-lunar
tinuation between these two last processes forms notch>
what is called the semi-lunar notch.
The ALVEOLAR PROCESS, Or the long range of 3. Alveolar
sockets for the teeth, resembles that of the upper process-
jaw. The jaw, as the body grows, is slowly in¬
creasing in length, and the teeth are added in pro¬
portion to the growth of the jaws. When the jaws
have acquired their full size, the sockets are com¬
pletely 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 4. Spina
lower jaw, is just behind the symphysis, 01* on the interna-
inside of the circle of the chin. It gives origin to
muscles which move the tongue and larynx. On 5. Linea
the inside of the lateral portion of the jaw, we interna-
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 attachment
muscle. °^he o;d
The successive changes of the form of the jaw are 2°s!
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, Symphysis,
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 process; and another
set lies under them, ready to push them from the
jaws.
158
of the bones of the face, &c.
Secondly, That in youth the alveolar process is
extending, the teeth are increasing in number. The
coronoid and articulating processes are growing
acute and large, and are set off at right angles from
the bone. The teeth are now firmly rooted ; 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 sapientiae 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 process 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 con¬
veyed 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
coronoid process seems increased in length.
HOLES. — The holes of the jaw are chiefly
two:
7. internal A large hole on the inner side, and above the
maxillary angle of the jaw, just at the point where these two
branches, the condyloid 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
s. impres- forward to the tongue. And as nerves make an
nerves. 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
REVIEW OF THE SKELETON.
159
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 9. Mental
side of the chin, which permits the remains of the hole'
great nerve and artery (almost expended upon the
teeth) to come out upon the chin : it is named the
mental hole.
REVIEW OF THE SKELETON.
Although we are obliged to study the parts of
the human body separately, in what we choose to
call systems, as the bones, the muscles, the blood¬
vessels, yet these in nature form one system, and
have the most intimate correspondence. The bones
correspond witli the muscular parts ; and as the
strength of the muscular frame distinguishes the
male, so the male skeleton is marked by stronger
and heavier bones, where all the processes and
tubercles are more distinctly marked. It is for the
same reason that the skeleton of an athletic man is
valuable, because, corresponding with the fulness
and symmetry of the muscular frame, that activity
which has perfected the moving parts, has added
distinctness to all the points of demonstration of the
bones. It is a correspondence of the same kind
which accounts for the bones of a man suddenly cut
off in the vigour of health and exercise, being hard
as ivory, compared with the bones of one who has
lived an indolent life, or has long lain in sickness.
The skeleton of woman is further distinguished
from that of man : 1. By the depth of the vertebras ;
2. The narrowness of the lower part of the thorax ;
3. The sternum shorter, and more projecting; 4. The
diameters of the pelvis greater j the sacrum more
hollow, as well as broader; the os coccygis slender
and more flexible at its articulation ; 5. The aceta-
review of the skeleton.
bula more distant; 6. The thigh bones more oblique
in their position under the body ; 7* The feet small,
and the toes more pointed outward; 8. The bones of
the face smaller, and the cavities less developed.
To these some add a peculiarity in the sagittal
sutures, since the lateral divisions of the os frontis are
joined later than in man.
As to the height of the human skeleton, we have,
in the collections in London, skeletons of the na¬
tural form, varying from eight feet two inches to
thirty-five inches in height. However we may ac¬
count for the giant height, that of the dwarf is
undoubtedly from disease, a diseased limitation of the
growth of the whole body, which we sometimes see
in individual parts of the body.
In reviewing the general form of the skeleton, we
are naturally called to observe the spine.
When we contemplate the mechanism of the skull,
we shall find that for protecting the brain its form is
perfect, secure on all sides, and strengthened where
the exposure to injury is the greatest. The spinal
column, which sustains the skull, has equal provisions
for the security of the brain; and, what is most
admirable, there is an entirely different principle
introduced here ; for whereas in the head, the whole
aim is firmness in the joinings of the bones, in the
spine which supports the head, the object to be at¬
tained is mobility or pliancy. In the head, each
bone is firmly secured to another; in the spine the
bones are not permitted to touch : there is interposed
a soft and elastic material, which takes off the jar
that would result from the contact of the bones. We
shall consider this subject a little more in detail.
The spinal column, as it is called, serves three
purposes : it is the great bond of union betwixt all
the parts of the skeleton; it forms a tube for the
lodgment of the spinal marrow, a part of the nervous
system as important to life as the brain itself; and
lastly, it is a column to sustain the head.
We now see the importance of the spine, and we
REVIEW OF THE SKELETON.
shall explain how the various offices are provided
for.
If the protection of the spinal marrow had been
the only object of this structure, it is natural to infer
that it would have been a strong and unyielding tube
of bone ; but, as it must yield to the inflexions of
the body, it cannot be constituted in so strict an
analogy with the skull. It must, therefore, bend ;
but it must have no abrupt or considerable bending
at one part; for the spinal marrow within would in
this way suffer.
By this consideration we perceive why there are
twenty-four bones in the spine, each bending a little ;
each articulated or making a joint with its fellow ;
all yielding in a slight degree, and, consequently,
permitting in the whole spine that flexibility neces¬
sary to the motions of the body. It is next to be
observed that, whilst the spine by this provision
moves in every direction, it gains a property which
belongs more to our present purpose to understand.
At each interstice between the vertebras there is a
peculiar elastic gristly substance, which is squeezed
out from betwixt the bones, and permits them
to approach and play a little in the motions of the
body. This gristly substance is enclosed in an elastic
binding, or membrane of great strength, which
passes from the edge or border of one vertebra to
the border of the one next it. When a weight is
upon the body, the soft gristle is pressed out, and
the membrane yields : the moment the weight is
removed, the membranes recoil by their elasticity,
the gristle is pressed into its place, and the bones
resume their position.
We can readily understand how great the influence
of these twenty-four joinings must be in giving elas¬
ticity to the whole column ; and how much this must
tend to the protection of the brain. Were it not for
this interposition of elastic material, every motion
of the body would produce a jar to the delicate tex¬
ture of the brain, and we should suffer almost as
much in alighting on our feet as in falling on our
VOL. i. M
REVIEW OF THE SKELETON.
head. It is, on tlie same principle, necessary for the
builder to interpose thin plates of lead or slate be¬
tween the different pieces of a column to prevent the
edges (technically called arrises) of the cylinders
from coming in contact, as they would, in that case,
chip or split off.
But there is another very curious provision for the
protection of the brain : we mean the curved form
of the spine. If a steel spring, perfectly straight, be
pressed betwixt the hands from its extremities, it
will resist, notwithstanding its elasticity, and when
it does give way, it will be with a jerk. Such would
be the effect on the spine if it stood upright, one
bone perpendicular to another ; for then the weight
would bear equally ; the spine would yield neither
to one side nor to the other; and, consequently,
there wrould be a resistance from the pressure on
all sides being balanced. We, therefore, see the
great advantage resulting from the human spine
being in the form of an italic f. It is prepared to
yield in the direction of its curves ; the pressure
is of necessity more upon one side of the column
than on the other; and its elasticity is immediately
in operation without a jerk. It yields, recoils, and
so forms the most perfect spring; admirably calcu¬
lated to carry the head without jar, or injury of any
kind. The most unhappy illustration of all this is
the condition of old age. The tables of the skull are
then consolidated, and the spine is rigid: if an old
man should fall with his head upon the carpet, the
blow, which would be of no consequence to the
elastic frame of a child, may to him prove fatal; and
the rigidity of the spine makes every step which he
takes vibrate to the interior of the head, and jar on
the brain.
We may observe, that the spine of an infant is
not so pyramidal as in the adult. It is some time
before the vertebrae of the loins assume their just
form. The spine of the infant is straight, compared
to the column of the adult: by which we see that
there is a growth, and gradual change in the con-
6
review of the skeleton".
formation of the chain of bones, fitting them for the
erect posture.
In the adult the direction of the lumbar vertebrae,
forward from the sacrum, protects the spine in the
motion of the body; for if the spine stood perpen¬
dicularly, its base would be jarred in advancing for¬
wards. We may take the comparison betwixt the
attachment of the spine to the pelvis, and the in¬
sertion of the mast of a ship into the hull. The
mast goes directly through the decks without touch¬
ing them, and the heel of the mast goes into the step,
which is formed of large solid pieces of oak timber
laid across the keelson. The keelson is an inner
keel, resting upon the floor-timbers of the ship, and
directly over the proper keel. These are contriv¬
ances for enlarging the base, on which the mast
rests as a column : for, in proportion to the height
and weight of a column, its base must be enlarged,
or it would sink into the earth; and so, if the mast
were to bear upon a point, it would break through
the bottom of the ship.
The mast is supported upright by the shrouds and
stays. The shrouds secure it against the lateral or
rolling motion, and the stays and backstays against
the pitching of the ship. These form what is termed
the standing rigging. The mast does not bear upon
the deck, or on the beams of the ship ; indeed there
is a space covered with canvas, betwixt the deck and
the mast.
We often hear of a new ship going to sea to stretch
her riggings that is, to permit the shrouds and stays
to be stretched by the motion of the ship, after which
they are again braced tight: for if she were over¬
taken by a storm before this operation, and when the
stays and shrouds were relaxed, the mast would lean
against the upper deck, by which it would be sprung
or carried away. Indeed, the greater proportion of
masts that are lost, are lost in this manner. There
are no boats which keep the sea in storms like
those which navigate the gulf of Finland; their
masts are not attached at all to the hull of the ship,
but simply rest upon the step.
m 2
164-
REVIEW OF THE SKELETON.
Although the spine has not a strict resemblance to
the mast, the contrivances of the ship-builder, how¬
ever different from the provisions of nature, show
what is the object to be attained; and when we are
thus made aware of what is necessary to the security
of a column on a moveable base, we are prepared to
appreciate the superior provisions of nature for
giving security to the human spine.
The human spine rests on the pelvis, or basin; a
circle of bones, of which the haunches are the ex¬
treme lateral parts ; and the sacrum (which is as the
keystone of the arch) is the central part. To this
central bone of the arch of the pelvis the spine is
connected; and, taking the similitude of the mast,
the sacrum is as the step on which the base of the
pillar, like the heel of the mast, is socketed or mor¬
tised. The spine is tied to the lateral parts of the
pelvis by powerful ligaments, which may be com¬
pared to the shrouds. They secure the lower part
of the spine against the shock of lateral motion or
rolling; but, instead of the stays to limit the play of
the spine forwards and backwards in pitching, or
to adjust the rake of the mast, there is a very beau¬
tiful contrivance in the lower part of the column.
The spine forms here a semicircle, which has this
effect; that, whether by the exertion of the lower
extremities the spine is to be carried forward upon
the pelvis, or whether the body stops suddenly in
running, the jar which would necessarily take place
at the lower part of the spine, C.* if it stood upright
like a mast, is distributed over several of the bones
of the spine ; and, therefore, the chance of injury at
any particular part is diminished.
For example, the sacrum, or centre bone of the
pelvis, being carried forward, as when one is about
to run, the force is communicated to the lowest bone
of the spine. But, then, the surfaces of these bones
stand with a very slight degree of obliquity to the
line of motion; the shock communicated from the
lower to the second bone of the vertebrae is still in
a direction very nearly perpendicular to its surface
* See the woodcut, p. 166.
REVIEW OF THE SKELETON.
of contact. The same takes place in the communi¬
cation of force from the second to the third, and
from the third to the fourth; so that before the
shock of the horizontal motion acts upon the perpen¬
dicular spine, it is distributed over four bones of that
column, instead of the whole force being concen¬
trated upon the joining of any two, as at C.
It the column stood upright, it would be jarred at
the lowest point of contact with its base. But by
forming a semicircle, the motion, which would pro¬
duce a jar on the very lowest part of the column,
is distributed over a considerable portion of the
column; and in point of fact, this part of the spine
never gives way.
In reviewing the building up of the column, there
are three points which possess more extensive motion,
and which, on that very account, are more subject to
accident and to disease. The first is near the junction
of the vertebrae of the back to those of the loins ;
for as the vertebrae of the back constitute the most
unyielding part of the chain, where they terminate
below, the flexibility of the adjoining piece must be
the greater, and proportionally weaker—a fishing-
rod breaks close to the joining, because the part
joined is inflexible.
As some introduction to the study of the defor¬
mities of this column, we may observe the necessary
consequence of growth and stature. We cannot fail
to observe, that a little fat man carries himself per¬
pendicularly, throwing the body backward, as it
were, briskly, for which he is accused of conceit;
when it is no more than balancing the anterior
weight of his belly, by throwing back the trunk and
shoulders. And so the incessns of a pregnant woman
is stately, and she is accused of carrying her burden
proudly, when, it may be, there is more shame than
pride ; yet she must throw the body back, to poise
the increased weight of her condition. It is upon
the same principle, that parents have so much trouble
with a tall and thin young person, who naturally
stoops, since the spine and head are always brought
ivr 3
166
review of the skeleton.
to bear perpendicularly over the sacrum ; and the
want of filling up, and consequent comparative defi¬
ciency of weight in front, makes the head and shoul¬
ders project forward. The spine, being a flexible
column, produces that consent through the whole
body, to which the eye is familiar, without our seek¬
ing to account for it. The stiff knee, and the erect
position of the head, correspond, just as the relaxed
knees, and the pelvis projecting backwards in old
age, is accompanied with the curve in the back and
the stoop of the neck and shoulders. These natural
consequences should be well considered by those who
append weights to young people to correct their car¬
riage, when they should be attending to the conforma¬
tion and the natural exercise of the trunk and limbs.
It has been explained how the pelvis stands, as
an arch betwixt the spine and the lower extremities.
From the term pelvis, and from the manner in which
the student has these collected bones demonstrated
to him, he is apt to forget how they stand in relation
to the body. If a line were drawn perpendicularly
review of the skeleton.
from the centre of the brim of the pelvis, that line
would come through the umbilicus. If that line
were carried through the cavity of the pelvis, equi¬
distant from the sacrum and pubis in all its course,
it would form a curve D E; and this curved line,
passing through the pelvis, is properly the axis of the
pelvis. It is the line in which the child's head de¬
scends ; it is the line in which instruments are used :
the forceps in midwifery, the gorget in lithotomy ;
the trocar in puncturing the bladder must also be
used with due regard to this line.
And now that the bones are contemplated in their
natural relation, we see into what form the pelvis will
be distorted, by the combined influence of rickets,
pressure, and the progress of growth in the bones.
The arch receives the pressure in three points ; on
the acetabula, where they rest on the thigh-bones,
and on the sacrum, which, like the key-stone of an
arch, closes the bones of the pelvis, and supports the
column of the spine and the incumbent weight of the
body. The consequence of this is, that the distorted
pelvis assumes, most frequently, a triangular form.
Sometimes, however, the ossa pubis are pressed in so
uniformly as to give the pelvis a flattened form ; and
the accoucheur would do well to consider the form
of the distorted pelvis, before he gives out his abso¬
lute rule, regarding what is to be done in certain
degrees of diminished diameter in the brim and outlet
of the pelvis.
of the chest.
In extending the parallel between the structure of
the body and the works of human art, it signifies
very little to what part we turn; for the happy
adaptation of means to the end will every where
call for our admiration, in exact proportion to our
success in comprehending the provisions which
Supreme Wisdom has made. ^ e turn now to a
short view of the bones of the chest.
The thorax, or chest, is composed of bones and
m 4
REVIEW OF THE SKELETON.
cartilages, so disposed as to sustain and protect the
most vital parts, the heart and lungs, and to turn
and twist with perfect facility in every motion of the
body : and to be in incessant motion in the act of
respiration, without a moment's interval during a
whole life. In anatomical description, the thorax
is formed of the vertebral column or spine, on the
back part, the ribs on either side, and the breast¬
bone or sternum, on the fore part. But the thing
most to be admired is the manner in which these
bones are united, and especially the manner in which
the ribs are joined to the breast-bone, by the interpo¬
sition of cartilages, or gristle, — of a substance softer
than bone, and more elastic and yielding. By this
quality they are fitted for protecting the chest against
the effects of violence, and even for sustaining life
after the muscular power of respiration has become
too feeble to continue without this support.
If the ribs were complete circles, formed of bone,
and extending from the spine to the breast-bone,
life would be endangered by any accidental blow;
even the rubs and jolts to which the human frame
is continually exposed, would be too much for their
delicate and brittle texture. But these evils are
avoided by the interposition of the elastic cartilage.
On their fore part the ribs are eked out, and joined
to the breast-bone by means of cartilages, of a form
corresponding to that of the ribs, being, as it were,
a completion of the arch of the rib, by a' substance
more adapted to yield in every shock or motion
of the body. The elasticity of this portion subdues
those shocks which would occasion the breaking of
the ribs. We lean forward, or to one side, and the
ribs accommodate themselves, not by a change of
form in the bones, but by the bending or elasticity
of the cartilages. A severe blow upon the ribs does
not break them, because their extremities recoil and
yield to the violence. It is only in youth, however,
when the human frame is in perfection, that this
pliancy and elasticity have full effect. When old age
approaches, the cartilages of the ribs become bony.
REVIEW OF THE SKELETON.
They attach themselves firmly to the breast-bone,
and the extremities of the ribs are fixed, as if the
whole arch were formed of bone unyielding and in¬
elastic. Then every violent blow upon the side is
attended with fracture of the rib, an accident seldom
occurring in childhood, or in youth.
But there is a purpose still more important to be
accomplished by means of the elastic structure of
the ribs. This is in the action of breathing, especially
in the more highly-raised respiration which is neces¬
sary in great exertions of bodily strength, and in
violent exercise. There are two acts of breathing—
expiration, or the sending forth of the breath ; and
inspiration, or the drawing in of the breath. When
the chest is at rest, it is neither in the state of
expiration nor in that of inspiration ; it is in an
intermediate condition between these two acts. And
the muscular effort by which either inspiration or
expiration is produced, is an act in opposition to the
elastic property of the ribs. It is the property of the
ribs to preserve the breast in that intermediate state
between expiration and inspiration. The muscles
of respiration are excited alternately, to dilate or to
contract the cavity of the chest, and, in doing so, to
raise or to depress the ribs. Hence it is, that both
in inspiration and in expiration the elasticity of the
ribs is called into play; and, were it now within our
province, it would be easy to show, that this pro¬
perty of the cartilages of the ribs preserves life, by
respiration being continued after the vital muscular
power, without such assistance, was too weak to
carry it on.
It will at once be understood, from what has now
been explained, how, in age, violent exertion is
under restraint, in so far as it depends on respi¬
ration. The elasticity of the cartilages is gone,
the circle of the ribs is now unyielding, and will
not allow that high breathing, that sudden and
great dilatation and contraction of the cavity of the
chest, which is required for circulating the blood
through the lungs, and relieving the heart amidst the
REVIEW OF THE SKELETON.
more tumultuous flowing of the blood which exercise
produces.
The thorax of the human skeleton is remarkable
for its transverse diameter, its elevation and short¬
ness*, and, consequently, for the large space betwixt
the pelvis and margin of the chest, which gives a
remarkable facility and extent to the motion of the
human body. Quadrupeds have the thorax com¬
pressed laterally, with a projecting and lengthened
sternum, so that the scapulae rest on the sides of the
thorax, and the fore legs stand perpendicularly
under the chest.
OF THE EXTREMITIES.
There are a class of philosophers who conjoin, as
necessary parts of the same plan, man's reason and
the perfection of the hand, the one for council, the
other for action. The peculiarity of the upper ex¬
tremity, as distinguishing it from the lower extremity,
is the smallness of the bones, the freedom of their
articulations, and the great variety of motions attain¬
able through the combination of the whole. As
distinguished from the anterior extremity of brutes,
we find its peculiarity principally in the perfect cla¬
vicle, in the great mobility of the scapula, and the
lateral projection of the glenoid cavity ; in the pro¬
vision of the joint of the elbow for the co-operation
of the hands, and in the perfect articulation of the
twenty-nine bones of the carpus, metacarpus, and
fingers ; in the position of the bones, and in the
strength of the muscles of the thumb. There is a
sort of resemblance in the arrangement of the bones
of the lower and upper extremities : but the solid
junction of the bones of the leg, the firm building of
the bones of the tarsus, and the strength and size
and firmly wedged position of the metatarsal of the
great toe, are in remarkable contrast with the free
* The horse has thirty-six ribs ; there are thirty-two in the
hyena ; forty in the elephant.
REVIEW OF THE SKELETON.
rotatory motions of the radius, and the mobility of
the thumb, and the freedom and extent of motion
of the fingers.
The size and strength of the lower extremities at
once declare the provision of the human skeleton
for the upright position, and that there is no true
biped but man. The admirable adaptation of all
creatures to their condition, and the provision of
monkeys and apes to climb and spring among the
branches of trees, has given rise to' long and useless
speculations, not very creditable to philosophy.
These creatures are of the class quadrumanus; their
hind feet are as perfect instruments of prehension as
their paws, which shows the limited object of their
structure. A silly observation is copied through
many books, that we owe the position of the toe to
the dancing-master ; but every thing in the shape of
the bones of the lower extremity, and the insertion
of the muscles, conform to this object; and it is
that which gives elasticity, freedom, and, conse¬
quently, elegance to the motion of the body. How
awkward is that man's gait who walks directly over
his toes ; and if a woman have one foot placed
straight forward and the other pointed, you perceive
the effect in the awkward motion of the whole of
one side of the body compared with the other.
There are, in all, thirty-six bones in the foot ;
and the first question that naturally arises, is, Why
should there be so many bones ? The answer is, In
order that there may be so many joints; for the
structure of a joint not only permits motion, but
bestows elasticity.
A joint consists of the union of two bones, of
such a form as to permit the necessary motion ; but
they are not themselves in contact: each articulating
surface is covered with cartilage, to prevent the jar
which would result from th£ contact of the bones.
This cartilage is elastic, and the celebrated Dr. Hunter
discovered that the elasticity was in consequence of
the numberless filaments being closely compacted,
and extending from the surface of the bone, in such
REVIEW OF THE SKELETON.
a manner that every filament was perpendicular to
the pressure made upon it. The surface of the
articulating cartilage is perfectly smooth, and is
lubricated by the fluid called synovia, a viscous or
oily liquor. A delicate membrane extends from
bone to bone, confining this lubricating fluid, and
forming the boundary of what is termed the cavity
of the joint, although, in fact, there is no un¬
occupied space. External to this capsule of the
joint, there are strong ligaments going from point
to point of the bones, and so ordered as to bind
them together without preventing their proper mo¬
tions. From this description of a single joint, we
can easily conceive what a spring or elasticity is
given to the foot, where thirty-six bones are jointed
together.
The most obvious proof of contrivance is the
junction of the foot to the bones of the leg at the
ankle joint. The two bones of the leg, the tibia and
theJibula, receive the great articulating bone of the
foot (the astragalus) betwixt them. And the extre¬
mities of these bones of the leg project so as to form
the outer and inner ankle. Now, when we step for¬
ward, and whilst the foot is raised, it rolls easily
upon the ends of these bones, so that the toe may
be directed according to the inequalities of the
ground we are to tread upon ; but when the foot is
planted, and the body is carried forward perpendicu¬
larly over the foot, the joint of the leg and foot
becomes fixed, and we have a steady base to rest
upon. Notwithstanding this mobility of the foot in
some positions, when the weight of the body bears
directly over it, it becomes so immoveable that the
bones of the leg must be fractured before it yields.
We next observe, that, in walking, the heel first
touches the ground. If the bones of the leg were
perpendicular over the part which first. touches the
ground, we should come down with a sudden jolt,
instead of which we descend in a semicircle, the
centre of which is the point of the heel. And when
the toes have come to the ground we are far from
REVIEW OF THE SKELETON.
losing the advantages of the structure of the foot,
since we stand upon an elastic arch, the hinder
extremity of which is the heel, and the anterior the
balls of the toes. A finely formed foot should be
high in the instep. The walk of opera dancers is
neither natural nor beautiful; but the surprising
exercises which they perform give to the joints of
the foot a freedom of motion almost like that of the
hand. We have seen the dancers, in their morning
exercises, stand for twenty minutes on the extremities
of their toes; after which the effort is made to bend the
inner ankle down to the floor, in preparation for the
Bolero step. By such unnatural postures and exer¬
cises the foot is made unfit for walking, as may be
observed in any of the retired dancers and old
figurantes. By standing so much upon the toes, the
human foot is converted to something more resem¬
bling that of a quadruped, where the heel never
reaches the ground, and where the paw is nothing
more than the phalanges of the toes.
This arch of the foot, from the heel to the toe,
has the astragalus resembling the keystone of an
arch ; but, instead of being fixed, as in masonry,
it plays freely betwixt two bones, and from these two
bones, the os calcis and os naviculare, a strong
elastic ligament is extended, on which it rests, sink¬
ing or rising as the weight of the body bears upon it,
or is taken off, and this it is enabled to do by the
action of the ligament which runs under it.
This is the same elastic ligament which runs ex¬
tensively along the back of the horse's hind leg and
foot, and gives the fine spring to it, but which is
sometimes ruptured by the exertion of the animal
in a leap, producing irrecoverable lameness.
Having understood that the arch of the foot is
perfect from the heel to the toe, we have next to
observe, that there is an arch from side to side; for
when a transverse section is made of the bones of the
foot, the exposed surface presents a perfect arch of
wedges, regularly formed like the stones of an arch
in masonry. If we look down upon the bones of the
REVIEW OF THE SKELETON.
foot, we shall see that they form a complete circle
horizontally, leaving a space in their centre. These
bones thus form three different arches — forward ;
across ; and horizontally : they are wedged together,
and bound by ligaments. And this is what we
alluded to when we said that the foundations of the
Eddystone lighthouse were not laid on a better prin¬
ciple ; but our admiration is more excited in ob¬
serving, that the bones of the foot are not only
wedged together, like the courses of stone, for resist¬
ance, but that solidity is combined with elasticity
and lightness.
How much system there is in every thing belong¬
ing to an animal body, and what relation there is
established through the whole skeleton, we may
learn from the following considerations.
What we have now to state has been the result of
the studies of many naturalists ; of men who have
laboured in the department of comparative anatomy,
but have failed to seize upon it with the privilege of
genius, and to handle it in the masterly manner of
Cuvier.
Suppose a man ignorant of anatomy picks up a
bone in an unexplored country, he learns nothing,
except that some animal has lived and died there;
but the anatomist can, by that single bone, estimate,
not merely the size of the animal, as well as if he
saw the print of its foot, but the form and joints of
the skeleton, the structure of its jaws and teeth, the
nature of its food, and its internal economy. This,
to one ignorant of the subject, must appear wonder¬
ful, but it is after this manner that the anatomist
proceeds : let us suppose that he has taken up that
portion of bone in the limb of the quadruped which
corresponds to the human wrist; and that he finds
that the form of the bone does not admit of free
motion in various directions, like the paw of the
carnivorous creature. It is obvious, by the structure
of the part, that the limb must have been merely for
supporting the animal, and for progression, and not
for seizing prey. This leads him to the fact that
REVIEW OF THE SKELETON.
there were no. bones resembling those of the hand
and fingers, or those of the claws of the tiger ; for the
motions which that conformation of bones permits
in the paw would be useless without the rotation
of the wrist — he concludes that these bones were
formed in one mass, like the cannon-bone, pastern-
bone, and coffin-bones of the horse's foot. *
The motion limited to flexion and extension of
the foot of a hoofed animal implies a restrained mo¬
tion in the shoulder joint; and thus the naturalist,
from the specimen in his hand, obtains a very perfect
notion of all the bones of the anterior extremity!
The motions of the extremities imply a condition of
the spine which unites them. Each bone of the spine
will have that form which permits the bounding of
the stag, or the galloping of the horse, but it will
not have that form of joining which admits the turn¬
ing or writhing of the spine, as in the leopard or
the tiger.
And now he comes to the head : — the teeth of a
carnivorous animal, he says, would be useless to
rend prey, unless there were claws to hold it, and a
mobility of the extremities like the hand, to grasp it.
He considers, therefore, that the teeth must have been
for bruising herbs, and the back teeth for grinding.
The socketing of these teeth in the jaw gives a pecu¬
liar form to these bones, and the muscles which move
them are also peculiar ; in short, he forms a concep¬
tion of the shape of the skull. From this point he
may set out anew, for by the form of the teeth, he
ascertains the nature of the stomach, the length of
the intestines, and all the peculiarities which mark
a vegetable feeder.
Thus the whole parts of the animal system are so
connected with one another, that from one single
bone or fragment of bone, be it of the jaw, or of the
* For these are solid bones, where it is difficult to recognise
any resemblance to the carpus, metacarpus and bones of* the
fingers ; and yet comparative anatomy proves that these moveable
bones are of the same class with those in the solid hoof of the
belliue of Linnaeus.
review of the bones of the cranium.
spine, or of the extremity, a really accurate concep¬
tion of the shape, motions, and habits of the animal,
may be formed.
It will readily be understood that the same process
of reasoning will ascertain, from a small portion of a
skeleton, the existence of a carnivorous animal, or of
a fowl, or of a bat, or of a lizard, or of a fish ; and
what a conviction is here brought home to us, of the
extent of that plan which adapts the members of
every creature to its proper office, and yet exhibits
a system extending through the whole range of ani¬
mated beings, whose motions are conducted by the
operation of muscles and bones !
After all, this is but a part of the wonders dis¬
closed through the knowledge of a thing so despised
as a fragment of bone. It carries us into another
science; since the knowledge of the skeleton not
only teaches us the classification of creatures, now
alive, but affords proofs of the former existence
of animated beings which are not now to be found
on the surface of the earth. We are thus led to
an unexpected conclusion from such premises ; not
merely the existence of an individual animal, or race
of animals, but even the changes which the globe
itself has undergone in times before all existing
records, and before the creation of human beings to
inhabit the earth, are opened to our contemplation.
REVIEW OF THE BONES OF THE
CRANIUM, &c.
It requires no disquisition to prove that the brain
is the most essential organ of the animal system, and
being so, we may presume that it must be especially
protected. We are now to inquire how this main
object is attained?
We must first understand that the brain may be
hurt, not only by sharp bodies touching and entering
it, but by a blow upon the head which shall vibrate
through it, without the instrument piercing the skull.
REVIEW OF THE BONES OF THE CRANIUM.
Indeed, a blow upon a man's head, by a body which
shall cause a vibration through the substance of the
brain, may more effectually deprive him of sense
and motion than if an axe or a sword penetrated
into the substance of the brain itself.
Supposing that a man's ingenuity were to be ex¬
ercised in contriving a protection to the brain, he
must perceive that if the case were soft, it would be
too easily pierced ; that if it were of a glassy nature,
it would be chipped and cracked; that if it were of
a substance like metal, it would ring and vibrate,
and communicate the concussion to the brain.
Further thoughts might suggest, that whilst the
case should be made firm to resist a sharp point, the
vibrations of that circular case might be prevented
by lining it with a softer material ; just as no bell
can vibrate having such an incumbrance ; its sound
is stopped like the ringing of a glass by the touch
of a finger.
If a soldier's head be covered with a steel cap, the
blow of a sword which does not penetrate will yet
bring him to the ground by the percussion which
extends to the brain ; therefore, the helmet is lined
with leather, and covered with hair ; for, although
the hair is made an ornament, it is an essential part
of the protection : we may see it in the head-piece
of the Roman soldier, where all useless ornament,
being despised as frivolous, was avoided as cumbrous.
We now perceive why the skull consists of two
plates of bone, one external, which is fibrous and
tough, and one internal, dense to such a degree that
the anatomist calls it tabula vitrea (the glassy table.)
Nobody can suppose this to be accidental. It has
just been stated, that the brain may be injured in
two ways : a stone or a hammer may break the skull,
and the depressed part of the bone injure the brain ;
whilst, on the other hand, a mallet struck upon the
head will, without penetrating, effectually deprive
the brain of its functions, by causing a vibration
which runs round the skull and extends to every
portion of its contents.
VOL. i. N
REVIEW OF THE BONES OF THE CRANIUM.
Were the skull, in its perfect or mature state,
softer than it is, it would be like the skull of a child;
were it harder than we find it is, it would be like that
of an old man. In other words, as in the former it
would be too easily pierced, so, in the latter, it would
vibrate too sharply and produce concussion. The
skull of an infant is a single layer of elastic bone ; on
the approach to manhood it separates into two tables ;
and in old age it again becomes consolidated. During
the active years of man's life the skull is perfect: it
then consists of two layers, united by a softer sub¬
stance ; the inner layer is brittle as glass, and cal¬
culated to resist any thing penetrating; the outer
table is tough, to give consistence, and to stifle the
vibration which would take place if the whole texture
were uniform and like the inner table.
The distinction in the tables of the skull is of the
utmost consequence to the surgeon : it explains what
takes place in fracture of the skull, and affords him
the principles upon which he performs the operation
of trepan. Where a portion of the skull is driven
in, owing to the greater brittleness of the inner table,
the internal part is broken off to a greater extent than
the outer. Thus it happens that the diameter of the
inner table of the broken portion is greater than the
diameter of the outer table : and the inner margin
of the detached portion of bone shelves under the
margin of the hole in the skull. It is necessary,
therefore, that the hole in the skull should be enlarged,
to bring out the detached portion of bone. From
the same peculiarity of the two layers in the skull,
the inner table of bone will be fractured when there
is hardly any injury apparent on the outer table.
The alteration in the substance of the bones, and
more particularly in the skull, is marvellously ordered
to follow the changes in the mind of the creature,
from the heedlessness of childhood to the caution
of age, and even the helplessness of superannuation.
The skull is soft and yielding at birth ; during child¬
hood it is elastic, and little liable to injury from con¬
cussion ; and during youth, and up to the period of
13
REVIEW OF THE BONES OF THE CRANIUM.
maturity, the parts which come in contact with the
ground are thicker, whilst the shock is dispersed
towards the sutures which are still loose. But when,
with advancing years, something tells us to give up
feats of activity, and falls are less frequent, the bones
lose that nature which would render concussion
harmless, and at length the timidity of age teaches
man that his structure is no longer adapted to active
life.
We must understand the necessity of the double
layer of the skull, in order to comprehend another
very curious contrivance. The sutures are the lines
of union of the several bones which form the cra¬
nium, and surround and protect the brain. These
lines of union are called sutures (from the Latin
word for sewing), because they resemble seams. If
a workman were to inspect the joining of two of the
bones of the cranium, he would admire the minute
dove-tailing by which one portion of the bone is
inserted into, and surrounded by, the other, whilst
that other pushes its processes or juttings out between
those of the first in the same manner, and the fibres
of the two bones are thus interlaced, as you might
interlace your fingers. But when you look to the
internal surface, you see nothing of this kind ; the
bones are here laid simply in contact, and this line
is called harmonici, or harmony: architects use the
same term to imply the joining by masonry. Whilst
the anatomists are thus curious in names, it is
provoking to find them negligent of things more
interesting. Having overlooked the reason of the
difference in the tables of bone, they are conse¬
quently blind to the purpose of this difference of
the outward and inward part of a suture.
Suppose a carpenter employed upon his own ma¬
terial, he would join a box with minute and regular
indentations by dovetailing, because he knows that
the material on which he works, from its softness
and toughness, admits of such adjustment of its edges.
The processes of the bone shoot into the opposite
cavity with an exact resemblance to the foxtail wedge
180
REVIEW OF THE BONES OF THE CRANIUM.
of the carpenter — a kind of tenon and mortice when
the pieces are small.
But if a workman in glass or marble were to inclose
some precious thing, he would smooth the surfaces
and unite them by cement, because, even if he could
succeed in indenting the line of union, he knows
that his material would chip off on the slightest
vibration. The edges of the marble cylinders which
form a column are, for the same reason, not per¬
mitted to come in contact; thin plates of lead are
interposed to prevent the edges, technically termed
arrises, from chipping off or splitting.
Now apply this principle to the skull. The outer
softer tough table, which is like wood, is indented
and dovetailed ; the inner glassy table has its edges
simply laid in contact. It is mortifying to see a
course of bad reasoning obscure this beautiful subject.
They say that the bone growing from its centre, and
diverging, shoots its fibres betwixt those which come
in an opposite direction ; thus making one of the
most curious provisions of nature a thing of accident.
Is it not enough to ask such reasoners, why there is
not a suture on the inside as well as on the out?
The junction of the bones of the head generally
being thus exact, and like the most finished piece of
cabinet work, let us next enquire, whether there be
design or contrivance shown in the manner in which
each bone is placed upon another.
When we look upon the side of the skull thus,
the temporal suture betwixt the bones A and D is
formed in a peculiar manner ; the lower or temporal
bone laps over the superior or parietal bone. This,
A. The parietal bono.
B. The frontal bone.
C. The occipital bone.
D. The temporal bone.
E. The sphenoid bone.
review of the bones of the cranium.
too, has been misunderstood : that is to say, the
plan of the building of the bones of the head has
not been considered; and this joining, called the
squamous suture, which is a species of scarfing, has
been supposed a mere consequence of the pressure
of the muscle which moves the jaw. Dr. Monro says,
" the manner how I imagine this sort of suture is
formed at these places, is, that by the action of the
strong temporal muscles on one side, and by the
pressure of the brain on the other, the bones are
made so thin that they have not large enough sur¬
faces opposed to each other to stop the extension of
their fibres in length, and thus to cause the common
serrated appearance of sutures ; but the narrow edge
of the one bone slides over the other."
The very name of the bones might suggest a
better explanation. The ossa parietalia, the two
large bones of a regular square shape, serve as
walls to the interior or room of the head, where the
brain is lodged. Did the reader ever notice how
the walls of a house are assisted when thin and over¬
burdened with a roof?
The wall plate is a portion of timber built into the
wall, to which a transverse or tie-beam is attached
by carpentry. This cogging, as it is termed, keeps
the wall in the perpendicular, and prevents any lateral
pressure of the roof. We sometimes see a more
clumsy contrivance, a clasp, or a round plate of iron,
upon the side of a wall ; this has a screw going into
the ends of a cross-beam, and by embracing a large
portion of the brick-work, it holds the wall from
shifting at this point. Or take the instance of a roof
supported on inclined rafters, A B : —
Were they thus, with¬
out further security,
placed upon the walls,
the weight would tend
to spur or press out the
walls, whicli must be
strong and heavy to support the roof; therefoie, the
skeleton of the roof is made into a truss, (for so the
whole joined carpentry is called.) The upper cross-
n 3
REVIEW OF THE BONES OF THE CRANIUM.
beam marked by the dotted lines C, is a collar-beam,
connecting the rafters of the roof, and stiffening them,
and making the weight bear perpendicularly upon
the walls. When the transverse beam joins the
extremities of the rafters, as indicated by the lower
outline D, it is called a tie-beam, and is more power¬
ful still in preventing the rafters from pushing out
the walls.
Now when a man bears a burden upon his head,
the pressure, or horizontal push, comes upon the
lower part of the parietal bones, and if they had not
a tie-beam, they would, in fact, be spurred out, and
the bones of the head be crushed down. But the
temporal bone D, and still more, the sphenoid bone
E, by running across the base of the skull, and having
their edges lapping over the lower part of the great
walls, or the parietal bones, lock them in as if they
had iron plates, and answer the purpose of the
tie-beam in the roof, or the iron plate in the walls.
But the connexion is at the same time so secure,
that these bones act equally as a straining piece, that
is, as a piece of timber, preventing the tendency of
the sides of the skull to each other.
It may be said, that the skull is not so much like
the wall of a house as like the arch of a bridge : let
us then consider it in this light.
We have here the two parietal bones, separated
and resting against each other, so as to form an
arch. In the centering, which is the wooden
frame for supporting a stone arch while building,
there are some principles that are applicable to the"
head.
B
the centre of each bone,
J the bone is more convex,
Ijjij and thicker at this part.
We see that the arch
formed by the two pa¬
rietal bones is not a
perfect semi-circle;
there is a projection at
The cause assigned for
this is, that it is the
REVIEW OF THE BONES OF THE CRANIUM.
183
point from which ossification begins, and where it is,
therefore, most perfect. But this is to admit a dan¬
gerous principle, that the forms of the bones are matter
of chance : and thence we are left without a motive
for study, and make no endeavour to comprehend the
uses of parts. We find that all the parts which are most
exposed to injury are thus strengthened; —the centre
of the forehead, the projecting point of the skull
behind, and the lateral centres of the parietal and
frontal bones. The parts of the head which would
strike upon the ground when the man falls, are
the strongest, and the projecting arch of the pa¬
rietal bone is a protection to the weaker temporal
bone.
If we compare the skull to the centering, where a
bridge is to be built over a navigable river, and con¬
sequently where the space must be free in the middle,
we find that the scientific workmen are careful, by
a transverse beam, to protect the points where the
principal thrust will be made in carrying up the
masonry: this beam does not act as a tie-beam, but
as a straining-piece, preventing, the arch from being
crushed in at this point.
ing of the puncheons* and rafters be not secure, it
will sink down in the form of the dotted line. The
workmen would apply braces at these angles to
strengthen them.
In the arch, and at the corresponding points of
the parietal bones, the object is attained by strengthen¬
ing these points by increase of their convexity and
thickness; and where the workman would support
g., of roofs. In this figure it
/ is clear, that the points A
I' A will receive the pressure
of the roof, and if the join-
The necessity of strength¬
ening certain points iswell
exhibited in the carpentry
* The puncheons are the upright lateral pieces; the rafters
are the timbers which lie oblique, and join the puncheons at AA.
N 4>
184
REVIEW OF THE BONES OF THE CRANIUM.
the angles by braces, there are ridges of bone, in the
calvaria *, or roof of the skull. If a stone arch fall,
it must give way in two places at the same time; the
centre cannot sink unless that part of the arch which
springs from the pier yields : and in all arches, from
the imperfect Roman arch to that built upon modern
principles, the aim of the architect is to give security
to this point.
In the Roman bridges still entire, the arch rises
high, with little inclination at the lower part; and
in bridges of a more modern date, we see a mass of
masonry erected on the pier, sometimes assuming the
form of ornament, sometimes of a tower or gateway,
but obviously intended at the same time, by the per¬
pendicular load, to resist the horizontal pressure of
the arch. If this be omitted in more modern build¬
ings, it is supplied by a finer art, which gives
security to the masonry of the pier (to use the terms
of anatomy), by its internal structure. In what is
termed Gothic architecture, we see a flying buttress,
springing from the outer wall, carried over the roof
of the aisle, and abutting against the wall of the
upper part, or clerestory. From the upright part of
this masonry, a pinnacle is raised, which at first
appears to be a mere ornament, but which is neces¬
sary, by its perpendicular weight, to counteract the
horizontal thrust of the arch.
By all this, we see that if the skull is to be con¬
sidered as an arch, and the parietal bones as forming
that arch, they must be secured at the temporal and
sphenoid t bones, the points from which they spring.
And, in point of fact, where is it that the skull yields
when a man falls, so as to strike the top of his head
upon the ground ? — in the temples. And yet the
joinings are so secure, that the extremity of the bone
does not start from its connexions. It must be frac-
* From the Latin calva or calvaria, a helmet.
f In the Greek, sphenoid—in the Latin, cuneiform — like a
wedge, because it is wedged among the other bones of the head;
but these processes, called wedges, are more like dovetails, which
enter into the irregularities of the bones, and hold them locked.
REVIEW OF THE BONES OF THE CRANIUM.
185
tured before it is spurred out, and in that case only
does the upper part of the arch yield.
But the best illustration of the form of the head
is the dome.
A dome is a vault rising from a circular or ellipti¬
cal base ; and the human skull is, in fact, an elliptical
surmounted dome, which latter term means that the
dome is higher than the radius of its base. Taking
this matter historically, we should presume that the
dome was the most difficult piece of architecture,
since the first dome erected appears to have been at
Rome, in the reign of Augustus — the Pantheon,
which is still entire. The dome of St. Sophia, in
Constantinople, built in the time of the Emperor
Justinian, fell three times during its erection : and
the dome of the Cathedral of Florence stood un¬
finished 120 years for want of an architect. Yet we
may, in one sense, say that every builder who tried
it, as well as every labourer employed, had the most
perfect model in his own head. It is obvious enough,
that the weight of the upper part of the dome must
disengage the stones from each other which form the
lower circle, and tend to break up their joinings, and
consequently to press or thrust outwards the cir¬
cular wall on which it rests. No walls can support
the weight, or rather the lateral thrust, unless each
stone of the dome be soldered to another, or the
whole hooped together and girded. The dome of
St. Paul's has a very strong double iron chain, linked
together, at the bottom of the cone ; and several
other lesser chains between that and the cupola,
which may be seen in the- section of St. Paul's
engraved by Hooker.
The bones of the head are securely bound together,
so that the anatomist finds, when every thing is gone,
save the bone itself, and there is neither muscle,
ligament, nor membrane of any kind, to connect the
bones, they are still securely joined, and it requires
his art to burst them asunder ; and for this purpose
he must employ a force which shall produce a uni¬
form pressure from the centre outwards ; and all the
REVIEW OF THE BONES OF THE CRANIUM.
sutures must receive the pressure at one time and
equally, or they will not give way. And now is the
time to observe another circumstance, which calls for
our admiration. So little of accident is there in the
joining of the bones, that the edge of a bone at the
suture lies over the adjoining bone at one part and
under it at another, which, with the dovetailing of
the suture, as before described, holds each bone in
its place firmly attached ; and it is this which gives
security to the dome of the cranium.
If we look at the skull in front, we may consider
the orbits of the eye as crypts under the greater
building. And these under-arches are groined, that
is to say, there are strong arched spines of bone,
which give strength sufficient to permit the inter¬
stices of the groinings, if I may so term them, to be
very thin. Betwixt the eye and the brain, the bone
is as thin as parchment; but if the anterior part of
the skull had to rest on this, the foundation would
be insufficient. This is the purpose of the strong
ridge of bone which runs up like a buttress from the
temple to the lateral part of the frontal bone, whilst
the arch forming the upper part of the orbit is very
strong : and these ridges of bone, when the skull
is formed with what we call a due regard to security,
give an extension to the forehead.*
In concluding this survey of the architecture of
the head, let us suppose it so expanded that we could
look upon it from within. In looking up to the
vault, we should at once perceive the application of
the groin in masonry ; for the groin is that projection
in the vault which results from the intersection of
two arches running in different directions. One rib
or groin extends from the centre of the frontal bone
to the most projecting part of the occipital foramen,
or opening on the back of the head ; the other rib
* Although they are solid arches connected with the building
of the cranium, and bear no relation to the surfaces of the brain,
the early craniologists would have persuaded us that their forms
correspond with the surfaces of the brain, and indicate parti¬
cular capacities or talents.
craniology.
crosses it from side to side of the occipital bone.
The point of intersection of these two groins is the
thickest and strongest part of the skull, and it is the
most exposed, since it is the part of the head which
would strike upon the ground when a man falls
backwards.
What is termed the base of the skull is strength¬
ened, if we may so express it, on the same principle :
it is like a cylinder groin, where the rib of an arch
does not terminate upon a buttress or pilaster, but is
continued round in the completion of the circle.
The base of the skull is irregular, and in many places
thin and weak, but these arched spines or ribs give it
strength to bear those shocks to which it is of course
liable at the joining of the skull with the spine.
CRANIOLOGY.
We possess a very remarkable power of discrimi¬
nating minute differences in the human countenance,
and slight variations of expression, although we are
so familiar with the exercise of this faculty, that it
ceases to be surprising. There are varieties in the
proportions of the head too, but we should be sadly
puzzled to discover our best friends by the most
careful inspection of their crania. While the design
of producing a variety in the faces of men, and a
power of expression, is obvious, it would be a useless
provision if we did not also possess a corresponding
capacity of minute observation of the human face.
One source of this capacity is, that our sympathies
are alive to every change of countenance; we are
naturally or instinctively led to peruse those features,
where every sentiment of the heart has a correspond¬
ing character displayed, which differ from the cha¬
racter of a language only in being transient. But
if nature had intended that we should estimate the
capacities or affections of our friends by a measure¬
ment of the skull, it is probable that she would not
have covered the head with hair, nor have left our
188
CRANIOLOGY.
hearts so little susceptible of impression from a bald
one.
Whilst there is a never failing source of interest
in the human countenance, it is probably conducive
to our happiness that our opinions of men, drawn
from this source, are not infallible. Yet disappoint¬
ment, and unrequited affection or friendship, cannot
erase that which is so deeply impressed on our
natures : we nevertheless do not cease to scan the
human features. Certain expressions go to our
hearts, and we love not merely the expression of
qualities, but the appropriate fitness of the counte¬
nance to express those qualities of mind which we
love.
Whilst there is so much instinctive feeling, and
such a mingling of accidental associations, in the
formation of our opinions on the beauty and fitness
of the human countenance, we must be liable to
continual delusion; and this is the source of the
popularity of works, in which the authors, like
Lavater, have sought to connect the intellectual
endowments with the features ; or, like Gall, sought
to discover the propensities of our natures in the
lesser irregularities of our skulls. We have a natural
propensity to examine the human countenance, and
we do, in fact, possess a certain natural power of
discrimination : we comprehend a part without the
aid of teaching, and we yield ourselves to the delu¬
sion, that by the lights of physiology the sphere of
our knowledge may be extended. But I apprehend
that this faculty is of the nature of those instinctive
powers that are matured early, and do not admit ot
unlimited improvement.
I may be permitted to touch upon a subject which
has too much interested my countrymen ; I mean
the opinion of Dr. Gall, that the propensities of our
nature may be ascertained by the protuberance of
certain parts of the skull. I shall confine myself to
the examination of the skull.
CRANIOLOGY'.
Iloxuxjar are the lesser convexities and irregularities
of the human skull to be attributed to the peculiar
form of the brain ?
In my lectures it is necessary to give a severe or
minute demonstration of the bones of the head ; and
for this purpose, I first exhibit the membrane, or
little vesicle that surrounds the brain in the foetus,
before any bone is formed. I then demonstrate,
that the several bones of the cranium are formed
betwixt the layers of that membrane; and that they
are necessarily adapted to the form of the brain
previously existing ; but when on that subject I
take occasion to remark that a pregnant error has
grown out of this demonstration, and one which,
though blown out to the extent of a splendid folio,
is only a more monstrous misconception. Some have
contemplated this matter, as if the brain and skull
were pieced together after the manner of a cunning
artificer, and not formed as a perfect whole. Has
not the skull those forms which best resist violence
from without ? Are not all the exposed parts strength¬
ened, and is not the substance ancl the internal
texture of the skull calculated to stop the vibrations
that would be conveyed through a helmet differently
constructed ? This much I shall prove. I may then
ask, is the brain, while it is yet exposed, and has no
bony covering, formed with a relation to the case
which is destined to cover it, or not ? Look to the
whole skeleton, and we shall find the answer; ob¬
serve how the bones are formed in their just propor¬
tions to bear the weight, and to move in certain
directions, long before they can be exposed to pres¬
sure, or put to use. How they are strengthened
with spines wherever the force is destined to be
applied ; how curiously fashioned at their extremities
to permit motion in the direction proper to the joint,
and consistent with the movement of the whole limb.
These provisions are made while the bones of the
extremities are soft and transparent cartilages, and
have not yet been put to their proper officesj and
CRANIOLOGY.
shall the skull, which is intended to protect the
noblest organ, be merely an accidental cast of the
brain : and can it be supposed that its forms bear no
relation to its proper office ? This cannot be ad¬
mitted ; it must be granted, that the skull bears
relation to external circumstances ; and if this be so,
must not the brain be formed with relation to the
skull, and to such forms of the skull as are capable
of protecting it ? It follows, therefore, that although
the skull be in close contact with the surface of the
brain, and formed over it; yet if the external shape
be obviously that which is best calculated to resist
injury from without, we must conclude that the
brain conforms to what is necessary in the shape of
the skull; and although first formed, that it is
bound up in that manner which shall best secure its
protection by bone. *
But I shall prove further, that the lesser promi¬
nences of the skull, which are adding strength to it,
result from circumstances quite independent of the
brain, and ought not, therefore, to be brought for¬
ward as indications of propensities of the mind.
In contemplating the forms of the skull, the eye
fixes naturally on the frontal bone, and on the
slightest, as on the most careful inspection, it ap¬
pears that the form of the bone on its lower part
has relation to the orbits of the eyes, and the organ
of smelling. It is evident, that but for the eyes
there would be no orbits, no lateral ridge of the
frontal bone, and no relative flatness of the temples;
and but for the developement of the cavities of the
nose, there would be nothing of that manly form
which is so necessary to the perfection of the coun¬
tenance ; no support for the eyebrows, and no space
for the muscles which move them ; the flat insipidity
of the child's forehead would be continued in after
age.
Higher on the frontal bone, and on the upper
division of the forehead, are two eminences, the
* All the viscera conform to a system of packing.
CRANIOLOGY.
191
eminentice front ales. When natural, they give a fine
variety of surface to the full and polished forehead ;
when not visible, there is a defect; when too pro¬
minent, there is a deformity. What are these ? Are
they indications of a corresponding prominence of
the brain ? by no means : they are obviously in¬
tended to give strength to these parts of the skull,
which are much exposed ; the bone is more raised
and arched at these two parts; and that this is
to afford protection, is demonstrated on making a
section of the bone, for the frontal bone is thicker at
these parts, and there is no concavity on the inside,
to correspond with the external convexities. Let
my reader here distinguish betwixt that opinion so
long and generally acknowledged to have a founda¬
tion in nature; — that a full and high forehead
indicates the perfection of the organ of the intellect;
and these new opinions, that the lesser irregularities
are produced by the greater developement of distinct
organs in the brain. To the former opinion, I shall
by experiments afford some support; the latter has
no foundation.
Let us now direct our attention to the prominence
of the parietal bone. If a man were to fall on the
side of the head, the injury would be inflicted on
the point of the utmost convexity, the lateral pro¬
jection : and here, where the bone assumes the
arched form of strength, we find that it is also in¬
creased in thickness. In this instance, as in the
forehead, the outward convexity, or the elevation of
the surface of the bone into a higher arch, bears no
relation to the surface of the brain beneath.
Suppose, again, that we were to place a weight,
accurately balanced, upon the top of the head ;
when the head was adjusted, so as to bear the
weight with most ease, we should find that it was
placed on the utmost convexity near the meeting
of the coronal and sagittal sutures, where the bone
rises into a fuller arch, I may say, the better to
sustain the weight. We shall also find, on sawing
the bone across here, that it is thicker, we must
CRANIOLOGY.
presume for the same purpose that its convexity is
increased, to give strength. I can have no doubt
that this is a provision for bearing burdens on the
head ; and certainly the outer convexity has no
relation to the form of the brain.
When we come round, in this examination, to the
back of the head, we cannot fail to observe, that
the occiput is least of all protected by the hands,
and therefore we may presume that it is best pro¬
tected by its form and thickness. The occipital
bone is crossed with spines, which centre in a
remarkable protuberance, which projects so as to
meet the ground when we fall backwards. Besides,
within, the occipital bone is in a manner groined,
with crossing arches of bone, which add much to
the strength of the skull at this part.
In short, after a general and unprejudiced inspec¬
tion of the shape of the skull, we must believe that
it is formed with reference to the pressure it has to
sustain from without, or of resistance to external
violence. If it be so, and the brain and skull are
close in contact, the former must be constituted with
reference to the latter. That the size and general
dimensions of the cranium do correspond with the
volume of the brain, there can be no doubt; but
the lesser convexities have no such relation to the
internal organ.
It is a strange delusion that would lead some men
to believe, that, in the outward configuration of the
skull, by which I mean the forms which have rela¬
tion to the organs of sight, smell, and voice, and
those spines and prominences which have respect
to the strength of the skull, or to the attachment
of muscles, they see the indications of particular
properties of the mind, or the organs of certain
propensities.
That the size of the brain-case, or the prevailing
form of the whole head, may not have some relation
to the perfection of the intellect, it would be bold to
affirm. Most anatomists have believed that they
have ; but we must distinguish this question from
9
NATIONAL VARIETIES.
the speculations of Drs.Gall and Spurzheim, opinions
which they have attempted to engraft upon the
acknowledgment of men every way worthy of
credit.
Varieties in the forms of the Head indicative of
national peculiarities.
It is impossible to conceal from ourselves, that
much theory, and a great deal of misplaced enthu¬
siasm, has had an influence on the opinions of phy¬
siologists, regarding the varieties of mankind. It
is, however, allowable to take as a principle, that
there will be a relation betwixt vigour of intellect
and perfection of form ; and that, therefore, history
will direct us to the original and chief family of
mankind. We therefore ask, which are the nations
that have excelled and figured in history, not only
as conquerors, but as forwarding, by their improve¬
ments in arts and sciences, the progress of human
knowledge ?
It is not to be denied, that there are national
peculiarities in the form of the skull, as there are of
features, of colour, and of general form. These, in
their extremes, are very distinct; but they are joined,
as it were, by intermediate degrees of difference ;
and there are distinctions to be observed in the
individuals of any one people, as great at least as
those which mark national peculiarity. There are
as great varieties among individuals of the tribes of
America or of Africa, as among the nations of Asia
or of Europe.
Among the ancient nations, one great character
seems to have prevailed : the Assyrians, Chaldeans,
Medes, Persians, Jews, the Greeks, and Romans,
appear to have had their origin and centre in the
Western part of Asia, perhaps betwixt the moun¬
tains of Caucasus and the Caspian Sea. To this
day there is in the people seated there, Circassians
and Georgians, a degree of beauty and perfection
of form, that at least agrees with this hypothesis ;
VOL. i. o
NATIONAL VARIETIES
and from this, as the centre of the old Continent
and of ancient nations, departure from a common
form of the head and features is to be observed in all
directions over the face of the globe. It is noticed
as we depart eastward through Tartary, and to the
extreme north-eastern parts of Asia even to Ame¬
rica. Again, departing from the centre, we may
descend south-east to the Peninsula of India, and
the Asiatic Islands, and to those of the great Pacific
Ocean. Or, on the other hand, we may trace a
change towards Egypt and the African varieties ;
or lastly, towards the western extremities of Europe ;
where in the extreme islands of the west, there is a
perfection of manly form and feminine beauty,
happily combined with qualities still more to be
esteemed, and which are now spread to the New
Continent, and destined to characterize the larger
portion of the inhabitants of our globe.
These varieties are distinguishable into five grand
families: I. In the people seated betwixt Mount
Caucasus and the Caspian, there is observed a due
balance betwixt the cranium and bones of the face,
that is a full developement of the cranium or brain-
case, and, as we may suppose, a perfection in the
organ of intellect; a due proportion betwixt the bones
of the face, both in comparison with the cranium and
amongst each other; so that the face is small, the
outline smooth, the contour of the features regular,
and there is no harshness from their undue promi¬
nence. With this there is combined beauty of the
frame generally : long hair and fair skin, and bloom¬
ing complexion, varying with emotion, and an index
of the mind not to be neglected in estimating the
perfection of the human body. This, is the white
variety of mankind, which spreads over Western Asia
and Europe. The form of the skull is considered as
the medium and more perfect form, betwixt the
Mongolian races, in which the face is compressed,
so as to be extended laterally, and the Ethiopian,
which exhibits the jaws lengthened, and the face pro¬
jecting from a receding forehead.
6
IN THE FORMS OF THE SKULL.
II. The Mongolian variety extends to the Cal-
mucks, the Tungooses of China, and round by
Siberia to the transition forms of the Esquimaux and
the Greenlander. The cranium is globular, the bones
of the face broad and flattened, the os frontis broad
and flat, the malar bones projecting laterally, the
orbits large and open, the superciliary ridges ele¬
vated, corresponding with the Calmuc countenance ;
the face is broad, the eyes are apart, and the space
betwixt them flat, the aperture of the eyelids is nar¬
row, and the nose round.
III. The third variety is the Ethiopian, and
comprehends the well-known African skull. The
head is the reverse of the globular form. The great,
peculiarity is not, as has been supposed, in the com¬
parative size of the bones of the face, over the
cranium, but merely in the size of the teeth and
jaws, and the forms of the bones connected with the
teeth in office, as giving origin to the muscles which
move the jaws ; and here I may observe, that what¬
ever peculiarity of form may distinguish the teeth
and jaws of any nation, there is always a corres¬
pondence in the soft parts placed over them, and
hence the thick and fleshy lips, and the heavy cheeks
of the African, are combined with their protuberant
jaws and teeth.*
IV. The fourth variety includes the native Ame¬
ricans ; and a race arriving from the eastern ex¬
tremity of Asia may be traced down the North
American continent, until it meets the natives of the
South, the Caribbees or Caribs, who have the bones
of the face broad, but not flat, prominent cheek
bones, a short forehead, the eyes deep, and the bones
of the nose developed, but the nose flattened.
V. The fifth is the Malay variety, which is inter¬
mediate betwixt the Asiatic and the Negro. It
# Some ycsrs ^go I made a comparison betw lxt the extreme
forms of the European and Negro skull. This I did by suspending
them on a rod introduced through the foramen magnum. I then
compared their position and the inclination of the facial line.
See the Philosophy of Expression, Second edition.
NATIONAL VARIETIES.
would appear as if mankind had spread more easily
by the influence of the winds and the currents of the
ocean, than by the regular progress of wandering
tribes. The peculiarities under this head may be
traced from the Red Sea, along the coasts of Hin-
doostan, through the Straits of Malacca, to the
islands of Sumatra, Java, and the Celebes, to New
Guinea, to New Holland, and Van Diemen's Land.
The skull of a Buggess, from the island of Celebes,
has the low forehead and the prominent jaws of the
Negro, with the lateral projection of the face of the
Mongolian variety, a combination which we might
expect on looking to the map of Eastern Asia. Cap¬
tain Cook has informed us, that among the Friendly
Islanders, he met with hundreds of European faces,
and "genuine Roman noses." In the islands of the
Pacific Ocean, there is scope for the re-union of the
families of mankind; arrivals from the North of the
American Continent: men sprung from the natives
of the Southern Continent of America : the Ethiopian
extreme, floating through the Eastern Archipelago,
and meeting the descending current of the maritime
people of China, Corea, and Japan, form varieties and
transitions. In the Marquesan, Society, Friendly,
and Sandwich islands, the Caucasian variety prevails,
and it meets in the New Hebrides and New Zealand
with the tribes of New Guinea and New Holland.
197
OF 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 com¬
posed t; for they have that mutual
dependence upon each other, that con¬
tinual circle of action and re-action in
their various functions, and that intri¬
cacy of connection, and close depen¬
dence, 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, so in the human body
there is 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
whatever 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.
As dead parts, the bones are the most permanent,
unchangeable parts of all the body; while as living-
parts, and partaking in the laws of the living system,
their substance changes continually. We see them
exposed to the seasons, without suffering the smallest
* I have arranged the preparations illustrative of the growth
and structure of bone, so as to correspond with this dissertation.
This referred to the collection which is now in the possession of
the College of Surgeons of Edinburgh ; but the series is complete
in the Anatomical Museum in the London University.
f This figure represents the skeleton of the arm of the foetus ;
it is dried, and while the cartilages have shrunk and become of a
dark colour, the portions of the bones which have begun to form
are visible in the scapula, clavicle, humerus, radius, and ulna, the
metacarpal bones, and some of the phalanges of the fingers.
o 3
OF THE FORMATION
change; remaining for ages the memorials of the
dead; the evidence of a former race of men, or of
animals which have ceased to exist since the last
great revolution of our globe; the proofs of such
changes on our globe as we cannot trace but by
these uncertain marks. It is from such circumstances
that 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^ and as subject
to change ; having, like them, their periods of growth
and decay; that they are more liable to accidents,
and as subject to internal disease.
According to the chemists bone consists of albu¬
men, a little jelly, and the earth of bone, the proper
hardening material which gives the property of
resistance.* This earth of bone consists of 82 parts
in the hundred of phosphate of lime, the remainder
containing fluate and carbonate of lime, with the
phosphates of magnesia and soda.
I have a notion that some of these may be products
arising out of the processes employed.
The phenomena of fractured bones first suggested
some indistinct 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 thought that he had
seen, in a case of scrophulous bone, an exudation
which flowed out like wax, and hardened into perfect
bone. Daventer, that he had seen the juice exuding
* M. Herissant has some merit in the investigation of this
subject. See Memoires Acad, pour 1758, p. 322. Malpighi is
considered to be the first who announced that the basis of bone
was an animal matter, like cellular membrane.
AND GROWTH OF BONES.
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 believe, 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 suc¬
cessive conditions of a thin uncoagulated juice, of a
transparent cartilage, and of soft and flexible bone,
became at last, by a slow coagulation, 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. This opinion,
erroneous as we now know it to be, once prevailed ;
and if other theories were at that time proposed,
they did not vary in any very essential point from
this first notion. De Heide, 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 broken
bone ; and he has 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 cartilaginous, 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 experiments, 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
o 4
200
OF THE FORMATION
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 ot secre¬
tion, 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 repaired 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 adhesion to
the broken bone, was easily separated from the broken
ends, which remained rough and bare ; and, in pur¬
suing these dissections, he found the periosteum
fairly glued to the external surface of the new bone ;
or he found rather the callus or regenerated bone
to be but a mere thickening of the periosteum, its
layers being separated, and its substance swelled.
On the first days he found the periosteum thickened,
inflamed, 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 unchanged, or only a little
roughened by the first layer of the 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 surface 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 sub-
* The periosteum is the membrane which surrounds and is
attached to the surface of the bone, and which conveys the blood¬
vessels to it.
AND GROWTH OF BONES.
201
stance, proceeding from the periosteum, which was
thickened all round them. In an early stage, this
plug could, by drawing the periosteum, be pulled
out from its hole: in a more advanced stage, it was
inseparably united to the bone so as to supply the
loss.
Haller, doubting whether the periosteum, a thin
and delicate membrane, could form so large a mass
of bone or callus, repeated the proofs, and he again
found quite the reverse of all this : that the callus, or
the original bone, was in no degree dependent on the
periosteum, but was generated from the internal
vessels of the bone itself; that the periosteum did
indeed appear as early as the cartilage which is to
produce 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 nuclei, in the very centre of their cartilage, or
in the very centre of the yet flexible callus, far from
the surface, where they might be assisted by the
periostelim ; and here it is justice to add, that while
these questions were agitated on the continent,
Dr. William Hunter had proved that the callus of
broken bones was organized, and that the secretion
of bone into it proceeded from the arteries taking
on them a new action, and secreting the earthy
matter into the first formed substance.
Thus has the formation of bone been falsely attri¬
buted to a gelatinous effusion, gradually hardened ;
or to that blood which must be poured out from the
ruptured vessels round the fractured bone ; or to the
induration and change of the periosteum, depositing
layer after layer, till it completed the form of the bone.
OF THE FORMATION
But when, neglecting theory, we set ourselves to
examine, with an unbiassed judgment, the process of
nature in forming 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 recorded 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 in-
organized, and out of the system, not subject to
change, nor open to disease ; liable, indeed, to be
broken, but without any means of being healed
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 te softer parts are. We are not to refer
the generation and growth of bone to any one part.
It is not formed by that jelly in which the bone is
laid, nor by the blood which is circulating in it, nor
by the periosteum which covers it, nor by the medul¬
lary membrane with which it is lined ; but the whole
system of the bone, of which these are parts only, is
designed and planned, is laid out in the very elements
of the body, and goes on to ripeness, by the concur¬
ring action of all its parts. The arteries, veins, and
lymphatics exist, in the cartilage or the membranes,
before bone is formed. At a certain regular period,
the arteries, by a determined action, deposit the
bone ; which is formed commonly in a bed of cartil¬
age, 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.
My readers understand that cartilage is a substi¬
tute for bone in the early months of the foetus ; that
at a regulated period in each bone, at a given point,
* The obscurity on this subject is from the neglect of defined
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.
AND GROWTH OF BONES.
203
and in a perfectly regular manner, portions of the
cartilage are absorbed, and bone deposited.
This cartilage never is hardened into bone; but,
from the first, it is in itself an organized mass. It has
its vessels, which are at first transparent, but which
soon dilate ; and whenever the red colour of the
blood begins to appear in them, ossification very
quickly follows.* The first mark of
ossification is an artery, which is seen
running into the centre of the cartil¬
age, 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 ossi¬
fication begins, stretching its rays ac¬
cording to the length of the bone, 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 ossification are
successively formed ; always the ossi¬
fication is foretold by the spreading of
the artery, and by the arrival of red blood. Every
point of ossification has its little arteries, and each
ossifying nucleus has so little dependence on the
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 ossification drops sponta¬
neously from the cartilage, leaving the cartilage like
a ring, with a smooth and regular hole where the
bone lay. This is because the cartilage was a sub-
* This figure represents the tibia of a foetus cut through. The
central part (diaphysis) is already bony; but the extremities are
yet cartilage. The red blood is, however, entering the arteries
and veins in the cartilaginous extremities ; and the black spots in
the midst of the cartilage mark the beginning of ossification, and
formation of the epiphysis.
204
OF THE FORMATION
stitute for the bone, and, because preparatory to the
formation of the nucleus of bone, the cartilage is ab¬
sorbed, and a bed prepared for the new formation.
The colour of each part of a bone is proportioned
exactly to the degree in which its ossification is ad¬
vanced. When ossification begins in the centre of
the bone, redness also appears, indicating the presence
of those vessels by which the bony matter is to be
poured out. When the bony matter begins to accu¬
mulate, the red colour of those arteries is obscured,
the centre of the bone becomes yellow or white, and
the colour removes towards the ends of the bone. In
the centre, the first colouring of the bone is a cloudy,
diffused, and general red, because the vessels are pro¬
fuse. 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 yellow and opaque. On
either side of that, there is a zone of red: on
either side of that, again, the vessels being more spa¬
ringly distributed, form a vascular zone, and the zone
at either end is transparent cartilage.* The ossifica-
* It is curious to observe how completely vascular the bones of
a chicken are before the ossifications have fairly begun; how the
ossifications, being begun, overtake the arteries, and hide them,
changing the transparent and vascular part of the bone into an
opaque white; how, by peeling off the periosteum, bloody dots
are seen, which show a living connection and commerce of vessels
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 cartila¬
ginous state: and then the vessels appear in such profusion, that
AND GROWTH OF BONES.
205
tion follows the vessels, 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 each
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 extremities 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.
Now we know the difference of apophysis and
epiphysis, for anatomists make a sort of juggle be¬
twixt these names, as if they were engaged in im¬
portant matters. The apophysis is a process, or
projection of bone. The epiphysis is the distinct
portion of the bone, which is formed in a distinct
nucleus of bone, and becomes afterwards joined and
incorporated with the main body of the bone, and
may then be described as an apophysis.
It is more important a great deal to observe, that
as the extremities of the long bones forming the
articulations are joined to the bodies or shafts by
cartilage in childhood and adolescence, they are
subject to be torn off, and to present a very puzzling
case, that is, a fracture without crepitus ; for as the
crepitus of the fractured bone arises from the irre¬
gularity of the broken ends, and as in this sort of
fracture [or diastasis] the surfaces are smooth, the
surgeon is liable to be deceived, and the patient to
permanent lameness and distortion. I have some
specimens in my museum of this accident.
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
parts.
206
OF THE FORMATION
The vessels may be seen entering in one large
trunk (the nutritious artery) into the middle of the
bone.* From that centre they extend towards both
ends, and the fibres of the bone extend 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, every artery piling
it up on each side to form its ridge ; yet 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 secretion from their
sides; so as to pile up the ridge of bone in their
course. The secretion is performed in their very
extremities. 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 assistant arteries from without, which
meet the internal trunks, and assist the ossification ;
which, with every help, is not accomplished in many
years.
It is by the action of the vessels that all the parts
of the human 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 prepared by
the actions of the greater system, the actions of
particular vessels prepare various parts : some to be
added to the mass of solids, for the natural growth;
* This is an important point of demonstration, because the
artery, though small, acquires importance from its place. See
Demonstration of the Femur and of the Tibia.
AND GROWTH OF BONES.
others to supply the continual waste, or to allow new
matter to be received ; others to be discharged from
the body as effete and hurtful, as the secretions into
the intestines, and from the kidney and from the
skin ; others again to perform certain offices within
the body, as saliva, bile, or pancreatic fluid. Thus
the body is furnished with various apparatus for
performing various offices, and for repairing the
waste. These are the secretions, and the formation
of bone is one of these. The plan of the whole
body lies in the embryo, in perfect order, with all its
forms and parts. Cartilage is laid in the place of
bone, and preserves its form for the future bone,
with all its apparatus of surrounding membranes, its
heads, its processes, and its connection with the soft
parts. The colourless arteries of this pellucid but
organized mass of cartilage keep it in growth, ex¬
tend, and yet preserve its form, and gradually
enlarging in their own diameter, at last receive the
entire blood.* Then the deposition of earthy matter
begins. The bone is deposited in specks, which
spread and meet and form themselves into perfect
bone. While the bone is laid by arteries, the carti¬
lage 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
consistence.
If the organization of arteries and veins, arteries
to deposit bone, and absorbents to take up the carti-
* Previous to the formation of bone, (or the preparation for it,)
in the cartilage, 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 animal, previous to the formation of bone
in it.
However, the change, previous to the deposition of bone, has
not been very accurately noticed: the firm cartilage suffers a
change : there is a tract from the circumference 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.
208
OF THE FORMATION
lage, and make room for the osseous matter, be
necessary in the formation and growth, it is no less
necessary for the life and health of the full formed
bone. Its natural condition 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, and spoil, to become brittle
by too much secreted earth, or to become soft by a
deficient secretion, or by a greedy diseased absorp¬
tion of its earthy parts. The cartilage is in itself
a secretion, to which the full secretion of bone
succeeds.
In the re-union of a fractured bone, we have to
observe nearly the same phenomena which accom¬
pany its first formation.
The first effect is the tearing of the periosteum
and surrounding cellular textures, and perhaps some
part of the muscular substance. The consequence
of which is, that the broken extremities are sur¬
rounded with coagulum of blood. 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 uni¬
form 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 surround¬
ing parts do not shoot into it, but veins, as well as
arteries and absorbents, inosculate with the vessels of
this new formed matter ; and whatever vessels may,
by accidental contact, inosculate with this substance,
whether coming from bone, muscles, or membrane,
still bone is formed, because it is the destined con¬
stitution of the new formed mass, or rather of the
vessels which are already in it to form bone.
If the broken limb be too much moved during the
cure, then are the secreting arteries interrupted in
their office, perfect bone is never formed, it remains
a cartilage, and an unnatural joint is at length pro¬
duced ; but by injuring the bone the vessels are
opened again, tne process is renewed, and the bones
unite ; or even by rubbing, by stimulating, by merely
7
AND GROWTH OF BONES.
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 ; they remove the cartilage as the bone
is laid ; they continue removing the bony particles
also, which the arteries continually renew.
Nothing can be more curious than this continual
renovation and change of parts, even in the hardest
bones. We are accustomed to say of the whole
body, that it is daily changed; that the older par¬
ticles 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 dis¬
covered by chance, that animals fed upon the refuse
of the dyer's vats received so much of the colour¬
ing 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
ligaments 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 appears in
their bones, is removed, and appears again with such
a sudden change as proves a rapidity of deposition
and absorption, exceeding all likelihood or belief.
All the bones are tinged in twenty-four hours ; in
two or three days their colour is very deep ; and if
the madder be left off but for a few days, the red
colour is entirely removed.
* Those principles become of the utmost importance in the
practice of surgery.
VOL. I. P
210
OF THE FORMATION
This tinging of the bones with madder, was the
great instrument in the hands of Du Hamel, for
proving by demonstration, 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 esta¬
blishing a doctrine on facts, is too easily seen here.
Du Hamel, believing that the periosteum deposited
successive layers, which were added to the bone, it
was his business to prove that the successive layers
would be deposited alternately red, white, and red
again, by giving a young animal madder, withhold¬
ing 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 successive
times in which the periosteum is able to deposit the
layers of its substance, but Du Hamel very thought¬
lessly 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 proceeded 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 con¬
tinually accumulated upon each other every week,
what kind of a bone should this grow to ? Yet such
is the fascinating nature of a theory, that Du Hamel,
unmindful of any interruptions like those, describes
boldly his successive layers, carrying us through
regular details, experiment after experiment, till at
last he brings up his report to the amount of five
successive layers, viz. two red layers, and three
10
AND GROWTH OF BONES.
211
white ones. And in one experiment lie 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 of the madder gradually
leave the bones in not many days.
I have before me preparations in which we see
three distinct layers; and of the general fact there
can be no doubt. If I doubt the exhibition of six
layers, yet we may draw the same important conclu¬
sion from three as from six. Mr. John Hunter said,
that in the growth of bone, the inner part was ab¬
sorbed, while the outer surface had addition ; and
that the whole bone did not extend, but that the ex¬
tension of the shaft resulted from an addition to the
extremity. But be it at the same time understood,
that while the additional increment is 011 the surfaces
and the extremities of the bone, the whole substance^
of the bone is submitting to change.
By these experiments with madder, one most im¬
portant fact is proved to us ; that the arteries and
absorbents, acting in concert, alternately deposit and
re-absorb the earthy particles, as fast as can be con¬
ceived of the soft parts, or even of the most move¬
able and fluctuating humours of the body. The
absorption of the hardest bones is proved by daily
observation ; when a carious bone disappears before
the integuments are opened ; when a tumour, press¬
ing upon a bone, destroys it; when an aneurism of
the temporal artery destroys the skull; when aneur¬
ism of the heart beats open the thorax, destroying
the sternum and ribs ; when 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 mollities ossium, a disease by which,
p 2
<212
OF THE FORMATION
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 gra¬
dual softening of the bones, so that they bend under
the weight 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 thoroughly softened as
to be cut with the knife.*
Thus every bone has, like the soft parts, its arte¬
ries, veins, and absorbent vessels ; and every bone
has its nerves too. We see them entering into its
substance in small threads, as on the surfaces of the
frontal and parietal bones : we see them entering for
particular purposes, by a large and peculiar hole, as
the nerves which go into the jaws to reach the teeth:
we find delicate nerves going into each bone along
with its nutritious vessels ; and yet we dare hardly
believe the demonstration, 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 amputation;
or when, in a broken limb, we cut off with pincers
the protruding end of a bone : we feel no pain when
a bone is trepanned, or when caustics are applied to
it; and it has been always known, that the heated
irons, which the old surgeons used so much, made
no other impression than to excite a particular titil-
lation and heat, rather pleasant than painful, running
along the course of the bone. But there is a decep¬
tion 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
* See the examples of distortion in my former Collection, and
in particular the skeleton of the woman who died in consequence
of the Cesarean operation.
AND GROWTH OF BONES.
213
not send its sensations to the brain. It is not fit
that parts should feel in this sense, which are so con¬
tinually exposed to shocks and blows, and all the
accidents of life ; which have to suffer all the motions
which the other parts require. In this sense, the
bones, the cartilages, ligaments, bursae, and all the
parts that relate to joints, are quite insensible and
dead. A bone does not feel, or its feelings are not
conveyed to the brain ; but except in the absence
of pain, it shows every mark of life. Scrape a bone,
and its vessels bleed; cut or bore a bone, and its
granulations sprout up ; break a bone, and it will
heal; or cut a piece of it away, and more bone will
readily be produced ; hurt it in any way, and it in¬
flames ; burn it, and it dies. This is a deep subject,
but a very curious one. The meaning attached to
common terms of speech are not applicable here ;
and hence the obscurity. We would require to define
sensation, sensibility, and pain ; the liability of the
part to be injured and excited to inflame, and the
perception of that injury. I come to this conclu¬
sion : — The sensation of pain is bestowed as a
safeguard to the frame, forcing us to avoid what¬
ever 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 sen¬
sible. The sensibility possessed by the skin would
not be sufficient protection to the eye ; and it differs
in kind as well as in degree. Experiments have
been made by cutting and burning the bones and
tendons, and the conclusion has been, that they
were insensible. But when a man sprains his ankle-
joint, he is in extreme pain, though he can easily
satisfy himself that the pain he feels is not in the
skin, but must be in the joint and tendons. It
appears, then, that such parts, usually thought insen¬
sible, feel pain, and can propagate that pain to the
sensorium ; and further, that the peculiar sensibilities
are so suited as to allow of the free and natural mo¬
tion, and of the necessary degree of attrition, but are
p 3
214
OF THE FORMATION
bestowed for the purpose of making us avoid that
degree of violence, which would endanger the texture
or healthy function of the part.
We have further to understand, that if there be
any doubt of the sensibility of a bone, it is only
when it is in health ; for when inflamed, it becomes
exquisitely sensible. When the texture of a bone
is 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 in¬
creased by disease, the bones, ligaments, bursas, and
all the parts whose feeling, during health, is obscure
and hardly known, are roused to a degree of sensi¬
bility 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.
Ossification is a process which, at first, appears so
rapid, that we should expect it to be soon complete ;
but it becomes in the end a slow and difficult process.
It is rapid at first; it advances slowly after birth ;
it is not completed till the twentieth year ; it is for¬
warded by health and strength, retarded by weak¬
ness and disease. In scrophula it is imperfect,
because there is an imperfect assimilation of food,
and the earth of bone is not furnished or not secreted
into the bone ; and so children become ricketty,
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 dreadful disease, when more or less heat,
during the incubation of a chick, prevents the
growth of its bones ; when the sickness of a crea¬
ture, during our experiments, protracts the growth
of callus ; when, in the accidents of pregnancy, of
profuse suppuration, or of languid health, the knit¬
ting of broken bones is delayed, or prevented quite ?
AND GROWTH OF BONES.
215
This process, so difficult and slow, is assisted by
every provision 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 perfect 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.
We have understood that the bones of the head
have membranes as their substitutes, as the long
bones have cartilage. The ossification,
for example, of the frontal or parietal
bone begins ill a point (as here repre¬
sented) ; a few delicate meshes of bony
matter are formed in the interstices of
the membrane. The membrane is by this means
split into two other membranes, we afterwards recog¬
nize under the names of pericranium and dura mater.
In this figure we have the commencement of the one
half of the frontal bone. On the extreme margin
we see through the meshes or net-work of new bone ;
but other layers of bone similar
to this are superadded, and the
interstices of the first layer
being opposed to the wire-work
of the second, a solid appear¬
ance and opacity is produced.
In a further state of advance¬
ment the bone assumes this appearance, and the
filaments diverge regularly from the centre, which
was the original spot where the ossification com¬
menced.
p 4,
21G
OF THE FORMATION
It is thus that in the bones * of the skull ossifi¬
cation 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. 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.
In the original cartilage of the long bones there
is no hollow nor cavity; it is all one solid mass.
When the ossification first appears, the cavity of the
bone also begins, and extends with the ossification :
at first the cavity is confined chiefly to the middle
of the bone, and extends very slowly towards the
ends. This cavity in the centre of the bone is at
first smooth, covered with an internal membrane,
containing the trunks and branchings of the nutri¬
tious vessels, which enter by a great hole in the
* The brain of the foetus while of the size of a hazel-nut is in.
vested with a membrane, in which there is as yet no speck of bone.
In the third month the ossification of the cranial bones commence,
and the first process exhibits a very beautiful net of ossific wire-
work. In a circle, the diameter 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 deposited, and
this superimposed net-work of bone is finer than the first: the
meshes being smaller and the bony matter more abundant. The
holes of the second net 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 processes of bone intervening ribs are formed irre¬
gularly, 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
ossification.
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 deposit of earthy
matter without organic structure.
13
AND GROWTH OF BONES.
middle of the bone; and the cavity is traversed with
divisions of its lining membrane, which, like a net¬
work of partitions, conduct its branches to all parts
of the 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.
In the middle of the bone the cavity is small, the
walls thick, and having all their bony plates; the
cells of net-work few, and large; but towards the
ends the bone swells out, the cavity also is large ; but
it is not like that in the middle, a large tubular
cavity: it is so crossed with lattice-work, with small
interstices and cells, that it seems all one spongy
mass of bone ; and so many of the inner layers are
separated, to form this profusion of cells, that the
whole substance of the bone has degenerated into
this lattice-work, leaving only a thin outward shell.
This reticular form is what anatomists call the can-
celli, lattice-work, net-work, or alveolar part of the
bone : it is all lined with one delicate membrane, and
inward partitions of the same lining membrane cover
each division of the lattice-work, forming each cell
into a distinct cavity. In these cavities, or cells,
the marrow is secreted. The secretion is thin and
bloody in children; it thickens as we advance in
years; it is a dense oil or marrow in the adult.
The 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 hang¬
ing by its stalk. The globules, when seen with the
microscope, are neat, round, and white, resembling
small pearls; and each stalk is seen to be a small
artery, which comes along the membrane of the can-
celli, spreads its branches beautifully on the surface
of the bag, and serves to secrete the marrow, each
small twig of artery filling its peculiar cell. To this,
an old anatomist added, that they had their contrac¬
tile power, like the urinary bladder, for expelling
218
OF THE FORMATION
their contents ; that they squeezed their marrow,
by channels of communication, 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; which is now known
to be pure fancy, and to have no foundation.
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 lamellae attracted particular
notice. Malphigi had first observed 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 exposed, 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 toge¬
ther 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, t
* There is no proof of the bones being lamellated. As to the
exfoliation of bone, the dead portion is generally irregular 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 by absorption of its particles, 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 only dead upon the surface.
In regard to the breaking up of the surface of the cranial bones,
when they lie exposed, the scales are similar to those from stones
or metals exposed to the influence of the air, and moisture, and
varying temperature : the thickness and succession of exfoliations
depend on the operation of the weather, not on the original for¬
mation of the bone. I have never seen heat produce a lamel¬
lated decomposition of bone.
f These nails Gagliardi imagined were no more than the little
irregularities, risings, and hollows of the adjoining plates, by
which they are connected.
AND GROWTH OF BONES.
219
Another notable discovery was the use of the
holes, which are very easily seen through the sub¬
stance of bones, and among their plates. They are,
indeed, no more than the ways by which the vessels
pass into the bones; but the older anatomists ima¬
gined them to be still more important, allowing the
matter to transude through all the substance of the
bone, and keep it soft. Now this notion of lubricating
the earthy parts of a bone, like the common talk of
fomentations to the internal parts of the body, is very
mechanical, and very ignorant; for the internal
parts of the body are both hot and moist of them¬
selves, 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 lubricated, unless by a fuller and
quicker circulation of its blood. It must be pre¬
served by that moisture only which exists in its sub¬
stance, and must depend for its consistence upon its
own constitution; upon the due mixing up of its
membrane, cartilage, and earth. Every part is pre¬
served in its due consistence by the vessels which
supply it; and I should no more suppose fat neces¬
sary for preserving the moistness of a bone, than for
preventing brittleness in the eye. This marrow is,
perhaps, more an accidental deposition than we, at
first sight, believe. We, indeed, find it in 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 cannot 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.*
* If we look to the difference there is in the adipose mem¬
brane, we shall find it more apparent than real. The fat on the
soles of the feet and palms of the hands is particularly firm, but
this firmness results from the strong intertexture of filaments of
a tendinous strength. The fat in the exposed parts of the limbs
220
OF THE FORMATION
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 con¬
nected with the fat than with the bone; and in
animals, can be drawn out entire from the cavity of
the bone; but its chief use is to conduct the vessels
which are to enter into the substance of the bone.
The periosteum, the outer membrane of bone,
which was once referred to the dura mater*, is merely
condensed cellular substance ; of which kind of
matter we now trace many varied forms and uses,
for so close is the connection of the periosteum, ten¬
dons, ligaments, fasciae, and bursas, and so much are
these parts alike in their nature and properties, that
we reckon them but as varied forms of one common
substance, serving for various uses in different parts.
The periosteum consists of many layers, accumulated
and condensed 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 peri¬
osteum 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
directions of the bony fibres. The periosteum is
looser in its texture outwardly, where it is reticulated
and lax, changing imperceptibly into the common
cellular substance. There , the fibres of the perios¬
teum assume the directions of the muscles, tendons,
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.
* Sec what is said under the head of membranes.
AND GROWTH OF BONES.
221
or other parts which run over it. Any accident
which spoils the bone of its periosteum, endangers
the life of the bone itself. The surface of the bone
becomes first affected, and then it exfoliates; the
accidental wounds of the periosteum, deep ulcers of
the soft parts, as on the shin, the beating of aneu¬
risms, the growth of tumours, the pressure even of
any external body, will, by hurting the periosteum,
cause exfoliation.
The cartilages are also a part of the living system
of the bone ; and we see too well, in the question of
the bones themselves, 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 be¬
comes 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.
We now understand the constitution of a bone,
and can compare it fairly with the soft parts in vas¬
cularity, 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 pro¬
cesses and heads, keeping it sound and in good
health, and regulating the degree of bony matter,
that the composition may neither be too brittle nor
too soft. From this constitution of a bone, we could
easily foresee how the callus for uniting broken bones
must be formed ; not by a mere coagulation of extra-
222
OF THE FORMATION
vasated juice, but by a new organization resembling
the original bone.
The primordium of all the parts of the body is a
thin coagulated mass, 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 a fluid which coagulates, which is soon
animated by vessels coming into it from every point.
In every external wound, in every internal inflam¬
mation, wherever external parts are to be healed, or
internal viscera are about to adhere, matter of this
kind is secreted, which serves as a bed or nidus, in
which the vessels spread from point to point, till the
part is fully organized, and it is in this manner that
the heart, the intestines, the testicle, and other parts,
adhere by inflammation to the coats which surround
them, and which are naturally loose. It is by a process
not dissimilar that the broken ends of bones unite..
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 ? How little the constitution of
a bone has been understood, we may know from the
strange debates which have subsisted so long about
the proper organ for generating callus. Some have
pronounced it to be the periosteum ; others the
medullary vessel, and internal membrane; others
the substance of the bone itself. In the heat of this
dispute, one of the most eminent anatomists pro¬
duced 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 pre¬
sently another anatomist 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 remained sound, or must have been
secreted by the medullary vessels. But the truth is,
AND GROWTH OF BONES.
223
that callus may be thus produced from any part of
the system of a bone.* If we pierce the bone of any
animal, and destroy the marrow, the old bone dies,
and a new one is formed around the old: if we kill
the creature early, we find the new bone to be a mere
secretion from the old bone ; and if we wait the com¬
pletion of the process, we find the new bone beau¬
tiful, 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, and that it has
become dead and black.t If we re¬
verse this operation, and destroy the
periosteum only, leaving the nutri¬
tious vessels entire, then the new bone
is formed fresh and vascular by the
medullary vessels, and the old one,
quite black and dead, surrounds it.t
The effect of injury to a living
bone is very curious. But the man¬
ner in which the bone resumes its
pristine form is still more worthy of
observation. At first, the outward
exfoliation is attended with a propor¬
tionate 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 ab¬
sorbed or discharged. But after
years these changes are again re¬
versed, and the new bone contracts
* In the experiments and observations 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 inflames and begins the new formation, before the
continued irritation in the centre kills it. C. B.
f The figure represents the necrosed bone, the new bone, soft
and irregular around the old.
J When I injured the marrow of the bone, necrosis was the con¬
sequence. When I deprived the bone of its periosteum and sur-
OF THE FORMATION
rounded it with a bit of bladder, I found the whole surface exfo¬
liated, and the cavity of the bone filled up; but this was 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 precisely 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. C. B.
* This figure is a plan of necrosis. The shaft of the old bone
is dark; the new bone is in outline; and now we perceive how
the new bone encloses the old, and how it forms the medium of
union betwixt the two extremities, after the old bone is loose or
altogether cast out.
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
wr example of the influence of that prin-
P i§ ciple which controuls the growth of
M sfT all the parts of the body, which may
fHfillJ % have its operation deranged by violent
injury or by disease ; but which will
at last, by slow degrees, restore the
part to its natural form and action.*
The diseases of the bones are the
most frequent in surgery; and it is
impossible to express how much the
surgeon is concerned in obtaining
true ideas of the structure, constitu¬
tion, and diseases of bones; how
tedious, how painful, and how loath¬
some they are ; how often the patient
may 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.
225
OF THE TEETH.
The structure, and growth, and decay of the teeth,
are subjects of considerable interest.
Considering the teeth generally, as belonging to
man and brutes, they are for masticating the food;
they are for retaining the prey; they are weapons of
defence; in some classes they are for digging and
searching for food ; and in some animals we can see
no other use than for defending the eyes, as in the
sus aethiopicus. Nor are we to consider them as
exclusively belonging to the jaws, for they are some¬
times seated in the back part of the mouth ; and in
fishes we find them in the beginning of the oesopha¬
gus, or at its termination, as in the crab and lobster.
The teeth differ from common bone : they are not
only harder, but 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 circumstances ;
though worn by friction, they are not excited to
diseased action; their mode of formation is peculiar,
and so is the manner of their decay: and all these
instances of their being different from common bone
are so many reasons for instituting a distinct enquiry
into their structure.
These peculiarities impose the necessity of a double
set of teeth, since they cannot accommodate them¬
selves by growth to the increasing size and strength
of the jaws ; it follows, that they must yield in suc¬
cession, and that a double set be provided. The first
set is called the milk teeth, or deciduous set of
teeth ; the second, the adult teeth. We shall begin
this description with the perfect adult teeth.
vol, i. q
226
of the teeth.
description of the human adult teeth.
There are thirty-two teeth in the adult skull.
These are divided into classes, according to their
form and use. There are eight incisores; four
cuspidati, or canine teeth; eight bicuspides; and
twelve molares, or grinding teeth.
Every tooth has three parts ; the crown, neck,
and fang or root.
Incisores.—The crown of the incisor tooth is
a wedge, having its anterior and posterior surface
inclined and meeting in a sharp edge. On the fore¬
part the surface is convex ; on the inside the surface
is concave; and viewing the tooth laterally, it is
broader and flat near the neck, and rising pyramidal
towards the cutting 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 project 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 becomes smooth, and the horse loses the
mark.
In some animals, as in the rodentia, the front
teeth are still better formed for cutting ; but as they
suffer attrition, in order to preserve the outer edge
sharp, they have a peculiar structure. They are so
* And as, indeed, we sometimes see in the human teeth.
of the teeth.
deeply socketed, that they reach the whole length
of the jaw, and they are provided with a continual
growth from behind, which pushes the tooth out in
proportion as it is worn away on the fore part. The
enamel in these animals is more accumulated on the
anterior edge of the tooth, so that the edge stands
up fine and sharp.
The cuspidati, or canine teeth, are next in
order, counting backwards. They are two in num¬
ber in each jaw. They have a general resemblance
to the incisor teeth, for when their points are worn
off, they are hardly distinguishable. Their fangs are
longer, and being the corner teeth of the jaw, and
deeply socketed, they form the strength of the front
teeth. Their principal distinction is in the form of
the upper part of the crown, which is like a spear,
having a point with two lateral shoulders.
In the larger carnivorous mammalia, this order of
teeth is of terrific length, whilst the front teeth are
small and carved. The spiral tusk of the narwhal
and the tusks of the walrus belong to this division of
the teeth : so do the tusks of the babyroussa, which
turn up 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 intermediate between these two orders.
They are sometimes called the lesser molares, being
in truth grinding teeth. The crown of the bicuspis
rises in two sharp points, so that they are like two
cuspidati incorporated, and their fangs prove this to
be the case ; for whilst they are always flatter and
shorter than those of the cuspidati, they have often
a division, and sometimes there are distinctly two
q 2
228
of the teeth.
fangs: their roots are oftener curved than those of
the other teeth. The second bicuspis is sometimes
wanting.
Molares, or grinding teeth, are six in each jaw.
The form of the crown is an oblong square. They
have four or more projections on their upper surface,
and they are covered with enamel to a uniform level,
and form indeed an approximation to the gramini¬
vorous tooth, since these regular projections being-
covered with enamel, a portion of the enamel remains
in the depressions when the projections have been
worn down ; and this is sufficient in a certain degree
to save the remaining part of the tooth from wasting
rapidly under attrition. The lower grinders have
two separate 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 grind¬
ing surface correspond with the points of the cuspi¬
dati, and the fangs correspond with the projections
of the crown; for although there are only two or
three roots to each grinding tooth, yet we may dis¬
cover that there would be always four fangs if they
were disjoined.
The term grinder is not good in comparative
anatomy, for in brutes of prey they are compressed,
and terminate in' three sharp processes, and these in
the closing of the jaw intersect each other like the
blades of scissars.
These four orders make the full number of thirty-
two teeth in the adult jaws.
On the whole the teeth of man are peculiar, in
being on a level, and being more nearly of one
length than any instance which we observe in brutes.
In all other animals the teeth differ remarkably in
the length and size of their different classes; and
they are separated by wider intervals : another pecu¬
liarity is the upright position of the incisors, and the
regular inclination of the whole lateral phalanx, in
8
of the teeth.
229
proportion as they are distant from the centre of
motion in the condyle of the jaw. It is indeed quite
obvious that the front teeth have a use in speech,
and therefore are different in man from those of
animals. But there is a peculiarity in the molares
also, in their obtuse tubercles, which exhibits a cor¬
respondence betwixt the teeth, taken collectively,
and the variety of food and the mixed diet which is
natural to man.
of the first set of the teeth, the milk or
deciduous teeth.
The first set of teeth are twenty in number : these
are divided into three classes ; the incisores, four in
each jaw ; the cuspidati, two in each jaw ; and the
molares, four 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
appear 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 figure exhibits a section of the lower jaw, at that period
when the milk teeth have all risen, and when the permanent teeth
are preparing in the jaw.
Q 3
230
OF THE TEETII.
The teeth do not always cut the gums in this
order; but it is the more regular and common
order. When the teeth appear in irregular succession,
more irritation and pain, and more of those symp¬
toms which are usually attributed to teething, are
said to accompany them.
The deciduous set of teeth are perfected 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,
(immutabiles), 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.
In the sixth and seventh years the jaws have so
much enlarged, 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 frequently are some of them re¬
tained 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 thought¬
lessly drawn.
of the teeth.
The jaw-bones are still so small, that the second
set of teeth must rise slowly and in succession, else
they would be crowded into too small a circle, and
of course turned from their proper direction.
The incisores of the under jaw are loose com¬
monly 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 appear. 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 re¬
taining their hold some time longer.
The anterior molares and the cuspidati falling, are
succeeded about the ninth year by the second of the
bicuspides and the cuspidati. The posterior of the
bicuspides take place of the anterior of the molares
about the tenth or eleventh year; the second per¬
manent molaris does not appear for five or six years
from the commencement of the appearance of the
permanent teeth. The jaw acquires its full propor¬
tion about the age of eighteen or twenty, when the
third molaris, or the dens sapientice, makes its ap¬
pearance. This tooth is shorter and smaller, and is
inclined more inward than the others. Its fangs are
less regular and distinct, being often squeezed to¬
gether. From the cuspidati to the last grinder, the
tangs are becoming much shorter, and from the first
incisor to the last grinder, the teeth stand less out
from the sockets and gums.
of the structure of the teeth.
A tooth consists of these parts: —The enamel (A),
a peculiarly hard layer of matter composing the sur-
q, 4
of the teeth.
face of the body of the tooth. 1 lie
internal part, or bone of the tooth (B),
is less stony and hard than the enamel,
but of a firmer structure and more com-
\f pact than common bone. In regard to
the form of the tooth, we may observe,
that it is divided into the crown, the neck, and the
fangs, or roots of the tooth, which go deep into the
jaw. There is a cavity in the body of the tooth (C),
and the tube of the fangs communicates with it.
This cavity receives 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
destruction 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 appears 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 011 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
* This section of the tooth is a plan; for in our preparations
we make the bone black by burning, to exhibit the enamel con¬
trasted with it. In this figure the bone is white, and the enamel
black.
In brutes there is a considerable variety in the relative form of
the enamel and bone of the tooth ; but it is always laid with
reference to the friction against the tooth, and so as to protect it
from the effects of attrition.
OF THE TEETH.
233
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 bone,
the phosphate of lime is deposited on the membranes,
or cartilage, but this hardening matter of bones is a
secretion from the vessels of the part, and is accu¬
mulated around the vessels themselves: it is still
within the controul of their action, and is suffering
that succession of changes peculiar to a living part.
In the enamel, the phosphate of lime has been de¬
posited 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 phosphate 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. *
* By Mr. Hatchett's Experiments, (Philos. Transact. 1799,) we
learn that bone consists of phosphate of lime, with a small pro¬
portion of carbonate of lime. The shell of the crab and lobster
consist of phosphate of lime and carbonate of lime, the latter
being in the greatest quantity. The testaceous shells consist
entirely of carbonate of lime. The matter of bone and teeth
consists of phosphate of lime and a small portion of carbonate
deposited in the interstice of an animal substance, which is of the
nature of cartilage, and proves to be gelatine. The bones of fish
differ from those of man 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 deposition, or are still under the influence of the circulating
vessels, whether they possess a principle of self-preservation
independent of vascularity, or are like common dead matter
altogether out of the system.
The formation of bone has been very fully described. The
formation of shell is more like that of teeth. The testaceous shell
consists of layers ; the layers are formed successively by secretion
i from the animal body, and each successive layer is broader than
i the preceding, answering to the increased circumference of the
animal. Reaumur broke the shell of a snail, and he found that
when he covered the surface of the creature and pi evented the
exudation, no shell was formed.
234
OF THE TEETH.
Although we call the earthy deposit the harden¬
ing matter, yet it is the union of the glutinous matter
which bestows the extreme hardness ; for, when the
tooth is as yet within the jaw, and in an early stage
of its formation, the deposition is soft, and its sur¬
face rough ; but, by a change of action in the
secreting surface, which throws out this fluid, the
first deposition is penetrated with a secretion, which
either by this penetration simply, or by causing a
new apposition of its parts, (its structure, indeed,
looks like crystallization,) bestows the density and
extreme hardness on the crust or enamel.
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 pro¬
cess of feeding, the enamel 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 covered with a black vitreous
matter, and sometimes they have a crust of a shining
substance like bronze. In the grinding teeth of the
graminivorous animals, the arrangement of the ena¬
mel is quite peculiar.
From the composition of the enamel, we must be
aware of the bad 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.
OF THE CENTRAL BONY PART OF THE TOOTH.
The chemical composition, and the manner ot
combination of the matter forming the central part
of the tooth, and of the fangs, is similar to other
10
OF THE TEETH.
235
bones of the body; but when we examine the hard¬
ness and the density of the tooth, and see that it is
not even porous, or apparently capable of giving
passage to vessels, we conclude that it is not vas¬
cular, and are apt to suppose that it holds its con¬
nection 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
covered with a periosteum like other bones. The
vascularity of the periosteum, which surrounds the
tooth, and the vessels which enter by the fangs to
the cavity of the tooth, seem to be a provision 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 circu¬
lating through the body of the tooth, and that the
tooth undergoes 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 experi¬
ment affording a fair proof that the circulation con¬
tinues 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 matter. They become yellow, trans¬
parent, 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
236
OF THE TEETH.
alleged in proof of their vascularity ; not only the
pressure of the rising tooth on the fangs ot the tem¬
porary teeth will cause an absorption of the latter,
but the fangs of the temporary teeth will waste and
be absorbed, so as to drop out without the mecha¬
nical pressure of the permanent teeth, and before
they have advanced to be-in contact with the former.
Of what nature is this absorption of the fangs of the
deciduous teeth? Is it an influence commencing
in the tooth, or is it the agency of the vascular
substance around the tooth ?
The teeth seem acutely sensible; but a little con¬
sideration teaches us that the hard substance of the
teeth is not endowed with sensibility, and that it
must be the remains of the vascular pulp, presently
to be described, occupying the centre of the tooth,
which being supplied with nerves, gives the acute
pain in tooth-ach. It is as a medium communi¬
cating or abstracting heat, that the condition of the
tooth is attended with pain. When wrought upon
by the dentist's file, no sensation is produced unless
the tremor be communicated to the centre, or unless
the 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
whicli 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
inflame the central periosteum and marrow. The
OF THE TEETH.
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 dis¬
coloured 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, however, some say, may be owing to the mere
compactness of the ossific depositions.
In the further consideration of this subject, there
are circumstances which will make us conclude that
there is no vascular action in the teeth, and incline
us to believe that they possess a low degree of life,
independent of vascular action. Supposing the bony
part of the tooth to be vascular, and to possess the
principle of life, is not the firm adhesion and con¬
tact 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 com¬
mon effects of excitement and exfoliation or inflam¬
mation in the latter.
In rickets, and mollities ossium, and other diseases
of debility in which the body 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 diseases, are pro¬
duced by the activity of the absorbents prevailing
over the action of the red vessels ; while in the teeth
no such effect can take place, if they are formed
by a deposition of bony matter which is not re-ab¬
sorbed, nor subject to the revolution of deposition
and re-absorption, which takes place in other parts
of the body. Accordingly we find in rickets, where
the hardest bone yields, and where the jaw-bone
itself is distorted or altered in its form by the actions
of its muscles, that the teeth remain distinguished
for their size and beauty. In mollities ossium I
have found the teeth loose, but hard in their sub¬
stance. In rickets the teeth are large, and perfectly
238
OF THE TEETH.
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 deficient in form, or the crust of enamel
which covers them is irregular, and which circum¬
stances continue through life; instances of this my
reader may see in my Collection.
When.an adult tooth of one jaw is lost, there ap¬
pears 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 consequence of the want of that
pressure to which it is naturally accommodated. The
teeth of the rodentia are wasted by attrition, and
seem to grow. This is, indeed, a growth, but it is
of the nature of the first formation of the tooth pro¬
ceeding from the pulp * ; for while the tooth wastes
by attrition on its anterior edge, it continues to grow
by addition from the pulp, and to be pushed for¬
wards.
Much has been said of balls being found in ele¬
phants' teeth, as they are found in bones, the bony
matter accumulated around the ball, and considered
to be 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 after it has pierced the shell of the tooth.
The roots of the teeth are sometimes found en¬
larged, distorted, or with exostosis formed upon
them. Again, the cavity 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
* See the ingenious Inaugural Dissertation of Dr. Blake.
of the teeth.
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 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 conse¬
quence of which it has lost its sympathy with the
surrounding living parts, and becomes a source of
irritation like a foreign body.
The transplanting of teeth presents another very
interesting phenomenon. A tooth recently drawn,
and placed accurately into a socket from which one
has been taken, will adhere 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 reaction and disease
in them. No doubt sometimes very distressing effects
are produced by these operations, as tetanus, abscess
in the jaws, &c.; but this happens in consequence of
the central nerve being bruised by the wedging 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 sur¬
rounded by the gums, a red, vascular, but firm sub¬
stance, 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;
240
OF THE TEETH.
and by mastication, when the teeth are lost, they
gain a degree of hardness which proves almost a sub¬
stitute 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 of bony contact. Like the alveolar process, the
gums have a secret connection with the state of the
teeth. Before the milk-teeth appear, there is a firm
ridge which runs along the gums, but this is thrown
off, or wastes with the rising of the teeth : and as the
teeth rise, the proper gums grow, and embrace them
firmly. The gum is firm, and in close adhesion, when
the teeth are healthy; loose, spongy, or shrunk,
when they are diseased. The only means of oper¬
ating upon the general state of the teeth is through
the gums; 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 sub¬
ject to frequent bleeding, (which is improperly called
a scorbutic state,) the teeth become loose, and the
gums too sensible. 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 absorption of the
socket.
We must conclude, that the whole of the phe¬
nomena displayed in the formation, adhesion, and
diseases of the teeth, show them to be possessed of
life, and that they have a correspondence or sym¬
pathy with the surrounding parts. But are we pre¬
pared 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?
In answer to this, there are not wanting examples of
an obscure and low degree of life existing in animals,
ova, or seeds, for seasons, without a circulation; and
if for seasons, why not for a term of life ? We never
observe the animal economy providing superfluously;
op the teeth.
241
and since there is no instance to be observed in which
the teetli have shown a power of renovation, why
should they be possessed of vascularity and action
to no useful purpose ? All that seems necessary to
them is, that they should firmly adhere without
acting as a foreign and extraneous body to the sur¬
rounding parts ; and this, vitality, without vascular
action, seems calculated to provide.
of the formation and growth of the teeth.
this figure we see the milk-teeth of one side
their membraneous sacs. The first of the permanent
teeth is also seen in a state of advancement.
In the jaws of a child newly born, there are con¬
tained two sets of teeth as it were in embryo ; the
deciduous, temporary, or milk-teeth ; and the per¬
manent teeth. The necessity for this double set of
teeth evidently is to be found in the incapacity of
alteration of shape or size in the teeth, as in other
parts of the body ; the smaller teeth, which rise first,
and are adapted to the curve and size of the jaw-bone
of an infant, require to be succeeded by others,
larger, stronger, and carry¬
ing 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 connected with it. A is the
sac containing the milk-tooth : L the sac of the pei-
manent tooth attached to the sac of the milk-tooth,
vol. r.
OF THE TEETIl.
When we open one of these sacs at an early period
of the formation of the tooth, a very curious appear¬
ance presents itself: a little shell of bone is seen
within the sac, but no enamel 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 sub¬
stance of the tooth, a soft vascular stool, or pulp*,
is found to have been the mould on which this outer
layer of ossific matter has been formed ; and a further
observation will lead us to conclude, that this bony
part of the tooth is in the progress of being formed
by successive layers of matter thrown out from the
surface of this vascular pulp ; though many have
t explained the formation of the tooth, by
supposing that the layers of this pulp
were successively ossified. A is the pulp
on which the tooth is formed : B the
sac opened, which surrounds the pulp
and new tooth, and which secretes the
enamel: C the shell of the new tooth
taken off the pulp A, to which of course
it corresponds accurately in shape.
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, or rather secretion of ossific matter, but,
as the period of revolution advances, where it forms
the rudiments of the molares for example, its base
splits so as to form the mould of two, three, or four
fangs, or roots ; for around these divisions of the
pulp the ossific matter is thrown out so as to form a
tube, continued downwards from the body of the
tooth. Gradually, and by successive layers of matter
on the inside of this tube, it becomes a strong root,
* Le noyau, la coque, or ]e germe de ia dent, by the French
authors.
OF THE TEETH.
243
or tang, 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
into this narrow space.
We have said that the tooth forming on its pulp,
or vascular bed, is surrounded with a membrane,
giving the whole the appearance of a little sac. This
membrane has also an important use. It is vascular
also, as the pulp is, but it is more connected with the
gums, and receives its vessels from the surface, while
the pulp, lying under the shell of the tooth, receives
its blood-vessels from that branch of the internal
maxillary artery which takes its course in the jaw.
The enamel is formed after the body of the tooth
has considerably advanced towards its perfect form.
It is formed by a secretion from the capsule, or
membrane, which invests the teeth*, 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 point and body of the tooth would
be covered with a thicker deposition ; but it rather
appears that that part of the sac opposite 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
explanation of the manner in which the enamel is
formed. He describes 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
* This outer sac has been called chorion, from the numerous
vessels distributed upon it.
R 2
OF THE TEETH.
will perceive it to be composed of little vesicles in
regular order, and which sometimes have a limpid
fluid contained in them. This liquid exuded upon
the surface of the teeth he supposes to form the
enamel. He explains also how this sac, originally
investing the body and neck of the tooth, being-
pierced by the edge of the tooth, and the tooth
rising through it, is inverted, and by still keeping
its connection with the circle of the crown of the
tooth, rises up in connection with the gum, and in
some degree forms the new gum which surrounds
the tooth.
The sac which encloses the rudiments of the tooth
consists of a double membrane. The outer mem¬
brane 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 synovia in the
joints, between this membrane and the pulp of the
tooth. I do not imagine that the enamel is pro¬
duced 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 changes
the nature of its action, when the bone of the tooth
is perfected in its outer layer, and that it then
throws out the matter which consolidates into
enamel.
This subject of the formation of teeth would be
incomplete if we left unexplained the peculiar struc¬
ture of the teeth of graminivorous animals.
Mr. Corse, in a curious paper in the Philosophical
Transactions of London for the year 1799, 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 laminee or teeth, each covered with
its proper enamel; and that these teeth are merely
joined to each other by an intermediate softer sub¬
stance, acting like cement.
The structure of the grinders, even from the first
glance, must appear very curious, being composed
7
OF THE TEETH.
245
of a number of perpendicular laminae, 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 masti¬
cation of the food; and, in a few months after some
of these teeth cut the gum, the enamel remains con¬
siderably higher, so that the surface of each grinder
soon acquires a ribbed appearance, as if originally
formed with ridges.
The pulp of graminivorous animals is not shaped
like that which forms the human tooth ; it consists
of several processes united at their base. The cap¬
sule 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 capsule,
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 pro¬
cesses have deposited on them the enamel. The
membraneous 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 con¬
tinued attrition necessary in the grinding and rumi¬
nation of the herbivorous and graminivorous animals.
The grinding teeth of the purely carnivorous animals,
* See a paper of Sir E. Home's in the Philosophical Transac¬
tions, and Dr. Blake's Inaugural Dissertation.
u 3
246
OF THE TEETH.
as of the lion and tiger, close like the blades oi
scissars: they are prevented by the long canine
teeth from moving laterally ; and as they are not
subject to attrition, the enamel only covers their
surfaces.
OF THE GROWTH OF THE SECOND SET OF TEETH,
AND THE SHEDDING OF THE FIRST.
The teeth of the first or deciduous set are twenty
in number. They are small, being adapted for the
jaws of a child; they are destined to be shed, and
to give place to the adult or permanent set of teeth.
Accordingly, in observing the progress of the forma¬
tion of this first set of teeth, the rudiments of the
second may also be seen so early as in the foetus of
the seventh or eighth month ; and in the fifth and
. sixth month after birth, the ossification begins in
them. The rudiment of the permanent tooth may
be observed even when the sac which contains it is
very small, and appears like a filament stretching up
to the neck of the sac of the deciduous tooth. *
These sacs lie on the inner side of the jaw-bone, and
when further advanced, the necks of the two sacs
(both as yet under the gum) are united; but when
the first teeth are fully formed, and have risen above
the gum, the alveolar processes have been at the
same time formed around them, and now the sacs of
the permanent teeth have a connection with the gums
through a small foramen in the jaw-bone, behind the
space through which the first teeth have risen.
The opinion entertained, that the second set of
teeth push out the first, is erroneous, for the change
on the deciduous and the growing teeth seems to be
influenced 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 suppose that the newly formed tooth should
* See the two figures in page 211.
OF THE TEETH.
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 vascu¬
larity, 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 effected by similar laws ; that at a par¬
ticular 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 ten¬
dency to dissolution independently of a circulation
of blood through it ? and as the roots waste, do the
surrounding vascular parts absorb its substance ? or,
does the surrounding vascular 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
destroyed^ it does not waste : when teeth are pivoted,
their roots remain twenty years without wasting or
being absorbed ; and when the vascular centre of the
milk-teeth is destroyed, their roots waste no more,
and they continue adhering to the gum. This seems
to point to the internal membrane of the tooth as
the means of its absorption.
It is no proof of the first set being pushed out by
the second set of teeth, that if the permanent teeth
do not rise, the first will remain, their roots unwasted
and firm, even to old age ; for still I contend, that
there is an agreement and coincidence betwixt the
r 4
248
OF THE TEETH.
two sets of teeth in their changes, and also in the
alveoli by which they are surrounded ; but this is
not produced 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 happen;
it will in general fall out.
The old and the new teeth are lodged in distinct
compartments of the jaw-bone, and, what is more
curious, their alveoli are distinct; for as the roots
of the first teeth decay, their alveolar processes are
absorbed, while again, as the new teeth rise from
their deep seat in the jaw-bone, they are accom¬
panied 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 a proof of the con¬
tinual growth of teeth. But there is a fallacy in the
observation ; 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. For this reason they get an
inclined direction; and this inclination may be
observed in several of the adjoining teeth.
No circumstance can better illustrate how perfect
the dependence of the alveoli is upon the teeth, than
that of their being thrown off with them in extensive
exfoliations. I have a specimen of this in my Col-
OF THE TEETH.
lection, where the whole circle of the alveolar pro¬
cesses and teeth is thrown off. This happened after
the confluent small-pox. I think I recollect a similar
case occurring 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.
250
OF THE MUSCLES.
THEIR TEXTURE, AND THE VARIETIES IN THE
ARRANGEMENT OF THEIR FIBRES.
The muscles are the appropriate organs of motion.
They are distinguished by their peculiar texture,
and by their singular vital property of contraction.*
The muscle is the only proper fibrous texture in
the human frame. These fibres have the power of
contracting, and are the active agents, in contradis¬
tinction to the bones and tendons, and ligaments,
which are passive instruments under the influence of
the muscles. The muscular fibres are formed into
packets, or fasciculi: these fasciculi are variously
ordered or arranged in the several muscles, and
adapted to the action to be performed.
The proper muscular fibres are everywhere en¬
veloped by the common cellular substance. Towards
the extremities of the muscle, the proper fibres
become fewer, and begin successively to terminate;
by which the cellular membrane, being free from the
interposition of the fibres, the divisions of it approach,
and become more firmly combined, so as to form a
tendon or rope. This tendon holds relation to each
fibre of the proper muscle; and when these fibres
contract, they concentrate and unite their power
upon the tendon. The tendons, then, are not the
continuations of the fibres of the proper muscle, but
of the interstitial cellular membrane.
* At the end of the history of the muscles, the subject of
muscular power is treated of.
OF THE MUSCLES.
251
Every muscle is supplied with arteries, veins, lym¬
phatics, and nerves. Without nerves they would be
insulated parts, contracting perhaps spasmodically and
irregularly ; but through the nerves these contrac¬
tions are regulated so as to be efficient in the economy
of the system, or the motions of the body.
The muscles are divided into simple and com¬
pound ; the simple muscles are those which have
their fibres in a similar direction and disposition.
The most common being the ventriform, so called
because the middle is large, and they diminish gra¬
dually towards their tendons or extremities.
I have given here the example of the ventriform
muscle in the biceps, which, as it has two heads
or tendinous origins running into one belly, is so
named. Another simple muscle is when the fibres
are laid flat and parallel: these do not terminate in
a round tendon, but in a broad web of the same
material. The muscles are radiated; that is, their
fibres are laid diverging, or like the radii of a cir-
cle. This is the
pectoralis major,
which is an ex-
ample of the
~ S; fibres converg-
ing to their ten-
dinous insertion.
Or they are pen-
niform ; that is,
resembling the feathers of a quill, the fibres running
parallel, but all of them oblique to their tendons.
There is a double penniform muscle, which, indeed,
is the form most like a quill or feather ; for a double
range of parallel fibres are obliquely insei icd 01
attached to the tendon, the tendon running up
252
OF THE MUSCLES.
betwixt them. There are muscles which are called
complicated, from their having two or more tendons,
and a variety in the insertion of oblique fibres into
these tendons. From the different disposition of the
fibres results the absolute force of the muscles ; but
the mode of the attachment, or, as it is termed, the
insertion of their tendons, determines their real
effect.
The muscles accomplish very different purposes.
Their first, or most important purpose, is to move
the fluids through the intestines and hollow tubes,
thus performing the motions necessary to the vital
functions.* Besides these, they conform themselves,
commonly, to the apparatus of the frame. 1. They
envelope and compress, and sustain the viscera, as
the abdominal muscles. 2. They lengthen, shorten,
or compress some organ, as the tongue. 3. They
widen or contract some aperture, as the sphincter
muscles. 4. They relax, or draw up, or render rigid
some valve, or septum, or curtain, as the velum of
the palate. 5. They roll or move, and are thus sub¬
servient to the organs of the senses, as the eye and
ear. 6. They are inserted or attached to the bones,
and thus perform the voluntary motions. It is prin¬
cipally in this last office that we have now to study
them. The human body is estimated to have 436
muscles, differing, however, in the sexes, and accord¬
ing to individual peculiarities. In these examples,
with little exception, the fibres run obliquely to their
insertions; by which they lose force, but gain velo¬
city, in the motion communicated to their point of
insertion.
A muscle is fibrous, that is, it consists of minute
threads bundled together, the extremities of which
are connected with the tendons which have been de¬
scribed. Innumerable fibres are thus joined together
to form one muscle, and every muscle is a distinct
organ. Of these distinct muscles for the motions of
* They embrace and contract on the hollow viscera, a? the
bladder and uterus.
OF THE MUSCLES.
253
the body there are not less than 436 in the human
frame, independent of those which perform the in¬
ternal vital motions. The contractile power, which
is in the living muscular fibre, presents appearances
which, though familiar, are really the most surprising
of all the properties of life. Many attempts have
been made to explain this property, sometimes by
chemical experiment, sometimes on mechanical prin¬
ciples, but always in a manner repugnant to common
sense. We must be satisfied with saying, that it is
an endowment, the cause of which it would be as
vain to investigate as to resume the search into the
cause of gravitation.
The ignorance of the cause of muscular contraction
does not prevent us from studying the laws which
regulate it, and under this head are included subjects
of the highest interest; which, however, we must
leave, to pursue the mechanical arrangement of the
muscles.
Since we have seen that there are so many
muscles in the body, it is due to our readers to
explain how they are associated to effect that com¬
bination which is necessary to the motion of the
limbs and to our perfect enjoyment. In the first
place, the million of fibres, which constitute a single
muscle, are connected by a tissue of nerves, which
produce a union or sympathy amongst them, so that
one impulse causes a simultaneous effort of all the
fibres attached to the same tendon. When we have
understood that the muscles are distinct organs of
motion, we perceive that they must be classed and
associated, in order that many shall combine in one
act; and that others, their opponents, shall be put in
a state to relax, and offer no opposition to those
which are active. These relations can only be
established through nerves, which are the organs of
communication with the brain, or sensorium. The
nerves convey the will to the muscles^ and at the
same time they class and arrange them so as to
make them consent to the motions of the body and
limbs.
254
OF THE MUSCLES.
On looking to the manner in which the muscles
are fixed into the bones, and the course of their
tendons, we observe everywhere the appearance of
a sacrifice of mechanical power, the tendon being
inserted into the bone in such a manner as to lose
the advantage of the lever. This appears to be an
imperfection, until we learn that there is an accumu¬
lation of vital power in the muscle in order to attain
velocity of movement in the member.
The muscle D, which bends the fore-arm, is in¬
serted into the radius E, so near the fulcrum, or
centre of motion in the elbow joint, and so obliquely,
that it must raise the hand and fore-arm with dis¬
advantage. But, correctly speaking, the power of
the muscle is not sacrificed, since it gains more than
an equivalent in the rapid and lively motions of the
hand and fingers, and since these rapid motions are
necessary to us in a thousand familiar actions ; and
to attain this, the Creator has given sufficient vital
power to the muscles to admit of the sacrifice of the
mechanical or lever power, and so to provide for
every degree and variety of motion which may
answer to the capacities of the mind.
If we represent the bones and muscles of the fore¬
arm by this diagram, we shall see that power is lost
by the inclination of the tendon to the lever, into
which it is inserted. It represents the lever of
the third kind, where the moving power operates on
a point nearer the fulcrum than the weight to be
moved.
9
OF THE MUSCLES.
<255
Here A represents the
B
muscle, B the lever, and
C the fulcrum. The
power of the muscle is
not represented by the
distance of its insertion
a-> from the fulcrum C. The line which truly repre¬
sents the lever must pass from the centre of motion,
perpendicularly to the line of the tendon, viz., C b.
Here, again, by the direction of the tendon, as well
as by its actual attachment to the bone, power is
lost and velocity gained.
We may compare the muscular power to the weight
which impels a machine. In studying machinery, it
is manifest that weight and velocity are equivalent.
The handle of the winch in a crane is a lever, and
the space through which it moves, in comparison
with the slow motion of the weight, is the measure
of its power. If the weight, raised by the crane,
be permitted to go down, the wheels revolve, and
the handle moves with the velocity of a cannon-ball,
and will be as destructive if it hit the workman.
The weight here is the power, but it operates with
so much disadvantage, that the hand upon the handle
of the winch can stop it: but give it way, let the
accelerated motion take place, and the hand would
be shattered which touched it. Just so the fly¬
wheel, moving at first slowly, and an impediment to
the working of a machine, at length acquires mo¬
mentum, so as to concentrate the power of the
machine, and enable it to cut bars of iron with a
stroke.
The principle holds in the animal machinery. The
elbow is bent with a certain loss of mechanical power ;
but by that very means, when the loss is supplied
by the living muscular power, the hand descends
through a greater space, moves quicker, with a
velocity which enables us to strike or to cut. With¬
out this acquired velocity, we could not drive a nail:
the mere muscular power would be insufficient for
many actions quite necessary to our existence.
256 THE MUSCLES.
Let us take some ex¬
amples to show what objects
are attained through the ob¬
lique direction of the fibres
of the muscle, and we shall
see that here, as well as by
the mode of attachment of
the entire muscle, velocity
is attained by the sacrifice
of power. Suppose these
two pieces of wood are to be drawn together by
means of a cord, but that the hands which pull,
although possessing abundant strength, want room
to recede more than what is equal to one third of the
space betwixt the pieces of wood; it is quite clear, that
if the hand were to draw directly on a cord between
A and B, the point A would be brought towards
B, through one third only of the intervening space,
and the end would not be accomplished. But if
the cord were put over the ends of the upper piece,
as E D, and, consequently, directed obliquely to
their attachment at A, 011 drawing the hand back a
very little, but with more force, the lower piece of
wood would be suddenly drawn up to the higher
piece, and the object attained. Or we may put it in
this form: —If a muscle contract in the direction of
its tendon, the motion of the extremity of the tendon
will be the same with that of the muscle itself: but
if the attachment of the muscle to the tendon be
oblique, it will draw the tendon through a greater
space; and if the direction of the muscle deviate so
far from the line of the tendon as to be perpendicular
to it, it will then be in a condition to draw the
tendon through the greatest space with the least con¬
traction of its own length.
r t ~i D a muscle ; by the contraction of
V J C to D the extremities of the tendon
A B will be brought together, through
a space double the contraction of the
muscle. It is the adjustment, on the same principle,
Thus, if A B be a tendon, and C
of the muscles.
which gives the arrow so quick an impulse from the
spring of the bow, the extremities of the bow draw¬
ing obliquely on the string.
1 o free breathing, it is necessary that the ribs
shall approach each other, and this is performed
by certain intercostal muscles, (or muscles playing
between the ribs ;) and now we can answer the
question, why are the fibres of these muscles oblique ?
Let us suppose this
figure to represent two
ribs with thin inter¬
vening muscles. If
the fibres of the muscle
were in the direction
A, across and perpendicular to the ribs ; and if they
were to contract one third of their length, they would
not close the intervening space — they would not
accomplish the purpose. JBut being oblique, as at
B, although they contract no more than one third of
their length, they will bring the ribs C D together.
By this obliquity of the intercostal muscles, they are
enabled to expand the chest in inspiration, in a man¬
ner which could not be otherwise accomplished.
However, let the reader understand that, in respect
to the motions of respiration, we are stating the
action of these fibres in the simplest mode. Had we
to explain here the expansion of the ribs in inspi¬
ration, it would be necessary to consider the attach¬
ments of the ribs as counteracting forces.
In the greater number of muscles the same prin¬
ciple directs the arrangement of the fibres ; they
exchange power for velocity of movement, by their
obliquity. They do not go direct from origin to in¬
sertion, but obliquely, thus, from tendon to tendon:—
Supposing the point
A to be the fixed point,
these fibres draw the
point B with less force,
but through a larger space, or more quickly than if
they took their course in direct lines ; and by this
arrangement of the fibres the freedom and extent of
motion in our limbs are secured.
vol. i. s
258
OF THE MUSCLES.
But the muscles must be strengthened by addi¬
tional courses of fibres, because they are oblique;
since by their obliquity they lose somewhat of their
force of action : and therefore it is, we must presume,
that we find them in a double row, making what is
termed the penniform muscle, thus, —
which permit additional series of fibres; and all
this for the obvious purpose of accumulating
power, which may be exchanged for velocity of
movement.
We may perceive the same effect to result from
the course of the tendons, and their confinement in
sheaths, strengthened by cross-straps of ligament.
If the tendon A took the shortest course to its
termination at B, it would draw up the toe with
greater force; but then the toe would lose its
velocity of movement. By taking the direction C
close to the joints, the velocity of motion is secured,
and by this arrangement the toes possess their spring,
and the fingers their lively movements.
We may take this opportunity of noticing how the
mechanical opposition is diminished as the living
muscular pow er is exhausted. For example, in lifting
a weight, the length of the lever of resistance will be
from the centre of the elbow joint, A, to the centre
and sometimes the
texture of the muscle
|gi is still further com¬
pounded by the inter¬
mixture of tendons,
10
OF THE MUSCLES.
259
of the weight, B. As the muscles of the arm con¬
tract, they lose something of their power; but in a
greater proportion is the mechanical resistance dimi¬
nished, for when the weight is raised to C, then A D
becomes the measure of the lever of resistance.
rising or falling, is carried beyond the sphere of
action of one class of muscles, and enters the sphere
of activity of others. And this adaptation of the
organs of motion is finely adjusted to the mechanical
resistance which may arise from the form or motion
of the bones. In short, whether we contemplate the
million of fibres which constitute one muscle, or the
many muscles which combine to the movement of
the limb, nothing is more surprising and admirable
than the adjustment of their power so as to balance
mechanical resistance, arising from the change of
position of the levers.
In the animal body, there is a perfect relation
preserved betwixt the parts of the same organ. The
muscular fibres forming what is termed the belly of
the muscle, and the tendon through which the muscle
pulls, are two parts of one organ ; and the condition
of the tendon indicates the state of the muscle.
s :2
OF THE MUSCLES.
Thus jockies discover the qualities of a horse by its
sinews or tendons. The most approved form in the
leg of the hunter, or hackney, is that in which three
convexities can be distinguished, — the bone ; the
prominence of the elastic ligament behind the bone ;
and behind that the flexor tendons, large, round, and
strong. Strong tendons are provided for strong
muscles, and the size of these indicate the muscular
strength. Such muscles, being powerful flexors,
cause high and round action, and such horses are
safe to ride ; their feet are generally preserved good,
owing to the pressure they sustain from their high
action. But this excellence in a horse will not make
him a favourite at Newmarket. The circular motion
cannot be the swiftest; a blood-horse carries his
foot near the ground. The speed of a horse depends
on the strength of his loins and hind quarter; and
what is required in the fore-legs is strength of the
extensor tendons, so that the feet may be well thrown
out before, for if these tendons be not strong, the
joints will be unable to sustain the weight of his
body, when powerfully thrown forward, by the
exertion of his hind-quarters, and he will be apt to
come with his nose to the ground.
The whole apparatus of bones and joints being
thus originally constituted by Nature in accurate
relation to the muscular powers, we have next to
observe, that this apparatus is preserved perfect by
exercise. The tendons, the sheaths in which they
run, the cross ligaments by which they are restrained,
and the bursa3 mucosa?*, which are interposed to dimi¬
nish friction, can be seen in perfection only when
the animal machinery has been kept in full activity.
In inflammation, and pain, and necessary restraint,
they become weak ; and even confinement, and want
of exercise, without disease, will produce imperfec¬
tions. Exercise unfolds the muscular system, pro¬
ducing a full bold outline of the limbs, at the same
* These bursts mucosae (mucous purses) are sacs containing a
lubricating fluid. They are interposed wherever there is much
pressure or friction, and answer all the purposes of friction-
wheels in machinery.
of the muscles.
time that the joints are knit, small, and clean. In
the loins, thighs, and legs of a dancer we see the
muscular system fully developed ; and when we turn
our attention to his puny and disproportioned arms,
we acknowledge the cause — that, in the one in¬
stance, exercise has produced perfection, and that,
in the other, the want of it has occasioned deformity.
Look to the legs of a poor Irishman travelling to the
harvest with bare feet: the thickness and roundness
of the calf show that the foot and toes are free to
permit the exercise of the muscles of the leg. Look,
again, to the leg of our English peasant, whose foot
and ankle are tightly laced in a shoe with a wooden
sole, and you will perceive, from the manner in which
he lifts his legs, that the play of the ankle, foot, and
toes is lost, as much as if he went on stilts, and,
therefore, are his legs small and shapeless.
For the purpose of dissection, it is as necessary to
understand the varieties in the forms of the tendons
as of the muscles. The tendons are textures of
great strength and firmness, which are intermediate
betwixt the irritable fibres, forming a muscle, and
the points of attachment. The ligaments are of the
same texture, but they want this part of the defini¬
tion ; they are stretched from one fixed point to
another, not intermediate betwixt muscular fibres
and bone.
Very often the tendon of a muscle assumes a round
form, and resembles a rope ; but they are also of a
flat form, or extended into a web, or they are
radiated, and spreading in digitations. It is difficult
actually to distinguish the expanded tendons from
the fasciie and aponeuroses, which are sheets of a
tendinous intertexture, to which very often muscles
are attached, but which have other offices, besides
affording attachment of muscles.
The fasciae cover and embrace the limbs like
bandages. Their under surfaces have, generally,
divisions and subdivisions, which sink down betwixt
the muscles, and serve to class them, and sometimes
to direct their action, and to hold them as in a
sheath. The aponeurosis is a term somewhat loosely
s 3
262
muscles of the
applied: we shall consider it as expressive of those
sheets of tendinous texture, which are continued
from the tendons or ligaments, without fairly em¬
bracing the limb. They differ in density and firm¬
ness from the shining, silvery, expanded tendon, to
the layer of the common, soft, cellular texture.
Another variety of the tendon, or ligament, is the
ring of firm ligamentous substance, which is in the
neighbourhood of the joints, and which ties down
the tendons, which would otherwise start from their
places : and which, furnishing sheaths to the tendons,
directs their course, and, as it were, appropriates the
action of the muscle.
See further of these subjects under the title of the
cellular substance.
OF THE MUSCLES OF THE FACE, EYE,
AND EAR.
muscles of the face.
occipito- I. The occipito-frontalis is a broad and thin
frontalis. muscular expansion, whicli covers all the upper part
of the cranium. It consists of two bellies, with an
intermediate sheet of flat tendon. The one bellv
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 distinct muscles, viz. the occipital
and frontal, while others (because of a sort of
rapha, or line of division in the middle of each belly,)
have described four muscles, viz. two frontal, and
two occipital muscles. But it is truly a double-
bellied muscle; and the broad thin tendon, which
belongs equally to both bellies, lies above the true
pericranium, and slides upon it. The muscle is
therefore named, with strict propriety, occipito-fron¬
talis, sometimes epicranius, sometimes biventer, or
digastricus capitis.
face, eye, and ear.
263
Origin. — The occipital portion is the fixed point Or. sup.
of this muscle, arising from the superior transverse ridjJTS^e
ridge of the occipital bone, and covering the back occipitai
part of the head, from the mastoid process of one Jvem'back
side, round to that on the opposite side of the head. Partofthe
And by the perpendicular ridge of the occiput, it is p^oftem-
marked with a slight division in the middle. poraibone.
Insertion. — The fore belly of the muscle which 1# In. orbi
covers the forehead is fixed more into the skin and cularis pal-
eye-brows than into the bone : it is slightly attached ofthe'eye-
to the bone, near the inner end of the orbitary ridge, brow-
and especially about the inner corner of the eye, nkryTfdge";
and the root of the nose, by a smaller and acute s-by a p¬
pointed process called the descending slip of the IhelLSn!0
occipito-frontalis ; but still its chief attachment is to ans pr°-
the skin under the eye-brows.
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.
I consider the occipital belly as the fixed point,
having a firm origin from the ridge of the bone ; its
frontal belly has the loose end attached, not to the
os frontis, but to the eye-brow and skin, and its
office, that of raising the eye-brows, wrinkling the
forehead, and corrugating the whole of the hairy
scalp. It is a muscle expressive of passion, and it
is sometimes so thin as hardly to be perceived.
There is a small, neat, and pointed slip of the Descend-
occipito-frontalis, which goes down with a peak inssllp-
towards the nose, and is inserted into the small nasal
bone. This process being much below the end of
the eye-brow, must pull it downwards; so that
while the great muscle raises the eye-brow and skin
of the forehead, this small nasal slip pulls the eye-brow
downwards again, restoring it to its place, and
smoothing the skin.
s 4
264
muscles of the
Or. intern.
angu!ar
process.
In. skin of
the eye¬
brow.
Orbicularis
oculi.
Or. orbit-
ary pro. of
the sup.
maxillary
bone.
Jii. tlie
same.
Musculus
ciliaris.
II. The corrugator supercilii is a small muscle
which lies along the upper margin of the orbit, under
the last. Its origin is from the internal angular pro¬
cess of the frontal bone. Thence it runs outward,
and a little upward, to be inserted into the skin
under the eye-brow. Its action is to knit and
corrugate the eye-brows.
III. Orbicularis palpebrarum is a neat and
regular muscle, surrounding the eye, and covering
the eye-lids in a circular form. It should be con¬
sidered as two muscles, for there are a set of pale
fibres running on the eye-lids, which move in the
rapid and involuntary motion of the eye-lids. There
are other stronger and redder fibres, which run
round the orbit, and these are only used in passion,
or in spasmodic closing of the eye-lids, as when
something irritates the organ, and forces out the
tears. 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 return in a circular
form round by the lower eye-lid to the point from
whence they had set out. 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 crossing as a meeting of fibres
from the upper and from the lower muscle, have
described it as two semicircular 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 opinion, that it is a circular
face, eye, and ear.
c>6f)
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 vio¬
lence, 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 palpebr^e superioris.—This small levator
muscle arises deep within the socket, from the margin superiors,
of that hole which gives passage to the optic nerve.
It begins by a small flat tendon in the bottom of the Or. upper
optic cavity, becomes gradually broader as it goes ^ of
over the eye-ball ; it ends in the eye-lid, by a broad foramen
expansion of muscular fibres, which finally terminate optlcum-
in a short flat tendon. It lies under the orbicularis In• whoIe
palpebras, is inserted into the whole length of the superior ci-
cartilage of the tarsus, and raises and opens the upper liarycarti-
eye-lid. lage'
The occipito-frontalis, but especially its occipital Action of
belly, raises the eye-brows; the pointed slip of the cieT mus
same muscle pulls them downwards ; the corrugator
pulls them directly inwards, and knits the brows : the
levator palpebrae opens the eye-lid, and the orbi¬
cularis oculi closes the eye. Whether certain fibres
from the platysma-myoides (a thin flat muscle which
mounts from the neck over the cheek) may not pull
down the lower eye-lid, or whether some straggling
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 regu¬
larly-appointed muscle, and the lower eye-lid is not
directly moved, at least in man.*
muscles of the nose and mouth.
V. Levator labii superioris and al^: nasi.— Levator
Cowper describes the levator labii superioris as an
irregular production of the frontalis, extending along que nasi,
the nostrils. But it is a neat and delicate muscle,
which arises, by a small double tendon, from the
# See of the motions of the eye, vol. iii.
266
MUSCLES OF THE
Or. Nasal nasal process of the upper jaw-bone, close by the
m^x °bone tendon of the orbicularis oculi. It is one little fasci-
max. one. q£ muscuiar fibres above ; but as it approaches
the nose, it spreads out broader, dividing into two
small fasciculi, one of which is implanted into the
wing or cartilage of the nose, and the other, passing
in. upper the angle of the nose, goes to the upper lip : thus
nasfnd ala ^ is pyramidal with its base downwards, and was
named pyramidalis 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.
Levator VI. The LEVATOR LABII SUPERIORIS PROPRIUS is
oHslpro-rl" distinguished by the name of levator prop ri us, because
prius. there are two others ; one belonging to the angle of
the mouth, and consequently to both lips ; and one
common to the lip and nostril.
Or. Orbit. The levator proprius is often named musculus inci-
max°bSUp' siyus> because it arises from the upper jaw, just above
below the the incisores, or cutting teeth, and consequently just
foramen^1' under the edge of the orbit; it is broad at its origin;
in. upper it lies flat and runs downwards, and obliquely inwards,
lip and or- to the middle of the lip, till it meets its fellow just in
muscie!S the filtrum.* It pulls the upper lip and the septum
of the nose directly upwards. It generally receives
a slip from the orbicularis oculi.
Levator VII. The levator anguli oris is Called also
anguh ons. levator communis labiorum, because it operates
equally on both lips. It is named caninus ; for as
Or. super, the last-named muscle rises from the upper jaw-bone
maxillary b. above the incisores or cutting teeth, this arises above
the firstnmo- the canini or dog-teeth, or above the first grinder, by
laris and a very short double tendon. The exact place of its
the inf. orb. orjgjn js }ia]f way betwixt the first grinder and the
In. angle o^ infra orbitary hole: it is mixed with the orbicularis
the mouth. oriSj aj- £]ie COmer of the mouth, so that it raises the
angle of the mouth upwards,
zygomati- VIII. The zygomaticus major arises from the
o!s. osTnaia: cheek-bone near the zygomatic suture ; it runs down-
near the zy- wards and inwards to the corner of the mouth ; is a
gomatic su¬
ture. * The filtrum is the superficial gutter along the upper lip from
the partition of the nose to the tip of the lip.
FACE, EYE, AND EAIt.
267
long and slender muscle, which ends by mixing its ln- angie of
fibres with the orbicularis oris and the depressor of the mouth"
the lip.
IX. The zygomatic us minor arises a little higher zygomati-
upon the cheek-bone, but nearer the nose ; it is much ™°ariffi
slenderer than the last, and is often wanting. In higher and
negroes we frequently find three zygomatic muscles. noseThln6
It is the zygomatic muscle that marks the face with the last-
that line which extends from the cheek-bone to the between the
corner of the mouth, and which is so strong in many. lev. prop. &
The zygomatic muscles pull the angles of the zysomaj°r-
mouth upwards as in laughter ; or one of them dis¬
torts 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 Buccinator,
to be a muscle of the lower jaw, arising from the upper
alveoli, and inserted into the lower alveoli to pull the
jaw upwards ; but its origin and insertion, and the
direction of its fibres, are quite the reverse of this.
For this large flat muscle, which forms, in a manner, 0r■1- alye-
the walls of the cheek, arises chiefly from the coro- wVr'jaw^
noid process of the lower jaw-bone, and partly also ^the coro-
from the end of the alveoli or socket process of the "^he space
upper-iaw, close by the pterygoid process of the between the
1 -j 1 • j ' I /• • -i. last molaris
sphenoid bone ; it arises also from the upper jaw; it ofuPPer
goes forwards with direct fibres to be implanted into Jawandpte-
the corner of the mouth, within the orbicularis. It ofgSphenoid
is thin and flat, and forms the walls of the cheek ; it bo?e- 4-the
is perforated in the middle of the cheek by the duct ptery.Vo.0
of the parotid gland. Albinus describes two irre- In. into the
gular sets of fibres, besides mentioning those which are
running directly to the angle of the mouth : 1. One
narrow slip which runs in a semicircular 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 buccinator. These are use.
its principal uses ; that it flattens the cheek, and so
assists in swallowing liquids : that it turns, or helps to
268
muscles of the
turn, the morsel in the mouth while chewing, and
prevents its getting without the line of the teeth : in
blowing wind instruments, 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 con¬
tinually full ; and from this it is named, from blowing
the trumpet, the buccinator.
depressor xi. Depressor anguli oris. — The depressor
anguli oris. n , • i i •
anguli oris is a neat small triangular muscle, and is
indeed very commonly named musculus triangu-
°r -the base laris labiorum, from its shape. The base of the
of the lower i t n l i • i i
jawnearthe triangle is at the line ot the lower jaw, where the
dim. muscle rises with a fat fleshy edge, more than 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 oppo-
in. the site to the zygomatic and levator muscles ; and as the
mouth'/ thc 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 laugh¬
ter, smiling, &c. the zygomatics and levators pull the
angles of the mouth upwards. In fear, hatred, re¬
venge, contempt, and the angry passions, the trian¬
gulares pull the corners of the mouth downwards;
and at the place where these meet, there is formed a
sort of rising at the angle of the mouth : for a great
many tendons are crowded into this one point; the
zygomatic, levator, depressor, and orbicularis oris
muscles meeting and crossing each other at this
place.
l^biTirTferi XII. The depressor labii inferioris is a Small
oris. muscle, the discovery of which Cowper claims for
himself. It is a small muscle, lying on each side of
the chin, which, with its fellow, resembles very much
Or. base ot |.|ie levators of the upper lip. The depressor labii
tower law. x x x I
FACE, EYE, AND EAR.
269
inferioris arises 011 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 In. middle
where the muscles of the opposite side meet, there otlowerllp-
is a little filtrum or furrow on the lower lip, as on
the upper one. It mixes its fibres with the orbicu¬
laris, and its use is to pull the lip downwards ; each
muscle is of a square form, and thence has been often
named quadratus gen^e, the square muscle of the /
chin.
XIII. The orbicularis oris, or muscle round the Orbicularis
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
semicircular muscles, the semi orbicularis superior,
and semi orbicularis tnferior. Its fixed points are
the two angles of the mouth ; at that swelling which Attached
is formed by the union of the zygomatic, triangular, areolar
and other muscles, part of it takes origin from the process-
alveolar processes of the canine teeth. The chief use
of this muscle is to contract the mouth, and antago¬
nize the other muscles which I have just described.
Often a small slip runs up from the middle of the
upper lip to the tip of the nose ; it is the nasalis nasair*
labii superioris of Albinus ; it lies exactly in the o^*hpen*
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 ; their great office Their ac-
is to perform those continual movements, which ,ion*
breathing, speaking, chewing, swallowing, require.
There are muscles for opening the mouth in various
directions, which are all antagonized by this one,
%70
MUSCLES OF THE
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, open¬
ing the mouth. The angularis 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 phenomenon of the orbicularis
muscle, dilating to such a wideness, and in an instant
closing the mouth again, with such perfect accuracy,
as to retain the breath, puts to nought all the vain
calculations about the contraction of muscles, as that
they can contract no more than one third of their
length ; for here is an infinite contraction, sucli as
no process can measure. It is a paralysis of these
muscles that so often occasions a hideous distortion
of the face ; for when one side of the body falls into
palsy, the muscles of one cheek cease to act; the
muscles of the other cheek continue to act with their
usual degree of power. This contraction of the
muscles of one cheek excites 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
Depressor XIV. The depressor labii superioris and alie
ah® nasi. nasi, which is very small, and lies concealed under
face, eye, and ear.
271
the other muscles. It rises from the gum or socket 0r• alveoiar
of the fore teeth, and thence is named, by Winslow, In d sores"
incisivus medius. It goes into the root of the nos- tae"(Jhcanine
tril, and pulls it, and, of course, the upper lip down, ^ c'orner
and is named, by Albinus, depressor alee nasi. oftheaiaof
XV. The constrictor nasi, or compressor of the ^ pan'of
nose, is a small scattered bundle of muscular fibres, the upper
which crosses the wings, and goes to the very point ^mpres
ol the nose ; for one arises from the wing of the nose sor naris.
on each side, and meets its fellow in the middle
ridge, where both are fixed into the middle cartilage, os. nasi,
or into the lower point of the nasal bones meeting ^ I^sal
with the peak of the frontal muscle, or its scattered max. bone,
fibres. But this muscle is so difficultly found, that f^eakn^f
when Cowper saw it distinctly marked in Bidloo'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 levator
the lower jaw, at the root of the cutting tooth, has inferi"
been named incisivus inferior. It is inserted into Or. alveoli
the skin, on the very centre of the chin: by its oftheinci-
•/ %/ sores and
contraction it draws the centre of the chin into cl caninus.
dimple ; and from its moving the under lip at the In•chin-
same time, it is named levator labii inferioris j
sometimes the superbus.
muscles of the external ear.
Though perhaps not one of ten thousand has the
power of moving the outward ear, yet there are
many thin and scattered fibres of muscles about the
root of the cartilage of the ear, to which we cannot
refuse the name and distinction of muscles; 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 muscles.
The celebrated Mr. Mery was wont, when lecturing
on this subject, to amuse his pupils, saying, plea¬
santly, " that in one thing, he surely belonged to
MUSCLES OF THE
Superior
auris.
Or. tendon
of occipito-
frontalis.
In. back
part of the
antihelix.
Anterior
auris.
Or. zygo¬
matic pro.
In. the
point of
the helix
that divides
the concha.
Posterior
auris.
Or. mas¬
toid pro¬
cess.
In. back
part of the
concha.
the long ear'd tribeupon which, he moved his
ears very rapidly backwards and forwards.*
XVII. Superior auris is named attollens because
it lifts the ear upwards: it is a very thin, flat ex¬
pansion, which can hardly be distinguished from the
fascia of the temporal muscle, upon which it lies; it
arises broad and circular, from the expanded tendon
of the occipito-frontalis, and is inserted into the back
part of the antihelix.
XVIII. Anterior 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 delicate 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 f ; 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 carti¬
lages of the outward ear. They, in all probability,
prepare the cartilages of the ear for receiving and
propagating the vibrations of sound inwards along
the tube of the ear.
The ring and other bendings of the outward ear
are called helix and antihelix, tragus and antitragus ;
and this determines the names of these ambiguous
fibres, which are sometimes found lying upon these
circles of the outward cartilage, just under the skin.
XX. The musculus helicis major lies upon the
upper or sharp point of the helix or outward ring;
* Vide Palfin, who was his pupil. The celebrated Albinus
could move his ears.
f Fibrae carneae transversa^, a nobis descriptae Valsalva.
face, eye, and ear.
rising from 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 fore part 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 antitragicus lies on the antitragus,
running up from this cartilage to be inserted into
the edge of the concha, at the notch on the termi¬
nation of the helix.
XXIV. And, lastly, There is the transversus
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.
The 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
fore part, where the expansions of their colourless
tendons form what is called the white of the eye.
Now these four muscles, coming in a straight course
from the optic foramen 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
vol. t. t
muscles of the
edge of the orbit; one rises from the lower edge of the
socket, and goes backwards under the eye-ball; the
other rises, indeed, along with the recti, in the bot¬
tom 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
backwards ; 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 out¬
wards from the socket.
The truest description of the recti is as of one
muscle, since their only variety is that difference of
place, which is expressed by the name of each.
They all agree in these chief circumstances, that
they arise by flat, but small tendons, round the mar¬
gin 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 wide ten¬
don, which covers all the fore part 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 circle,
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 respect of length ; for the optic nerve enters
the eye, not regularly 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.
face, eye, and ear.
27 5
XXV. The rectus superior, lifting the eye directly
upwards^ is named the musculus attollens, the le¬
vator oculi or superbus, as expressive of haughti¬
ness and pride.
XXVI. And the rectus inferior, which is directly
opposite to it, is named deprimens oculi or humilis,
as expressing modesty and submission.
XXVII. The rectus internus is called adducens,
as carrying the eye towards the nose_, or bibitorius,
because it directs the eye to the cup.
And (XXVIII.) the rectus externus, the outer
straight muscle, as it turns the eye away, is named
abductor oculi, or indignabundus, expressing anger
or scorn. Such is the effect of these muscles, that
when they act in succession, they roll the eye ; but
if they act all at once, the power of each is balanced
by the action of its opposite muscle, and the eye is
immoveably fixed. 80 that sometimes in our oper¬
ations, when the couching needle approaches the eye,
fear comes upon the patient, and the eye is fixed by
a convulsive action, more firmly than it could be by
the instruments, or by the finger; so that the specu¬
lum oculi is after such an accident of no use. The
eye continues fixed during all the operation, but it
is fixed in a most dangerous way, by a power which
we cannot controul, and which sometimes, when our
operation is for extracting one of the humours only,
squeezes out the whole.
XXIX. The obliquus superior or trochlearis obiiquus
arises along with the recti in the bottom of the eye su^cnor-
above, and towards the inner side, directing its long f^°f
tendon towards the inner angle of the eye ; and there
optimum.
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
276
MUSCLES OF THE FACE, EYE, AND EAR.
pulley, which is in the margin of the socket. The
pulley is above the eye, and projects farther than the
most prominent part of the eye-ball, so that the
tendon returns at an acute angle, and bends down-
in. the wards before it can touch the eye-ball. And it not
half way be- only returns backwards in a direction opposite to the
tween the recti muscles, but it slips flat under the body of the
insertion of , • j • i j i •i
rect. sup. rectus superior, and is spread out under it upon the
ofthToUc middle or behind the middle of the eye, viz. about
nerve6 °pUC half way betwixt the insertion of the rectus, and the
entrance of the optic nerve.
Obiiquus XXX. The obliquus inferior is, with equal pro-
mferior. priety, named the musculus brevissimus oculi. It is
directly opposite to the obliquus superior in form,
Or. outer place, office, &c. for it arises from the orbitary pro-
pro.e of sup". cess the superior maxillary bone, near its union
max. bone, with the os unguis : it is short, flat, and broad, with
a strong fleshy belly : it goes obliquely backwards
In. sclero- and outwards, lying under the ball of the eye; and
Se the ° it inserted broad and flat into the ball, exactly
obiiquus opposite to the insertion of the obliquus superior
superior. JTluScle.
These two muscles are' said to roll the eye, whence
they are named musculi circumagentes, or amatorii.
It was Winslow's opinion that they had another
office, viz. supporting the eye-ball, for the operation
of its straight muscles : for when the obliqui act,
they pull the eye forwards, the straight muscles resist,
and the insertion of the oblique muscles at the middle
of the eye-ball becomes, as it were, a fixed point, a
centre or axis round which the eye-ball turns under
the operation of the recti muscles. The conjoined
effect of the oblique muscles is to bring the eye-ball
forwards from the socket. 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
downwTards, and towards the nose. And the par¬
ticular 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 still
there is some difficulty here, for if the question be
13
muscles of the lower jaw.
277
put, — does not the eye-ball roll in all directions ?
we must answer that it does: which, if it were in
any measure accomplished through the operation of
the oblique, there should be four, and not two.*
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 temporal, masseter, and pterygoid
muscles; but, in moving downwards, the jaw almost
falls by its own weight, and having little resistance
to overcome, any regular appointment of muscles
for pulling down the jaw is so little needed, that it is
pulled 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 belong ; 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 Tempo-
of the jaw.t It arises from all the flat side of the ™*lsj
parietal bone, and from the sphenoid, temporal, and micircuiar
frontal bones, in that hollow behind the eye, where
they meet to form the squamous suture. It arises bone,
also from the inner surface of that strong tendinous fquf^r0ssa0l
temporal b.
* The subject of the action of these muscles is taken up again,
when discussing the physiology of the eye. See Vol. III.
f Temporal Fascia.—Before dissecting these muscles of the
jaw, the student must make himself acquainted with the strong
fascia which covers the side of the head, and covers the temporal
muscle. This strong tendinous web is continued from the peri¬
osteum of the temporal ridge of the os frontis, and from the
jugum ; it extends over the temporal muscle, and is attached to
the ridge of the parietal bone, where it may be again traced into
the pericranium. The surgeon has to take particular notice of
this fascia, for, in wounds of the head, when matter gets under it,
the fluid sinks deep, and perhaps appears at the angle ot the jaw.
278
MUSCLES OF THE
membrane which is extended from the jugum to the
3. ex. ang. semicircular ridge of the parietal bone. The fibres
taTbone"01 are bundled together and pressed into a small com-
4. temporal pass, so that they may pass under the iugum : there
plate of the £ , i i i j ,i 0
sphenoid, they take a new hold upon the inner surface of the
5. zygoma- jUgum • the muscle is of course pyramidal, its rays
6° f™m T converging towards the jugum; its muscular fibres
ferfno-Ti e are intermixed with strong tendinous ones ; it is par-
muscle. ticularly tendinous where it passes under the jugum ;
and it has both strength and protection from that
in. the tendinous plate which covers it in the temple. Its
coronoid . . r. , . , n 1
pro. of in- insertion is into the coronoid process or the lower
boner max 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.
Masseter. XXXII. The masseter is a short, thick, and
fleshy muscle, which gives the rounding of the cheek
Or. 1. sup. at its back part. It arises from the upper jaw-bone,
—^ at the back of the antrum, and under the cheek-bone,
maisB, and and from the lower edge of the zygoma. It lies
m^inhf0" upon the outside of the coronoid process, covering
whole the branch of the lower jaw quite down to its angle,
length. jt particularly strong, has many massy bundles of
of the*angle flesh, interspersed with tendinous strings. Indeed,
and the in dissection, this muscle may be divided into two
inf.maxiiil portions, which cross each other obliquely; which
reminds us that the action of the muscle is not simply
to close the teeth, but also to produce the lateral or
grinding motions of the jaw. 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.
The parotid gland lies on its upper part, and the duct
of the gland (as it crosses the cheek) lies over this
muscle.
pterygoi- XXXIII. XXXIV. The two pterygoid muscles
deus inter- there are four in all, two on each side,) are
Or. i. in- named from their origin in the pterygoid processes
ner and Qf sphenoid bone. The pterygoideus internus
upper part , 1 , . , . ,» ,
of internal is that one which rises from the internal or flatter
8
lower jaw, throat, and tongue.
279
pterygoid process, and which goes downwards and pterygoid
outwards to the angle of the jaw on its inside ; it fills 2! the'paia-
up the fossa pterygoidea. tine bone.
The pterygoideus externus arises from the out- t7£
side of the external plate of the pterygoid process the in£
of the sphenoid bone, and from the adjoining part of ptaexr-yg°"°'
the upper maxillary bone. It is inserted into the neck deus exter-
of the condyle of the lower jaw-bone, the upright ex
part of the bone, and to the capsule of the joint. ternai plate
The jaw is moved chiefly by these muscles; the
temporalis acting upon the coronoid process like a cess. 2. the
lever, the masseter acting upon the angle, and before ™0anxeillary
it, and the pterygoideus internus balancing it within, 7n theneck
like an internal masseter fixed on the inside of the and upright
angle. All these pull strongly upwards for biting, jua.tofmax"
holding, and tearing with the teeth ; and the external
or lesser pterygoid muscle, going from within out¬
wards, pulls the jaw from side to side and performs
the motion of grinding.
muscles lying on the fore part of the neck,
and moving the head.
Although we might now, following the order of
functions, be directly led to treat of the muscles of
the tongue and throat, yet we shall, in the first place,
dismiss those, which in dissection, must be first
exposed upon the fore part of the neck.
XXXV. platysma myoides. — This is a very thin piatysma
muscular expansion, which is spread over the other myopes.,
muscles of the neck and throat, and extends upwards,
upon the lower part of the face. It arises by scattered 0r. super_
fibres, which are attached to the cellular membrane, finally <m
betwixt the pectoral and deltoid muscles and the skin panTnhe
of the chest. It extends upwards and forwards, over chesty
the clavicle and the mastoid muscle, going like a thin
teguments
integument over the neck. It terminates on the face d
and jaw. Some of its fibres, mounting over the bone fa'ceeja"'an
of the jaw, are inserted near the depressor anguli
oris ; and others, a little higher on the face, are
called risorius santorini.
t 4
280
muscles of the
Use. This muscle supports the parts in the neck, as
fasciae do elsewhere ; it compresses veins, and forces
the blood down into the chest, when there is difficult
respiration. It is, in truth, more a muscle of re¬
spiration and circulation, than for the motion of
parts, or even for expression ; yet it is very active
in the expression of the stronger passions. In dis¬
secting this muscle the surgical student will have
a regard to a very important part of the surgical
anatomy of the neck. Although there be no proper
fascia investing the neck, for very obvious reasons,
yet the fibres of this muscle interlacing with the
common cellular membrane, form a pretty dense
and firm covering. It will be noticed in dissec¬
tion, that this compound web is very particularly
connected to the transverse processes of the ver¬
tebrae, to the mastoid process, and to the angle
of the jaw. It will be found, also, to be connected
to the clavicle and first rib, and to make a sort of
septum betwixt the region of the neck and the
thorax.
The reason of the difference in the texture of this
web in comparison with the fascia of the extremities,
is to provide for the freedom of the trachea, and to
permit its easy motion.
Mastoi-
XXXVI. Sterno-cleido mastoideus.—This is
deus- the most conspicuous and finest muscle of the body,
giving the fleshy roundness of the neck, and when in
action rising to produce the most beautiful contour of
the neck, both in man and woman. Its origin and in¬
sertion are shortly described in its name, sterno-cleido
Or. i. ster- mastoideus. It arises from the triangular portion of
clavicle!the the sternum, by a strong round tendon, and from
the sternal portion of the clavicle, by a broader
and more fleshy origin. It ascends upon the neck,
and in such a manner, that the dissector can sepa-
in. the rate the two portions with the handle of his scal-
™roc?ss? peK to their termination. It is inserted into the
and angle mastoid process of the temporal bone, and extends its
temporal attachment backwards upon the mastoid angle of
bone. that bone.
lower jaw, throat, and tongue,
281
When the muscles of both sides act together, they Action,
pull the head downwards, and bring the chin to the
breast; but when one muscle acts, it pulls down the
ear to the shoulder, and so twists the neck, as to
throw the chin a little up, and to the other side.
This effect of the single muscle it is important to
notice, because this muscle is subject to a disease
which produces wry neck; and it requires a know¬
ledge of anatomy to distinguish the different causes
of this distortion, whether arising from paralysis or
disease of muscle, or affection of the spine, &c.
muscles of the throat and tongue.
The muscles of the throat and tongue can¬
not be understood 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
below the chin, the uppermost of the hard points
which are felt in the fore part of the throat. Next,
it has two long horn-like processes, which go back¬
wards along the sides of the throat, called the cor-
nua, or horns of the os hyoides, and which are
tied by a long ligament to the styloid process of
the temporal bone. And, lastly, it has small car¬
tilaginous 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 joining of the horns to the
body, and these are named the^ appendices of the os
hyoides, or the lesser cornua.
282
muscles of the
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 wind¬
pipe. Its horns extend along the sides of the throat,
keeping the openings of the windpipe and gullet ex¬
tended, 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 muscles of the throat
and tongue, and the centre of all their motions. It
is the centre of the motions of the tongue, for it
is the origin of these muscles which compose chiefly
the bulk of the tongue ; of the motions of the trachea
or windpipe, for it forms at once the top of the
windpipe, and the root of the tongue, and joins them
together; of the motions of the pharynx or gullet,
for its horns surround the upper part of the gullet,
and join it to the windpipe ; and it forms the centre
for all the motions of the throat in general : for
muscles come down from the chin to the os hyoides,
to move the whole throat upwards ; others come up
from the sternum, to move the throat downwards ;
others come obliquely from the coracoid process of
the scapula, to move the throat backwards, while the
os hyoides still continues the centre of all these
motions.
The trachea, or windpipe, is that tube which
conveys the air to the lungs ; and the larynx is the
head or figured part of that tube which is formed
like a flute for the modulation of the voice, and
consists of cartilages, that it may stand firm and
uncompressed, either by the passage of the food,
or by the weight of the outward air; and that it
might resist the contraction of the surrounding parts,
lower jaw, throat, and tongue.
283
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 meet¬
ing of the two sides being in the middle line of the
throat. This prominent line of the thyroid cartilage
is easily felt in the middle of the throat, is about an
inch in length, and makes that tumour which is
called the pomum Adaini. The flat parts of the
thyroid cartilage form the sides of the larynx. 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 windpipe. Ancl upon its back, or deeper
part, are seated those two small cartilages, which,
with their ligaments, form the opening for the
breath.
The arytenoid cartilages f are two small trian¬
gular bodies, seated within the protection of the
thyroid cartilage. They are foolishly described with
cornua, ridges and surfaces, when they are so small
that nothing further can be observed of their forms,
than that they are somewhat conical; that the base
or broad part of each sits down upon the upper edge
of the cricoid cartilage at its back ; that the point of
each stands directly upwards, and is a very little
crooked, or hook-like ; that standing, as they do, a
* From y.jjivto;, a ring.
•f From ctpvTccivc.f <m ewer, and stho;, like.
28 4
muscles of the
little apart from each other, they form together an
opening something like the spoilt of an ewer, whence
their names. And these cartilages being covered
with the common membrane of the throat, which is
thick, and full of mucous glands, the opening gets
a regular appearance with rounded lips. From the
bases of these cartilages to the back part of the
thyroid cartilages ligaments called the cordw vocales
are extended; over these ligaments the lining mem¬
brane of the larynx is laid, and betwixt them is
formed the chink or rima glottidis ; viz. the opening
of the windpipe. The voice is, in a considerable
degree, formed by the motion of these cartilages and
their ligaments, and the action of the muscles of the
arytenoid cartilages are so exquisitely minute, that
for every changing of the note (and there are some
thousand gradations in the compass of the voice) they
move in a proportioned degree.
The epiglottis is a fifth cartilage of the trachea,
belonging to it both by connection and by office.
It is a broad triangular cartilage, not so hard as the
others, very elastic, and so exactly like an artichoke
leaf, that no other figure can represent it so well.
Its office is to defend the opening of the glottis. It
is fixed at once to the os hyoides, to the thyroid
cartilage, and to the root of the tongue, and it hangs
obliquely backwards over the opening of the rima, or
chink of the glottis ; it is suspended by little peaks
of the membrane, which we call ligaments of the
glottis, and it is said to be raised or depressed by
muscles, 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 windpipe.
Then this is the constitution of the larynx. It is
of hard cartilages to resist compression, and of a
flute form at its opening, 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.
lower jaw, throat, and tongue.
28 5
The cricoid cartilage, which forms the upper ring
of the trachea, supports the arytenoid cartilages, and
by its deepness behind raises them so, that the open¬
ing 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 arytenoid
cartilages and ligaments 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 sing¬
ing, widening or contracting in most delicate 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, standing over it, flaps down like the
key of a wind instrument, so that the rareness of
such accidents is wonderful, when we consider 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 explained 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 through these, as centrical points,
move thejaws, 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 windpipe.
The muscles which pull the throat down are
these:
XXXVII. The STERNO-HYOIDEUS, which passes Sterno-
from the sternum to the os hyoides, a flat, broad,
ribbon-like muscle, arises from the upper piece of the of first rib.
sternum, rather within the breast, and partly also fn^aratnj.
from the clavicle and cartilage oi the first rib, goes sternum,
286
muscles of the
^etJjeac!avi" flat and smooth along the fore part of the throat,
thVstcr- mounts nearly of the same breadth to the os hyoides,
num. an(j js implanted into its basis, or that part (which in
theoSa eo comparing the os hyoides to the jaw) we should
hyoides. compare with the chin.
stemo-thy- XXXVIII. The sterno-thyroideus, which passes
in like manner from the sternum to the thyroid car¬
tilage, is like the last, a flat, smooth, ribbon-like
muscle, rather thicker and more fleshy, but very
uniform in its thickness. As the thyroid cartilage is
o j below the os hyoides, the sterno-thyroid muscle must
sternum, lie under the sterno-hyoideus muscle. It arises
fa eo/first" un^er the sterno-hyoideus muscle from the sternum
rib.e ° S and cartilage of the rib, and is implanted into the
in. lower rough line of the lower edge of the thyroid cartilage,
roicfcarti-^" and a little to one side, but not so much as is repre-
lage. sented in Cowper's drawings. It immediately covers
the thyroid gland.
}?™ideiis XXXIX. The omo-hyoideus, which was once
0 1 e"s named coraco-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
Or. siip. j frequently the name of di^astricus inferior. It
costa near 1 J O . .
the notch of arises from the upper edge or the scapula, which is
JfSe"1?' called costa, near its notch, and from the ligament
os hyoides that crosses the notch, and is implanted into the side
SeTJornu! the. os hyoides, where the horn goes off from the
body of the bone.
These three muscles pull down the throat. The
sterno-hyoideus and sterno-thyroideus pull it di¬
rectly downwards: one of the omo-hyoidei acting,
pulls it to one side; but if both act, they assist in
pulling directly down, and bracing the trachea at the
same time a little down to the back. These mus¬
cles are in almost constant action, and are perfectly
lower jaw, throat, and tongue.
287
relaxed only during the action of deglutition, when
they yield to let the throat be drawn up, and the
mouth thrust back.
The muscles which move the throat upward are:
XL. The mylo-hyoideus, a flat and broad muscle, Myio-
which arises from the whole semicircle of the lower hy°ideus-
jaw, i. e. from the alveoli of the backmost grinders
to the point of the chin. It rises from a line Or. from
on the inner surface of the lower iaw-bone, eroes t!ieline01'
1 l l • n i l • i i -i ri(*ge on
down to the basis of the os hyoides, proceeds with inside of the
very regular, straight, distinct, and orderly fibres, jaw>
from the jaw to the os hyoides, is plainly divided in
the middle from the symphysis of the jaw to the In. 1. lower
middle of the os hvoides, bv a middle tendinous and J;d§e °™le
1 • t All i ' 1 i , body of the
white line. And though Cowper denies the authority os hyoides.
of Vesalius, who divides it thus, it is plainly two 2-itsfeiw,
, . . , V, J by a white
distinct muscles one belonging to either side. line.
XLI. The genio-hyoideus is a small neat pair Genio-
of muscles, arising from the chin at a rough point liy0ldeus'
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 on the'inside
the chin, arising from a small tubercle behind the of the sym-
chin ; its beginning is exceedingly narrow: as it
proceeds downwards, it grows flat and broad ; it is jaw.
implanted into the basis of the os hyoides by a in. the body
broad edge, and is a beautiful and radiated muscle. °[^se ^e,
The submaxillary gland lies flat betwixt this muscle the myio.
and the last, and in the middle the submaxillary hy°ldeus-
duct pierces the membrane of the mouth, to open
under the root of the tongue. The two muscles
move the os hyoides forwards and upwards when the
jaw is fixed ; but when the os hyoides is fixed by the
muscles coming from the sternum, these muscles of
the os hyoides pull down the jaw.
XLII. The stylo-hyoideus is one of three beautiful (^s° hyw"
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 com-
288
muscles of the
mon action of drawing back the tongue, and pulling
the throat upwards.
Or. the This one, the stylo-hyoideus, arises from about
IheTtyioid°f the middle of the styloid process, and, going obliquely
process. downwards and forwards, is fixed into the side of the
os hyoides, where the basis and horn are joined.
in. the os Above its insertion, its fibres are split, so as to make
tEnTonof a neat small loop, through which the tendon of the
base and digastric muscle runs. This stylo-hyoideus is some¬
times accompanied with another small fleshy muscle
like it, and of the same name, which was first, per¬
haps, observed by Cowper, and has been named by
Innes stylo-hyoideus alter ; but it is not regular,
nor has it ever been acknowledged as a distinct
muscle.
Digastricus. XLIII. The digastric us or biventer maxillje
inferioris muscle is named from its having two
kT'nSsT"d bellies. One belly arises from a rugged notch along
proTofteiii- the root of the mastoid process, where the flesh is
poraibone, thick and strong; going obliquely forwards 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-
fh fiTod0b7 hy°ideus, and then is fixed by a tendinous bridle to
hyoides,and, the side of the os hyoides ; and then turning upwards
turning up, towards the chin, it ends in a second fleshy belly,
is inserted •
into a rough which, like the first, is flat and of a pyramidal shape,
dertiiechir above the mylo-hyoideus ; and is inserted into
a rough part of the lower jaw, on the inside of the
circle.
Though this muscle is often called biventer max¬
illae inferioris, as belonging to the lower jaw, perhaps
it does more regularly belong to the throat. No
doubt, when the os hyoides is fixed by its own mus¬
cles, from the shoulder and sternum, the digastricus
must act on the jaw; an office which we cannot
doubt, since we often feel it taking a sudden spasm,
pulling down the chin with severe pain and distor¬
tion of the neck. But its chief office is raising the
os hyoides ; for when the jaw is fixed, as in swallow¬
ing, the os hyoides pulls up the throat; and this is
LOWER JAW, THROAT, AND TONGUE.
289
the true meaning of its passing through the noose of
the stylo-hyoideus, and of its connection with the
side of the os hyoides. Then the digastricus and
stylo-hyoideus muscles pull the throat upwards and
backwards.
The muscles which move the parts of the larynx
upon each other are much smaller, and many of them
very minute.
XLIV. The hyo-thyroideus goes down, fleshy Hyo-thy-
and short, from the os hyoides to the thyroid carti-
lage. It arises from the lower border of the thyroid edge of tliy-
cartilage, where the sterno-thyroideus terminates, cartl"
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, in. part of
and is fixed to the lower edge of the os hyoides, base al"
1 ii*1 i n ■ i most a11 tllB
along both its base and part oi its horn. cornu of os
XLV. The crico-thyroideus is a very short crkvJthy-
muscle, passing from the upper edge of the cricoid roideus.
to the lower margin of the thyroid cartilage, chiefly Or. side and
at its side, and partly attached to its lower horn, cricJdear-
which comes down clasping the side of the cricoid tilase-
ring, so that it is broader above, and a little pointed ^ the
bel0W- rLrior
These two small muscles must have their use, and cornu of the
they bring the thyroid cartilage nearer to the os caSge.
hyoides, and the cricoid nearer to the thyroid car¬
tilage ; and by thus shortening the trachea, or com¬
pressing it slightly, they may perhaps affect the voice ;
but the muscles on which the voice chiefly depends
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-arytenoid ligament, govern the rima glot¬
tidis.
XLVI. The MUSCULUS ARYTENOIDEUS TRANSVERSUS Arytenoi-
is that delicate muscle which contracts the glottis by ^utrans"
drawing the arytenoid cartilages towards each other. 0r_ side of
It lies across, betwixt them at their back part; it onearyten-
arises from nearly the whole length of one arytenoid °age!am*
vol. r. u
290
muscles of the
in. side of cartilage to go across, and be inserted into the same
ary.°cart extent of the opposite one.
cfrytobf" XLVII. Arytenoideus obliquus is one which
quus.° " crosses in a more oblique direction, arising at the
Or. base of r0ot of each arytenoid cartilage, and going obliquely
cartnage.ry' upwards to the point of the opposite one. These
in. apex of two muscles draw the arytenoid cartilages together,
the other an(j ciose the rima : frequently we find only one
ary. cart# . <, i
oblique muscle.
Crico-ary- XLVIII. The crico-arytenoideus posticus is a
tenoideus small pyramidal muscle, which arises broader from
posticus. ii i n j • • i -i i i
Or. broad the back part ot the cricoid cartilage, where the ring
part of cri- is broad and deep ; and, going directly upwards, is
Cjn backhand implanted, with a narrow point, into the back of the
outer point arytenoid cartilage. This pair of muscles pulls the
carTytenoid arytenoid cartilages directly backwards, and lengthens
the slit of the glottis : perhaps they assist the former
in closing it more neatly, and in producing more
delicate modulations of the voice.
SSdeT XLIX. The crico-arytenoideus lateralis is one
lateralis"3 which comes from the sides of the cricoid carti-
Or. side of lage where it lies under the wing of the thyroid, and
cricoid cart. being implanted into the sides of the arytenoid car-
the base of til ages, near their roots, must pull these cartilages
the aryten- asunder, and (as the origin of the cricoid lies rather
i°a?e?artl" before their insertion in the arytenoid cartilages) it
must also slacken the lips of the slit; for the lips of
the slit are formed by two cords, which go within the
covering membrane, from the tip of each cartilage
to the back of the thyroid cartilage, and the crico-
arytenoideus posticus must stretch these cords, and
the crico-arytenoideus lateralis must relax them.
Thyro- L. The thyro-arytenoideus is a muscle very
deusenoi" the last one, and assists it. It arises not from
or. back the cricoid cartilage, but from the back surface
and under of the wing of the thyroid, from the hollow of its
row cart'.y~ wing, or where it covers the cricoid ; is implanted
in. nearly into the fore part of the arytenoid cartilage, and by
of PuMing the cartilage forward and sideways, directly
earti'iagef slackens the ligaments, and widens the glottis.
lower jaw, throat, and tongue.
291
There is another muscle, the thyro-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 major and minor, but this we cannot
expect to find always, as it is only in particular bodies
that we see fibres running from the thyroid cartilage
to the epiglottis. 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 aryteno-epiglottideus.*
These are all the muscles which belong to the
larynx ; and in our arrangement the muscles of the
palate and pharynx come next in order.
When a morsel is to be thrown down into the
oesophagus, or tube which leads to the stomach, the
velum palati, or curtain of the palate, is drawn
up wards ; the opening of the throat is dilated ; the
morsel is received; then the curtain of the palate
falls down again. The arch of the throat is con¬
tracted, the bag of the pharynx is compressed by its
own muscles ; and the food is forced downwards into
the stomach.
LI. The AZYGOS UVULvE. The VELUM PENDULUM Azygos
palati is that pendulous curtain which we see uVul£B-
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 or. poster-
point of the palate bones, and pulls the uvula, or i°fextre-
pap of the throat, directly upwards, removing it out paktine
of the wav of the morsel which is to pass.
J In. point of
the uvula.
* There is in Albinus a second set of fibres, which he calls
thyro-arytenoideus alter, arising from the inner and upper part
of the thyroid cartilage, and inserted into the arytenoid cartilage
just above the insertion of the crico-arytenoideus lateralis; this
muscle must have much the same action as the other.
U 2
292
muscles of the
Levator' LII. Levator palati mollis arises from the point
palatl' of the os petrosum, and from the Eustachian tube,
miiyofpars and also fr°m tlie sphen°idbone.* These parts hang
petrosa, over the roof of the velum, and are much higher than
chlif tube ^ 9 so this muscle descends to the velum, and spreads
in. theve- out in it; and its office is to pull up the velum, to
ium palati. remove it from being in the way of the morsel
which is about to pass, and to lay the curtain back
at the same time, so as to be a valve for the nostrils,
and for the mouth of the Eustachian tube, hin¬
dering the food or drink from entering into these
passages.
circum- LIII. The circumflexus palati t, and the con-
paiatL strictor isthmi faucium, have a very different use.
The circumflexus palati is named from its fibres
passing over, or rather under the hook of the pteiiy-
Or. i. spin, goid process; the muscle arises along with the
sphenoid levat°r palati, (i. e.) from the sphenoid bone at its
2. Eusta- spinous process; and from the beginning of the Eusta¬
chian tube. chian tube, it runs down along the tube, in the hollow
3. root of
intern, pte- betwixt the pterygoid processes ; it then becomes
rygoid pro- tendinous, turns under the hook of the internal
pterygoid process, and mounts again to the side of
in. runs the velum. Now the levator and circumflexus arise
hook'fh the from the same points ; but the levator goes directly
downwards into the velum, and so is useful in lifting
it up. The circumflexus goes round the hook, runs
on it as on a pulley, turns upwards again, and so it
pulls down the palate, and stretches it, and thence
serted into
the velum
palati.
* From the Eustachian tube, it was named salpingo-
stapiiilinus; from the sphenoid bone, spheno-stapiiilinus ;
from the pterygoid process, pterygo-staphilinus ; from the
petrous process, it was named petro-salpingo-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
circumflexus palati, tensor palati, pal ato-salpingeus,
staphilinus externus, spheno-salpingo-staphilinus, mus-
culus tub.®, viz. eustachian.® nonus. pterygo-staphilinus
of Cowper, &c.
lower jaw, throat, and tongue.
293
is very commonly named the tensor palati mollis,
or stretcher of the palate.*
LIV. The CONSTRICTOR ISTHMI FAUCIUM arises from Constrictor
the very root of the tongue on each side, goes round faucTum.
the middle of the velum, and ends near the uvula.t Or. side of
This semicircle forms that first arch which presents ^*°Jsguc
itself upon looking into the mouth. root.
LV. The palato-pharyngeus t again forms a ^•hm^1dJieri
second arch behind the first; for it begins in the attheToT
uvula or middle of the soft palate, goes round the oftheuvuia.
entry of the fauces, and ends in the wing or edge of ^^'o. us
the thyroid cartilage ; and as the first arched line Or. middle
(that formed by the constrictor) belonged to the root
of the tongue, the second arched line belongs to the root of the
pharynx or gullet; and between them is lodged the of
amygdala. § The circumflexus palati makes the the upper
curtain of the palate tense, and pulls it downwards : ofthe
the constrictor faucium helps to pull down the curtain, thyroid car-
and raises the root of the tongue to meet it: the tllase*
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, and
the back parts of either jaw-bone. The oesophagus
again is the tube wrhich conveys the food down into
the stomach, and this bag of the pharynx is the ex¬
panded or trumpet-like end of it; or it may be com-
* Some of its posterior fibres mix with the constrictor pha-
ryngis superior and palato-pharyngeus.
f Named glosso-staphilinus, from its origin in the tongue,
and insertion into the uvula.
J The salpingo-pharyngeus of Albinus is no more than that
part of the palato-pharyngeus which arises from the mouth of the
Eustachian tube.
§ In its passage down its fibres are fixed with the stylo-pha-
yngeus, and in its insertion they are mingled with the inferior
constrictors.
u 3
294
muscles of the
pared 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 smooth along the bodies of the vertebrae;
before, it is protected, 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 order, and are
named its constrictors, because they embrace
it closely, and their contractions force down the
food.
Styio-pha- LVI. The stylo-pharyngeus arises from the root
lit of of the styloid process. It is a long, slender, and
the styloid beautiful muscle ; it expands fleshy upon the side of
/n° s7de of the pharynx; extends so far as to take a hold upon
pharynx the edge of the thyroid cartilage ; it lifts the pharynx
part of* llP to receive the morsel, and then straightens and
thyroid compresses the bag, to push the morsel down, and
cartilage, 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 muscle, 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.t
A third bundle, the lowest of the three, arising from
the thyroid and cricoid cartilages, is named the con-
* These good opportunities of bestowing names have not
been disregarded: this muscle has been named cephalo-pha-
ryngeus, pterygo-pharyngeus, mylo-pharyngeus, glosso-
pharyngeus.
t This one is named hyo-pharyngeus, or syndesmo-pharyn-
geus, from its origin in the cartilage also of the os hyoides.
lower jaw, throat, and tongue.
295
stridor inferior. * And it is remarkable that the
lower edges of the superior divisions are clasped and
covered by the upper edges of that which is inferior ;
so that these muscles are like three funnels, one
within the other.
LVII. The CONSTRICTOR SUPERIOR, arising from the Constrictor
basis of the skull, from the jaws, from the palate, and Sorper1'°rc'u.
from the root of the tongue, surrounds the upper neiformpro-
part of the pharynx ; and it is not one circular muscle, ^csip°taib.
but two muscles divided in the middle line behind, 2.Pterygoid
by a distinct rap ha, or meeting of the opposite ^phe/
fibres, t noid.
LVIII. The constrictor medius rises chiefly from
the round point in which the os hyoides terminates ; in. into its
it also arises from the cartilage of the os hyoides ^^ictor
(i. e.) where the horns are joined to the body. The
medius.
tip of the horn being; the most prominent point, and appen-
0 l. jl clix cornu
the centre of this muscle, it goes upwards and down- and'iig. of
wards, so as to have something of the lozenge-like ^h[01^s'
shape ; it lies over the upper constrictor like a second neiformPro-
layer; its uppermost peak, or pointed part, touches c*ss
the occipital bone, and its lower point is hidden by
2. into its
the next muscle. fellow-
LIX. The constrictor inferior arises partly from Constrictor
the thyroid and partly from the cricoid cartilage ; ^
and it again goes also obliquely, so as to overlap thyroid and
or cover the lower part of the constrictor medius. cricoid cart.
This, like the other two constrictors, meets its fellow feu0\v.°
in a tendinous middle line ; and so the morsel ad¬
mitted into the pharynx by the dilatation of its arches,
is pushed down into the oesophagus by the forces of
these constrictores pharyngis, assisted by its styloid
muscles.
The (esophagus is merely the continuation of the
same tube. It lies flat upon the back-bone, and
it is covered in its whole length by a muscular
* This, of course, is named thyro-pharyngeus, and crico-
pharyngeus.
f It is connected with the buccinator, the root of the tongue,
and palate.
u 4
296
muscles of the tongue.
coat, which is formed, not like this of the pharynx,
of circular fibres only, but of fibres running according
to its length chiefly. And this muscle, surrounding
the membraneous tube of the oesophagus, like a sheath,
is named (LX.) vaginalis gul,e.
muscles of the tongue.
Hyo-glos-
sus.
Or. 1. base,
5?. cornu,
3. appendix
of os hyoi-
des.
In. tongue.
Genio hyo-
glossus.
Or. process
behind the
syrnpb. of
lower jaw.
In. 1. tip,
middle, and
root of the
tongue,
2. base of os
hyoides.
Lingualis.
Or. root of
the tongue.
In. tip of
the tongue.
The muscles of the tongue are bundles of fibres,
which come from the os hyoides, the chin, and the
styloid process. Their thickness constitutes the
chief bulk of the tongue. Their actions perform all
its motions.
LXI. The hyo-glossus 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 basio-glossus ; that which arises from
the cartilaginous joining of the body and horn was
called chondro-glossus ; and that which arises from
the horn itself was named cerato-glossus ; or the
terms were all bundled together in the perplexed
names of basio-chondro-cerato-glossus.
The hyo-glossus, 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 divi¬
sion, but which lie all in one plain, and need not
have distinct names.
LXII. The genio-hyo-glossus arises from the rough
tubercle behind the symphysis of the chin. It has a
very narrow or pointed origin; it spreads out fan¬
like, as it goes towards the tongue and base of the
os hyoides; and it spreads with radii, upwards and
backwards, making the chief part of the substance of
the tongue.
LXIII. The lingualis is an irregular bundle of
fibres, which runs according to the length of the
tongue ; it lies betwixt the genio-hyo-glossus and the
hyo-glossus, and as it is in the centre, and uncon-
10
muscles of the arm, &c.
297
nected with any bone, it is named lingualis, as
arising in the tongue itself.
LXIV. The stylo-glossus arises from the styloid Or. styloid
process of the temporal bone, and from a ligament
that connects that process to the angle of the jaw; max. ct
and it is inserted into the root of the tongue, being
insensibly lost on the side and tip of the tongue. in. side
The genio-hyo-glossi muscles form by far the of
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 mo¬
tion ; whence this was named by Winslow, musculus
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 hyo-glossi muscles lie on either side of the
genio-hyoidei, and make up the sides of the tongue ;
and their chief action would seem to be this, that
the hyo-glossus muscle of either side acting, the
edges of the tongue would be pulled downwards,
and the back rounded ; the opposite of which motion
is from the genio-hyoidei acting, by which the middle
of the tongue is made into a groove, the edges rising,
and the centre being depressed. Lastly, The stylo¬
glossus is plainly intended for drawing the tongue
deep into the mouth, particularly affecting the point
of the tongue.
OF THE MUSCLES OF THE ARM,
including the muscles of the scapula, arm, fore¬
arm, and hand.
muscles of the scapula.
The great peculiarity of the arm is the manner of
its connection with the breast, to which it is fixed
298
muscles of the arm, &c.
by the slight ligaments of the clavicle only : but its
union to the body is secured by its strong and nume¬
rous muscles, by which indeed it may be said both
to be fixed and moved. Though it were perhaps
more regular to describe first the muscles of the
' trunk, it will be more easy and natural to describe
first the broad muscles belonging to the scapula,
which cover almost the whole trunk, and hide its
proper muscles, viz. those which move the ribs and
spine. For the muscles which move the scapula lie
upon the trunk; those which move the arm lie upon
the scapula; those which move the fore-arm lie
upon the arm ; and those for moving the hand and
fingers lie upon the fore-arm. The leg requires but
one chief motion, viz. backwards and forwards,
flexion and extension. It has no other motions than
those of the thigh and of the knee ; but the arm
requires an easy and circular 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 motion in raising the arm
is performed, not by the motions of the shoulder-
bone upon the scapula, but by the scapula upon the
trunk. For whenever the shoulder-bone rises to the
horizontal 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.
trapezius. LXV. The trapezius is named from its lozenge
form ; or is often named cucularis, from its re¬
sembling the monk's cowl, hanging back upon the
neck. It is one of the most beautiful muscles in the
muscles of the arm, &c.
299
body; and the two muscles together cover all the
shoulders and neck, with a lozenge-like form, with
neat and sharp points, extending from the 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 Or . I. trans-
the most pointed part of the occipital bone, and
along the transverse spine quite to the mastoid pro¬
cess, by a thin membraneous tendon; from this
point, all down the neck, it has no hold of the ver¬
tebrae, but arises from its fellow in a strong tendon, 2. ligament
which, extending like a bow-string down the neck, nuch®-
over the arch of the neck, and not touching the
vertebrae, till it comes down to the top of the back,
is named ligamentum nuch.®. The tendon begins f
again to take hold of the spines of the two last ver- neck,er
tebrae of the neck, and arises from all the spinous 4vlllthe
processes of the back, downwards; from this long cesses of
origin its fibres converge towards the tip of the dorsal vert-
shoulder : it also comes a little forward over the side
of the neck.
It is implanted into more than one third of the *n- }■ the
clavicle nearest the shoulder; into the tip of the ^Awo-
acromion ; into the whole length of the spine of the mi°n;
scapula, from which the acromion rises ; and its fibres Papula! °f
arising from along the neck and back, and converging
almost into a point, must have various effects, accord¬
ing to the different fibres which act: for those which
come downwards must raise the scapula ; those which
come from the middle of the back must carry it
directly backwards ; those which come from the lower
part of the back must depress it; and those different
fibres acting in succession, must make the scapula
roll. The trapezius is a muscle which moves the
scapula, but it must be also occasionally a muscle of
the head, pulling the head backwards, and bending
the neck. It is also a powerful muscle of respiration,
as may be seen under the head of Respiration.
LXVI. Levator scapula, named also levator levator
proprius angularis, is a small thin slip of flesh, scapul£g-
which arises from the four or five uppermost vertebrae Or. trans,
of the neck, at their transverse processes, by three or f °pp°fr*e°'
four and sometimes five distinct heads. The heads vical vert.
300
muscles of the arm, &c.
In. upper
angle of
scapula.
Rhomboi-
deus major.
Or. spinous
pro. of 4 sup.
dorsal vert.
In. nearly
the whole of
base of scap.
below the
spine.
Rhomboi-
deus minor.
Or. spinous
pro. of 3 last
cervical
vert.
In. base of
scap. oppo¬
site the
spine.
Serratus
magnus
anticus.
join to form a thin and flat stripe of muscle, about
three inches in breadth, which is fixed by a flat thin
tendon to the upper corner of the scapula, to pull it
upwards, as in shrugging the shoulders ; whence it is
named musculus patienti^e.
LXVII. and LXVIII. The rhomboid muscle
stretches flat, neat, and of a square form, betwixt the
spine and the whole line of the base of the scapula.
One part arises from the three lower spinous pro¬
cesses of the neck, and is implanted into the 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 vertebrae
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 (LXVII.) the
rhomboideus minor, the uppermost portion, and
(LXVIII.) the rhomboideus major, the lower portion.
These are seen after raising the trapezius; and the uses
of the trapezius, levator scapulae, and rhomboideus,
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 fore part of the breast.
LXIX. The serratus magnus anticus lies upon
the side of the chest arising from the ribs; and as
the ribs have interstices betwixt them, every muscle
arising from the ribs arises by distinct portions from
each rib : all such distinct and pointed slips are
named digitations, tongues, or sometimes serrae, from
their resembling the teeth of a saw: and every
muscle arising from the ribs must be a serrated
muscle. The serratus magnus anticus is that great
and broad muscle, the chief part of which lies under
the scapula; and nothing of which is seen but the
* We frequently indeed almost find that the rhomboideus
major takes also an origin from the 7th cervical vertebra: it is
so expressed in Albinus.
MUSCLES OF THE ARM, &C.
301
fleshy tongues, by which it arises from the sides of
the ribs. It is all fleshy, and is of a considerable
breadth and strength: it arises from all the true ribs, ^ f!°sm
(it sometimes misses the first rib) and from three of From the 2d
the false ribs : its indigitations, of course, spread all t0 the 9th*
over the side of the thorax like a fan ; its upper in¬
digitations 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 nar¬
rower insertion ; and the muscle ends thick and In. the base
fleshy in the whole length of that line which we call j^ie sca"
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.
One operation of this muscle is upon the scapula;
when the whole acts, it pulls the scapula downwards
and forwards ; when only the lower portions act, it
pulls the lower angle of the scapula forwards, by
which the scapula rolls, and the tip of the shoulder
is raised ; when the upper part acts in conjunction
with the little pectoral muscle, the tip of the shoulder
is fixed and pulled towards the chest, and the lower
corner of the scapula rolls backwards. But its most
important action is in excited respiration, when its
insertion is converted into its origin, and the scapula
being fixed, it expands the ribs, and performs in¬
spiration.
LXX. The PECTORALIS MINOR lies Under the pec- Pectoralis
toralis major, close upon the ribs; and as it arises mmor'
upon the third, fourth, and fifth ribs, it sometimes
takes its origin from the second, third, and fourth Or. 3d, 4th,
ribs, and sometimes only from the third and fourth ; and Sth ribl
it also is a serrated muscle, and was named serratus
minor anticus: its three digitations are very thick
and fleshy ; and soon converge so as to form a small,
but thick and fleshy muscle, which, terminating in jj, In. Cora-
point, is inserted into the very apex of the coracoid of'sca^aT*
302
muscles of the arm, &c.
process : by pulling the coracoid process forwards
and downwards, it will roll the shoulder.
subciavius. LXXI. The subclavian muscle is another con¬
cealed 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
or. cartilage cartilage of the first rib ; it becomes flat and fleshy,
rfb.he lst and lies along betwixt the clavicle and the first rib,
covered with a very firm fascia; it arises at a single
in. into the point of the rib, flat and tendinous, but it is inserted
oTthe a great length of the clavicle; beginning about
vide. two inches from the sternum, and being inserted all
along the clavicle, quite out to where it is joined to
the acromion process, its chief use (since the rib is
immoveable) must surely be to pull the clavicle, and
consequently the shoulder downwards, and so to fix
them.
The scapula is thus moved in every possible
direction : upwards by the levator scapulae and the
trapezius; backwards by the rhomboideus, assisted
by the middle portions of the trapezius; downwards
and backwards by the lowest order of fibres in the
trapezius ; downwards and forwards by the serratus
magnus anticus ; directly downwards by the serratus,
balanced by the trapezius, and assisted by the sub¬
ciavius ; and directly forwards by the pectoralis minor.
MUSCLES OF THE ARM;
viz. those moving the os humeri, or arm-bone.
pectoralis LXXII. The pectoralis major is a large, thick,
OrJi°.sternai and fleshy muscle which covers all the breast. It
half of the arises from the half of the clavicle next the sternum ;
2.aIn the from all the edge of the sternum, the cartilaginous
edge of ster- endings of the three lower true ribs.* Where it
mam. °
* We frequently find slips running as distinct muscles from
the 7th and 8th rib to the humerus; they have been remarked,
in the Windmill-street dissecting-room, more frequently in Las¬
cars and Negroes than in Europeans. In December 1814, 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.
muscles of the arm, &c.
303
arises from the.sternum, it is tendinous, and the fibres 3- cartilages
from the opposite muscle cross and mix, so as to andn'h^ib.
make a sort of fascia covering the bone. It is fleshy
where it arises from the ribs, and there it mixes with
the external abdominal muscle. The fibres approach
each other till they form a flat tendon about an inch
in breadth ; and as the fibres approach each other,
they cross in such a way, that the lower edge of the
muscle forms the upper edge of the tendon, which
is still flat, but twisted ; its implantation is into the in. outside
edge, if I may call it so, of the groove or rut of the g^lfo?1
biceps tendon. That part which arises from the humerus,
clavicle is a little separated from that which arises
from the sternum ; a fatty line makes the distinction ;
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. *
LXXIII. The latissimus dorsi is the broadest, ^Jsimus
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 muscle. It arises
by a broad, flat, and glistening tendon, which covers
all the loins, and which is in some degree the root of
other muscles, especially of the longissimus dorsi.
This broad silvery tendon begins exactly in the
middle of the back ; it arises from the lower vertebrae Or. 1.poster,
of the loins, from the spines and knobs of the back ^lif^i
of the sacrum, and from the back part of the circle the spinous
of the os ilium ; this last is the only part that is fleshy.
The flat tendon gradually passes into a flat and lumbar,
regular muscle, which wraps round the side of the 3®rSpinesof
body, and as it lies over the corner of the scapula, it six or seven
* Haller tells us, that when, at any time, he had rheuma¬
tism in this muscle, his breathing was checked : and when he
had difficult breathing, he found great relief by fixing his hands,
raising the shoulders, and acting with the pectoral muscles. It
seems confirmed by these facts, that asthmatics take this pos¬
ture ; women in labour fix their arms, by resting upon the arms
of their chair; those who play on wind instruments raise the
shoulders in straining.
304
muscles of the arm, &c.
inf.dorsal sometimes receives a small fleshy bundle from it;
inf^ rlils';100 and as it passes over the four lower ribs, it has some
sometimes tendinous slips sent into it, by which it is attached
thf'scapuia. 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 this 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
In. inner of the flat tendon; which, passing into the axilla,
cipitai^bi~ turns under the arm-bone, and is implanted into it,
groove of on the inner edge of the bicipital groove; so the
r'.shume" tendons of the pectoralis and latissimus meet each
other; they, in fact, join face to face, as if the one
tendon ended directly in the other; and both united,
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 powerful, 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 laying 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 down¬
wards and backwards, as in striking with the elbow,
or in rolling the arm inwards and backwards, as in
turning the palm of the hand behind the back,
whence it has the obscene name of musculus scalptor
ani, or tersor ani ; and it forms the back edge of
the axilla. The edges of these two muscles receive
the pressure 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 example
just mentioned, of rising from our seat, or in walking
muscles of the arm, &c.
305
with a short stick, or in raising ourselves by our
hands over a high beam.
LXXIV. The deltoides is the first of those Deitoidcs.
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
the shoulder-bone ; it arises from all that part of the Or. 1. outer
clavicle which is not occupied by the pectoralis t?de,°f°la
muscle, and is separated from it only by a fatty line ;
it arises again in another bundle, from the point of 2.acromion,
the acromion process, and this middle bundle is also
insulated by a fatty line on either side of it. The 3. spine and
third bundle arises from the spine of the scapula, Ease ofsca-
behind the acromion process, and which is also re¬
attached to the base by a strong ligamentous fascia,
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 from the other by a
fatty line.* These heads or bundles of fibres, meet- ^XeTnthe
ing about one third down the humerus, form a short, fore part of
flat, and strong tendon, which grasps or almost th®hume*
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 circumstances ; 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 its power ;
and in proportion as it loses of its power, the side
portions having come into a new direction, begin to
* Albinus has distinguished it into seven fasciculi or bundles ;
a very superfluous accuracy.
vol. i. x
306
muscles of the arm, &c.
help ; nay, when the arm is raised to a certain point,
more power is still 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 lateral portions,
than raised by the middle one. It is still more sur¬
prising that authors have neglected the great and
obvious use of these lateral portions, since they are
the most powerful rotators of the arm, e. g. the guards
in fencing are performed chiefly through the opera¬
tion of these portions of the deltoid muscle.
Coraco- LXXV. Coraco-brachialis.—The coraco-bra-
brachiahs. Gj1jaxis> so named from its origin and insertion, is a
long and rather slender muscle.
Or .fore part It arises from the coracoid process of the scapula,
of coracoid al0ng with the short head of the biceps muscle, and
it is closely connected with this head, almost its
whole length ; it is small at its beginning; it grows
in. inner gradually thicker as it descends ; it is all fleshy, and
ridge of hu- js inserted by a very short tendon into the os humeri,
the middle, 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 Casserius, an Italian anatomist; and the muscle
is often named musculus perforatus casserii.
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.
supra sPi- LXXVI. The supra spinatus is so named from
its occupying the hollow of the scapula above the
spine.
Or.dorsum, It arises from the back of the scapula reaching to
andsu'perior the base, from the spine, and from the superior edge
costa of the 0r costa; it is exceedingly thick and fleshy, filling
scapula. ^ all the hollow between the spine and superior
7ar ofPer cos^a > and it is firmly enclosed in this triangular
great°tube- hollow, by a strong tendinous expansion which passes
rosityofhu- from the superior edge of the scapula to the ridge
of the spine : it is consequently a muscle of a trian-
4
muscles of the arm, &c.
307
gular figure, thick and strong ; it passes under the
acromion, and degenerates into a tendon there, and
going under the acromion, as under an arch, and
over the ball of the humerus, it adheres to the cap¬
sule of the shoulder-joint, and is at last implanted by
a broad strong tendon into the upper part of the
great tuberosity on the head of the bone.
It is evidently designed for raising the humerus
directly upwards, and by its attachment to the cap¬
sule, 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 direction with
it, and assists it.
LXXVII. Infra spinatus is like the former in all infra spi-
respects, of the same use, and assisting it.
This also is of a triangular shape, and is fully one
half larger than the supra spinatus ; and the supra
spinatus arises from all the triangular cavity above
the spine: this arises from almost all the triangular
cavity below it.
It arises fleshy from all the back of the scapula Or. dorsum,
below the spine, except that part giving origin to JJJJ'i'n£ase'
the teres major and minor, from the spine itself, and costa of sca-
from all the base of the scapula, below the beginning pula'
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
expansion ; it begins to grow tendinous about its
middle, but it continues also fleshy till it passes over
the socket of the shoulder-joint: it also is connected middle
with the capsular ligament, is inserted into the middle LTgVtuber-
of the same tuberosity with the former, and has cle of the
exactly the same uses, viz. preventing the capsule humerus*
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 these two muscles is, when the arm
is much extended backwards, to prevent the head of
the humerus from starting out of its superficial socket.
x 2
308
muscles of the arm, &c.
Teres
minor.
Or. edge of
the inferior
costa sea*
pulae.
In.large tu¬
bercle ofthe
humerus
inferior to
the last.
Teres
major.
Or. inferior
angle, and
part of the
inferior
costa of the
scapula.
In. the in¬
side of the
groove for
the long
tendon of
the biceps.
LXXVIII. The teres minor is a third muscle
which co-operates 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
rather flat. The teres minor is a 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 is very distinct in its tendon. The
supra spinatus, infra spinatus, and teres minor, raise
and roll the arm outwards.
LXXIX. 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 considered as the
congener of the latissimus dorsi; and the two tendons
are inclosed in one common capsule, or sheath of
cellular substance.
Its use, then, is evidently to draw the humerus
downwards and backwards, and to perform the same
rotation of t he arms, which the latissimus dorsi does.
8
muscles of the arm, &c.
309
LXXX. The subscapulars lines all the con- 1^j)sscapu~
cavity of the scapula like a cushion. It is like the ans
surface of the scapula on which it lies, of a triangular
shape ; and from the convergence of all the fibres it
is completely radiated or fan-like ; it is very fleshy,
thick, and strong ; the radii are each minutely de¬
scribed by Albinus ; but Sabatier says, with good
sense, that he cannot distinguish them, so as to
describe them accurately ; and he might have added,
that there was not the shadow of a motive for wasting
time in so trivial an employment as counting the
bundles.
It arises from the two costae, the base, and all the 0r- the
internal surface of the scapula. And indeed it is surfecTof
to favour this origin that the inner surface of the the scapula,
scapula is full of little risings and hollows, to every \ inferior8'
one of which the muscle adheres closely. Just under costa>4-
the coracoid process is the only part from whence sup- cos
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 continuous with the supra spinatus ; but from
the manner of its insertion, its effect is very opposite
from that of the supra spinatus, for it goes round
the os humeri to its insertion, and it is fixed to the In. interna
lesser tuberosity, therefore it both pulls the arm S^hum^-
backwards and downwards, and performs the rotation rus-
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 move
this bone, I shall review the order in which they are
arranged, and mark their place and effects.
x 3
310
MUSCLES OF THE ARM, &C.
To distinguish clearly the function of 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. Now the supra spinatus, infra
spinatus, and teres minor, are implanted into the
great tubercle, and raise the arm ; and the deltoides
is implanted in the same direction, and still lower,
so that it performs the same action with a still greater
degree of power.
2. There is implanted into the opposite or lower
part of the head, the subscapularis, which, of course,
draws the arm directly downwards and backwards.
3. There is implanted into the outer edge of the
bicipital groove, the pectoralis major, and also the
coraco-brachialis, which comes in the same direc¬
tion ; and these two pull the arm inwards, towards
the side, and forwards.
4. There are inserted into the inside, or lower
side of the groove, the latissimus dorsi and teres
major, both of which pull the arm directly back¬
wards, 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 suc¬
cession those muscles must act, to describe the cir¬
cular and rotatory 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
suffers. 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
.tendinous connections with the head of the bone are
more than a compensation for the looseness of its
capsular ligament. Were not the muscles thus
muscles of the arm, &c.
311
closely attached^ the shoulders would be very often
displaced, the glenoid cavity is so superficial, and
the capsule so lax ; and surely it is for some such pur¬
pose, that the muscles are planted so closely round
the head; for when they are implanted at a distance
from the centre, as one muscle the deltoid is, or as
the biceps and triceps of the arm, or the hamstrings,
or tendo Achillis, the power is much increased.
Here, in the muscles arising from the scapula, power
is sacrificed to the firmness of the joint, and they
are all implanted closely round the head of the
bone.
The connection of the bones in this joint is in a
manner formed by these muscles, for the supra spi-
natus, infra spinatus, teres major and minor, and the
subscapulars, surround the joint very closely, cover
the joint with their flat tendons, and so thicken the
capsule, and increase its strength.
The muscles of the fore-arm are only four, the
biceps and brachialis for bending, and the triceps
and anconeus for extending.
LXXXI. Biceps brachii flexor is universally Biceps,
named biceps, from its having two very distinct
heads. It is an exceedingly thick and strong muscle,
for when it contracts, we feel it almost like a hard
firm ball upon the fore part 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 co- Or. 1. cora-
racoid process, by a tendon which extends three ^glenoid'
inches along the fore part of the muscle, in the form cavity,
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.
The second, or long head, arises from the edge of
the glenoid cavity, at its upper part; it is exceed¬
ingly small and tendinous, 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
x 4
312
muscles of the arm, SiC.
other muscles, the common division betwixt its two
origins may be still observed.*
ofih'fascia It earlier tendinous at the fore part and outer
arm^ni- side ; the tendon here sends off that aponeurotic
bercieofthe expansion which covers all the arm below, and en¬
closes the muscles as in a sheath. The tendon, at
first flat and large, becomes gradually smaller and
rounder ; and 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 upper 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. e. it will assist the supinators. Since
both its heads are from the scapula, it will occa¬
sionally move the humerus, as well as the fore-arm.
brachial LXXXII. The brachialis internus lies imme-
mternus. diately 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.
Or. the an- It arises from two thirds of the os humeri at its
sur/hce'of f°re part, by a sort of forked head; for it comes
humerus, 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 fore part; and is inserted by a flat
noidprocess strong tendon into the coronoid process of the ulna,
of 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.
* It is not uncommon to find a third head to this muscle, which
takes an origin from the fore part of the humerus.
MUSCLES OF THE ARM, &C.
313
LXXXIII. Triceps EXTENSOR. Upon the back Tricepsex.
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.
The longest head of this muscle is in the middle. Or. 1st
It arises by a flat tendon from an inch of the in-
ferior edge or costa of the scapula, under the neck, puia.
and a little way from the glenoid cavity; 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, and sdhead,
next in length to this. It arises from the arm-bone ridgeofthe
under the great tuber, and just below the insertion humerus,
of the teres minor. The long and second heads meet
about the middle of the humerus.
The third, or internal head, is the shortest of all. fedr^.'din"
It begins at the inner side of the humerus, just of "he hugc
under the insertion of the teres major ; and it arises merus-
from the inner part of the humerus, all the way
down, and joins just where the second head joins
(i. e. about the middle). All these heads still con¬
tinue adhering to the humerus (as the brachialis
does on the fore side), quite down to within an inch
of the joint, and then a strong thick tendon is formed,
by which it is implanted strongly in the projecting
heel of the ulna, named olecranon, by which projec- in. op¬
tion of the bone the muscle has great power, and cranon-
the power is increased by an increased length of the
process in dogs and other animals which run or
bound.
The whole forms a very thick and powerful
muscle, which covers and embraces all the back
part of the arm ; and its use is too simple to admit
of any farther explanation, than just to say that it
extends the hinge-joint of the elbow with great
power ; and that by its long head it may assist also
to bend the arm-bone outwards and backwards.
LXXXIV. The anconeus is a small triangular Anconeus,
muscle, placed on the back part of the elbow. It Or. ridge
arises from the ridge and from the external condyle ^d°y^e„f
314
MUSCLES OF THE ARM, &C.
rus hume~ humerus, by a thick, strong, and short tendon.
From this it becomes fleshy, and after running about
In. flatsur- three inches obliquely backwards, it is inserted by
bade "of the °hhque fleshy fibres into the outer part of the
ulna. ridge of the ulna.
It is manifestly designed for the extension of the
fore-arm, and has only that one simple action.
THE FASCIA OF THE ARM.
Besides bones, there is also another source of
attachment for muscles, that is, the tendinous ex¬
pansions : for the expansions, which go on the sur¬
face 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 acromion process, or rather comes down from
the neck: it is then strengthened by the tendon of
the deltoid muscle ; it descends, covering all the
arm; and before it goes down over the fore-arm, it
is again reinforced chiefly by the biceps, but also
by the tendon of the triceps extensor. One remark¬
able process, or partition of this general fascia, is
sent in from the sheath to be fixed to the outside of
the humerus, all the way down to the ridge of the
outer condyle. Another partition goes down, in like
manner, to the inner condyle, along the ridge which
leads to it j 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 ; and it sends partitions
down among the several layers of muscles in the fore¬
arm, which gives each of them a firm hold.
The fore-arm is covered with this fascia, or strong
tendinous web, which, like that which covers the
temporal muscle, gives both origin and strength to
the muscles which lie under it, which divides the
several layers one from another. This fascia is said
to proceed from the small tendon of the biceps
muscle, though that were but a slender origin for so
great a web of tendon, which not only covers the
MUSCLES OF THE ARM3 &C.
315
-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 connection with the tendon of the
biceps is quite of another kind from that which has
been supposed. I would not allow that the biceps
tendon expands into the fascia, but rather that the
web receives the biceps tendon, 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
lirst moves, and by making the fascia tense, prepares
the fore-arm for those violent actions which are to
ensue. Thus, it may be defined, a web of thin but
strong tendon, which covers all the muscles of the
fore-ann, 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, esta¬
blishing a strong connection among the several layers,
and making the dissection more difficult.
The fascia of the fore-arm is continued to the
wrist, where it is strengthened by the annular liga¬
ment, and passes over the back of the hand even to
the fingers.
The fascia of the fore-arm, and its relation to the
tendon of the biceps flexor, is of much importance
as a piece of surgical anatomy. It has to be particu¬
larly considered in very many cases, as in wounds of
the fore-arm, abscesses forming under it; as in the
inflammation which follows bleeding, and in the
aneurism which is consequent on the wound of the
brachial artery.
MUSCLES OF THE FORE-ARM, CARPUS, AND FINGERS.
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
316
muscles of the arm, &c.
by rolling the radius on the ulna, is named prona¬
tion and supination. When we turn the palm down,
it is said to be prone ; when we turn the palm up-
wards, it is supine. This is pronation and supina¬
tion. The muscles which perform these motions
are the pronators and the supinators, and the
motion itself is best exemplified in the turning a key
in a lock, or in the guards of fencing, which are
formed by a continual play of the radius upon the
ulna, carrying the wrist round in the half circle.
Now, all muscles which are inserted into the radius
turn it or roll it. We have just seen that even the
biceps does so. Therefore, when the student finds a
muscle inserted into this bone, he knows by that
mark that it is either a pronator or a supinator.
c2. The wrist is called the carpus, and, therefore,
those muscles which serve for bending or extending
the wrist are the flexors and extensors of the
carpus.
3. The bending and extending of the fingers can¬
not be mistaken, and therefore the flexors and exten¬
sors of the fingers need not be explained.
These muscles are denominated from their uses
chiefly ; but if two muscles perform one motion,
they may be distinguished by some accident of their
situation or form. And thus, if there be two benders
of the fingers, one above the other, they are named
flexor sublimis and flexor 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 passing in the course of the
ulna. And if there be two pronators, one may be
distinguished pronator teres, from its round shape,
the other pronator quadratus, from its square form.
And this, I trust, will serve as a key to what is
found to be a source of inextricable confusion.
It will be easy to make the origins and insertions
still more simple than the names ; for all the muscles
arise from two points, and have but two uses.
This assertion shall be afterwards qualified with a
MUSCLES OF THE ARM, &C.
few exceptions ; but at present it shall stand for the
rule of our demonstration ; for all the muscles arise
from two points, the external and internal condyles.
The internal condyle is the longer one, and gives
most power: more power is required for bending,
grasping, and turning the hand inwards; therefore
all the muscles which bend the hand, all the muscles
which bend the lingers, 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 is little resistance to opening the hand,
and little power is required in extending the fingers ;
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 inser¬
tion 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.
A kind of artificial memory of the muscles of the
fore-arm may be had by arranging 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, the ul-
naris, radialis, and medius, commonly called pal-
maris longus. — Three extensors, ulnaris, radialis
longior, and brevior. — Three pronators, the teres,
318
muscles of the arm, &c.
quadratus, and the mass of flexor muscles. — Three
supinators, the supinator longus, brevis, and biceps
cubiti. There are three extensors of the fingers, ex¬
tensor communis digitorum, extensor primi digiti,
extensor minimi digiti. — Three extensors of the
thumb, extensor primus, secundus, and tertius. —
Three flexors of the fingers and thumb, flexor digit¬
orum sublimis, flexor digitorum profundus, flexor
pollicis longus. In the arrangement of the muscles
of the fore-arm, it is correct to say that the flexors
arise from the inner condyle, and the extensors from
the outer condyle; but the supinators and pronators
are better distinguished by their insertion: — thus,
all muscles inserted into the radius turn the wrist,
and thus the supinator longus, the supinator brevis,
the pronator teres, the pronator quadratus, and the
biceps, are employed in turning the hand.
muscles inserted into the radius.
LXXXV. 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 condyle, which origin is
condyle of fully two inches in length above the condyle. It also
:r,ume- arises from the intermuscular membrane ; and, as it
lies on the very edge of the fore-arm, it runs betwixt
the flexor and extensor radialis, It becomes thicker
as it passes 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
in. lower a little below, down to the wrist. This tendon be-
radfusf the comes gradually smaller, till it reaches the wrist,
where expanding a little, it is inserted into the lower
head of the radius on its outer side.
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 supination
Supinator
radii lon¬
gus.
Or. ridge
and outer
MUSCLES OF THE ARM, &C.
319
is complete, when the hand is rolled very much out¬
ward, 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.
LXXXVI. The SUPINATOR BREVIS is an internal Supinator
muscle, which forms, with the muscles of the thumb bre"s'
and of the fore finger, a kind of second layer ; and
this one lies concealed, as much as the pronator qua-
dratus 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, 0r- >• ext.
and from the edge of the ulna, and from the interos- thehume-
seous ligament: it is then lapped over the radius, rus>
and is inserted into its ridge ; so that this supinator the uina°
brevis is very directly opposed to the pronator teres, In- r'dgeof
the insertion of the two muscles almost meeting on
the edge of the radius. It is almost circumscribed
to one use, that of preforming the rotation of the
radius outwards ; but perhaps it may also have some
little effect in extending the ulna, and of assisting the
anconagus.
LXXXVII. The PRONATOR TERES RADII is of the Pronator
outermost layer of muscles, is small and round ; tucs"
named pronator from its 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 Or. inner
condyle of the humerus, at its lower and fore part. ridgtyof the
It has a second origin from the coronoid process of the ulna,
ulna; these form two portions, betwixt which passes
the radial nerve. The muscle thus formed is coni¬
cal, is gradually smaller from above downwards, is
chiefly fleshy, but is also a little tendinous, both at
its origin and at its insertion ; and stretches ob-
liquely across the fore-arm, passing over the other the radius.
muscles of the arm, &c.
muscles to be inserted in the outer ridge of the
radius, about the middle of its length.
Its use is to turn the hand downwards, by turning
the radius ; and it will also, in strong actions, be
brought to bend the fore-arm on the arm, or the
reverse, when the fore-arm is fixed, and we are to
raise the trunk by holding with the hands.
LXXXVIII. The pronator quadratus, 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 fore part of the arm, about two inches above the
wrist; it is nearly square, and is about three inches
in length and breadth. Its fibres goes obliquely
the Is: °f across> betwixt the radius and ulna. It arises from
in. edge of the edge of the ulna, adheres to the interosseous
the radms. 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 endeavoured to
explain the muscles of the fore-arm.
Palmar is LXXXIX. The palmaris longus, flexor carpi
medius, 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 annu¬
lar ligament of the wrist, a flexor of the wrist, and,
in some degree, 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 com¬
mon 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.
Or. inner The palmaris longus arises from the inner condyle
an(jdfhscia °f the os humeri, and also from the intermuscular
of the fore- tendon, which joins it with the flexor radialis and
flexor digitorum sublimis, and from the internal sur¬
face of the common sheath. Its fleshy belly is but
Pronator
quadratus.
MUSCLES OF THE ARM, &C.
321
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 fore part of the 1!u annular
annular ligament of the wrist, just under the root of cia pahua-
the thumb. This tendon seems to give rise to the ris-
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
as truly arise from bones. The fascia, which the del-
toides 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 fascialis of the thigh,
does not arise from that muscle, but comes down
from the spine of the ilium, strengthened by expan¬
sions from the oblique muscles 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 pretend to say, that the expansion is wanting
when the muscle is found. The aponeurosis, which
covers the palm, is like the palm itself j of a trian¬
gular 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 meta¬
carpal 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 per¬
pendicular divisions, which take hold on the edges
of the metacarpal bones : and thus there being a
perpendicular division to each edge of each meta*
VOL. i. Y
322
muscles of the arm, &c.
carpal bone, there are eight in all, which form canals
for the tendons of the fingers, and for the lumbricales
muscles.*
bS?saris PALMARIS bRevis is a thin flat cutaneous
OrVfl'stia. niuscle, which arises properly from the edge of
paimaris. the palmar aponeurosis, near to the ligament of
forme and" ^ie wrist; whence it stretches across the hand in
the skin thin fasciculi of fibres, which are at last inserted into
the palmf ^ os pisiforme, and into the skin and fat on the
ulnar edge of the palm. This is the ralmaris
cutaneus of some authors, for which we can find no
use, except of drawing in the skin of the hand, and
perhaps making the palmar expansion tense.
ca^pTradi- XCI. The flexor carpi radialis is a long thin
aiis. muscle 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.
Or. inner Jt arises tendinous from the inner condyle; the
fascm ofThe tendon very short and thick. This tendon at its
fore-arm. origin is split into many (seven) heads, which are
interlaced with the heads of the sublimis, profundus,
paimaris, &c.; consequently this muscle not only
arises from the internal condyle, but also from the
intermuscular partitions (as from that betwixt it and
the sublimis) : it forms a long tendon, which, becom¬
ing at last very small and round, runs under the
in. meta- annular ligament; it runs in a gutter peculiar to
ofXefore6 itself; but in this canal it is moveable, not fixed: it
finger and then expands a very little, and is inserted into the
thumb.the metacarpal bone of the fore finger, also touching
that which supports the thumb.
Its use is chiefly to bend the wrist upon the radius.
But when we consider its oblique direction, it will
also be very evident that it must have some effect in
* There is 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 the fascia
paimaris.
4
muscles of the arm, &c.
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.
XCII. The FLEXOR CARPI ULNARTS is a long muscle, Flexor car-
much like the former ; but as its course is along the pl ulndm
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 °'-j-inner
1 l-ii _ J condyle,
the os humeri, by the common tendon of all the
muscles ; it has also, like the pronator teres, a second
head, viz. from the olecranon process of the ulna, ^°lecra~
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 3. the ridge
has a third origin of oblique fibres, which come from of tI,e ullia'
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 muscle. It 4-theintf-
1 OSSGOUS Ilf,
has still a fourth origin from the intermuscular par- and
tition, which stands betwixt it and the flexor subli¬
mis ; and is also attached to the internal surface of 5-thefasc,a-
the common fascia of the arm. Its long tendon is
at last inserted into the os pisiforme at its fore part,
where it sends off a thin tendinous expansion 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 to¬
gether, 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
riand sideways.
XCIII. The FLEXOR DIGITORUM COMMUNIS SUBLIMIS Flexor di-
is named sublimis from being the more superficial of
the two muscles ; perforatus, from its tendon being
perforated by the tendon of that which lies imme¬
diately below. It lies betwixt the palmaris longus
and flexor ulnaris : it is a large fleshy muscle ; and
y 2
32i
MUSCLES OF THE ARM, &C.
not only its tendons, but its belly also, is divided
into four fasciculi, corresponding with the fingers
which it is to serve,
ternaiin ^ ai'ises fr°m the internal condyle, along with the
dyie, 2. co- other four muscles ; from the ligament of the elbow-
joint; from tlie coronoid process of the ulna; and
and3. sharp from the upper part of the radius, at the sharp ridge,
radfus?'the these origins it becomes very fleshy and thick ;
and, a little above the middle of the fore-arm, divides
into four fleshy portions, each of which ends in a
slender tendon. The tendons begin at the middle of
the fore-arm, or near the division, but they continue
to be joined to each other by fleshy fibres some way
down : and indeed the fleshy fibres cease only when
it is about to pass under the annular or transverse
ligament of the wrist. At this place, a cellular 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 appear cleft; they
pass by the edge of the metacarpal bones, and escape
from under the palmar aponeurosis; and where itends,
viz. at the root of the fingers, a tendinous sheath
begins, in which these tendons continue to beenclosed.
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 tendon 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 forward along the second phalanx, into the
fore part of which they are implanted.
In. second This muscle is exceedingly strong : its chief office
Suhefin- is to bend the second joint of the fingers upon the
gers. 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 metacar-
muscles of the arm, &c.
325
pus, but the hand upon the wrist, and even the fore¬
arm upon the arm.
XCIV. I he flexor digitorum profundus Vel Flexor di-
perforans has so nearly the same origin, insertion, profundus,
and use, that the description of the last is applicable
to this muscle in almost every point. This is of a
lower stratum of muscles ; it lies deeper, and under
the former, whence its name : and by this deeper situ¬
ation it is excluded from any hold upon the tubercle
of the humerus.
It arises from the ulna, beginning at the coronoid 0r-1 e°-
process, and extending all along its internal surface, ^'the ridge
from the whole surface of the interosseous ligament, of the lllna>
from the inner edge of the radius, and also, in some seou" liga-
degree, from the intermuscular membrane, which an(|.
separates this from the sublimis. the radius.
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, corresponding with the
four lingers ; and it is about the middle of the arm
that the tendons begin, and continue to receive mus¬
cular fibres from behind, all down to the ligament of
the wrist: at the wrist these tendons are tied to
each other, and to the tendons of the sublimis, by
loose tendinous and cellular fibres. They diverge
from each other, after passing under the annular
ligament ; and going along in the hollow of the
bones, under the tendons of the sublimis, they first
pass through the bridges formed by the palmar
aponeurosis, then enter the sheaths of the fingers,
and finally pass through the perforations of the sub¬
limis, 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. 1 hey also,
above this, appear themselves split in the middle
without any evident purpose; they pass the second in. last
phalanx, and are fixed into the root of the third. of
And every thing that is said of the use of the sub- fingers.
y 3
326
muscles of the a km, &c.
limis may be applied to this, only that its tendons go
to the furthest joint.
lumbri- XCV. Lumbricales. — I shall here describe, as
a natural appendage of the profundus, the lumbri-
cales muscles, which are four small and round mus¬
cles, resembling the earth-worm in form and size;
of the'd°n whence they have their name. They arise in the
flexor pro- palm of the hand, from the tendons of the profundus,
fundus. and are therefore under the sublimis, and under the
palmar 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
in. middle the middle of the second phalanx. The first lum-
conaese bricalis is larger than the second, and the two first
phalanx. larger than the two last.
The first arises from the side of the tendon of the
fore finger which is next to the radius ; the others
arise in the forks of the tendons ; and though they
rise more from that tendon which is next the ulna,
yet they have attachments to both. Their tendons
begin below the first joint of each finger; they run
very slender along the first phalanx, and they gra¬
dually wind around the bone ; so that though the
muscles are in the palm of the hand, the tendons are
implanted in the back parts of the fingers, and their
final connection is not with the bending 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 I
united by tendinous threads.
Hence their use is very evident; they bend the
first joint, and extend the second ; they perform al¬
ternately either office ; when the extensors act, they
assist them by extending the second phalanx or I
joint: when the flexors act, and keep the first and i
second joint bended, the extending effect of these
smaller muscles is prevented, and all their contrac¬
tion must be directed so as to affect the first joint
only, which they then bend.
MUSCLES OF THE ARM, &C.
327
They are chiefly useful in performing the quick
short motions, and so they are named by Cowper
the musculi fidicinales, as chiefly useful in playing
upon musical instruments.
XCVI. The FLEXOR LONGUS POLLICIS is placed by Flexor lon-
tlie side of the sublimis, or perforatus, and lies under gus Polllcis-
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 Or. inner
downwards, from the place where the biceps is in-
serted, and from the interosseous ligament, all the and inner
length down to the origin of the pronator quadratus : of
nor does it even stop here ; for the tendon continues merus.
to receive fleshy slips all the way down to the pas- in. the last
sage under the ligament of the wrist. It has also the^unlb.
another head, which arises from the condyle of the
humerus, and the fore part of the ulna; which head
is tendinous, and joins that origin which comes from
the radius.
The muscle becomes again tendinous, very high,
i. e. above the middle of the arm; and its small ten¬
don passes under the annular ligament, glides in the
hollow of the os metacarpi pollicis, and separates the
short flexor into two heads, passes betwixt the two
sesamoid 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 indicator 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 011 the metacarpal bones, and occa¬
sionally the wrist upon the radius and ulna.
EXTENSORS.
The muscles which lie upon the outei side of the
fore-arm, the supinators, and the extensois of the fin¬
ders and wrist, all arise from one point, the external
y 4
328
Extensor
earpi rad/a-
lis longior.
Or. ridge
and outer
condyle of
the liume-
muscles of tiie arm, &c.
condyle of the humerus, and are all delivered in
this list:
The extensor carpi radialis longior, ) au extend
The extensor carpi radialis brevior, >t] •
The extensor carpi ulnaris, J
The supinator longus, ") ^.urn ^ie pa]m upwards.
The supinator breyis, j 1
The extensor communis digitorum, — extends all
the fingers, and unfolds the hand.
The extensor primi internodiia
pollicis,
The extensor secundi internodii
pollicis,
The extensor tertii internodii
extend the
several joints
of the thumb.
pollicis, j
The extensor primi digiti vel indicator,—extends
the fore finger.
The extensor minimi digiti vel auricularis,—
extends the little finger.
All these muscles arise from one point, the exter¬
nal condyle. They all roll the radius outwards, or
extend the wrist, or extend the fingers. As the mus¬
cles which are flexors need more fibres, and greater
strength, they arise from the internal condyle, which
is the larger : they lie in a deep hollow, for the bones
of the fore-arm are bent to receive them, and they
form a very thick fleshy cushion: but the extensors,
requiring less power, arise from the shorter process
of the outer condyle, are on the convex side of the
arm, and are thin, having few fibres; for though
there is a large mass of flesh on the inner side of the
arm, forming two big flexors of the fingers, there is
only a thin layer on the outer side of the arm, forming
one flat and weak extensor.
XC VII. 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 the
supinator j it descends all along the back of the
MUSCLES OF THE ARM, &C.
i.m
radius ; and after having become a thick fleshy belly,
it degenerates, a little lower than the middle of the
radius, into a thin flat tendon, which becomes slender
and smaller as it descends; and turning a little more
towards 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 in. meta-
root of the metacarpal bone of the fore finger, in offo°re°
that edge next the thumb. finger.
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.
XCVIII. EXTENSOR CARPI RADIALIS BREVIOR. Extensor
This muscle is almost the same in description, name, aKreWor.
and use, with the former. It arises from the external
condyle; and here a common tendon for many
muscles is formed, just as in the internal condyle;
for from this point arise the extensor carpi radialis
brevior, extensor digitorum, extensor minimi digiti,
extensor carpi ulnaris.
The extensor carpi radialis brevior arises from the Or. outer
outer condyle of the humerus, by the common tendon; "h" hume-
it also arises from the aponeurosis, which lies betwixt rus, and
the extensor digitorum and this ; it grows a pretty ^^r°^the
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 In, meta.
its insertion, which is into the back part of the meta- carpal bone
carpal bone of the middle finger, a little towards kiddie
that edge which is next the radius: some little fibres finser-
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
330
muscles of the arm, &c.
Extensor
carpi ulna-
ris.
Or. 1. outer
condyle,
2. fascia of
the fore¬
arm, 3.back
of the ra¬
dius, and
4. of the
ulna.
In. head of
the meta¬
carpal bone
of the little
finger.
Extensor
digitorum
communis.
Or. 1. outer
condyle,
2. fascia,
3. inter¬
osseous lig.
4. back of
the radius.
so ambiguously on the edge of the arm, that though
they are regularly supinators and extensors, they
become pronators and flexors in certain positions of
the hand.
XCIX. 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 com¬
mon tendon arising from the external tubercle of the
os humeri: it lies along the ulnar edge of the arm:
it also arises from the intermuscular membrane, which
separates this from the extensor 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 accompanied all down to the wrist
with feather-like fleshy fibres.
It is fixed into the outside of the head of the meta¬
carpal bone of the little finger.
Its use is to extend the carpus. And it may be
now observed, that when the two extensors of the
wrist, the radialis and ulnaris, act, the hand is bent
directly backwards; that when the flexor radialis
and extensor radialis act together, they bend the
thumb towards the radius ; and that when the flexor
ulnaris and extensor ulnaris act, they draw down the
ulnar edge of the hand.
C. Extensor digitorum communis. — This muscle
corresponds with the sublimis and profundus, and
antagonises them, and resembles them in shape
as in use. It covers the middle of the fore-arm at
its back, and lies betwixt the extensor radialis brevior
and the extensor minimi digiti.
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 mem¬
brane, 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
muscles of the arm, &c.
331
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 flexors, 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
finger, from the ring finger to the mid finger, and In fore,
from that to the fore finger. So that it seems to be one ^t'gdJ^and
ligament running quite across the back of the hand. ger?
It would be foolish 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
metacarpal bones, along the first phalanx of the
fingers, and being there joined by the tendons of the
interossei and lumbricales, they altogether form a
strong tendinous sheath, which surrounds the back of
the fingers.
Now it is to be remembered, that this muscle serves
only for the fore, middle, and ring fingers : that if it
moves the little finger, it is only by a small slip of
tendinous fibres, which it often gives off at the general
divergence, but sometimes not: sometimes it gives
one slip ; sometimes two; often none at all. And so
the little finger has its proper extensor quite distinct
from this.
The use of the muscle is to extend all the fingers ;
and when they are fixed, it will assist the extensors of
the wrist, as in striking backwards with the knuckles.
CI. The extensor minimi digiti, named also Extensor
auricularis, from its turning up the little finger, as i™1
332 MUSCLES OF THE AIIM, &C.
in picking the ear, should really be described with
the last muscle ; if we see the origin, course, and use
of this muscle exactly the same with it, why should
we not reckon it as a slip of the common extensor,
appropriated to the little finger ?
Or. i. outer Its origin is from the outer condyle, along with
2°fascia 0^ier tendons. It also adheres so closely both
3. intero'ss. to the tendinous partitions, and to the internal surface
4SSTof the common fascia, that it is not easily separated
the ulna. 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 escap-
in. last ing from the ligament of the wrist. It is connected
thealHttie°f with the other tendons, in the manner I have de-
finger. scribed. Close to the wrist, it is connected with the
tendon of the ring finger, by a slip which comes from
it; and at the knuckle, and below it, it is again con¬
nected with the tendons both of the ring finger, and
of all the others, by the cross bands or expansions.
Whatever has been said of the use of the last
muscle, is to be understood of this ; as its extending
its proper finger, assisting the others by its commu¬
nicating 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
interossei 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 ten¬
dons of the interossei and lumbricales, form a split
muscles of the arm, &c.
333
tendon, which meets by two curves at the foot of
the last bone of the fingers, to move the last joint.
CII. The extensor primus pollicis, ol' exteUS01' Extensor
primi internodii pollicis, is the shortest of the three, poinds.
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 cjJse
the edge of the ulna, which gives rise to the in- Ld 2."™-
terosseous membrane itself, and also from the convex vex surface
n n A it of the ra-
suriace of the radius. dius.
The fleshy belly commonly divides itself into two
or three, sometimes four fleshy slips, with distinct
tendons, which, crossing the radius obliquely, slip
under the external ligament of the carpus, and are in. i.trape-
implanted into the trapezium and the root of the
first metacarpal bone, or rather of the first phalanx of pal bone of
the thumb, towards the radial edge, so that its chief the thumb-
use is to extendthe thumb, and to incline it a little out¬
wards towards the radius. It has also frequently a
tendon inserted into the abductor pollicis. It must
also, like the extensors of the fingers, be an extensor
of the wrist: and it evidently must, from its oblique
direction, assist in supination.
CIII. The EXTENSOR SECUNDUS POLLICIS is longer Extensor
than the first. It is named by Douglas the extensor
secundi internodii pollicis; by Albinus, the extensor
minor pollicis.
This muscle lies close by the former. It arises Or. 1. edge
just below it, from the same edge of the radius, and J iite"oss'
from the same surface of the interosseous membrane, lig.and
it runs along with it in the same bending course ; and,
in short, it resembles it so much, that Winslow has
reckoned it as part of the same muscle.
Its origin is from the edge of the ulna, the interos¬
seous ligament, and the radius. Its small round
tendon passes sometimes in a peculiar channel, some¬
times with the extensor primus. It goes over the
334 MUSCLES OF THE ARM, &C.
In. 1st and metacarpal bone of the thumb ; it expands upon the
w^ofthe bone of the first phalanx ; and it is inserted just under
the second joint.
It extends the second bone of the thumb upon the
first; it extends the first bone also ; and it extends
the wrist, and by its oblique direction, contributes
to supination.
CIV. Extensor tertius pollicis. — This, which
bends the thirdjoint, is called in common the extensor
longus pollicis, or extensor tertii internodii pollicis.
And here is a third muscle, which, in form, and place,
and function, corresponds with the two former ones.
Or. i. ridge Its origin is from the ridge of the ulna, and
and sinter- from the upper face of the interosseous membrane ;
osseous lig. and it is a longer muscle than the others, for it
begins high, near the top of the ulna, and continues
the whole way down that bone, and is very fleshy
and thick. It is penniform all the way down to the
ligament of the wrist; and its small tendon passes
the ligament in a peculiar ring. This tendon appears
split, like those of the fingers; it goes along the
ulnar side of the first bone of the thumb, readies
the second, and is implanted there by a small slip of
In. last tendon; and being expanded, it still goes forward
the'tiTinnif. to be inserted 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.
Indicator. CV. INDICATOR. The EXTENSOR INDICIS PRO-
prius has very nearly the same origin, and exactly
the same course with the last, and lies by the side of it.
Or. 1. ridge Its origin is from the ulna, by the side of the ex-
of the uina, tensor ]ongQs pollicis. It has also some little attach-
teross. lig. ments to the interosseous membrane. It, like the
others, is feathered with fibres in an oblique direction
down to the ligament of the wrist.
thumb.
Extensor
tertius
pollicis.
muscles of the arm, &c.
335
Ibis muscle lies under the extensor communis
digitorum: its tendon passes along with the com¬
mon tendon, through the annular ligament; and
near the top of the metacarpal bone, or about the
place of the common junctions of all these tendons,
this one joins with the indicator tendon of the
common extensor.
Its use is in extending all the three joints of the Ia-last
tore finger ; assisting the common extensor in point- before °f
ing with that finger ; in acting independently of the finser-
common extensor; and in helping to extend the
wrist, when the fingers are closed.
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 muscles added in the
palm of the hand ; but as there is little power of
extension needed, no more almost than to balance
the power of the flexors, there are no small muscles
on the back of the hand, the interossei 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 pull the
thumb away from the hand, one to bend it, and one
to pull it towards the hand, opposing it to the rest
of the fingers, and so of the little finger, which has
also three muscles.
336
muscles of the arm, &c.
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 oppo¬
site 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 bones of the carpus,
and from the inside of the ligament, and go to the
inside of the thumb. The adductor arises from
the metacarpal of the mid finger, and goes to the
inner edge of the thumb.
Abductor CVI. The abductor pollicis is only covered by
the common integuments. It begins a little tendi-
nuiar'iig1" nous from the outside of the annular ligament, just
2. trape- under the thumb, and by some little fibres from the
zmm. trapezium ; and, from the tendon of the long ab¬
ductor or extensor primus, it bends gradually round
^tb0f the thumb, and is at last inserted in the back of the
second bone first joint, just above the head of the metacarpal
thumb bone. But it does not stop here; for this flat ten¬
don is now expanded into the form of a fascia, which,
surrounding the first bone of the thumb, goes forward
upon its back part, quite to the end, along with the
common tendon of the extensor. This muscle, like
the others, is covered by a thin expansion from the
tendon of the palmaris, as well as by the common
integuments.
Its only use is to pull the thumb from the fingers,
and to extend the second bone upon the first.
Albinus describes a second muscle of the same
name, having the same course, origin, insertion, and
use : it also arises from the outer side of the ligament
of the wrist, and is fixed into the side of the thumb,
and lies upon the inside of the former muscle.
These two are inserted into the first bone of the
thumb ; but the next is inserted into the metacarpal
bone.
opponcns CVII. The opponens pollicis is often called the
poihcis. flexor of the metacarpal bone of the thumb. It is
7
MUSCLES OF THE ARM, &C.
337
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
opponens.
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 liga¬
ment of the wrist. It is inserted into the edge and 0r-?n-
fore part of the metacarpal bone of the thumb ; and and".1tra¬
its use is to turn the metacarpal bone upon its axis, pezium.
and to oppose the fingers; or, in other words, to in. meta-
bend the thumb ; for I can make no distinction. bone
Therefore, this muscle and the next, which lies close thumb,
upon it, may be fairly considered as but two different
heads of one thick short muscle.
CVIII. The FLEXOR BREVIS POLLICIS is a tWO- Flexor bro-
headed muscle, placed quite on the inside of the visPollicis-
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 considered as one large muscle sur¬
rounding the basis of the thumb.
One head arises from the os trapezium, or base of 0r-. tra*
the thumb, and from the ligament of the wrist. Sa^um,
The other head comes from the os magnum and ^n^3;unci"
unciforme, and from the ligaments which unite the
bones of the carpus.
The first head is the smaller one : it terminates by in. ossa
a pretty considerable tendon in the first sesamoid sesam0ldea-
bone. The second head runs the same course : it
is implanted chiefly in the second sesamoid bone,
and also into the edge of the first bone of the thumb
close by it. The second head is exceedingly mus¬
cular and strong. The heads are completely separated
from each other by the tendon of the flexor longus
passing betwixt them.
vol. 1. z
338
muscles of the arm, &c.
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.
Adductor CIX. The adductor pollicis arises from the
poiiicis. metacarpal bone of the middle finger, where it has a
farpd bone extended base. It goes from this directly across
of the the metacarpal bone of the fore finger, to meet the
thumb. It is of a triangular shape, and flat: its base
in!root of is at ^ie metacarpal bone ; its apex is at the thumb :
the second it is inserted into the lower part or root of the first
thumbfthC phalanx : its edge ranges with the edge of the flexor
brevis: it concurs with it in office; and its more
peculiar use is to draw the thumb towards the fore
finger, as in pinching.
Thus do these muscles, covering the root of the
thumb, form that large ball of flesh which acts so
strongly in almost every thing we do with the hand.
The ball of the thumb is fairly surrounded; it is
almost one mass, having one office ; but as the del-
toides will, in some circumstances, pull the arm
downwards, some portions of this fleshy mass pull
the thumb outwards obliquely; some directly in¬
wards : 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.
Abductor CX. The abductor minimi digiti is a thin fleshy
minimi muscle, which forms the cushion on the lower edge
of1'! os iiand> just under the little finger. It is an
pisiforme. external muscle : it arises from the os pisiforme,
2. rnetacar- and metacarpal bone of the little finger, and from
andean- outer end of the annular ligament. It is inserted
nuiariig. laterally into the first bone of the little finger ; but a
in. root and production of it still goes forward to the second bone
the third of the little finger.
phalanx.
muscles of tiie arm, &c.
339
Its use is to spread the little finger sideways, and
perhaps to assist the flexors.
CXI. 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 in¬
sertion.
Its origin is from the ligament of the wrist, and in
part from the crooked process of the unciform bone.
Its use is to bend the little finger. And indeed the
office and place of both is 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.
CXII. The adductor minimi digiti is sometimes
called the metacarpal of the little finger. It lies im¬
mediately under the former muscle. Its origin is
from the hook of the unciform bone, and the adjoin¬
ing 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 finger antagonist to the others : it
is to this finger what the opponens 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's cup.
CXIII. The abductor indicis is a flat muscle of Abductor
considerable breadth, lying behind the adductor pol- ^.Ttra-
licis, and exactly resembling it, being like the second pezium,and
layer. It arises from the os trapezium, and from the boS^of
first bone of the thumb ; and it is inserted into the the thumb,
back part of the first bone of the fore finger, and In. back of
pulls it towards the thumb. bone.lst
The interossei are situated betwixt the metacar¬
pal bones. They are small, round, and neat, some¬
thing like the lumbricales in shape and size, and in
office resemble the adductors and abductors. Four
are found in the palm which bend the fingers, and
draw their edges a little towards the thumb ; three
are found on the back of the hand, for extending the
z 2
Flexor par¬
vus minimi
digiti.
Or. 1. an¬
nular lig.
and 2. os
unciforme.
In. root
and side of
the first
phalanx.
Adductor
minimi
digiti.
Or. 1. an¬
nular lig.
and 2. os
unciforme.
In. outside
of the meta¬
carpal bone.
340
muscles of the arm, &c.
lingers ; they at the same time perform the lateral
motions of the fingers,
interossei CXI V. The interossei interni arise from betwixt
lnterm. metacarpal bones. They are also attached to the
themeta-0 sides of these bones. They send their tendons
carPai twisting round the sides to the backs of these bones,
^th the And they are inserted along with the tendons of
lumbri- the lumbricales and extensors, into the back of
cales' the finger. They are thus flexors of the first joint,
and extensors of the second joint, as the lumbri¬
cales are.
interossei CXV. The interossei externi are three in lium-
OrTroots of ^er* They ai'ise' like the interni, from the metacarpal
the meta- bones and their interstices, and from the ligaments
bones1 ^ie carpal bones. They are peculiar in having
having two each two heads, therefore named interossei bicipites.
heads. They join their tendons to those of the extensor and
ous expan- lumbricales ; they have therefore one common office
sionofthe with them, that is, extending all the joints of the
communis, 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 forbear
mentioning, because they must be more liable to
perplex than assist: if we but remember their com¬
mon place and office, it is enough. The tendons of
the flexor muscles bend round the finger, along with
the interossei and lumbricales, for a surer hold; con¬
sequently the tendons of the lumbricales, of the in¬
terossei 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 ten¬
dinous fibres.
341
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 many smaller ones. These muscles are related
either to the arm, to the ribs, or to the spine, i. 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 correspond¬
ing with the best order of dissection.
The first, or uppermost layer of muscles, viz.
the trapezius, the levator scapulae, the rhomboidei,
the latissimus dorsi, belong principally to the arm.
The serrated muscles which lie next under these are
muscles of respiration, and belong to the ribs ; while
the splenius and complexus, the muscles of the neck,
the longissimus dorsi, sacro-lumbalis, and the quad-
ratus lumborum, which are muscles of the back, and
the innumerable smaller muscles which lie betwixt
the vertebrae, belong entirely to the spine.
The muscles of respiration properly which are
appropriated to the ribs, performing no other motion,
are,
f which comes from the neck,
1. The serratus pos-J and lies fleshy over the
ticus superior, j ribs, to pull them up-
L wards.
f which comes from the lum-
I bar vertebrae, and lies flat
2. The serratus in- . on tjie jower part 0f thg
ferior posticus, | back, to pull the ribs
downwards,
which are twelve flat mus¬
cles arising from the trans-
3. The levatores j verse process of each ver-
costarum, j tebra, and going down to
the rib below : they raise
the ribs,
z 3
r
342
MUSCLES OF RESPIRATION,
f which lie betwixt the ribs,
4. The intercostal J and fill up all the space
muscles, betwixt rib and rib ; they
also raise the ribs.
And there may be added to these, that muscle,
which, lying- under the sternum, and within the
thorax, is called triangularis sterni, and pulls the ribs
downwards.
Serratus CXVI. The serratus superior posticus lies flat
sup. post. Upon the side of the neck, under the trapezius and
spines of rhomboideus, and over the splenius, and complexus
the neck, muscles. It arises by a flat and shining tendon from
oftheback. the spines of the three lower vertebrae of the neck,
and the two uppermost of the back. It goes obliquely
downwards under the upper corner of the scapula,
in. 2d, 3d, and is inserted into the second, third, fourth, and
4th, 5th, by three or four neat fleshy tongues.
The ligamentum nuchae is chiefly formed by the
meeting of the trapezii muscles ; but the flat tendons
of these upper serrated muscles help to form it. They
are purely levators of the ribs ; their effect upon the
vertebrae, if they have any, must be very slight.
Serrat. inf. CXVII. The serratus inferior posticus is a very
post. broad thin muscle, situated at the lower part of the
back, under the latissimus dorsi, or over the longissi-
mus dorsi muscle.
Or. 2 lower It arises, in common with the latissimus dorsi, from
vert, of the tjie Spines 0f the two lower vertebrae of the back, and
back, 3 sup. -T" i r> i i • ri-ii
of the loins. the three uppermost vertebrae oi the loins. 1 heir
origin, like that of the latissimus, is by a thin tendi¬
nous expansion; it soon becomes fleshy, and, dividing
into three, sometimes four, fleshy strips or tongues,
in. 4 infe- each of them is inserted separately into the ninth,
riorribs. tenth, eleventh, twelfth, lower ribs, near their car¬
tilages. 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
backwards, the effect of which must be to compress
the chest, and in certain circumstances to turn the
spine.
or, of the ribs.
343
CXVIII. The levatores costarum are twelve Levatores
muscles on each side, for the direct purpose of raising costarum-
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 inter- Or. trans-
COStal muscles. The first of the levators arises from ®
the transverse process of the last vertebra of the vertebra?,
neck, and goes down to be inserted into the first rib, In. sup.
near its tuberosity ; and so all that follow arise from °f
a transverse process, and go to the rib below, being
very small and tendinous at each end; but the three Longiores.
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 levatores costarum are a succession of
small muscles, arising from the transverse processes
of the vertebrae, 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-lumbalis; and
often they have connections with these muscles,
sometimes very close.
CXIX. CXX. The INTERCOSTALES EXTERNI run Intercos-
obliquely from the lower edge of one rib, downward
and forward, or in a direction from behind forward, 0rm ]ower'
beginning from the spine, to be inserted into the edge of the
upper edge of the rib below; the muscle is not con-
tinued into the space betwixt the cartilages of the edgeofnexi
ribs. The internal, again, are perfect betwixt the rib-
cartilages of the ribs, but they proceed no further
back than the angles of the ribs. They are further 0r- SUp
different from the internal muscles, inasmuch as they margin
pass obliquely backward and downward from the ^
margin of the one rib to the other.
margin of
These two rows were thought to antagonize each next rib-
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
z 4
346 muscles of the
although in the common exercise of the arms they
are voluntary muscles, in [the excited condition of
the respiratory organs they become powerful agents
of inspiration.
MUSCLES OF THE HEAD, NECK, AND
TRUNK.
The serratus superior posticus being raised, the
splenii come into view, and the splenii being also
lifted, the complexus is fully exposed.
spienius. CXXII. 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 complexus.
Or. 4 sup. Each splenius is a flat and broad muscle, which
the"back, arises from the spinous processes of the neck and
a? th5 inf'k ^ack, and is implanted into the back part of the
head. It arises from the four upper spines of the
in. 5 sup. back, and the five lower of the neck ; it parts from
cesses ofthe its fellow at the fifth vertebra of the neck, so as to
neck °thlhe" sh°w *n ^ie interstice two or three of the uppermost
mastoid0 spines of the neck, with the upper part of the com-
process, the plexus muscle; each splenius goes obliquely outwards
os occipuis. ^ ^ inserted into the occipital ridge, and all along
to the root of the mastoid process. At the third ver¬
tebra of the neck, where the two splenii muscles
part from each other, the tendons of the opposite
splenii are closely connected both with each other
and with the common tendon, which is called liga-
mentum 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
head and neck.
347
by four or five distinct tendons in the transverse pro¬
cesses of the upper vertebras of the neck. This portion
may be dissected apart, and has been considered by
many as a muscle, the splenius colli of Albinus ;
who has distinguished as splenius capitis all that part
arising from the spines of the neck, and implanted
into the head; and as the splenius colli, all that part
which arises from the vertebrae of the back, and is
implanted into the transverse processes of the neck.
These splenii are the right antagonists of the mas¬
toid muscles; both the splenii acting, pull the head
directly backwards; 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.
CXXIII. The complexus is named from the in- compiexus.
tricacy of its muscular and tendinous parts, which are
mixed; from the irregularity of its origins, which are
very wide, it has the names of complexus implicatus
trigeminus, by which the student is warned of the
difficulty of understanding this muscle.
It lies immediately under the splenius ; arises by Or. 7 sup.
distinct tendons, with ten or more tendinous feet, f'0"
from the four lower transverse processes of the ver- dorsal vert,
tebrae of the neck, and from the seven uppermost of neck-'spi'n-
the back ; having also some less regular origins, as ous process
from two spines of the back and from four oblique the back1 °f
processes in the neck. It grows into a large muscle,
which is not like the splenius, flat and regular, but In. the oc-
thick, fleshy, composed of tendon and flesh mixed, Hn"6
filling up the hollow, by the sides of the spines of the from the
neck, and terminating in a broad fleshy head, which SemStoid
is fixed under the ridge of the occipital bone; and process,
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 considered 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 con-
348
muscles of the
fusion, 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 had never 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 particu¬
larly improper to transfer that name to another part
of the muscle which is less complicated. This upper
layer, the biventer cervicis, is attached by a large
broad head to the occipital bone ; in the centre of this
belly there is a confusion of tendon; then there is a
middle tendon about the middle of the arch of the
neck, and the lower part of the biventer arises from
two parts ; first, by one slip of flesh from the two
uppermost spines of the back ; and, secondly, 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 transverse processes of the back. Then
it has four other slips from four oblique or articulating
processes of the neck; which various origins are
gathered into one thick irregular fleshy belly, which
is implanted into the occiput under the great head
of the biventer, and mixed with it. This I have
chosen to explain, lest the student should be embar¬
rassed by false names ; referring him to the first
paragraph for the true and simple description of this
muscle.
tracheio- CXXIV. Trachelo-mastoideus.* — The last
mastoideus. muscie often named complexus major, and this
complexus minor ; but a fitter name is the trachelo-
* It is the trachelo-mastoideus, the mastoideus late¬
ralis, the capitis par-tertius, the complexus minor ; by some
it is considered as a part of the complexus.
head and neck.
349
mastoideus, from its origin in the neck, and its
insertion in the mastoid process.
Its origin is from the three first vertebrae of the Or. the 3
back, and from the five lowest of the neck at their "ppermost
. _ # transverse
transverse processes. Its origins are by distinct processes of
tendons, and its belly is in some degree mixed of ofCtheback,
tendon and flesh, whence its name of complexus and the 5
minor. It is inserted into the mastoid process, just l^nedf.
under the insertion of the occipital part of the In. back of
splenius ; and indeed its long and flat belly lies all pi1.®^t0ld
along under that muscle, so that the order of dissec¬
tion is this : 1. The trapezius. 2. The splenius
capitis. 3. The splenius colli. 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; obliquely, 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.
CXXV. The rectus minor is the shorter of the rectus
two, arising from the first vertebra of the neck. Its minor-
place of origin is a small tuber which stands in the Or. tuber of
place of the spinous process of the first vertebra ; and the atlas*
from that point, where it is tendinous, it goes up to in edge of
the occipital ridge, and is inserted fleshy. os occipitis-
CXXVI. The rectus major is larger. It arises, rectus
in like manner, tendinous, from the second vertebra maJor-
of the neck at its spinous process, and mounting 0r* sP^n°us
n 1 •• ini - 11 • l n Pro* °* t"e
from that, is inserted fleshy into the lower ridge 01 dentatus.
the occiput without the former. These are so placed in. os occi-
that the recti minores appear in the interstice of the pitIS'
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
350
muscles of the trunk.
side. And indeed the same may be said of all the
muscles of the neck.
The obliquus superior and obliquus inferior
correspond very closely in all things with the recti,
but in their oblique direction ; the uppermost, as
being much shorter, has been named obliquus minor,
the lower one obliquus major,
obliquus CXXVII. The obliquus superior arises from the
superior, transverse process of the atlas, and is inserted into
°ro ^"the ^ie enc^ ^ie l°wer occipital ridge. Its use, not-
atias. withstanding its oblique position, is not to turn, but
to bend, the head backwards, for the occipital con¬
dyles, standing obliquely, do not permit the rotatory
motion of the head on the first vertebra. Its insertion
in. end of into the occiput is under the splenius and complexus;
occipTidge. tmt one edge of it is above the insertion of the rectus
major.
obliquus CXXVIII. The obliquus inferior arises from
one vertebra and goes to another. It arises from the
pro. of theS spine of the second vertebra : it goes to the trans-
dentatus. verse process of the first, and it meets the superior
in. trans, oblique muscle; and this one obtains great power,
pro. of the by the lateral projection of the atlas giving it a lever
power. The first vertebra or atlas rolls on the tooth¬
like process of the dentatus ; and while the great and
slow motions of the neck in general are performed
by other muscles, there is a presumption, that the
short and quick turnings of the head are performed
by these oblique muscles.
muscles of the trunk.
The great muscles which move the back and loins
are the quadratus lumborum, sacro-lumbalis, and
longissimus dorsi.
The sacro-lumbalis and longissimus dorsi run by
the side of the spine, and lie immediately under the
latissimus dorsi, which is the outer layer ; the qua¬
dratus lumborum lies again under these, and next to
the abdominal cavity. Although the quadratus lum-
8
muscles of the trunk.
3.51
borum lies deep under the longissimus dorsi muscle,
I shall describe it first, for the sake of a connection
which will be presently understood.
CXXIX. The quadratus lumborum is a flat Quadratns
squared muscle, named quadratus from its square, or
rather oblong form. It arises fleshy from two or ^frjh^pine
three inches of the back part of the os ilium, and ° 1tr^™'
from the ligaments of the pelvis which tie the back pro. oflum-
part of the ilium to the side of the sacrum, and to bar vert*
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 whether to consider these as new
origins or as insertions : but its chief insertion is into In. last rib,
the lower edge of the last rib; and a small production a'orJrtert.
of it slips under the arch of the diaphragm, to be im¬
planted into the body or fore part 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 sacrum, ilium, and loins: the two muscles
lie alongside of each other : the longissimus dorsi is
nearer the spine, and keeps its tendons closer by the
spine. The sacro-lumbalis is farther from the spine,
and spreads its tendinous feet broader upon the sides
of the thorax ; and if one be a little under the other,
it is the outer edge of the longissimus dorsi, which is
a little under the edge of the lumbar muscle.
The common tendon and muscle (for there is for
some way but one muscle) begins thus ; it may be
said to have two kinds of adhesion : for, first, exter¬
nally it appears a broad, flat, and shining tendon,
which arises tendinous from all the spines of the
lumbar vertebras; from the spines of the sacrum, and
from the back part of the os ilium : but the inner
surface of this broad tendon is strongly fleshy; for it
arises fleshy from the back part of the ilium from
the deep hollow betwixt the ilium and sacrum; from
the sides of the long spines of the lumbar vertebrae;
and from their articulating processes, and the roots
350
muscles of the trunk.
side. And indeed the same may be said of all the
muscles of the neck.
The obliquus superior and obliquus inferior
correspond very closely in all things with the recti,
but in their oblique direction ; the uppermost, as
being much shorter, has been named obliquus minor,
the lower one obliquus major,
obliquus CXXVII. The obliquus superior arises from the
superior, transverse process of the atlas, and is inserted into
Or. trans, enc[ Gf the lower occipital ridge. Its use, not-
pro. of the . . . © '
atlas. withstanding its oblique position, is not to turn, but
to bend, the head backwards, for the occipital con¬
dyles, standing obliquely, do not permit the rotatory
motion of the head on the first vertebra. Its insertion
in. end of into the occiput is under the splenius and complexus;
occipJidge. but one edge of it is above the insertion of the rectus
major.
obliquus CXXVIII. The obliquus inferior arises from
one vertebra and goes to another. It arises from the
Pro.SoftheS spine of the second vertebra : it goes to the trans-
dentatus. verse process of the first, and it meets the superior
in. trans, oblique muscle; and this one obtains great power,
pro. of the by the lateral projection of the atlas giving it a lever
power. The first vertebra or atlas rolls on the tooth¬
like process of the dentatus ; and while the great and
slow motions of the neck in general are performed
by other muscles, there is a presumption, that the
short and quick turnings of the head are performed
by these oblique muscles.
muscles of the trunk.
The great muscles which move the back and loins
are the quadratus lumborum, sacro-lumbalis, and
longissimus dorsi.
The sacro-lumbalis and longissimus dorsi run by
the side of the spine, and lie immediately under the
latissimus dorsi, which is the outer layer ; the qua¬
dratus lumborum lies again under these, and next to
the abdominal cavity. Although the quadratus lum-
8
muscles of the trunk.
3.51
borum lies deep under the longissimus dorsi muscle,
I shall describe it first, for the sake of a connection
which will be presently understood.
CXXIX. The quadratus lumborum is a flat Quadratns
squared muscle, named quadratus from its square, or lumborum-
rather oblong form. It arises fleshy from two or Or. 1. spine
three inches of the back part of the os ilium, and
from the ligaments of the pelvis which tie the back pro.rofium-
part of the ilium to the side of the sacrum, and to bar vert-
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 whether to consider these as new
origins or as insertions: but its chief insertion is into In. last rib,
the lower edge of the last rib; and a small production doreafvert.
of it slips under the arch of the diaphragm, to be im¬
planted into the body or fore part 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 sacrum, ilium, and loins: the two muscles
lie alongside of each other : the longissimus dorsi is
nearer the spine, and keeps its tendons closer by the
spine. The sacro-lumbalis is farther from the spine,
and spreads its tendinous feet broader upon the sides
of the thorax ; and if one be a little under the other,
it is the outer edge of the longissimus dorsi, which is
a little under the edge of the lumbar muscle.
The common tendon and muscle (for there is for
some way but one muscle) begins thus ; it may be
said to have two kinds of adhesion: for, first, exter¬
nally 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
surface of this broad tendon is strongly fleshy ; for it
arises fleshy from the back part of the ilium ; from
the deep hollow betwixt the ilium and sacrum ; from
the sides of the long spines of the lumbar vertebrae;
and from their articulating processes, and the roots
352
muscles of the trunk.
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, filling up all the
hollow of the loins. There is an appearance of sepa¬
ration, 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 longissiinus
dorsi and sacro-lumbalis break off from the common
tendon ; and the longissimus keeps close by the
vertebrae, while the sacro-lumbalis is implanted into
the ribs.
longiss. CXXX. The longissimus dorsi is a muscle of
oTi. the the spine. It is not a flat muscle, but round, thick,
os sacrum, and firm, filling up all the hollow betwixt the spine
S and the angle of the ribs. It is of a long form, as its
3. spinous name implies, terminating towards its top almost in
versed™- a point. It has two distinct sets of feet by which it
cesses of the [s inserted; one set of feet more fleshy, but small and
/Ti. the neat, go outwards from the side, as it were, of the
transverse muscle, to be implanted near the heads of the ribs ;
theveTt^of the lower ones farther out than the heads of the ribs;
the back, the upper ones close to the head, and consequently
edgeofIn closer to the spine. These heads are nine or ten in
the ribs ex- number, corresponding with the nine or ten upper-
two1 lowest, most ribs. Another set of heads, which are not so
well seen as this 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 trans¬
verse processes of the vertebrae of the back. This
set of heads is thirteen in number, implanted into the
transverse processes of all the back, and of one ver¬
tebra of the neck.
baHs°~lum CXXXI. The sacro-lumbalis separates from the
longissimus dorsi at the last rib, and is a flatter and
less fleshy muscle : its twelve tendons are flatter than
13
muscles of the trunk.
353
those of the longissimus dorsi, and go out wider from
tlie spine. The tendons next to the longissimus dorsi thTialt. '
run highest up, and are the longest; those farthest
from the spine, i. e. farthest out upon the chest, are
the shortest. It has a flat tendon for each rib, which In all the
takes hold upon the lower edge of the rib. But it curvature^
has another order of small muscles which mix with
it; for as the longissimus dorsi has a double row of n. b. the
insertions, this has another set of attachments, for ^s^Tom
there arises from the surface of each rib, at least of the six or
the six or seven lowest ribs, a small slip of flesh, ^'ltJ°1u'er
which runs into the substance of the sacro-lumbalis, run into its
and mixes with it; and these fleshy slips go by the substance-
name of the additamentum ad sacro-lumbalem, or
musculi accessorii.
Both these muscles, viz. the longissimus andsacro- Cervicalis
lumbalis, terminate in points which reach towards the dens!"'
neck, and under the point of each there lie the roots ^ 5 West
of two small muscles, which go up to move the neck, cesses of™"
Many have referred these slips going up into the neck the neck,
entirely to the muscles I am now describing, calling in. six up-
one an ascending slip of the longissimus dorsi, and
the other a slip of the sacro-lumbalis, while others
have described them as distinct muscles, having but
slight connections with the longissimus and sacro-
lumbalis. Their proper names are cervicalis de¬
scenders, and transve.rsalis colli.
CXXXII. The cervicalis descendens is con¬
nected 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 ver¬
tebrae of the neck, at their transverse processes, 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 inferred from its having dis¬
tinct tendons from six ribs, and from five transverse
processes of the neck, and from these tendons being
in a direction which does not at all correspond with
the heads of the sacro-lumbalis. Indeed the longissi-
vol. i. a a
354<
muscles of the trunk.
mus 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. Perhaps it
would be better to consider it a continuation of
the accessorii ad sacro-lumbalem.*
Transver- CXXXIII. The TRANSVERSALIS COLLI is that wllicll
saiiscolli. Sabatier refers to the longissimus dorsi; but it is a
or. trans- distinct muscle arising, partly tendinous and partly
Tse Pof°5 fleshy» from the five upper transverse processes of
upper dor- the back ; lies betwixt the trachelo-mastoideus and
sai vert. ^he cervicalis descendens ; goes from the transverse
in trans, processes of the back to the transverse processes of
processes of r i
ail the cer- the neck, and has no more than a contused and
vie vert. irregular connection with any other muscle.
The quadratus 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 longissi¬
mus 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 backwards. The cervicalis descendens
co-operates with the trachelo-mastoideus, and others,
* 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 tendons fairly up
into the cervicalis descendens so far, that the slip is implanted
into the transverse processes of the neck. And, secondly, the feet
of 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 Sabatier has described it according to this
view.
muscles of the trunk.
355
which turn the head to one side ; and the cervicalis
descendens bends the neck to one side, botli the one
and the other being independent muscles.
These two muscles bring us to mention that intri¬
cate 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*
as the spinous, transverse, and oblique processes of
the vertebrae, and the bulging heads and angles of
the ribs : and each process, or at least each set of
processes, has its distinct sets of muscles and tendons.
1. There is one long continuity of muscular and
tendinous fibres going from spine to spine, and lying
on the side of the spinous processes along the whole
length of the back and neck. This is divided into
the spinalis cervicis and the spinalis dorsi.
°Z. 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 pro¬
cesses, whence it is named semi-spinalis dorsi.
3. There is a great mass lying all along the hollow
of the back, on each side of the spinous processes,
which, passing alternately from the transverse process
of one vertebra to the spinous process of the next
above, is of course split into many heads, but yet
having such connection as to give it the form and
name of a single muscle, the multifidus spinas.
4. and 5. There are yet smaller muscular fasciculi
which stand perpendicularly betwixt every two trans-
a a 2
3.5G
muscles of the trunk.
verse and every two spinous processes; thence they
are named inter-transversarii and inter-spinales.
semi-spin- CXXXIV. The spinalis cervicis is that which is
implanted into the spines of the cervical vertebrae;
but because it does not go from spine to spine, like
the spinalis dorsi, but from transverse processes to
spines, it has been named by Winslow semi-spinalis,
or. trans. or transvehso-spinalis colli. It arises from the
process of transverse processes of the six upper vertebrae of the
dorsai'vert.r back, and is inserted into all the spinous processes of
In. all the the vertebrae of the neck, except the first and last;
spinouspio- an(j extends the neck, or by its obliquity may con-
ccss or neck •/ j. %/ j
except the tribute to the turnings of the neck, or to bending it
1st and 7th. 0De sit|e#*
dor^alis CXXXV. The spinalis dorsi arises from two
o°r 2 u r SP^110US processes of the loins, and from the three
himb. vert. lower spines of the back, and passing two spines
3 lower untouched, it is implanted into all the spines of the
dorsal vert. , , . 1 rrn . r -
in. 8 or 9 back, except the uppermost. I his muscle is very
sup. dorsal slender and long, and consists fully more of tendon
the Iri>t than of flesh : it has five feet below, rising from the
lower spines of the back and loins ; and nine feet
above, implanted 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.
naiis'dorsi. CXXXVI. The semi-spinalis dorsi arises from
Or. trans. the transverse processes of the seventh, eighth, ninth,
process of anej. tenth vertebra? of the back, and is implanted into
the 7th,8 th, . -it - j
9th vert, of the six or seven upper dorsal spinous processes and
the back. jn{-0 t]le £wo ]asf. 0f tJle
S-eT? CXXXVII. The multifidus spin^e runs from the
upper dor- sacrum along all the spine to the vertebrae of the
lowest'cer-0 neck ; and is a comprehensive and true way oi'
vicai. describing many irregular portions of flesh, which
* The transveiisalis colli (vide p. 354.) is that which goes
from the transverse processes of the back to the transverse pro¬
cesses of the neck ; while this, the spinalis cervicis, goes from
the transverse processes of the back to the spines of the neck.
f This is of course the transverso-spinalis dorsi of
Winslow.
MUSCLES OF THE TRUNK.
357
authors have divided into distinct muscles.* It is a
continued fleshy indentation, from transverse process
to spine, through all the vertebras of the back, neck,
and loins.
It begins both tendinous and fleshy, from the
upper convex surface of the os sacrum, which is
rough with spines, from the adjoining part of the
ilium ; and in the loins, it arises from oblique pro¬
cesses : in the back, from transverse processes ; and
again from oblique processes, among the cervical
vertebrae.
Its origin in the loins is close to the spine, being
from the 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
processes, sometimes into the second, or even into
the third or fourth spine, above that from which the
bundle arises: for the tendons do not stop at that
spinous process which they first touch, but go up¬
wards, 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 spinas 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 proportioned to the neces¬
sity 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
* TrANSVERSO-SPINALIS LUMBORUM, SACER, SEMI-SPINALIS
INTERNUS, sive TRANVERSO-SPINALIS DORSI, SEMI"SPINALIS, S1VG
transverso-spinalis coeli, pars interna. Winslovv. Irans-
VERSALIS LUMBORUM, VlilgO SACER, I" RANS VERSALIS DORSi,
Transversalis COLLI.
A A 3
muscles of the trunk.
i i Til bones, and what little there is, .must con-
individual ^ general u seems ratlier intended to
Se(^\lf rate the lateral motions of the vertebrae than to
"induce them : when it acts, its chief use is either
to resist the spine being bent forward by a weight,
or to erect the spine.
CXXXVIII. The inter-spinalis colli, dorsi,
and lumborum, have varieties so little interesting that
they need hardly be described. The inter-spinales
colli are stronger, because the neck has many and
quick motions, and the bifurcated spines of the neck
give broader surfaces for these muscles. The inter-
spinales dorsi are almost entirely wanting, because
the spines of the back are close upon each other, and
the vertebrae are almost fixed. The inter-spinales
in the loins are rather tendons or ligaments than
proper muscles,
inter trans- CXXXIX. The inter-transversales are again
rsales' 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 bun¬
dles, where the motion is greatest, viz. betwixt the
atlas and dentata; and it is there that Albinus
counts his inter-transversales cervicis, priores,
laterales, &c. The inter-transversales 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-transversales are again strong,
for the lateral or twisting motions of the loins.
The muscles on the fore part 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.
Rectus CXL. Rectus internus capitis major. — There
maJ°r- are three muscles 011 each side, lying under the
oesophagus, trachea, and great vessels, flat upon the
fore part of the vertebrae ; and this is the first and
longest.
Or. 4 or 5 Althoughthis be called rectus, it is oblique, and
lower trans, running ratlier on one side; for it arises from the
CT.S. transverse processes of the five lower vertebra; of the
358
Inter-spi¬
nales.
muscles of the trunk.
359
neck, and it is inserted into the cuneiform process of
the occipital bone, just before the foramen magnum. CeS™ pr°
CXLI. Rectus internus minor. This is an Rectus
exceedingly small muscle. It lies immediately under
the rectus major: it arises from the forepart of or. fore
the body of the first vertebra, the atlas, and going pt^ofthe
(like the other rectus) obliquely inwards, it is inserted j^cipitai
into the occipital bone, near the condyle. bone near
CXLII. And the rectus capitis lateralis is t^t°unsdcyale"
another small muscle like the former, which arises lathis'! P
from the transverse processes of the first vertebra, Or. trans,
and is inserted into the side of the cuneiform pro- {^e^Tasf
cess of the occipital bone. It lies immediately under In. side of
the exit of the great jugular vein. form pro"
CXLIII. Longus colli. — This is the chief of longus
those muscles which lie upon the fore part of the colli-
neck; it is very long, arising from the flat anterior
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 Or. ist, bo-
uppermost vertebras of the back, from the flat part of ^^fdorsai
their bodies, and then from all the transverse pro- vert, and
cesses and bodies of the neck, except the three upper fndtranT
ones. It is inserted tendinous into the fore part of p«>c. of all
the second vertebra of the neck, where the opposite ^t^x-
large muscles meet in one point almost * ceptingthe
All these muscles, which lie thus flat upon the of
plain surface of the vertebrae of the neck, pull the dentata.
head and neck directly forwards; or when one acts,
they are of use in pulling it towards one side;
though I rather suppose this motion is performed by
the external muscles chiefly.
CXLIV. 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 vertebrae of the neck. But by its broad origin,
* The longus colli muscle is in part .covered by the rectus
major.
a a 4
360
MUSCLES OF THE TllUNK.
Scalenus
amicus.
Or. trans.
]>roc. of4th,
5 tli, and 6 th
eerv. vert.
In. 1st rib
near its
cartilage.
Scalenus
medius.
Or. trans,
proc. of all
the cerv.
vert.
In. large
portions of
1st rib.
Scalenus
posticus.
Or. trans,
process of
4th, 5th,
and 6th
ccrv. vert.
In. 2d rib.
and its very long insertion, it gives opportunity for
dividing it into several fasciculi; and accordingly it
has been so divided ; but these divisions arc entirely
modern, artificial, and unnatural. The ancients con¬
sidered it as one triangular muscle : Winslow divided
it into two, the primus and secundus ; Cowper into
three ; Douglas into four; and Albinus divides it
into five muscles. The ancients called it scalenus,
from its resemblance to the scalene 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 thorax 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 transverse 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 processes of all the ver¬
tebra? of the neck goes to the outer edge of the rib,
and extends along all its length. The posterior por¬
tion arises from the transverse processes of the fourth,
fifth, and sixth vertebrae. It is inserted into the
upper edge of the second rib, about an inch or more
from its articulation with the spine.
The first head is tendinous and fleshy at its inser¬
tion into the rib ; but the second and third heads are
tendinous, both in their origins and insertions.
The subclavian artery and the nerves pass in the
interstice betwixt the first and second portions.
The office of the scalenus muscle is to pull the
neck to one side, or to bend the head and neck for¬
ward, when both act; and when the neck is fixed
backwards, they may perhaps raise the ribs; for
asthmatics are observed to throw the head back¬
wards, in order to raise the chest with greater power.
361
OF THE MUSCLES OF THE ABDOMEN
AND OF THE DIAPHRAGM.
The abdominal muscles cover in the belly, con¬
tain the bowels, and take a firm hold upon the pelvis
and the trunk. The diaphragm, again, is a moving
partition betwixt the thorax 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 fasces
and urine, assist the womb in the delivery of the
child; and, with all these important uses, the abdo¬
minal muscles bend and turn the trunk, and fix it
for the stronger actions 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 straining, 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.
I. The outer oblique muscle, to which the names of
descendens, declivis, and major are added, be¬
cause it is the outermost of all the abdominal
muscles, because it is the largest, covering all the
side of the abdomen with its fleshy belly, and all the
fore part of the abdomen with its broad expanded
tendon; and it is called declivis, or descendens, be¬
cause its fleshy belly begins above, upon the borders
of the thorax, and because both its muscular and
tendinous fibres, which lie parallel to each other, run
obliquely from above downwards and inwards.
2. The obliquus internus is named from its
being within the first, and has the names of ascen-
muscles of the abdomen
dens vel minor superadded, because its fleshy belly
is smaller than that of the first, arises below chiefly
in the haunch-bone, and all its fibres go from below
upwards.
3. The transyersalis lies under all the others,
and next to the cavity of the abdomen, and has but
one name, which 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 fore part 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 upwards; 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.
obiiquus CXLV. The external oblique muscle arises from
descendens. the ribs, and, like all the others which arise from ribs,
Or. 8 inf. is a serrated muscle. It comes from the eight lower
nbs. ribS) by distinct fleshy tongues, one from each rib.
Four of these serrae are mixed with the indentations
of the serratus magnus anticus muscle, which goes oft*
in an opposite direction, and the rest with the origins of
the pectoralis major and latissimus dorsi; indeed some¬
times there is a mixing of the fibres of this muscle
with those of the pectoralis major. The origin of the
muscle, lying broad upon the border of the chest, 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, at the linea
semilunaris. Its flat sheet of tendon goes over the
fore part of the belly, till it meets its fellow exactly
in the middle, so that one half of the back part of
the abdomen is covered by its fleshy belly, and the
fore part by its tendinous expansion.
/n. i. linea The muscle meets its fellow in the middle of the
belly • and this meeting forms (along with the other
and of the diaphragm.
363
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 inclined to the
circular, whence it is named linea semilunaris. And, 2. spine of
finally, this muscle is implanted into the spine of the the ll,um-
ilium, fleshy about the middle of the ilium, tendinous
at the fore part or spinous process of the ilium, and
still tendinous into the whole length of that ligament, 3.- Po,Jpart
which extends from the spine of the ilium to the crest pubi os
of the pubes.
This is the whole of its insertions, viz. all the
length of the linea alba, from the pubes to the ster¬
num, the fore part of the spine of the ilium, and the
ligament of Poupart, which, though it is commonly
thought to be but the tendon of the external oblique
stretching from point to point, is, in truth, a distinct
ligament, independent of the tendon, and stronger
than it.*
CXLVI. Obliquus internus abdominis. — The obiiquus
chief part of this muscle arises thick and fleshy from intcriuls'
all the circle of the spine of the ilium, with its fibres
directed upwards. But, to be accurate, we must de- Or. 1. spine
scribe it as arising from the whole length of the spine 2™hc;,lllItn'
of the ilium, from the joining of the ilium and sacrum,
sacrum, from the spines of the sacrum itself, and
from the three lower spinous processes of the loins t; borum.
• 4 half of
and, lastly, it arises from nearly half of the ligament p0upart's
of the thigh, at its end next to the ilium ; but still Hg-
the chief belly is at the iliac spine. From that it
spreads upwards in a radiated form; the central
fibres only are direct, going across the abdomen to
the linea alba; the higher fibres ascend and go
towards the sternum, and the lower ones go obliquely
downwards to the pubes. Its flat tendon is like that
of the external oblique, and it is inserted into the
* See post, page 369.
f This origin from the spinous processes of the loins and sacrum
is a thin tendon, common with the serratus posticus inferior and
latissimus dorsi muscles.
364
muscles of the abdomen
In. 1. carti- cartilages of the seventh and all the false ribs, into
2^aniisif'es the ensiform cartilage of the sternum, and into the
of 7th and linea alba, through its whole length, and the os
^ false pubis>#
3.linea alba, CXLVII. The transversalis abdominis forms
Tranter'3* internal layer> it runs directly across the belly,
salis abdo- It arises fleshy from the inner surface of the seven
minis. lower ribs, where its digitations mix with those by
7 iowerribse, which the diaphragm arises; tendinous from the
2d, trans, transverse processes of the four lower lumbar ver-
lasTdorsai tebrae, and last of the back ; from the whole spine of
fourtranhe os ^um internally, and from apart of the Poupart
i^rocJseTof ligament. Upon the whole its origin is like that of
the lumbar the inner oblique muscle ; its fibres go across the ab-
7n. i. car- domen, and its tendon is inserted into the sheath of the
tiiagoensif. rectus, the whole length of the linea alba, cartilago
alba,"and ensiformis, and os pubis.
3. os pubis. The succession in which these three muscles arise
from the chest is this: the external oblique muscle
lies broad upon the outside of the chest, and so its
tongues mix with the tongues of the serratus anticus
magnus. 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, opposite
to where the tongues of the external oblique lie ; and
the diaphragm arising from the same ribs, mixes its
indigitations with the transversalis, so that Gaspar
Bartholin, observing this indigitation to be very
curious in the larger animals, believed the diaphragm
and transverse muscles to be but one great trigastric
or three bellied muscle, surrounding all the abdomen.
But the transversalis, with the other abdominal
muscles, are the antagonists of the diaphragm.
Rectus. CXLVIII. The recti muscles cover the abdomen
on its fore part, in a line from the pubes to the ster¬
num ; and they belong so equally to the sternum and
to the os pubis, that it is indifferent which we call
t * See the description of the sheath of the rectus muscle,
post, p. 366.
and of the diaphragm.
their origin, and which their insertion. The origin 0r• first.>
(as I should call it) of each rectus muscle is in the fruTribs'
sternum, is broad and fleshy, lies upon the outside of 2d> eusif.
the sternum, covering part of it, and all the xiphoid sSnum.
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 /n.sympliy-
is about four inches broad all down the abdomen, and S1S publs
terminates at the side of the symphysis pubis, with
a flat and pointed tendon about an inch in length,
and about an inch broad. This muscle is crossed at
intervals by four tendinous intersections, which divide
it into five distinct bellies. Commonly there are three
bellies above the umbilicus, and two below; but the
recti muscles are the least regular of all the muscles
of the abdomen. Vesalius, Albinus, and Sabatier
were thought to have found the recti abdominis ex¬
tending up to the throat. But it is now found that
Vesalius had only represented the muscles of a
monkey, or of a dog, which are very long, upon the
thorax of a human subject. Sabatier, upon revising
his notes, retracts what he had said : and Albinus
also is supposed to have seen only a production of
the mastoid muscle extending down the breast j for
irregularities of this kind have been found.
CXLIX. The pyramidal muscles are as a supple- pyramu
ment to the recti. There is a small neat pyramidal dalis-
muscle on each side, or rather a triangular muscle,
fleshy through its whole extent and length, with its
base turned towards the pubes, and its apex towards the^pubif
the umbilicus; so that its origin is in the crest of In. linea
the pubes, and its pointed insertion in the linea alba : alba>
and though the recti muscles have been supposed by
Massa to relate to the penis, or by Fallopius to belong
to the urinary bladder, their true use is only to assist
the rectus to draw down the sternum, and tighten
the linea alba, and so to give greater power to the
oblique and transverse muscles. The pyramidalis is
so irregular a muscle, that sometimes two are found
on one side, and none at all on the other. Some¬
times two on each other; sometimes there is but
muscles of the abdomen
one, and Very often they are wanting, the belly of
the rectus coming quite down to the pubes.
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.
1» The linea alba is the common meeting of all
the thin flat tendons, and therefore we call it their in¬
sertion, being the common point towards which they
all act; it is white, by the gathering of all the colour¬
less tendons.
2. The linea semilunaris is a line of the same
white appearance, 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 muscle, betwixt
the two other layers, is supposed to have its tendon
split into two thin sheets ; that the outermost sheet
adheres 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 ex¬
presses 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 to the semi¬
lunar line; that they immediately part and form this
sheath ; that the flat tendons of both the oblique
4
and of the diaphragm.
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 fore part, 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 muscles (or in their place the pyramidal
muscles) lie bare upon the viscera, lined only by some
scattered fibres of the fascia transversalis and the
peritonaeum.* And that this back layer of the sheath
is thinner and more delicate, and but little attached
to the back part of the rectus muscle, which is easily
raised in dissection, while the fore part of the sheath
adheres firmly to the fore part of the muscle, form¬
ing 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 intersections.
4. The umbilicus is that opening in the centre
of the abdomen, in the middle of the linea alba,
through which the nutritious vessels of the foetus
pass. The vessels have degenerated 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 ligament 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
* Cowper had never observed this but once, that the lower
part of the rectus was not lined by the tendon of the transversalis.
He concluded that in this instance it was a sporting of nature:
"so much a lusus naturae, that accidents like this might be the
cause of certain ruptures."
MUSCLES OF THE ABDOMEN
exceedingly wise, in placing 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 external oblique are, like the
muscle itself, oblique, running from above down¬
wards ; and the tendinous fasciculi are in some places
wider, a little disjoined from each other, and re¬
sembling 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 secures it from splitting farther up. But the
chief security of the ring is by the form of the open¬
ing ; 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
towards the pubes, like the fibres which form it,
and consists of two legs, or pillars of the ring, as
they are called; for the upper slip, which forms the
upper part of the opening, goes directly 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 liga¬
ment. ButCowper was not far from the truth, when
he said the bowels were prevented from falling down
by the obliquity of the spermatic passage. The
spermatic cord is flat and spread out when it begins
to, pass down through the abdominal walls, and it is
only when it has emerged from this proper ring that
it assumes the round and cord-like form. Besides,
it comes out under the transversalis muscle con¬
siderably higher up and more towards the ilium than
the ring, and in its further descent it splits the fas-
10
and of the diaphragm.
369
ciculi of the internal oblique muscle, and carries one
of these fasciculi along with it, which constitutes the
cremaster muscle. First its veins and arteries are
gathered together, then it is joined by the vas deferens,
and, finally, it is embraced by the cremaster muscle;
and thus perfected^ as it were, it glides obliquely
through the ring of the external oblique muscle.
Where it comes out it is covered by the fascia super-
ficialis, a process of which goes down upon the
cord. When the cord is passing under the trans-
versalis muscle it passes the fascia transversalis, the
fibres of which are strong upon one side : the cellular
membrane too here is dense, and, although there be
in the natural condition of the parts no proper ring,
yet when a r-upture takes place, a portion of the
peritonaeum is thrust through the spermatic passage,
and presses the cellular membrane and fascia so
together, that a ring is formed ; this is what is meant
by the internal ring.
CL. The CREMASTER MUSCLE of the TESTICLE, Cremaster.
which is a thin slip of fibres from the internal Or.i.Wer
oblique muscle of the abdomen, designed for sus- tem.obHq"
pending the testicle, and for drawing it up, is very 2. theos
thick and strong in the lower animals, as in bulls, ica
dogs, &c. ; is easily found in man, but not always, vaginalis,
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 liga- Crural
ment, and not merely the tendon of the external arcb*
oblique, rounded and turned in. It passes from the
ilium obliquely across to the pubis. It receives the
external oblique muscle, for the tendon is implanted
into it* Part of the flesh of the internal oblique
muscle and transversalis arise from the outer end of
the ligament. It forms an arch over the psoas and
* This ligament of the thigh is named also the inguinal lig¬
ament ; the crural arch; the ligament of Poupart; the
ligament of FaLLOPIUS, &C.
vol. i. r b
muscles of the abdomen
iliacus internus muscles, where the crural artery vein
and nerve pass out, and it is tied down at both sides
of the passage for the vessels by the fascia of the thigh.
But this ligament requires a more particular descrip¬
tion. It appears outwardly to have a round edge,
but in fact it is here turned in, its lower margin
shelves inwards, and at the pubic end it spreads
horizontally upon the os pubis, as far as to the brim
of the true pelvis, and the spermatic cord lies upon
it. The angle where it turns inwards is attached to
the fascia of the thigh, while the edge, which is turned
in, is continued inwards under the cord in the form of
a fascia or ligament, and is connected with the linea
ilio-pectinea. So this ligament of the thigh is said to
have three principal attachments to bone, viz. the an¬
terior superior spinous process of the ilium, the spine
of the os pubis, and the linea ilio-pectinea. The
attachment of the ligament to the fascia of the thigh
demands a little more attention. When the glands and
fat of the groin are taken away, the connection of the
fascia of the thigh and the Poupart ligament presents
the form of an inverted funnel; and if an attempt be
made to pass the finger to the bottom of it, towards
the abdomen, it is stopped by a strong net-work of
fibres : the meshes of this net-work permit the lym¬
phatics of the thigh to pass upwards, whilst the
stronger processes of the fascia take the form of
a crescent. Thus, besides the proper strong Poupart
or inguinal ligament, there is an arch or crescent
formed of less dense and shining substance, which
goes down from the edge of the ligament, and ter¬
minates on each extremity in the fascia of the thigh.
This is the part iftider which the crural hernia comes
out; round which, indeed, the tumour turns, and it
is the sharp edge of this crescent which nips, and
causes the strangulation of this kind of hernia.
It often happens, that in vomiting, in violent
coughing, in straining at stool, or in lifting heavy
weights, the natural openings are forced, and the
bowels descend. The umbilicus is very seldom
forced by sudden exertion, for it is a very firm ring ;
13
and of the diaphragm.
371
but it is slowly dilated in pregnancy, and hernia of
the navel is infinitely more frequent with women
than with men. The opening of the 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 straining ; but women are safer from this
kind ot hernia, because the round ligament of the
womb is smaller than the spermatic cord, and the
ring in them is very close. — Abdominal ventral
hernije are those which come not through any natural
opening, but through the interstices of' the muscles,
or their tendons ; sometimes hernia follows a wound
of the abdomen ; for a wound of the abdominal
muscles may not heal so neatly as not to leave some
small interstice, through which the bowels protrude.
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 hernias 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 here¬
ditary 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
openings so particularly wide, that upon the slightest
coughing or crying, herniae came down at every
possible 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.
CLI. The diaphragma is a Greek word, trans- diaphragm,
lated 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 abdomen ; and not
only is the middle raised into a vaulted form, but its
obliquity is such, that though its fore part be as
high as the sternum, its lower and back part arises
near the pelvis from the lowest vertebra of the loins.
B B 2
372
MUSCLES OF THE ABDOMEN
Greater
muscle.
Or. 1. xi¬
phoid cart.
2.seventh
and all the
false ribs,
3. the lig.
arcuatum.
In. cordi-
form ten¬
don.
Lesser
muscle.
Or. 2d, 3d,
and 4th
lumb. vert.
In. back
part of cor-
diform ten¬
don.
It is a circular muscle, which is fleshy towards its
borders, and tendinous in the centre ; which is con¬
vex 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.
The diaphragm arises, by one broad fleshy attach¬
ment, from all the borders of the chest, forming the
upper or greater muscle of the diaphragm ; and it
arises below, by many small tendinous feet from the
fore part of the loins, which meeting, form what is
called the lesser muscle of the diaphragm. 1st, The
great or upper muscle arises, first, from under the
xiphoid cartilage, and from the lower surface of the
sternum. 2dly, From all the false ribs ; from the
cartilage of the seventh, 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 intermix with those of the transverse muscle
of the abdomen. 3dly, From the tip of the twelfth
rib to the lumbar vertebras, there is a ligament
extended, which, going like an arch over the psoas
and quadratus lumborum muscles, is named liga-
mentum 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 liga-
mentum arcuatum ; and, in short, from all the
borders of the chest, from the xiphoid cartilage
quite round to the vertebrae of the loins.
2. The lesser muscle of the diaphragm, which
arises from the spine, begins by four small slender ten-
dinousfeet on each side. The first of these, thelongest
one, arises from the second vertebra above the pelvis:
it goes from the flat fore part of its body, and adheres
to the fore part of the third and fourth lumbar verte¬
brae as it mounts upwards. The second rises from
the third vertebra, but farther out towards the side
and of the diaphragm.
of the vertebra. The third arises from the side of the
fourth vertebra. And the fourth tendon of the dia¬
phragm arises from the transverse process 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 vertebra; by
four tendinous feet, flat and glistening, and adhering
closely to the shining ligament with which the bodies
of the vertebras 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 then
joining, 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
determined in its shape by the extent of these fleshy
bellies ; for the great muscle above almost surrounds
the central tendon. The smaller muscle below meet¬
ing it, the two divisions give it a pointed form
behind ; the tendon has the figure of a trefoil leaf,
or of the heart painted upon playing cards. The
middle line of this tendinous centre is fixed by the
membrane which divides 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 inverted
basin : their convexity reaching within the thorax,
quite up to the level of the fourth true rib: the
proper centre of the diaphragm is fixed by this con¬
nection with the mediastinum, that its motion might
not disorder the actions of the heart, which rests
upon this point, and whose pericardium is fixed to
the tendon : but the convexity of either side descends
and ascends alternately as the diaphragn 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 mus¬
cle behind ; and of the triangular tendon, as the
centre betwixt them: and, both in its fleshy and
tendinous parts, it is perforated by several vessels
muscles of the abdomen
passing reciprocally betwixt the thorax and the
abdomen.
First, The aorta, or great artery of the trunk,
passes betwixt 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 dia¬
phragm, a little above this, and to the left side : its
passage is through the lower fleshy belly, and through
the most fleshy part of the diaphragm : and the mus¬
cular fibres of the crura diaphragmatis first cross
under the hole for the oesophagus ; then surround
it; then cross again above the hole; so that they
form the figure of 8 ; and the oesophagus is so ap¬
parently compressed by these surrounding fibres,
that some anatomists have reckoned this a sort of
sphincter 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 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 various fasciculi of this muscle, meeting and
crossing each other with a confused interlacement,
which Albinus has been at much pains to trace, but
which Haller reports much more sensibly : " Intri-
cationes variae et vix dicendae irregular and con¬
fused, crossing chiefly at the openings, and espe¬
cially 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 peritonaeum, 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 opening, all
round the vein.
The chief use of the diaphragm is in breathing,
and in this office it is so perfect, that thougli there
be a complete anchylosis of the ribs (as has often
AND OF THE DIAPHRAGM.
3J5
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 becomes
plain, the thorax is enlarged, and by the mere weight
of the air, the lungs are' unfolded, and follow the dia¬
phragm. No vacuum is ever found betwixt the dia¬
phragm and the lungs : but the lungs follow the ribs
and diaphragm as closely as if they adhered 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 won¬
derful combination of actions conspiring to one end,
as cannot be even enumerated here. But the alter¬
nate action and re-action of the abdominal muscles
draw in and expel the breath, promote the circula¬
tion, and gently agitate the bowels, while their more
violent actions discharge the faeces and urine, and
assist the womb ; and vomiting, yawning, coughing,
laughing, crying, hiccup, and the rest, are its stron¬
ger and irregular actions. The diaphragm might
well be named by Haller, " Nobilissimus post cor
musculus." And Buffon, who affected the character
of anatomist with but little knowledge of the human
body, might mistake its central tendon for a nervous
centre, the place of all emotions, 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.
B B 4
376
muscles of the parts of
THE MUSCLES OF THE PARTS OF GENE-
RATION, AND OF THE ANUS, AND
PERINEUM.
The muscles of the perinaeum and parts of gene¬
ration follow the division of the abdominal muscles
more naturally than any other. On looking to the
skeleton, we see that the viscera of the abdomen and
pelvis would fall out from the lower opening, if this
space was not guarded in a particular manner. It is
therefore closed, 1. by fascia ; 2. by muscles, now
to be enumerated; and 3dly, by fat and cellular
texture ; the nature and quantity of which is a mat¬
ter of no mean interest to the surgeon.
Before reading the account of the muscles of the
jDerinaeum, the reader should peruse that part of the
last volume which treats of the structure of the
penis, &c.
Fascia, or aponeurosis. — Before dissecting the
muscles of the perinaeum, the student should exa¬
mine that web of membrane which covers them. It
comes across from the tuberosity and ramus of the
ischia, and, running forward, terminates at the scro¬
tum. It is a subject very important to the operating
surgeon.
erector CLII. The erector penis is a delicate and
penis' 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
Or. tuber, seen of their proper length and form. The erector
oftiie 0f each side rises by a slender tendon from the
/T'sheath tuberosity of the os ischium. It goes fleshy, thin,
of the ci us and flat, over the crus penis, like a thin covering,
pems. en(js -n a deiicate anj tendon, upon the crus
penis, about two inches up ; and the tendon is so
thin and delicate, that it is hardly to be distinguished
from the membrane of the cavernous body.
The erectors lying thus on the sides of the penis,
have been called collaterales penis, or ischio-
generation, anus, and perineum.
377
cavernosi, from their origin in the ischium, and
their insertion into the cavernous bodies.
CLIII. The transversalis perin^i is often named J[.ansver"
transversalis penis ; but its origin being in the tube- or1S'tuber
rosity ot the os ischium, by a delicate tendon, and its of the
insertion into the very backmost point of the bulb of lschlum-
the urethra, where it nearly touches the anus, and ^™on
where there is a meeting of several muscles, its union,
course is directly across the perinaeum, and its rela¬
tion 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 transversalisperinjei alter.*
This transverse muscle may, by bracing up the
bulb to the arch of the pubis, have some effect in
stopping the vein 011 the back of the penis, and so
producing erection ; but its chief use must be in
preventing the anus from being too much protruded
in discharging the faeces, and in retracting it when
it is already protruded.
CLIV. The ejaculator muscle is not a single ejacuktor
muscle, as it is often described. It is manifestly a
pair of muscles surrounding the whole of the bulb of
the urethra. They arise on each side from the side the body°f
of the bulb, and crus of the penis, and from the andbuib,
triangular ligament of the urethra. From their ^^nang'
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
* There is a 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 pro¬
fundus ; it has exactly the same origin and insertion with the other,
but lies deeper. At first view it appears to be part of the levator
ani, but the fibres run directly across, while those ot the levator
run in a descending direction.
■
378 muscles of the parts of
in. middle and tendinous line, corresponding with the outward
and'spongy line or seam of the perinaeum. This line distinguishes
body. ° 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 circular 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 upon the crus penis of its own side, a
little higher than the insertion of the erector penis.
We know and feel its convulsive, involuntary action
in throwing out the seed ; and we are conscious that
we use it as a voluntary muscle in emptying the
urethra of the last drops of urine.
fni.hncter CLV. The sphincter ani muscle is a broad
osc c circular band of fibres, which surrounds the anus.
Cygis.S c°c It arises from the point of the os coccygis behind.
in.i. round It sends a neat small slip forwards, by which it is
gheSpongy attached to the back part of the ejaculator muscle ;
body of the but the great mass of the muscle is inserted into
^commTn common angle of union of the ejaculator, trans-
angle of versales, and this muscle. It is of a regular oval
umon. 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 external,
or cutaneous ; what they describe as the internal one,
is merely the circular fibres, or muscular coat of
the intestine, strengthened considerably towards the
anus, but not a distinct muscle. Its effect is to shut
the anus.
Levator CLVI. The levator ani muscle is described as
&Or i o$ a Pa*r musc^es^ one from each side; but it is
pubis, thy. properly one broad and thin muscle, which arises
from the internal surface of all the fore part of the
and body of pelvis, and, from its breadth, it has been named
theischium. musculus ani latus. It continues its origin from
the internal surface of the pubes, from the edge of
the foramen thyroideum, from the thin tendinous
GENERATION, ANUS, AND PERINEUM.
379
sheath that covers the obturator interims and coc-
cygeus muscles, and from the body and spine of the
os ischium. It grows gradually smaller, as it goes
downward to surround the anus. So it is inserted yaenrge
into the circle of the anus, into the point of the os La a*!?*
coccygis, and is mixed with the sphincter ani muscle. |wo last.
The whole pelvis is lined with it like a funnel, or oswccygis!
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 bladder 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 faeces, and supporting it, so as to prevent its
being protruded. Thus, it is not for shutting the
anus, as some have supposed, but is the direct an¬
tagonist of the sphincter ani muscle. By enclosing
the bladder, the levator ani acts upon it also; for
the neck of the bladder passing 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 flow¬
ing. It is as a sphincter to the bladder, which pre¬
vents our passing the urine and faeces at the same
moment. By surrounding the lower part of the
bladder, and enclosing the prostate gland, and the
vesiculae 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 vesiculae, or to compress the gland, pulling
upwards at the same time, so as to press the back of
the penis against the pubes, to maintain the erection,
and to assist the accelerator muscles. By enclosing
the bladder, vesiculae, prostate, and anus, this muscle
produces that sympathy among the parts, which is
often very distressing, as in gonorrhoea, the stone in
the bladder, constipation, piles, and other diseases of
these parts ; for piles, constipation, or any cause
which may excite the action of the levator muscles.
380
muscles of the parts of
will cause erections, a desire to pass the urine, and
an obstruction in the discharge of it.#
coccygeus. CLVII. The musculus coccygeus is a thin, flat
muscle, which arises by a narrow point, from the
the ischium inside of the pelvis, at the spine of the os ischium ;
and the is implanted, expanded and fleshy, into the whole
— f tength °f os coccygis ; can be useful only by
the os pulling up the point of the os coccygis; which is
coccvgis. just eqUivaj[ent 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 trans-
versales perinaei come across the perinaeum from
either side; and the levator ani muscle comes down
to meet the sphincter, so that the sphincter ani, the
levator ani, the transversalis perinaei, and the ejacu¬
lator 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 unskil¬
fully cut in performing lithotomy, 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 passes by the side of
the erector muscle, need not touch it, or touches it
slightly, and by a sort of chance : it must not touch
* There is a muscle described by Mr. Wilson, as a levator,
or compressor urethrae. The origin of this muscle is from the
arch of the pubes, and its fibres run round the membraneous part
of the urethra, being inserted on the lower part into each other :
it is situated between the Cowper's gland and the levator ani,
being separated from 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 describes it, it is necessary
to sacrifice several of the fasciae.
generation, anus, and perineum.
381
the ejaculator muscle ; for whoever says he cuts the
ejaculator, cuts too high, and performs his operation
ill. * After the first incision we get deep into the
pelvis, and cut the levator ani. The surgeon does
not observe these muscles, on account of any danger
which may attend wounds of them, but takes them
as marks for the true place of his incision; and a
good operator will be careful to have them fairly cut,
that they may be no hindrance to the extraction of
the stone, t
We find, of course, a difference in the muscles in
the female perinaeum. 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 inserted into the crura penis.
The next muscle is the sphincter vaginas, which is a
large muscle, taking an origin from the sphincter
ani and posterior side of the perinaeum ; it is inserted
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 dif¬
ference, except that they are attached to the vagina
instead of the penis.
The muscles of the female perinjeum, are,
Erector clitoridis. — Or. From the ramus of
the os ischium: in its ascent it covers the crus of
the clitoris, as far up as the os pubis.
In. Into the upper part of the crus, and body of
the clitoris.
* Those anatomists who describe the origin of the ejaculator to
be from the ramus ischii object to this.
i Detrusor Urinae is but the muscular coat of the bladder;
the Sphincter Vesica; is but a denser fasciculus 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 that part of the system which describes the
organs and viscera.
382
muscles moving the thigh-bone.
Use. To erect the clitoris, by pushing the blood
into its cavernous substance.
Sphincter vaginae. — Or. From the sphincter ani
and from the posterior side of the vagina, near its
external orifice, opposite to the nymphae, and covers
the corpus cavernosum vaginae.
In. Into the body, or union of the crura clitoridis.
Use. Contracts the mouth of the vagina, and by
compressing the corpus cavernosum, pushes the
blood into the clitoris and nymphae.
Transversalis perin^i. — Or. As in the male,
from the fatty cellular membrane which covers the
tuberosity of the os ischium.
In. The upper part of the sphincter ani, and
into a white tough substance in the perinaeum,
between the lower part of the pudendum and anus.
Use. To sustain the perinaeum.
Sphincter ani. — Or. As in the male, from the
skin and fat surrounding the extremity of the rectum.
In. Into the white tough substance in the peri¬
naeum, and below, into the front of the os coccygis.
Levator ani. — Or. As in the male, within the
pelvis. It descends along the inferior part of the
vagina and rectum.
In. Into the perinaeum and sphincter ani.
MUSCLES 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
iliacus internus, come from within the pelvis, at
its fore part, 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
muscles moving the thigh-bone.
383
muscles come from the lower and fore part of the
pelvis, as the pectinalis, triceps, and obturator
externus, which arise from the arch of the os pubis,
and go down to be implanted into the linea aspera
and lesser trochanter ; and, they pulling the thigh
towards the body, are called the adductors. Others
arise from the sacrum and back part of the pelvis,
as the glutei, which, coming directly forwards to be
implanted into the greater trochanter, pull back the
thigh; and a fourth set coming also from the in¬
ternal 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. The PSOAS MAGNUS, ILIACUS INTERNUS, PECTI-
NEUS, TRICEPS, OBTURATOR EXTERNUS, which, COming
from before, are inserted into the line of the minor
trochanter and the femur, and bend the thigh.
2. The GLUTiEI, GEMINI, PYRIFORMIS, OBTURATOR
internus, and quadratus, which come from behind,
are implanted into the line of the great trochanter,
and extend the thigh ; and it hardly need be remem¬
bered, that as, when the arms being fixed their
muscles raise the weight of the body, as in climbing
or in turning over a bar, by grasping with the hands,
so the muscles of the thigh move that thigh only
which is loose, and free from the weight of the body,
while the muscles of the other thigh, which is fixed
by the weight of the body, move not the thigh, but
the trunk upon the thigh ; so that our walking is
performed not so much by the muscles of the thigh
moving the limb, as by their moving the pelvis, i. e.
rolling the trunk upon the limb.
MUSCLES MOVING THE THIGH.
1. The thigh is moved backwards and outwards.
By the glutaeus maximusn which are C linea aspera,
medius, > implanted trochanter major,
minimus, J into the I top of trochanter.
384
MUSCLES MOVING THE THIGH-BONE.
2. The thigh is moved backwards, and rolled upon
its axis,
By the pyriformis, are fr00t of the trochanter,
gemini, implant- )
obturator externus, > ,r. . <
i ed into )
internus, I thg :
quadratus, J v betwixt the trochanters.
3. The thigh is moved forwards, and the toe
pointed outwards,
By the psoas magnus, ^ vvhich are T troc^anter ni'nor»
iliacus internus, t inserted J
pectinalis, f intQ the ^ linea aspera.
triceps, J V
In the dissection of these muscles, a sort of arti¬
ficial arrangement may be made of the muscles of
the thigh, by taking off the fascia, the fascialis
muscle, the sartorius, and the gracilis, and then
dividing the remaining twelve muscles into groups
of four; as, four inserted into the patella, to extend
the leg ; four to bend the leg, and four adductors to
bring the thighs together.
OF THE FASCIA OF THE THIGH.
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 supported
by them. The tendinous fascia of the thigh arises
chiefly from the spine of the ilium, and from the
Poupart ligament. Every fascia has something added
by each muscle, and takes a new increase and adhe¬
sion at each bone which it passes. It is always
strengthened by adhesions to joints, and comes
down from them thicker upon the muscles below ;
and so this fascia of the thigh, which arises chiefly
from the spine of the ilium, descends, covering all
the muscles of the thigh: it sends partitions down
to the linea aspera and trochanters; it has a new
adhesion and a new source of tendinous fibres at the
knee; it adheres most remarkably at the inner side
7
muscles moving the thigh-bone.
385
of the tibia, and then descends to the calf; it covers
all the leg, and is again reinforced at the ancle ; and
this is ajuster history than the common 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 tendon of the musculus
fascialis, and which is at the same time connected
with the capsular ligament of the femur and with
the trochanter; and so the muscle called fascialis
lies betwixt the two plates of the fascia; and as the
fascia, at this part, takes at least a reinforcement from
the capsular ligament and from about the trochanter
major, the fascialis muscle may be said to be inserted
into the trochanter.
So this great tendinous fascia has these connec¬
tions : the crest of the ilium; the ligament of Pou-
part, 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 sacrum ;
the ligament of the joint, the great trochanter ; and
the linea aspera, all the way down to the knee, where
its last adhesion is very strong, and from whence it
comes off again, much strengthened. It is thicker
on the outer side and back part, and very thin on
the inner side of the thigh ; it splits to embrace the
sartorius, and it dives with perpendicular divisions
among the muscles of the thigh, and is even con¬
nected with the sheath of the great vessels.
The use of- this tendinous membrane has been
quite overlooked. While it gives attachment to
muscles, and embraces them like the other fasciae, it
performs a much more important office. Its connec¬
tions enable us to throw the weight of the body on
one limb, and, as it were, to hang the weight of the
body on the pelvis, independent of muscular exer-
vol. i. c c
386
muscles moving the thigh-bone.
tion. When a soldier, from a constrained and stiff
position in the ranks, is standing equally on both
legs, his joints are kept straight by muscular exer¬
tion ; but when at the words, stand at ease, he
throws himself on one leg, and relaxes the other,
the body, supported by the spine, and the spine by
the pelvis, weighs behind the centre of the aceta¬
bulum ; then the fore part of the ilium rises; the
fascia is stretched; the muscles of the thigh become
braced ; the patella is drawn up ; the knee grasped
by the membranes, and the leg extended. The
whole limb is thus embraced and extended by the
weight of the body thus operating on the fascia, to
the relief of muscular exertion.
This is a very beautiful mechanical provision for
saving muscular power; and while the body rests
alternately on one leg or the other, it throws the
whole body into a position of ease and grace. But
when there is weakness, as in young people, or when
there comes to be a habit of standing on one foot,
the necessary obliquity of the pelvis produces an
obliquity of the spine, and at last permanent distor¬
tion of the spine. *
In a surgical point of view the fascia of the thigh
is a subject of the utmost consequence, as it regards
hernia, aneurism, and abscess.
Fascialis. CLVIII. The fascialis muscle. — This muscle is
Or. sup.ant. named also tensor vaginae femoris. It arises from the
iHum.°fthe upper spinous process of the ilium, i.e. from the
fore part, or very point of its spine, by a tendon of
about an inch in length. It is very small at its
origin, and at its termination. It is thick and fleshy
in the middle, swelling out; it extends downwards,
and obliquely backwards, almost to the middle of the
in. fascia thigh, and there it terminates obliquely, betwixt the
two lamellae of the membrane to which it belongs.
Its use is chiefly as an abductor, and to make
the fascia tense, to prepare the muscles for strong
* The consequences of this obliquity of the pelvis in young
people is very fully treated of in Mr. Shaw's folio work on the
Distortions of the Spine.
MUSCLES MOVING THE THIGH BONE.
387
action; and, perhaps, by its adhesions about the
trochanter, it may have some little effect in rolling
the thigh, so as to turn the toes inwards, and oppose
the Gemini.
CLIX. Psoas magnus. — This and the following Psoas mag-
muscle come from within the body to move the mis'
thigh forwards. This is a very long and fleshy
muscle, of considerable strength, of constant use,
perpetually employed in moving the thigh forward,
or in supporting the pelvis upon the thigh-bone, so
as to preserve the equilibrium of the body.
The psoas is a large round muscle, very strong,
of great length, filling up all the space upon either
side of the spine, and bounding the pelvis at its
side. It comes from under the ligamentum arcua-
tum of the diaphragm ; for it arises first by its Or. i. body
uppermost head from the last vertebra of the back,
then successively from each of the vertebrae of the 2. bodies
loins. It sticks close to the lumbar vertebrae; for ^esT'of
it arises not only from the transverse processes, but ail the lum-
from the sides of the bodies. These heads do not barvert-
appear, for they are covered by the body of the
muscle, which goes down thick and round, till it
reaches the sacro iliac symphysis, and then being
united to the internal iliac muscle, they descend
through Poupart's ligament. It is inserted into the ^-trochan-
lesser trochanter of the thigh-bone, and into the body er minou
of the bone, a little below the root of the process,
CLX. The psoas parvus does not, like this, Psoas par-
belong to the thigh, but is a muscle of the loins,
which arises along with this one from the last ver- ^r'^ert
tebra of the back and the first of the loins, and 'i or 2
It is a small and delicate muscle, ends in a slender of loins-
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 implanted into the ^ br|m of
brim of the pelvis, into the os ilium near the place tlepeviS-
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 is said to be
more frequently found in women than in men; in
c c g
388
MUSCLES MOVING THE TIIIGII-BONE.
both, it often is not to be found: but sometimes, m
strong and big men, three psoas muscles have been
found, lhis muscle is so small, and so powerless,
in regard to the motion of the trunk, that looking
to the connection of its tendon with the Poupart
ligament, I regard it rather as closing the opening
to the thigh, and strengthening the abdominal ten¬
dons in their insertion into the os pubis.
Iliacus in- . CLXI. The iliacus internus is a t ck, very
fleshy, and fan-like muscle, which occupies the whole
concavity of the os ilium.
Or.i.inter- Its origin is from the internal lip of the crista ilii
the crista and transverse process of the last lumbar vertebra;:
iiii, 2. the it adheres to all the concave surface of that bone,
fore^an of down to the brim of the pelvis ; to the fore part of
the same, the bone under the spinous process ; and to a part
pro. of the also of the capsular ligament of the joint: all its
last lumb. radiated fibres are gathered together into a tendon
VCrt r* r?
' , at the ligament of Poupart. This tendon is longer
In, trochan-
ter minor, on the lower than on the upper surface : for below,
it slides on the pubes as upon a pulley, and con¬
tinues 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 ligament 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, whilst the psoas, as arising from the
vertebras, is more particularly for supporting the
body.
We must not pass from the study of these muscles,
without paying attention to the iliac fascia, which
is very important in a surgical point of view.
Although the term origin of the fascia is used in
description, it is incorrect; for there is no resem¬
blance betwixt the connections of fascia with the
spines of bone, and the origin of muscles from bone.
From the inside lip of the spine of the ilium, a strong
tendinous membrane or fascia stretches over the
7
muscles moving the thigh-bone.
/
389
iliacus internus muscle. This fascia continues up¬
wards over the psoas magnus, and may be traced
over the lateral parts of the lumbar vertebrae. Down¬
wards and forwards it connects itself with the inner
edge of the Poupart ligament, from which it may be
traced into the aponeurosis, which lines the inside
of the muscles of the abdomen.
This fascia extends betwixt the iliac and psoas
muscles and the peritoneum ; and by its connections
to the os ilii and os pubis, and to the tendon of the
abdominal muscles, at the part called Poupart liga¬
ment, it completes and secures the walls of the ab¬
domen. But if matter should be formed by the side
of the vertebrae, or in the cellular membrane, which
is around the psoas muscle, it has an easy descent
behind this fascia, and under the Poupart ligament,
into the thigh, by a canal posterior to that which
admits the descent of hernia.
We return to the muscles of the thigh.
CLXII. The PECTINEUS 01' PECTINALIS, SO named I'ectineus.
from its arising at the pecten or os pubis, is a broad,
flat, square muscle : it lies alongside of the last
described muscles, and is inserted with their common
tendon. It arises flat and fleshy from that part of Or. upper
the os pubis which is bounded on the upper part by p"?tf^etlie
the linea ileo pectinea, and on the lower by a ridge os pubis,
running from the tuberous angle of the pubes to the tmmetu
upper part of the acetabulum, and is implanted into in linea
the linea aspera, immediately below the trochanter
minor, by a tendon flat and long, pretty nearly of clianter
the same extent and shape with its origin. minor-
This muscle lies immediately under the skin and
fascia lata : and by its bending round under the
thigh-bone, it has three actions ; to close the knees
together ; to pull the thigh forward ; to perform
rotation, turning out the toe ; and, in certain positions
of the limb, it will pull the thigh back, assisting the
extensor muscles.
CLXIII. The triceps femoris is a broad flat
muscle, with three heads, arising from the os pubis, also
in part from the ischium, and inserted into the whole
c c 3
390
muscles moving the thigh-bone.
Adductor
longus.
Or. upper
and fore
part of the
os pubis
and liga¬
ment.
In. middle
and back
part of the
Jinea
aspera.
Adductor
brevis*
length of the linea aspera down to the condyle, and
serving for pressing the knees together; when the
thigh is behind, they must assist in bringing it for¬
ward ; when the thigh is forward, they must carry
the body perpendicularly over the thigh-bone, so
that, besides being adductors, these muscles are in
incessant operation in walking.
The triceps consists of three heads, which lie in
different layers, one above the other; and have so
little connection among themselves, that they have
been more commonly, and I think properly, de¬
scribed as three muscles. These three parts of the
muscle are, indeed, for one common use: but they
are of very different forms ; for they do not even lie
on the same plane: one is long, another shorter by
one half, a third larger than both the other two ; so
that they have been commonly described under the
names of adductor primus or longus ; adductor
SECUNDUS or BREVIS ; ADDUCTOR TERTIUS 01* MAGNUS.
1. The adductor longus is the uppermost layer ;
its border (for it, like the pectinalis, is a flat muscle,)
ranges with the border of the pectinalis. It arises
from the upper and fore part of the os pubis and the
ligament of the symphysis by a short roundish ten¬
don, very strong : it swells into a thick fleshy belly,
not round, but flattened; the belly grows flatter as
it goes down towards the thigh-bone; it ends in a
flat and short tendon, which is inserted into the
linea aspera in all its middle part, viz. about four
inches. Thus, the muscle is of a triangular form,
with its base in the linea aspera, and its apex on the
os pubis. Its head or origin lies betwixt the pecti¬
nalis 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 ; for as
the first layer consists of the pectinalis, adductor
longus, and gracilis, this layer consists of the obtu¬
rator externus, adductor brevis, and adductor mag-
muscles moving the thigh-bone.
391
nus. I he adductor brevis is exceedingly like the Or.ospubis
former, in rising near the symphysis pubis, by a ]b^tow the
thick and flattened tendon, swelling like it into a In. linea
strong fleshy belly ; like it, it grows flat, and is in-
serted by a short flat tendon into the inner trochanter the lesser
and upper part of the linea aspera. But it differs in I^com.
these points : that it is less oblique, for this muscle mencement
being shorter goes more directly across betwixt the °e?tbVof
pelvis and the thigh ; that it is placed higher than the next,
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 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 fore
part of the os pubis, from the ramus just under the
crest, so as to be immediately under the head of
the longus.
3. The adductor magnus, the third head of the Adductor
triceps, is a very long and flat muscle, lying behind 0r the ^a_
the other heads. It arises by a short tendon, just mus pubis,
under the tendon of the adductor brevis ; it con- a^l[^mus
tinues to have a fleshy origin all down the ramus of the /n. iinea
pubes and the ramus ischii to the tuber, i. e. from the ™Pera>and
flat edge of the thyroid hole. From this broad origin, dyleofthe
it goes to be implanted into the thigh-bone the whole femur-
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 descend, the lower part of the
muscle following that rough line which leads to the
condyle, and the last fibres of all are implanted, 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 tiiceps, to get
c c 4
39L2
muscles moving the thigh-bone.
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,
obturator CLXIV. The obturator externus is named after
extemus. obturator ligament, from which it arises. The
ligament and the muscles shutting up the foramen
thyroideum are named obturators, and this is some¬
times named rotator femoris extrorsum, from its
Or. crus turning the thigh outwards. It arises from the ramus
?schii,'mem- the ischium and os pubis, where they form the
branaobtu- 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
in. cavity inserted into the root of the great trochanter. It
trochanter l)u^s the thigh forwards, but is more peculiarly a
major. rotator of the thigh. This muscle is of the second
layer, and the succession of all the muscles is this ;
the upper layer consists of the psoas and iliacus,
where they come out from the abdomen, of the
pectinalis, and of the long head of the triceps ; the
second layer consists of the short head of the triceps;
and the third layer consists of the obturator externus
at the upper part, and the triceps magnus, or third
head of the triceps, all down to the condyle.
GLUTiEi. — There are three glutsei muscles, each
under the other, and each smaller than the muscle
which covers it. The first, arising from the back
part of the ilium, the back of the sacrum, and the
muscles moving the thigh-bone.
393
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.
CLXV. The glutjeus maximus . arises from the
back of the ilium nearly one half its length ; from Glu^us
the joining of the ilium and sacrum; from all the 0r. l.back
spines and irregularities of the sacrum ; and from the part of the
sacro-sciatic ligament and os coccygis. Its thick JE? the
fleshy fasciculae come in a winding and oblique direc- 2- os sa-
tion down to the thigh-bone ; and, being gathered a^r'o-
into a flat and pretty broad tendon, it is inserted into sciatic ]iga-
the root of the trochanter major, and down three ^"scoc-
inches of the outside of the linea aspera. This is cygis-
one of the largest and most fleshy muscles of the aJer^Tt
body; covers all the other muscles of the hip ; the upper
forms the contour of the hip ; pulls the thigh back- part"
wards, 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 direction, but according to the acci¬
dental position of the pelvis with regard to the thigh¬
bone. A large bursa lies under the broad tendon
of this muscle.
CLXVI. The gluteus medius or minor is ^!®sus
smaller than the former, but like it. It arises from or. anterior
all the outside of the ilium not occupied by the sup.spinous
glutseus major. It, like the other, is a fan-formed s^Tand
muscle ; for its fibres converge from its broad origin of
in all the back of the ilium, to form a short flat ten- Tn.tLh^
don which is inserted into the back, or into the very ter major,
top of the great trochanter. It lies in part under the
gluteus maximus j but its chief part lies before the
394
MUSCLES MOVING THE THIGH-BONE.
Gluteus
mi nimus.
Or. 1. dor¬
sum ilii,
2. the ridge,
and
3. the edge
of the great
notch.
In. fore
part of
trochanter
major.
Gemellus
sup.
Or. spinous'
process of
the ischium.
In. root of
the tro¬
chanter.
Gemellus
inferior.
Or. tuber
ischii.
In. root of
the tro¬
chanter.
Pyriformis.
glutaeus maximus; and as certain portions of the
muscle are before the thigh-bone, there 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.
CLXVII. 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 to the fore part of the trochanter major, be¬
twixt 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 tro¬
chanter, and into the linea aspera; the middle
glutaeus into the back and top of the trochanter ;
and the smallest of the glutaei is implanted into the
roughness on the fore and upper part 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.
CLXVIII. The uppermost, the larger, and
stronger muscle, arises from the spinous process of
the os ischium.
CLXIX. The second or smaller head arises in
like manner from the tuber ischii, upon its ball or
outer end. They are fleshy in their whole length.
They meet, and unite their tendons at the great
trochanter. They are inserted firmly along witli
the tendon of the obturator internus, at the root of
that process.
CLXX. The pyriformis, or pyramidalis, comes
from the hollow of the sacrum, runs in the same
line with the lesser glutaeus, and is inserted with the
muscles moving the thigh-bone.
395
two last named muscles in the root of the great tro¬
chanter.
Its origin is from the hollow of the sacrum, rising or. from 3
from the vertebrae of that bone, by three or four sa°cnr^fthe
small fleshy digits, and from the sacro-sciatic notch j from the os
it runs over the sacro-sciatic ligament betwixt the ^"'cavit
glutaeus minor and the gemellus superior, and its under the
round tendon is inserted betwixt them, somewhat grcattro-
connected with each. *
The pyriformis, gemini, obturator internus, and
quadratus, form what some anatomists have called
musculi quadrigemini : 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 obtu¬
rator.
This muscle, the pyriformis, like the others, rolls
the thigh outwards. Its name is from its shape.
CLXXI. The obturator internus, once named obturator
7 . intern.
marsupialis or bursalis, arises from all the in- 0n an tho
ternal surface of the obturator ligament, and from c,1se f t}ju
all the edges of the thyroid hole, from the ilium, LdTbtura!
ischium, and pubis. Its origin is therefore circular tor %•
and fleshy. It runs along the inside of the os ischium,
turns round that bone betwixt the spinous process
and the tuber. 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 In. root
propriety be named one muscle; all the three, viz.
the two gemini muscles, and the obturator muscle
passing between them, were once accounted 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, gives it the
appearance of a purse, thence named marsupialis
or bursalis.
* This muscle is frequently divided by the great sacro-sciatic
nerve.
396 muscles moving the thigh-bone.
Quadratus CLXXII. The quadratus femoiiis is a tllill flat
ijmons. muscjej passing in a transverse direction betwixt the
tuber ischii and the thigh-bone,
or. tubero- It arises from the lower and flattened surface of
jity of the the tuber ischii by a short tendinous beginning,
ischium. goes a little obliquely upwards and outwards, and
/w.intertro- is inserted into the back of the great trochanter, in
chanterai £}iat roughness which is found just where the tro¬
chanter 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 out¬
wards, 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 in¬
crease of strength to that motion of the thigh in which
most strength is required.
There are but two, or chiefly two points for in¬
sertion ; 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 trochanter major. These now may
be called the abductors of the thigh, to pull it out¬
wards ; but we should conclude from this direction,
that they could not pull the thigh backwards, for
the thigh-bone would turn on its axis and elude their
action.
The psoas magnus, the iliacus internus, the pec-
tinalis, and the triceps, do in the same manner go
round the inner side of the bone: the two first to
be implanted into the trochanter minor, the two
latter into the linea aspera, just below it. These are
justly named adductors of the thigh ; their chief use
MUSCLES MOVING THE THIGH-BONE.
.397
is to draw the thighs together, and this is their corh-
bined effect: when the adductors act by themselves,
they pull the thigh forwards, moving the leg, rolling
the thigh-bone, and turning the toe out in a graceful
step ; which is most peculiarly the effect of the pec-
tinalis 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
geminl, &c. which must act. Were the glutei to act
alone, they would rather turn the thigh upon its
axis outwards than pull it back ; but the triceps, &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 glutsei muscles. When
the glutaei act, they pull the thigh directly back¬
wards, 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 exten¬
sors when it is advanced 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 muscles,
agree with the glutaei muscles in bringing the trunk
forwards 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 consideration of the uses and actions of the
muscles are very necessary to the surgeon. If we
suspect that the lameness we perceive in a patient
is arising from the hip-joint, we make him throw out
the thigh in abduction, because the glutaei are ab¬
ductors, and they press the hip-joint in that opera¬
tion, and give pain, and thus prove the seat ot the
complaint. In the same manner, when there is
disease in the course of the psoas magnus, the patient
stoops, and he cannot extend his thigh, because that
stretches the psoas muscle.
398
MUSCLES MOVING THE LEG.
The muscles moving the leg are the most simple
of all; for the knee is a mere hinge, at least it is so
in all our ordinary motions, so that there is no action
to be performed, but those of mere flexion and ex¬
tension, 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 reckoned a quadriceps extensor cruris.
Indeed the French anatomists arrange them so.
Sabatier calls them the triceps femoris. These
muscles, which all converge to the patella, and are
inserted in it, are rectus femoris, — crur^eus or
femorieus, vastus externus, vastus internus.
And these are all implanted by one tendon; be¬
cause 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 two on the outside
and four on the inside of the thigh ; the tendons of
the outside being implanted into the upper knob of
the fibula, and those in the inside into the rough head
of the tibia, forming the ham-strings, and extending
their tendons or aponeurotic expansions downwards
upon the leg.
inside flexors.
Sartorius,
Semitendinosus.
Gracilis,
Semimembranosus.
outside flexors.
Biceps.
Poplitaeus.
EXTENSORS OF THE LEG.
Rectus
.femoris.
CLXXIII. The rectus femoris, sometimes rec¬
tus cruris, is so named from its direction ; it arises
by two heads. The first or greater head arises from
muscles moving the leg.
399
the lower spinous process of the ilium by a short round 0r-inffer-
tendon ; its second head is in a different and some- of Jhe
what of a curved direction : for it comes from the and
edge of the acetabulum, and from the capsular liga- "f the ael°
ment. These join together, and form a flat tendon tabulum-
of four inches in length, which becomes gradually
fleshy and larger down to its middle, and then again
contracts towards the patella. There is a middle
tendinous line, running the whole length of the
muscle, especially conspicuous on its back part,
and towards that central line all the muscular fibres
converge.
The rectus is united at the sides to the vasti, at In. upper
the back part to the cruraeus ; and its tendon, along pateiif the
with that of the cruraeus, goes to be directly im¬
planted into the rotula or patella.
The rectus cruris is the first of those muscles
which Sabatier calls the triceps femoris ; they may
be more properly named the quadriceps cruris.
This large mass of muscle or flesh enwraps the
whole of the thigh-bone behind as well as before ;
for, first, the crurjsus arises fleshy from all the fore
part of the bone; the vastus externus from the
great trochanter, and all the back part and outer side
of the bone ; and the vastus internus arises, in like
manner, from the lesser trochanter, and all the inner
side of the bone, from the trochanter major all round
to the origin of the cruraeus.
CLXXIV. The cruraeus arises from the fore part Cruraeus.
of the femur, between the two trochanters, and it con- Or-tfofr®
tinues its origin from the fore part of the femur, the Eur.' °
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 fore part; and the
vastus internus comes into it about five inches
below its origin, and it joins it at the inner edge and
fore part. At its lower part it is joined to the tendon
of the rectus, to form but one large tendon, which In. the pa¬
is inserted into the rotula. By Albinus, the plate of
13
400
muscles moving the leg.
Vastus ex-
ternus.
Or. root of
the troch.
major, and
the linea
aspera.
In. the pa¬
tella later¬
ally, and
the fascia of
the knee-
joint.
Vastus in¬
tern us.
Or. I. root
of troch.
minor.
2. linea
aspera.
3. fore part
of the bone.
this muscle is given in union with the two vasti,
which is the best method of describing the muscle,
as it is very seldom to be made out distinct from these
two muscles.
Under the cruraeus are sometimes found two little
muscles, or rather two little slips of this muscle,
which are quite distinct. They arise on the fore
part 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
purpose of pulling it up to prevent its being caught;
and when these two (subcrurvei) are not found as
distinct muscles, some fibres of the cruraeus supply
their place.
CLXXV. The vastus exteiinus is the largest of
these three muscles.
Its origin is, by a pretty thick and strong tendon,
from the lower and fore part of the trochanter major;
and it continues its origin from the root of the tro¬
chanter all down the linea aspera, 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 tendon 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.
CLXXVI. 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 fore part of the trochanter minor,
just under the insertion of the psoas magnus, and
from the fore part of the thigh-bone ; it continues
its origin from the linea aspera the whole way down
to the inner condyle, exactly opposite to the origin
of the vastus externus; they leave merely a channel
muscles moving the leg*
401
betwixt them. The vastus internus, very soon after
its origin, joins itself to the cruraeus, or middle por¬
tion, and accompanies it in all its length; and, at
the distance of two inches from the rotula, it unites
itself with the tendon of the cruraeus at its internal
edge ; and this tendon completes that junction which
unites the four muscles into a quadriceps 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 tendon embraces the rotula, some- /n inside
what in the same circular form with the vastus ex- of the pa-
ternus ; and, like the externus, it sends some fibres fel,a»and
ii i int0 tl,e
across the knee-pan, to be inserted in the outer part fascia.
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 sepa¬
rated, and cannot be neatly distinguished.
The use of these four muscles is evident; to
f extend the leg, and to bend the thigh on the trunk,
t or reciprocally to bend the trunk on the thigh,
i This, or these two motions alternately, is the common
use of these muscles, as in walking ; and they are
i 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 increased by the
rotula, which removes the force from the centre,
and gives the advantage of a pulley, which it really
and truly is : without this pulley, these muscles could
be of no use in certain situations ; for instance, in
the recumbent posture: for then the extending
muscles, being in the same line with their bones,
could have no further power j but the rectus, by the
pulley of the rotula, and by its attachment to the
pelvis, raises the trunk, or at least helps the psoas,
the iliacus, and the muscles of the belly.
vol. i. o r>
402
MUSCLES MOVING THE LEG.
The rotula is again attached to the tibia by a strong-
ligament, to sustain the pulling of these greatmuscles.*
The surgeon would do well to remember the
attachment of the rectus to the pelvis in the case of
fractured patella, and to see the necessity of raising
the body of the patient, to keep the broken parts of
the bone in contact.!
FLEXORS OF THE LEG.
Sartorius. CLXXVII. The SARTORIUS Or TAILOR'S MUSCLE, is
so named from its bending the knees, and drawing
the legs across. It is the longest muscle, and a very
beautiful one ; extends obliquely across the whole
length of the thigh, crossing it like a fillet or garter,
about two inches in breadth.
Or. supant. It arises from the upper spinous process of the os
cess of the i^um> by a tendon about half an inch in length ; its
ilium. thin flat belly extends obliquely across the thigh,
t'uberckof a strap, and is inserted in the same oblique form
the head of into the inner tubercle of the head of the tibia; its
the tibia, aponeurosis spreads widely, going over the whole
joint of the knee, a thin sheet of tendon.
From the oblique position of the muscle, it might
in action change its place; but it is so far embraced
by the fascia lata, and is tied by such adhesions, as
to form something like a peculiar sheath of itself.
* These muscles are in continual action ; for their office is to
resist the bending of the knee, which would happen by this in¬
cumbent 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, walking, &c. Since by ex¬
tending 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 quadriceps, i. e. the rectus cru-
raeus, and vasti, weigh four pounds, while the biceps, &c. 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.
f The action of the muscles and the position of the limb in
fractures of the Femur, are considered in my Observations on
Injuries of the Spine and Thigh-bone.—C. B.
muscles moving the leg.
403
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 perform¬
ing that action, whence it has its name, it does all
these; for first the leg and thigh are rolled, then
the thigh is raised, then the leg is bent to draw
it across. Though a small muscle, yet it is of great
power from its origin, and, in some degree, its
insertion also, being much removed from the centre
of motion.
CLXXVIII. The gracilis, sometimes called rec- Gracilis.
tus internus 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 Or. ramus
from the ramus of the os pubis, and near the sym- publt
physis ; and it passes immediately under the integu¬
ments 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 /M. bew
into the side of the tuberosity, at the top of the thews-to-
tibia.
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
sartorius and the gracilis cannot bend the knee ; they,
on the contrary, keep it steady and firm ; but when
* Gracilis, is from its smallness ; rectus internus, is from
its straight direction.
d d 2
401
MUSCLES MOVING THE LEU.
Semitendi-
nosus.
Or. tuber
ischii.
In. into the
tibia below
the gracilis.
Semimem¬
branosus.
Or. tuber
ischii.
the knee is bent, they come into action; for, in
proportion as the muscles which have made the
flexion are contracted, they are less able to contract
farther, and therefore it is desirable that more
muscles should come into play.
CLXXIX. 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 connection betwixt the two muscles con¬
tinues for three inches down from the tuber ischii;
it then departs from the biceps, goes obliquely
inwards, and is flattened and contracted into a ten¬
don, six inches from the knee, and getting round
the head of the tibia, it comes forward to be inserted
into the tuber, at the head of that bone. At this
place, the tendon grows broad and flat; it is ex¬
panded, 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 implanted 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.
CLXXX. The semimembranosus has its name
from the muscle, which is flat, thick, and fleshy,
beginning and ending with a flattened tendon, some¬
what like a membrane, but infinitely thicker and
massier than such name should imply.
It arises from the tuber ischii, before the semi¬
tendinosus 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
muscles moving the leg.
405
tendon, which, gliding behind the head of the tibia, In. head of
is inserted there. * the tibia'
This muscle has little connection with any other.
It lies under, or, more particularly speaking, on
the inside of the semitendinosus, and the two to¬
gether form the inner hamstrings. The hamstring
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 con¬
sequently 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.
CLXXXI. The musculus poplit^us, which popiuams.
is so named from its lying in the ham, is a small tri¬
angular muscle, lying across the back part of the
knee-joint, very deep under the hamstrings, and
under the muscles of the leg.
Its origin is from the outer condyle of the thigh- ^cMe
bone, and from the back part of the capsule of the c°n y e
joint; its tendon is short and thick, but of no great
extent. It passes fleshy behind the knee-joint; and /n.triangu-
it is inserted broad into a ridge on the back part of ^ the ba^
the tibia; so that by its small origin and broad in- ofthetibL
sertion, it is a fan-like muscle, its upper fibres being
almost transverse, and its lower fibres nearly perpen¬
dicular. Besides bending the leg, it is useful by
pulling aside the capsule to prevent its being caught.
CLXXXII. The biceps flexor cruris, so named
from having two heads, a long and short one, lies im¬
mediately under the skin, in the back part of the leg,
* 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 betwixt them must be very
oblique; for the membranous tendon descends low upon the
back part or edge, and the tendon of insertion begins high upor
the fore edge of the muscle.
1) D 3
406
muscles moving the leg.
running down from the pelvis to the knee, to form
the outer hamstring.
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 some¬
what connected with the origin of the vastus externus
muscle, and the insertion of the glutagus maximus.
The tendons of the two heads are joined a little above
the fibuL°f ^ie 0U^er condyle, and go outwards to be inserted
into the outer part of the head of the fibula forming
the outer hamstring.
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 im¬
planted 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.
Fascia. We must not relieve our attention from
these posterior muscles of the thigh without consider¬
ing the manner in which the great fascia comes down
on the back part of the thigh to cover them, and to
form the popliteal cavity. The fascia, strengthened
as it were by its connection with the linea aspera,
stretches down over the hamstring muscles and their
tendons, embraces them, and holds them together;
and betwixt the flat part of the femur, the ham¬
string tendons laterally, and the fascia behind, there
is a cavity, (if we may call that a cavity which
Or. tuber
ischii.
2- linea
aspera.
muscles moving the leg.
407
is filled with loose cellular membrane and fat,) which
transmits the popliteal artery and vein and nerve.
I his cavity is particularly important to the surgeon,
because the artery here is subject to disease or rup¬
ture ; and then the popliteal aneurism is formed.
The muscles of the foot are six extensors and two
flexor muscles.
EXTENSORS.
Gastrocnemius vel gemellus, ( lying on
Plantaris, J the back
Gastrocnemius internus, vel soleus, j part of
Tibialis Posticus, , (, the leg.
peronieus longus, f on the outside
•{
b re vis, J of the leg.
FLEXORS.
The tibialis anticus, C lying on the fore part
The peronieus tertius, \ of the leg.
CLXXXIII. The gastrocnemius is often divided Gastrocne-
into two muscles, named gastrocnemii or gemelli. mius"
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 j and he calls it
the extensor suralis.
The gastrocnemius is the great muscle of the
calf of the leg ; its two heads are two very large and femur.
fleshy bellies, which arise from the tubercles of the
thigh-bone. The inner head is the larger, and arises /w oscalcis-
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.
The outer head is shorter than this: it arises in
the same way, from the outer tubercle of the thigh¬
bone ; and the two muscles meet and run down
together, forming the appearance of a rapha, by the
direction of their fibres ; but the two bellies continue
d d 4
408
MUSCLES MOVING THE LEG.
distinct till they meet in the middle of the leg. They
are distinct at their back part, but at their fore part
they are connected by a tendinous aponeurosis, or
strong but flat tendon ; and the two bellies being,
about the middle of the leg, united firmly, they form
a large flat tendon, very broad at its beginning, which
unites with that of the soleus a little above the ancle.
Soieus. CLXXXIV. Soleus. — This name is from its
resemblance to the sole fish; and it is often named
gastrocnemius intern us. This, like the last muscle,
has two heads, which arise from either bone.
Or. head of One head arises from the head of the fibula, and
Ind^ack' continues to adhere to one third of the upper part
part of the of the bone ; another head arises from about three
ubia. inches of the part of the tibia, immediately below the
insertion of the poplitaeus. The first of these heads
is large and round ; the second is smaller and flat:
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 approaches the heel. A little
below the middle of the leg, this tendon is united
with the tendon of the gastrocnemius, to form the
great back tendon named tendo Achillis ; and some¬
times, though very rarely, chorda magna.
The tendon is large ; it grows smaller as it ap¬
proaches the heel; when it touches the extremity
in. os cai- 0f the heel-bone, it expands to take a firmer hold.
In running, walking, leaping, &c. this muscle, with
the extensors of the leg, are the principal agents.
The external 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 j
but the gastrocnemius internus is a mere extensor of
the foot; and both together have such strength as
often to break the tendo Achillis.
piantaris. CLXXXV. Plantaris.—This muscle is named
from a mistaken notion of its going to the planta
pedis, or sole of the foot, to form the plantar apo¬
neurosis, like the palmaris of the hand; but, in fact,
MUSCLES MOVING THE LEG.
409
it does not go to the sole, but is a mere extensor of
the foot, inserted along with the tendo Achillis.
This long and slender muscle is situated under
the gastrocnemius externus. It arises from the ex- Or. extern,
ternal condyle of the femur wholly fleshy ; it also condyle-
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 soleus ; and when the tendo Achillis begins,
the tendon of the plantaris attaches itself to the
inner edge and fore part of the Achillis tendon ; it
accompanies it down to the heel, running in a groove
which seems made to receive it; and it is implanted, In. inside of
with the tendo Achillis, into the inner side of the theoscalcis
heel-bone. It is often wanting.
The use of this muscle is to tuck up the capsule,
in the great bendings of the knee-joint, and to assist
the gastrocnemii muscles.
The PERONJsi muscles are those which arise from
the fibula. They are named from their length being
different; the peron^eus longus being as long again
as the brevis, for it is one half longer in its origin,
the one rising at the head, the other at the middle
of the bone; and again, it is one half longer at its
insertion, going fully round under the foot to the
opposite side, while the shorter peronseus stops at
the side of the foot to be inserted.
CLXXXVI. The peron^eus longus is so named Peron®"»
from its lying along the fibula. It arises partly ^rT^e^
tendinous, chiefly fleshy, from the upper knob of the and almost
fibula, and from the ridge of the bone down to within ^head
three inches of the ancle. It has another small slip of the tibia,
of a head from the upper part of the tibia, above
where the fibula joins ; it has also adhesions to the
tendinous partition, which separates this from the
EXTENSOR DIGITORUM COMMUNIS and the SOLEUS.
Its tendon begins very high above the middle of
the leg, and it continues to receive the fleshy fibres,
almost at right angles in the penniform manner.
The tendon is concealed down to about or below
410
muscles moving the leg.
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 ancle, and which
gives shape to that part.
In passing the outer ancle it runs down through
a cartilaginous pulley, or annular ligament, which
also transmits the peronaeus 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 ob¬
liquely across the arch of the foot, goes quite down to
fo meTif" °PP0S^e side, and is inserted into the metatarsal
tern.Vnd bone of the great toe, and the great cuneiform bone
tarsal bone 011 ^ founded. Under the eminence of the
of the great os cuboides, it suffers great friction, so as to be
toe- 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 ancle ; 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 obliquity to the foot, which is so handsome and
natural, and useful in walking. This muscle parti¬
cularly turns down to the ground the inner edge
of the foot; so it presses to the ground 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 particularly in
dancing.
Peronaeus CLXXXVII. The PERONJEUS BREVIS is like its
brevis. •
or. ndge of fellow, except in length and insertion. Its origin is
the fibula, from the ridge of the fibula, beginning about one
iTsToJer"1 third down the bone, and continuing its adhesion the
half. whole way to the ancle. It also lias adhesions to
the tendinous partition which is betwixt it and the
common extensor ; so that these two muscles are,
by such adhesions, very difficult to dissect. It is
smaller at its origin, but increases in its fleshy belly
MUSCLES MOVING THE LEG-
411
as it descends ; and it is fleshy lower down than the
peronaeus longus. It is, like it, a penniform muscle.
The tendons of the two peronaei pass together, by
the outer ancle, in the same ring; but the tendons
cross each other ; for the peronaeus longus is in its
belly more forward. The brevis lies under and
behind it, quite covered by it, and yet the tendon
of the _brevis, by creeping under the longus, gets
before it, just under the outer ancle : and from that
it runs in a separate groove, superficially upon the
outer edge of the foot, to be inserted into the meta- In- meta-
tarsal bone of the little toe. In both muscles the of the little
tendon is upon the outer edge, and begins almost as toe' ^n(?,the
high as the upper head of each muscle. This tendon oscubo1 cs'
of the peronaeus 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 somewhat 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 coincides 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.
CLXXXVIII. The PERONiEUS tertius is a third Peron*us
muscle, having its origin from the fibula ; but as its tertu,s'
tendon passes before the malleolus externus, and as
it is inserted into the outside of the foot, it has a
contrary action to the peronaeus longus and peronaeus
brevis. The peronaeus tertius lies on the fore part 0r lower
of the fibula, and rises from the middle of that bone, half of the
and down to near its lower head. Its tendon does fibula'
not pass into the same sheath with the peronaeus
longus and brevis, but goes under the annular liga¬
ment on the fore part of the ancle-joint, to be inserted
into the root of the metatarsal bone, which sustains the little
the little toe. It is so much connected with the toe-
extensor communis digitorum, that there is often
great difficulty in dividing the two. The action of
412
muscles moving the leg.
Tibialis
posticus.
Or. 1. back
of the tibia,
2. and fi¬
bula,
3. fore part
of the tibia,
and 4. in¬
terosseous
ligament.
In. almost
all the
bones of the
tarsus.
1. os calcis,
2. cuboides,
3. cunei-
forme med.
internum,
4. metatar¬
sal of the
middle toe.
Tibialis
anticus.
this muscle balances the connection of the tibialis
anticus, and the two together bend the foot, that is,
bring it to an angle with the leg.
CLXXXIX. The tibialis posticus is a penni-
form muscle ; its tendon goes round the cartilaginous
pulley of the inner ancle.
It is named tibialis from its origin, and posticus
from its place.
It arises from the back part and ridge of the tibia,
from the opposite part of the fibula, and from the
interosseous membrane below these. Some fibres
pass between the bones at the upper part, and take
an origin from the fore part of the tibia; and it
continues its attachment to the interosseous liga¬
ment, quite down to the ancle. It has also strong
attachments to the surrounding 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 continues to receive flesh quite down to the
ancle. It passes in the groove of the inner ancle,
and is retained there by such a ligament as holds
the peronasi. After passing the ligament, it expands
in the hand-like form, to grasp the bones of the
tarsus ; and it is expanded much more than the
peronaeus, for it sends roots down among the bones
both of the tarsus and metatarsus, so as to take hold
first on the lower rough part of the naviculare in
passing over it. Then it is implanted into the middle
metatarsal bone, then into the calcaneum, into the
os cuboides cuneiforme internum and medium ; and
where it passes over the os naviculare, it is hardened
into a sort of sesamoid bone. In short, it is implanted
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 peronasi, it directly extends the foot.
CXC. The tibialis anticus crosses obliquely
the fore part of the leg. It arises from the fore
1
muscles moving the toes. 413
part and outside of the tibia, part of the fibula, o 1. head
and interosseous ligament. It begins just under the panofthe
outer tuber, and continues its adhesion down two tibi.a>
thirds of the bone ; then the tendon begins to be seousteiigS~
formed : and this muscle, like almost all the smaller 3-head of
ones of the leg, adheres to the tendinous partitions, the fibula"
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 appearing
till within four inches or so of the ancle, when it
begins to pass obliquely over the leg, and having
completed the crossing above the ancle, it goes under
the annular ligament in a peculiar ring, runs along
the side of the foot, and is implanted into the os /n. cunei-
cuneiforme internum, and a small production of the formein^r-
tendon goes forwards to be inserted into the meta- nXtarsai
tarsal bone of the great toe. bone of the
This muscle turns the great toe towards the leg, grcat toe"
and when assisted by the peronaeus tertius directly
bends the foot.
muscles of the toes.
The long muscles of the toes are just four, two
flexors, and two extensor muscles. The flexor
muscles lie upon the tibialis posticus, or behind,
betwixt it and the soleus. 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 posticus, over the pulley of the inner ancle
into the hollow of the foot. The tendons of the
extensor muscles keep with that of the tibialis an¬
ticus, and cross over the fore part, or prominence of
the ancle, where the tibia is united with the astra¬
galus. And in dissection ;we must follow these in
an opposite order to that in which they are described,
for next to the fore part of the soleus is, 1st, the
flexor pollicis ; 2dly, the flexor digitorum ; and
3dly, the tibialis posticus.
iU
MUSCLES MOVING THE TOES.
Flexor Ion- CXCI. The FLEXOR LONGUS POLLICIS is Small
and pointed at its origin, and arises fleshy from
fourths of three fourths of the fibula, to within an inch of the
the fibula, outer ancle and interosseous ligament. It grows
mteross. lg. anc[ larger as it descends, and adheres to the
tendinous partitions of the tibialis posticus, and of
the peronaei. Its tendon can be seen only about an
inch above the joint of the ancle. It passes down
behind the inner ancle, 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
in. last root of the great toe ; it then goes forward in a
the*great° sheath, to be inserted into the last bone of the great
toe- toe, at which implantation it is enlarged. Sometimes
it sends a small tendinous insertion into the os calcis.
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; and, therefore, we
should not be rash in cutting away the great toe,
for in it consists not the strength of the foot only,
but of the leg.
Flexor Ion- CXCII. The FLEXOR LONGUS DIGITORUM PEDIS
?umdlglt0~ 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.
Or. i. back It arises from the back and inner part of the
tiWa,°f the tibia, its whole length, that is, from the end of the
2. septum, poplitgeal muscle, and from the septum tendinosum,
by which it is divided from the tibialis posticus,
which lies immediately before it; and it continues
this origin from the tibia down to within three inches
or so of the ancle. About the middle of the muscle
4
muscles moving the toes.
415
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 ancle,
(within two inches of it,) and the flesh still accom¬
panies it quite down to the joint. It crosses the
tendon of the tibialis posticus behind the ancle-joint,
and goes forward in the groove of the os calcis, tied
down by a sort of capsule, or annular ligament. In
the arch of the foot, it crosses the tendon of the
flexor pollicis, from which it receives a slip of
tendon ; and thus the office of either is assisted by
the other, and could be wholly supplied by it: it
then passes over to the middle of the sole, and
growing flatter and thicker, divides into four flat
tendons. These go forward, diverging till they
arrive at the ends of their metatarsal 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 the base
into the root of the third or last bone of each toe. phakn^of1
These tendons, like the corresponding ones of the four toes,
hand, seem to be slit 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 pecu¬
liarly the last bone; and also to extend the foot,
keeping the point of the toes to the ground, conse¬
quently assisting the gastrocnemii, and all the mus¬
cles used in walking, &c.
CXCIII. The massa carnea JaCOBI SyLVII, Ol' Flexor ac-
n t • ,i i cessorius.
plants pedis, flexor accessonus, lies m the sole
of the foot; it is a small body of flesh, naturally
connected with the flexor longus. The massa car-
Or. sinuo-
nea arises from the lower part of the heel-bone, in
two divisions, one (the external one) tendinous, the
4-16
muscles moving the toes.
other fleshy. It is, upon the whole, pretty nearly of
in. tendon a square form ; it joins the tendon of the flexor
hLgus^07 longus, before its division into tendons for each toe,
and by the advantage with which it acts in con¬
sequence 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 considered as a distinct muscle, and by
others, as the origin and first beginning of the lum-
bricales pedis.
Thus Cowper considers the massa carnea, and the
lumbricales, as one and the same : that the massa
carnea joins the tendon, covers it with its flesh, con¬
tinues fleshy along the common tendon, till at the
bifurcation it also parts, along with the four tendons,
into four small fleshy muscles, which are called lum¬
bricales.
Albinus, again, paints the massa carnea, distinctly,
terminating at the common tendon, and the lumbri¬
cales as arising distinct from each of the divided
tendons.
CXCIV. The flexor brevis digitorum is also
rum. gl ° named the flexor sublimis or perforatus. It arises
Or. lower from the lower part of the heel-bone, or the bump
part of the i.i it * i i
os calcis, upon which we stand. It arises by very snort ten-
and th<? dinous fibres, and, being placed immediately under
plantar apo- - . ° . r , i i l p •, l i
neurosis. the plantar aponeurosis, it takes hold or it, and aiso
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 tendons 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
muscles moving the toes.
417
perforated tendon fixes itself by the two forks to In. the se-
each side of the second bone, or phalanx of the offom°toZ.
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 correspond¬
ing obliquity of the short flexor; for the tendon of
the long flexor coming round the 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.
CXCV. The lumbricales must be dissected after lumbri-
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 ten- °fftltenfldo"
dons. They, like them, pass through the digitations iongus.eX°r
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 ^e' ^set of
with the tendons of the extensors. Their insertion phalanges,
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 implanted into the tendon of
the long flexor. The lumbricales again rise from
the tendons of the long flexor, beginning just where
the massa carnea ends in it; and the lumbricales
are the flexores primi internodii; the short flexor
muscle, the flexor secundi internodii; the long
flexor, the flexor tertii internodii digitorum.
vol. i.
418
MUSCLES MOVING THE TOES.
EXTENSORS OF THE TOES.
Extensor CXCVI. The EXTENSOR LONGUS DIGITORUM PEDIS
longusdigi • difficult to dissect, from its numerous ad-
torum. . . J '
hesions.
Or. i. upper It arises properly from the head of the tibia, at its
part of the outer and fore part, just under the knee ; but it has
head of the a}so strong adhesions to the inner surface of the fascia,
tibia. • • .
2 almost tendinous partitions betwixt it, and the tibialis
the whole anticus before and betwixt it, and the peroneei behind,
theSfibuk and also to the interosseous ligament, and to the
3 interos- edge of the fibula. Its small origin soon becomes
seous liga- thick, and is divided even from the beginning very
ment' . perceptibly into three distinct portions. These soon
ie ascia. £*orm f.}iree round tendons, which go obliquely inwards,
pass under the annular ligament of the ancle, and
run in a ring of it, peculiar to them and the peronaeus
tertius. They then traverse the two bands of the
annular ligament, upon the fore part 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 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
in. base of toe, and the third serves the fourth toe. Here the
phalanx of tendon of the long extensor receives four other
four toes, tendons ; first, of the interossei externi; secondly, of
over "the the interossei interni; thirdly, of the long flexor;
toes. fourthly, of the lumbricales ; and these form a very
large sheath, quite surrounding the toe.
Extensor CXCVII. The EXTENSOR DIGITORUM BREVIS is SO
breves!um connected with the extensor longus, 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.
Or. i. outer Its origin is from the outer side, and fore part of
aartofu the heel-bone, and also from part of the annular liga-
os'caicis.1 ment. It is smaller where it arises by a short tendon
MUSCLES MOVING THE TOES.
419
from the heel-bone, but it gradually increases in 2'■ ann"'ar
size : it divides early into four heads, which are mus- llgamuit
cular, and very distinct; the two inner of which are
larger, the two outer more slender : each head has
already formed an oblique tendon under its flesh,
which begins to appear naked about half way down
the metatarsal bones. These tendons cross those of
the long extensor, and pass under them nearly about
the end of the metatarsal bones. Then one is im-
planted into the first bone of the great toe, on the Sceptre
inside of the long tendon under which it had turned. little toe-
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.
CXCVIII. The EXTENSOR POLLICIS PROPRIUS is a Extensor
very slender muscle, running from the top of the leg po11icis-
to the second joint of the great toe. It arises from Or. from
the fibula, a little below its head, takes fibres from JJ^JJofthe
the interosseous ligament, grows tendinous as it spine of the
approaches the foot, then, passing under the annular l^ero'ss.iig.
ligament, and the cross ligament of the foot, it In. last
o-oes onwards to the second joint of the toe over phalanx of
o the great
the first. toe.
The succession in which these muscles lie, under
and behind each other, is this : first, the tibialis anti-
cus, the outermost muscle, arises from the fore part
of the tibia, nearest the fore part 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 peronaeus tertius lies behind
the common extensor, like a part of that muscle.
E E 2
420
muscles moving the toes.
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 strengthened at
the knee, where it adheres to each point of bone ; it
descends very thick and strong over the leg, binding
down and strengthening the tibialis anticus and ex
tensor muscles. The sheath grows thinner towards
the ancle, but where it passes over the joint it is so
remarkably strengthened by its adhesions to the outer
and inner ancles, that it seems to form two distinct
cross bands, which, going from the point of the outer
ancle, across the extensor tendons, to the point of the
inner ancle, forms a strong crucial ligament, resemb¬
ling the annular ligament of the wrist; so that this,
which is called the crucial ligament of the ancle or
foot, is plainly but a strengthening of the common
sheath.
The remaining muscles in the foot are the inter-
ossei, which, in the foot, are found single on the
lower surface or sole, but double, and two-headed,
upon the upper part of the foot. The abductor,
flexor, and adductor pollicis, which surround the
great toe, something like those of the thumb ; and
the abductor and flexor minimi digiti, surrounding
the little toe ; and there is a small slip of muscle,
the transversalis pedis, which goes across the sole
of the foot.
Abductor CXCIX. The abductor pollicis arises, by very
poihcis. short tendinous fibres, from the knob of the os calcis,
ds'andTig. and also from a ligament which stretches from this
of the navi- knob to the sheath which belongs to the tibialis pos¬
ticus ; and it arises also from the tendinous partition
betwixt it and the short flexor of the toes; and
although it forms a tendon beginning opposite to the
cuneiform bone, the tendon is not naked, till it has
reached the middle of the long metatarsal bone. It
unites with the short flexor of the same toe, and is
lstp'haian'x! inserted into the first bone or phalanx of the toe at its
root, and os sesamoideum. Its use is to pull aside the
toe, and at the same time to bend it a little ; it also
13
culare.
In. sesa¬
moideum
muscles moving the toes.
421
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.
CC. Flexor brevis pollicis. This muscle is Flexor bre-
much shorter than the last, and lies betwixt the vlspolllcis-
abductor and the adductor ; it lies immediately
upon the metatarsal bone.
Its origin is by a pretty long tendon from the heel- Or. os calcis
bone, and from the os cuneiforme externum, by ®ndcunei-
T iiTi i f* ii f°rrae ex~
two separate slips from the heel-bone, being a full tern,
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 In. ossa
phalanx. These tendons contain the sesamoid bones; sesamo1 a*
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.
CCI. The adductor pollicis is the third and adductor
last portion of the muscle which encircles the great polllcls-
toe.
It arises from the heel-bone by a tendon as long Or.oscai-
almost as that which it gives the abductor : it does ^ and°cu-
not immediately arise from the heel-bone : but there neiforme
is a ligament extended from the heel-bone to the os externum-
cuboides, and it arises from that ligament: this is
the ligament under which the tendon of the pero-
naeus 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 externum,
sesamoid bone, or directly into the first bone of the
great toe.
CCII. The TRAfrsvERSALis pedis extends trans- trans¬
versely 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 fore part of the metatarsal bone Or. meta-
of the great toe, and the sesamoideum internum, and 2*^
EE 3
422
muscles moving the toes.
moideum of inserted into the under and outer part of the ante-
the great r-or extremity of the metatarsal bone of the little toe
and ligament of the next toe.
jn.meta- Its use is said to be, to make a sort of gutter in
tarsal bone^ t]ie foot, by drawing the heads of the metatarsal bones
toe, and ° together ; but is it not evident that this is one of
tigatersus°f many instances of muscles being a more perfect
support than ligaments ? — It is a support, having a
sort of intelligence, contracting or relaxing, accord¬
ing 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.
Abductor CCIII. The abductor minimi digiti, like the
mm. dig. abductor pollicis, is a pretty long muscle, but very
slender, lying on the outer side of the foot.
Or. os eaicis Its origin is from the knob of the heel-bone, and
and hg. from the tendinous septum, which covers the flexor
brevis : it forms two small tendons in the same direc¬
tion : one small and shorter tendon is fixed in the
metatarsal bone, at its root: the other goes forward
in. root of to be inserted into the root of the first bone of the
bone oft the *:oe' so muscle dearly performs both the
little toe.1 offices ascribed to the other flexors. It bends the toe
to which it belongs, and it extends and supports the
tarsus in walking ; and it carries the toe a little out¬
wards, from which it has its name.
Flexor bre- CCIV. The flexor brevis minimi digiti is next,
vis mm. an(j -s a]most same muscle in place and office: it
Or.l.meta- an exceedingly small muscle ; it just measures the
tarsal bone length of the metatarsal bone, and arises from it. Its
ofthehuie orjgjn js from r00£ Qf t]ie metatarsal bone of the
2. os cuboi- little toe, and from the ligament by which that bone
des- is connected with the os cuboides ; its small belly
in. root of runs the length of that bone, and it is implanted by a
the first short tendon, into the root of the first bone of the
bone of the ,. t
little toe. little toe.
Its use is to bend the toe.
intend!*1 CCV. The interossei interni are three small
same as in m]uscles seated in the planta pedis, as the interossei
the hand, manus are in the palm of the hand. Their slender
muscles moving the toes.
423
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.
CCVI. The interossei externi are, like the cor- g^nf561
responding muscle of the hand, four in number, and same as in
double headed, and have been named bicipites. They the hand-
rise from the metatarsal 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 tendons 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.
The office of these muscles is to extend the toes.
Fascia of the leg. — The dissection of these
muscles on the fore part of the leg and foot is some¬
what difficult from the relations of the fascia. This
fascia is a continuation of that of the thigh, for we
trace that membrane over the knee-joint, as I have
said, into the tibia. But from the spine of the tibia
it takes a new origin, and, as it were, renews its
strength. It not only covers the tibialis anticus and
extensor muscles, but sends strong septa betwixt
them. Its obvious use at this point is to give attach¬
ment to the muscles, and to afford that origin which
the bone cannot do but through its intervention.
Here, during the dissection, it will be seen, that the
fascia is very erroneously described as a covering
to the limb, since it dives betwixt the muscles, and
gives off connections to the bones and deeper mem¬
branes. While a superficial fascia covers the gastroc¬
nemius and the tendo Achillis on the back of the
leg, another layer slips under these, and, having con¬
nection with the bones, covers the tibialis posticus
and flexors.
e e 4
424
muscles moving the toes.
Towards the ancle on the fore part, the fascia is
strengthened by strong tendinous fibres, so as to
form the annular ligament at this point; and from this
it is stretched over the dorsum of the foot to 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 apo¬
neurosis. In the foot, such an origin is still less
probable ; for the plantaris tendon 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 divided into three sheaths.
Sabbatier makes a middle, external, and internal
portion of the same aponeurosis. Albinus also de¬
scribes it as three distinct aponeuroses ; 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 tendon arises from the very point
of the knob. The inner fascia arises from the inside
of this ; and the outer one from the outside. And
though thus divided into three heads, yet the whole
origin is from the heel-bone. From this point the
aponeurosis goes forward expanding till it is as broad
as the roots of the toes ; so that the whole has the
shape of a sandal; and as it expands, its fibres are
scattered, so as to have a radiated appearance.
Accordingly, the part nearest the heel is thicker,
while the broader part is thinner.
of the muscular power.
4 <25
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 into 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
aponeuroses ; for by these perpendicular partitions,
the hollow of the foot is separated into three dis¬
tinct chambers : under the middle one are concealed
the tendons of the long flexors, with the lumbricales
and short flexor muscles : under the outer one the
flexor and abductor of the little toe : and under the
inner one the abductor, 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 sup¬
ports the arch of the foot, both in standing and in
motion, passing from heel to toe like a bow-string
across its arch : that it binds down the muscles, and
consequently supports and assists them in their
strong actions : that it gives origin, or part of their
origin, to many of the muscles ; 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 muscle pass.
OF THE MUSCULxlR POWER.
That contractile power which resides in the mus¬
cular or living fibre, is a phenomenon the most
wonderful and perplexing of all. When we cannot
reach the true point, the mind too often conde¬
scends to the most trifling pursuits; and so, when
the older physiologists could not understand the
OF THE MUSCULAR POWEK.
intrinsic nature of this muscular power, they endea¬
voured 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 grada¬
tions of animals of different species or different sizes,
the colours 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 acci¬
dental property which it so often wants, and of which
it may be so easily deprived, while we may define it
more truly by its contractile power, the only evi¬
dence 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 subject; but even such discrepan¬
cies are trivial to those which, in one of the greatest
of these minute philosophers, are found almost in the
same page ; sometimes affirming the ultimate fibre
to be greater or smaller, according to the strength of
the subject, and again making them of equal size in
the whale and in the insect.
Others, less troubled about the size of these ulti¬
mate 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 con¬
ceptions of their authors, were finally proved by the
OF THE MUSCULAR POWER.
microscope, forsooth ; and while one author was
drawing his rhomboidal fibres, all conjoined in regu¬
lar succession ; and another describing them also
from the microscope, as consisting of six cylindrical
fibres, involved in a spiral one, a third was reckon¬
ing the fibres as a succession of spherical bodies :
and Cowper thought that he was injecting with quick¬
silver chains of bells jointed with each other. For
the honour of the age, these vanitiesare forgotten now.
Physiologists have, by a late sense of their own
weakness, been at last humbled to this becoming,
but unwilling acknowledgment, that this contrac¬
tility 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
organization is destroyed this power is lost. We
have resigned the search after a mechanical or phy¬
sical 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 these feelings or mo¬
tions which result from the nerves. The vis insita
is that power which belongs to muscles, and is the
source of motion. The vis nervea is that property
which is peculiar to nerves, and is the cause of
voluntary motion. They convey the will to the mus¬
cles, but are incapable of motion.
This irritable power residing in muscles may be
defined to be the property by which muscles feel and
re-act, upon certain stimuli being applied; and that,
while certain orders of muscles are obedient to their
own stimuli only, as the heart to the blood, the bladder
to the urine, other orders of the muscles are ready to
receive the commands of the will. Phis power, in¬
herent in the muscular fibre, belonging to its con¬
stitution, and not derived from without, is the vis
insita, or irritability of Haller*, the vis vitalis of
Goerter, the oscillation of Boerhaave, and the tonic
* The irritability of a muscle is, perhaps, more properly the
vis insita, or inherent power, called into immediate action by the
428
OF THE MUSCULAR POWER.
power of Stahl. It is seen in the spontaneous and
tremulous contractions of muscles when lacerated,
as in wounds, when cut in operations, when entirely
separated from the body; as in experiments upon
animals, like that tremulous motion which we often
feel in various parts of the body, 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 muscles will contract, and it will be
fixed in that posture till the organization yields and
begins to be dissolved ; it is the same inherent power
by which a cut muscle contracts and leaves a gap.
This is but a faint indication of that latent power,
which can be easily excited to the most violent
motions, and on which all the strength of the muscles
depends: for the ligaments, tendons, bursas of
joints, and all those parts which have no such power,
are capable of bearing the same weight when dead
as when alive. But such is the dependance of the
muscle on this vital endowment, that the moment it
dies its power is gone ; and the muscle which could
lift a hundred pounds while alive, cannot bear the
weight of a few pounds when dead. This latent power
may be brought into full action by various stimuli.
The latent power itself is called vis insita; the acting
power put into action, or the proof of the vis insita,
upon applying stimuli, is called the irritability of
muscles.
Authors have doubly confounded the power of the
muscles and the nervous system, by observing that
the muscle continues to act when separated from the
brain by the division of its nerves. It would be easy
to shew that there can be no such separation of
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, elasticity, and of muscular power combined.
OF THE MUSCULAR POWER.
429
the muscular and nervous systems, and that when
the muscle is even cut out, and exhibits contractions,
these phenomena do not belong to the muscle, ex¬
clusively of the nerves. Anatomy teaches us that the
nerves meet every where with the muscular fibre, and
to separate them is impossible. Have we not learned
that every fibre of muscle has its sheath, and that it
lies insulated from every other fibre : what then is the
influence which combines a million of fibres in one
simultaneous action ? If a muscle so cut out be
pricked, and acts, does it not imply that every fibre
sympathizes ; and what other bond can unite them
but the nerves?
Upon stimulating any muscle by touching it with
a caustic, or irritating with a sharp point, or driving
the electric spark through it, or exciting with the
metallic conductors, as of silver and zinc, the muscle
instantly contracts; although the nerve be cut so as
to separate the muscle entirely from all connection
with the system, although the muscle itself be
separated 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 long after; the heart separated from the
body contracts when irritated ; the bowels when torn
from the body continue their peristaltic motion, so as
to roll upon the table, ceasing to answer to stimuli
only when they become stiff and cold. 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 although they feel the
stimuli by which these contractions are produced,
they do not convey that feeling to the brain. The
muscular parts have all the irritability of the system ;
while nerves have all the sensibility of the system,
and have the power of exciting motion without the
power of motion.
430
OF THE MUSCULAR POWER.
The vis insita is a power that is in continual
force, preserving the parts ready for their proper
stimuli, whatever these may be; one set obeying their
own peculiar stimuli, while others are obedient to the
influence of the will. The heart is stimulated by the
quantity of its blood ; the stomach by the presence of
food ; the intestines by their contents : the urine sti¬
mulates 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
voluntary nerves, and so are obedient to the will; for,
to our limited view, the nerves seem to be the sole
messengers of these commands, and any stimulus to
the nerves moves the muscles like the commands of
the will. The absence of the due stimulus to each,
or the presence of the ordinary stimuli in too great
power, will excite irregular motions, as fulness of
blood in the heart, poisons in the stomach, acrimo¬
nies 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 in¬
fluence of the will; for these are the machines of the
system, whose motions could not stop, must not be
interrupted, nor lowered, nor raised, but must move
and act according to the needs of the system. Not
left to the irregularities or carelessness of voluntary
motions, they are governed each by its own peculiar
stimulus, and act in a continued and equal course.
Thus, there are in the body two living powers,
which are as cause and effect in all the motions ot
our system. The nerves stand as an intermedium
betwixt all external objects and our general sense;
4
OF THE MUSCULAR POWER.
431
by the impressions through these come pleasure
and pain, and all the motives to action ; by the will,
returned through other nerves, all voluntary motions
ensue. Thus are the nerves, as internuncii, betwixt
the external impression 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 property, the sub¬
ject of its operation, remains the same. Some have,
with reason, supposed that 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 perfect or low; but the energy of the muscle,
which is to answer to this power, remains ever the
same, while its organization remains: the nervous
power is exhausted and languid ; but the muscular
power is always perfect, always ready for the excite¬
ment of stimuli, or for the commands of the will.
The irritability, or inherent power, not only keeps
the muscles 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. The muscles of one side balance
the opposite muscles ; and if the muscles of one side
be relaxed by palsy, the action of the opposite mus¬
cles 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.
432
OF THE MUSCULAR POWER.
We naturally revert in this place to the sound
opinions of Mr. Hunter, who, speaking of life, dis¬
tinguishes the properties or actions of parts into two,
those which regard their own preservation, and those
which regard the general economy. These latter
may be interrupted as by suffocation ; but if the
powers of the separate parts remain, we may produce
resuscitation and reanimation, by restoring the cor¬
responding sympathies. It is the remains of con¬
tractile 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 mo¬
ment this lingering portion of life is gone, the body
dissolves, and falls down ; and so we judge of fresh¬
ness, by the rigidity of the flesh, and foresee ap¬
proaching putrefaction, by its becoming soft. 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 ex¬
plodes (if we may be allowed the expression) all the
powers of life; in these the contractile power is
effectually destroyed or lost by the entire death.
The life stopped all chemical decomposition, but
now putrefaction comes quickly on. In those who
die of the plague, of poison, of fevers, or of any
sudden and violent disease, which at once extin¬
guishes life in the vulgar sense, and robs the system
of that remnant of life, which the physiologist could
produce to view; in all these cases, the body
becomes putrid in a few hours.
And here we are led to observe a fact of great
consequence to the Pathologist; the muscles are
not equally under the influence of the sensorium ;
some are prompt and exact, under the guidance of
the will, whilst over others we have no command at
all; and there are not a few which we command
indirectly, that is, we put a certain class of muscles
into operation, which are followed by the combination
of others, over which we have no direct power.
And as the muscular system is thus connected with
OF THE MUSCULAR POWER.
the sensorium in different degrees, so we might be
led to expect that these muscles might be differently
influenced when the mind is oppressed. In fact, in
pioportion as the muscles are more or less imme¬
diately under the guidance of the will, so they are
affected when the brain is oppressed. This we may
see in the approach of natural sleep, or in the effects
of intoxication. The influence steals over the eyes,
the countenance, and the limbs, until the vital ope¬
rations of respiration and circulation are all that
remain.
But, before dismissing this subject, we must pre¬
sent the muscular system in a different view from
what has hitherto been taken of it. The voluntary
nerves, which controul the muscular system, are
sensible of the degree of activity assumed by these
muscles, and there is thus a universal sense spread
over the body, which ministers to the proper organs
of sense, and is, itself, more important than them all.
It is by this property in the voluntary nerves and
muscles, that we are enabled to balance the body in
standing, walking, or running; adjusting the mus¬
cular action, and the state of tension of the limb, to
the gravitation of the body, and so sustaining it in
every variety of posture. We see with what pains,
and after repeated efforts, the child acquires this
power ; and we see how a man is deprived of it in
sickness or inebriety: whilst the utmost perfection
of the same power is exhibited in the rope-dancer.
And what we are thus led to contemplate in the
whole body, may be noticed in the hand, in subser¬
viency to "the sense of touch ; in the tongue, as
subservient to mastication; in the eye, in aid of
vision. It is this faculty which gives us the impres¬
sion of resistance, and consequently of weight, of
solidity, of fluidity, roughness, smoothness, angu¬
larity, &c. Thus, a man depiived of his sense of
touch in his arm and hand, has continued in posses-*
sion of the muscular power, and of the sense of
muscular exertion, and, therefore, he could foim an
estimate of the weight of what he held in his hand,
434
or the muscular power.
Here then is truly that power which gives us the
most accurate perception of things external to the
body, and of all those qualities which would induce
us to call this the geometrical sense ; a term which
has hitherto been given with little propriety to the
sense of touch. *
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, inser¬
tion, or forms of muscles, to favour their power, but
many by which their power is abridged. There are
certain 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 olecranon, 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 for the toes. These are not
the whole, but they are, perhaps, the chief levers in
the human body. In all the other implantations 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 powrer, 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 compen¬
sate for any loss of effect: so, in place of increasing
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 des¬
tined to move : for muscles lose of their effect, by
their being implanted, not behind the joint, but
* See the organs of the senses.
of the muscular power.
43 5
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 per¬
form, so that half their force is lost upon the im¬
moveable 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. Thus, every where
in the human body is power sacrificed to the form
and fitness of the parts, that the joints may be smaller
than the limbs ; that the limbs may be proportioned'
to the body : and beauty, convenience, and velocity
of movement are 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 propor¬
tioned 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 power, by the advantages
of pulleys, and levers, and mechanical helps ; nor is
it in the forms of the parts, that the Infinite Wisdom
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 anticipated 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 Infinite Wisdom,
on which our admiration should chiefly dwell. It is
but the very elements of so deep a subject that can
be delivered here.
f f £
436
of the cellular substance
OF THE CELLULAR SUBSTANCE.
of the membranes, &c.
The subject of this chapter offers some very inte¬
resting facts to our observation, and is both curious
and useful. It is necessary to a correct notion of
physiology, and forms the very foundations of
pathology. The offices of the cellular substance is
so important to life, the changes which it undergoes
in the natural course of life, the remarkable altera¬
tions wrought upon it by inflammation, render it an
important part of any general system of anatomy.
In treating of it, we have an opportunity of doing
justice to our countrymen who have left their repu¬
tation to be guarded by us, and of correcting that
disposition of our youth, who, in search of foreign
novelties, lose sight of the brighter examples they
have at home.
As we advance in our knowledge of the animal
economy, it becomes every day more difficult to
define the difference of solid and fluid ; since in a
living body they are continually alternating; and
since part of that which is fluid in the living body
becomes solid in the dead.
Before describing what a membrane is, we must
point to the peculiarities of the cellular membrane.
In cutting through the skin the cellular mem¬
brane appears with its most common properties.
First of all, let the student distinguish it from the
fat or adipose membrane. The cellular substance or
cellular tissue (tela cellulosa) consists of thin mem¬
braneous processes, which constitute cells or little
cavities. The sides of these cells are bedewed with
a fluid, which, like that of a joint, lubricates, and
produces a fitness for motion, the intention being
that the membranes forming these cells should shift,
and stretch, and accommodate themselves to the
motions of the frame. These cells communicate
freely together. The anatomist traces this cellular
8 •
OF THE MEMBRANES, &C.
tissue every where : it is distinct under the skin ; it
is still more loose and free among the muscles; it
enters into the composition of every part: for as
there must be every where a capacity of motion, as
even the solid viscera must have their pulsating
vessels, they must possess elasticity, and their
mobility and resiliency is given to them by the pro¬
portion of cellular texture which enters into their
composition.
These membranes, thus forming a continuous
series of cells, may be traced into every part; we
have seen it in the bones, around the earth of bone ;
we have seen it forming the sheath for the muscles ;
and in a similar manner, though more delicate in its
texture, it enters into the brain and the eye, and the
nerves ; giving support to all the most delicate organs
of the body.
The cellular substance is common to animal and
vegetable bodies ; and whatever notions we find to
have prevailed in any age with the physiologists of one
department, the same is expressed by the authorities
in the other. Du Hamel asserts that the membranes
of vegetables are composed of organic fibres arranged
parallel to each other, and united by a glutinous
substance. Haller's first word is Jibra, the element.
As the length is to the geometrician, the fibre is to the
physiologist, — out of it he constructs the other parts.
At present there is an attempt, which I consider
equally trifling, to describe the elementary fibre of the
animal body, and to make this fibre to be formed
of globules of a certain diameter, (T^ of a milli¬
metre.) The error I apprehend to be in supposing
the fibre to be the elementary part, instead of the
membrane.
Fluids precede the formation of the solids ; we
would liken it to a soap bubble, which assumes a
solid and concrete form, and which by maceration
may be again dissolved. A principle of vitality pre¬
serves the membrane in its state of aggregation,
and with the loss of life it dissolves — not into
mechanical constituents, but into its chemical ele-
f F 3
OF T.HE CELLULAR SUBSTANCE
.mentis. This vital quality in membranes is shown
by the property of the membranes to retain and
keep separate juices or coloured fluids of an opposite
quality. In the living body there is no transuding
of smell or colour. The intestine, in hernia, does
not taint the fingers, as the same intestine will do in
the dead body. The bile in the living body is
retained within the membrane of the gall bladder ;
in the dead body it stains every surrounding part by
transudation. So, if we cut across a living plant,
we see the juice, of the most opposite nature and
perfectly different colour, flowing from distinct
tubes or cells, and separated by their membranes. I
state this circumstance to show that the simplest
form of membrane has life inherent in it; qualities
which do not result from the fineness of its texture,
but from possessing a quality different from dead
matter; the same quality which retains it in
its proper state of aggregation and organization,
and which when deprived, leaves it to resolve into
its elements.
In opposition to the continental authorities,
headed by the celebrated Bichat, I would teach,
that instead of original molecules and. elementary
fibres being traced into membranes, membranes are
the original and simplest form of the animal frame ;
and that the parts which the French physiologists
pall fibrous parts, are really not so, but are, on the
contrary, resolvable into membranes. They would
have us to believe the tendons to be fibrous ; whereas
nothing is easier than to resolve them by maceration
into cellular texture.
Besides, instead of witnessing any thing like the
weaving and intertexture of their fibres, as if there
were a warp and a woof in the membranes ofthebody,
we see them, in fact, formed very differently ; we see
a fluid effused, as upon the lungs,, coagulating; we see
this coagulum becoming vascular ; we soon discover
it to have become a mass of cellular texture formed
of membranes; and we find, if it continue, that this
texture will at length form cords of adhesion and
1
OF THE MEMBRANES, &C.
m
connection betwixt the surfaces, as firm as any cord,
and of the texture of a true tendon or ligament.
In the same way we may see the membranes formed
by incubation in the egg ; or we may see the gradual
change taking place as the embryo advances. At first,
it looks like a transparent jelly, in which there are
no distinction of parts ; and gradually we see in the
mass white membraneous partitions, as afterwards we
see bones and muscles, &c.; but in all this there is
nothing to countenance the idea of an original fibre
wrought into the several textures of the body.
If any thing more were wanting, we have it in the
degeneration of the fine provisions and proportions
of a joint. Let this joint become inflamed, or
merely stopped in its motion, as in anchylosis, and
instead of ligament and tendon, fascia and cartilage,
synovia and bursa, and all the fine mechanism of
the articulation, you find nothing but the loose cel¬
lular texture. Or, refusing this analytical procedure,
we may view it synthetically; for if a bone be
broken, and that bone, instead of uniting, be per¬
mitted to dangle loose, it will become an artificial
joint; and out of the common cellular membrane, and
the coagulable lymph discharged by the inflamed
vessels, there will be formed membranes and liga¬
ments, and even cartilages and the other appur¬
tenances to a joint.
These considerations make me reject this weaving-
system, as unsuitable to the taste of this country, and
quite at variance with what pathology as well as the
natural anatomy discloses to us.
We shall resume this subject in speaking of the
membranes of the different cavities. At present we
have only to understand, that these extended sheets
of animal matter called membranes, have this common
character through the whole body: 1. That they
have one surface smooth, and bedewed with a secre¬
tion that prevents the surface adhering, and which is
favourable to the motion of that suiface. L2. Th<it
the other surface of the membrane is adhering and
rough, being in truth of the nature of the common
F F 4
440
OF THE TENDONS,
cellular texture. That these membranes have no
termination, but, on the contrary, you may trace them
on from one part of the body to another intermi¬
nably, unless where they form the shut sacs, that is,
the lining membranes of cavities, when, of course,
♦ they are continuous with themselves.
OF THE TENDONS, LIGAMENTS, BURS^, AND FASCIAE,
AND ALL THE PARTS WHICH BELONG TO THE BONES
OR MUSCLES, OR WHICH ENTER INTO THE CONSTI¬
TUTION OF A JOINT.
The bones and muscles themselves are but the
smallest part of that beautiful mechanism by which
the motions of the human body are performed; for
the parts by which the bones are joined to each other,
or the muscles fixed into the bones, are so changed,
and varied in their forms, according to the uses of
each part, as to give a natural and easy shape to the
limbs, security and firmness to their motions, and
lubricity and smoothness to the joints by which these
motions are performed ; and this apparatus deserves
our attention, not merely that we may know the
forms of these joinings, but that we may learn some¬
thing 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 preven¬
tion and cure.
There is a difference in the parts of the human
body, according 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 insen¬
sible, having little action in their natural state, and
little proneness to disease.
The active parts of the system, as we have stated
in the introduction, are the muscles and nerves j the
ligaments, bursae, &c.
441
muscles to move the body, and perform its offices,
each muscle answering to its particular stimuli, and
most of them obeying the commands of the will;
the nerves to feel, to suffer, and to enjoy, to issue
the commands of the will, and to move the muscles
to action : but there is a substance which joins these
parts and connects arteries, veins, nerves, and mus¬
cles, and performs for them every subservient 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 by a continued tissue of cellular sub¬
stance. The tendons, ligaments, periosteum, and
bursae, may be considered as composed of this
cellular substance.
of the forms of the cellular substance.
Under various modifications and shapes, the cellu¬
lar substance 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. 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 of strength, in
health and disease, depends, at least, in some degree,
upon this support. The interstitial cellular sub¬
stance surrounds the fat cells also. This structure,
which is called the adipose membrane, consists of
small bags which do not communicate with each
other, but are for the deposit of oil or fat. The fat
is lodged betwixt the muscles and fills up every
interstice; a want of it is a defect, while a super¬
abundance of it encumbers the body and limbs. And
Haller seems to have believed, that a diseased increase
of it might not only oppress, but almost annihilate
the muscular fibre.
of the tendons,
2. But it is still further essential to a muscle, that i
while it moves, it should neither be hurt itself, nor |
harm the surrounding parts. Therefore, where one ]J
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, pre- (
serving 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 (
as needed, and the cellular substance assumes a new ,
form. The cells are run together into one large cell,
with thicker coats, and a more copious exudation, so
that, being more liberally bedewed with a gelatinous
mucus, it prevents the bad effects of friction, and is
called a bursa mucosa, or Mucousbag. These mucous
bags are placed under rubbing tendons, and chiefly
about the greater joints; some are large, and others
small 5 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 bursas seem to form them
by friction, out of the common cellular substance.
3. It is often useful that an individual muscle
should be enclosed in a tendinous sheath, to give it
strength and firmness, and to preserve it in its shape,
or to direct its force. All muscles, or almost all
muscles, form for themselves individual sheaths, such
as are seen enclosing the supra-spinatus and infra-spi-
natus of the scapula, the biceps humeri, the sartorius,
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 in¬
dividual muscles in their proper places, which other¬
wise might be luxated and displaced. And so some
parts of the trunk of the body, the arm, the thigh, the
leg, are bound each with a strong, smooth, and glisten¬
ing sheath, formed out of the cellular substance, con¬
densed and thickened by continual pressure. It is
hardly to be distinguished in the child ; grows thicker
and stronger as we advance in years and in strength,
ligaments, bursal, &c.
443
and in the arms of workmen it grows particularly
thick and strong, increasing in the back, shoulder or
limbs, according to the particular kind of labour.
I hese 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 mus¬
cles 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 oesophagus, the stomach, intestines,
or bladder. But where tendons pass over bones, or
traverse the joints, their force is concentrated 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 condensation, 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 micro¬
scope, 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 pen-
niform muscles running into their tendon, in a direc¬
tion 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
have no visible nerves, have neither feeling nor self-
motion, nor any endowment by which we should
believe them to be allied to the muscles or nerves;
and many tendons, as the expansion of the palmaris,
may be unravelled into mere cellular substance.*
•x- tendons tire the continuation ot the inteistitial cellu¬
lar membrane of the muscle; and 1 have succeeded in unravel¬
ling them into a web.
444
of the tendons,
The tendon, then, is nothing more than the cel¬
lular membrane, which is in the interstices of the
muscular fibres condensed together. The tendinous
origin of a muscle, for example, may be traced
through the muscle from one extremity to the other
till it is again gathered and twisted into the tendi¬
nous insertion. They may be resolved into loose
cellular membranes by maceration, and many ten¬
dons may be stretched out into a web even without
maceration.
5. The periosteum is merely a condensation of the
common cellular substance, formed in successive
layers : and the tendons are inserted into the sub¬
stance of the periosteum; they mix with the perios¬
teum, and through it are implanted into the bone. In
dissecting a young bone, we tear up the periosteum
along with tendons and without hurting the bones :
but in process of time, the periosteum, and, conse¬
quently, the tendons, are inseparably fixed to the
bones. The periosteum, tendons, fascise, and bursae
mucosae, are all of one substance, and of one common
nature ; they are various modifications of cellular
substance.
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 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 membrane 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
ligaments, bursje, &c.
445
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 peri¬
osteum 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 membrane,
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 performing this office by
the tendons, fasciae, bursas, 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 adja¬
cent parts falling inwards, or being caught 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 across,
when a joint is luxated, and the capsule torn, the
injury is soon repaired by a thickening of the cel¬
lular 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 substance : 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, according to its degree of
motion \ and those ligaments are of the same natuie
446
OF THE TENDONS,
with the first, or bursal ligaments, arise, like tlieni,
from the periosteum chiefly, or indeed are truly but
a thickening of the bursal ligament at certain points.
The universal connection of these parts is now
sufficiently explained, since we have followed the
several forms of cellular substance : 1st. Clothing
the bones with a thick membrane, which, though
insensible, as contrasted with the skin, conveys
blood-vessels, the means of life, to the bones, and is
named periosteum : 2dly, The same periosteum,
thickened and strengthened by the adhesion of sur¬
rounding parts, so as to form the capsules for the
joints: 3dly, The tendon also continued from the peri¬
osteum, and not growing from the muscle, but formed
of the cellular membrane : 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 immediately surrounds the muscle,
cannot be distinguished from the inner surface of
the fascia itself: 6thly, And as for the bursas we
see that they are formed wherever a tendon rubs
over a bone. The upper surface of the bursa is
formed by the tendon which rubs over the bone :
the lower surface of the same bursa is formed by the
periosteum of the bone which it defends : 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 1
have said might be thought to imply absolute insen¬
sibility and total exemption from disease or pain:
LIGAMENTS, BURSiE, &C-
whereas the sensibility of tendons, ligaments, bursa?,
and joints, stands on the same footing with the feel¬
ing of bones: they are insensible in health; not
easily injured ; entering slowly into disease; but
their diseases are equally dreadful from their dura-
tion and from their pain : for by inflammation, their
organization is deranged, their healthy consistence
destroyed, and their sensibility excited in a dreadful
degree.
The tendons of animals have been cut or pierced
with embowelling needles ; they have been cauterised,
they have been burnt with a lighted stick, while the
creatures neither struggled nor shrunk from the irri¬
tation, nor ever gave the smallest sign of pain. Oil
of vitriol has been poured upon each of the parts
belonging to a joint, and a piece of caustic has been
dropped into its cavity, but still no pain ensued;
nay, some have been so bold, may I not say so
vicious, as to repeat these experiments upon the
human body. Without such cruel and inhuman
practices, we do not want opportunities of knowing,
that, in the human body also, the tendons and bursas
have no acute feeling. When we cut open a fascia or
tendinous membrane, there is little pain : when (as
in amputation) we cut the ragged tendons even and
neat, there is no pain: when we snip with our
scissars the ragged tendons of a bruised finger to cut
it off, the patient does not feel: when we see tendons
of suppurating fingers lying flat in their sheaths, we
draw them out with our forceps, or touch them with
probes, without exciting pain. In the old practice of
sewing tendons, there was some danger, but no imme¬
diate pain : when we cut down into the cavity of a
joint, still the pain is but slight. There is very little
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 appear slight in the time, but which
turn out to be the most dreadful sprains. \et, aftei
rupture of the patella, the knee inflames and swells:
after rupture of the Achillis tendon, there is swelling
OF THE TENDONS,
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 dread¬
ful pains: the pain, the lameness, and all the feeling
of inconveniency subside the instant that this car¬
tilage is moved away from betwixt the bones ; and
the joint continues 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 enu¬
merated thus : a joint is composed of the heads of the
bones swelling out into a broader articulating sur¬
face, 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 is a secreting
apparatus within every joint, which pours out a
ligaments, bursie, &c. i4*J
lubricating fluid called synovia; and there is a
bursal membrane reflected from the cartilages that
tip the head of one bone to the edges of the car¬
tilages of the opposite bone: this membrane con^
fines the lubricating fluid, and serves at the same
time to separate what is properly called the joint from
the surrounding parts. This fine bursal or synovial
membrane is surrounded and strengthened by a
membrane of a more ligamentous character, which
serves to bind the bones together. Sometimes this
is called membrana capsularis, and sometimes more
appropriately, ligamentum capsulare : 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
bursas, or mucous bags, which accompany these ten¬
dons, and prevent the violence which their continual
rubbing might do to the bones.
It is remarkable how slowly physiologists have
come to the right knowledge of this matter. The
fact is that all the apparatus of the joint is sensible
cartilage, ligament, and tendon ; but they do not
possess the same kind or degree of sensibility with
the skin and some other parts. They have just the
degree and the kind of sensibility which is suited to
their function ; that is to say, which permits the per¬
formance of their office, yet gives us token of violence
by pain. Their sensibility, like the sensibility of other
parts, being obviously designed as a guard upon
them that we may be careful of such accidents, -and
avoid such exertions, as would be injurious to their
texture. Though seemingly insensible to the common
modes of inflicting pain, yet are the ligaments and
tendons and sheaths sensible to sprains and bruises,
and such kind of injury as they are naturally exposed
to. And when once the process of inflammation is
set up in them, they become the seat of exciuciating
agony." The inflammation of joints, and of all the
parts belonging to them, breaks up the o.ganization
of the part, evolves the feeling, and then in them
also comes disease and violent pain, Ihey aie slow
vol. i. g g
450 OF THE TENDONS, &C.
in entering into action, but once excited, they con¬
tinue 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 excessive action once begun is not easily
allayed. The diseases are infinite to which these
parts are subject. They are subject to dropsical
effusions ; they are subject to gelatinous concretions;
they are subject to slight inflammation, to suppura¬
tion, to erosions of their cartilages, and to exfoliation
corresponding with the dropsies, suppurations, and
mortifications 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 inflamma¬
tion, 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 matter into its cavity. The
inflammation of tendons attends sprain : effusion of
gelatinous matter round them forms ganglion : sup¬
purations in the tendinous sheaths is whitlow: the
inflammation of bursas 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
are : or it is white swelling, which, next to consump¬
tion, is the most dreadful of all scrofulous diseases,
which begins by inflammation in the joint itself, is
marked by stiffness, weakness, loss of motion, and
pain ; which goes on through all the stages of high
inflammation, dreadful pain, destruction of cartilages,
suppurations and spontaneous openings of the joints;
which sometimes stops by an effusion of callus and
concretion of the bones, forming a stiff joint, but
which oftener ends in hectic fever, diarrhoea, morn¬
ing sweats, and extreme weakness; so that the
patient dies, exhausted with fever and pain.
7
4.51
OF THE JOINTS.
Almost every thing relating to the heads and pro¬
cesses of the bones, and every proposition concern¬
ing the motions which they have to perform, has
been already explained, anticipating 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.
I should not wish the readers of this book to be
ignorant of terms, which it is, however, bad taste to
introduce into our discourse, as they are useless and
pedantic, viz.
Dicirthrosis is the free articulation, or proper joint.
When the globular head of a bone rolls in a socket,
it is Enarthrosis.
When plain surfaces meet, as in the bones of the
tarsus, we have the term Arthrodia.
The hinge joint is called Ginglimus.
When a bone turns by rotation it is termed Tro-
choides.
When there is a firm union by cartilage, admitting
no motion, or very little, the term Synchondrosis is
appropriate.
ligaments of the head and spine.
We may compare, in the following 01 dei, the chief
motions of the head and trunk. Fhe head is so
placed upon the oblique surfaces of the atlas^ that it
cannot turn in circles; but at that joint all the nod-
452
JOINTS OF THE HEAD AND SPINE.
ding motions are performed. The atlas rests so upon
the vertebra dentata, that there all the turning mo¬
tions are performed. The neck and loins have their
vertebras so loosely framed, with such perpendicular
processes and easy joints, that there all the bending
motions are performed, while the back is fixed, or
almost fixed, by its connection with the ribs, and
by the obliquity and length of its spines; and
though, upon the whole, the spine turns many de¬
grees, yet it is with a limited and elastic motion
where the whole turning is great, but the move¬
ment of each individual bone is small.
To secure these motions, we find, the occipital
condyles received into hollows of the atlas, where
the oblique position of the condyles secures the
joint, the occipital condyles looking outwards, the
articulating surfaces of the atlas looking towards
each other, the occiput set down betwixt them, so as
to be secured towards either side, and the obliquity
of the joint 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 vertebras, and being fixed into a roughness at
the root of the condyle. We find a flat membraneous
ligament, which extends from the ring of the atlas
to the ring of the occipital hole, closing the inter¬
stice betwixt the occiput and the atlas : it is con¬
founded at the sides with the capsules of the articu¬
lating 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 membraneous behind.
We find the atlas tied to the dentata by a more
complete order of ligaments. These are, 1st, (as
betwixt the atlas and dentata,) regular capsules, or
bags, fixing the condyles of one vertebra to the
* This is part of what Winslow called ligamentum infun-
dibiliforme, a funnel-like ligament, joining the first vertebra
to the occiput.
joints of the head and spine. 453
( - *
condyles of the other. 2dly, A cross ligament*
which, crossing the ring of the first vertebra, 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 dentata turns in
the ring of the atlas, and is bound by the ligament;
and this rolling* of the atlas upon the axis of the
dentata 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.f
All the other vertebrae have another kind of arti¬
culation ; to which the occiput, atlas, and dentata
are the only exceptions, for their motions are par¬
ticular, and quite different from the rest. The atlas
and dentata bend, turn, and roll by connections re¬
sembling the common joints of the body ; but the
other vertebras are united, each by its interver¬
tebral substance, to the bones above and below ;
they are also united by their articulating processes to
each other : each articulating process is held to an¬
other by a distinct capsule ; each intervertebral sub¬
stance is secured, bound down, and strengthened by
strong ligaments ; for the intervertebral substance,
which of itself adheres very strongly to the peri¬
osteum, and to the rough socket-like surface upon the
body of each vertebra, is further secured by a sort
* Viz. 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 dentata, and into the occipital hole, so as to enclose
the tooth-like process of the dentata in a capsule.
f 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 and strong.
g g 3
454
joints of the head and sl'ine.
of cross ligaments, 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 in¬
tervertebral substance, they strengthen it. These
ligaments cross each other over the interstice betwixt
each vertebra, and are very strong in the lumbar
portion. They are regular and shining, and are
named intervertebral crucial ligaments.
The spine is further secured by a general liga¬
mentous or tendinous expansion, which goes over the
fore parts of all the vertebrae, from top to bottom of
the spine. It begins at the fore part of the atlas ; it
almost passes the body of the dentata, or is but very
slightly attached to it. It is at first pointed, small,
and round ; it begins to expand upon the third ver¬
tebra of the neck, so as to cover almost all its body.
It goes down along the bones, chiefly on their fore
parts, 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 interruptions 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 con¬
tinued, that it is considered 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
undefended, rough and dangerous to the spinal mar¬
row, if internal ligaments were not added to these.
The rings of the vertebrae are held at a considerable
distance from each other by the thickness of the
* The LIGAMENTUM COMMUNE ARTERIUS, FASCIA LONfcl-
TUPINALIS ANTERIOR, FASCIA LIGAMENTOSA,&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.
joints of the head and spine.
4 55
intervertebral substance, and by the corresponding
length ot the oblique processes ; but this space is
filled up by a strong flat ligament of a yellow colour,
which goes from the edge of one ring to the edge
of another, and so extending from the articulating
processes, backwards to the roots of the spinous
processes, they fill up all the interstice, complete
the canal of the spinal marrow, and bind the bones
together with great strength* : these are assisted in
their office of holding the vertebras together, by a con¬
tinuation of the same ligament, or of a ligamentous
membrane connected with it, which runs all the way
onwards to the ends of the spinous processes, where
they are strengthened by accidental fasciculit: and
in the middle vertebrae of the back, but not of those
of the loins or neck, similar ligaments are found also
betwixt the transverse processes.t
Next there is another internal ligament, which is
not interrupted 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 vertebrae ; at the interstice of every vertebra it
spreads out broad upon the intervertebral substance,
doing the same office within that the intervertebral
crucial ligaments do without. It is broader above ; it
grows gradually narrower towards the loins. Although
it is called a vagina, or sheath, it does by no means
surround nor enclose the spinal marrow, but is en-
* They are named the ligamenta subflava crurum pro-
CpSSUUM SPIN O SO RUM.
f These are named the membranje interspinales, and
LIGAMENTA APICIUM SPINOSORUM Or FUNICULI LIGAMEN1OSI.
The ligaments which tie the points of the spines, running from
point to point, make a long ligament which stretches down all
the spine.
J Called ligamenta processuum transversorum, and found
only from the fifth to the tenth vertebra ot the back.
$ Fascia ligamentosa postica, fascia longiiudinalis
POSTICA, ligamentum commune poster1us.
G G 4
156
joints of the head and spine.
tirely confined to the covering of the bodies of the
vertebrae, never going beyond the setting off of the
articulating surfaces, or the place where the nerves
go out. It adheres firmly to the bones, and does
not belong at all to the spinal marrow. It should
rather be called a ligament for the bones, than a
sheath for the medulla. The anterior ligament pre¬
vents 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 into the canal of the verte¬
brae, 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 ap¬
paratus ligamentosus extends from the edge of the
occipital hole to the fourth vertebra of the neck,
where it ends. Its chief use is also as a ligament,
merely fixing the head to the neck. The dura
mater is within it, immediately enclosing the spinal
marrow. The ligaments which I have just named
may be well enough allowed to be " at once liga¬
ments for the bones, and a sheath for the medulla."
But there is no such sheath as that called ligamen-
tum 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 connection 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 con¬
nection is by the loosest cellular substance.
joints of the head and spine.
457
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 the long small head,
or condyle, of the jaw, placed across the long branch,
or condyloid process. 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 arti-^
culating surface; that the common 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 zygomatic process. When there is luxation of the
jaw there 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 car¬
tilages in the joints of the clavicle, wrist, knee, and
jaw, because the motions are continual and rapid.
The moveable cartilage is thin in its centre, and
thicker towards its edges, by which it rather deepens
than fills up the hollow of the joint. It corresponds in
shape with the head or condyle of the jaw, and with
the hollow of the temporal bone. It moves with every
motion of the jaw, facilitates the common motions,
and prevents luxation. Its edges all round are
458
JOINTS OF THE HEAD AND SPINE.
fixed down by ligaments, but the joint is still more
strongly secured by lateral ligaments on the inside
and outside, and by the strength of its pterygoid and
temporal muscles, which are inserted close round the
joint. It is the muscles which prevent luxation ; and
it is their action also that makes luxation, when it has
happened, so difficult to reduce. We may mention
here a ligament or strong band of fascia that passes
from the styloid process to the angle of the jaw, and
sends a slip downwards also to the body of the os
hyoides, as it were to suspend it.
The Ligaments of the jaw are these:
1. Membrana Articularis.
2. Ligamentum Cartilaginis Intermedial.
3. Ligamentum Maxillae Laterale Internum.
4. Ligamentum Maxillae Laterale Externum.
5. Ligamentum inter Maxillam et Processum Styloideum.
After these descriptions of the ligamentous con¬
nections of the spine the student may require some
more precise table; for example :
LIGAMENTS OF THE VERTEBRAL COLUMN,
SEEN EXTERNALLY.
First, as standing by itself peculiar, the intervertebral substance.
1. Ligamenta Capsularia.
2. Ligamenta Crucialia ligamentorum intervertebralium.
3. Ligamentum Commune Anterius, or Fascia Longitudina-
lis Anterior.
4. Ligamenta Apicium Processuum Spinosorum, or
Funiculi Ligamentosi.
5. Ligamentosae Interspinals membranae*
6. Ligamenta Processuum Transversorum.
LIGAMENTS SEEN ON MAKING THE SECTION OF THE SPINE.
1. Ligamentum Commune Posterius, or Fascia Longitudina-
lis Posterior.
2. Ligamenta subflava Crurum Processuum Spinosorum.
LIGAMENTS BETWIXT THE HEAD AND UPPER VERTEBRA.
1. Apparatus Ligamentosus.
2. Ligamentum Infundibiliforme.
3. Ligamenta Capsularia.
JOINTS OF THE HEAD AND SPINE.
459
4. Ligamentum Perpendiculare.
5. Ligamentum Transversale — Appendices ejus.
6. Ligamenta Lateralia Moderatoria.
These ligaments of the spine, which strengthen
and supportrbones of very delicate and spongy tex¬
ture, are very subject to scrofulous inflammation.
The transverse ligament has been burst, and the
tooth-like process of the second vertebra has
crushed the spinal marrow, with instant death
ensuing.
A diastasis, or partial separation of the vertebras
of the neck, with laceration of ligaments, is no
unfrequent effect of falling from a height on soft
ground.
A subluxation of the atlas from the vertebra den-
tata, has occurred from suddenly turning the head,
and death has attended the attempts at reduction.
Subluxation of the lumbar vertebrae, that is dis¬
placement of the articulating processes, I have often
seen.
Total dislocation of the bodies of the vertebras is
a very rare accident; yet there is an instance in my
collection, where the child lived more than a year,
and died at last of croup.
After all twists and injuries of the ligaments of
the spine, although there may be no dislocation, we
have reason to be apprehensive of inflammation of
the ligaments or general sheath of the spinal marrow.
RIBS.
The ribs have two joints, and a hinge-like motion,
rising and falling alternately, as we draw in or let
out Sie breath. The two joints of the ribs are thus
secured : First, the proper head of the ribs being
hinged upon the intervertebral substance, and touch¬
ing two vertebras, 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;
460
joints of the head and spine.
it is radiated without, so as to expand pretty broad
upon the sides of the vertebras, and has a sort of
division, as if into two fasciculi, the one belonging
to the vertebra above, the other to the vertebra
below: they gradually vanish, and mix with the
periosteum upon the bodies of the vertebrae; these
are named ligamenta capitellorum costarum, as
belonging to the little heads of the ribs.
The back of the rib touches the fore part of the
transverse process, and is articulated there : conse¬
quently 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 trans¬
verse 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 thence named ligamentum transversarium
externum ; another, rather longer, comes from the
inner face of the transverse process above, goes down,
and a little round the neck of the rib is implanted
into the edge of the rib, and is named ligamentum
transversarium internum : another small ligament
exactly opposite to this, going from the outside of the
transverse process into the neck of the rib, upon its
back part, and crossing the last, is also very regular ;
it is called ligamentum cervicis cost;e externum :
and other subsidiary ligaments from different points
assist these or supply their place.
The ribs are fixed into the sternum by their car¬
tilages, each of which has a round head, a distinct
socket, a regular capsule, and ligaments which expand
and are scattered upon the surface of the sternum,
much in the same way that the ligamenta capitelli
expand upon the bodies of the vertebrae : a tendinous
membrane also binds the cartilages of the ribs one to
another, crosses over the interstices, and so covers
the intercostal muscles with a sort of fascia; and
the whole surface of the sternum and that of the
cartilages is covered with this tendinous expansion,
which belongs confusedly to the origins of the pec-
joints of the shoulder, arm, and hand.
toral muscles, to- the ligaments of the ribs and
sternum, and to the periosteum of that bone.
LIGAMENTS BETWIXT THE RIB AND THE SPINE.
1. Ligamentum Capitelli Costae Anterius.
2. Ligamenta Capsularia Capitelli.
3. Ligamentum Capsulare (of the union with the
transverse process).
4. Ligamentum Externum Transversarium.
5. Ligamentum Transversarium Internum.
6. Ligamentum Cervicis Costae Externum.
ANTERIOR EXTREMITY OF THE RIBS AND STERNUM.
1. Ligamenta Radiatim Disjecta.
2. Ligamenta Transversa.
3. Membrana Sternalis.
JOINTS OF THE SHOULDER, ARM, AND
HAND.
clavicle sternum scapula.
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 accord¬
ingly it has, like the condyle of the jaw, a small
moving cartilage, which rolls betwixt this head and
the sternum. The cartilage is thin, and of a mem¬
braneous nature ; it is moveable in some degree, yet
it is fixed by its edges to the head of the clavicle
and the socket of the sternum. This joint is en¬
closed 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 ster¬
num, like the ligaments of the ribs ; and they cross
and cover the sternum, so that the ligaments of the
opposite sides meet: and this meeting forms a cord
462
joints of the
across the upper part of the sternum, which is named
interclavicular ligament. TllUS is the clavicle
fixed to the sternum, and another broad ligament
also ties it to the first rib, viz. the ligamentum
rhomb oides.
The joining of the clavicle with the scapula is by
the edge of the flat clavicle, touching the edge of
the acromion process with a narrow but flat articu¬
lating surface : both surfaces, viz. of the acromion
and of the clavicle, are covered with a thin articu¬
lating cartilage : in some subjects a moveable car¬
tilage 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 process : the clavicle, as
it passes over the point of the coracoid process, is
tied down to it by ligaments of considerable strength;
one comes from the root of the coracoid process to
the clavicle, and is called ligamentum commune
conoides ; another from the point of the coracoid
process, is implanted into the lower or inner edge of
the clavicle, and is named ligamentum commune
trapezoides — trapezoid, on account of its square
form, and commune, because it goes from the sca¬
pula 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
posterius is of less importance, being that which
completes the notch of the scapula into a hole, and
gives attachment to the omo-hyoideus muscle.
The acromion scapulae is sometimes separated
from the end of the clavicle, and the accident may
be mistaken for a dislocation of the humerus.
shoulder, arm, and hand.
4 63
The sternal extremity of the clavicle is sometimes
dislocated. A case presents to me while this is going
to press. It is an accident very easily distinguished,
for the great tubercle on the end of the bone rises
like a tumor, and the part of the mastoid muscle
arising from it is also raised, and seems as if, by its
contraction, it pulled up the bone.
shoulder-joint.
The shoulder is one of the most beautiful joints,
loose and moveable, very free in its motions, but very
liable to be displaced. To form this joint, the
humerus has a large round and flattened head ; the
cavity of the scapula*, which receives this head, is
oval, or triangular, small and very shallow; it is
eked out with a thick cartilaginous border, which
increases the hollow of the socket, but still it is so
shallow, that the humerus cannot be so truly said to
be lodged in the glenoid cavity as to be laid upon it.
Its capsule or bag is very loose and wide, coming
from the edges of the glenoid cavity, and implanted
round the neck of the bone : the joint is richly be¬
dewed with synovia, which is partly secreted by a
fimbriated organ, the common organ for this secre¬
tion through all the joints, and by a thinner exuda¬
tion from those extreme arteries which terminate,
with open mouths, upon the internal surface of the
capsule.
By the shallowness of its socket, and the largeness
of its head, by the looseness of its capsule, by all the
forms and circumstances of its structure, the shoulder
is exceedingly loose, and very liable to be displaced:
it has this loose structure, and superficial socket, that
its motions may be free, but seldom is there any
great advantage gained in the human body, without
a counterbalance of weakness and danger ; and every
where in the limbs we observe that a joint is weak
and liable to luxation in proportion as its motions
* It is called a glenoid cavity, from the Greek name of a joint,
and the name is not absolutely appropriated to the scapula.
joints of the
are free and large. Yet the shoulder-joint is not
without some kind of defence; 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:
therefore a ligament extends from the coracoid to the
acromion process, (ligamentum propiuum triangu-
lare scapula,) which completes the defences of the
joint above, and at its inner side. The capsule is
perforated by the long tendon of the biceps muscle*,
to arrive at which it takes a long course through a
sheath which passes over the groove in the bone
which lodges the tendon ; and there comes also from
the point of the acromion process an additional liga¬
ment, which adheres to the capsule : but the cir¬
cumstance from which the chief strength of the
shoulder-joint is derived, is the insertion of the foul-
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 holds 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 luxation of the
humerus, from an internal cause ; and the shoulder
cannot be luxated by a fall, without such violence
as tears up the tendons of these muscles. We must
add to this anatomy of the joint, that it is surrounded
by numbers of bursas or mucous bags : one under
the tendon of the subscapulars ; one under the
short head of the biceps muscle; one betwixt the
coracoid process and the shoulder-bone; and one
* The capsular membrane is perforated, while the thin synovial
membrane is reflected upon the tendon.
shoulder, arm, and hand.
465
andei the acromion process of the scapula, exceed¬
ingly laige : and these are so fairly parts of the joint,
tiat veiy commonly they open into it with commu¬
nications, either perfectly natural, or at least not
hurtful, either originally existing, or formed by con¬
tinual friction. It should also be remembered, that
the long tendinous head of the biceps muscle comes
fiom the margin of the socket, directly over the ball
of the os humeri, and through the capsule, and
answers the purpose of a ligament.
recapitulation of the ligaments about the
shoulder.
(Between the clavicle, sternum, and first rib).
1. Membrana Capsularis.
2. Cohaesio Fibrarum Externa.
3. Connectio Cartilaginis Interarticularis.
4. Ligamentum Interclavicular.
5. Ligamentum Rhomboides [betwixt clavicle and rib.]
(Between the clavicle and scapula).
1. Ligamentum Capsulare.
2. Ligamenta Radiata [on the point of the acromion].
3. Ligamentum Commune Trapezoides.
4. Ligamentum Commune Conoides.
(Ligaments proper to the scapula).
1. Ligamentum Proprium Triangulare, seu Deltoides.
2. Ligamentum Proprium Posterius.
(Ligaments of the shoulder joint).
1. Membrana Capsularis [strengthened by the tendons of
muscles].
The most frequent dislocation is that of the
humerus from the glenoid cavity of the scapula.
elbow.
The elbow-joint is formed by three bones; the
humerus, radius, and ulna : the ulna bends back¬
wards 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, roiling in circles; its
vol. i. h h
460
joints of the
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 humerus. The whole com¬
poses 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 considered or known.
The radius and ulna are united principally by the
interosseous ligament, which, as it extends in the
whole length of the bones, has great strength.
Towards the elbow this ligament is deficient for a
space, and it is perforated by vessels. The chorda
trans vers alis cubiti is an oblique slip of ligament
which passes from the tubercle of the ulna obliquely
downwards and across to the tubercle of the radius.
ligaments of the elbow-joint.
The general capsule arises from the humerus,
from both the tubercles, and all round the two hol¬
lows which receive the olecranon and coronoid pro¬
cesses of the ulna; it is implanted again into the tip
of the olecranon, and all round that sigmoid cavity
of the ulna which receives the lower end of the
humerus, and all round the edge of the coronary
process. It is also fixed round the neck of the
radius ; it comprehends, in one bag, the humerus,
radius, and ulna; and unites them into one joint,
performing two motions, viz. flexion and extension
by the ulna, and rolling by the radius; the joint is
lubricated and protected by synovia and by fat*,
which is found chiefly about the olecranon : and that
the bones may be further secured, additional liga¬
ments are spread out upon them, which are all with¬
out 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
* The oil contained in the adipose membrane never exudes
in the living body, and cannot lubricate.
shoulder, arm, and hand.
this is one of the purest) to have its capsule strength¬
ened at the sides ; and the sides of this, the elbow-
joint, are strengthened by two fasciculi, or liga¬
mentous bands, which, coming from the tubercles of
the humerus, spread a little upon the capsule, and
adhere to it like part of its substance. One, from the
outer condyle, spreads upon the neck of the radius,
and sends a strong division to be attached to the
rough spine of the ulna, which is near the lesser
sigmoid cavity of the ulna. This is of course the
external lateral ligament. Another ligament,
from the inner 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 liga-
mentum coronarium or annulare, because it en¬
circles the neck of the radius ; annulare or orbicu-
lare, 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 circle ; and so, having turned over the neck of the
radius, is inserted 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
* I see another ligament behind the internal lateral ligament,
viz. arising from the internal condyle, and inserted into the
side of the olecranon. There are in truth two internal lateral
ligaments, and their operation is not merely to confine the 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 of the fore-arm.
ii ii 2
468
joints of the
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 ligament of the
radius, and are known by the general name of acces¬
sory ligaments of the coronoid ligament, as the
lateral ones are known by the name of accessory
ligaments to the capsule. *
RECAPITULATION.
1. Membrana Capsularis.
2. Ligamentum Laterale Internum.
3. Ligamentum Laterale Externum.
4. Ligamentum Orbiculare.
5. Ligamenta Accessoria.
The ulna is sometimes dislocated from the troch¬
lea of the humerus. The head of the radius may be
separated from the lesser sigmoid cavity of the ulna.
But this part of the ligamentous apparatus of the
joint is more apt to be sprained, to swell, and thence
be mistaken for dislocation of the head of the radius.
wrist.
The wrist is one of the most moveable joints in
the body, having the strength of a mere hinge-joint ;
(because it is almost a strict hinge, by the connection
of the long ball of the carpus with the long hollow
of the radius,) and having, at the same time, all the
properties of the most moveable joint by the free
turning of the radius, without the weakness which is
peculiar to the circular and free movingjoints. 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 re-
* But the capsule ought to be called membrana capsularis;
it is not a ligament, and these which are called accessory arc
proper ligaments. The ligament which is on the fore part of
the joint, and which runs towards the Ligamentum Annulare 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 back of the joint, Accesso¬
rium Annulare Posticum.
SHOULDER, ARM, ANl) HAND.
ceives this ball: the end of the ulna does not pro¬
perly enter into the cavity of the wrist, but its end,
or little round head, is covered with a moveable car¬
tilage, and that cartilage represents the end of the
ulna. It is called cartilago intermedia triangu¬
laris. ]\ow, this first joint, viz. of the scaphoid and
lunated bones, the head of the radius, and the move¬
able 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
implanted 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 011
one side an additional ligament for the carpus ; on
the other, it forms the floor of the tendinous sheath,
a smooth and lubricated 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
ligaments; for although the wrist-joint is not accu¬
rately a hinge, yet it partakes most of that character,
and the ligaments 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
lacunae or ducts which secrete the synovia.
2. The articulation by which the hand performs all
its turning motions is that of the radius with the ulna :
hh3
470
JOINTS OF THE
tuis is set apart altogether from the general arti¬
culation 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 CAPSULAR1S 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 adjoining 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 received 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
regular capsular ligament within, and by flat cross
ligaments without, or rather by many bundles of
ligaments, which cross each other in a very com¬
plicated manner, and the little flat and shining fas¬
ciculi give the whole a radiated or star-like form. #
But there is a very particular ligament which descends
from the styloid process of the ulna to the carpus,
the use of which will be understood, if we rest upon
our hands, for then the whole weight of the body is
sustained by it.
* 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 ligamenta, brevia, obliqua,
transversaria, and propria ossium carpi; for they do in
fact cross and transverse the carpus in every possible direction.
SHOULDER, ARM, AND HAND.
I he metacarpal bones are also joined to the carpal
in one row, by a line of joints, which are as one joint:
besides their common capsule, the metacarpal of each
finger lias its peculiar 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 securely tied
by ligaments to one or two of the bones of the
carpus * ; and at their heads, where the fingers are
implanted upon them, forming the knuckles, they are
again tied by flat ligaments, which go from head to
head of the metacarpal bonest, 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.
recapitulation.
1. Funiculus Ligamentosus Ulnae.
2. Membrana Capsularis.
3. Membrana Sacciformis.
4. Ligamentum Mueosum.
5. Ligamentum Cartilaginis Intermedin.
6. Ligamentum Transversale Carpi Proprium.
7. Ligamentum Commune Carpi Dorsale.
8. Ligamentum Rhomboides.
9. Ligamenta Brevia.
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 head, to be
a circular and free moving joint; but it is restricted,
by the forms of its ligaments, to the nature of a
hinge-joint; for each finger-joint is included first in
a fair round capsule, or bag, of the ordinaly foim, but
* And these also are named according to their several direc¬
tions, ligamenta articulari a, lateralia, recta, per¬
pend icul aria, &c.
-j- These are named the ligamenta interossea.
H H 4
joints of the shoulder, &c.
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 bursas
mucosas, as it is indeed, like them, a shut sac. 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 burs®, to prevent the bad consequences
of friction, are put both betwixt the cross ligament
and the tendons, and also betwixt the tendons of the
uppermost 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 a 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 bursae. 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 con¬
tinued canal; these are named the sheaths and
1
joints of the pelvis, &c.
annular ligaments, or cross ligaments * of the
fingers, and are of the same nature with the bursae.
Besides these, there are no distinct bursae on the
fingers, but there is one of considerable size at the
root of the thumb, t
JOINTS OF THE PELVIS, THIGH, LEG,
AND ANCLE.
of the pelvis.
The ligaments of the pelvis may be divided into
three distinct sets: — 1st, those which unite the
vertebras and the sacrum : 2d, those which pass from
the os ilium to the vertebrae : and 3d, those which are
between the ilium and the sacrum. The ligaments
which are at the upper part are of trifling importance,
compared with those which form the outlet of the
pelvis.
The ligaments connecting the last lumbar verte¬
brae to the sacrum are similar to those of the spine ;
so we need not describe them here.
The ilium is held in connection with the vertebrae,
by two principal ligaments. The one passes from
the crest of the ilium to the transverse process and
body of the last lumbar vertebra, and is called li-
gamentum- anticum superius. This ligament is
often of a triangular form, owing to a small portion
of it being prolonged up to the transverse process of
the fourth vertebra. The other passes from the
same point of the os ilium to the junction of the last
vertebra with the os sacrum, and it is named li-
gamentum anticum inferius.
The principal bond of union between the os ilium
and the sacrum is at the sacro iliac symphysis, The
* llgamenta vaginalia, ligamenta crucia1a, l'ha"
langum, &c.
-j- Vide Monro's Bursae Mucosae.
joints of the pelvis,
scabrous surfaces of tnese two bones are joined by
means of a ligamentous and cartilaginous substance,
called the sacro iliac ligament ; it holds them
firmly together, and allows of no motion between
them. On the fore and back part there are acces¬
sory strengthening bands : those on the back part
have been called generally ligamenta dorsalia
vaga ; yet some have chosen to describe them sepa¬
rately, with the additional terms, longum, breve,
laterale, annexed to them.
The ligamentum sacro-ischiaticum majus 01'
posterius arises from the posterior part of the crest
of the ilium, and from the sides and posterior part of
the sacrum and os coccygis, and is attached to the
tuberosity of the ischium. A portion of this ligament
runs up towards the superior posterior spinous process
of the ilium, and is called the superior appendix :
but another more important portion, having con¬
nection with the fasciae of the perineum, can be traced
along the inside of the tuberosity of the ischium to
the ramus of the os pubes: this is called the pro-
ductio falciformis of wlnslow. The ligamentum
sacro-ischiaticum minus 01* anterius crosses the
last; it arises from the os sacrum and os coccygis,
and is inserted into the spinous process of the
ischium. The tendon of tli£ obturator interims
muscle passes through the opening left between
these two ligaments.
The os coccygis is united to the sacrum by liga¬
ments resembling those of the spine, or by the con¬
tinuations of those lying on the back of the sacrum :
tlie LIGAMENTA LONGITUDINALIA.
The bones of the pubes are united by an inter¬
mediate cartilage, which has great strength, and has
a considerable resemblance in its structure to the in¬
tervertebral substance which joins the bodies of the
vertebrae together. This junction has the name of
symphysis or synchondrosis ossium pubis ; and it
is strengthened by a ligament which embraces it all
round, and is called annulus ligamentosus. The
connection of the ossa pubis is further strengthened
1.3
thigh, leg, and ancle.
by the triangular ligament, which passes across
from the ramus of each bone, and to which the
urethra is suspended. The obturator foramen is
closed by the membrana obturans, except a small
portion at its upper part, through which the obturator
artery and nerve pass.
of the hip-joint.
The acetabulum, which is rough in the naked
bone, is naturally 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 is filled up by a strong carti¬
laginous ligament, which goes across this gap, from
the one point to the other, and from its going across
is named the ligamentum labri cartilaginei trans-
versale. * The capsular ligament of the hip-joint is
the thickest and strongest of all the body. It is, like
other capsules, a reflection and thickening of the
periosteum ; the periosteum coming along the out¬
side of the bone, leaves it at the edge of the socket..
The periosteum, or rather perichondrium from the
inside of the socket, comes up to the edge, and meets
the outer layer. They unite together, so as to form
the general capsule enclosing the ring-like cartilage,
which tips the edge of the socket between them.
* 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. ligamentum transversale internum ct
externum.
JOINTS OF THE PELVIS,
This ligament encloses all the bones from the edges
of the socket to the roots of the trochanters, em¬
bracing not only the head, but the neck of the thigh¬
bone. The outer-plate, continuous with the peri¬
osteum, is thick and strong, and is assisted by much
cellular substance condensed round it, and itisfurther
thickened by slips which come from the iliacus,
rectus, and other muscles which pass over the joint,
while the external plate of the ligament lines the
whole with a soft and well lubricated coat.
In addition to this general capsule, there are two
internal ligaments, 1st, the round ligament, as it is
called^ which comes from the centre of the socket
to be fixed into the centre of the ball of the thigh¬
bone. It' is not round, but flat or triangular. 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 almost 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 liga¬
ment, and in the bottom of the socket, there is left
a pretty deep hollow, which is said to be filled up
with the synovial gland. It is wonderful how easily
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 tro¬
chanter ; yet there is no distinct gland to be found.
There is a fringed and ragged mass lodged in the
bottom of the socket, hanging out into the hollow,
and continually rubbed by the ball of the thigh-bone
in its motions : the fringes and points certainly are
ducts from which we can squeeze out synovia; but it
is by no means proved that they belong to a synovial
gland, and it looks rather as if the ducts were them-
thigh, leg, and ancle.
selves the secreting organ, like the lacunae, or
mucous bags in the tongue, or in the urethra, vagina,
oesophagus, and other hollow tubes. Such a struc¬
ture is fitter tor suffering the strong pressure and
continual action of the thigh-bone, than any deter¬
mined gland. We see, then, nothing but mucous-
like ducts of a fringed form, hanging down from this
hollow in the cavity of the joint, a quantity of fat
accompanying these fringes, and a pappy synovial
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 massse adiposae
glandulosa; and this may be considered as the con¬
tinued inflection of the softer internal lamella of the
capsule, which not only lines the socket, but is re¬
flected over the central ligament, and over the globe
of the thigh-bone, covering them also with a delicate
synovial 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 fimbriae,
with the general serous exudations, are mixed and
blended for lubricating the joint.
This capsule, which is naturally the thickest and
strongest in the body, almost a quarter of an inch in
thickness, is further strengthened by many additions;
for a slip of very strong tendinous or ligamentous
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 fore
part; the smallest of the glutsei 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,
JOINTS OF THE PELVIS,
which is condensed so as to strengthen the capsule,
forming at the same time a large bursa mucosa,
betwixt their tendinous fibres and the joint. That
tendon of the rectus muscle which comes from the
margin of the socket, lies upon the outer side of the
capsule, adheres to it, and strengthens it. The secu¬
rity of the hip-joint seems to depend more upon the
strength of its capsular ligament, than that of almost
any other joint.
RECAPITULATION OF THESE LIGAMENTS.
1. Ligamentum Capsulare.
2. Ligamentum Accessorium Anticum.
3. Ligamentum Teres.
4. Ligamenta Labri Cartilaginei.
5. Ligamentula Massae Adiposse,
The head of the thigh-bone is subject to disloca¬
tion upward and outward, and also to displacement
downward and forward.
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 ancle, 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 ligaments 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 con¬
tinual 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.
thigh, leg, and ancle.
1 he bones which compose this joint are the tibia,
thigh-bone, and patella; and they are united by many
ligaments, both within and without the joint.
1. The capsule of the knee is naturally thin and
delicate. This thin capsule comes from the fore part
of the thigh-bone, all round the articulating surfaces,
whence it goes downwards by the sides of the con¬
dyles : from this origin it is inserted into all the edge
of the rotula, and in such a way as to keep the rotula
properly without the cavity of the joint, the synovial
membrane 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 hamstrings ; on its fore part, it
is strengthened by the general fascia of the thigh,
which goes down over the knee, and being there
reinforced both by its adhesion to the bones, and by
the broad expansion of the vastus internus, sartorius,
biceps, and other muscles which go out over the
patella, it adheres to the capsule, and makes the
whole very strong ; besides which, there is a liga¬
ment, which, lying in the ham, upon the back part
of the capsule, is named, in compliment to Winslow,
ligamentum posticum Winslowii. It is a ligament
somewhat resembling the lateral ligaments of the
elbow. It arises from the outer condyle, goes ob¬
liquely 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 accounted
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 lateial ligaments
* Often it is irregular, or in straggling fibres ; but I have never
found it wanting.
480
joints of the pelvis,
are particularly distinct, and can be raised from the
capsule ; on the inner side of the joint, there comes
down from the internal condyle 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 longius, to distinguish it from the next;
for behind this first external ligament, there arises
a little lower from the same condyle, along the outer
head of the gastrocnemius muscle, a ligament which
is called the ligamentum laterals externum bre-
vius, and it is not shorter only, but so spare 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.*
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 crucial ligaments.
The posterior crucial ligament is more perpen¬
dicular ; it arises from the hollow betwixt the con¬
dyles of the thigh-bone, and is implanted into a
roughness on the back of the tibia, betwixt its two
cup-like hollows, and behind the tubercle which
* 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 ancle.
481
divides these hollows from each other. While the
posterior arises rather from the internal condyle, the
anterior ligament arises properly from the external
condyle, passes obliquely over the tuber, in the arti¬
culating surface of the tibia, and terminates in the
cup-like hollow. The effect of these two ligaments
is more particular than is commonly observed ; 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 anterior ligament is extended;
when the leg is stretched out, the posterior ligament
is extended; they both are checks upon the motions
of the joint: the posterior ligament prevents the leg
going too far forwards, the anterior ligament pre¬
vents it being too much bent back upon the thigh.*
4. The most admirable part of the mechanism of
this joint, is the two semilunar cartilages. They
are so named from their semilunar form; they lie
upon the top of the tibia so as to fill up each of
them one of the hollows on the top of that bone.
They are thicker towards their convex edges, thinner
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 enclo¬
sing the fimbriated ends of the mucous ducts. These
fimbria, and fatty bundles, are formed chiefly round
* 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. Tliie posterior ligament
comes from the root of the internal condyle, and depth of the
semilunar notch, anterior to the centre of motion of the femur
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.
vol. i. 1 1
joints of the pelvis,
the circumference of the patella, commonly sur¬
rounding 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 ; there is one
principal bed of this fatty matter at the lower part
of the patella and around the commencement of its
ligament.
These masses of fat lie covered by the delicate
internal surface of the capsule, and the mucous
fimbriae are also covered by it.
The inner surface of the capsule is so much
larger than the joint which it lines, that it makes
many folds or lurks, and several of these are distin¬
guished by particular names. Thus, at each side of
the patella there are two such folds, the one 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
fimbriated ducts in their place (viz. the hollow
betwixt the condyles, where they are least exposed
to harm) ; thence it has been long named the liga¬
mentum mucosum. The internal membrane of the
joint covers also the semilunar ligaments, as a peri¬
chondrium ; 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 ligaments, two for the horns of each car¬
tilage. These tags by which the four points of the
lunated cartilages are tied, are named the ligamenta
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 fore part of the knob of the tibia, and ties the
fore parts of these two cartilages to each other. It
is named ligamentum transversale commune, be-
thigh, leg, and ancle.
483
cause 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
security, these cartilages also adhere to their outer
circle, or thick edge, to the internal surface of the
general capsule of the joint by the ligamentum
coronarium, and that again adheres 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 extensor muscles and the
fore part of the thigh-bone, which is no less than
three inches in length. There is a smaller bursa
about an inch below the patella, and under the liga¬
ment of the patella, protecting it from friction, upon
the head of the tibia. These bursas, I am persuaded,
are often the seat of disease, when it is judged to be
in the joint itself. But the truth is very easily known ;
for if a swelling appear under the patella, projecting
at the 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 patella, then there is reason to believe that these
belong to the great bursae, which are placed above
and below the patella, a complaint which is far less
formidable than a swelling of the joint itself: I
would almost say, easily cured; for 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 familiar or easy thing, or think that they have
done such operations safely, when probably they
were puncturing the bursas only.*
* I believe that the great bursae and the joint always commu¬
nicate largely ; and that being consequently one continuous sur¬
face, the opening of the bursae would be highly improper.—C.B.
i i °2
joints of the
These bursae mucosae lie under the tendon of the
extensor muscles, and under the ligament of the
patella: they are of the same substance with the
capsule of the joint itself; they lie over the cap¬
sule, 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 liga¬
ments, and the most perfect in all the provisions for
easy motion.
1. The great capsule of the joint encloses the
heads of the bone ; its synovial membrane secretes
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 perichon¬
drium for the cartilaginous heads of the bones,
and the covering 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 fore part,
is very thin upon its fore part, 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, the name
8
thigh, leg, and ancle.
4-8.5
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 fore part, where¬
fore it is strengthened 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
strengthening 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
°nly 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 back ligament
preventing it going too far forwards, and the fore
ligament preventing it bending too much.
5. A moving cartilage for facilitating motion
and lessening friction is not common, but is peculiar
to those joints whose motions are very frequent, or
which move under a great weight; such are the
inner head of the clavicle, the articulation of the
jaw, and the joints of the wrist and of the knee; and
it is in the knee that the moveable cartilages have
their most perfect forms and use, are large, flat, and
semilunar, to correspond with the forms on the head
of the tibia ; thicker at their outer edges, to deepen
the socket; and though moveable, yet so tied with
ligaments, as never to go out from their right place.
And, 6. The mucous folicular bundles of fat, and
the bursas mucosae, which complete the lubricating
apparatus of the joint, and the mucous frenulae or
ligaments, which both conduct the mucous fringes
and keep them in their place, are more perfect in the
i i 3
486
joints of 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.
LIST OF THE LIGAMENTS OF THE KNEE-JOINT.
External to the capsule these :
1. Ligamentum Patellae.
2. Ligamentum Laterale Internum.
3. Ligamentum Laterale Externum Longum.
4. Ligamentum Laterale Externum Breve.
5. Ligamentum Posticum Winslowii.
Within the capsule these :
6. Ligamentum Mucosum.
7. Ligamentum Alare Majus.
8. Ligamentum Alare Minus.
9. 10. Ligamenta Crucialia.
11. Ligamentum Coronarium.
12. Ligamentum Transversale.
13. 14, 15. Ligamenta Cornuum Cartilaginum Seini-
lunarium.
The most frequent accident to this joint is the
sprain of the internal lateral ligament.
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 ancle-joint. It has
no motion upon the tibia. 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 capsule : it has an anterior
and posterior accessory ligament; and is strengthened
by the external lateral ligament of the knee, which
adheres 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 fore part
of the tibia, and holds the bones together; and the
firmness of the fibula is further secured by the great
thigh, leg, and ancle.
interosseous ligament, which goes from bone to bone.
owayds the head of' the bones the interosseous liga¬
ment is deficient,
ancle.
The ancle-joint owes less of its strength to liga¬
ments 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 astragalus, with two projecting points,
the fibula forming the outer ancle, and the tibia
forming the process of the inner ancle ; 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
fore part, is named the ligamentum superius anti-
cum, consisting, in general, of one or two distinct
flat bands. Another more continued and broader
ligamentous membrane goes from the fibula to the
tibia across the back part, and is named ligamentum
posticum superius ; the ligamentum posticum infe-
rius being but a slip of the same. Next comes the
capsule 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 ancle-joint, the capsule of which is ex¬
ceedingly thin before ; but it is strengthened at the
back part, and especially at the sides, by supple¬
mentary ligaments : First, a strong ligament comes
down from the acute point of the inner ancle,
expands in a radiated form upon the geneial cap-
488
joints of the
sule ; adheres to it, and strengthens it, and is fixed
all along the side of the astragalus, to the os calcis
and naviculare. This ligament, coming from one
point, and expanding to be inserted into a long line,
has a triangular form, whence it is named ligamen-
tum 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 ancle,
tying it to the outer side of the astragalus, are indeed
distinct, one going forwards, one going backwards,
and one running directly downwards; one goes
from the point or knob of the fibula, obliquely down¬
wards and forwards to be inserted into the side of
the astragalus ; it is square and flat, of considerable
breadth and strength, and is called ligamentum
inter fibulam et astragalum anterius. Another
ligament goes perpendicularly downwards, from the
acute point of the outer ancle, to spread upon the
side of the astragalus, and of the capsule, and is
finally inserted into the heel-bone; this is named
the ligamentum inter fibulam et os calcis per-
pendiculare. A third ligament goes out still from
the same point, to go backwards over the back part
of the capsule, adheres to the back of the capsule,
and strengthens it, and is named ligamentum inter
fibulam et astragalum posterius. there is
nothing very particularly worthy of notice in the
ancle-joint, for it is covered with cartilages, lined
with a soft synovial membrane, and lubricated with
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 violence which
is required for completing this dislocation, and the
terrible complication of dislocation, fracture, and
laceration of the skin, which makes this accident so
dangerous beyond any other luxation.
thigh, leg, and ancle.
recapitulation.
From the fibula to the tarsus :
1. Ligamentum Fibula; Perpendiculare.
2. Ligamentum Fibulae Anterius.
3. Ligamentum Fibulae Posterius.
From the tibia to the tarsus :
4. Ligamentum Deltoides.
5. Ligamentum Capsulare.
Accidents to this joint are very frequent: the
sprain of the deltoid ligament is very frequent; so is
the partial laceration of the perpendicular ligament
of the fibula. We have to distinguish this last case
from the sprain of the tendons of the peronsei mus¬
cles, which is a very frequent accident.
union betwixt the bones of the tarsus.
The astragalus, os calcis, os nav1culare, aild
all the bones of the tarsus, are united to each other
by large heads, and have distinct and peculiar joints;
besides which, the bones are cross-tied to one another
by ligaments, so numerous and complicated, that
they cannot nor need not be explained. They pass
across from bone to bone, in an infinite variety of
directions, some longitudinal, some transverse, and
some oblique. There is a curious complication,
which we may call a web of ligaments, covering
the dorsum of the foot with shining and star-like
bundles; these are called ligamenta dorsalia :
each bone has its capsular ligaments for joining it
to the next; each joint of each bone has its articu¬
lating cartilages always fresh and lubricated; each
joint has, besides its capsule, flat strips of oblique,
longitudinal, and transverse ligaments, joining it to
the nearest bones. On the inside of the sole of the
foot a strong ligament of a gristly nature passes
across from the projecting point of the os calcis to
the os naviculare, and forms an elastic spring, upon
which the articulating head of the astragalus rests :
this is called ligamentum cartilagineum, the
central gristly part being the trochlea cartilaginea.
490
joines of the pelvis,
In the centre of the sole of the foot there are irre¬
gular bands, distinguished as plantare majus and
minus, planum and teres. On the outside there is
a principal ligament extending from the os calcis
to the os cuboides : this is divided into two, both of
them being called ligamentum inter os calcis et
os cuboides, but one is the long and the other the
oblique.
The metatarsal bones have their capsular ligaments
joining them to the tarsal bones; and they have
ligaments strengthening 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 metatarsal bones together, both on the upper
and on the lower surface of the foot; and all the
ligaments of the foot are of great strength and thick¬
ness. The lower ends of the metatarsal 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 ligaments, the joinings of the carpus, meta¬
carpus, 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 sup¬
porting 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 aponeu¬
rosis plantaris pedis, which is not merely an apo¬
neurosis for covering, defending, and supporting the
muscles of the foot; that might have been done on
easier terms with a fascia very slight, compared with
this j but the chief use of the plantar aponeurosis is
in supporting the arch of the foot. It passes from
point to point, like the bow-string betwixt the two
horns of a bow, and after leaping, or hard walking,
THIGH, LEG, AND ANCLE.
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 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 nar¬
row 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 aponeuroses, which cover their own particular
muscles, and are implanted into the roots of the great
toe and of the little toe.
The bursas mucosae surround the ancle and foot in
great numbers. None of them having any very direct
connection with the joint, and most of them accom¬
panying the long tendons as they pass behind the
ancle, or in the sole of the foot, are of that kind
which we call tendinous sheaths. First, there are
sheaths of two or three inches long, which surround
the tendons of the tibialis posticus, and of the pero-
nsei muscles, as they pass down behind the ancle.
The sheaths of the peronaei 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
tendons, and then a bursa peculiar to the tendons of
the peronaeus brevis muscle, and about an inch in
length. When the peronaeus longus begins to pass
under the sole of the foot, the sheath which enclosed
it behind the ancle 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 ancle, a bursa of three inches in length sur¬
rounds them, and facilitates the motion. As the ten¬
dons of the flexor muscle 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 muscle : but whenever they touch the
first joints of their toes, they once more rub against
492
joints of the pelvis, &c.
a hard bone. New bursas 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 ten¬
don 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 tendinous
sheaths ; nor betwixt the tendinous sheaths and the
capsules of joints.
Joints have been arranged under various forms, as
shown in the beginning of this chapter, but not with
much success ; and I do not know that enumerating
the joints in any particular order will either explain
the motions of individual 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 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 VERTEBRiE, the elbow, and the ancle-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 free¬
dom of a ball and socket-joint, yet with the strength
and security of the strictest hinge: thus the wrist
having one joint by which its turning motions are
performed, and another joint by which it rolls, has
the two great endowments so rarely combined in any
joint, of the freest motion, and of great strength; so
also has the head, by the combination of two joints
of opposite uses and forms; for its own condyles
play like a mere hinge upon the atlas, and the axis
of the dentata 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
of the burs^e mucosae.
obscure and shuffling motion, that it cannot be ob¬
served. 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 themselves,
but are appointed, by a diffused and gradual yielding,
to facilitate the motions of other joints.
of the burs.e mucosae.
The BURSiE MucosiE are little bags or sacs, placed
betwixt the tendons and bones, where there is much
friction. By the smoothness of their inner surfaces,
and the lubrication of their surfaces, by a fluid
similar to the synovia, they act the office of friction
wheels in machinery, and take off the too severe
pressure or friction from the bone or tendon. As
they are of a structure similar to the apparatus of
joints, they are subject to similar diseases. This
most common disease is a kind of dropsy, which
produces a puffiness or compressible swelling around
the joint. Although we have mentioned the prin¬
cipal bursse, in treating of the joints and the
muscles, yet we consider it right to enumerate them
here.
In connection with the shoulder-joint, these :
1. A very large bursa under the acromion, and
betwixt it and the head of the humerus.
2. Betwixt the head of the clavicle, and the cora-
coid process of the scapula.
3. Upon the capsule of the shoulder-joint, under
the tendon of the subscapulars muscle.
4. Under the deltoid muscle.
5. Under the tendon of the latissimus dorsi.
The principal bursae around the elbow-joint, are
these
1. Betwixt the tendon of the biceps flexor cubiti,
and the radius.
2. Over the round head of the radius, and below
the extensor muscles.
3. On the olecranon and end of the humerus,
under the triceps tendon.
494
of the bursje mucosae.
About the wrist, these :
1. A large bursa betwixt the flexor tendons, and
the carpus.
2. On the trapezium.
3. On the pisiforme.
4. On the back of the carpus, and under the ex¬
tensor carpi radialis.
5. Betwixt the ligament of the wrist, and the ten¬
don of the extensor carpi ulnaris.
Besides these sacs or proper bursas, sheaths sur¬
round the tendons of almost all the muscles about
the wrist-joint.
On the pelvis, these :
1. A large bursa betwixt the glutaeus maximus,
and the vastus externus.
2. Betwixt the capsule of the hip-joint, and the
psoas and iliacus internus.
3. Under the pectinalis.
4. A large one on the surface of the trochanter
major, under the glutseus maximus. — Also, under
the glutaeus minimus.
5. On the os ischii, under the origin of the biceps.
6. Under the tendons of the rotators of the thigh¬
bone.
In the thigh, and around the knee-joint, these :
1. Under the tendon of the quadriceps, and com¬
municating with the knee-joint.
2. Under the ligament of the patella.
3. Betwixt the insertion of the semimembranosus,
and the origin of the gastrocnemius.
4. Over the internal lateral ligament of the knee-
joint.
5. Under the popliteus.
N. B. Several irregular bursas around the tendons
inserted into the tibia and fibula.
Around the ancle-joint.
All the principal tendons which cross the ancle-
joint have bursas under or around them, as the ten¬
don of the tibialis anticus, the extensor proprius, the
extensor digitorum, the peronasus longus and brevis.
There is also a proper bursa betwixt the tendo
4
of the circulating system.
Achillis and os calcis. Another under the flexor
longus pollicis; and also under the flexor longus
digitorum, and the tibialis posticus.
Uiese bursae it is necessary for the surgeon to
know, because after sprain and injuries, effusion
takes place in them, and they present a puffy swell¬
ing over the joint, not easily understood, without the
recollection of the natural anatomy.
OF THE CIRCULATING SYSTEM.
We have already understood that a continual revo¬
lution or change of the material of the animal frame
is necessarily connected with life. The living prin¬
ciple may be joined to the animal or vegetable mat¬
ter, and remain in a latent state * ; but when its pre¬
sence is betrayed by action, it has begun a course of
existence through certain defined stages, and during
this active condition, all the material of the frame
performs a continual revolution.
While solids are necessary to the constitution of
the frame, fluids are necessary to these internal
changes. From the fluids the solids are formed, and
the solids are again broken down and change their
condition of aggregation, and become fluid; and cir¬
culate in the vessels. The fluid blood and the blood
vessels are therefore necessary to all the operations
of life, since without them the revolution of solids
into fluids, and fluids into solids, could not take
place ; the body would be stagnant and fixed, and
no better than a machine, which being broken or
wasted, possesses no power of reparation.
The Hunters began their demonstration of the
system by exhibiting the condition of the blood, and
the splendid consequences which attended this mode
should incline us to follow their example.
* Mr. Hunter, in his lecture, illustrated the condition of life in
the seed before vegetation, or in the egg before incubation, by
the discoveries of Black, of the presence of heat in bodies in an
insensible state.
OF THE BLOOD.
QUALITIES OF THE BLOOD.
Blood is a fluid of a rich and beautiful colour : it
is vermilion-coloured in the arteries, strong purple
in the veins, and black, or almost so, at the right side
of the heart, and varies somewhat in the depth of its
colour in certain parts of the body ; it feels thick
and unctuous betwixt the fingers, and is of a slightly
saline taste. The quantity of blood in the body is
estimated to be thirty pounds in a man weighing one
hundred and fifty pounds ; or one fifth of his weight;
and it is supposed that three fourths of this is in
the veins, and the remaining fourth only in the
arteries. In various individuals, but much more in
different animals, it varies with their functions and
manner of life; it is different in birds, in fishes, in
insects; it is red or pale, warm or cold, in different
classes of animals : and from this last variety comes
our division of animals into those of warm and cold
blood. When drawn from a vein, the blood spon¬
taneously coagulates in about three or four minutes,
and at this time heat is evolved and the temperature
is raised 7 or 8 degrees, and* carbonic acid gas is
evolved. *
It is by the most simple and natural methods
that we examine the blood ; since when drawn from
a vein it almost spontaneously 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 sanguineum, 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; and 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 proper fibrin. Or we may separate this
* Brande.
OF THE BLOOD.
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 fibrin
gathers upon the rods, and the serum, with the red
particles suspended in it, remains behind. The
coagulable part was called fibrin, from the fibrous
appearance it assumed in this experiment, a name it
has retained.
The red globules, as we have observed, are not
universal ; yet in all creatures, even in colourless
insects, there seem to be formal particles in the
blood.
The red globules of the human blood are easily
seen; they are best examined with a simple lens,
the globules being diluted in serum and laid upon an
inclined plane, not in water, which dissolves them
quickly, but in serum, which has the property of pre¬
serving their globular form. The watery solution of
this part of the blood turns the syrup of violets green,
and contains soda and albumen. The size of the
particles of the blood varies in various creatures : it
is asserted that, in the foetus, they are bigger than
in a grown animal; and although Leeuwenhoek
thought it essential to his doctrine to say that they
were alike in all creatures, there are, in respect to
the size of the animals, the strangest reverses. The
Skate has red globules much larger, and the Ox has
globules 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
has been estimated not to exceed the five 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,
VOL. I. K K ,
498
OF THE BLOOD.
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 dropping
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.
Falconer, with all the zeal of a friend, published
Hewson's discoveries after he was dead; lamenting, as
we all must do, the loss of a promising young man.
Falconer thoughthe sawthese globules, notas spheres,
but as flattened spheres ; he thought lie 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 con¬
jectured that these globules are compressed when
they come into narrow passages, and expand again
when they get into wider arteries. This Reichell
says he has seen, and Blumenbach believes; but
Blumenbach, less easy of belief with regard to all
these strange forms ascribed to the particles of the
blood, pronounces his dissent in plain terms. " They
appear," says he, " to my eye no other than simple
globules apparently" of mucus : that lenticular or
oval form which authors speak of, I have not seen."
The following are their chief properties with
regard to the rest of the blood. When blood stands,
the red globules fall to the bottom, because they are
heavier than the other parts of the blood ; and al¬
though the fibrin entangles them while it is forming,
still it is to be noticed that the cake is always redder
1
OP THE BLOOD.
at the bottom; and when by circumstances of con¬
stitution this coagulation is very slow, some globules
escape the grasp of the coagulum, and the serum is
tinged witn red, and the cake, though coloured at the
bottom, is white at the top, and thus the clot is said
to have the buffy coat. The globules preserve their
form only while in the blood, and seem to be sup¬
ported 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 globules are gone : when we mean to pre¬
serve their forms for experiment, we must keep them
in serum. I have looked upon the vitality of the
blood as the cause of its fluidity. It coagulates most
slowly when inflamed, which of course permits the
globules to gravitate and the buffy coat to be formed.
Its quantity, in regard to the whole mass, varies so,
that the appearance of the blood is an 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, the fibrin and red particles
may be accumulated; in hard working men they
abound; they may be accumulated by exercise into
particular parts, as in the wings of Moorfowl or
Pigeons, 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 sys¬
tem. In fishes the flesh is colourless ; in such a
system, particular glands only, or viscera, as the
liver, stomach, or spleen, are coloured with blood,
and but a small proportion circulates in the other
parts.
The redness of these particles is a peculiarity.
The chemical physiologists ascribed it to iron con¬
tained in the blood. But the present opinion is, that
there is not more iron in the ied paiticles than in the
other component parts ot the blood.
COAGULUM OR CRUOR.
The self-coagulating part of the blood, the cake
which is left when we wash away the red globules,
K K 2
500
OF THE BLOOD.
that which has been called the gluten, and now the
fibrin, is by far the most important part of the mass,
the most universally diffused in the animal system,
the most necessary for the supply and growth of
parts. It spontaneously concretes, and neither
heat nor cold, nor dilution, will prevent its coagula¬
tion. The proportion of crassamentum to serum is
564. per cent. It encreases with the vigor of the
system. Circulating in the vessels, it furnishes the
solids of the body ; when washed, it is white, insipid,
extremely tenacious, and very fibrous, and can be
drawn out; and it is the coagulation of this part
that makes the long fibrous strings which we find in
the tub when bleeding a patient in the foot in very
hot water. Being slightly dried, it shrinks into a
substance like parchment; being hardened by heat,
it becomes like a piece of horn or bone : when burnt,
it shrinks and crackles, with a very fetid smell, like
the burning of feathers, wool, flesh, or any other
animal substance ; by which we know it to be the
part of the blood which is the most perfectly ani-
malized, and the most ready to be assimilated with
the living solids. When distilled, it gives ammo-
niacal salt and alkaline water, and a very thick heavy
fetid oil, and much mephitis, which are the marks
of the most perfect animal nature ; and after burning
it, the residuum is a phosphate of lime, or in other
words, the earth of bones.
What takes place within the living and active blood
Vessels cannot be made matter of demonstration ; but
there is no reason to doubt that an important change
is wrought upon the contained fluid in the moment
of secretion, during that change, when from a fluid
it becomes a component solid of the body. We see
how the greater part of the body is composed of
fibrin, and the analysis of any single part confirms
this. A muscle being squeezed, and thoroughly
cleansed of blood, washed in spirits of wine, and
again cleansed, is seen plainly to be but a peculiar
form of coagulable lymph or fibrin. A bone being
infused in any mineral acid, oy in vinegar, its earthy
OF THE BLOOD.
501
parts are dissolved even to its centre; it becomes
soft and flexible, still retains the form of a bone ;
but what remains consists principally of coagulable
lymph. Fourcroy has said that coagulable lymph is
that part upon which nature fixes irritability, or the
contractile power ; he should have added, "but this
substance is moreover, in the animal body, the basis
of every part which possesses life." The membranes,
ligaments, tendons, periosteum, and all the white
parts of the animal body, consist chiefly of this. It
is this part, then, which is secreted by the vessels for
repairing the waste, and the accidents of the body.
THE SERUM.
The serum is the thinnest and most fluid of the
parts of the blood, into which it spontaneously sepa¬
rates. It continues oozing from the crassamentum
till the fourth day. It 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 various salts in solution, and
turns vegetable reds to green. It coagulates with a
heat much lower than that which makes it boil;
being dropped into hot water it coagulates as it falls.
But by this influence of heat the whole serum does
not coagulate, but only the albumen, a substance
like the white of an egg; what remains fluid is the
serosity. On cooling, the serosity coagulates like
size or jelly. This coagulation is owing to the
albumen dissolved in the water ; and the water being
evaporated it leaves the albumen in the form of size
or glue, or it may be precipitated from the water by
various re-agents, but especially by tanin, and by
alcohol. After the separation of' the albumen, there
remain only the salts in watery solution; these are
muriates of soda and of potash, muco-extractive
matter, subcarbonate of soda, sulphate of potash,
phosphate of soda, and phosphate ot lime.#
* The lute Dr. Marcet makes the serum give the following
products : — ivctter, 900 parts ; albumen, 86.80 ; muriate of potash
and soda, 6.60; muco-extractive matter, 4 ; subcarbonate of soda,
1.65 ; sulphate of potash, 0.35 ; earthy phosphates, 0.60.
K K 3
502
OF THE BLOOD.
We perceive that the materials, of which the body
is constructed, are contained in the blood, or formed
from that fluid. It is true that we find in the body
various substances, which do not exist formally in the
blood, but which are new compounds out of the
materials, which, by the imperfect aids of chemistry,
we discover in it.
LIFE OF THE BLOOD.
Mr. Hunter, in forming his suite of preparations
of the incubated egg, was led to reflect on the fresh¬
ness of the yolk and the white of the eggs which are
fit for incubation, while placed in circumstances
which should quickly have produced putrefaction.
What can it be, he said, which thus counteracts the
chemical decomposition and prevents putrefaction,
but the principle of life ? He was thus led to make
experiments, which ascertained that the same prin¬
ciple which in the egg prevented putrefaction,
resisted cold. Life, according to these suggestions,
was not a result of organization, but a principle
added to the material, which might be either fluid or
solid. Philosophically considered it is equally intel¬
ligible, that life shall be united to a fluid as to a
solid; but we are more familiar with the latter,
though we do not understand the mode of union
more perfectly. It will however reconcile us to the
fact to remember, that, in regard to the animal frame,
solidity and fluidity are terms referable to different
conditions of aggregation of the same substances;
all parts of the body being in that state of revolution
whilst there is life, that they are at one time fluid
and at another solid. A particular and permanent
figure of parts in the animal body, is necessary to
mechanical action^ but not required for the mere
presence of life ; though the blood may have no
motion in itself, and yet it may have the principle
of life added to it. Thus Mr. Hunter argued, and
then he said, Can we deny life to this fluid which
becomes the means of life, conveying it to the other
OF THE BLOOD.
503
parts of the body, even to the nerves themselves ? For
nerves do not convey life, but only direct the motions
of parts, and without the blood the nerves them¬
selves cease to be alive. Health, Mr. Hunter con¬
ceived, to consist in the harmony existing betwixt
the solids and fluids, and betwixt the blood and its
containing vessels, and in .disease there is also a con¬
sent betwixt them ; if solids are disordered, the
blood also puts on a diseased appearance ; if it cir¬
culates in inflamed solids, it acquires an inflammatory
disposition, and the condition is marked by signs.
I have said, " that the blood is a fluid of a rich and
beautiful colour; vermilion-coloured in the arteries,
dark 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, expires, 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 con¬
verted into the vermilion blood of the arteries, and
the change happening so plainly from access of air, is
a phenomenon of the most interesting nature, -and
binds us to look into the doctrines of chemistry for
the solution of a phenomenon to which there is in
all the animal economy nothing equal.
It is the study of air and aerial fluids that has
brought to light all the beautiful discoveries of which
modern chemistry can boast. The simplicity of the
facts in chemistry, the correctness of the reasoning,
the grandeur which now the whole science assumes,
is very pleasing; and leaves us not without hope,
that by this science, all others, and ours in an espe¬
cial manner, may be improved.
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 unvary¬
ing process over each article of the mateiia medica j
K K 4
504
OF THE BLOOD.
and among hundreds of medicinal plants which they
had thus analysed, they could find no variety of prin¬
ciples, 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 disburthened
their consciences of all they knew, pleased their
scholars, and set the physicians to work, forming
magnificent theories of salts, sulphurs, and oils ; for
such has ever been the connection of chemistry with
physiology, 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 at¬
tempted ; it was supposed that the subject of their
operation was consumed, annihilated, wasted into air,
and quite gone. When they thus stopped at airs,
they stopped where only their analysis became inte¬
resting or simple; stopping where they stopped,
among their oils and sulphurs, they made their
science a mere rhapsody 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 operations, as the
dense bodies from which they are produced : that it
is heat alone (a substance which irresistibly forces its
way into all bodies) that converts any substance into
the aerial form : that some bodies require for their
fluidity merely the heat of the atmosphere, and so
cannot appear on this planet in any solid form : that
others require some new principle to be added, in
order to give them the gaseous or aerial form : that
others require very intense heat to force them into
OF THE BLOOD.
505
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 apparent, as of
fixed air, which proceeds from charcoal; others, as
oxygen or azotic air, (the great constituents of our
atmosphere,) 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 properties, not only in a perceptible, but in
a wonderful degree; so that these abstractions and
combinations constitute some of the most general
and important facts. When the old chemists, then,
neglected to examine these airs, they refrained from
examining the first elements of bodies at the very
moment in which they came within their power.
That these must be the most material and im¬
portant facts in all the science, it is easy to explain ;
for chemistry, ever since it has been a science, has
rested upon one single point. There are certain great
operations in chemistry which we perceive to have
the strictest analogy with each other, or rather to be
the same: the operations are the combustion of in¬
flammable bodies, the respiration of animals, the cal¬
cination of metals ; and whatever theory explains one
explains the whole. The older chemists observed,
that when they burnt an inflammable body, the
surrounding air was contaminated, the substance
itself was annihilated, nothing remained of its former
existence but the foul air ; and they supposed that
this inflammable body consisted of a pure inflamma¬
ble principle, which was the substance 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
506
OF THE BLOOD.
air unfit for burning or breathing, loaded, as they
supposed, with the inflammable principle or phlogis¬
ton. When they calcined a metal, (which is done
merely by heating the metal and exposing it to air,)
they found, as in these other operations, the air con¬
taminated, the metal losing its metallic lustre, duc¬
tility, and all the marks of a metal, — acquiring (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 out of an inflam¬
mable principle to the air; and to say concerning
respiration, that it was the business of the air to take
away continually the superabundant phlogiston of
the blood j but how a metal should pass from a mild
to a most acrimonious and caustic state ; and above
all, how by the loss of its inflammable principle it
should not lose in weight, but increase in weight!
This was the Gordian knot which they had to untie,
and which they cut lustily, betaking themselves, in
defiance of all philosophy, to the absurd project of a
principle of absolute lightness. They all agreed to
call the phlogistic 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 inflam¬
mable principle upon which they all depended ; but
the weight of it was increased, 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.
OF THE BLOOD.
507
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
chemistry 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.
Upon our atmosphere and its surprising harmony
with all parts of nature ; with animal and vegetable
life ; with water, metals, acids, and all the solid
bodies into which it enters — much more depends
than it is easy to conceive. Could we have supposed
that it was the cause, not merely of life in all living
creatures, but almost the cause of all the properties
that reside in the most solid forms ? Could we have
supposed that air rendered heavy bodies heavier,
changed metals into the most caustic substances,
converted many bodies into acids, changed inflam¬
mable air into the pure element of water, which at
least we have hitherto conceived to be pure.
The atmosphere contains various gases or airs ;
but one only, viz. vital air or oxygen 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 sub¬
stantial form, but it can be combined with many
various 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, &c. seem very distinct from each
508
of the blood.
other; although combustion, calcination, and the
forming of acids, are processes seemingly very un¬
like ; 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;
and there is a certain analogy betwixt breathing and
these chemical processes, which, however, the che¬
mists have carried too far.
First, when an inflammable body is burnt, or con¬
sumed by fire, the basis of pure air is combining
with the combustible body ; the air is entering into
a new combination, and therefore must give out its
heat; it combines rapidly, gives out its heat rapidly,
is wasted; 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 which
was burnt, and of the basis of pure air. Thus, for
example^ when we burn charcoal or carbon, the
whole substance of it, weight for weight, is con¬
verted 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 ferment¬
ing 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, then, is a
process which consists in the rapid assumption of the
basis of pure air, and a consequent conversion of the
burning body into an air or gas endowed with pecu¬
liar qualities and powers.
So chemists have supposed that the function of
respiration differs from these only in the rapidity of
the process. So far it is true, that the carbon of the
blood, secreted and thrown off from the lungs, unites
to the oxygen of the atmosphere. But it is a mistake
to suppose, as they have done, that the blood be¬
comes oxydated like a metal; there is no proof that
of the blood.
509
oxygen unites to the blood. It appears only to be
the means of involving and extricating the carbon of
the blood, and converting it into carbonic acid gas.
No doubt there is a balance preserved betwixt the
function of the lungs in producing carbon and the
condition of the atmosphere to receive it; for our
atmosphere is so tempered that no more than twenty-
seven parts of a hundred consists of pare air, as we
term it, that is, of oxygen. 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 oxygen too rapidly sup¬
plied, is inflamed quickly, and dies.
As there are various marks of the influence of
oxygen on the blood, there are terrible proofs of its
importance in the system, and how miserable the
person is who has imperfect organs, or an ill oxy¬
genated blood. It signifies not to our present pur¬
pose, whether any thing is actually given to the cir¬
culating blood during respiration, or if only the
carbonaceous matter be separated and carried away ;
the contact of blood with a certain portion of pure
air or oxygen is absolutely necessary to the con¬
tinuance of life.
Nature, disregarding all occasional supplies, as by
the absorption of the skin, the assimilation of aliments,
&c. has appointed one great organ for the oxygena¬
tion of the blood, viz. the lungs. In opening the
breast of a living creature we best see the connec¬
tion of respiration with the great system ; but it is
out of the body that we can best understand its par¬
ticular 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 atmos¬
pheric air, it assumes a florid colour ; for in the
atmosphere there is a large proportion of oxygen
gas ; if, lastly, we expose it to oxygen gas, the purest
of all air, as chemists would formerly have expressed
,510
OF THE BLOOD.
themselves, it grows extremely florid: and it must
either be that the carbon in the blood is attracted,
and floated off, and united to the oxygen, or oxygen
is absorbed into the blood; and the former opinion
prevails.
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 florid;
and when the air is pressed out again, it becomes
black. If the air-pump be exhausted over a dish of
blood, the blood becomes dark in the vacuum ; and
it becomes florid when the air is allowed to rush in
again. If you expose blood in a moist bladder, the
blood is oxygenated through the walls of the bladder;
which brings this experiment as close as may be to
the phenomenon of blood oxygenated through the
cells of the air vesicles of the lungs, and through the
coats of the blood-vessels which circulate the blood
upon those air vesicles.
When we open a Frog, or Newt, or other amphi¬
bious creature, we see a long and slender artery
accompanied by a slender vein, running from top to
bottom along the whole surface of their lungs; and
while their heart continues to beat, we see this pul¬
monic artery black, the vein red, the lungs them¬
selves most delicate and pellucid, like the swimming
bladder of a fish: on the other hand, when we have
an opportunity of seeing the extremities of the
arteries and veins in the circulation through the body,
the blood of the vein is dark and that of the artery
red ; so that surgeons distinguish venous and arterial
blood 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 dark ; 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 stran¬
gulations, in hanging or drowning, in fits of passion
or of coughing, or in any accident which interrupts
OF THE BLOOD.
511
the lungs ? The face of a child during a paroxysm of
the hooping cough, is it not 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 ? The first
effect of oxygenation is a reddening of the blood.
The blood of ecchymosis, the blood of aneurismal
bags, are all black; and the blood of varices is so
very black, that the ancients said they were filled
with atrabilis or black bile. The stripes, inflicted on
a soldier as a punishment, are at first of the most
lively red, but soon become black.
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 pulsation
of the heart ceases : and, lastly, the trachea of the
Frog being untied, and the creature allowed to
breathe again, the blood becomes florid, and the
heart acts.
We have stated the facts regarding this matter,
as they have been brought forward, and as they
appear. But a closer inspection of the phenomena
will probably show that the oxygen is not in these
instances the stimulus. But that the change pro¬
duced upon the blood in respiration, makes that fluid
more capable of supplying the irritability of the mus¬
cular fibre, and, consequently, of adding power to
the heart. The load of carbon which the venous
blood carries back from the circulation of the body,
makes it incapable of adding to the irritability or
contractile power of muscles. But when by purifi¬
cation in the lungs that carbon is carried off in form
of carbonic acid gas, the colour of the blood is
restored, and with it new powers.
By these views the facts stated above have a new
light thrown on them, the heart does not become
weak, because the black blood is not stimulant, but
512 of the mechanism
because being black, and loaded with carbon, it is
incapable of supporting the irritability of the mus¬
cular fibres of the heart.
OF THE HEART, ARTERIES, AND VEINS.
OF THE HEART.
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 arteries and of veins ; — the arte¬
ries 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, ex¬
ceedingly large, pellucid almost in their coats, incap¬
able 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 deposit at the right side a quan¬
tity of blood equal to that which is at each pulsation
driven out from the left. The heart is placed betwixt
the arteries 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 con¬
traction, 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 performs in the same instant two circu¬
lations, 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
excitement of the arteries, are two chief points of
4
of the heart.
513
modern physiology, which every step of the following
demonstration will tend to explain.*
It will be most easy to conceive at first the idea of
a moi e simple heart, of one circle of actions, of one
simple circulation; of one bag for re¬
ceiving, and another joined to it for
propelling the blood. Indeed a heart
consists merely of these essential parts ;
a great vein, an auricle, a ventricle,
and a great artery : of a vein which
returns the blood from all the body ; of
an auricle or smaller bag, which receives
that blood and retains it till the action
of the heart is relaxed; of a ventricle
(which is the proper heart), strong, mus¬
cular, very irritable, and easily excited,
into which the auricle pours its blood ;
of an artery which is allied to the ven¬
tricle 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 extremities in the body, and
uniting, the whole is a circle, and the heart is the
central power.
If an animal were not to breathe, its system might
be exactly what is now described; it would have
but one vein, one auricle, one ventricle, one artery;
it would 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 suppose this blood, so essential to our existence,
to have in it some principle of life, which is con¬
tinually lost, or in its passage through the body, to
be impregnated with something which should be
* Professor Blumenbach reckons the whole mass of blood in
the body to be 33 pounds. He takes 75 as the average number
of pulsations of the heart in a minute : and he supposes the heart
expels two ounces of blood at every contraction. Proceeding
upon these data, he calculates that the whole of the blood passes
through the circulation in two minutes and a half.
vol. i. l l
514
OF THE MECHANISM
thrown off, tliat principle must be continually re¬
newed, or an opportunity given to send off what is
offensive to life : the heart which tills 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
renewed in many various ways. It might, for exam¬
ple, circulate in some peculiar viscus ; 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 imperfectly comprehend : in the chick we see its
blood circulating over the yolk, (for the yolk is in¬
closed within the membranes of the unhatched
chick,) and we perceive the blood redder as it
returns to the heart, and plainly changed : in fish
we find the blood circulated 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, essen¬
tial to life ; in those who die from bleeding, we can
perceive from the livor of the face, from the sobbing
and struggles of the chest, from the regular convul¬
sive sighs of those creatures which are butchered,
rather a desire for air than a want of blood. It is
for the purpose 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.
There are other varieties which distinguish animals
into creatures of cold or of warm blood; for there
are certain constitutions which do not require that
the blood should be thus continually renewed. It is
not because animals are amphibious, or go into the
water, that they have peculiar lungs ; for the Land
Tortoise, the Newt, the Cameleon, never go into the
water; yet they have membraneous lungs: nor indeed
can the amphibian, as the Seal, the Porpoise, the
Sea-lion, &c. dive and exist under water more than
a man can do, though for whole days they lie in
OF THE HEART.
515
herds basking upon the shore : it is their peculiar
constitution to need less than other creatures the
office of the lungs. The cold-blooded animals are
generally creeping animals, sluggish, languid, cold,
inert, difficultly moved, and tenacious of life to a
wonderful degree. They can bear all kinds of sti¬
muli ; they can bear to have their heads, legs, bowels,
cut away ; and among other peculiarities 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. By
all which it is clear that they cannot live without
breathing. That this function is necessary to their
existence : but that they are tenacious of life.
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 parti¬
tions so imperfect betwixt them that they are abso¬
lutely 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 benefit 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 reservoir for all the blood both of the body and
of the lungs; there is one neat, small, and very
powerful ventricle placed below the reservoir, having
strength quite sufficient for moving both the blood
of the lungs and the blood of the body ; and this
ventricle gives off an aorta, which soon divides into
two branches, one for the body, and one for the
lungs ; and these of course have but half the blood
of this heart exposed to the air: these also are
L L 2
516
OF THE MECHANISM
cold-blooded animals, of which take this as an
example.
But all breathing creatures, such as are called ani¬
mals of hot blood, have two hearts; the one heart is
sending blood through the lungs, while the other
heart is pushing its blood over the body; not the
half only, but the whole blood which is sent by each
stroke of the heart over the body must have first
passed through the lungs ; no blood can reach the
heart for 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
difficulties 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 re¬
course to plans, such as cannot fail to make all this
intricate mechanism be easily conceived.
The most simple form of the heart, which is repre¬
sented in the plan on page 513. has a vein marked
(a),—an auricle (b),—a ventricle (c),—an artery
(d) ;—it has no provision for purifying the blood;
it has no resemblance to that kind of heart which is
connected with lungs ; but the blood is received by
the veins, falls into the auricle, is driven by its force
7
of the heart.
into the ventricle, by the ventricle it is thrown into
the artery, and courses round all the body, till at
length, reaching the extremities 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 repre¬
sented in page 516 ; it is a frog's heart: it has the
most simple form, and the fewest parts; it has the
same vein, auricle, ventricle, and artery: but its
great artery divides into two chief branches, of which
—(d)the aorta goes to the body,—(e) the pulmonic
artery goes to each side of the iungs.
The heart of a breathing creature is represented
here in its most intelligible form; and the double
# circulation ofthe
is set off from the
on the right side
vein called vena cava from its immense size ; —
there is an ascending and a descending cava ; the
one brings the blood from the head and arms, the
other brings the blood from all the lower paits of
the body : they meet, and form by their dilatation a
chief part of that bag which is called the auricle,—
in it they deposit all the returning blood of the
body, and thus present it at the right side of the
heart to be moved through the lungs.—(4) Is the
right sinus, or right auricle ; it is in part formed
l l 3
518
of the mechanism
by a dilatation of these veins, but it puts on a strong
and muscular nature as it approaches the heart; it
is the first cavity of the heart, and, like all its parts,
is strong and irritable ; it is tilled by the returning
blood of the cavae ; it receives, dilates, is oppressed
by this great quantity of blood ; it is strongly ex¬
cited to act; in its action the blood goes down into
the ventricle or lower cavity of the heart. — (c) Is
the right ventricle, thick and strong in its walls,
and of great muscular power; it is filled by the auricle,
and is strongly stimulated both by the stroke of the
auricle, and by the weight and quantity, and also, in
some degree, by the qualities of the blood ; its ac¬
tion is sudden and violent, and it drives the blood
through all the system of the lungs. — (rf) Is the
pulmonic artery,---the artery of the lungs which
receives all the blood of the right side of the heart;
it is filled by the stroke of the right ventricle, from
whose cavity it arises; it carries the blood in many
branches through all the substance of the lungs ;
and thus that blood which had returned imperfect
and robbed of its vital quality to the right auricle of
the heart, is by this circulation through the pulmonic
artery ventilated and renewed, and made fit for the
uses of the system ; 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 a vein, an auricle, a ventricle, and
an artery j for as the right heart receives the contami¬
nated 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. The veins of the lungs
are sometimes four, sometimes five in number; they
enter from each side of the lungs, and return the blood
purified in the lungs to the left auricle of the heart. —
GO Is the left auricle, smaller, but more muscular,
of the heart.
519
and stronger than the right; it receives easily what¬
ever quantity of blood the kings convey to it; it is
irritated, contracts, forces the mouth of the ventricle,
and tills it with this purified and redder blood.—
(&0 is the left ventricle, whose form is longer, its
fleshy walls thicker, its cavity smaller, its power
greater far than that of the right side; this ventricle
is thus small that it may be easily filled and stimu¬
lated, 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, not only
delivers itself of its own blood, but propels all the
blood of the body, communicates its vibratory stroke
to the extremest vessels, and excites the whole ; this
is the greater circle or circulation of the body, as
opposed to the shorter circulation or lesser circle of
the lungs.
That there are strictly two hearts, is now clearly
made out; they are different in office ; there are two
distinct hearts, two systems of vessels, two kinds of
blood, and two circulations. These two hearts might
have done their offices, though placed in the oppo¬
site sides of the breast; it is in order to strengthen
mutually the effect of each other that they are joined;
for the fibres of the two hearts intermix ; they are both
inclosed in one membraneous capsule, viz. the peri¬
cardium ; the veins, auricles, 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.
Here I have joined the right and the 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 aoita seems to aiise
from the centre of the heart, while its lootis coveied
by the great artery of the lungs; and also that the
l l 4
of the mechanism
synchronous parts, i. e. the parts which beat time
with each other maybe correctly seen.—(1) The
cavve are receiving the blood from all parts of the
body, and in the same instant the pulmonic veins are
by its auricle,, and throws its contaminated blood into
the lungs ; and in the same moment the left ven¬
tricle 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 extremities
of the body.
Thus it is easy to perceive how the successive
actions accompany 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 con¬
tinue 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 neces¬
sity 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 ven¬
tricles plainly distinct from each other, and divided
by a great space. *
* Latro, qui pcenas scelerum luebat, quando exenteraretur a
carmfice, cor habuit singularis figure, mucrone non acuto, ut
\ the left auricle,
marked also with a
second figure, is fill¬
ing with purified
blood from the lungs.
(3) The right ven¬
tricle is stimulated
receiving blood from
the lungs. (2) The
right auricle is
gradually filling with
the contaminated
blood of the body;
of the heart.
521
of the parts of the heart.
As yet I have explained only the general plan of
the circulation, without having described those
curious parts which are within the cavities of the
heart, and which support the actions in this beautiful
harmony and perfect order, each part subordinate to
some other part, and each action succeeding some
other action with perfect correctness, often without
one unsteady motion or alarming pause, during the
course of a long irregular life.
1. The venje cav^e are two in number# ; they
are named vense cavae from their very great size;
the one brings the blood from the upper, and the
other from the lower part of the body, and they are
formed of these branches : the upper vena cava (a),
is properly termed the descending cava, because it
carries the blood of the head and arms downwards
to the heart: this great vein is properly a con-
fieri solet, sed bifido ; ut distincti ventriculi manifestius externa
facie apparuerint, dexter nempe et sinister, interjecto magno
hiatu. — Bartholini Epist. p. 170. There are examples in the
lower animals, of the hearts being actually in distinct parts of
the System.
* 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 : of which the first shows the right side of the heart,
or the heart of the lungs opened ; while the second shows only
the left heart, or the heart of the body opened.
of the mechanism
tinuation 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 (b)—by a great branch, con¬
taining the axillary and jugular veins of the left side,
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 cava ascendens, brings
in like manner all the blood from the belly and
lower parts of the body by two great branches. One,
marked (c),—is the 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 genera¬
tion, the kidneys, &c.; it is named the vena cava
abdominalis, because of its lying in the abdomen.
Others marked (b),—- arise in three or four great
branches from the liver ; they are named the branches
of the vena cava in the liver, or the ven.#: cavje
hepaticve ; and these make up the lower cava: and
the lower and the upper cavae now join themselves
at (e),—to form the right sinus of the heart (f).
2. The right sinus of the heart, marked (e), is
of considerable extent; it is just the gradual dilatation
of the two veins forming the auricle or reservoir
which is incessantly to supply the heart; the veins
grow stronger as they approach the ^inus, and the
sinus still stronger as it approaches the auricle 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 its
inner part. To say thatthese 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.
of the heart.
523
3. Ihe tuberculum Loweri should be looked for
in this point, if it were not really an imagination
merely of that celebrated 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 de¬
scending 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; and in the place appointed for finding
this tuberculum Loweri we can find nothing but on
the inside the natural angle of the two veins, and on
the outside some fat cushioned up in that angle in
the line (h). Though generally wanting, I have
found the tuberculum Loweri very distinct in the
human heart. If we must assign a use for this angle
and this inclination of the veins, it is certainly to
direct the two streams of blood which meet here
towards the opening of the ventricle.
4. The auricle is, as I have said, a small
appendix to the great bag or sinus. It is small,
semicircular, notched or scolloped, and somewhat
like a dog's ear ; whence its name. In general,
we name the whole of this bag auricle; but by this
plan the names of sinus and auricle must be easily
understood. The point chiefly to be noted is this,
that the veins, as they approach the auricle, are
thin, delicate, transparent; that where they expand
into the sinus they become fleshy, thick, and strong;
that in the auricle itself the muscular fibres are
very strong, have deep sulci like those of the
ventricle; these strong fibres are what are named
the musculi pectinati auricula. Where these
muscles run, as in cords, across the auricle, they aie
very thick and opaque ; but in the intei stice of
each stripe or muscular fibre, the auricle is trans¬
parent, like the membranes of the veins ; and when
you look on the inner surface of the auiicle, they
stand out so distinct, and get so regular, that they
524
of the mechanism
have a resemblance to the teeth of a comb ; and
thus they are named musculi pectinati.
5. The valves of the auricle are placed at the
circle (i), where the auricle enters into the ventricle,
and the valves are marked (k): and how necessary
these are for regulating the movements of the heart
will be easily understood by considering the condi¬
tions in which the auricle and ventricle act. First,
the cavse pour in a flood of blood upon the sinus
and auricle, with a continual pressure ; the moment
the auricle has contracted, it dilates, and it is full
again ; the pressure from behind excites it to act,
and while it is acting, there is no occasion for valves
to guard those veins whose blood is pressing for¬
wards continually, because they are continually full,
and have behind them the whole pressure of the cir¬
culating 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
ventricle 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. It is
called the annulus venosus,
being that tendinous ringof the
ventricle which is towards the
venous system. The opening,
osteum venosum#, is large
enough to admit two or three
fingers to pass throngh it; it is
smooth, seems tendinous, is
plainly the place of union be¬
twixt the auricle and ventricle,
which are in the foetus (in the chick for example)
* The figure represents the osteum venosum and tricusped
valve cut out. The stringy appearance is formed by the cordae
tendineae, and the pendulous portions are the columnae carneae,
which in their natural place arc connected with the substance of
the ventricle.
J{,
3btil Vol2:p:si4.
{cfirtserUviiy tfu, (Qackjia/rb of tAe,J-QcuH>— Cffu, great (bcmrrha^j ~XJum/—
. The 6najto of tJu* (eft. Clwricfo — and the emfirwrtct, <f the Pulmonary 'Veins
OF THE HEART.
525
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 ventri¬
cle by many strings,
which being, like the
valves, of a tendin¬
ous nature, are called
cord.e TENDiNEiE, or tendinous cords; and these
cords being attached to little processes projecting
from the muscular substance of the heart, these pro¬
cesses are named columnje caiine^e, or fleshy
columns. Of these tyings of the valves there are
three chief points; the whole circle seems to be
divided into three sharp-pointed valves ; they are
named valvule tricuspides, or three pointed, or
they are still sometimes 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 opening 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 (11) is, like
its auricle, larger than the same parts on the left
side ; for this auricle 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 accidents,
as labour, violent struggles, &c., which send the
526
of the mechanism
blood too quickly upon the heart; while the left
auricle and ventricle, on the other hand, can never
be overloaded, as long as the pulmonic artery pre¬
serves 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 inner surface is extremely irregular ; it puts out
from every part of its surface very strong fleshy
columns. These fleshy columns are irregular in
size, big, strong, running along the length of the
ventricle ; some cross the ventricle, so as to connect
its opposite walls together ; some have the tendons
of the valves fixed to them : all of them have perfect
contractile 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, into the form
of what are called polypi of the heart. Yet still the
walls of the right ventricle are thinner, the fleshy
columns smaller, the cavity greater, than those of
the 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 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 towards
the opening of the auricle, the surface of the ven¬
tricle is very rugged, irregular, and crossed with
columnae carneae, while a smooth and even lubricated
channel leads towards the artery.
7- The pulmonic artery arises from the right
ventricle, to carry out the blood close by the great
of the heart.
opening at which the auricle pours it in ; the artery
arises at its root in a very bulging triangular shape.
It is the valves within the mouths of the artery that
give it this very peculiar shape without; for the
bulging root is divided into three knobs, indicating
the places of the three valves, the artery dilating
behind each valve into a little bag, which, when it
is described, is called its sinus.
8. This valve of the pulmonic artery 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 number ; they are thin but strong mem¬
branes, 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 circle, 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 ol" sigmoid valves.
Now, the condition of the ventricle while it is con¬
tracting is well understood: the auricle by its action
lays down the tricuspid or auricular valve, and fills
the ventricle ; the ventricle cannot feel the stimulus
of fulness till its valves rise, and its cordae tendineae
begin to pull; and the ventricle could not be close
for acting, nor its walls perfect, it could not in short
be an entire cavity, till the tricuspid or auricular
valves were completely raised. But there is another
opening of the ventricle, 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, tlie auiicle acts, then the ven¬
tricle, then the artery ; so that the auricle and the
artery are acting in the same moment of time ; the
528
of the mechanism
artery by acting throws down its valve, and closes
that opening of the ventricle, while the auricle is
filling it with blood : and again, the moment that the
ventricle is filled, both the auricle and artery are in
a state of relaxation; the auricular valve rises so as
to close the ventricle on that side, and the arterial
valve falls down, both because the artery has ceased
acting, and because the valve is laid flat by the whole
blood of the ventricle 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 closed 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, for example,
the aorta is as plainly muscular as the heart itself j—
it is like a second heart; and in fishes the vessel re¬
turning from the gills, and often in human monsters,
the artery alone, by its own muscular power, moves
the whole circulation without 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 no¬
thing but a strong aorta to supply its place. This
stroke of the pulmonic 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 auricula, which is the
more muscular part, is larger; the pulmonic veins
come in five great trunks from the lungs, three from
the right side and two from the left; these great
veins then enter at each side of the left auricle, by
which it gets a more square form ; the whole of the
left sinus, which forms the chief bulk of this part, is
OF THE HEART.
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 plate representing the back part
of the heart*, showing, 1. How the left ventricle lies
behind ; c2. How the left auricle is turned still more
directly backwards; 3. How the pulmonic veins
enter into it in tour 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 pul¬
monic 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 vessels, and is known
always among the vessels of the heart by the carotid
and subclavian arteries which come off from its arch.
On this plan are seen—(oo) the pulmonic veins
entering from each side of the lungs—(pp) the open¬
ing of these into the auricle — (qq) the sinus formed
* Explanation of the back view of the heart, in the adjoin¬
ing plate. .
I. 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 Sub¬
clavian 7. The Cava Descendens — 8. The Cava Ascendens,
with all its branches from the Liver — 9. The great Coronary
Vein running slong the bsck of the Hccii t betwixt tliG Auricle
and Ventricle in a groove surrounded by fat.
VOL. I. M M
530
of the mechanism
in part by the dilatation of these veins, and,—(r) the
auricula or little ear, from which the whole bag is
named auricle.
10. The valves which guard the left auricle are
seen here (ss) :—Now, it is to be remembered that
the left auricle is smaller than the right; that the
circle or opening of the left auricle is of course
smaller than that of the right; that while it requires
a valve divided into three points to fill the opening
of the right auricle, a valve divided only into two
points suffices for the opening of the left auricle:
this is the reason of this slight variety of shape be¬
twixt 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 left side, from
some very slight resemblance to a mitre, is named
valvula mitralis, 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 co¬
lumns carne^e and tendinous strings to support it;
and the ventricle (tt) has the same rough irregular
surface towards the opening of the auricle ; the same
smooth gutter—(m) 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 carneve, 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 (u)—where manifestly
the general structure 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 sub-
7
of the heart.
531
stance, and is peculiarly guarded by three small hard
tubercles, which being placed one in the apex or
point of each valve, meet together when the valve is
close, and give a more perfect resistance to the
blood, and prevent the valve being forced open.
These are to be seen chiefly in the drawing, (p. 532)
and from their being of the size of sesamum seeds,
they have the name of corpora sesamoidea ; some¬
times they are named Corpuscula Aurantii.
12. Ihe 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 curvature at the
arch of the aorta is called its great sinus, and these
three smaller bags are called the three lesser sinuses
of the aorta.
.of the coronary vessels.
But there still remains to be explained that pecu¬
liar circulation by which the heart itself is nourished ;
and yet there is nothing in it very different from the
usual form of arteries and veins : it is a part of the
general circulation of the body; for the heart is
nourished by the two first
branches which the aorta
gives off. The circulation
destined for the nourish¬
ment of the heart is pe¬
culiar in this chiefly, that
the forms of the arteries
and veins of the heart
are beautiful, and that
the arteries rise just under the valves of the aorta,
while the veins end with one great mouth in the
right auricle. The coronary arteries are two in
number, of the size of crow-quills; we see from the
inside of the artery their mouths opening above the
sigmoid valves. One artery comes from the lower
side of the aorta; it lies towards the right; it be¬
longs chiefly to the right ventricle; it comes out
mm 2
532
of the mechanism
first betwixt the roots of the aorta and pulmonic ar¬
teries ; it passes in the furrow betwixt the right ven¬
tricle and auricle, and turning round arrives at the
back part of the heart, and runs down along the
middle of that flat surface which lies upon the
diaphragm ; and when it arrives at the apex of the
heart, its extreme arteries turn round the point and
inosculate with the opposite coronary. The other
coronary belongs in like manner to the left side of
the heart, and arises from the upper side of the
aorta ; it first goes out betwixt the pulmonic artery
and the left auricle, and then turning downwards
upon the heart, it runs along that groove which is
betwixt the ventricles, and marks the place of the
partition or septum ventriculorum ; its chief branches
turn towards the left ventricle, and branch out upon
it; it belongs as peculiarly to the left side of the
heart as the other does to the right side: after sup¬
plying 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 great arteries,
constituting the vasa vasorum, as such minute
branches sent to vessels are called.*
* This is the aorta inverted, so as to show the semilunar
valves.— (a) One of the valves — (b) Corpus sesamoideum—
(c) Opening of the coronary artery.
a
of the heart.
533
^Jje great coronary vein which collects the
blood of these arteries, arises in small branches all
over the heart; these meet so as to form a trunk
upon the fore part of the heart, where the septum
or union of the ventricles is. While small, the veins
accompany their respective arteries; but after the
great trunk is formed, the vein takes its own peculiar
route. When the trunk of the great coronary vein
(accompanied by several lesser veins) arrives at the
auricle, it runs in between the left auricle and left
ventricle; it turns all round the back of the auricle
till it gets to the right side of the heart; it lies in
the deep groove betwixt the auricle and ventricle,
surrounded with much fat; and having almost en¬
tirely encircled the heart, it discharges its blood into
the right auricle, close by the entrance of the lower
cava. The opening 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 auri¬
cle, the vena innominata, &c. are all but branches of
the great coronary vein running along the right side
or lower surface of the heart; if there were to be
any marked distinction, it should be into the great
coronary vein belonging to the left side of the
heart, and the vena innominata belonging to the
right side. But one thing more is to be observed,
viz. that upon the inner surface of the right auricle
may be seen many small oblique and very curious
openings, which serve for the mouths of veins, while
their obliquity performs the office of a valve. This
name of coronary vessels is a very favourite one with
anatomists, and is applied wherever vessels surround
the parts which they belong to, however little this
encircling may be like a crown ^ and it is thus that
we have the coronary arteries of the stomach, coio-
nary arteries of the lips, and coronary aiteiies of the
heart But these vessels of the heart are really very
beautiful, and have some things very peculiar m
m m 3
534
OF THE MECHANISM
their circulation : first, with regard to the coronary
arteries, they lie with their mouths under the sig¬
moid 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 other
arteries, by the stroke of the heart, or whether they
be covered by the valve so as to let the blood rush
pass them during the action of the heart.
We see the opening of the coronary arteries*
rather, as I imagine, under the valve; though
Haller says they are above the valve, and that the
highest point to which the margin of the valve
reaches in very old men is below the opening of the
coronary artery, and half way betwixt it and the
bottom of the sinus or little bag behind the valve.
But let this be as it may, if the condition of the aorta
be considered, it will be found to make no difference ;
for though the valves rise and fall, are at one time
fully opened, and at another time closely shut, still
in both these conditions of the valve the aorta is as
full as it can hold; its contraction instantaneously
follows that of the heart, but its contraction is not,
like that of the heart, such as to bring its sides to-
Sketch of the arch of the aorta with the coronary arteries.
OF THE HEART.
535
g iei • on the contrary, the aorta is full when the
eai stukes, the action of the heart distends it to
t e greatest degree, the aorta re-acts so as to free
1 sen or this distension, but still it remains in some
degree full of blood; else how could this, like every
°. J#arter^' Preserve always its form and apparent
In this condition of matters, it is obvious that
the coronary branches are on the same footing with
all the other branches of the aortic system; that,
like all the other arteries, they first feel the stimulus
of fulness from the push of the heart, and along with
it the stroke of the aorta.
Secondly, with regard to the coronary veins a
dispute has arisen more violent than this: for it has
been doubted whether the coronary veins, large as
they are, do actually convey the whole of the blood
which the coronary arteries give out. Vieussens
believed that some of the coronary arteries opened
directly into the cavities of the heart, without the
interposition of veins. Thebesius, after him, believed
that there were some shorter ways by which the
blood was returned; not by a long circle into the
right auricle, but directly into the ventricles of the
heart. Vieussens, Thebesius, and others who be¬
longed to their party, pretended to prove this fact
by injections : but what doctrine is there which such
clumsy anatomy and awkward injections may not be
made to prove ? They used mercury, tepid water,
and air ; and they forced these, the most penetrating
* In this cut the aorta is opened at its origin,-and the semi¬
lunar valves exhibited. The openings of the coronary arteries
are seen above the margins ot the \alves.
M INI 4
OF THE MECHANISM
of all injections, till they exuded upon the inner sur¬
face 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 in¬
jections exuding from every surface ; of the pleura
and lungs; of the peritonaeum and intestines; of
the brain and dura mater ; of the mouth and tongue ;
and universally through the cellular membrane of the
whole body; but if any coarse injection, as tallow
or wax, be used, following this natural course, it
keeps within the arteries and veins, and if thin and
well prepared, finds its way back to the auricle of the
heart; but this injection also is extravasated, and is
found in the cavities of the heart.
Du Verney was so far engaged in this question,
that having an opportunity of dissecting the heart
of an elephant, he tied up the coronary arteries and
veins, washed and cleaned very thoroughly the ca¬
vities 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.
On the present occasion, a theoretical answer hap¬
pens to be as satisfactory as the most correct expe¬
riments : and it is this. If there really were to be
formed (by disease, for example,) those numerous
openings which Thebesius and Vieussens describe,
then the blood flowing all by these shorter and easier
passages, none could come to the great coronary
vein; its office would be annihilated; and itself!,
contracting gradually, would soon cease to exist.
OF THE EUSTACHIAN VALVE.
There remains to be explained in the mechanism
of the heart one point; and which I have separated
from the others; not because it is the least important,
but because it is the most difficult, and, if I may be
allowed to say so, not yet thoroughly understood:
8
of the heart.
,mtan ^le anatomy °f the Eustachian valve ;
which, if it had been easily described, should have
been hi st described; for it is a valve which lies in
the mouth of the lower cava, just where that vein
enteis the right auricle of the heart. How imperfect
a valve this is, how difficult to dissect or to 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 after fairly directed to it by
finding it in the tables of Eustachius, which were
then first found and published by Lancisi, after the
author had been dead 150 years; and yet with all
this assistance Winslow sought for it continually in
vain, till at last he reflected, that by cutting the
heart in its fore part, 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 demonstrated it to the Academy of Sciences in
France; and having just received from Lancisi his
edition of the Eustachian Table, so long hidden, and
since so outrageously praised, he called it valvula
Eustachiana, a name which it has retained to this
day, and he added reticularis, to express its lace¬
like netted appearance at its upper edge. From Win-
slow'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 office of a
valve. The very first appearance of the valve, and
its place just over the mouth of the cava, seem to
point out that use which Lancisi has assigned it, viz.
to support the blood of the upper cava, and pi event
that column of blood which descends from the cava
gravitating upon the opposite column which comes
of the mechanism
from the liver and lower parts of the body ; and yet
this, most likely, is not its use. The valve some¬
what resembles a crescent, or the membrane called
hymen. It occupies just that half of the cava which
is nearest the auricle. Its deepest part hangs over
the mouth of the cava, and is nearly half an inch in
breadth, seldom more, often less, sometimes a mere
line. Its two horns extend up along the sides of the
auricle; the posterior horn arises from the left of
the isthmus, as it is called, or edge of the oval hole ;
its anterior horn arises from the vena cava, where it
joins the auricle. Behind the valve the remains of
the foramen ovale may be seen, now shut by its thin
membrane, but still very easily distinguished ; for its
arch-like edges are so thick, strong, and muscular,
that they look like two pillars, and thence are called
the columnie foraminis ovalis. These two pillars
were called isthmus Vieussenii, and by Haller are
named annulus fossae ovalis ; while the remains of
the hole itself is so deep that it is named the fossa
ovalis. Before the Eustachian valve lies the great
opening into the ventricle ; but 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, sometimes
reticular, the one end of which connects itself with
the fore part of the Eustachian valve ; so that both
valves are moved and made tense at once.
OF THE HEART.
539
The Eustachian valve is in general thin and trans¬
parent ; it is sometimes reticulated or net-like even
in the foetus, but by no means so often as to vindi¬
cate Winslow, in adding reticularis to the name ; it
grows reticulated chiefly in the adult. The only
beautiful drawing that we have of a reticular Eus¬
tachian 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 reticulated, just
as all the 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 represents,—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 wood-cut represents the right auricle, opened to show
the Eustachian valve, foramen ovale, and the mouth of the coro¬
nary vein.
540
OF THE MECHANISM
This is the simple description of a valve, which
has been the occasion of more controversy than the
circulation of the foetus and the use of the oval hole.
Winslow first began about eighty years ago to
observe the connections and uses of this valve: he
laid it down as an absolute fact, that this valve was
almost peculiar to the foetus ; that it was perfect
only while the foramen ovale was open; that it
vanished gradually as the foramen ovale closed ; that
in the adult it was seldom seen, unless the foramen
ovale was also open by chance. It is incredible
what numbers of anatomists followed this opinion; for
the difficulty of dissecting the valve made it always
easier to say that it was only in the foetus that it
could be found: it is also incredible what absurd con¬
sequences arose from this doctrine, which, after all,
is but a dream ; for in fact the valve is more easily
shown in the adult heart.*
The foundation being now laid for connecting this
valve with the peculiar circulation of the foetus, they
conceived the following 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
* One author, I find in the Acta Vindobonensia, is exceed¬
ingly angry indeed with all the great anatomists, for not con¬
necting more strictly with each other the anatomy and accidents
of the foramen ovale and Eustachian valve; with Morgagni,
Albinus, and Wietbrecht, he is offended for saying that they had
seen the foramen ovale open, without saying one word con¬
cerning 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
enquiring into the condition of the oval 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, without
observing it open, if it was so ; especially as the oval hole being
open is by no means an usual occurrence.
OF THE HEART.
541
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 Eustachian valve into the oval hole, through
that into the left auricle and ventricle, and from
these directly into the aorta and carotids; while the
foul blood of the upper cava went down into the
right auricle and ventricle, and from that into the
ductus arteriosus, and so away down to the lower
and less noble parts of the body, and to the umbili¬
cal arteries, and so out of the system ; for the ductus
arteriosus, which comes from the right ventricle in
the foetus, joins the aorta only as it goes down the
back, and none of its blood can pass upwards into
the head.
This is the theory which, modified in various ways,
has amused the French Academy, or, rather, been
the cause of a perpetual civil war in it, for a hundred
years. This doctrine began with Winslow; it is still
acknowledged by Sabatier; and Haller, after an¬
nouncing a theory not at all differing from this, chal¬
lenges it as his own theory ; " hanc meam conjec-
turam etiam a Nichols video proponi." Of the truth
of this theory Haller was so entirely satisfied, that
he not only published it as peculiarly his own, but
reclaimed it when he thought it in danger of being
thus appropriated by another. Sabatier is the last
in this train of authors ; and in order that there
might remain no ambiguity in what they had said or
meant, he pronounces plainly that the Eustachian
valve is useful only in the foetus, and that there are
two opposite currents in the right auricle of the
heart; that the one goes from the lower cava upwards
to the foramen ovale, while the other from the upper
cava descends right into the opening of the ventricle.
What shall we say to anatomists who in the narrow
circle of the auricle conceive two currents to cross
each other directly, and to keep as clear of each
other as the arrows by which such currents are
usually represented? This error in reasoning is
below all criticism j it carries us backwards a hun-
542
OF THE MECHANISM
dred years in anatomy and in physics ; and yet this
is all that Winslow, Haller, Sabatier, and many
others, have been able to say in proof of the connec¬
tion of the Eustachian valve with the circulation of
the foetus.
Lancisi, again, believed that it was chiefly useful
by supporting 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 the
office of the valve, and which should have been re¬
garded, especially by those who said it was useful
chiefly before birth ; they have forgotten a little cir¬
cumstance, which John Hunter also forgot, when
theorising 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 foetus ; that it has no
connection with the oval hole ; that the valve is often
particularly large after the foramen ovale is closed ;
that the valve is often obliterated where yet the fora¬
men 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 relates to the auricle itself, and,
therefore, it is found in all the stages of life, smaller
or larger, according to the size or form of the heart.
The auricle on the side towards the venae cavag is
imperfect; the anterior part of the auricle chiefly
is muscular, and when it contracts, the laxity of the
* I have left these opinions as originally expressed by-
Mr. John Bell, because I think it right that the reader should
have the opinions fairly before him. In what follows he gives
his own opinion of the function of this membrane. Notwith¬
standing all that is here delivered, I believe that the principal use
of this membrane is to direct the blood during the foetal cir¬
culation, and that it remains as a mere ligamentous bond, strength¬
ening the auricle in the adult. C.B.
of the heart.
543
cava? and the great width of the sinus venosus, i. e.
oi 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 obliquely, that the side of the cava makes a
sort of wall for the auricle on that side. This wall
has entirely and distinctly the reticulated structure
of the auricle itself, with fleshy bands of muscular
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 auricle :
and that this part of the wall of the auricle should
be occasionally a little higher or lower, looser or
tenser, we need not be surprised. This further may
be observed, that wherever, as in a child, this valve
is very thin and delicate, the anterior part of the
fossa ovalis goes round that side of the auricle par¬
ticularly deep and strong. Let it also be remem¬
bered, that in certain animals this valve is particu¬
larly large and strong; now, in a creature which
goes chiefly in a horizontal posture, it may streng¬
then 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 horizontally, and there is no
such weight. The Parisian academicians describe
the heart of the Castor in the following terms:
" Under 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 dis¬
posed 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."
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
544.
OF THE ACTION
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 sub¬
stance is so dense and strong. In the heart there
can be no direct or straight fibres; for let them go
off from the basis of the heart in what direction they
may, still, as they belong to the one or the other
ventricle, they must, by following the course and
shape of that ventricle, form an oblique line. Vesa-
lius has, indeed, not represented them so: he has
drawn straight fibres only; because in the latter 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 sep¬
tum 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 transversely,
uniting the oblique fibres ; but when we go down
into the thick substance of the heart, we find its
fibres all mixed, crossed, and reticulated in a most
surprising manner; so that we at once perceive, both
that it is the strongest muscle in the body, and that
the attempt to extricate its fibres is quite absurd.*
Their desire of giving more correct and regular de¬
scriptions 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, Albinus, and Haller,
* Thickening the walls of the heart by vinegar, strong acids,
alum, or boiling the hearty have assisted us in unravelling its
structure but very little.
OF THE HEARTj
545
that the thing could not be done ; while those,
again, who pretended to particular accuracy, and
who ha\e diawn the fibres of the heart, have repre¬
sented to us such- extravagant, gross, and prepos-
teious things, as have satisfied us more than their
most ingenuous acknowledgments could have done,
that they also could accomplish nothing.
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 pro¬
perty 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 contracts.
In the very first days in which the heart appears
in the chick, while yet its parts are not distinguished,
and the punctum saliens is the only name we can
give it, the heart, even in this state, feels the slight¬
est 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 per¬
turbed 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 power 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 j heat,
caustics, sharp points, excite it to move again.
We know also another thing very peculiar con¬
cerning the irritability of this organ, viz. that it is
more irritable on its internal than on its external
surface ; for if instead of cutting out the heart we
546
OF THE ACTION
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 after the death of the body before the heart be
dead ; and just as in this peculiar part of the system
irritability is in high proportion, there are in the
scale of existence certain animals endowed in a won¬
derful 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 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 obedient to
stimuli for a still longer time. It seems as if nothing
but the loss of organization could make this irritable
muscle cease to act; or rather it seems as if even
some degree of deranged organization could be re¬
stored : 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 plumpness and contractility were restored.
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
interruption seemed to them the most inexplicable
13
OF THE HEART.
54-7
tiling in nature. Hippocrates ascribed it to the innate
^ n rS irlithe Sylvius said, that the old
anu alkaline blood in the heart mixing with the new
and acid chyle, and with the pancreatic lymph, pro¬
duced a ferment there; Swammerdam, Pitcairn, and
Fiiend, thought that the heart, and every muscle
which had no antagonist muscle, was moved by a
less piopoition 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; and that this alternate
compression and relief of the nerve was the cause of
the alternate movements of the heart. Another phy¬
sician 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 philo¬
sophy of the human body, refined upon this theory
most elegantly ; for observing that the nerves of the
heart turned round the aorta, and passed down be¬
twixt it and the pulmonic artery, he explained 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."
Descartes, who studied every thing like a right
philosopher of the old breed, viz. by conjecture
alone, supposed that a small quantity of blood re¬
mained in the ventricle after each stroke of the
heart; which drop of blood fermented, became a
sort of leaven, and operated upon the next blood
that came into the heart, " like vitriol upon tartar;
so that every successive drop of blood which fell into
the ventricle swelled and puffed up so suddenly as to
distend the heart, and then burst out by the aorta.
Philosophers have been 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 Buff'on it is all the same, great
ignorance and great presumption. But on this sub-
N N 2
54&
OF THE ACTION
ject of the pulse of the heart, physicians almost sur¬
passed the philosophers in the absurdity of their
theories, till at last they were reduced to the sad
dilemma of either giving up speaking upon this
favourite subject, or of contenting themselves with
saying, " that the heart beat by its facultas pulsifica,
its pulsative faculty."
The ancients, 1 have said, often opened living
creatures, and saw the heart struggling to relieve
itself because it was oppressed 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 blad¬
der, 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 roused again: so natural is both the incessant
action and regular alternation of contraction and re¬
laxation in the heart.
It is when we are so cruel as to open a living crea¬
ture 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 vense 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 con¬
tracting incessantly and strongly, and will continue
this struggle long after the other parts have lost their
powers. One author, whether from his awkwardness,
or the delicacy of the subject, or really from the
strength of the ventricle, assures us, that often while
he has held the aorta of a frog close with pincers, it
has burst by the mere force of the heart. If) after
violent struggles of this kind, you cut the aorta, even
of so small a creature as an eel, it will throw its
blood to the distance of three or four inches.
Ihus we not only know that we can excite the
OF THE HEART.
M 9
leai y accumulating blood in it, but that by con¬
fining the blood in it we can carry that excitement to
a \eiy high degree. But to understand what authors
have greatly puzzled themselves about, we must re¬
member that the blood performs a double office. It is,
as aiteiial blood in the coronary circulation, the
soui ce of the heart s irritability; whilst, as dilating the
cavities, it is the excitement to that irritability.
There is another circumstance of some moment in
comprehending this. The irritability of the heart is
not like that in a common voluntary muscle; every
muscle has its law of action ; and although the heart
appears to be, and indeed is, regulated in the velocity
of its action by the rapidity of its supply with blood,
yet if torn out of the body it will continue pulsating,
and the alternate action of auricle and ventricle may
be seen although there be no blood to propel. This
points out the admirable manner in which the vital
property is accommodated to the particular function,
—how the mechanical and vital provisions are made
to correspond.
With all this we can readily understand that the
dilatation by the blood is the proper stimulus to the
heart's action, and that distention is a more powerful
cause of action than pricking it. Stimuli applied
outwardly make it contract partially; it trembles in
particular fibres : but it is only letting in the blood,
or blowing it up with air, that can bring it into full
action again. When we look with cruel deliberation
upon the strokes of the heart in any living creature,
we observe that at first, during the full and rapid
action of the heart, there is hardly any perceptible in¬
terval 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 conti action
of each part is what we cannot observe, they are so
quick ; but these things we distinctly observe — the
auricle contracts and dilates the ventricle ; the ven¬
tricle contracts, subsides, and fills the aoita; the
svprta turns and twists with the force of the blood
n N 3
550
OF THE ACTION
driven into it, and by its re-action ; and the ventricle,
every time that it contracts, 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 con¬
traction 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
perpetually 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 human heart the posture is so dis¬
torted, 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
assigned; it is not in order that by being in the
* We find this explanation of the beating of the heart against
the ribs by Dr. William Hunter. " The systole and diastole of
the heart, simply, could not produce such an effect; nor could it
have been produced, if it had thrown the blood into a straight
tube, in the direction of the axis of the left ventricle, as is the
case with fish and some other classes of animals; but by throwing
the blood into a curved tube, viz. the aorta, that artery, at its
curve, endeavours to throw itself into a straight line, to increase
its capacity; but the aorta being the fixed point against the back,
and the heart in some degree loose and pendulous, the influence
of its own action is thrown upon itself, and it is tilted forwards
against the inside of the chest." — See note to John Hunter's
Treatise on the Blood, p. 146.
It must be remembered, that the right ventricle throws its blood
into the pulmonary artery at the same instant that the left propels
its blood into the aorta, and the tendency to tilt up the apex of
the heart must, therefore, belong to both arteries. The blood is
also accumulating in both the auricles at the moment the arteries
are thus filled, which is an additional cause of the point of the
heart rising.
of the heart.
551
centre it may feel less the difficulty of driving the
blood to any particular limb or part of the body ; it
is the place oi the lungs that regulates 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 : they are filled only
by the working of the bag attached to the lower jaw,
the lungs in them being 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 under the jaws, and the heart is
placed betwixt them. In insects, as in the common
Caterpillar, (the aurelia of our common Butterfly,)
the air enters by many pores on its sides; and ac¬
cordingly 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, de¬
noting 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 membrane named the mediastinum. This mem-
n n 4
552
OF THE ACTION
brane passes directly across the breast from the
sternum before till it fixes 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 surface (c), or what we usually call the
fore part of the heart, is remarkably round. The
whole heart lies out flat upon the diaphragm ; its
basis, where the auricles are, is turned towards
the spine and towards the right side ; the apex (d),
or acute point, is turned forwards and a little ob¬
liquely 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 perpendicular direction in
which hitherto, for the sake of distinctness, I have
represented it in these plans ; but the aorta goes out
from its ventricle towards the right side of the tho¬
rax ; it then turns in form of an arch, not directly
upwards, but rather backwards, towards the spine;
then it makes a third twist to turn downwards;
where it turns downwards it hooks round the pul¬
monic artery (g), just as we hook the fore fingers of
our two hands within one another; and from the
bifurcation of the pulmonic artery there goes off a
ligament to the aorta, which is the remains of the
ductus arteriosus, to be afterwards described. The
right heart (li) 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 pul-
* 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 cava:.
OF THE HEART
553
monic artery (g) covers the root of the aorta; the
left ventricle (z), from which the aorta rises, shows
little more than its point at the apex of the heart;
the left amicle (7t) is seen only in its very tip or ex-
tiemity, where it lies just behind the pulmonic
artery ; and the aorta (y ) arises from the very centre
of the heart. From this view any man may under¬
stand these vessels by other marks than the mere
colours of an injection \ and he will also easily un¬
derstand why the heart twists so in its actions, and
how it comes to pass that its posture is difficult for
us to conceive, no one part having that relation to
any other part which we should beforehand suppose.
But the pericardium, purse, or capsule, in which
the heart is contained, affects and regulates its pos¬
ture, and makes the last important point concerning
the anatomy of the heart. It is a bag of consider-
* Plan of the pericardium. — («) Outside of the pericar¬
dium — (b) part where the membrane is reflected on the heart
— (c) the same membrane covering the substance of the ven¬
tricle. N. B. _ The membrane, which is extremely thin, is repre¬
sented thick and coarse, for the sake ot illustration.
OF THE PERICARDIUM.*
554
OF THE PERICARDIUM.
able 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
relaxed ; but I believe it to surround the heart so
closely as to support it in its palpitations, and more
violent and irregular actions ; for when we inject
the heart, its pericardium remaining entire, that bag
is filled so full that we can hardly lay it open with a
probe and lancet without wounding the heart; and
still further, when we open the pericardium before
we inject 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 me¬
diastinum, of the cellular substance; it is rough
and irregular without, and fleecy, with the threads of
cellular substance, by which it is connected with all
the surrounding parts; within it is smooth, white,
tendinous, and glistening, and exceedingly strong.
As the heart lies upon the floor of the diaphragm, the
pericardium, which lies under the heart, is connected
with the diaphragm a little to the left of its tendinous
centre, and so very strongly that they are absolutely
inseparable. The pericardium surrounds the whole
heart, but it is loose everywhere except at the base
of the heart, where it is connected with the great
vessels : for the pericardium 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 outward
coat, and surrounds each vessel with a sort of ring.
For, 1st, It surrounds the pulmonic veins where they
are entering the heart; there the pericardium is
short: 2dly, It mounts higher upon the vena cava
than upon any other vessel: the cava of course is
longer within the pericardium, and it also is sur¬
rounded with a sort of ring: 3dly, It then passes
round the aorta and pulmonic artery, surrounding
these in one greater loop : 4thly, The cava inferior
is the vessel which is the shortest within the pericar¬
dium ; for the heart inclines towards the horizontal
of the pericardium.
direction ; it lies in a manner flat upon the upper
surface of the diaphragm, while the lower surface of
the diaphragm adheres to the upper surface of the
live1, i hus it happens that the liver and the right
auricle of the heart are almost in contact, the dia¬
phragm only intervening; thence the lower cava
which passes from the liver into the right auricle of
the heart cannot have any length. While the peri¬
cardium thus passes round the great vessels, it must
leave tucks and corners ; and these have been named
the cornua, or horns of the pericardium.
But there is another peculiarity in the form of the
pericardium, 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 pericardum at («<z), where
the pericardium is loose ; at ([bb), the angle where
it is reflected; and at (<x), 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 gathered 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 : its uses are to keep the heart easy and lubri¬
cated by that exhalation which proceeds from its
exhalent arteries (and which can be imitated so easily
by injecting tepid water into its aiteiies) j to suspend
* See p. 553.
556
of the pericardium.
the heart in some degree by its connections with
other parts, especially by its connections with the
mediastinum and diaphragm. The pericardium limits
the distention of the heart, and checks its too violent
actions; 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 acci¬
dents, 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, receiving the blood which came from
the rupture, has dilated in such a manner as to
receive a large quantity 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.
But while, according to authors, we have been fol¬
lowing the inflection of the pericardium, we should
not omit noticing that the membrane is double, and
that, while the finer layer of the membrane is reflected
over the heart, a stronger texture of fibres is sent off
into the sheaths of the great vessels which ascend
from the heart.
If I have not mentioned any fluid under the direct
name of aqua pericardii, or the water of the peri¬
cardium, 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 occu¬
pied the attention of the older authors in a most
ludicrous degree. Hippocrates believed that this
water of the pericardium came chiefly from the drink
we swallow, which found some way or other (as it
passed by the pericardium) to insinuate 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 concoc-
1
OF THE PERICARDIUM.
557
ion. The same men, " viri graves et docti*," declare
o us t lat the uses of the aqua pericardii are to cool
the heai t, 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 swim¬
ming in it seem lighter. By this it is pretty obvious
what absuid notions they had of the quantity of
water that may be found in the pericardium. But of
all the outrages against common sense and common
decorum, the most singular was the dispute main¬
tained among them, whether it was or was not the
water of the pericardium which rushed out when
our Saviour's side was pierced with a spear ? The
celebrated Bardius, in a learned letter to Bartholine,
shows how it was the water of the pericardium that
flowed out; but Bartholine, in his replication there¬
unto, demonstrates, that it must have been the water
of the pleura alone. This abominable and ludicrous
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. The whole truth con¬
cerning water in the pericardium is, that you find
water there whenever at any time you find it in any
of the other cavities of the body. If a person have
laboured under a continued weakness, or have been
long diseased ; if a person have lain long on his
death-bed, then you find water in the pericardium.
But if you open any living animal, as a dog, or if you
open the body of a suicide, not a drop of water will
be found in the pericardium. When such fluid is
to be found, it is of the same nature with the drop¬
sical fluids of other cavities : in the child, and in
young people, it is reddish, especially if the peii-
* They are thus denominated in all the charters of the Col¬
lege of Physicians from the time of Henry VIII. downwards.
558
OF THE PERICARDIUM.
cardium 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 re¬
sembles the liquor of a joint.
Thus does the pericardium contribute in some de¬
gree to settle 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 vessels as they run up to¬
wards the neck, or are connected with the spine;
but how slight this hold is, how much the heart must
be moved, and these vessels endangered, by shocks
and falls, it is awful to think. The pericardium is no
doubt some restraint; its connections with the dia¬
phragm and with the mediastinum make it a pro¬
vision, 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
rolls about in the thorax ; we turn to our left side
in bed, and it beats there ; we turn over to our right
side, and the heart falls back into the chest, so that
its pulse is no where to be perceived ; we incline to
our left side again, and it beats quick and strong.
The heart is raised by a full stomach, and is pushed
upwards in dropsy : and during pregnancy its pos¬
ture 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, laugh¬
ing, sneezing, and every violent effort of the thorax.
By matter collected within the thorax it may be dis¬
placed to any degree. Dr. Farquharson cured a fine
boy, about eight years old, of a great collection of
matter in the chest, whose heart was so displaced by
a vast quantity (no less than four pounds) of pus,
that it beat strongly on the right side of the breast
while his disease continued, and as soon as the pus
was evacuated, the beating of the heart returned na¬
turally 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
OF THE PERICARDIUM.
559
ric which boys have of going upon their hands with
t leu head to the ground, began to feel terrible pal¬
pitations in the left breast; these gradually increased
till he tell 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 aneu¬
risms of the ham, or that every chimney-sweeper has
not a cancer of the scrotum.
We may now close this account of the mechanism
of the heart; in which all the parts have been suc¬
cessively explained. We know how the heart is sus¬
pended by the mediastinum, and by its great vessels ;
how it is lubricated, supported, and regulated in its
motions, by the pericardium: its nerves, which re¬
main to be explained at a fitter time, are extremely
small; while its vis insita, or irritability, is great be¬
yond 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 auricle, 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 sup¬
plies the body ; and there begins a new circulation,
called the greater circulation, viz. of the body, as the
other is called the lesser circulation of the lungs.
Thus we recognise distinctly the functions of the
double heart, with all its mechanism; the stronger
heart to serve the body, the weaker heart to serve the
lungs y and we see in the plainest manner two distinct
functions performed by one compound heart: the
rio-ht heart circulates the blood in the lungs, whei e it
is'purified and renewed ; the left delivers out a quan¬
tity of blood, not such as to fill all the vessels, nor
such as to move onwards by this single stroke of the
560
OF THE HEART.
heart to the very extremities of the body, but such
merely as to give a sense of fulness and tension to the
vessels : the force is merely such as to excite and
support that action which the arteries everywhere
perform in the various organs of the body, each artery
for its appropriated purposes, and each in its pecu¬
liar 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 understand why Galen
called the right auricle the " ultimum moriens," or
the part which died last; for, upon opening the body
soon after death, he found the right auricle filled
with blood, and still palpitating with the remains of
life, when all the other parts seemed absolutely dead ;
and if the blood always accumulates on the right
side of the heart before death, it is plain that the
stimulus of that blood will preserve the remains of
life in the right side, after all appearance of life on
the left side is gone. But the cause of this accumula¬
tion of blood in the right side is very ill explained
by Haller, though it seems to have employed his
thoughts during half his life. He says, that in our
last moments we breathe with difficulty; the lungs
at last collapse, and cease to act; and when they
are collapsed, 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 pro¬
pose 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 be¬
hind 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 ;
of the heart.
the left auricle remains empty, while the blood oozes
in o ie l ight auricle from all the extremities of the
body till it fills it up.
Nothing is more agreeable than to find such phe¬
nomena described faithfully long before the reason
or them is understood. In the Parisian Dissections I
find the following description : « When the breast of
a living Dog is opened by taking away the sternum,
with the caitilaginous appendices of the ribs, the
lungs are observed suddenly to sink, and afterwards
the circulation of the blood and the motion of the
heart to cease. In a little time after the right ven¬
tricle of the heart and the vena cava are swelled, as
if they were ready to burst."* This was what de¬
ceived the ancients, and was the cause of all their
mistakes. When they found the right ventricle thus
full of blood, they conceived that it alone conveyed
the blood; they found the left ventricle empty, and
believed that it contained nothing but vital spirits
and air; and so far were they from having any no¬
tions 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 con¬
tinually forwards in the veins ; or, if they provided
any way of return for these two fluids, it was by sup¬
posing 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 of blood, and thought its walls were
thinner, because it had only to contain the very
orossest parts of the blood: and why they called
the left ventricle ventriculus spirituosus and no-
bilis, because they saw it empty, and concluded that
it contained the animal spirits and aerial parts of the
blood, and its walls were thicker, they said, to con¬
tain these subtile spirits. They explain to us their
names of arteria venosa ; and vena arteriosa ;
* Page 2G1.
of the heart.
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 pul¬
monic vein was merely a vein, they would still cheat
themselves with a name, and call it Vena Arteriosa:
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 aspeiia 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 doc¬
trine 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 bubbles ; that it spurted out, and
was full of animal spirits ; and thus it became easy
for them to show how safe it was to open a vein
where nothing was lost but gross blood, how terribly
dangerous it was to open an artery, which was beat¬
ing with the spirit of life ; and this they considered
as such an awful difference, that when arteriotomy
in the temple was first proposed, they pronounced it
murderous, and on this reasoning it was absolutely
forsaken for many ages.
But the oldest of our modern physicians soon
7
or TIIE HEART.
568
un a necessity of mixing this blood and animal
spin s ogether, and for a long while could hit on
110 convenient way by which this mixture might be
f, ec, ' ,as a as^ shift, they made the blood exude
through the septum of the heart: and then the cur¬
rent doctime was, that of the blood which came
ri om the livei, one half went into the pulmonic artery
to nouiish the lungs ; the other half exuded through
the septum of the heart, to mix with the animal
spirits. Riolanus was the bitter enemy of Harvey
and of his noble doctrine; and this is the miserable
and confused notion, not to call it a doctrine, which
he trumpeted through Europe in letters and pam¬
phlets. To make good this miserable hypothesis,
Riolanus, Gassendus, and many others^ saw the ne¬
cessity of having side passages through the septum
of the heart. I really believe, from their mean equi¬
vocating manner of talking about these passages,
that they had never believed them themselves.*
" The chyle," says Bartholine, " and the thinner
blood, pass through the septum of the heart, when
the heart is in systole and the pores and passages are
enlarged." Thus did the celebrated Bartholine be¬
lieve the septum perforated. Wallaeus, and Mar-
chetti, and Mollinettus and Monichen, believed it,
and Mr. Broadbecquius of Tubingen proved it.t
But I believe most potently with Haller, that when¬
ever they wanted to show those perforations, they
managed their probes so as to make passages as wide
and as frequent as the occasion required : " Solebant
foramina parare adigendo stylos argenteos in resistens
septum," says Haller ; and this is a full and true
account of all the authors who have described side
passages through the septum of the heart; they
needed them, and they made them.
Amidst all this ignorance, we cannot wonder that
* That I may not seem to speak too harshly of this knot of
conspirators against Harvey, I will quote what Boerhaave says
of Riolanus, who was at the head of them: Non ipse callidus
cavillationum artifex Riolanus, &c.
+ Experimento perforatum ostendit Broadbecquius lubingcE.
ao2
56 4
OP THE HEART.
a thousand childish imaginations prevailed, nor that
the qualities of the mind were deduced from the
physical properties of the 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 myste¬
riously 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 whenever 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 irreso¬
lution and fear, that he is thoroughly surprised when
he finds the contrary : " Cor vastus fuit homo, tamen
audax fuerat, ut cicatrices in capite frequentes et
rimse in cranio testabantur." But if Bartholine be
right, Kirkringius is quite wrong, and has mistaken
the doctrine ; for he says, " An magnanima fuerit
liaec magni cordis foemina, nescio," &c. " I do not
know whether this woman'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 fighters,
I cannot pretend to decide." We have heard the
vulgar talk also of a hairy heart, as familiarly as of a
hairy man, being 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
8
OF THE HEART.
565
fir Physicians? He it was who began with
e ing low the Messenians, that unhappy people,
who lived for so many ages the slaves or helots of
(jreece, lost their great general, Aristomenes. But
how gieat lie was, never, according to Pliny, came
to be known till after his death ; for the Lacedemo¬
nians having catched him three times, resolved at
last to open his breast; and there, as a proof of his
most invincible 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. " There was a robber, (says Beni-
vinius,) one Jacobus, who having been taken down
from the gibbet apparently dead, but really having
in him the remains of life, was laid out carefully,
recovered, was 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 actually found the heart, not covered, but
(refertum pilis) crammed with hair."
But there is, in fact, no end of wonders and won¬
derful dissections among these robbers of his. His
next subject was not a bold robber, but a poor
sneaking thief (de corde furis cujusdam) ; there was
no hair to be expected in his heart: but as he was a
thief only, it was consistent with this doctrine that
he should be first very heartless ; secondly, have
very little brain ; thirdly, that he should have very
inordinate appetites and desires. Now, there was
first a great two-legged vein carrying the atrabilis,
the source, no doubt, of all his inordinate cravings,
directly into the stomach ; secondly, there was a
o-reat 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 wTas the leason (having
o o 3
of the blood*
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, per¬
haps, the history of the absurdities of the human
genius should no more be neglected than that 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.
OF THE RESPIRATION OF ANIMALS,
its effects on the blood.
The effects of oxydation then are, to redden the
blood, to renew its stimulant power, and to commu¬
nicate 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 motion
of the blood through the lungs; and there it is ex¬
posed 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 con¬
sisting merely of air fit to be breathed, but for the
greatest part formed of an air which is most fatal to
animal life, whence it has the name of Azotic Gas.
Of an hundred measures of atmospheric air, we find
twenty-one only to consist of vital or pure air, that
is oxygen ; seventy-nine consist of azotic air, or
of the blood.
*1 °^enj as called, fatal to animal life ; and one
ousandth part only is fixed air, or carbonic acid,
w ic 1 is also an unrespirable air. But of these
wen y-one parts ot pure air, seventeen parts only
ai e a iected by respiration ; so that in respiration we
use much less than a fifth part, even of the small
quantity ot air which we take in at each breath.*
Di. Bostock, atter having examined the various opinions of
the best chemists who treat of the effects produced by respiration
upon the air, concludes thus — " 1, Air which has been respired
loses a part of its oxygen : the quantity varies considerably, not
only in the different kinds of animals, but in different animals of
the same species, and even in the same animal at different times,
according to the operation of certain external agents, and of
certain states of the constitution and functions. Upon an average
we may assume, that a man, under ordinary circumstances, con¬
sumes about 4,500 cubic inches, or nearly 15,500 grains of oxygen
in 21 hours. 2. A quantity of carbonic acid is produced, the
amount of which varies very much, according to circumstances,
both external and internal: its quantity depends, to a certain extent,
upon the quantity of oxygen consumed; but the two are not in
exact proportion to each other: in a great majority of cases, the
quantity of carbonic acid produced will be found to be less than
that of the oxygen consumed ; so that there will be a surplus
quantity of oxygen more than is necessary for the production of
the carbonic acid. In consequence of the variations which take
place in the amount of the carbonic acid produced, it appears
almost impossible to fix upon any number which may indicate the
average quantity; but it may be stated to be somewhere about
40,000 cubic inches in 24 hours. This will weigh 18,600 grains, or
nearly three pounds, and will contain 5,208 grains of charcoal, and
13,392 grains of oxygen, which will be 2,100 less than the
quantity of oxygen consumed. 3. The volume of the air is
diminished by respiration; but this, like the changes mentioned
above, varies so much at different times, that it is almost im¬
possible to form any statement of the quantity : perhaps we may
assume, that air which has been once respired is diminished by
about -g-V of its bulk. 4. It appears probable, that nitrogen is
both absorbed by the lungs and exhaled from them: but the two
processes of absorption and exhalation differ very much, both in
their absolute quantity and in the relation which they bear to
each other ; so that the proportion of nitrogen in the air is some¬
times diminished by respiration - is occasionally increased, and
frequently remains without alteration. 5. A quantity ot aqueous
vapour is discharged from the lungs, mixed with or diffused
through the air of expiration ; but we have not sufficient data
from which to decide upon its amount; and it is probable, that
the quantity varies considerably in the different conditions o t ic
o o 4
OF THE BLOOD.
Within these few years, the following opinions
prevailed on this subject. The air in respiration is
diminished by the abstraction of a part of the
oxygen ; there is formed a quantity of carbonic acid
gas by the union of the carbon of the blood with the
oxygen respired; and there is discharged along with
these a quantity of watery halitus. Therefore atmo¬
spheric 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
oxygen, 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 hydrogen of the blood. Respiration frees
the blood of two noxious principles, the hydrogen
and carbon ; and it insinuates a new principle, viz.
the oxygen, into the blood.*
system, and the different situations in which the body is placed."
JBostoclis Element. System of Phys. vol. ii. p. 110.
* " Two theories have been proposed, in order to account for
the phenomena of respiration. According to one theory, the
carbonic acid found in respired air is actually generated in the
lungs themselves ; while, according to the other, this gas is
thought to exist ready formed in the blood, and to be merely
thrown oft'from that liquid during its distribution through the
lungs.
" The former theory, which appears to have originated with
Priestly, has received several modifications. Priestly imagined,
that the phenomena of respiration are owing to the disengage¬
ment of phlogiston from the blood, and its combination with the
air. Dr. Crawford modified this doctrine in the following manner
(Crawford on Animal Heat): He was of opinion, that venous
blood contains a peculiar compound of carbon and hydrogen,
termed hydrocarbon, the elements of which unite in the lungs
with the oxygen of the air, forming water with the one, and
carbonic acid with the other; and that the blood, thus purified,
OF THE BLOOD.
uc i lias been the opinion of chemists up almost
o e piesent day ; but the rapid changes of opinion,
an , indeed, of whole systems, and the confusion
into which the discoveries of the day throw the result
o a pieceding labours, would almost provoke an
anatomist to put out ot his system the chemical dis¬
cussion altogether, until the masters of that science
have ai rived at acknowledged principles. More
careful experiments have proved that the volume of
air expired is very nearly the same with that inspired,
— the respired air differing only in the variable pro¬
portion ot carbonic acid gas3 and aqueous vapour;
that all the oxygen taken from the atmosphere
respiration is consumed in the formation of the car¬
bonic acid gas found in the respired air; and that
regains its florid hue, and becomes fit for the purposes of the
animal economy.
" The hypothesis of Crawford, however, is not merely liable to
the objection that the supposed hydrocarbon, as respects the
blood, is quite imaginary, but was found at variance with the
leading facts established by Messrs. Allen and Pepys. By the
elaborate researches of these chemists, it was established, that
carbonic acid gas contains its own volume of oxygen ; and they
also concluded, that air, inhaled into the lungs, returns charged
with a quantity of carbonic acid, almost exactly equal in bulk to the
oxygen which disappears ; an inference which, as applied to man
and some of the lower animals, seems very near the truth.
" A review of these circumstances induced them to adopt the
opinion, that the oxygen of the air combines in the lungs ex¬
clusively with carbon; and that the watery vapour, which is
always contained in the breath, is an exhalation from minute pul¬
monary vessels. They conceived that the fine animal membrane
interposed between the blood and the air does not prevent che¬
mical action from taking place between them.
" According to the second theory, which was supported by
La Grange and Hassenfratz, and has lately been adopted by
Dr. Edwards, carbonic acid, generated during the course of the
circulation, is given off from the venous blood in the lungs,
and oxygen gas is absorbed. . ..
"In the experiments of Dr. Edwards, on confining frogs and snails
for some time in an atmosphere of hydrogen, the residual air was
found to contain a quantity of carbonic acid, which was in some
instances even greater than the bulk of the animal; ami a similar
result was obtained with young kittens. Turner s Elements of
Chemistry, p. 753.
of animal heat.
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
of capacity in the blood.
The change produced in the blood during the cir¬
culation in the lungs, is simply to free it of the
superabundance of carbon with which it is loaded
by circulation through the body.*
of animal heat.
The next effect of respiration is the communi¬
cating of heat to the body. There are some who
* " In studying the subject of respiration, the first object is
to determine the precise change produced in the constitution of
the air which is inhaled. Dr. Black was the first to notice that
the air exhaled from the lungs contains a considerable quantity
of carbonic acid, which may be detected by transmission through
lime water.
"Priestly, some years afterwards, observed, that air is rendered
unfit for supporting flame or animal life by the process of respir¬
ation, from which it was probable that oxygen is consumed;
and Lavoisier subsequently established the fact, that during
respiration oxygen gas disappears, and carbonic acid is disengaged.
The chief experimentalists who have since cultivated this depart¬
ment of chemical physiology are Priestly, Scheele, Lavoisier,
Seguin, Crawford, Goodwyn, Davy, Ellis, Allen and Pepys,
Edwards and Despretz ; of these, the results obtained by Messrs.
Allen and Pepys, and Dr. Edwards, are the most conclusive and
satisfactory, their researches having been conducted with great
care, and aided by all the resources of modern chemistry.
" One of the chief objects of Messrs. Allen and Pepys, in their
experiments, was to ascertain if any uniform relation exists
between the oxygen consumed and the carbonic acid evolved.
They found, in general, that the quantity of the former exceeds
that of the latter; but as the difference was very trifling, they
inferred, that the carbonic acid of the expired air is exactly
equal to the oxygen which disappears. The experiments of
Dr. Edwards were attended with a remarkable result, which
accounts very happily for some of the discordant statements of
preceding inquirers. He found the ratio between the gases to
vary with the animal. In some animals it might be regarded as
nearly equal; while in others, the loss of oxygen considerably
exceeded the gain of carbonic acid, so that the respired air
suffered a material diminution in volume. With respect to the
human subject, the statement of Allen and Pepys seems very
near the truth." Turner s Elements of Chemistry, p. 750.
OF ANIMAL HEART.
pie end to say, that when they draw in vital air, they
66 a11^(rn^al warmth in the breast, diffusing itself
o\ei a 1 the body ; but it is easy to feel in this way,
fn^ way' w^en a favourite doctrine is at stake,
while those who know nothing about doctrines breathe
the vital aii without any peculiar feeling which they
can explain.
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 the vast effect of heating the whole body. But,
were it so, we should feel a burning heat in the
centre, a mortal coldness at the extremities, and
marked differences in the heat of each part, in pro¬
portion 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 they warm them up
to the right temperature without overheating the
whole body ? When a part was inflamed, how could
the heat go from the lungs, particularly to that point,
and rest there ?
It is a law of nature, to which, as far as we know,
no exception is found, that a body, while it passes
from an aerial to a fluid form, or from a fluid to a
solid form, gives out heat. So, it might be said, what
is the whole business of the living system but a con¬
tinual assimilation of new parts, making them con¬
tinually pass from fluid into a solid form ? But this
would be an erroneous view of the matter.
It were easy to say, that the gases were consumed
in breathing, and the fluids in circulation became
solids, and therefore heat was generated in the
animal body. But, unfortunately for this hypothesis,
these solids are again melted into fluids, and the
fluids are giving out gases ; and then as much heat
as we might suppose was generated in building up the
fabric of the body would be lost in its decomposition.
OF ANIMAL HEAT.
This is a subject of much difficulty, as may be
readily conceived, when we consider, that for its elu¬
cidation we require to measure the air, and estimate,
not the temperature of that air, but the degree of
heat it is capable of producing : we are consequently
engaged with chemical processes of great delicacy.
The received opinion is this; bodies and even fluids
and gases have different capacities for heat, and the
heat may make a part of their compound, without
being in a state to raise their actual temperature:
this property of latent heat was the great discovery
of Black. Now it is said that the blood, when going
out from the heart to the lungs, differs in its capa¬
city of absorbing and retaining the heat from the
same blood on its return ; that the arterial blood,
returning in the veins, contains more absolute heat,
though it be not of a higher temperature than the
blood of the veins. By the process of respiration,
when the purple-coloured venous blood is exposed
to the air, it throws out its superabundant carbon:
and when this carbon unites with the oxygen of the
air respired, carbonic acid gas is formed and heat is
evolved. The arterial blood, it is supposed, takes
up this heat, which is not sensible heat, but latent.
It is further alleged, that when the arterial blood is
conveyed along the tubes and vessels to the body,
and generally diffused, it is not heating the body,
because the latent heat is not disengaged, and is not
in a state to raise the temperature. But when that
arterial blood is converted into venous blood, a
process which takes place in the extremities of the
arteries and veins of the body, then the latent heat
is disengaged, because the venous blood has not the
same capacity for retaining it as the arterial blood
had: and thus heat is uniformily diffused in propor¬
tion to the activity of the circulation—in proportion
to the conversion of arterial into venous blood.
This highly ingenious hypothesis of Dr. Crawford
has been objected to by Dr. Davy, Edwards, and
others, who assert that there is 110 difference of capa¬
city in the arterial and venous blood. And the
phenomena are explained in this manner : it is said
OF ANIMAL HEAT.
fL_ ?xy&en is absorbed by the blood returning from
to. the left side of the heart: that this
wlflf t!'' cau/e<l by the arteries over the body, unites
nn 1 fl f ?ar. ^ ^n. the circulation through the body;
i ,a * 1S during the assumption of this carbon,
and the formation of carbonic acid, that heat is
evolved. Ihis appears to me to be a defective
hypothesis, inasmuch as there are only two ways of
explaining a change of temperature, — either by a
diffeience of capacity of retaining what was formerly
called latent heat, or by a difference in the aggre¬
gation or condition of the substances. They^have
rejected the hypothesis of the different capacities of
heat. As to the other, they have not explained to
us how the carbon, constituting a part of the solid
texture of the frame, should give out heat when
entering into the liquid blood, we may say when
changing from the solid to the liquid state. We
require a new genius to look over this subject, and
to arrange the discordant materials. In the mean¬
time, by rejecting the hypothesis of Crawford we are
thrown into more confusion : but the truth is, that
in every subject, where the experiments and reason¬
ing of the chemist are brought to explain a vital
phenomenon, he fails in being perfectly satisfactory.
It is by possessing this property of animal heat
that we are enabled to resist the changes of external
temperature, and maintain a genial warmth inde¬
pendently of the surrounding atmosphere. Thus man
can inhabit all parts of the globe, however various
are the degrees of heat in the different climates ; and
his temperature is always the same, being 97° or 98°.
As to the means by which the uniformity of the
animal temperature is thus preserved, the inves¬
tigations of chemists have not yet conducted us to
very satisfactory conclusions. It is supposed that
the quantity of carbonic acid gas evolved from the
lungs and the halitus may vary according to the
altered state of the surrounding temperature ; and it
is also thought that the degree of perspiration of the
skin, and the consequent evaporation, may vary in a
OF THE MEMBRANES
similar manner, so as to correspond with the warmth
or coldness of the atmosphere—but of these the
proofs by actual experiment are yet very deficient.*
OF THE MEMBRANES OF CAVITIES, AND PARTICU¬
LARLY OF THE MEMBRANES OF THE THORAX.
Every part of an animal body, with the exception
of the fluids, the matter of the nerves, of the mus¬
cles, and of the bones, is resolvable into membrane
by maceration, and the contrivances of the anatomist.
The fine web which supports the retina in the eye,
and the strong cord 011 which the gastrocnemius
acts, are formed of the same kind of tissue, the same
cellular texture. Another remarkable circumstance
isj that this cellular texture no where terminates, and
that the membranes of the body are every where in
continuity. If, for example, we begin our investi¬
gation with the tendon of a muscle, we shall find that
* It was conceived, from the experiments made by Boerhaave,
that persons could not live when exposed to a heat greater than
that which is natural to the body. This was first disproved by
Tillet, who gave the account of some young women, the servants
of a baker at Ilochefoueault, who were in the habit of going into
the heated ovens at the temperature of 278°; and they could
remain in them for about 12 minutes. Subsequent experiments
have been made by Dr. Fordyce, Blagden, Dobson, and others ;
and it has been found, that although the temperature of the
surrounding air be raised to 260°, the heat of the body suffered
scarcely any change from its usual standard: it varied in their
experiments between 98° and 100°. When many persons were
together in the heated chamber, the temperature of the room was
changed — it became much less. It was then supposed by
Dr. Blagden, that independently of the cooling effects of the
perspiration, their bodies had a property of abstracting and
removing some of the heat. When they breathed upon the
thermometer, the mercury fell — they cooled the tips of their
fingers by blowing upon them. The pulse, during these experi¬
ments, rose, in some instances, to 130°. Their breathing was not
affected.
Captain Lyon, while in Winter Isle, which is situated N. lat.
66° 11;, and while the temperature varied between 33° and
3°, made observations with the thermometer on recently killed
foxes, and he found that the degree of heat of their bodies
was always between 106f° and 98°.
Dr. Davy states, that the standard heat of the inhabitants of
Ceylon is two degrees above the usual standard.
OF CAVITIES.
! 18 'cjso^vable into a twisted membrane, we may
/a(JG , 118 membrane into the muscle, and we shall
nc enveloping the muscular fibres, and extending
loug i tie muscle, and uniting again to form the
tendinous insertion of the muscle into the bone,
riom the tendon the continuation is direct to the
penosteum ; tlie periosteum is continued into the
ligaments and capsule of the joint; from this again
we may trace the fasciae, and intermuscular septa.
I hese firmer structures we shall find loosening into
the common cellular texture, and that texture, as
has been already explained, may be traced over the
whole animal frame.
But we have now particularly to consider the
structure and connections of the membranes of the
great cavities of the body; and, in the first place,
the membranes of the thorax.
A membrane is an expansion or web of animal
matter, having extension with a scarcely measurable
thickness ; it has one surface, free or disunited, and
smooth, and lubricated with a secreted 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 membranes ; 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 secretions. The
object of the secretions is to prevent adhesion of
contiguous surfaces, which is most effectually done
by the mucous secretion. But as the mucous secre¬
tion is not readily soluble, nor prepared for absorp¬
tion ; 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 j so that it is supplied to moisten
OF THE MEMBRANES OF CAVITIES.
the surfaces of shut sacs, and membranes which are
continuous and have no outlet, such as those lining
the great cavities. But if there be 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 coagulable 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 lining 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 bronchia, and finally, into the bron¬
chial cells, an extent perhaps equal to the whole
surface of the body.
To trace these continuous surfaces is not an idle
minuteness; for we require to know, that inflamma¬
tion will creep along the surface by a prevailing
action, which has got the name of continuous sym¬
pathy. Thus we are sensible in catarrh of a sense
of pain and weight in the forehead, commencing
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, andthus the inflammatory action terminates only
witli the extremity of this long line of connection.
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 some-
of the pleura.
times tiace the course of inflammatory action. An
ery ematous blush, visible in the throat, will some-
lmes take its course in a very dangerous manner,
^ f. ®x.^en^ the canal, even to the anus.
I e third division of this membrane is where the
rore-skin is reflected over the extremity of the penis
into the urethra : here the mucous secretion com¬
mences, and it characterizes the whole extent of the
canal, tiacing it through the bladder to the pelves 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 perceive that the serous mem¬
branes form the outward surface of the same viscera,
investing both the solid and membraneous viscera
with a common covering. The course of the serous
membranes is, however, by no means so simple nor
so easily comprehended by the student, as that of the.
mucous membrane : at the same time that they are
reflected from one viscus to another, they form a
shut pouch or sac. 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 blood 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.
By this it will be understood that there are two
pleurae: that which lines the central cavity has
another name. Taking the membrane of one side
we may thus describe it. The pleura is the fine
serous membrane forming a bag which lines the
cavities of the chest, and is reflected upon the lungs.
We shall consider the pleura first as it lines the ribs
(and where it is called pleura costalis) ; secondly,
where it is reflected on the diaphragm ; thndly, as
vol. i. p p
op the pleura.
it forms the septum dividing the chest; fourthly, as
it is reflected to cover the lungs (where it is the
pleura PULMONALIs).
The pleura costalis is the lining of the lateral
walls of the chest. These walls consist of the ribs,
their cartilages, and the sternum, their interstices
being filled up with the intercostal muscles. The
lining membrane of course is attached in part to the
inside of the ribs, in part to the muscular texture
which intervenes. It is a simple membrane ; for so
we call it, although, like every other membrane, it
may be divided into layers of cellular membrane.
On its outer surface it is more loose and cellular in
its texture ; on the surface towards the cavity it is
smooth and bedewed with secretion, and is un¬
attached or free. 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 fore parts, the diaphragm
forms the floor of division betwixt the cavity of the
chest and the lower cavity, or abdomen. 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
partition of the chest which is called mediastinum ;
which completes the circle of connections, as far as
relates to the lateral cavity of the chest.
To understand whether or not we should speak
of one or more membranes under the name of pleura,
we must understand what is meant by cavity, and
how many cavities there are.
We speak continually of the cavities, when cor¬
rectly there are none in the animal body ; for there
is no empty space : the heart and lungs, with their
membranes, lie in close contact. But when the
anatomist exposes these viscera, the air rushes in,
and there are then cavities. Or if, in the living
body, air should escape from the lungs, or blood or
secretion should be deposited betwixt the mem¬
branes, then, correctly speaking, such fluid lies in
the ccvvity. It would, therefore, be affectation to use
OF THE PLEURA,
ot'lei term, and with this explanation no false
conception can be formed.
•f cav^es there are three in the thorax, the
c vi y 01 t le heart, nearly in the centre, and the
two lateral cavities for the lungs. For although the
lungs 01 m one organ, yet being extended in two grand
divisions laterally, and these divisions contained in
dineient cavities, and embraced by distinct mem¬
branes, we speak of them as double, and call them
the lungs.
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 pulmonalis.
In the first plan here, the dotted line represents
the course of the pleura, in a supposed section of
the chest. Two lateral cavities are seen with a par¬
tition ; that partition or septum is the mediastinum,
and passes from the spine to the sternum, dividing
the chest into two lateral cavities. The second
plan shows the manner in which the pleura is re¬
flected to cover the lungs and form the pleura pul¬
monalis : a dotted line still marks the course of the
membrane ; and here we may observe, that when
the pleura has formed the septum, called medias¬
tinum, it is there again reflected over the vessels
goino* to the lungs, and, covering the vessels, pro-
tects& them, and forms what is called the ligament of
the lungs. Tracing the membrane in its course, we
do not find that it terminates any wherej we find
pp2
580
of the pleura.
that it is every where continuous, and that the pleura
pulmonalis and pleura costalis are the same continued
surface of membrane. So that were it possible to dis¬
sect it all out, without a hole in it, it might be blown
up like a bladder. It is unnecessary to say that such
a dissection will not be attempted.
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 follow 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.
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 contact,
and yet do not adhere, and that consequently free¬
dom is given to the motion of the lungs. At least,
if in respiration the lungs do not move from the sides
of the chest, they are not prevented by the adhesion
of the pleura, when in a healthy and natural state,
but by a circumstance already in part explained.
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 be¬
twixt the lungs and ribs.
The ligaments of the lungs are understood when
my reader 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 pleura takes
13
of the mediastinum.
}C?' e tracing the tubes and vessels going to the
u s ance of the lungs, it forms ligamentous roots,
^ natural connection of the lungs to the chest,
e mediastinum is a partition dividing the great
CfV\^i °j chest into two lateral parts: it is
stretched from the spine to the sternum. This is a
common and it may be a true description of the
mediastinum, as far as it goes, yet it is a most imper¬
fect one. T_ his partition of the thorax is esteemed a
piovision 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 betwixt the ribs of one
side, may still breathe with the other, I would venture
to say, that it is a wrong reading in that volume which
it ought to be our pride to preserve pure. Every mo¬
tion of the natural system has its proper check ; every
delicate part has its guard against the violent motions
of the natural 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 consump¬
tion. I cannot believe that there is either in the fora¬
mina of the heart, or the mechanism of the chest, a
provision against the effects of disease. I have there¬
fore 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 which the body is subject in health. But
I have said that the description of the mediastinum is
imperfect; and really, though seemingly simple, it
is difficult to represent by words the connection of
the membranes of the thorax.
The two distinct sacs of the pleura, each forming
a lining membrane to the two sides of the thorax,
approach towards the centre of the cavity, and would
absolutely unite but for the intervention of the heait
p p 3
OF the mediastinum.
and its appendages. And so, indeed, it is, that an¬
terior to the heart and posterior to it these mem¬
branes nearly touch. Where the sacs of the pleura
approach each other anterior to the heart, they form
the anterior mediastinum ; and in the same man¬
ner, 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 mem¬
brane ; 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 medi¬
astinum contains the thymus gland, some absorbent
glands, and a considerable trunk of the lymphatic
system, which has been called the ductus thora-
cicus anterior.
The posterior mediastinum, called sometimes
dorsale, contains the extremity of the trachea and
part of its branches called bronchia, and part of the
pulmonic artery and veins ; the oesophagus, for the
greater extent of its course; the descending aorta,
and the great trunk of the absorbents ; the thoracic
duct; the eighth pair of nerves; the vena azygos,
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 connections of the membranes
of the chest with the heart and great vessels. The
pleura, which is a very thin and weak membrane
where it invests the lungs, or adheres to the inside
of the ribs, is particularly strong where it is reflected
from the diaphragm ; and from the diaphragm to
the upper and more contracted part of the chest, all
along the tract of the cava, it is of a ligamentous
firmness, and is more like a fascia or tendon than
those layers of cellular tissue which have of late got
that name in connection with the subject of hernia.
Towards the upper part of the chest, the pleura, or
rather the mediastinum, covers and embraces the
8
OF THE MEDIASTINUM.
583
lane ies of the cava, and posteriorly it covers and
pio ects the aorta and thoracic duct; in short, were
i not tor the fear of confounding the ideas of the
younger student, I would say, that this structure of
membianes excludes all but the lungs from the cavity
or the chest, and consequently from the effect of the
chest s motion in respiration. How the respiration
does not affect the veins and cavities of the heart
will now, I trust, be easily conceived, and conse¬
quently 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 double ; that is, the cellular texture
acquires a different structure, has a ligamentous firm¬
ness, 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 of the arch of the diaphragm. But this
motion, which expands the cavities of the chest, and
consequently the cells of the lungs, and draws the
air into them, would disorder the heart's motion,
would cause a lodgment of the blood and distension
of the great veins and sinuses, were they under the
influence of the motion of respiration, as the lungs
are. But the diaphragm moves chiefly on its lateral
parts ; it is checked and interrupted at the middle part
by the connections of the mediastinum. In propor¬
tion as the lateral cavities of the chest, and the lungs
consequently, suffer the influence of this expansion
of the chest, and have the pressure taken from them,
the parts contained in the mediastinum, on the con¬
trary, 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 to which the
lungs are, they would be subject to the same change
of quantity of what they contain ; that is, the blood
would be accumulated in inspiration, and forced out
p p 4
OF THE PERICARDIUM.
from them in expiration, as the air is in the lungs,
and the regular action of the heart would be thus
interrupted or disturbed.
There is a further use in these connections of the
membranes surrounding the great vessels with the dia¬
phragm, viz. to support or produce an equal pressure
upon the great vessels of the trunk during the violent
actions of the body. Thus in leaping, pulling, or
straining, there is a sudden and great pressure on
the viscera and veins of the abdomen, 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 overpowered and burst but for the protection of
the mediastinum. It is then that we perceive the
happy influence of the diaphragm, in drawing down
the mediastinum, and consequently restraining and
supporting the heart and great vessels.
OF THE PERICARDIUM.
The pericardium, or heart-purse, is the third cavity
of the thorax ; but here again I must caution my
readers on the use of the term cavity. The peri¬
cardium closely embraces the heart, retains the lubri¬
cating fluid, and restrains and limits the heart's
motion. But this being already explained, I have
only to add a circumstance slightly noticed under
the former head. The pericardium is a double
membrane : the inner layer of membrane belongs to
the class of serous membranes; the outer is quite of
a different character, being a tissue of strong fibres
which form a web as strong as a fascia. It is this
external layer of the pericardium which is continued
upon the great vessels as they arise from the heart,
and which forms their supporting sheath ; and what
the closer texture of the sheath does to restrain and
support the arteries and veins, is done by this out¬
ward layer of the pericardium of the heart.
The next point left unexplained is the manner in
which the heart and pericardium are embraced by
the pleura.
OF THE THYMUS GLAND.
585
In this plan* we see how the heart, surrounded
by the pericardium, is further embraced by the
mediastinum, by which it is not only supported, but
the great vessels are surrounded and led securely out
of the thorax, until they reach their proper sheaths
in ascending upon the neck, or passing oat into the
axilla.
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 cellular membrane of the anterior
mediastinum, but stretches upwards on the neck,
and its extremities are betwixt the trachea and caro¬
tid arteries, but it lies principally on the pericardium.
It has two superior cornua, and two inferior, the
right of which is the longest. On puncturing this
gland a white fluid may be expressed, and when we
blow into this puncture the air pervades the whole
gland, giving the appearance of a cellular texture:
but no ducts have been discovered. 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
* A, The heart. B, the pericardium. CC, the pleura of the
right and of the left side, embracing the pericardium betwixt
them.
586
of the lungs.
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 diverti¬
culum chyli; it has been supposed to secrete a fluid
to attenuate the blood; it has been supposed to
separate a peculiar fluid which was again thrown
into the blood through the small veins ; it has been
supposed useful to fill up the thorax during the con¬
tracted state of the lungs in the foetus ; forgetting
altogether that it is large in the foetus, and diminishes
after birth; it has been supposed to protect the
lungs from the pressure of the sternum ; all which
are suppositions merely, that have not the most
distant proof to support them, and yet possess not
sufficient absurdity to make them worthy to be recol¬
lected on that account.
OF THE LUNGS.
The lungs are the soft compressible bodies which
fill the two lateral cavities of the chest; and their
use is to convey the atmospheric air into contact
with the circulating blood. They consist prin¬
cipally of a cellular texture, and air tubes commu¬
nicating 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 Arm texture of mem¬
brane necessary to support them. Their function is
respiration. It is through the larynx, trachea, and
lungs, that we respire ; and respiration is a compli¬
cated as well as an important function. It carries
away the superfluous carbon of the blood ; bestows
heat, and stimulates the system ; endows us with the
power of speech ; affords us the sense of smelling, or
greatly contributes to the perfection of the sense ;
while the lungs bestow due buoyancy to the bodies
of man and animals.
of the trachea, or aspera arteria.
In form the lungs correspond to the cavity which
contains them. When taken from their place and
ex ended, they are wide below, forming a base, and
rise conically upward; they are concave where they
le on the arch of the diaphragm, obtuse above, con¬
vex forward, and more slightly so on the sides ; their
borders behind are obtuse, while they are pointed,
and thin before. The lungs have a deep sulcus be¬
hind, left for the spine, and within the projecting
lobes there is a place of lodgment for the pericar¬
dium and heart.
Attending to this general form, we see why the
lungs are spoken of as double, for, unless by the con¬
nection 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 perfectly
alike. On each lung a fissure begins a little above
the apex, and runs obliquely forward and downward
to the base. This fissure on the left side divides the
lung into two lobes. On the right side there is a
lesser fissure, which consequently forms a less inter¬
mediate third lobe.
of the trachea, or aspera arteria.
The trachea is that extent of the wind-pipe which
is betwixt the larynx (already described) and the
forking or division of this tube where it is about to
enter the lungs. It is seated on the fore part of the
neck, and anterior to the oesophagus or gullet. An¬
teriorly it is covered by the thyroid gland and the
flat muscles, which go from the sternum to the os
liyoides and thyroid cartilage, and all around it has
a very loose and elastic cellular membrane to permit
it to move in breathing, swallowing, &c.
The trachea is not a perfect cylinder, it is quite flat
on the back part and membraneous ; it is rigid to ad¬
mit of the easy passage of the air through it, and this
rigidity is derived from the cartilaginous hoops of
which it is principally formed. These hoops are not
588
OF THE TRACHEA, OR ASPERA ARTERIA.
perfect circles. They are deficient on the back part,
and this deficiency is not only calculated to permit
the tube to be flat on the back part, and to give
place to the oesophagus, but to allow a more perfect
elasticity ; for the extremities of the cartilaginous
hoops being free, their elasticity is thereby increased.
The hoops of cartilage are not perfectly regular:
above they are most so, and are broader; but they are
more irregular, and have weaker cornua, the nearer
the bifurcation : the cornua have transverse fibres
uniting them, which 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; but it has many pores or fora¬
mina opening upon it, especially about the larynx
and epiglottis. These are the openings of the ducts
of the bronchial glands, and on the outside of the
membrane round and oval glands are visible. These
glands are often diseased, inflamed, and ulcerated.*
The moisture which bedews the trachea is a limpid,
bland mucus, which subsides in water, unless air-
bubbles be in it. The thinner part of this secretion
is carried off by the air which passes through the
trachea, and the thick matter is expectorated.
This secretion, which in the healthy state is of the
consistence of thin jelly, transparent and of a bluish
colour, becomes from inflammation of the catarrhal
kind, thinner and more transparent, and is copiously
expectorated. In more chronic inflammation the
matter becomes thick, opaque, and of the colour of
straw. And in a still later stage it may become puru¬
lent, without implying lesion of surface. The firmer
nodules of viscid secretion which are brought up
are probably from the sacculi laryngis.
From its exposed situation, its sensibility and vas¬
cularity, the membrane of the trachea is very sub-
* Glandulce bronchiales conglobates, mentioned by different
authors, are no more than the conglobate lymphatic glands,
seated around the bronchia at the root of the lungs and in the
mediastinum, and which belong to the lymphatics of the lungs.
THYROID GLAND.
jec o disease. I have now before me examples of
geneial inflammation, of inflammatory crust, of sup-
pura ion, and deep ulcer in the inside of the trachea.
en lesser degrees of inflammation change the
nature of the bland secretion, making it more saline,
acnd, and stimulating. Sometimes the inflammatory
action will mix a portion of coagulable lymph with
the mucus secieted, and which, by this addition, will
take a tubular form, as in the croup. But let it be
remembeied, that coagulable lymph in the form of
tubes or vessels may be coughed up from the lungs,
a consequence of blood poured into the bronchia,
without the presence of inflammation.
OF THE THYROID GLAND.
The thyroid gland is composed of two distinct
glandular portions, of an oblong shape, which oc¬
cupy the sides of the larynx, and which are united
at their lower part by a narrow isthmus or band ex¬
tending across the trachea below the cricoid cartilage.
It varies considerably in its shape and size. But each
lobe is generally thickest at its lowest end, and as it
ascends gets more peaked. At its lower part it comes
more forward, and partially embraces the two upper¬
most rings of the trachea ; but higher up, it recedes
backwards so that the uppermost point lies more
upon the inferior constrictor pharyngis than upon
the thyroid cartilage. The sterno-thyroidei, sterno-
hyoidei, and omo-hyoidei muscles all cover the gland.
It clings around the larynx, and follows it in all its
motions. Each lobe lodges upon the sides of the first
rings of the trachea, and part of the cricoid and thy¬
roid cartilages. The muscles upon which it lies are
the crico-thyroidei, thyro-hyoidei, and inferior con¬
strictor of the pharynx. Sometimes there is a slip of
muscular fibres descending from the os hyoides, and
which expands upon its surface : this has been called
the levator glandulae thyroid® — but it is not always
present. Sometimes muscular fibres are seen extend-
iii"- over the gland, appearing to be a part of the
cnco-thyroideus muscle. On cutting into the gland
of the bronchial tubes.
its texture is seen to be very vascular, and a watery
or viscid secretion can be squeezed from the cut
surface. It is subdivided into distinct lobules, but
these are not so obvious as in the salivary glands.
Anatomists have failed in discovering an excretory
duct for this gland ; yet some have mistaken a vessel
for it. It is observed to be in general larger in the
female than in man — it is also observed to be pro¬
portionally larger in the foetus than in the adult.
Whatever other function may be discovered to be
the office of this gland, I conceive it to be, in an
essential degree, part of the organ of the voice : that
the muscles which are over it compress it against the
cartilages of the larynx, and influence their vibra¬
tions.
of the bronchial tubes.
On entering the thorax the trachea inclines back¬
ward, and passes into the posterior mediastinum, and
behind the arch of the aorta, and before the oeso¬
phagus ; opposite to the third vertebra of the back
it divides into two branches, passing to the right and
left; these and their subdivisions are the bronchia.
When we follow one of these tubes, we find it
entering the substance of the lungs, accompanied by
blood vessels, branches of the pulmonary artery, with
their corresponding veins; and lesser arterial branches
enter here, which are derived from the aorta, and
are called the bronchial arteries.
The bronchia divide and subdivide in regular
order, branching like a tree through all the substance
of the lungs, until their tender extremities terminate
in the air-cells ; for the cartilages of the bronchia,
which near the trachea resemble those of the trunk,
become annular and weaker, more oblique, irregular,
and further removed from each other, until the ex¬
tremities are little more than membraneous tubes.
of the bronchial cells.
The bronchial cells, into which the air is ad¬
mitted in respiration, have been represented as very
OF THE BRONCHIAL CELLS.
bron T" S^^ler^c^es attached to the branches of the
nthpC Va' ar»d having no communication with each
M' 1 * • !leld .toSether by a minute cellular texture.
a P]g 11 described them as round vesicles, as if the
fane les ot the bronchia were dilated into clusters of
is met bags. Willis described them like myrtle-
beines on the stalk. Hales estimated that those
cells were in diameter the hundredth part of an inch,
and the extended surfaces of them 1035 square
inches. Keil estimates their whole number to be
1,744,186,015.*
Various attempts have been made to ascertain
how much air the lungs are capable of containing
when distended, and of emitting when the chest is
compressed : but we cannot depend on their results
being very precise. It is pretty generally agreed
that, on an average, 40 cubic inches are alternately
taken in and expelled at each ordinary act of respi¬
ration. It is supposed that about 170 cubic inches
more may be forcibly expelled after a common expi¬
ration, as by coughing, straining, &c. ; and that after
this the lungs shall contain within them 120 cubic
inches. Proceeding upon this estimate, after an usual
expiration there remain 290 cubic inches of air in the
lungs ; and upon inspiration there are 330, which
is the measure of the capacity of the lungs in their
distended state. Since 40 is about the 4th of 330, it
follows that it is only this small proportion, the 4th
part of the whole air in the lungs, which undergoes
a change during each successive act of respiration.
And we possess the power of expelling, by a forcible
expiration, fully two thirds of the entire quantity.f
So far back as 1788, Dr. Goodwyn, to whom phy¬
siology is much indebted, proved that during the
different states of expiration and inspiration the
lungs are sufficiently capacious to permit the circu¬
lation to proceed uninterruptedly from the right to
the left side of the heart. Before his experiments a
* Hales, Keil, and Leiberkuhn, differ greatly in estimating the
conjoint extent of the vesicular surface.
f See Bostock, Elem. Syst. of Physiol, vol.11, p. 25.
592
OF THE BRONCHIAL CELLS.
confused notion prevailed that the actions of respi¬
ration, the alternate dilatation and compression of
the lungs, was for the purpose of aiding the circu¬
lation of the blood from the right to the left side of
the heart. What has thrown obscurity over this
subject is the interrupted flow of the blood from the
head into the chest during expiration. Physiologists
have attributed to the condition of the lungs that
which is more properly referrable to the condition of
the heart, during the changes to which it is exposed
by the action of the diaphragm on the mediastinum
in respiration.*
On the bronchial cells the ultimate branches of
the pulmonary arteries and veins ramify and inoscu¬
late, and the thin membrane of the cell and the coats
of these minute vessels do not prevent the influence
of the air upon the circulating blood. My reader
must well distinguish betwixt this regular cellular
structure, for the admission of air which is drawn
through the trachea and bronchia, and that cellular
texture of the lungs which is common to them and
every part of the body; this tissue which supports
the air-cells, the bronchia, and the three several
kinds of blood vessels, and the lymphatics which
collectively 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.
Some have contended that there was a muscular
tissue around the bronchial cells ; but it is impos¬
sible to demonstrate this, and I must presume phy¬
sicians have allowed themselves to be misled by
symptoms during life.
Sometimes the air escapes from the proper
bronchial cells into the cellular texture ; then there
is emphysema of the lungs; then the lungs are dis¬
tended with air; but that air does not minister to
the oxygenation of the blood, on the contrary the
patient dies suffocated. And still more frequently
* See vol. ii. p. 50. — See also " The Connection of Life with
Respiration,'' by Dr. Goodwyn.
OF THE ORGANS OF THE VOICE.
lono- ^ lungs being over exerted, as by
iniir~COnti5U^ respiration, a watery or
ous effusion takes place into the common cellular
ex uie of the lungs, which effectually compresses
e pioper air-cells, and after much oppression suf-
tnratpc 1 1
OF THE ORGANS OF THE VOICE.
The organs of speech are very complicated. We
shall first consider how simple sounds are produced,
and then how these sounds become articulated and
expressive of thought. It has been disputed what is
the proper seat of the voice ; and the difficulty of
determining this has arisen from not distinguishing
what is essential to the vibration which produces
sound, and what aids that primitive organ in giving
the voice strength and variety of tone. For the
voice commences in the larynx, but reverberates
downwards into the trachea, and even into the chest,
whilst it may be directed with different effects into
the cavities of the head and mouth and throat.
The organ of the voice is neither strictly speaking
a stringed instrument, nor a drum, nor a pipe, nor a
horn, but it is all these together ; and we will not
be surprised at this complication if we consider that
the human voice is capable of every possible sound
— that it can imitate the voice of every beast and
bird — that it is more perfect than any musical
instrument hitherto invented, and, in addition to
every variety of musical note, it is capable of all
combinations in articulate language to be heard in
the different nations in the earth. 1 he essential and
primary part of the organ is these cords, with which
the reader is already acquainted, the thyio-aiytasnoid
lio-aments, or cordae vocales. The membrane lining
the larynx is reflected over these ligaments, so as to
be drawn by them in their motions, and this is what
is meant when it is said the organ is like a di uni ,
for these membranes must vibrate in the aii. I he
muscles of the arytenoid cartilages draw tight the
VOL. I. Q Q
594
OF THE ORGANS OF THE VOICE.
cordae vocales and their attached membranes, and
thus giving them a certain tension, and the air being
expelled forcibly from the chest at the same time,
they cause a vibration of these ligaments and mem¬
branes. This vibration is communicated to the
stream of air, and sound is produced. This sound,
as we have said, may reverberate along all the pas¬
sages from the lungs to the nostrils; but unless
there be a certain vibration in these cords of the
larynx, there is no vocalization of the breath. For
example, a man, in whispering, articulates the sounds
of the mere breath, without that breath being voca¬
lized and made audible by the vibrations in the
larynx.
In singing, the vocalized breath is given out un¬
interruptedly through the passages, the rising notes
in the gamut being produced first by the narrowing
of the glottis, and secondly, by the rising of the larynx
towards the base of the skull. Physiologists, and
among the rest Richerand and Majendie, make a
comparison between the wind-pipe and a flute or
flageolet. The lower notes of the instrument are
sounded when the fingers cover all the ventiges, and
the sound goes down through the whole tube ; but
as the fingers are raised in succession from below,
the effect is as if portions of the tube were cut off,
and the shorter the tube the higher the note. We
understand then that the sounding tube of the human
voice being lengthened will give out grave sounds,
and these will be higher or more acute as the tube
is shortened. But those physiologists have fallen into
the mistake of believing that the trachea is this tube:
now unfortunately the trachea is elongated in pro¬
portion as the higher note of the gamut is sounded
by the human voice. The comparison should have
been instituted between that portion of the air-tube
which is above the chink of the glottis, and then the
resemblance is just. In the graver notes, the larynx
is drawn down, and the lips protruded; and in the
higher notes the larynx is elevated to the utmost, and
the lips retracted.
of the organs of the voice.
59.5
, .. V ?We^s' as every body knows, are those unin-
nup ed sounds which, commencing in the vibra-
10.n,° .le^arynx> are modified, in ascending, by the
epig o tis, velum pendulum palati, uvula, tongue and
ips, as a. e. i. o. u. The liquid consonants are those
sounds which are partially interrupted by the motion
01 the tongue, as in 1, whilst a sort of continued sound
or di one is permitted. The proper consonants are
shoitei sounds, when the open sound or vowel is sud¬
denly interrupted by the articulating motion in the
tongue and lips, as f. I hose are called explosive,
when the mouth opens to give the sound sudden
passage, as t. The nasal consonants are those where,
although the sound be interrupted in the mouth, it
is made to circulate or vibrate in the cavities of the
head: of this you may become sensible by putting
your hand upon your forehead in sounding the letters
m and n.
Thus the voice may be divided in the sound
which you make in whispering ; when the breath is
modulated and articulated in the mouth, but not vo¬
calized. 2dly, You have it vocalized by the primary
vibrations of the cordae vocales : and these sounds,
though not articulated, may vary to every note of
the gamut, and receive an almost infinite variety of
intonations, by reverberation on the different parts of
the prolonged and varied surfaces of the trachea,
larynx, pharynx, mouth, and cavities of the nose.
Lastly, the vocalized breath may be articulated, that
is, variously interrupted by the tongue, teeth, and
lips and become expressive of conventional lan¬
guage. The uninterrupted sounds are the natural
language, being expressive of the same emotions in
the whole family of mankind ; but the articulate
language is a system of arbitrary signs confined to
rn.intnes or divisions of the earth. Imperfect as this
last appears to be, it is capable of high perfection
and aids in a remarkable manner the developement of
the intellectual powers.
The author has a paper in preparation for the
qq 2
of the blood in the lungs.
Royal Society, in which some of these subjects are
treated of; but it is principally to show that there
has been a singular omission in the accounts hitherto
given of the organs of the voice, more especially of
articulate sounds.
other tubes or vessels which enter into the
texture of the lungs.
Although the blood-vessels which enter into
the composition of the lungs are described else¬
where, yet, as they really constitute the more solid
substance of the lungs, we may shortly review them
here.
The blood-vessels which cling to the bronchia are
called the vasa bronchialia. There are two, some¬
times three, arteries of that name. There are one or
two branches from the anterior part of the descend¬
ing thoracic aorta; sometimes a branch from the
superior intercostal artery; sometimes one from the
subclavian artery. These, taking a serpentine course,
cling to the air-tubes within the lungs. They at the
same time send branches to the mediastinum, bron¬
chial glands, oesophagus, and pericardium.
These are arteries to supply and nourish the mem¬
branes, glands, bronchia, and the other blood-vessels
themselves.
The bronchial veins which correspond with
the arteries. These are two, distinguished as right
and left. The first commonly joins the vena
azygos. The latter goes into the superior intercostal
vein.
The next is the pulmonary artery, that which
arises from the right side of the heart to carry the
dark blood into the lungs : the other great artery of
the system, as distinguished from the aorta. This
artery, bending towards the lungs, divides and sends
its grand right division behind the aorta and the
superior cava, and before the right bronchia. The
OF THE BLOOD IN THE LUNGS.
597
11 anc'h is shorter and straighter, and diverges to
i s c estination. Both of these dive into the sub-
s ance o± the Jungs, and can be traced to great mi-
nu eness. These arteries terminate, like the branches
o le aortic system, in veins. This was the first
part or the great circulation discovered ; and it was
an ancient experiment to push coloured fluids from
the artery into the veins of the lungs. On the
vesicular lungs of the cold-blooded animals, by the
assistance of the microscope, the blood can be seen
moving directly from the arteries into the veins.
The pulmonic veins receiving this blood, and gather¬
ing together their branches from the whole substance
of the lungs, form trunks, and terminate in the left
auricle.
The lymphatics of the lungs form yet another set
of vessels, constituting the substance of the lungs.
They come out superficially in great profusion, and
run their course along the ligaments of the lungs to
the thoracic duct. Most of them run into the
conglobate or lymphatic glands in the posterior me¬
diastinum, called glandulse Vesalii. The nerves of
the lungs are the branches of the par vagum, and of
the great sympathetic nerve.
These parts combined constitute the soft spongy
substance of the lungs, which the ancients, without
much enquiry, called the parenchymatous substance.
COURSE OF THE BLOOD IN THE LUNGS.
Coloured water, or size, or oil of turpentine, being
iniected into the pulmonary artery, comes back by
the pulmonic veins, running in what is called the
lesser circulation. The same fluids being injected
into the vein, return by the artery.* ihe fluid
# Tn an experiment which was made by a pupil of mine, the
t,: was thrown into the crural vein of a live ass, was
found* at' the end of a month to be lodged in the cells of the
" . it had not been forced into the pulmonary veins.
1UI)gS ' Q Q 3
598
OF RESPIRATION.
being more forcibly propelled into the pulmonary
artery, flows by the trachea; and the exudation of
the fluid is facilitated, if the action of respiration be
imitated by blowing into the trachea at the time of
the injection. These coarse experiments in the dead
body prove little ; but the course of the blood from
the extreme pulmonic arteries into the veins, having
been seen in the membranous lungs of the lacertae,
the chymical phenomena exhibited by respiration
leave little for us to wish further in explanation of
the functions of the lungs.#
There are some reflections which naturally occur
in taking leave of this subject of respiration, which
may have the further effect of confirming in my
reader the accurate knowledge of the anatomy.
OF THE MOTIONS OF THE THORAX AND OF
RESPIRATION IN MAN.
We have understood, by our studies of the skeleton
md of the muscular system, how admirably adapted
the thorax is to dilatation and contraction ; and how
the muscles act upon the bony and cartilaginous
apparatus for this purpose. We have seen also that
the cartilages are added to the ribs and sternum, to
give them elasticity, and consequently strength, or at
least a principle of resistance. This elasticity of the
texture of the thorax serves another purpose : it
preserves the chest in a middle condition between its
utmost state of contraction and of dilatation, and
tends to preserve life.
Let us now understand what takes place in the
drawing of the breath.
* For the consent or sympathy of the lungs with other parts,
see the observations under the head of Par vagum, in the descrip¬
tion of the nerves.
OF RESPIRATION.
Tins figure repre¬
sents a section of the
body -(a) the tho¬
rax— (6) the abdo_
men. These two ca¬
vities are divided by
the diaphragm, which
is represented by the
arched line (c); for
the diaphragm as¬
sumes this arched
form especially in ex- /,
piration. When the //
effort is made to in- /:
spire, the diaphragm j j
descends, and then f\\
its state may be re- \\
presented by the dot- ;j
ted line (d). As the \\
diaphragm descends, V
it of course compres¬
ses the viscera in the
abdomen (&), and this
pushes out the abdominal muscles in the form of the
dotted line (./) ; at the same time that the diaphragm
and the abdominal muscles have changed their con¬
dition, the ribs are expanding, and the breast-bone (e)
is rising, so that the thorax is enlarging in all its
diameters. This being the act of inspiration, we
easily understand expiration to be the return of these
parts to their original condition, i. e. the descent
of (e) ; the falling in of (/) ; and the rising of (d)
to (c.)
Let us now take a front view of the thorax, so
that we may have our notions of the action con¬
firmed and corrected. We have the cavities of the
thorax divided by a dotted line; and the floor of
these cavities formed by the arch of the dia¬
phragm (ad)' When the diaphragm contracts and de¬
scends, it cannot uniformly descend as represented in
the lateral plan ; for we have understood that it is tied
OF RESPIRATION.
up by the mediastinum. The perpendicular dark
line represents the mediastinum. Thus the arch (aa),
instead of descending in a single arch, acts on its
lateral parts principally, and assumes the form (bb).
As it was formerly explained, it acts on the lungs
more than on the heart and vessels.
The student who has attended to the anatomy and
relations of the lungs, must perceive that the rising
and falling of the chest, and the propulsion upwards
of the diaphragm (by the abdominal muscles), and
its descent, must influence the lungs, alternately
drawing the atmospheric air into them and expelling
it; and thus the act of respiration is performed, the
lungs being passive. He must perceive that by this
mechanism, in which the whole muscles of the neck,
chest, and abdomen, and back, are concerned, there
is a continual exercise and an incessant motion or
agitation of all the viscera. No doubt this is con¬
ducive to their proper function and to health. He
OF RESPIRATION.
ratus °fi0u^^ a^so °bserve that this extensive appa-
0 "ones, cartilages, and muscles, serve other
Fl oP?^es than of mere breathing: that they assist
1 circu ation of the blood: that they are agitated
vomitino-11^ c°ughing, laughing, crying, smelling,
. ® expulsion ot faeces, &c. He must
perceive this importance in the oeconomy, and must
sure y be desirous of knowing how they are com¬
bined and animated; for which see the Nervous
System. The action of the diaphragm on the cir¬
culating vessels is a subject which for the present I
must reserve.
Although the lungs are very often found adher¬
ing to the inside of the chest, and although this
union occurs where we cannot discover that the
person during life was subject to any inflammation
of the chest, yet it is a preternatural appearance.
The lungs (covered with the pleura) lie in contact
with the sides of the chest, and consequently with
the pleura costalis, but without adhesion. They are
passive in the motion of respiration. The muscles
of respiration clothing the thorax are the agents in
this function. The bony and cartilaginous texture
of the thorax is the machinery put in motion, and
the effect is the dilatation of the lungs ; for as the
sides of the chest rise, the lungs being in close con¬
tact, they must follow this rising; and as the dila¬
tation of the lungs is freely permitted by the en¬
trance of the atmosphere through the trachea into
their cells, the effect of the action of the muscles of
inspiration is the drawing of the atmospheric air into
the bronchial cells, and the contact of that air with
the blood circulating in the lungs. In expiration
the lungs are equally passive as in inspiration. The
muscles which contract the diameters of the thorax
force the compages of bones and cartilages upon the
lungs, and, compressing them, throw out the air by
thThat any other idea should arise in the student's
mind is owing to two circumstances ; first, the not
comprehending the principles of natural philosophy,
602
OF RESPIRATION.
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 sucking-
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 words, the operation of the
weight of the air is permitted to take effect by the
tendency to a vacuum which the rising of the sides
of the thorax produces; the pressure of the atmo¬
sphere then causes the air to descend into the bron¬
chial cells.
The second circumstance which gives occasion to
misconception, 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 ap¬
pears to be owing to a power inherent in them : but
attention to the true circumstance will explain the
occasion of this. When the wound is received the
air enters the chest, and the lungs fall collapsed ;
the cavity is therefore full of air, and the lobes of
the lungs hang loose. The air plays freely out and
in through the hole in the chest. But when by change
of posture the flapping edge of the lungs falls 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 contact witli the pleura costalis.
When the intercostal muscles are dissected off,
and the pleura costalis exposed, the surface of the
lungs is seen in contact with that transparent mem¬
brane; and when the pleura is punctured with the
lancet, the air rushes in, and visibly the lungs retire
in proportion as the air is admitted. This proximity
of the lungs to the ribs explains the effect of fracture
of these bones in producing the tumour called em-
OF RESPIRATION.
physenia, for thus it happens: the broken end of
the rib, piercing the pleura costalis, 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 be¬
twixt 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 accumulates 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 sack, and the man is in danger of
suffocation. The suffocation is not a consequence
of this distension of the cellular 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 mediastinum pressed to the opposite side,
both sides of the chest are oppressed, and the breath¬
ing is so checked, that if not quickly relieved,
the patient would die.
These plans will explain the common case of em¬
physema ;
t+-
604
OF RESPIRATION.
The emphysema of the body may take place in a
different way.* The lungs may be diseased ; air may
be drawn through the abscess, and collect in the
cavity of the chest; or the bronchial and true air-
cells may be hurt by exertion, so that the air gets
access into the common cellular texture of the lungs;
and from the lungs it may find its way bewixt the
ligaments of the lungs into the cellular texture of
the mediastinum, and hence up into the neck and
over the body. These last instances are rare com¬
pared with that proceeding from fractured rib.
* The first plan exhibits a section of the throax, with the rib
broken A, and entering the lungs D. Air has already begun to
accumulate in the cavity of the chest B. The air insinuating
itself by the side of the broken rib, forms the tumour on the side
C. The second plan exhibits the extent of the evil. The lungs
D are compressed. The cavity of the chest left by the retraction
of the lungs is full of air. The emphysematous tumour C is
extended over the body. The right side of the diaphragm E is
pushed down, and the heart and mediastinum F are forced
towards the opposite side, encroaching on the lungs of the left side.
END OF THE FIRST VOLUME.
London:
Printed by A. & R. Spottiswoode,
New- Street- S<] nare.