Additions to the General anatomy of Xavier Bichat

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THE LIBRARY
OF
THE UNIVERSITY

OF CALIFORNIA

PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID

ADDITIONS

CENBRAL ANATOWY

XAVIER BICHAT.

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PROFESSOR OF ANATOMY AND PHYSIOLOGY TO THE FACULTY OF MEDICINE
or pARIs, &c. »

Cranslated from the French, we

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BY GEORGE HAYWARD, M. D. ©
FELLOW OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES,
AND OF THE MASSACHUSETTS MEDICAL SOCIETY.

BOSTON’:
PUBLISHED BY RICHARDSON AND LORD.

J. H. A. FROST, PRINTER.
1823.

“ay

DISTRICT OF MASSACHUSETTS, to wit:
District Clerk’s Office.

BE 1T REMEMBERED, That on the eighth day of January, A. D. 1823, in thé
forty-seventh year of the Independence of the United States of America, Richardson &

Lord, of the said District, have deposited in this office the title of a book, the right whereof

they clai as proprietors, in the words following, to wit :
# itions to the General Anatomy of Xavier Bichat.: By P. A. Beclard, Professor of
Anatomy and Physiology to the Faculty of Medicine of Paris, &c. Translated from the
French. By George Hayward, M. D. Fellow of the American Academy of Arts and

Sciences, and of the Massachusetts Medical Society.”

In conformity to the Act of the Congress of the United States, entitled, «An Act for the
encouragementof Learning, by securing the copies of Maps, Chartsand Books to the Au-
thors and Proprietors of such Copies, during the times therein mentioned :’’ and also to an
Act entitled, ‘* An Act.supplementary to an Act, entitled An Act for the encouragement of
Learning, by securing the Copiesof Maps, Charts and Books, to the Authors and Proprie-

"torsof such Copies during the times therein mentioned ; and extending the benefits thereof
“to the Arts of Designing, Engraving and Etching Historica] and other Prints.’’
Lae

JOHN W. DAVIS,
\ Clerk of the District of Massachusetts.

NOTICE

P Biz
BY THE EDITORS OF BICHAT’S GENERAL ANATOMY.*

WE announced in 1818 an edition of ‘Bichat’s General

Anatomy, to which Messrs. Pinel, Beclard and Laennec, |

were to contribute, and we engaged to give with

faithful a portrait as possible of its illustrious author ; ‘
being editors of the works of Bichat, connected with him
for many years in daily relations and constantly honoured

with testimonials of his esteem and friendship, we owed
this respect to his memory ; but unforeseen circumstances

have prevented the execution of this design by depriving
us of the co-operation of Messrs. Pinel and Laennec.

M. Pinel is compelled to devote to the care of his
health the few moments that are left by his private duties ;
and it is to his son, the worthy inheritor of a name which
will form an epoch in the history of medicine, that we
are indebted for the notice placed at the commencement
of this volume.

* These Additions of Professor Beclard were incorporated into an
edition of Bichat’s General Anatomy, which was published in Paris in

1821; many copies however were issued in a separate form for the benefit
of those who previously owned the works of Bichat.—Tr,

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iV NOTICE

M. Laennec, after a severe disease, has been compelled
to leave the capital, at a moment when he would have
desired to have demonstrated all that can be drawn from
the new mode of investigation which he has made known.

It is then to Professor Beclard alone that we are in-
debted for this volume of Additions which recent works
rendered necessary and which will make complete the
General Anatomy.

M. Beclard has laid under contribution not only the
writings of the French anatomists and physiologists, but:
also all the important works published in Germany and
England, the Treatises of General Anatomy of J. F.
Meckel, J. Gordon, the Prodromus of the great Anatomy
of Mascagni, the Hystology (description of the textures) ©
of Meyer, the Table of General Anatomy of Bock, and
every thing which has appeared upon each texture in par-_
ticular. He has thought proper to add to the history of
each system an article upon its morbid states, and to de-
vote a particular chapter to the preternatural textures.
Most of the facts relative to morbid anatomy have been
derived from the general treatises of Morgagni, Voigtel,
Baillie, Otto, Cruveilhier, and a great number of particu-
lar treatises, among others the excellent work of M. Laen-
nec, who has cultivated this science with so much success.

M. Beclard has added, to the interesting observations
which his researches have furnished him, many which
are peculiar to him, upon the anatomy of man in health
and upon the various alterations of the textures.

_M. Bouvier, who is ranked, from having gained eight
prizes from the Faculty, among the number of its most

BY THE EDITORS. ¥;

distinguished pupils, has assisted Professor Beclard in his
labour, who is pleased to render justice to his zeal and
his information.

All the portraits of Bichat, both engravings on copper
and lithographic drawings,‘are far from being resem-
blances. The medals of the Medical Society of Emula-
tion and the busts even hardly recall any of his features.
We find them rather in the picture of his last moments,
exhibited at the Saloon in 1818. M. Petroz, who pos-
sesses it, has allowed us to consult it, and has entrusted
to us the mask in plaster moulded upon the face of Bichat
some hours after his death. It is by the aid of this piece,
and the advice of all those who, like ourselves, have
known him very particularly, that we have suceeeded
beyond our hopes, since the portrait that we have had
engraved for this edition, when viewed by those whom
Bichat honoured with his friendship, has recalled im-
mediately to their minds the great man whose remem-
brance is so dear to them.

de

HISTORICAL NOTICE
OF

XAVIER BICHAT.

J

IT is easy to enumerate men, who, in the sciences,
have thought for themselves ; their genius opens the path
of discovery and the multitude follows them. Bichat
enjoyed this happy privilege. Anatomy and physiology
will always consider him among the number of those
whose works are the most fruitful in useful results, and
history will assign him one of the first places in that
brilliant epoch of medicine which gave so great an eclat
to the end of the eighteenth century.

Xavier Bicuat, born at Thoirette, in the department
of Ain, on the 11th of November, 1771, pursued his
classical studies at Lyons, and distinguished himself
especially in rhetoric and philosophy. He commenced
in that city the study of anatomy and surgery under Marc-
Antoine Petit. The political troubles of 1793 having ~
soon obliged him to remove from that unfortunate city,
he came to Paris with the intention of perfecting himself

i

Vill HISTORICAL NOTICE.

at the school of Desault, that he might afterwards practise
surgery in the armies. But soon a more brilliant and
extended path opened before him. Having one day writ-
ten down a clinical lecture of Desault, in the absence of
the person whose duty it was, the reading of it occasioned
the greatest sensation. ‘The master knew henceforth how
to appreciate the merit of the pupil. He offered to him
his house, treated him as a son and associated him with
his glory and his labours.

Endowed with an indefatigable ardour, Bichat did not
disappoint the exalted hopes of his benefactor. The
variety,,of his occupations was his only relaxation, and his
methodical mind and wonderful facility made him acquire
with ease all the knowledge which is ordinarily the fruit
of long and painful study.

Bricuar was scarcely twenty three years of age when
Desault died, (in 1795) and so far from being overwhelm-
ed by this unforeseen loss, it appeared to redouble his
activity. The dressings at the Hotel-Dieu, the daily visits
to the patients, consultations, dissections, and operations
on the dead body, had heretofore employed all his time ;
the death of Desault created for him new occupations ;
gratitude made it his duty to publish the researches and
labours of the master who had adopted him. He wished
also then to commence his career as a teacher.

In the winter of 1797 he gave his first course of anato-
my, and his second the year following. After his duty
at the Hotel-Dieu was finished, he superintended the dis-
sections of more than eighty pupils; he performed nu-
merous physiological experiments upon living animals;

fii HISTORICAL NOTICE. ix.

fe
prepared for the press the surgical works of Desault, and
composed memoirs for the Medical Society of Emulation,
of which he was one of the founders.

It was at this period that a revolution took place which
was to change the face of the science. Professor Pinel.
was the first to perceive that a disease can only be an
alteration of textures or of organs ; that it is necessary to

study these organs and. textures, first under the relation
of their structure and then under that of their functions,
before we can arrive with certainty at a knowledge of
their alterations ; and that thus analysis in medicine con-
sists in referring the symptoms, the external signs of dis-
eases, to the suffering and morbid alteration of some
organs ; to study them in their seat, is to derive from the
knowledge of this seat the indications of the treatment,
and finally to class them according to the analogy or the
difference of the affected textures. Such was the original
idea, which presiding over the execution of the Noso-
graphie Philosophique, published in 1798, had just over-
thrown forever that badly constructed scaffolding raised
upon the incoherent plans of the chemical, humoral and
mathematical physicians, and which would lay the first
foundations of a true physical science.

Bicnar, struck with the description and the distinction
‘of the mucous and serous membranes, and especially with
the classification of their diseases, seized this first idea,
made new researches, and extended them to all the mem-
branes of the body ; and in eighteen months after (in 1800)
he published his Treatise upon the Membranes, a model
of precision, originality and analytical method, which was

x HISTORICAL NOTICE.

on

afterwards embraced in his General Anatomy, enriched
with happy developments and new ornaments.

It was a spectacle worthy the regard of history, that
noble emulation, frank and generous rivalship, in this
period of enthusiasm and discovery, should turn every
thing to the advantage of science. If Brcuar owed to
Professor Pinel the idea of his work, the latter in his turn
drew new lights from the researches’ of the young anato-
mist, and corrected in the second edition of his Noso-
graphy the classification of the diseases of the fibrous,
synovial and cellular systems. This alliance of nosogra-
phy with anatomy and physiology, this mutual exchange
of instruction, formed one of the characteristic traits of
this period.

Physiology is the inseparable companion of anatomy ;
the structure of the organs is only interesting as it leads
to researches with regard to their functions; thus the
Treatise upon Life and Death followed soon after the first
works of Bicuat upon Anatomy ; it appeared the same
year. It is in this work that he began to develop that
distinction of the two lives, the organic and animal, which
he has reproduced under a thousand forms, but which
cannot be admitted, as has been proved by Legallois,
without some limitations. The richness of the means’
with which he pursued the development of this idea can-
not be too much admired. The. beautiful experiments
that fill his Treatise, the facts that are made known by
them and the bold and profound thoughts that shine in a
great number of passages, are more than sufficient to make
us excuse some flights of a vivid and ardent imagination.

HISTORICAL NOTICE. xl

Brouat, in his two first works, had only thought of
anatomy and physiology; but the circle of his ideas en-
larging as he reflected on his subject, he ventured to leave
the beaten track, and published in the following year his
General Anatomy, which placed the seal upon his repu-
tation, and which was translated into almost every lan-
guage. Before his time, anatomy had been confined to
the simple description of the organs; he was the first
who thought himself able to rise to bolder views. He
observed that the human body exhibits uniform, identical
systems, subjected to the same laws of growth, nutrition
and diseases ; that these systems, everywhere present,
ean be studied in their strueture as in their functions, so
as to embrace the most general results of their organiza-
tion, and the most fruitful and useful applications. From
that period he created a new science, General Anatomy.
He created for anatomy and physiology, a species of phi-
losophy, to which there was nothing wanting to render it
perfect, but that it should not be limited to the study of
the textures of man. He should have extended his views
to all classes of animals, traced in them the inferiority of
the textures and organs, and observed the properties
which they bore or the new functions to which they are
ealled. Comparative anatomy and physiology would have
furnished to his lively and brilliant imagination the most
novel views, the most substantial. knowledge, and the
most ingenious analogies.

{t is astonishing that Bicuar with that independence
of opinion which characterized him, should have so often
brought forward, in his General Anatomy, those old ideas,

xil HISTORICAL NOTICE.

which for two thousand years have continued ‘in’ the
schools, those words vital force and vital properties,
abstractions which he seems to have taken for realities, to
which he gave a separate existence, and which he made
perform so important a part in the animal economy. Yet
for a long time past we have only recognized and we ought
to recognize but two things in organization, structure and
functions of organ. ‘The philosopher should confine him-
self to the study and-observation of the sensible phenom-
ena which matter exhibits in these two states, without
endeavouring to penetrate further ; beyond, an immense
abyss commences ; we should take care lest we fall into it.
- The General Anatomy contains also the first germs of
a science to which Bicwar would no doubt have devoted
his whole life, I refer to morbid anatomy. It was a
natural consequence of his first labours; after having
studied the structure and functions of the organs, and per-
formed upon living animals experiments for the exact
observation of their phenomena, either in a state of health
or in that of disease, he was naturally led to seek for a
knowledge of the changes in their texture which this last
state brings.

Appointed, at the age of twenty-nine, physician to the
Hotel Dieu, he devoted himself to this kind of research
with all the activity that was natural to him ; in one single
winter he opened more than six hundred bodies, and soon
after he stated in a course of lectures his observations upon
the morbid state of the organs. It was in this ‘course that
he demonstrated that each texture has a peculiar mode of
disease as it has a peculiar character of vitality ; that even

ese

HISTORICAL NOTICE. Xilb

in the intestines,.the morbid state of a membrane can
connect itself with the sound state of the neighbouring
membranes, and that it is very important to know how
to distinguish, by a correct analysis, the peculiar suffering
of these different textures. Bicnar began to unite intoa
body of doctrine the fragments of morbid anatomy scat-
tered throughout his works; he would have raised to the
science a monument worthy of it and of the great epoch
which owed to his labours a part of its distinction. But
he died during the printing of his Treatise on Descrip-
tive Anatomy, the two first volumes of which he pub-
lished himself, (in 1801 and 1802) and left the third im-
perfect. | |
One day, after having visited some specimens of morbid
anatomy subjected to maceration and having been exposed.
without any precaution to their noxious exhalations, he
fell in descending a staircase of the. Hétel-Dieu, and the
slight shock occasioned by this fall. deprived him of his
senses. A violent affection of the head, very severe gas-
tric symptoms, a continual tendency to stupor and ataxic
phenomena succeeded with rapidity, and Brcnat sunk on
the fourteenth day of his disease, 22d of July, 1802.
Thus were turned to bitter regrets the hopes that he was
just realizing ; thus was arrested in his rapid flight this
genius who seemed to hover over the whole edifice of
medical science. Bicnar, embracing in a single view all
the knowledge connected with medicine, saw on the one
hand anatomy brought to the greatest degree of exactness,
physiology established for the first time upon facts, and
the description of diseases reduced to simple and clear

xiv HISTORICAL NOTICE.

language 5 and on the other, morbid anatomy still separ-
ated from physiology, and therapeutics still abandoned to
empiricism. He had conceived the project of connecting
by a regular chain all.the parts of the art of healing, of
raising a complete system of medicine founded upon
anatomy, upon the study of the functions in the state of
health and in that of disease, upon the distinction of the
textures, the sympathy which connects them together, the
observation of the local and the general effects of medi-
cines, and the results of the examination of dead bodies.
He would no doubt have executed this plan, vast and
methodical as it is, which, notwithstanding the preten-
~ sions of some physicians of our time, is yet but a project.
Such is in fact the happy influence which the-great men
who appear from time to time have upon their age, that
from their labours as from an inexhaustible source, new
sciences seem to flow. Those who have nothing to say
continually repeat what has been said ; but before the man
of genius the field of discovery seems to enlarge from day
to day. How many researches has he to make in morbid
anatomy, a physical science, which only considers the
symptoms of diseases as the signs which should be refer-
red to the alteration of the textures, who seeks in these
textures the various lesions produced by the different
degrees of diseases, and who only endeavours to go from
the alterations to the symptoms! How little advanced is
morbid physiology, the knowledge of the functions of the
organs by the different modifications which the alterations
produce in these functions, which will alone resolve an
infinity of enigmatical problems of our organization, and

HISTORICAL NOTICE. XV

especially make known by pathological analysis the dif-
ferent properties of the nervous system! How much has
anatomical chemistry been neglected even to this day,
the research into the composition of the textures, which
would alone be able to establish the identity or the differ-
ence of the systems and the apparatus of the human body!
Pathological chemistry, the investigation of the chemical
changes produced by the alterations in the organs, is it
not an entirely new science, upon which we have hardly
thought, and which will perhaps give the explanation of
many phenomena, whose character and cause we are un-
able to determine by other means?

How many researches has Bicuar opened for us the
way! What an immense inheritance has he left us to
improve! The mind can hardly conceive that the life of
one man was sufficient for so many labours, for so many
discoveries, either made or pointed out; Bicuar died
before he completed his thirty-second year !

SCIPIO PINEL.

GENERAL ANATAOMY.

ADDITIONS

4
GENERAL OBSERVATIONS.

Anatomical Elements.

Page 49, volume 1,. Bichat’s General Anatomy.—
“If you would have only general notions of anatomy,
you can study each organ as a whole; but it is essential
to separate the textures, if you have a desire to analyze
with accuracy its intimate structure.”’

Some have attempted to extend too far this analysis of
the textures ; and, as in chemistry, we recognise in the
organic substances the immediate principles which them-
selves result from the union of the simple elementary
_ bodies, such as oxygen, hydrogen, carbon and azote, they
have sought to discover what are, in the organization of
animals, these primitive elements, the assemblage of
which, variously modified, gives rise to the secondary
textures, to the organic systems of Bichat.

3

18 ADDITIONS TO THE

The ancients had already admitted an elementary fibre,
(fibra simplicissima) composed of earthy particles united
by a species of gluten, and being able to assume two forms,
the one linear and the other lamellated. ‘This fibre was
the base of the cellular texture, which they regarded as
the substratum of all the solids of the human body. But
this elementary fibre has never been seen, and moreover,
there are textures which we cannot reduce by decompo-
sition to the simple cellular substratum.

An opinion more conformable to nature is that which
recognizes in the organization three distinct elements,
the cellular, nervous and muscular fibre. Very striking
differences characterize these three primitive textures, and
do not permit them to be confounded, Ist. In relation
to the form ; the cellular fibre is composed of fine lamine
and delicate filaments, white and extensible; the nervous,
of a soft substance nearly fluid, contained in a cellular
envelope ; the muscular, of round filaments, soft, pulpy,
greyish or red. 2d. In relation to the chemical nature ;
one is resolved into almost pure gelatine when it is treated
with boiling water ; the other is essentially formed by
albumen united to a fat substance, and the third by fibrin.
3d. In relation to the vital properties ; those of the cel-
lular fibre are obscure and are confined to the latent sen-
sibility and the invisible contraction known under the
name of insensible organic contractility, whilst. the
nervous has, besides the faculty of transmitting the im-
pressions to the mind, senszbility properly so called ; the
muscular on the contrary, is distinguished by the irrita-
bility which it possesses.

All the organized textures have for their base one of
‘these three primitive fibres, or result from the union of
many of them; thus the cellular element is found in most
of the organic systems; it constitutes almost alone the

GENERAL OBSERVATIONS. 19

cellular texture, the serous membranes, the dermis of the
skin and of the mucous membranes, the parietes of the
sanguiferous and lymphatic vessels, and the fibrous or-
gans; thus the muscular system is formed by the assem-
blage of the muscular and cellular elements, &c.

This division of the primitive textures, pointed out
by Haller and Blumenbach, has been followed by most
modern anatomists. Some have modified it by adding
to them a fourth element, the fibrous texture. It is to
this new fibre that M. Chaussier has given the name of
albugineous fibre. ‘The characters which he gives to it
are a white colour, shining like satin, and a considerable
density ; boiling water converts it in great part to gela-
tine ; it is but slightly extensible and very resisting ; its
vital properties are hardly perceptible; it is this which
forms the fibrous or albugineous membranes, the tendons,
aponeuroses and ligaments. ‘These characters resemble

very much those of the cellular fibre, from which the albu-
_ -ginea seems to differ only in the greater approximation of
the particles, which is the reason of the greater tenacity
it possesses. We can even refer to a modification of the
cellular fibre the elastic, yellowish texture, which consti-
tutes the middle texture of the arteries, the yellow liga-
ments of the vertebre, the posterior cervical ligament of
animals, &c. and which is distinguished by its colour and
its elasticity from the common or albugineous fibrous tex-
ture of M. Chaussier. Nothing proves more the great
affinity which naturally approximates the cellular fibre and
these two species of fibrous textures, than the facility with
which they are transformed into cellular texture, when
they disappear preternaturally.

If we consider the organized elements under another
point of view, we see that it is possible to bring by the
analytical method the different textures of the animal

20 ADDITIONS TO THE

economy to a certain number of primitive forms, which
are inseparable elements of all organization. This obser-
vation has ,occasioned many classifications of forms or
elementary textures. The first and most simple is that
which admits but two of them; Ist, the fibrous form ;
2d, the lameliated form, a division already established
by the ancients. A greater extent in length characterizes
the fibre ; the lamina has dimensions nearly equal in
length and breadth, but little thickness. The fibres and
the laminz can by their interlacing leave between them
spaces variously formed, called cel/s. The fibrous struc-
ture predominates ; it is evident in the nerves, the mus-
cles, the bones, and the fibrous textures; some organs
exhibit at the same time a fibrous and lamellated tex-
ture.

Others recognise a gpltiese number of elementary forms
and add to the two preceding ones the globular and the
granulated form; the first belongs especially to the
fluids ; the second is observed in the glandular texture.
They admit besides as secondary forms, Ist, the cellular ;
2d, the vascular ; 3d, the solid, as that of the cartilages,
the bones, &c. |

Other divisions also exist which appear to be founded
at the same time upon the forms and upon the nature of
the textures. It is thus that Walter establishes, Ist, a
_ cellular or membranous texture ; 2d, a vascular or fibrous
one ; 3d, a. nervous one. So we find in the classification
of Dumas, Ist, the cellular or spongy texture; 2d, the
muscular or fibrous texture ; 3d, the mixed or parenchy-
matous texture; 4th, the lamellated or osseous texture.
These divisions are by no means preferable ; they are in-
sufficient if they represent the secondary textures or
organic systems, and too multiplied if they only ‘Keita
the primitive elementary forms.

GENERAL OBSERVATIONS. 21

Nol dhetatiding the delicacy of microscopic researches
and the deceptions so difficult to be avoided in this kind
of experiments, the labours of Hewson, Prochaska, Wen-
zel and other observers, have served for the basis of a
theory of the organized elements which differs considera-

bly from the other opinions upon this subject, and which
has been particularly developed latterly by J. F. Meckel.

According to this anatomist, the solids and the fluids of
the human body can be reduced, in the last analysis, to
two elementary substances, one formed by globules, the
other by a coagulable matter, which, either alone or united
to the first, constitutes the living solids, if it be in a liquid
state, and gives origin to the solid textures, if it be in a
concrete state. *

The globules exhibit, in their appearance and even in
their nature, differences which are especially relative to
the places in which they are examined. In the blood,
they appear flat and composed of a central part which is
solid, and of an external part which is hollow and vesi-
cular. Those of the kidneys are smaller than those of
the spleen; the globules of the liver are still more deli-
cate. The globules contained in the substance of the
nerves exhibit a less size than those of the blood; it is
the same in the lymph, the milk and the chyle. Certain
fluids, as the urine, do not contain globules. Many solids
are entirely destitute of them ; such are the cellular tex-
ture, the fibrous parts, the cartilages and the bones. They
abound on the contrary in the blood, the nerves and the
muscles. They form the essential part of the textures,
the colour and nature of which they determine.

These globules appear to undergo modifications accord-
ing to age; but direct experiments are wanting on this
point. _Hewson says he has found in birds and reptiles,
the globules of the blood of a different form and size in

22 ADDITIONS TO THE

the embryo and the adult animal. In the first p
after conception, the mucous and homogeneous mass which
constitutes the embryo does not contain globules; it is
not till a more advanced period that it is composed of two
substances, one fluid and the other solid, every where
immersed in the first. The globules are then very appax
rent, more distinct than they will be afterwards ; they are
seen in all parts of the embryo. ’

These two elements, the globules and the coagulable
fluid, may assume the form of fibres or lamine. The
lamellated form belongs almost exclusively to the fluid
matter. The fibres may be formed by this substance only,
as we see in the bones, the tendons, &c.; they are the
effect most often of the union of the globules and the con-
erete fluid, of which the nervous and muscular systems
exhibit examples.

These considerations of Meckel upon the organization
of animals have some relation with the division of the
organized elements established by Pfaff, which admits as
primitive elements fibres and cells, themselves formed of
a series of particles or globules. They differ from it in
this that we find in it, besides the solid globules, the idea
of a concrete fluid substance, analogous to that which the
ancients designated by the name of gluten. It is accord-
ing to Meckel the cellular texture which represents this
substance ; it regards in fact this texture as a sort of con-
crete fluid, as we shall see in the article on the cellular
system.

Classification of Morbid Anatomy.

Page 59.—“ This course (of classing the alterations
according to the systems to which they belong) is incon-
testably the most natural, though, as in all divisions in

GENERAL OBSERVATIONS. 23

which we wish to subject nature to our views, there are
many cases which it almost excludes,”’

The recent progress of morbid anatomy has occasioned
new classifications which, without being entirely exempt
from the inconvenience of constrained approximations,
nevertheless contain, useful divisions founded upon natural
relations established between the various organic altera-
tions. Bayle, Laennec, Cruyeilhier, J. F. Meckel, &c.
have been particularly engaged in this subject. |

ist. Having seen that the alterations of texture have
nearly the same characters, whatever may be the tex-
ture they affect, they have found the greatest advantage
in uniting them into one and the same class, so that
they avoid the numberless repetitions which an opposite
method produces; they exhibit at the same time and
under the same point of view, analogous objects, and no-
thing is more proper, as we know, to hasten the progress
of any science.

2d. The same method has ins applied, though with
less success, to the derangements that affect only ‘466 ex-
ternal forms.. Itis searcely any where but/in the original
defects of conformation that a methodical order can be
followed or that it is attended with any real utility. The
preternatural derangements of form have too little resem-
blance, to make it advantageous to approximate them.
Thus it has been proposed to preserve here the anatomi-
cal order adopted by Bonet, Morgagni and in part by
Bichat, till the science shall be sufliciently advanced to
substitute another for it.

They have followed the same principles, as much as
possible in the subdivisions. The most natural and
numerous is that of the transformations or organic pro-
ductions, which the class of the alterations of texture em-

94 ADDITIONS TO THE

braces. They are characterized by the preternatural
development of a new texture in the part which is the
seat of them. They are divided, according as this texture
has some analogy in the economy or is wholly foreign to
it, into organic transformations properly so called, and
into degenerations or preternatural textures which only
exist in a state of disease. = =>

J. F. Meckel is hitherto the only one who has made
an application of these data to a complete system of
morbid anatomy. The following is the order which
he has pursued in a very extensive treatise that he has
published in Germany on this subject :

He admits the two great divisions of which we have
spoken, viz. the alterations of form and those of texture.
Among the first are found arranged, 1st, the original de-
fects of conformation, subdivided according as they af-
fect the number or nature of the parts, into defects of
guantity and defects of quality ; 2d, acquired derange-
ments of size, situation, configuration, &c. which com-
prehends luxations, hernias, solutions of continuity, con-
tractions, dilatations, atrophies, &c.

The alterations of texture are confined to two principal
heads. Some change only the physical properties of the
affected texture, such as the colour and density. The
others completely change its organization. These being
often the product of inflammation, this affection is naturally
placed here. The manner of the separation of the injured
organs is described at the same time. Finally come the
transformations and degenerations properly so called.
The author still ranks among the preternatural produc-
tions worms and concretions.

GENERAL OBSERVATIONS. 25

We shall adopt the following order in the exposition of
the morbid alterations of each system.

a

Situation. +
pat ; ypertrophy.
ist. Alterations in the exter-. auth ; Atrophy.
nal forms | Density.
ee _ (Configuration.
_{ Inflammation.
; Site : . Wounds.
2d. Alterations in the or- Mechanical Lesion Foreign Bodies.
ganization by Transformation, *
Degeneration.

3d. Alterations in the development ; deni mel pai

Preternatural Development.

'

ADDITIONS
TO THE

CELLULAR SYSTEM.

—_————

Adipose Texture.

Page 128.—‘‘ We shall see also, that the fat is sepa-
rated by an exhalation analogous to that of all the other
exhaled fluids, that is to say, by vessels of a particular
order, which are intermediate between the extremities of
the arteries and the cellular texture. We can apply to
the exhalants of fat, what will be said upon the exhalant
system in general.”

The fat does not appear to be simply deposited in the
‘ small spaces of the cellular texture; it has a texture which
is peculiar to it and which contains the oily fluid of which
it is formed. The existence of the adipose texture, which
was imperfectly known to Malpighi, distinctly pointed
out by A. de Bergen and Morgagni, has been particularly
demonstrated by W. Hunter. It has been described in
turns under the names of cellular texture, by calling our
cellular texture filamentous, of fatty texture or pan-
nicle, of adipose membrane or network, of adipose,
funics or vesicles, &c.

28 _ ADDITIONS TO THE

The general arrangement of the adipose texture already
exhibits many peculiarities which cannot arise from the
fat; this fluid cannot of itself have a determinate form,
and nothing is more variable than the external confor-
mation of the fatty texture. In one place it is a mem-
branous layer more or less thick, analogous to that which
exists under the skin, in which it constitutes the fatty
pannicle. In another it is in irregular masses, such as
are found around the kidneys, in the orbits and the thick
part of the cheeks. In other places the adipose texture
_ exhibits the appearance of pyriform elongations, pedicu-
lated, such as are seen in the appendices of the omentum,
around the arteries which go to the peritoneum, in the
openings of the umbilicus and the. infra-pubien rings,
&c.; in the omentum it forms flattened ribbons or kinds
of network which follow the course of the blood-vessels.
Accumulated in some parts, it appears under the form of
tumours more or less large and prominent, examples of
which are seen in the eminences upon the nates of Hotten-
tot women, in those on the backs of dromedaries, camels,
the bos urus, and the tail of the Barbary sheep.

The adipose texture, considered in its external organi-
zation, is not less distinct from the fat which it contains.
Whatever may be the different forms it assumes, its struc-
ture is every where the same. It is divided into rounded
bunches, separated from each other by grooves more or
‘less deep, of a form irregularly oval, and of a diameter
varying from aline to half an inch their size differs also
according to the degree of corpulency and according to
the part examined. Each of them is composed of smaller
particles, which are easily separated by dissection. These
are spheroidal, miliary, compressed, similar in form to the
seeds of the grape or still more to the vesicular granula-
tions which constitute the inside of oranges, and other

CELLULAR SYSTEM. 39

fruits of the family of hesperides ; we discover, by the
aid of the microscope that they are themselves a collec-
tion of united vesicles, exhibiting precisely the same ap-
pearance, except as to size, since according to Monro,
their diameter is from the eight hundredth to-the six
hundredth of an inch. According to Wolff these vesicles
may have a different size in different species of animals.
They do not appéar to communicate with each other;
their parietes are delicate and transparent, which has
made Monro and Clopton-Havers who have observed
_ them in the marrow of the bones, compare them to col-
lections of small. pearls.. They contain the fatty fluid, the
yellowish colour of which is visible. |

The adipose texture is provided with a vascular appa-
ratus, which has been very well described and drawn by
Mascagni. Arterial and venous branches are lodged in
the grooves which separate the fatty particles; their divi-
sions represent, by their anastomoses, capillary networks
which run along the interstices of the small masses or
particles of which they are composed ; each of these par-
ticles receives a little artery and a little vein which form
for it a sort of vascular pedicle; the microscopic vesicle:
themselves are penetrated by the most delicate ramifica-
tions, which follow at first their interstices, form for them
also a kind of pedicle and finally terminate in their
parietes. This collection of vessels and agglomerated
grains has some resemblance to a bunch of grapes sus-
pended by its peduncle, and in which each of the grains
that compose it, has besides its own pedicle. This
arrangement is easily seen upon a portion of fat taken
from an injected body, or still better from a part naturally
infiltrated with blood.

A very delicate cellular texture seems to exist between
the vesicles and around them ; this texture becomes more

30 ADDITIONS TO THE

apparent in the interstices of the particles visible to the
naked eye, which it connects together ; the little bunches
that arise from them are united by a firmer texture almost
fibrous in some parts, evidently ligamentous in the palms
of the hands, on the soles of the feet, &c.

The fatty texture no doubt contains absorbent vessels,
but we are ignorant of their arrangement. . It is the same
with regard to the nerves. Its intimate nature appears
to resemble very much that of the cellular texture. It is
in fact a soft substance, whitish, extensible, contracting
when distension is removed, appearing under the form of
fine and semi-transparent, lamin and having the greatest
analogy with the lamellated or cellular fibre... If the fat,
which it contains, disappears. preternaturally, the vesicles
flatten and are confounded with the surrounding cellular
texture, without leaving any trace of their existence.
Hunter says, nevertheless, that in these cases the cellular
texture differs in some of its properties from that which
never contained adipose vesicles, and he attributes these
differences to the presence of the empty vesicles which
the first contains.

It would be wrong to conclude from the resemblance
that is found between the fatty and cellular textures that
they are precisely the same. It is easy to-point out the
characters which distinguish them. 1st. The adipose
vesicles are shut on all sides, and their substance is not
permeable to the fluids which tend to penetrate it, very
different in this from the areolar substance of the lamel-
lated texture. This is proved by many facts. Take a
piece of adipose texture, raise its temperature gradually
by means of warm water, until it is sufficient to melt the
fat without altering the structure of the vesicles, the oily
matter will remain contained in them without flowing
out. . Expose a bunch of fat to the heat of the sun sufli-

‘CELLULAR SYSTEM. 81

cient to raise the centigrade thermometer to + 40 degrees,
you are very certain that at such a temperature the fat
must be perfectly fluid; yet not an atom of it will flow
out; cut some of the vesicles, and the oily fluid will
immediately appear. We obtain also the same result by
compressing between the fingers a fatty mass; the fat
does not escape unless the vesicles are ruptured. In the
most extensive emphysemas, in the greatest serous infil-
trations, the effused fluids never penetrate the vesicles ;
the fat remains distinct and is not mixed with these
fluids. If it were otherwise, should we not see during
life, the fat, fluid at the ordinary temperature of the body,
constantly descending to the lowest places, as takes place
with the serum of dropsical patients, yielding to external
pressure in parts which, such as the feet and the nates,
are continually subjected to it, as is observed also in
cedema? The adipose vesicles do not form, like the
cellular. texture, one continued whole; they are merely
contiguous to each other. This is easily demonstrated by
inspection. ‘It is‘also seen in anasarca; the liquid, which
is poured in the cellular texture that is interposed be-
tween the adipose particles, separates them, and they con-
tinue insulated in the serum that surrounds them. 3d.
There is another character. Wherever cellular texture
is found, there are parts always destitute of the fatty tex-
ture, even in the fattest subjects. Does not this fact seem
to indicate, that'there must be a peculiar organization in
the cellular texture, that fat may be developed in it?
Ath. Finally their uses are very different ; those of the
adipose texture only relate to the fat that is constantly
exhaled in the interior of its vesicles, and constantly
taken up by ‘the absorbent -vessels; the cellular texture
has much more important uses, ‘since it forms a common
link which unites all the parts at the same time that it

32 ADDITIONS TO THE

insulates them, and serves to facilitate their motions and
to maintain the harmony of their functions.

Chemical Nature of the Fat.

Page 128.—‘ I will not treat of the chemical nature
ef fat. This would lead me into details foreign to this
work. Besides, I could add nothing to what modern
chemists have said upon this subject.” |

The recent labours of M. Chevreul upon the fixed oils
and the different species of fat, have given results too satis-
factory not to be mentioned here. The fat, far from be-
ing an immediate principle of animals, as has for a long
time been thought, is composed of two peculiar principles,
non-acid, designated from their poor by the names
of stéarine and élaine.

Stéarine exhibits a solid mass, without colour, almost
inodorous, insipid, soluble in alkohol and preserving the
solid state at the temperature of 38 degrees of the cen-
tigrade thermometer. Elaine on the contrary, is fluid at
a temperature of 17 or 18 degrees ; it is without colour
or yellowish, lighter than water and much more soluble in
alkohol than stéarine. It is by taking advantage of this
last property, that we can separate these two principles.
For this purpose we treat a certain quantity of fat with
boiling alkohol ; as the liquor becomes cold the stéarine
is precipitated, taking with it a little élaine ; the greater
part of the élaine remains in solution with a little stéarine.
The action of cold upon fat, and the continued contact of
this substance with paper that has not been sized, can also
serve to demonstrate the existence of its immediate mate-
rials. In the first case, the stéarine becomes solid, whilst
the élaine preserves its fluidity; in the second, the

CELLULAR SYSTEM. 33

élaine is absorbed by the paper and the stéarine remains
on the surface.

The proportion of the principles of the fat is not the
same in all animals nor im all parts of the same animal,
hence all the varieties of consistence which that of man
‘ exhibits. However, as stéarine is not more solid, even
when pure, at a degree of heat equal to the temperature
of the body, the fat ought at least to be semi-fluid during
life, and this is in fact what is observed in surgical opera-
tions, during which there often flows with the blood some
oily drops coming from the cutaneous adipose vesicles.

Besides the peculiar acid, (the sebacie acid) which is
produced during the distillation of fat, there are two others
that are obtained by treating it properly with an alkali
or some metallic oxyd; one is the margaric acid, so
called from its pearl colour, the other the oleic acid.
Soaps, which result from the action of alkalies upon oils
are nothing but salts formed by these two acids and the
base that is employed. M. Chevreul thinks that some-
thing analogous takes place in the spontaneous deeomposi-
tion of muscular flesh, when it happens without the con-
tact of the air; he considers the fat of dead bodies which
is produced in this way as a kind of soap, which is the
result of the action of the ammonia coming from the de-
composition upon the fat contained in the muscle.

Intimate nature of the Cellular Texture.

Page 131.—* All these vague ideas of concrete juices,
of inorganic glue, of hardened juice, that have been applied
to the cellular texture, haye no solid foundation, and rest
neither upon experiment nor observation, and ought to be

banished from a science in which imagination is nothing
and facts every thing.’?
§

34 ADDITIONS TO THE

The ancients do not appear to have been acquainted
with the cellular texture, at least they do not mention it
in their writings. It is without cause that some have
pretended, that they have found some notions of it in a
passage of Hippocrates, in which the question is respect-
ing the general permeability of the textures. Adrien
Spigel is one of the first who have spoken of it. Vesalius
and others made it known successively in different parts
of the body. It is only since Haller and Bergen that it
has been considered as generally distributed to all the
parts. Bordeu appears to be the first who compared the
cellular texture to a sort of slaver or glue. Quesnay said
that it rather resembled a fluid matter than an organized
solid. Wolff went further; rejecting all idea of cells, he
regarded the cellular texture as a homogeneous substance,
glutinous and. without evident organization. Blumenbach,
Kern. Platner and J. F. Meckel, have adopted this opinion.
This last has made the cellular texture his concrete fluid
element. The following are the observations and facts
upon which these anatomists rely.

Ist. Inspection, say they, does not discover in the cel-
lular system the fibres or layers of which it is supposed to
be formed. Examine it under the skin, between the
muscles, around the arteries, on the exterior of the mem-
branes, every where is found a substance semi-fluid, trans-
parent, tenacious and without any appearance of fibrous
or lamellated structure. If fibres or laminze be developed,
it is owing solely to the means of investigation that are
employed. Thus when we separate from each other two
contiguous organs, which are united by cellular texture,
two muscles, two fasciculi of the same muscle or two
muscular fibres ; when we raise-this texture from the sur-
face of the organs it covers, it yields to the distension, is
elongated and presents the appearance of delicate laminz,

*

CELLULAR SYSTEM. 35

which are changed to round filaments if the distension be
carried further, precisely as if it were a piece of glue or
paste, according to the expression of Bordeu. ‘The dis-
tension having ceased, the parts approximate, and the in-
terposed cellular layer reappears homogeneous and per-
fectly continuous. So when we examine the cellular tex-
ture of the scrotum by stretching it to a kind of membrane,
it is evident that the lamin and the interlaced filaments
that are seen are the product of distension, and this ap-
parent organization is not observed until after having de-
veloped it artificially.

2d. These pretended cells do not exist either in the
mucous texture, which does not exhibit openings on its
surface, as it would if there were these little cavities.
When cavities are found there, it is because foreign bodies
raise it up and give it a vesicular appearance. When, for
example, the cellular texture is drawn in different direc-
tions, it often happens that it is penetrated with air in its
interior. This air then assumes the form of bladders, as
it does in soap suds. But if we press upon these bladders,
they disappear ; and, if we. afterwards reproduce them,
they may be very different from the first. We give them
very various forms, increase or diminish their number,
precisely as in soap suds. Inflation produces also in the
mucous texture a cellular appearance, which is explained
in the same way by its state of softness and semi-fluidity.
The injected air penetrates it easily, and the distension,
which it occasions, produces that appearance of fibres and
interlaced laminze, which has been said to be peculiar to
this texture, whilst it is a form which it possesses but for
a moment. It is the same with regard to the cells ob-
served after congelation ; they are interstices preternat-
urally produced by the presence of a fluid diffused in the
cellular texture. ;

36 ADDITIONS TO THE

$d. Any part of the cellular system exhibits by turns,
fibres, laminz or cells, according to the process employed
to develop in it either one or the other structure. Dis-
tension produces laminz or fibres, according to the extent
to which it is carried; inflation produces cells, &c.

4th. The cellular texture is permeable ; most fluids,
such as air, water, pus and urine traverse it easily and
run over a great extent in its interior; solid bodies even
have penetrated it, and have gone longer or shorter dis-
tances. How can we admit that bodies thus immersed in
the mucous texture follow precisely the direction of the
cells and of their orifices? Is it not rather the medium,
and, as it were, viscid consistence of this texture which
permits it to yield to the effort of the substances which
tend to penetrate it, and accommodate itself at the same
time to the various forms which they imprint upon it?

5th. Finally, they add, that in the foetus of man and in
the lowest classes of animals it is impossible, under any
circumstance, to discover any organization in the cellular
texture ; a mucous and homogeneous mass only is found.

It is for anatomical inspection to pronounce upon the
validity of these objections, which cannot be overthrown
by the single consideration of the phenomena of vitality —
which the cellular texture exhibits in diseases. Would it
be the first example of a texture endowed with life, whose
homogeneous. structure did not allow distinct lamine or
fibres to be seen? Is it not so with the cerebral substance,
the cartilaginous texture and the serous membranes? We
do not seek to know if the texture peculiar to the cellular
system be the seat of an evident vital action ; this point
would not he contested, but only if we should admit that
jt has a fibrous or lamellated organization, or whether this
organization is developed, except under certain influence,
of which it is the immediate result. What is certain is,

€ELLULAR SYSTEM. 37

that it appears under many circumstances as if it were
really spongy or cellular, and there can be no incon-
venience in regarding it as such. |

MORBID ANATOMY OF THE CELLULAR SYSTEM.

I. Alterations in the external forms.

Tue size of the cellular texture can be increased in
consequence of a more copious exhalation of the fluids it
contains. This iswhat happens in anasarca and in obesity
or corpulency. The serum accumulated in anasarca resem-
bles that of dropsies. It runs moreover freely through
the cellular texture, and collects in general in the most
depending parts. The looseness of this texture in some
regions disposes it also to infiltration. In old oedemas, the
cellular texture sometimes acquires a very great thick-
ness; it seems as if there were made an exudation of a
fluid capable of concretion which increases its density by
adding to the laminze which compose it.

Obesity or the accumulation of fat is general or local;
the first has been examined under the article upon the
cellular fat.

Fatty tumours, which constitute the second, are of very
various forms ; their size is sometimes very considerable ;
frequently they are provided with a pedicle through which
the vessels enter. A cellular coat invests them on the
exterior; their structure is that of the adipose texture.
The vesicles appear to be more numerous than in a state
of health, for Monro has obseryed that their diameter is

38 ADDITIONS TO THE

the same. These tumours are especially developed in
parts which contain much fat; henee the Goqmany< of
wens or sub-cutaneous fatty sinner’

Besides the fluids naturally contained in the cellular
texture, air can also accumulate in it, which constitutes
emphysema. This last is more or less extended. It is
sometimes developed after denth, in apoplexy, urinous
effusions, &c.

An increase of size and density at the same time
appears to constitute the disease described under the name
of hardening of the cellular texture... There is only found
in it in facta greater thickness and consistence of this
texture, which scarcely yields to the pressure of the
finger; there is usually joined with it a more or less
considerable serous infiltration. This affection is, as we
know, almost exclusively confined to new born infants.
It is below the skin that it most commonly appears; it
has also been seen in the inter-muscular cellular texture.

The elephantiasis or disease of Barbadoes is owing to
an alteration, of the same kind.

II. Alterations in the organization.

Inflammation of the cellular texture is very frequent ;
there are many varieties of it, particularly according to
the part it attacks.

In acute inflammation, in phlegmon properly so called,
the cellular texture is of amore or less bright red, as if
infiltrated with blood; the serum disappears, the small
spaces being obstructed are much less permeable than in
the natural state ; they are afterwards filled with a concrete
albuminous matter, which resembles a kind of jelly. The
ulterior phenomena differ according to the mode of termi-
nation. In the most common cases, suppuration takes

CELLULAR SYSTEM. 39

place, the pus hollows out a cavity which is continually
enlarging, and an abscess is formed ; or there is an ab-
sorption of the effused albuminous matter, and consequent
resolution. At other times this matter seems to become
organized at the same time that its consistence increases 5
it is insensibly confounded with the organ which furnishes
it; this is what is observed in the termination by indura-
tion. In gangrene, the mortified cellular texture produces
soft eschars, of a whitish or grayish colour; it is reduced
to.a sort of putridity.

Chronic inflammation especially produces induration; a as

we see in old ulcers. We frequently find as its conse-
quence that sort of brittleness of which Bichat speaks
(page 142). In some cases the inflammation is accompa-
nied with ulceration and dgnreetion of the cellular tex-
ture.
The cellular texture, when viscid divided by a shines
ical lesion, unites quickly, if the divided edges be in con-
tact ; this is what takes place in the closing of abscesses,
in the union of wounds by the first intention, &c. The
adhesion is. established by means of a coagulable fluid
which is effused, becomes concrete and organized, so as to
form a new texture for some time more dense than the
surrounding cellular wap with which it finally becomes
confounded.

The cellular texture, laid bare by a solution ‘of con-
tinuity with a loss of substance, exhibits all the phenom-
ena described in the formation of fleshy granulations and
of cicatrization.. Vanhoorn, has seen in amputations the
fatty cellular texture disappear at first from the surface
of the wound, to be afterwards replaced by a new texture,
more dense and resisting than the first. |

Foreign bodies introduced into the cellular texture pro-
duce there a more or less severe inflammation ; the suppu-

40 ADDITIONS TO THE

ration which results from. it brings them gradually to the
exterior, so that if they be deeply situated, they thus go a
considerable distance. We see this texture then approxi-
mating, constantly uniting behind the foreign body, whilst
it suppurates and opens before it. This peculiar course
of the inflammation has — it the name of the expul-
sory inflammation.

In some cases however, foreign bodies remain in the
cellular texture without producing any inconvenience
there ; there is formed around them a kind of membrane,
a cyst, which keeps the neighbouring parts from their
contact; this is what takes place in some sanguineous
effusions, when the presence of the coagulum does not
occasion the formation of an abscess. The sac, which
contains the blood in false aneurisms, is produced by an
analogous mechanism.

‘Besides inanimate bodies, solid, fluid or gaseous, which
preternaturally enter the cellular texture, we find there
real animate bodies, worms. The cysticercus cellulose,
the filaria medinensis or hair snake properly called, and
the larve of .the oestrws have been met with by different
observers, not only below the skin, but in the inter-
stices of the muscles, in the ii of the pia ‘mater,
and even upon the bones.

Various natural textures of the economy are preter-
naturally developed in the cellular system.

Osseous and cartilaginous transformations and produc-
tions are not rare in it; they are observed particularly
in the cellular texture which exists in the neighbourhood
of the serous and synovial membranes, sometimes even in
that which penetrates the substance of the organs, and
less frequently in the sub-cutaneous cellular texture.
The fibrous texture frequently appears also in the lamel-
lated texture; we find examples of it in the parietes of

CELLULAR SYSTEM. | 41

certain cysts, in the production of fibrous tumours, &c.
It is to the transformation of this texture into serous
membrane that must be referred the production of most
cysts, which are developed at its expense. Motion also
produces in some places preternatural serous membranes.
(Vide Serous System.) Abscesses and old fistulas are
lined by a membrane which has some analogy with those
of the mucous system. © A

All these various forms, which the cellular texture can
assume, ought not to surprise us, when we recollect that
the fibre which constitutes it makes at the same time the
base of most of the organic systems.

Degenerations, properly so called, are very common in
the cellular texture; the more abundantly an organ is
provided with it, the more is it exposed to this kind of
affections. But they do not only attack this texture,
when it is found combined in the different organs with
' the other elements of which they are composed, but the
loose cellular texture that surrounds them is equally sub
ject to them; that even, which, being accumulated in
certain regions, seems entirely insulated there, is not
exempt from them. Thus in the white swellings of the
articulations, in the cancerous affections of the glands and
of the viscera, the lamellated texture is almost always con-
founded with the diseased parts which it covers and is
degenerated like them. Thus we find, in the places
where the cellular texture is accumulated, schirrous, car-
cinomatous, tubercular and fungous masses, in which this
texture alone appears to be altered.

Ill. Alterations in the Development.

The cellular texture can itself be developed preter-

naturally ; it is met with in a ‘great number of morbid
6

42 ADDITIONS TO; THE CELLULAR SYSTEM.

productions ; many.of them are essentially formed of it.
This texture takes the place of atrophous organs; it is
produced on the surface of suppurating wounds, in- which
it constitutes the membrane of the fleshy granulations.
The mechanism of its formation under these circum-
stances is far from being perfectly understood, to say that
it is an extension, an elongation of the cellular texture
which pre-existed in the part, is not explaining how this
sort of exuberance, is developed. Every thing leads us
to believe that it is a new texture formed, as in the
union of simple wounds, by means of an exudation of an
albuminous nature or at least of one capable of concre-
tion. What is observed in fact in a solution of continuity
which is cured by cicatrization ? The hemorrhage ceases,
the blood is replaced by a serous fluid, the wound is
covered by a soft whitish layer, at first feebly adhering
to it; soon this substance, to appearance inorganic, is
penetrated with vessels, becomes more dense, it cannot
be separated but with difficulty from the subjacent parts
and it takes all the characters of the membrane of the
fleshy granulations. Has not this series of phenomena
the greatest analogy with what takes place on the surface
of inflamed serous membranes? Do we not see in both
cases an effusion of lymph capable of concretion, the re-
sult of which is the production of a false membrane,
which, by becoming organized, is changed into real cel-
lular texture ? 3

TO THE

NERVOUS SYSTEM OF ANIMAL LIFE.

fp —..-]
Nerves which the Brain furnishes.

Page 172.—“ The cerebrum furnishes but two nerves,
the olfactory and optic; ......... their softness is greater
than that of most of the other nerves,”

The optic nerve is placed at the present day, among
those of the medulla oblongata. It derives its origin in
fact from the tubercles which surmount the posterior part
of the tuber annulare; tubercles called guadrigemina in
man, though there are but two of them in many animals,
and the size of which is such, in many classes, as birds
and fishes, that they might be taken for cerebral hemis-
pheres. These tubercles which deserve to be called optie
rather than the thalami to which this name has been
given, are evidently a dependance of the cerebral protu-
berance, and not of the cerebrum, as some anatomists
have said. As to the olfactory nerve, its origin is not

44 : ADDITIONS TO THE

yet well known. Animals exhibit it to us coming out of
an accessory part which their cerebrum has, from a kind
of lobe superadded to its hemispheres. This lobe, some-
times more considerable than all the rest of the cerebrum,
is formed by an elongation of the peduncles which extends
forwards. But nothing similar appears to exist in man.
The olfactory seems to be detached from the surface of
the brain itself. Yet some anatomists say that they have
traced it further.. M. Chaussier makes it arise from the
corpus striatum, and others have seen it continued with
the peduncles. In this last hypothesis, and by reasoning
from analogy, some consider the pulpy swelling of this
nerve as its real point of origin. This swelling would
form part of the cerebrum and represent the olfactory
lobe of animals; the nerves of this name would only com-
mence at the ethmoidal canal. :

Origin of the Nerves.

. ‘Page 173.—“ It is clear, that the nerves do not arise
deep in the cerebral substance, at least in an apparent
manner, but take their origin from its external surface.”’

Aceurate researches have demonstrated, Ist, that we
can trace, to a certain depth, the filaments of the origin of
most of the nerves both spinal and cerebral; 2d, that
these nerves do not arise from the medullary substance,
which they only pass through, but from the grey substance,
which is always found accumulated in the neighbourhood
of the places where they are sent off, as Vicq-d’Azyr has
already remarked. These truths have been placed be-
yond'a doubt by the recent labours of M. Gall.

The mass, of grey substance which occupies the centre
of the spinal marrow forms there on each side, when the

NERVOUS SYSTEM OF ANIMAL LIFE. 45

marrow is cut across, two arched striz. From the median
line, where these striz are united, they go obliquely out-
wards, one before and the other behind, and are evidently
continued with the anterior and posterior branches of the
spinal nerves. In other words, this grey substance repre-
sents in the marrow two species of prismatic cords united
atthe back by one of their angles, and continuing with
the nerves by the other two.

In examining attentively the cerebral nerves at their
origin, we perceive moreover more or less distinctly the
grey substance which furnishes them. Sometimes this
substance is superficial, as at the origin of the olfactory and
eptic nerves, and nothing is more easy than to see the me-
dullary filaments separating from it. Sometimes it is
deeply situated, and it is only by a careful dissection that
we can discover the true origin of the nervous fibres,
which, breaking off on a level with the cerebral substance,
seem to arise from this place. Sometimes the nerve is
strengthened in its course by the addition of new fila-
ments which come to it from the neighbouring parts of
the cerebral substance; this is the case with the optic.
There exists also some of the grey substance at the origin
of these filaments.

Nevertheless we ought not to conclude from these facts
that the grey substance produces the nervous filaments,
and it is no doubt in a figurative sense that M. Gall: has
ealled it the originating, or nourishing substance, or
matriz of the nerves. The word origin, as Bichat has |
observed, must not be understood literally. Besides, be-,
cause the grey substance is met with wherever the ner+
vous is continued with the nervous centres, it does not
follow from that, that one is made by the other; the

union of these two substances may have very different
uses, 3 Re |

46 ADDITIONS TO THE

Crossing of the Nerves.

Page 174.—‘ I do not believe that with our present
knowledge we can explain this phenomenon” (the crossing,
in paralysis from compression of the brain,) “ and the
anatomical opinion pointed out above”’ (viz. that the nerves
eross at their origin) “ is contradicted at the first sight.’’

If in fact the crossing of the nerves at their origin has
been rather supposed than seen, it is not so with that of
the spinal marrow which Petit, Lieutaud, Winslow and
other anatomists have admitted. Raise carefully the pia
mater which covers the extremity of the medulla ob-
longata, afterwards separate the anterior pyramidal emi-
nences, and you will distinctly see the medullary fila-
ments of the right side going to the left, directed ob-
liquely towards the cerebrum; and vice versa, those
which compose the left pyramid ascend and go to the
right side. Above this crossing in the form of a mat,
the pyramids are united by transverse fibres, which
should not be confounded with the oblique ones here re-~
ferred to. :

This arrangement enables us to explain how the lesions
which exist above this place, either in the cerebrum or
the medulla oblongata, produce paralysis in the side op-
posite to the affected one. On the contrary, when the
spinal marrow is divided transversely and. on one side
only, the same side is paralyzed, as Yelloly has proved ;
Galen had before noticed this fact.

It has been ‘said that in some cases, paralysis and the
cerebral injury which was the cause of it, have been seen
to occupy the same side of the body, the motions being
preserved on the opposite side. It is hardly possible te

NERVOUS SYSTEM OF ANIMAL LIFE. AT

explain these insulated facts, at least to admit the explana-
tion which M. Gall has given. This explanation is found-
ed upon this, that among the fasciculi which go from the
spinal marrow to the cerebrum, the anterior pyramids
alone cross. Now, by supposing that the cerebrum
should be injured in a point where its fibres are not con-
tinued with those of the pyramids, the phenomenon
arising from the crossing will not take place. It would
remain to be known if this exception is met with in the
cases observed ; this has not been stated.

=

Chemical Composition of the Nervous System.

Page 196.—< This hardening, the effect of acids, of
boiling and of alkohol......... approximates this substance”’
(the cerebral) ‘‘ to the albuminous fluids. I say that it
approximates it, for there are still great differences be-
tween them, of which, I think, we know but little.”

The cerebral substance has been analyzed by modern
chemists. M. Vauquelin has found in it, 1st, two pecu-
liar fat substances united to a certain quantity of phos-
phorus; 2d, water which forms 0,80 parts of it; 3d, albu-
men; 4th, osmazone; 5th, sulphur; 6th, phosphate of
potash, lime and magnesia; 7th, some appearances of the
muriate of soda. |

Of the two fat substances, one is white, shining and of
a soft and viscid consistence. It is distinguished from
fat, properly so called, by its crystalline appearance, by
the facility with which alkohol dissolves it and by the
black colour it assumes when heated. When burnt, a
charcoal is left for a residuum which contains phosphorie
acid. It constitutes 0,45 of the substance of the cere-
brum. The other fat substance is much less abundant in »

4S ADDITIONS TO THE

it, and differs from the preceding only in having a red
colour, a strong odour and taste and being still more
soluble in alkohol.

(he same principles are found in ‘ive spinal marrow ;
the! proportion of fat substance is greater in it; there is,
on the contrary, less albumen, osmazone and water. The
ae oblongata exhibits the same differences.

is the albumen which predominates in the nerves ;
the white and red fat substances are in very small quan-
tity in them.

| Peculiar Texture of the Nervous System.

as 199.—** In general I think that this substance,”
nervous) “as well as the cerebral, would be ranked,

: they were deprived of the vessels that run through

them, rather among the fluids than the solids, or they
would form a medium of connexion between the two.’?

e ought to distinguish in the texture peculiar to the
organization of the nervous system, the two substances
which it contains, the white and the grey.

i white or medullary substance is evidently com-
posed of fibres in many parts of the cerebrum ; such as
the corpus striatum, the corpus callosum, the tuber annu-
lare, the elongations which it sends to the cerebrum and
to the cerebellum and the termination of the medulla
oblongata. Except this small number of exceptions, the
cerebral mass, when’ cut in all directions, seems to be
perfectly homogeneous, and is uniform in appearance ex-
cept from the red points which are the orifices of the
divided vessels: there is no very distinct filament seen
in it. Yet we shall be compelled to admit the existence
of filaments, for, if we endeavour to tear the white sub-

P
VA j
NERVOUS SYSTEM OF ANIMAL LIFE. 49

stance, we shall see that it resists more in one direction
than another. But if instead of thus dissecting the cere-
brum by cutting it irregularly, we attempt to trace the
course of the apparent fibres to its inferior part, by gently
scraping the cerebral substance in the direction of these
fibres, we shal! soon acknowledge that they extend much
further than we at first thought. We shall see them
penetrating the cerebral mass itself, becoming stronger
there and contributing by their union to form those emi-
nences that are so numerous, those fasciculi so variously
formed, between which we do not at tgs find any kind
of connexion.

It was by pursuing this method that Malpighi discover-
ed the real structure of the cerebrum, so well developed —
since by Reil, M. Chaussier and M. Gall. Nothing is
easier than to verify the facts stated by these anatomists,
provided we could have a brain of a certain consistence,
such as would be that of a living animal. We can ren-
der it firmer by the means of reagents. We cannot
say that it is their action which produces'an appearance
of fibres, for with very dissimilar liquids, the results
are uniform. The following is the arrangement whiclr is
observed :

The fibrous fasciculi which constitute the termination
of the medulla oblongata, having arrived at the inferior
edge of the tuber annulare, separate. The posterior bo-
dies go to the cerebellum in which they terminate. The
anterior pyramidalia and the cords coming from the cor-
pora olivaria, traverse the tuber annulare by passing above
its transverse fibres. They plunge into the grey sub-
stance which they there meet with, then come out in
front of the pons varolii, and are extended on each side,
to form the peduncles or crura of the cerebrum ; the me-
dullary filaments are very distinct in these. elongations,

<

50 | ADDITIONS TO THE

because they are mixed with the grey substance which
insulates them. These filaments become larger, when
they are extended across the optic thalami and the cor-
pora striata. Beyond these eminences, the fasciculi
which come from the medulla oblongata spread out in
each of the cerebral hemispheres; their fibres go in all
directions and extend even to the circumference of the
organ. ‘Those which occupy the posterior and superior
part of it come from the corpora olivaria, whilst the
_pyramidalia form especially the anterior and inferior part
of the cerebrum.

On the other hand, the fibres which unite the hemi-
spheres at the median line, as those of the corpus callo-
sum, the fornix and the anterior and posterior commis-—
sures, do not appear to be continued with the fasciculi
coming from the medulla oblongata. Hence the distine-
tion of the diverging and the converging fibres, or appara-
tus of formation and apparatus of union, (Gall) called also
system of the crura of the cerebrum, and system of the
corpus callosum, (Reil.) Anatomists are not agreed re-
specting the origin of the fibres of the second order; per-
haps it differs in each of its parts.

The cerebellum has also two orders of fibres. The
greater part of its mass is derived from those which come
from the corpora posteriora, and which are much increased
in the grey substance of these bodies. Some come from
the fasciculi which the cerebellum receives from the
tubercula quadrigemina; they are those which form more
especially the median lobe, or the superior vermicular
eminence, as Vicq-d’Azyr first demonstrated. | Finally
others, analogous to the commissures of the cerebrum,
unite the two lateral lobes by forming what is called the
Pons Varolii, whether these fibres arise, as M. Gall thinks,
from the external grey substance, or whether they are

NERVOUS SYSTEM OF ANIMAL LIFE. 51

nothing but the diverging fibres curved, as is the opinion
of Tiedemann.

The medullary substance of the nerves is formed, like
that of the cerebrum, of fibres in juxta-position. Accord-
ing to the experiments of Reil, this fibrous appearance is
not owing to the presence of the neurilemas which can
be destroyed with acids without altering the filamentous
texture. L ;

The white substance, examined in ‘the satis marrow
is also composed of filaments ; Vieussens was among the
first who noticed this arrangement, since very well ob-
served by Monro and M. Gall. The arrangement of the
fibres is here very remarkable. The pia mater is buried
in the anterior median furrow, and continued behind into
the substance of the spinal marrow, almost to its posterior
face; from each side of this elongation many grooved
filaments are detached, directed from above below, which
contain the medullary substance. By subjecting the spi-
nal marrow to the action of the alkalies, this substance is
destroyed, and the membranous tubes remain untouched.
There is then a great analogy in this respect, between the
structure of the spinal marrow and that of the nerves ; the
pia mater performs here really the part of the neurilema.
If the consistence of the spinal marrow is increased by
acids, the fibres which compose it are easily distinguished.
Most of them are longitudinal, and represent an infinite
number of small lamina, formed themselves of delicate
filaments; some are transverse. These last are seen
especially in the depth of the anterior median furrow ;
the posterior, on the contrary, exhibits only longitudinal
fibres. All these fibres unite and anastomose in different
ways, as the nerves do.

The grey substance does not form like the white a con-
tinued whole; sometimes exterior to this last, sometimes

52 ADDITIONS TO THE

intermixed with its fibres, it is in general met with,
wherever the medullary filaments become larger. It is
found in the whole circumference of the cerebrum, and
forms what is called the corlical substance ; it composes
at the base of this viscus many masses which have been
compared to ganglions. It occupies the centre of the.
spinal marrow ; it has been said that the nervous extremi-
ties are provided with it, but this has by no means been
demonstrated. 7

The colour of this substance is generally of a brownish
grey, in some parts yellowish and even black; the diver-
sity of these shades is attributed to the greater or less
quantity of blood which it receives. Its density is less
than that of the white substance. Its structure is but
little known; some have admitted that there were fibres
in it; Vieq-d’Azyr has traced filaments coming from the
medullary substance. It contams many blood-vessels,
more even than the white substance ; but it is not entirely
formed of them, as Ruysh thought. His belief arose
from the fact that by washing this substance, after having
injected it, there was finally nothing left but vessels; but
it is evident, that-in this case, as Albinus observes, the
washing takes away every thing that is not vascular or
capable of injection.

The nervous texture, examined by the microscope ap-
pears to be composed of globules ; this has been observed
a great number of times. Prochaska, Wenzel, Barba,
and recently M. Bauer have paid particular attention to
these globules. In order to see them, it is necessary to
mix with water a small quantity of the white substance
and place it in the focus of a strong lens. Their size has
been very differently estimated ; it has been compared, as
well as their appearance, to that of the colourless globules
which are found in the blood. Prochaska thinks them

NERVOUS SYSTEM OF ANIMAL LIFE. 53

smaller than those of the blood. ‘The Messrs. Wenzels
brothers think that they are hollow. They are not de-
stroyed by maceration nor by reagents. Their union ap-
pears to be intimate ; we are ignorant of the mode of it ; it
is supposed that there exists between them a very delicate
cellular texture, containing vessels; others have thought |
that they saw there a fluid and viscid matter. Sometimes
arranged in a row, they form straight parallel lines ; some-
times they are found confusedly heaped together, as Pro-
chaska says he has observed in the grey substance. It is
no doubt from this difference that Carus, rejecting the dis-
tinction of white and grey substance, says that the organ-
ization of the nervous system exhibits but two essential
modifications ; in the one, which constitutes the gangli-
form or central masses, the nervous substance is composed
of irregularly scattered points; in the second, which com-
prehends the nerves, they are regular and constant lines.
From this difference of organization, he deduces the dif-
ferences of action of the two systems, the first being able
to act by irradiation, whilst the other is limited, in this
respect, to the direction of its length.

The colour of the grey substance appears. to reside less
in the globules themselyes,.than in the species of soft
cellular texture which separates~them. To remove the
colouring matter from this substance, it is merely neces-
sary to put it in tepid water in thin slices. Sublimation
produces in part the same effect. This matter does not
then seem to be inherent in the globules.

Development of the Nervous Centres.

Page 237.—“ The extreme softness of the brain ren-
ders its dissection very difficult in the foetus.’’

54 ADDITIONS TO THE

Tiedemann has succeeded in overcoming this difficulty.
This author has traced all the changes of the development
of the encephalon, and has described them with great
precision, Carus, Doellinger and Ackermann, had _pre-
viously stated some facts relative to the development of
the nervous system. M. Serres has recently been en-
gaged in this subject.

The brain scarcely exists in the beginning; in an em-
bryo of six weeks, there is found only a flattened cord
which represents the spinal marrow, and the superior
extremity of which is slightly enlarged.

In pregnancy of two months, the brain is still but very
little developed compared with the spinal marrow; it is
then composed, Ist, of the cerebellum, the transverse ex-
tent of which is considerable ; 2d, of the cerebrum, which
is very small; 3d, of a third portion placed between the
two first, and the size of which exceeds that of the cere-
brum; this part appears to correspond to the cerebral
protuberance, or more exactly to the tubercula quadrige-
mina. M. Serres has ascertained that it is formed in man
and animals, before the cerebrum and cerebellum, and
immediately after the spinal marrow.

The relative dimensions of these organs afterwards
change. The cerebrum grows more and more; towards
the fifth month, it already covers a part of the protuber-
ance ; at the sixth, it extends even upon the cerebellum,
which it gets beyond at the seventh. The other parts on
the contrary increase less in proportion, especially that
which corresponds to the protuberance.

The whole encephalon is divided at first into two parts
by a longitudinal furrow ; this arrangement is observed
in foetuses of seven months. The two halves afterwards
approximate and finally unite, except in some places,
svhere the interstices form cavities ; so that at three months

NERVOUS SYSTEM OF ANIMAL LIFE. 55

we discover instead of a longitudinal division, Ist, the
third ventricle ; 2d, the aqueduct of Sylvius which is, at
this period, a great cavity continuous with the middle
ventricle ; 3d, the fourth ventricle. Afterwards the cavity
of the aqueduct is gradually contracted; it is nothing but
a canal towards the seventh month. The two other cavi- .
ties undergo no ulterior changes but those which belong
to the development of the parietes.

In the first periods of gestation, the conformation of
the cerebrum is very simple; there then exists but the
base of this viscus, and that even is very imperfect. We
see in a foetus of seven weeks only the thalami nervorum
opticorum, the corpora striata are hardly visible ; a sort.
of membranous part seems to indicate the ee of the
hemispheres. .

It is in fact under the form of a membrane that each
hemisphere is developed ; this membrane, originating at
the base is bent before and behind, as it is seen at the
ninth week, and extends to the corpora striata and the
thalami nervorum opticorum ; the space which remains
below them constitutes the lateral ventricles. The an-
terior lobes appear first; they are very visible at three
months. The corpus callosum is formed almost at the
same time, by the junction of the two membranes of the
hemispheres ; it occupies at first only their anterior part,
and is extended backwards as they grow ; at six months
it only extends half their length. The cornua Ammonis
appear with the corpus callosum, as well as the fornix,
the mamillary eminences, the posterior commissure, and
the peduncles of the cerebrum, shortly after is discovered
the hippocampus minor and the groove which gives rise
to it, the pineal gland and its peduncles, then the ante-
rior commissure, the septum lucidum and its cavity, which
then communicates with the third ventricle, between the

56 ADDITIONS TO THE

two pillars of the fornix; in the ‘last place, the semi-
circular band, the plexus choroides and the infundibulum ;
this successive evolution is completed towards the seventh
month. |

All these parts have not the same appearance in the
different periods of their development; thus the fornix
is at first composed of two cords insulated in their whole
extent; thus the corpora striata are for a long time larger
than afterwards and of a different form. At the third
month, the lateral ventricles are open at their internal and
posterior part ; we can, even towards the fourth month,
penetrate into their interior by turning back the mem-
brane which forms them. At the fifth, their extent is
considerable, owing to the small degree of thickness of
their parietes ; they progressively diminish, as these
parietes are developed. ‘The surface of the cerebrum is
smooth in the first months ; soon the fissure of Sylvius is
visible, some inequalities appear, and the circumyolutions
are formed at the seventh or eighth month. |

The cerebellum, in an embryo of seven weeks, appears
like a fine lamina, stretched horizontally from each side
of the fissure which divides the encaphalon at this period,
and continuing on the one hand with the spinal marrow,
and on the other with the cerebral protuberance. This
lamina, bent backwards, forms towards the fourth month
a great cavity continuous with the fourth ventricle ; it
afterwards becomes thicker and the cavity diminishes.
This is redueed to the fourth ventricle towards the fifth
month; transverse furrows then divide the cerebellum
into five lobes. The structure of this viscus is more and
more developed. The lamina are very distinct at the
seventh month. . : |

The cerebral protuberance would be better called in the
beginning the mass of the tubercula quadrigemina ; its

j
NERVOUS SYSTEM OF ANIMAL LIFE. 57

inferior part or Pons Varelii is wanting, there only exists
the lamina which is afterwards surmounted by the tuber-
cula, This part is hollowed out from the aqueduct’ or
cavity of Sylvius, and exhibits a groove which is the
trace of the division which is early observed. The tuber
annulare, properly so called, begins to appear in the course
of the fourth month, but its development is not complete
till the seventh ; it is also at this period -_ that the
tubercula appear.

The spinal marrow forms at first a species of ribbon,
divided by the common fissure and occupies the whole
length of the vertebral canal, extending to the os coccygis.
In the third month, its edges turn over behind and unite,
by which means a canal is formed which is continuous
with the fourth ventricle. At twelve weeks, the termi-
nation of the medulla oblongata is very evident ; we see
there the posterior pyramidalia which are continued with
the cerebellum and the anterior ones making a continua-
tion with the peduncles of the cerebrum. It is at the
third month, according to M. Serres, that the medulla is
contracted and reaches by degrees to the level of the
second lumbar vertebra. At the fifth, we distinguish the
cervical and lumbar enlargements as well as the cauda
equina; the canal of the medulla still evidently commu-
nicates with the fourth ventricle.

Such are the principal changes which take place in the
conformation of the encephalon. Those which it expe-
riences in its texture are not less remarkable.

All is fluid and homogeneous in the beginning. The
white substance afterwards becomes more distinct. Its
fibrous structure is early manifested ; the interlacing of

the pyramidalia is seen at the eighth week, according to

M. Serres. Tiedemann has seen at the fourth month
fibres in these pyramidalia, and shortly after in the fasci-
8

58 ADDITIONS TO THE

culi of the olivaria; these fibres can be traced in the tha-
lami nervorum opticorum and in the corpora striata ; they
extend out in rays to form the membrane of the hemi-
spheres. These diverging fibres become more and more
evident ; ‘at the sixth month, they are almost naked on
the parietes of the lateral ventricles. At the same period,
the cerebral substance has appeared, through the micros-
cope, to be composed of globules immediately below the
pia mater, and of fibres lower down. At the seventh
month, a section of the ventricles exhibits very evident
layers of radiated fibres. New ones are afterwards pro-
duced which form the circumyolutions; they seem to
arise from the external pia mater and are joined at a right
angle to the first ; these are called the converging fibres.
At the ninth month, the organization is completed.
~The grey substance does not appear till a long time
after the white. It is not until from the sixth to the
seventh month that the cords of the corpora olivaria form
real eminences, by the development of this substance in
their interior; the pyramidalia are enlarged a month
sooner. In the last periods of gestation, the canal of the
spinal marrow is also filled with a grey substance ; the
same substance is developed in the circumvolutions of the
cerebrum, in the cerebellum, &c. ; its colour “is not very
evident in all these parts till the ninth month. M. Serres,
as well as Tiedemann, thinks, that the white substance
arises before the grey in the spinal marrow ; but it is not
the same, according to him in regard to the cerebrum ;
he considers the optic thalamus and the corpus striatum ~
as entirely formed of grey substance in the beginning ;
the white is not developed till afterwards. The grey and
white substances are always preceded in their develop-
ment, by that of the red vessels in the places where they
are produced.

NERVOUS SYSTEM OF ANIMAL LIFE. 59

Development of the Nerves.

Page 237.—* The nerves of animal life have a devel-
opment proportional to that of the. brain.”

This relation is very different in the beginning, for we
distinguish the spinal marrow and the brain, whilst most
of the nerves are wanting, on account of the late develop-
ment of the other systems. We know not if it be the
same with the heart and the digestive canal, which are
formed almost as soon as the nervous system. M. Meckel
thinks that the nerves of these organs, like those of the
other parts, do not appear until after the nervous centres.
Yet the great sympathetic appears to exist very early,
and is developed if not sooner, as Ackermann thinks, at
least at the same time’as the brain and spinal marrow.
Another exception to this rule is, that we find, in a month
after conception, the intercostal nerves as well as the ver-
tebral ganglions ; now, neither the brain nor the marrow
are distinct at this period. Perhaps the filaments of the
great sympathetic being more transparent escape. observa-
tion. This nerve is found in fetuses which are born
entirely destitute of all the parts of the encephalon.

In a foetus of three months is seen distinctly the optic
and olfactory nerves. In the following month the fifth
pair is visible. At the seventh, the origin of all the
nerves is seen perfectly well. The olfactory nerves are
at first very large, they begin to diminish at the sixth
month. The spinal nerves are, like the cerebral, very
distinct at their origin before the grey substance is dis-
coverable, (Tiedemann.)

The texture of the nerves does not become apparent,
until their vessels are developed.

60 ‘ADDITIONS TO THE

MORBID ANATOMY OF THE NERVOUS SYSTEM OF ANIMAL
LIFE.

I. Alterations in the External Forms.

Organic diseases often increase the size of the nerves,
as Reimarus has observed with regard to white swellings.
Neuralgias are sometimes accompanied with the same
alterations. Cotugno has found the sciatic, in the neural-
gia of this name, as if it were infiltrated with gelatinous
matter... Fat also may accumulate between the nervous
fibres. A sort of atrophy of the nerves is on the contrary
the result of some paralyses or of pressure too long con-
tinued ; thus in amaurosis, the optic nerve is often har-
dened like horn, and gradually reduced to its neurilema ;
thus various tumours produce atrophy of the nerves which
they compress. The brain appears to have experienced
a diminution of size in the cases stated by Littre and Sa-
batier, in which aftera powerful concussion, this viscus,
they assure us, no longer filled the cavity of the cranium.
_M. Cruveilhier has seen the same thing in the dead body

of an idiot.

The nerves have sometimes appeared to be less con-
sistent than in the natural state. Weinhold, as cited by
Hufeland, has found in them after typhus, a peculiar soft-
ness and flaccidity. They exhibit, it is said, this altera-
tion in dropsies and fatal hemorrhages.

The brain presents the two extremes in relation to its
consistence ; its hardness is seen in mania, idioey and
epilepsy ; its softness, observed at first in the same cir-
cumstances, has been since seen in ataxic and adynamic
fevers and in hydrocephalus. M. Rostan has given some

NERVOUS SYSTEM OF ANIMAL LIFE. 61

new details upon this last alteration and upon the disease —
which results from it. In the eases which he has ob-
served, the softening varies much in relation to its extent,
depth, intensity, colour of the cerebral substance, &c.
M. Lallemand has also described this alteration. |

The spinal marrow loses its consistence in spina-bifida.
Sofiness of the marrow has recently been met with by
M. Scipio Pinel, in cases where it appeared to have pro-
duced peculiar symptoms. Frank has found this organ
hardened. |

Tumours, such as aneurisms, situated upon the course
of the nerves, may displace, distend and flatten them. It
is known how they yield under these circumstances.
Perhaps their elongation may be in great measure attri-
buted to the kind of unfolding which they undergo. The
nerves are in fact folded in the natural state; their sur-
face is, at it were, wrinkled ; by examining it attentively,
we can discover there an innumerable quantity of small
striz, transverse in most, oblique in others, interlaced in
some, forming zig-zags, spirals, &c. These striz are re-
markable fer their yellowish or fawn colour, which forms
a contrast with the pearl white which the nerve preserves
in their interstices. This is at first view so striking, that
we only see at first a multitude of white threads, arranged
precisely like the strie ; the deeper colour of these last
prevents them from fixing the attention so much. Now
these striz are effaced by extension and reappear when it
is taken off. The same thing then should take place in
the cases of which we have spoken.

The brain and spinal marrow are exposed to compres-
sions, which alter more or less their form. The marrow
in particular undergoes at times remarkable bendings;
its functions are not always deranged by them. The form
of the brain also experiences very great changes in hydro-
cephalus.

62 ADDITIONS TO THE

II. Alterations in the Organization.

Inflammation of the nerves is a very rare disease. Can
we give this name to the sanguineous engorgements, vas-
cular dilatations, which their surface exhibits in certain
cases, in typhus, for example? To be certain of the na-
ture of these engorgements, it is necessary to destroy the
neurilema by an acid, and observe what is then the colour
of the medullary substance. Reil, who has followed this
- course in many cases, has found the nervous medulla of
a red colour and evidently inflamed. Suppuration, gan-
grene and ulceration can affect the nerves, but they never
do primarily. The brain, on the contrary, is often the
seat of purulent collections; gangrene sometimes seizes
upon it, as is seen particularly after wounds of the head,
when this viscus is injured or merely laid bare; we re-
move it then by spoonsful, in the form of an extremely
fetid, grey sanies. False membranes are produced in the
brain, especially upon the parietes of the abscesses which
occupy its interior. They are susceptible of being organ-
ized and becoming vascular.

The mode of reunion of the nerves, when they are
divided, has been a subject of discussion. Arnemann has
described it with much care. Shortly after the division,
the superior end swells at its extremity, and forms a kind
of greyish knot, elongated and very hard; the inferior
swells also but less, then both unite and their separation
disappears. The knot continues and often even acquires
a consistence almost cartilaginous. The portion of the
nerve which is below also undergoes some changes,
though all observers are not agreed upon this point. In
general it becomes more slender, is withered, as it were,

NERVOUS SYSTEM OF ANIMAL LIFE. 63

its colour changes and its folds are effaced. As to the
nature of the cicatrix, most authors think it nervous, and as
such, capable of re-establishing the continuity of the nerve
in relation to its functions. Haighton has even made ex-
periments upon this subject, which appear to be decisive.
After having cut in a great number of dogs the two nerves
‘of the eighth pair, either at the same time, or one after
the other, but with only a few days between, and having
- thus ascertained that death was uniformly the consequence,
he allowed in another dog six weeks to elapse between
the section of the two nerves. The animal recovered
perfectly. We may conclude from this, either that the
cicatrix of the first divided nerve transmitted the nervous
influence, or that the functions of this nerve were re-
established between the first and second operation, by
means of anastomoses. ‘lo remove every kind of doubt,
the two reunited nerves were cut a second time in the
same animal and he died. Then it was by means of the
cicatrix that he had lived. Arnemann denies to the cica-
trices of the nerves the property of the nerves ; they are,
according to him, purely cellular, and when the functions
of the nerve are re-established, it is because there is an
immediate reunion between the two ends; but when
these ends are separated, or there is a loss of substance,
‘he denies that a regeneration can take place. The knot —
which is produced appears to him to be incapable of re-
placing the nervous substance; he has seen it arise from
the cellular texture and only gradually unite with the two
ends of the nerve. Yet Fontana, Michaélis and Mayer
say, that they have traced nervous filaments through the
regenerated portion. These filaments are evidently con-
tinued with the nerve. Treated with nitric acid, far
from being destroyed by it, they are hardened, like the
medullary substance under similar circumstances, ( Mayer.)

64 3 ADDITIONS TO THE

Now these physiologists have removed one, two, six
lines, and even an inch of the length of the nerve.

In amputations, the superior end, which forms part of
the stump, swells as in the preceding case. M. Lobstein
has given new details upon this fact, which had been ob-
served by Vanhoorn.

Lesions of the brain appear, like those of the nerves,
to be followed by a sort of regeneration. Solutions of
continuity of another kind have, moreover, their seat in
this viscus. These are the internal lacerations, in conse-
quence of which the blood is effused either in the cerebral
substance, or in the ventricles; concussions of the brain
and apoplexy offer examples of them. The blood then
becomes a foreign body, whose presence occasion serious
difficulties. These difficulties should also be in part at- “
tributed to this, that the cerebral substance is disorganized
in a greater or less extent ; its colour is a yellowish red,
and its texture is softened. When death is not the con-
sequence of it, a membrane is formed around the blood,
this fluid is absorbed, and there remains only a serous
cyst, which also finally disappears. The spinal marrow
is likewise liable to experience this alteration ; it was
converted into a sort of porridge infiltrated with blood,
in a case observed by M. Gaultier de Claubry.

|The nerves are hardly ever ossified. The brain is so
sometimes ; various instances of which are found in au-
thors. They are almost always’ osseous productions, for
the most part loose, rarely adhering closely to the cerebral
substance. ‘Tumours, which seem to belong to the fibrous
or cartilaginous textures, are developed in the nerves, the
brain and even the spinal marrow. ‘They are hard, grey-
ish and separate the medullary fibres, which take no part
in their development. M. Dubois and Home have extir-
pated these tumours. Some refer them to the cancer of

NERVOUS SYSTEM OF ANIMAL LIFE. _ 65

the nerves. Cysts are formed in the brain; we have
already pointed out one of the circumstances under which
they are produced. They are often taken for hydatids.
These are rare in man, though they are sometimes found.

The scrophulous affection is the most common in the
brain. It appears under the form of tubercles of very
various size, round, greyish or yellow, soft and brittle,
the number of which is sometimes very considerable. <A
cellular membrane surrounds them. Cancer of the brain
has also been observed. ‘Finally M. Meckel speaks of
fungous and spongy tumours, analogous to the productions
called erectile, and which have their seat in this viscus.
They are extremely rare in it. The nerves are foreign
to almost all these alterations.

Ill. Alterations in the Development.

Clarke has given, in the Philosophical Transactions,
the description of a foetus so imperfect, that it had no
nervous system. It is the only fact of the kind known.
We often meet with acephalous foetuses, or rather aence-
phalous ones, that is to say, destitute of a part or of the
whole of the brain. ‘The spinal marrow exists in the
greatest number*bf cases, but in some it also is wanting.
Examples of this last kind are cited by M. Lallemand in
his inaugural dissertation. Ihave myself seen some. In
these cases, the peculiar membrane of the spinal marrow
forms the parietes of a cavity which contains a liquid, and
the nerves are implanted as usual into this membrane.
Otto, ( Treatise on Morbid Anatomy,) mentions many
cases in which the optic nerve and other nerves of the
senses were wanting in individuals destitute of sight,
hearing, &c.; the rest of the nervous system was as in
the natural state.

9

66 ; ADDITIONS, &c.

Anomalies are quite rare in the nervous system, espe-
cially in the portion of it which belongs to animal life.
Yet the brain sometimes exhibits an inequality in the size
of its lobes. Bichat was himself a remarkable example
of this. Hydrocephalus is most often a congenital affec-
tion. The canal of the spinal marrow sometimes continues
until after birth, as M. Portal and others have seen in
hydrorachitis. The nerves vary a little in their distribu-
tion, though it is more uniform than that of the arteries.

The nervous texture is never preternaturally produced,
if it be not in the case of the wound of which we have
spoken above.

- ADDITIONS

NERVOUS SYSTEM OF ORGANIC LIFE.

Insulation of the Great Sympathetic.

Page 252.—* It is evident that a line of demarcation
separates the nerves of the ganglions and those of the
brain, and that the method is inaccurate which considers
them as forming a single nerve, arising by some origin
from this last.’’ |

The great sympathetic has always been a subject of dis-
cussion among anatomists. Haller, Zinn, Scarpa and Legal-
lois have maintained, that it depended on the brain and the
spinal marrow, like the other nerves, and that, like them,
it only transmitted an influence which it receives from
these parts. Many other physiologists, on the contrary,

68 ADDITIONS TO THE

think that this nerve is insulated, by its arrangement as
well as by its action, from the rest of the nervous system.
Authenrieth makes it come from the general nervous sys-
tem; but he supposes that as its filaments pass through
the ganglions, they are less and less subjected to the cere-
bral action. According to Reil, the great sympathetic has
only filaments of communication and no origin, but it
enjoys the property of a semi-conductor. Gall, like
Bichat, makes a multitude of insulated systems of it, which
arises from the manner in which he has considered the
neryous system in general. Finally J. F. Meckel has
adopted a sort of mixed opinion according to which the
great sympathetic, though insulated, may depend, to a
certain extent, upon the central organs.

It would be superfluous to give in detail here the rea-
sons alleged for and against these opinions ; we shall con-
tent ourselves with pointing out the principal. Nothing
prevents us from calling, in the great sympathetic nerve,
points of origin, the points of communication of this nerve
with the spinal marrow and the brain, if we recollect
what ought to be understood by the term origins in the
nervous system; they are the central extremities of the
nerves, those which are the nearest the nervous centres.
All that has been said to prove that the ganglions are
these centres, only shows that there are great differences
of organization in the great sympathetic and the other
nerves. It is unimportant whether this series of gan-
glions and intermediate cords is considered as a single
nerve, or as so many insulated parts, united by anasto-
moses. But it is not so, to know if this system be really
independent of the cerebral, or if, as Legallois pretended,
it be on the contrary from this last that it derives all its
influence. We know the experiments of this physiolo-
gist upon animals from which he removed the brain and

j

NERVOUS SYSTEM OF ORGANIC LIFE. 69

afterwards supported life by means of artificial respiration.
The destruction of the spinal marrow constantly produced
death by the sudden cessation of the pulsations of the
heart. When the spinal marrow was destroyed only in
part, the pulsations were only weakened, cutting off the
limbs did not occasion the blood to flew, but life still
continued. Legallois concludes from them, Ist, that the
heart receives the’ principle of its action from all the points
of the spinal marrow, through the medium of the great
sympathetic ; 2d, that the integrity of the spinal marrow
is indispensable to the functions of this last. But we
have seen monsters born without a spinal marrow, and
yet they lived in the womb of the mother. Dr. Wilson
Philip having repeated the experiments which we have
just cited, found that the pulsations did not cease imme-
diately after the spinal marrow had been removed ; they
ceased quicker when it was violently torn out than when
it was taken away with care. The animals, subjected to
these experiments, resist also in general so much the
more in proportion as they are younger. Finally, in
many fishes, carps in particular, Mr. Clift has seen the
pulsations of the heart continue notwithstanding the lesion
of the spinal marrow. We ought then to have regard, in
the conclusions which we draw from this sort of experi-
ments, to the age and species of the animal. We may
apply to the spinal marrow, in this last respect, what is
elsewhere said of the brain ; it is, that in the inferior ani-
mals, the centres are much less necessary to the action of
the rest of the nervous system. Their less importance in
animals accords with their less development. So in man
and the superior animals, the great sympathetic depends
so much the less on the brain and the spinal marrow, as
these parts are themselves less developed, as, in a word,
the individual is younger. It is in this way, and not in

“0 - ADDITIONS TO THE

an absolute manner, that we should resolve the: question
proposed. |

Structure of the Ganglions.

Page 258.—“‘1 think then by admitting, even to a
certain extent, the internal arrangement that this author
(Scarpa) has observed in the ganglions, we cannot describe
these organs in the point of yiew in which he has present-
éd them.”’

The observations made by Scarpa have been repeated
in our time. The ganglions are composed, as this anato-
mist has demonstrated, of two very different substances,
before pointed out by Winslow. i

Ist. It is almost always easy to trace in the ganglions
- the nervous filaments which emanate from them; these
filaments preserve in them their cylindrical form, and.
white colour, and are easily distinguished from the non-
medullary substance, in which they are, as it were, buried.
It is often sufficient, according to the remark of Haase, to
cut a ganglion to perceive many small white points, which
are nothing but the extremities of the divided nervous
filaments, These filaments frequently anastomose. In
the ganglions situated in the-course of a single nerve,
their direction is parallel to that of the nerve itself; when,
on the contrary, many nerves unite to forma ganglion,
there is nothing uniform ; the medullary filaments are
seen interlacing in all directions, and thus establishing
numerous communications between these nerves. Hence
the ganglions of the first. species are elongated and usually
oval, whilst those of the second have a much more irreg-

ular form.

: ( :
NERVOUS SYSTEM OF ORGANIC LIFE, "4

2d. The peculiar substance of the ganglions is soft,
pulpy, like albumen or gelatine, of a reddish grey, some-
times yellowish, lodged in the interstices of a very deli-
cate cellular texture. It is separated with more or less
ease from the nervous filaments which it surrounds; this
separation is made with difficulty in the ganglions of the
great sympathetic ; the medullary filaments are very soft
in them and almost semi-fluid at their circumference, so
that their external layers are confounded with the grey
pulpy matter of which we are treating. The plexuses
exhibit nothing similar to this substance ; it is this which
distinguishes them essentially from the ganglions.

It has been thought that the grey substance of the
ganglions was the same with that of the brain; that the
use of both was to strengthen the white substance of the
nervous fibres. If we examine comparatively a ganglion
stripped of cellular texture and a portion of brain in which
the grey substance predominates, we shall see that this
resemblance does not exist. Without speaking of their
dissimilar appearance or of the physical characters which
distinguish them, the manner in which they are affected
by the various reagents establishes very striking differ-
ences between these two textures. This is a fact already
recognized by Bichat. The experiments of Wutzer leave
nothing to be desired upon this subject ; the following is
an extract from the comparative table which he has given
of the chemical properties of these two substances in his
Treatise de Gangliorum Usu et Fabricd.

_-

72°

Treated with

cold concen- y,

trated nitric
acid,

By the same |
acid boiling,

By a solu- (

tion of caustic
potash cold,

By a solu-
tion of boiling
caustic pot- 7

ADDITIONS TO THE

f The one, furnished by the cervical or semilunar gang-
lions, taken from an adult, stripped of their cellular tex-
ture and washed in distilled water, experiences the fol-
lowing phenomena; Ist, it undergoes the horny harden-
ing; 2d, at the end of eight days, the horny hardening
continues, the matter blackens, and gives, if agitated,
and afterwards left to deposit a friable precipitate, in
which there is still here and there discovered an appear-
ance of structure; 3d, at the end of a longer time,
putrefaction renders it liquid, but it exhales no other
odour than that of the acid.

The other, taken from parts of the cerebrum or cere-
bellum formed of three quarters or nearly of grey sub-
stance, Ist, is hardened without the horny hardening ;
2d, diminishes a little, and takes the consistence of
curd; gives, after having been mixed with the liquor by
agitation, yellowish albuminous flakes which swim;
3d, the odour of the solution has something similar to

Lthat of rancid oil.

al

The ganglion is dissolved; the liquor is only a little
turbid; by cold a slight precipitate is formed and a
small quantity of the matter comes to the surface.

The cerebral substance is dissolved but in part, a cer-
tain quantity swims upon the liquor; the solution pre-
serves its transparency after it is cold, though an infinite

Lnumber of medullary particles is seen suspended in it.

The first is softened a little ; its white filaments dis-
appear; its solution is slow and imperfect.
The second is dissolved mere easily ; one tenth of

the matter floats upon the liquid, and does not mix
with it.

f In one, some filaments remain insoluble; cooling is

followed by a deposition formed of globules of a deep
red.

In the other, the solution is almost complete; by
cooling, the surface of the liquid is covered with flakes

ash,

By boiling
alkohol,

_ of a yellowish white.

The substance of the ganglion is contracted, then
dissolved to two thirds; the liquor is turbid.

The cerebral matter hardens, and afterwards experi-
ences changes observed by M. Vauquelin ; albumen is

(obtained from it.

Finally, different reagents, which have no action separately on the

acid solution of these substances give precipitates when employed to-
gether; the alkaline solution presents the same phenomenon, when
treated with the muriatic acid, and then with nut galls. These pre-
cipitates furnish new characters by the differences which they exhibit in
their properties, according as they belong to the cerebral substance or
to that of the ganglion.

fez

a

NERVOUS SYSTEM OF ORGANIC LIFE. 3

No doubt a good analysis of the ganglions remains to
be made, in order to know precisely the difference which
exists between their substance and that of the brain, but
these data are sufficient to prove that these differences are
real. |

According to Scarpa, the peculiar substance of the gang-
lions is replaced by fat in very fat subjects; it appears
that this is not dlways so. When the corpulency has
been the greatest, there has only been found some fatty
vesicles under the peculiar membrane of the ganglions
(Wutzer). We can conceive that if fat should accumu-
late there, it would compress the grey matter, and make
it disappear in whole or in part.

Uses of the Ganglions.

- Page 273.—‘ Scarpa has collected the opinions of all
who have preceded- him, together with his own, upon
the uses of the ganglions. I refer to what he has said
upon this subject.”’ :

We can divide into two classes the opinions of physio-
logists upon the uses of the ganglions.

Some attribute to them purely mechanical ones, as that
of facilitating the distribution of the nerves, of effecting
the intimate mixture of the nervous filaments, of fayour-
_ ing their union, separation, &c. Meckel the elder, Zinn,
and Scarpa are of this number.

The others allow them functions of a higher order,
essentially vital, and think that they are designed to mo-
derate and even destroy the reciprocal influence of the
brain and the nerves. They thus explain how the organs
of the internal life are to a certain extent independent of

10

74 ADDITIONS TO THE

the cerebral action, and how the brain in its turn per-
ceives with difficulty the impressions made upon these
organs or upon their nerves. In a word, the two lives
do not differ more than in their neryous systems.

This idea, obscurely stated in the writings of Willis,
F, Petit and Bianchi belongs truly to Johnstone ; most
modern physiologists have adopted it. It must be
acknowledged that it accords very well with what we
know of the structure of the ganglions, and nothing
seems more capable of breaking the nervous force than
these medullary interlacings surrounded by a substance
wholly different from that of the nerves. It is asked
nevertheless why some impressions are transmitted not-
withstanding the obstacle which the ganglions present to
them ; why the vertebral ganglions do not perform in
respect to the parts which receive their nerves of them,
the same uses as the ganglions of organic life. The first
objection has been answered by saying, that the ganglions
are imperfect conductors, that they insulate sufficiently to
arrest ordinary impressions, but that very acute ones pass
through them. _Wutzer has seen the action of the gal-
vanic pile upon the lumbar ganglions cause very severe
pains, accompanied with convulsive motions, whilst a less
degree of irritation produced nothing similar. As to the
second objection, it can hardly be combatted except by
considering the differences of structure which the gang-
lions of the spinal nerves exhibit compared with those of
the great sympathetic, differences which ought to produce
a difference in the functions.

To concentrate the nervous power, to strengthen it, to
spread it uniformly upon all the apparatus of organic life
and thus to contribute to the regularity of their action,
are the uses commonly attributed to the system of which
we are treating. It is difficult to assign those of the

%

By

NERVOUS SYSTEM OF ORGANIC LIFE. 15

ganglions which are found in the posterior branches of the
nerves of the spinal marrow. |

Ganglions of Animals.

Page 274.—“ If the ganglions were not the centres of
certain important functions of which we are ignorant,
would they be so invariable in the animal organization ?””

It is difficult to determine to what part of the nervous
system the organs of this kind belong which are met
with in the lowest classes of animals. Worms and in-
sects have insulated swellings, united by nervous cords
which go off in the form of rays. In the mollusca, the
whole system consists of two great nerves twisted around
the oesophagus and an annular swelling which embraces
this tube. -Blumenbach, Cuvier, Gall and J. F. Meckel
admit that these parts correspond with the spinal marrow
of the vertebral animals. If, on the contrary, Reil and
many others are to be believed, it is the great sympathe-
tic that they represent. Walter of Landshut, assimilates
the nervous cords of the mollusca to the nerves of the
eighth pair, by comparing to the spinal marrow those of
insects and worms. Weber takes the ganglions of the
vertebral nerves as the term of comparison. But no one
can be exact; there are too many differences of structure,
distribution and functions between these imperfect ner-
vous systems and those of the superior animals. What
seems to approach nearest the truth is the term of com-
parison adopted by Walter for the nerves of the mollusea,
which in fact very much resemble the nerves of the eighth
pair.

For the same reason, we can hardly give the name of
ganglions to those swellings, or rather to ‘those irregular

76 ADDITIONS, &c.

masses, whose nature is still but little known, which ap-
pear to take the place, in the inferior animals, of the cen-
tral organs of which these last are destitute. It is how-
ever upon this resemblance that is founded in great part
the opinion of those who pretend that the brain and the
spinal marrow are assemblages of ganglions ; the proof of
it is, say they, that these paretions are insulated in the in-
ferior animals. We shall not again advert to this opinion,
which is contradicted by facts already stated in the or-
ganization, development, &c. of the nervous system. M.
Serres thinks, like Weber, that the insulated ganglions of
the inferior animals answer to the vertebral ganglions.

In animals who, like man, have the spinal marrow
enclosed in a bony canal, the system of the ganglions is
not by any means developed to the same degree. Ist.
Having regard to the whole size of the body, this system
is of so much the more extent as the animal is more
elevated in the scale of beings, consequently as his or-
ganization is more perfect. The eighth pair diminishes on
the contrary in the same proportion. 2d. Its develop-
ment is always in proportion to that of the spinal marrow
if we compare both in relation to the whole body in
general and not to the brain alone. 3d. The great sym-
pathetic follows also the alimentary canal in its develop-
ment. 4th. Finally, it is equally connected in this re-
spect with the vaseular system:

ADDITIONS
To THE

VASCULAR SYSTEM WITH RED BLOOD.

—— ee

Situation of the Arteries.

Page 292.—** Both of them” (the trunks and branches
of the arteries) ‘‘ are covered almost every where by a
thickness of parts that protects them from external in- -
jury.”

Besides, the arteries are almost every where situated in
the direction of flexion of the articulations. Thus the
aorta is placed in nearly its whole course in front of the
vertebral column. Thus the carotids on the anterior part
of the neck, the iliacs in front of the pelvis. and the sub-
clavians on the inside of the shoulder, all occupy the side
towards which the motions are the most extended. This
becomes more evident in the extremities.. We see, on

»

"8 ADDITIONS TO THE

the inferior ones, the crural artery at first situated in
front of the ilio-femoral articulation, that is to say, in the
direction of the flexion of this articulation, turning within
and behind to its inferior part, and preserving the same
relation with the articulation of the knee. The foot seems
at first to form an exception; but this exception is only
in appearance, what is called extenston in this part being
really the direction of flexion, if we compare it with the
hand, and is besides the direction of the most extended
motion. Moreover, it is in descriptive anatomy that we
must look to see to what extent every thing, in the neigh-
bourhood of an artery, unites to protect it efficaciously from
the injuries which might alter its structure. The arrange-
ment of which we are treating evidently contributes to
this object, as has been very well seen by Soemmering.
Without it the arteries would at every instant be exposed
to stretching, which, by elongating them too much, would
produce the double inconvenience of embarrassing the
circulation of the blood in their interior, and of producing
in their texture, which is but slightly extensible, inevi-
table ruptures. This situation of the arteries has also
another advantage ; it follows from it that in flexion, they
become much less liable to external injuries ; which, in
various places, remedies to a certain extent their super-
ficial position. :

In the spaces between the articulations, the arteries of
the extremities occupy in general their internal side, less
exposed than the others to the action of external powers,
especially when the limb is in adduction.

Termination of the Arteries.

Page 301.—‘* The pilous, epidermoid, cartilaginous
ystems, &c. destitute of arteries, contain only white

;
‘

VASCULAR SYSTEM WITH RED BLOOD. 79

fluids in the division of the general capillary system that
has its seat in them.”

In their termination in different organs, the arteries
exhibit also many points for consideration.

1st. The course they run before arriving at it is longer
or shorter. We meet in this respect with great differ-
ences, which themselves are not uniform, on account of
the varieties of origin so frequent in this system. In
general the arteries arise at a little distance from the
organ to which they are destined. When a contrary
arrangement exists, it arises from some local cause. It is
‘thus that the spermatic arteries are, at their origin, very
far from the testicles, because the testicles were originally
situated much higher up.

2d. The mode of distribution of the arteries, their
number and size vary in each organ. There are some
which possess many arteries ; this is the case even with’
the greatest number. Others, as the liver, the kidneys,
the spleen, &c. receive but a single trunk. The arteries
are almost always more or less divided before penetrating
the substance of the organs, as we see in the brain, the
bones, the muscles, &c. Sometimes they enter them on
one side only, and occupy but a very small space on their
surface ; sometimes almost the whole circumference of
the organ gives passage to them. Finally, their size
differs in the different organs ; it is generally in relation
with the nature of the functions which they perform.

3d. The arteries, when arrived in the textures them-
selves, give rise, by their divisions and subdivisions, to
very delicate networks. The form of these networks is
not the same every where; Prochaska and Soemmering
have pointed it out for a great number of parts. They
are trees in the intestine, stars in the liver, tufts in the

80 ADDITIONS TO THE

tongue, &c. ; so that we can by the aid of a microscope,
at a single glance, as it were, determine whence the ves-
sels come that are previously injected.

Resistance of the Arteries.

Page 306.—‘< This longitudinal resistance” (of the ar-
teries) ‘‘ to distension is less than the lateral resistance op-
posed to the injection ; experiments prove it, and it arises
without doubt from this, that no fibre, in the first case,
is found directly opposed to the effort.”

The cellular coat is in fact almost the only one capable
of sustaining an effort which is exerted in the longitudi-
nal direction, whilst the peculiar coat resists with it when
the effort is lateral. Besides, the resistance of the arteries
is not the same in all; it depends in general on the thick-
ness of their parietes; the cerebral arteries, which have
such delicate ones, are so much the weaker than other
arteries of the same size. For the same reason, the
trunks have more resistance than the branches, these than
the smaller branches, &c; only as the thickness does not
diminish in the ratio of the capacity, it follows that the
arteries ...e most distant from the part, are, in relation
to their caliber, the most resisting. Another cause, ac-
cording to Clifton-Wintringham, which makes the small
arteries resist more, is that their texture is softer and
looser.

But few comparative experiments have been made upon
the strength of the arterial parietes in the longitudinal
direction. ‘The object of those of Wintringham was to
ascertain the lateral resistance ; it appeared to him to be
greater, in relation to the thickness even of the parietes,
in the small arteries than in the large ones. The aorta

VASCULAR SYSTEM WITH RED BLOOD. 81

has alse borne a greater effort at its inferior extremity
than near its origin. Gordon has endeavoured to measure
the effects of the distension ; he has ascertained that if
requires a greater weight to rupture the external iliac,
than the carotid. But in his experiments, the rupture
took place where the suspensory cord was attached ;
there was at the same time a section of the artery;
so that nothing can be concluded from it in relation
to pure and simple distension. If we should wish to
repeat these experiment, which, however, do not appear
to lead to any very important result, we might insulate
the artery of a limb for a certain extent without entirely
separating it, and afterwards employ upon this dis-
articulated limb all the necessary efforts. We should
avoid in this way the inconvenience of ligatures.

In the arterial curvatures, the convex side is thicker
and stronger than the concave one. This arrangement,
no doubt accommodated to the greater effort of the
blood on that side, is very evident at the arch of the
agrta.

Nature of the Middle Coat of the Arteries.

Page 308.—‘‘ The action of different reagents upon
the arterial texture, proves clearly how much it differs
from the muscular. There are then general phenomena
common to all the solids; but different peculiar phe-
nomena that are distinctive.”

Those who consider the peculiar membrane of the
arteries as of a muscular nature, and Haller, Walter and
Soemmering are of this number, think so, Ist, because
its fibres become soft and greyish in the small arteries,
and resemble very much, at least in appearance, those of

11

a

$2 : ADDITIONS TO THE

the intestine, bladder, &c. ; 2d, because the same appear~
ance is found in animals; 3d, because, notwithstanding
the dryness, resistance, elasticity and species of brittleness,
which distinguish the arterial fibre, there is not more
difference between this fibre and the muscular, than is
found between the different kinds of muscles; between
the great pectoral of birds and the muscles of their
claws or stomach, for example; 4th, finally, because
the properties which the arteries enjoy during life also
approximate their texture to the muscular. It might
be added, that it is not very dissimilar in chemical
properties ; for [I am confident it contains a certain
quantity of fibrin.

These considerations nevertheless di not seem to me
to ve sufficient to warrant us in ranking the arterial
texture among those which have the muscular fibre
essentially for their base. I think rather, considering
the elasticity which forms the principal character of it,
that this texture belongs, as some anatomists have already
thought, to the yellow or elastic fibrous system which
will be examined hereafter. :

Cellular Membrane and Sheath of the Arteries.

Page 318.—‘* The arteries have around them two
kinds of cellular texture ; one, which is very external,
logse, fatty, full of serum, with distinet layers, unites
them to the neighbouring parts; the other, firm, com-
pact, not fatty, filamentous and not lamellated, forms
the first of their coats.”

This cellular. coat, (cellulosa propria of Haller) re-
jected by Monro, Walter, Scarpa and Mascagni, and
which Soemmering united to the peculiar membrane, is

VASCULAR SYSTEM WITH RED BLOOD. 33

not less distinet from the other coats which ‘it covers,
than from the cellular texture which surrounds it.

It is a fibro-cellular membrane, delicate, tolerably
dense however, and’ really forming a constituent part
of the arterial tube. In the great arteries it is divided
into two lamine; one external, which approxim’&tes
more to cellular texture ; the other internal, yellowish
and tough, which resembles the layers of the middle
coat. Its appearance upon the arteries of the middle.
size is that of the apeneuroses, or still more of the neu-
rilema. Its texture is composed of fibres interlaced and
oblique, more separated without than within; these
fibres ard especially apparent in the distension of the
artery, either lengthwise, or across, because they stretch
and separate before breaking. Mascagni has given a
good plate of them.. The small arteries have this coat
thicker than the large ones, in proportion to their size ;
it is on this account that they bear ligatures better,
which, as is known, only act upon the cellular coat.

Into this membrane are inserted many soft and exten-
sible filaments, which come from a species of sheath
which the artery receives from the surrounding cellular
texture. It is the only relation which there is between
it and this cellular texture. By means of this arrange-
ment, the artery slides easily in the interior of its cellu-
lar canal; the retraction of divided arteries is very much
favoured by it.

The cellular sheath of the arteries, the external coat
of Soemmering, described by Haller under the name of
tunica cellulosa adscititia, is in fact nothing but this
Jamellated cellular texture which joins and embraces them
so as to form a real canal around them. Hebenstreit has
treated of it in a dissertation which forms a part of the
Collection of Dissertations of Haller. This sheath is

84 ADDITIONS TO THE

attached on one side to the external membrane by the
elongations of which we have just spoken, and is con-
tinued on the other with the cellular system. . It is
wanting in some arteries which have. serous. coverings.
Others are destitute of it, from the want of cellular tex-
ture in the parts where they are found. Its arrangement
varies like that of this texture; in general compact on
the extremities, it is very loose in some. parts, around
the spermatic. arteries for example. These. differences
deserve an examination, because they may explain various
morbid phenomena. ‘Thus arterial ruptures are followed
in the brain by a-general effusion which disorganizes its
substance, whilst: in the extremities the cellular sheath
prevents this accident by circumscribing the progress of
the effusion; thus, in this last case, the blood. infiltrates
to a greater or less extent according to the’ resistance.
which the sheath opposes to it, &c.

Nerves of the Arteries.

Page 322.—* There is merely juxta-position”’ (between
the cerebral nerves and the arteries) “‘ as we see it in the
extremities, in the intercostal spaces, &c.’’

The nerves of the arteries are so much the more. abun-
dant in proportion as these vessels are of a less caliber ;
they are more evident upon the branches than the trunks."
Those of the arteries of the extremities come in part from
the cerebral nerves. Lucae says that he has traced them
into the arteries. He has made two classes of them in
relation to their course; lst, some stop in the cellular
coat and are lost there, after having run some time in the
cellular texture which surrounds it; 2d, others pass
through this coat and go to the peculiar membrane, upon

VASCULAR SYSTEM WITH RED BLOOD. 85

which they are spread into a very delicate network. ‘The
first are short and flattened; the second, which are ex-
tremely delicate, have a little more consistence, their form
is rounder and they run a shorter course. No one reaches
the internal membrane ; Oudemann says however that he
has traced them to the nervous membrane of Haller. Some
arteries appear to be destitute of nerves. The pulmonary
tree receives fewer of them than the aortic. According to
Lucae, the nerves of the arteries are less apparent in old
age, particularly the filaments destined for the middle coat.

Trritability'of the Arterial Texture.

Page 332.— The contraction produced by the defect
of extension, is that which characterizes the contractili-
ty of texture. Irritability or sensible organic contrac-
tility, on the eontterys tae 25d supposes the applica-
tion of a stimulus.”’

Notwithstanding all these considerations, there are phy-
siologists, who allow to the arterial texture the faculty of
contracting under the influence of an appropriate stimulus.
The reasons which they allege in favour of this opinion
are the following. Ist. If the arteries, say they, do not
always contract in experiments, they resemble in this res-
pect some textures of whose irritability there is no doubt.
The intestines, the bladder and the stomach sometimes
give no sign of irritability. 2d. The action of the acids,
which Bichat considers as a mere horny hardening, is dif- .
ferent during life and after death ; in the first case, there
is a real contraction ; in the second, it is rather a kind of
erosion, as Verschuir hasseen. 3d. The same author has
succeeded in producing a contraction of the artery, by
merely irritating it with a scalpel. 4th. In other experi-

86 ADDITIONS To THE

ments, the simple contact of the air has produced a-sudden
and very evident contraction, sufficient to efface almost
entirely the cavity of the artery. 5th. This contraction,
in all these cases, extended beyond the point touched ; it
ceased when the stimulus was removed. 6th. The elec-
tric spark has also produced contractions according to
Bikker and Van-den-Bos. 7th. It is even said that this
effect has been obtained by applying stimuli to the nerves
of the arteries. Galvanism has been successfully employ-
ed in this way by Giulio and Rossi. Home employed
alkalies; their contact with the great sympathetic nerve
produced violent pulsations in the carotid artery. He
was led to this experiment by the local changes which
the circulation appeared 1o experience from severe pains
from an ulcer. 8th. Thomson has seen the arterial
parietes contracted by the action of ammoniac, so that its
cavity seemed to have entirely disappeared. The muriate
of soda, on the contrary, almost uniformly dilates them.
Many of these experiments require, no doubt, to be
repeated; but we cannot deny, that the contraction of the
arteries may be very different during life from what it
is after death; for, 1st, an artery, opened between two
ligatures, does not continue to empty itself ‘some instants
after death, except from an excess of distension, its elas-
ticity does not make it contract. 2d. Arteries, empty at
the moment of death, and being still contracted in virtue of
this contraction, return to their ordinary dimensions when
all vital influence has entirely ceased; their elasticity,
which resumes its ascendancy, then supports their parietes
separate; this is what is seen especially in death, from
hemorrhage ; 3d, so in the experiments cited’ above,
the contraction ceased after death, and that which
was obtained by putting the elasticity in action by
the distension of the parietes was much less marked. Ne

;

VASCULAR SYSTEM WITH RED BLOOD. | 87

doubt that the force which thus makes the arteries con-
tract during life does not differ from that which presides
over the contraction of the heart, the intestines, &c. ;
perhaps it is wrong to give it the name of zrritabzlity ;
but that of contractility of texture is no more suitable
to it. Kramp has proposed to make a particular force of
it which he calls the vital force of the arteries. Parry
refers all its effects to tone or insensible organic contrac-
tility. Whatever be itsnature, its intensity inereases as the
arteries become smaller, which Soemmering attributes
to the greater quantity of nerves which the small ones ~
receive ; the elasticity diminishes in the same proportion.

Action of the Arteries in the Circulation.

Page 345.—“ It is not the contraction of the arteries
that drives the blood to their extremities. Each jet of
the arterial throw should correspond to each relaxation of
the ventricle; the contrary of this is the case as I have
just said.’?

If the arteries do not contract upon the blood, the flow
of this fluid would not be continuous but intermittent :
whilst it is, as it were, remittent. The jet of an open
artery is increased at each contraction of the ventricle,
because this contraction increases the velocity of the cir-
culation. It is diminished in the relaxation because there
is then only the arterial action which makes the blood
flow. The jet should cease entirely at each relaxation of
the ventricle, if it was only owing to the contraction of
this last. There are then two causes of the motion of the
blood. 1st. The arteries, always full, constantly tend, by
their elasticity and contractility to react upon this fluid.
2d. The contraction of the heart is added to this by in-

88 ADDITIONS TO THE

tervals, and gives to the motion a new activity. This
Jast cause is much the most important, especially in the
great arteries, but the first is nevertheless real. eo

_ Development of the Vascular System.

Page 364.—“< The arteries are made to develop them-
selves, and the heart does not hollow them out, as Haller
has said, in the interior of our organs by the force of its
impulse. This mechanical manner of considering their
formation is evidently contrary to the known laws of the
animal economy.”

The opinion of Haller is so much the less admissible,
as it appears that there are vessels before the heart exists.
The development of these vessels, and in general of the
whole vascular system, is a point still obscure, but never-
theless curious. Malpighi, Haller, Wolff, and especially
in recent times Pander, have traced it in the chick. The
first vessels appear in the membrane of the yolk, which
represents the umbilical vesicle of man and the superior
animals, The vein of this part appears before any of the
rest of the vascular system. Its ramifications commence
by small insulated cavities, species of vesicles, which are
afterwards united by grooves... They are at first mere
hollowed passages in the membrane of the yolk, filled
with a colourless fluid; the blood afterwards shows its
colour in them, the parietes become more distinct and their
consistence greater. The small branches, branches and
trunk of the vein are developed in thesame manner. The
vena porta succeeds to that of the vesicle, of which it
appears to be but a continuation. Soon after this vein is
enlarged at its superior extremity to'give origin to the
heart. This is then semicircular, and formed entirely by

VASCULAR SYSTEM WITH RED BLOOD. 89

the left ventricle. The origin of the aorta is afterwards
joined to it and then the auricle; both at first quite dis-
tinct from the ventricle, gradually approximate it. The
space which thus exists for some time between this last
and the auricle, is the auricular canal. From the aorta
arise successively all the other arteries, beginning with
that of the yolk or vesicle, which the vessels of the
allantoid membrane soon follow ; the development of the
arteries is followed by that of the corresponding veins.
On the other hand, the liver is developed and the vena
porta, united to the umbilicus, is almost exclusively dis-
tributed there ; the portion of this vein which is extended
beyond forms the ductus venosus. The cavities of the
heart are completed ; a partition divides the auricle into
two parts, which still communicate by a large opening ;
there arises from the superior part of the left ventricle a
small tubercle, which by extending towards the apex of the
heart, gives origin to the right ventricle. At this period,
the base of the heart which the left side alone forms, estab-
lishes a communication between the two ventricles, which
makes the aorta seem to arise from both of them ; the
pulmonary artery is yet only indicated by a bifurcation
which the aorta exhibits a little above its origin ; the two
branches which result from this bifurcation unite again
after a short course. In the ulterior deyelopment of the
heart, the place of their separation is found more and
more approximating this origin ; the two divisions finally
detach themselves entirely, and the pulmonary artery
becomes a trunk insulated at its origin, and forming as it
were a second branch to the aorta. It is itself divided
for the lungs of each side, and takes beyond the name of
ductus arteriosus.

By admitting that these phenomena, observed in the

oviparous animals, take place also in man, as some facts
12

90 _ ADDITIONS TO THE

seem to prove, we see, Ist, that in the beginning the
circulating organs are much less numerous than they are
to be afterwards. The heart has but one ventricle and
one auricle; the vena porta is the only venous trunk, the
aorta the only artery, &c.' The motion of the blood must
then be very simple at this period; this is also what is
observed in the chick. The blood, in this last, runs a very
simple course at the commencement ; it is asingle circle,
formed by the vein of the yolk, the vena porta, which is a
continuation of it, the heart, the aorta and the artery of
the yolk. There must be added to it afterwards the um-
bilical vessels, whose development follows nearly that
of the vessels of the vesicle ; this gives a little more extent,
to the cireulation without rendering it much more com-
plicated. 2d. Ina second period, on the contrary, the
circulatory organs are more numerous than: after birth.
Thus the ductus arteriosus, the ductus venosus, the um-
bilical arteries and vein and the foramen ovale are after-
wards to disappear.. There however remain traces of the
simplicity of the first period; the auricles, though two in
number, communicate together; the course of the blood
is much more complex, but the two circulations are still
in’ part confounded. It is not until this second period
that the circulation begins to be well understood in man.

——

MORBID ANATOMY OF THE VASCULAR SYSTEM WITH
: RED BLOOD.

I. Alterations in the External Forms.

The arteries often increase in size, either in their
whole extent, or in a single point, or even on one side
‘only of their cireumference. The increase of the arteries

VASCULAR SYSTEM WITH RED BLOOD. 91

in their whole length is a real hypertrophy, which takes
place when the organs themselves are the seat of an
excess of nutrition, when they experience a very acute
and long continued irritation, and under various circum-
stances pointed out above. After the obliteration of an
artery, the collateral branches do not increase in breadth
only, but in length also ; thus they describe curves which
did not before exist. The partial dilatation constitutes
one of the varieties of aneurism, the true aneurism of the
ancients. This affection is in fact in the beginning only
a simple, circumscribed and sac-like dilatation of the three
arterial coats, as is proved by many observations ; the
artery is rarely dilated uniformly and in its whole cir-
cumference ; when this takes place the disease exhibits
differences sufficiently striking to warrant us in distin-
guishing it, as Scarpa has done, from aneurism; these
two kinds of dilatation are sometimes united.

The contraction of the arteries is less common than
their dilatation. 1st. It is observed whenever the blood
ceases to pass through them, or does it in less quantity, as
happens in gangrene, especially in that variety known
under the name of dry gangrene, in some cases of atro-
phy, paralysis, &ce. 2d. Cirecumscribed contractions, the
cause of which it is very difficult to determine, have been
met with, particularly in the great arteries, such as the
aorta and the pulmonary artery. In the greatest number
of cases the texture of the artery is however sound ; some-
times it has been found thickened. There is often con-
nected with this alteration some organic disease of the
heart, or even the rupture of this organ. 3d. Various
tumours, situated in the course of the arteries may also,
by the pressure they exert, diminish their caliber more
or less. Old aneurismal tumours produce this effect upon
the arteries in which they are situated, and upon the

92 ADDITIONS TO THE -

branches they are near and which they compress.. Under
almost all these circumstances, the contraction of the ar-
teries may extend even to their obliteration. us

The manner of distribution of the arteries undergoes
important changes when a principal trunk is obliterated
in a part; there is then formed one or more anastomosing
passages which supply the place of the trunk in the
whole course of its obliteration, and which carry the
blood from the last branch furnished above the obliterated
trunk, to the first furnished below it. This is what is seen.
in ligature of an artery, after wounds of these vessels,
aneurisms, &c.

Il. Alterations in the Organization.

The internal membrane is much more susceptible than
the, others to inflammation.. Sometimes this state is first
developed in this membrane, sometimes it is transmitted
to it from other organs ; it is thus that in acute inflam-
mation of the thorax or abdomen, the internal membrane
of the aorta has sometimes been at the same time found
greatly inflamed; in the affected parts themselves, the
arteries commonly partake of the inflammation of the
other textures. The redness which characterizes this
arterial phlegmasia is usually accompanied by a thicken-
ing of the membrane and an effusion of an albuminous
nature, sometimes very copious; the vessels of the pecu-
liar membrane are also frequently more or less engorged.

Inflammation of the arteries is followed by their oblitera-
tion, when the two sides of the inflamed internal mem-
brane unite together. This adhesion is owing, like most
of the phenomena of this kind, to the circumstance: that
the effused fluid passes to the solid state and forms a sort
of false membrane which afterwards becomes organized,

VASCULAR SYSTEM WITH RED BLOOD. 93

It is in this: way that we can understand how, notwith-
standing the destruction of the arteries in ulcers often-
times very extensive, no hemorrhage takes place ; the
preceding inflammation has first obliterated the vessels.
Pus has never been found in the arteries; perhaps it is
earried off by the blood, as fast as it is formed. Ought
we to refer to a state of induration or of chronic inflam-
mation many of thé organic diseases of the arteries, which
are accompanied bya greater thickness and consistence of
their texture? This question cannot be resolved. What
is certain is, that inflammation, connected either inciden-
tally, or as effect or cause, is often united to similar altera-
tions. | Gangrene never succeeds to the inflammation of
the internal membrane alone; but the arteries are often
comprehended in eschars ; it happens then, that the blood |
is coagulated beyond the dead portion, so that there is no
hemorrhage when the eschar separates, unless the ne wom
be very large.

The cellular texture exterior to the arteries is subject
to the same alterations as the rest of the cellular system ;
inflammation may engorge, thicken and ulcerate it, suppu-
ration may destroy it, &c. The cellular coat, properly so
called, is but very rarely inflamed. When it happens and
the inflammation is long continued, there sometimes
results from it that sort of brittleness which has been
treated of in the article on the cellular system ; a brittle-
ness which has perhaps, however, been much exaggerated.

That ‘state of the arteries of which Bichat has spoken
and which resembles their inflammation, because it con-
sists in a more or less extensive redness of their internal
membrane, has been met with in cases in which it could
be attributed neither to maceration, exposure to the air,
the presence of a coagulum nor to the time that had
elapsed since death. (See Hodgson on the diseases of the

94 ADDITIONS TO THE

arteries.) We know not then if it be not, under some
circumstances, a real morbid alteration. According to
Franck, this redness was constant and occupied the whole
extent of the arterial system ina species which he had
occasion to observe.

The solutions of continuity of the arteries differ, accord-
ing as they penetrate the cavity of the vessel, or affect
only a part of its membranes.

The first case, which is the most hecenheaaill been
very well observed by Dr. Jones upon dogs. I have also
made some experiments upon this subject. The follow-
ing is what takes place when an ary of a living animal
is opened.

Ist. If it be by a simple puncture, with the point of a
needle for example, a small quantity of blood flows, a
coagulum is formed in the cellular sheath and stops the
hemorrhage. This coagulum afterwards disappears, the
edges of the opening inflame, and adhesion takes place.
The cicatrix is confounded in time with the arterial tex-
ture, and no traces are left of the small wound. The
cavity ofthe artery is preserved. rt

2d. When the wound is of some extent, the issue is
different according to the state of the cellular sheath and
the direction and size of the opening. If the sheath has
been destroyed, the hemorrhage continues in all cases ;
and, though suspended for a time by syncope, it only
ceases with the life of the animal. When, on the con-
trary, the sheath remains uninjured, 1st, if the wound be
longitudinal, to the jet of blood which escapes, succeeds
the formation of a clot which shuts the opening ; then this
cicatrizes, as in the case of simple puncture ; only the
cicatrix remains» apparent ; it is linear, continuous with
the texture of the artery, and is seen very well by open-
ing this last and examining its parietes against the light ;

he

VASCULAR SYSTEM WITH RED BLOOD. 95

2d, if the wound be'transverse, but occupying only a quar-
ter of the circumference of the artery, the hemorrhage,
though more abundant than in the preceding case, because
the retraction of the. arterial fibres gives a circular form
to the opening, may still stop of itself, and its suspension
be followed by the formation of a cicatrix, of which I
have preserved examples ; 3d, if the wound embraces
half the circumference of the artery, the opening takes an
elliptical form, and death necessarily ensues ; 4th, finally,
if. three quarters of the circumference of the artery
have been divided, the separation is very considerable ;
the opposite ends of the artery, extremely elongated,
represent, if we may so say, the extremities of two pens
united at their points; the kind of tongue that unites
them is finally broken, and the cure, when it is effected,
is made by the obliteration of the vessel.

3d. In complete transverse sections, death does not
take place unless there is at the same time denudation of
the artery. When the sheath is left, the wound is almost
always cured in animals by an obliteration of the artery.
The two ends retract into the: interior of their cellular
eanal, which thus extends beyond their extremity. The
hemorrhage brings on weakness and syncope; the blood
is effused and finally forms a coagulum which, filling the
sheath, surrounds the artery and shuts its extremity.
When the force of the heart returns, the coagulum resists
and the hemorrhage does not again come on. The blood
coagulates in the artery as far as the first collateral
branches, the parietes of the vessel contract, a cicatrix is
formed at each end and obliteration takes place. This
obliteration is, according to Jones, the result of a lym-
phatic effusion which is poured out in the artery near its
extremity, between the external and internal coagula.

When this takes place, the coagula are absorbed and dis-
appear.

86 ADDITIONS TO THE

The same things do not always take placein man. In
punctures, for example, it is extremely rare that the cure
is solid, unless the artery is at the same time obliterated.
The hemorrhage in this case left to itself, continues with-
out interruption ; the blood, if it does not flow out, is
effused into the cellular texture, and produces a diffused
or primary false aneurism. Suppose that by compres-
sion or rest, a coagulum should be formed, and a cicatrix
even established, the cure may be only apparent. Though
this “state may continue for years, the blood will finally
remove or break these feeble barriers and a tumour will
appear; this will be a circumscribed or consecutive
false aneurism. Such is at least the result of facts ob-
served up to the present time. It is true that we are
almost always ignorant of the direction and extent of the
wound ; and, as has been seen, the termination is very
different in this respect. It is thus extremely probable
that a puncture made lengthwise would heal as well in
man as it does in animals.

‘Spontaneons cure is likewise very rare, in man, of
wounds which comprehend the whole circumference of
the artery ; and, unless the caliber be very small, these.
wounds, left to themselves, are uniformly fatal. It is
necessary however to except from them, Ist, certain cases
in which, notwithstanding the considerable size of the
vessels opened, a coagulum formed during a syncope
has been sufficiently powerful, or rather the circulation has
been sufficiently feeble, so that the hemorrhage has not
reappeared and the adhesive inflammation has had time to
take place ; examples of this kind are cited by Boerhaave,
Garengeot and others. 2d. Wounds from fire-arms and
those which result from: the action of fire and caustics ;
here it is the eschars which prevent the hemorrhage, and
when they fall off the vessels are often obliterated. 3d.

VASCULAR SYSTEM WITH RED BLOOD 97

Lacerated wounds; I have collected a number of observa-
tions respecting them made by authors; the most re-
markable is the case of Samuel Wood, related in the
Philosophical Transactions, and since in various works.
In some of these observations, death has been the con-
sequence of a copious hemorrhage ; buf in the greatest
number, as also in ‘the experiments which I have made
upon animals, a cure has taken place. Besides the retrac-
tion and contraction noticed by Bichat, two additional
causes are opposed in this case to the flow of blood, and
favour the obliteration of the artery. In fact, at the instant
even of the accident, this yields and is elongated before
breaking ; but the internal membranes, less extensible,
are torn at first unequally and in different places, and
then are completely separated, whilst the cellular coat
continues to stretch, approximating more and more the
axis of the vessel, like a tube of melted glass drawn at
both ends. When the separation is completed, the artery
exhibits then at its extremity a conical elongation, ter-
minated by a narrow opening, and in its interior irregu-
lar shreds which obstruct its cavity. This last circum-
stance appears to be the most important of the three, for,
ist, the retraction is often wanting, the end of the artery
is pendent, and yet there is no hemorrhage; 2d, by cut-
ting in an animal the summit of the kind of cone which
the artery forms, the flow of blood does not return,
unless the section be made above the internal lacerations.

Solutions of continuity, which affect but one part of
the arterial membrane, act upon the internal or external
coats. Hunter and Home have seen, that if the internal
membrane be laid bare in dogs, by cutting the external
and middle ones, there results from it an albuminous
exudation, by which the thickness of the artery is in-
creased. They have even removed these membranes ta.

13

98 ADDITIONS TO THE

a certain extent, without the internal one being distended
by the blood. This must however take place in man
in what is called mixed or internal mixed aneurism,
aneurysma herniam arterix sistens, in which it is
supposed the sac is formed by the internal membrane
dilated. Many authors reject this kind of taper:
but examples of it have been given. |

It has been thought, that the distension of the arteries
during life, in violent motions, might produce the rupture
of the internal membranes and thus dispose to aneurism.
But the arteries are everywhere so arranged that it is
impossible that their distension can occasion even a par-
tial rupture, of which it is easy to be convinced on the
dead body ; this would not happen unless their parietes
were the seat of some organic disease. This internal
rupture is observed, on the contrary, under the following
circumstances. st. By pressing with a pincers an artery
of an animal, we effect the division of the internal and
middle membranes, the external one remaining whole ;
the small wound, which results from it, cicatrizes, and
the artery loses nothing of its strength in this place ; its
parietes are even rather thicker; when there is a great
number, of lacerations, the obliteration of the artery is
sometimes the consequence. 2d. What in the preceding
case, happens to a moderate extent, takes place circularly
from a ligature, as has been elsewhere said. There is
also this difference, that the edges of the wound being in
contact are agglutinated by a mechanism analogous. to
that of the reunion of wounds by the first intention. The
artery is then obliterated ; the blood is coagulated above
and below the cicatrix, as far as the first collateral
branches ; the obliteration goes all this extent. If these
branches are very near, the coagulum being very weak,
the cicatrix is not maintained, and a hemorrhage may take

VASCULAR SYSTEM WITH RED BLOOD. 99

place when the ligature comes off, and even before, when
the membranes begin to be broken. Jones says that it
is not necessary for a ligature to remain applied upon an
artery in order that obliteration should take place; by
placing many ligatures and removing them successively,
he has seen this effeet produced. Travers assures us that
obliteration is certain when the ligature has remained
applied for an hour; though the blood often resumes its
course at the end of that time, the artery is not the less
obliterated, according to the experiments of this author.
I have uniformly seen in my experiments the artery re-
main permeable, when the ligature has been removed
even at the end of twenty-four hours; it was not closed
definitively until the adhesion was established at the mo-
ment the ligature came off, which commonly happened
at the end of eight and forty hours. 3d. If an aneurism
be of any standing, the internal membranes yield to the
distension, as we have seen; they are torn by the mere
effort of the blood or by any external violence. The
tumour, which is then formed by the cellular coat alone,
makes more rapid progress ;.the blood coagulates in its
interior and forms fibrous layers, the density of which
increases as they are removed from the axis of the vessel ;
the sac, freed from these coagula, exhibits on its internal
surface an irregular line which indicates the point where
the membranes cease; these are sometimes floating, and
exhibit a sort of incomplete partition which separates the
cavity of the sac from that of the artery ; this is the
true aneurism, arrived to that degree which some have
called external mixed. In time, the cellular coat itself
is affected, it is destroyed, and the sac is formed only of
the cellular texture and the other surrounding parts. 4th,
In another species of aneurism, which, at an advanced
period, does not differ sensibly from the preceding, and

100 ADDITIONS TO THE

which has been designated under the same name, but
which others call spontaneous aneurism, the destruction
of the membranes precedes the formation of the tumour.
This destruction is here owing to the ulceration or rup-
ture which the internal membrane experiences in organic
diseases ; the blood is then confined below this membrane
and distends the cellular coat. This variety of aneurism
is perhaps the most common ; but it is not correct to say
that all begin in this way. Moreover, the ulceration of
the internal membrane is not always followed by aneu-
rism ; M. Cruveilhier has found this membrane des-
troyed as well as the fibrous, and yet there was no dila-
tation of the cellular coat.

Foreign bodies, in contact with the -arterial texture,
inflame and often ulcerate it so as to open the cavity of
the vessel. If these bodies act by approximating to each
other the parietes of the artery, they produce an adhesion
of these parietes. When they make a circular constric-
tion, like a ligature, they produce mortification in the
narrow portion which they embrace, and are afterwards
removed with it ; this is what takes place with a ligature
at the end of from eight to twenty days.

We know the frequency of arterial ossifications ; they
exhibit many forms. There are circular ones which
invade arteries almost in their whole length; they ex-
tend to the peculiar membrane, and are sometimes attend-
ed with a contraction and obstruction of the vessel ; that
species of gangrene which is called senile is oftentimes
the consequence of it. In other cases, the incrustation
is much more limited; there is only on the interior of
the artery a great number of small white marks, super-
ficial and but slightly prominent. Between these two
extremes are found yellowish plates, semi-transparent and
irregular, which appear at first to be situated in the space

VASCULAR SYSTEM WITH RED BLOOD. 101

between the two membranes, but which the blood after-
wards touches immediately, because the internal one is.
destroyed on their surface.

The cartilaginous transformation has also been: observed
in the arterial texture. It has its seat in the internal
membrane, ‘and is characterized by plates of a white
colour, prominent, fibrous and very dense. The carti-
laginous state almost uniformly precedes the _ ossifica-
tions of the arteries which take place in adult age, whilst
those of old people are owing simply to irregular deposi-
tions of calcareous matter.

The arteries are changed into a fibrous or ligamentary
texture, whenever their cavity is obliterated ‘naturally or
preternaturally.. This texture in time becomes more
delicate, and disappears itself or is confounded with the
cellular texture.

There are some morbid slbeatines peculiar to the arte-
rial texture; they have hardly any thing in common
with those binds affect the other textures. 1st. Some-
times in aneurisms the internal membrane is found thick-
ened, softened, and as it were fungous. 2d. Growths
similar in form to those which are the product of syphilis
have been met with in the aortic valves; Hodgson has.
even seen them in the femoral artery. 3d. The deposi-
tion of a pultaceous substance on or under the internal
membrane is a much more frequent alteration. It has.
been compared to steatoma; but there is a greater anal-
ogy between it and the tubercular affection. Sometimes
this substance, irregularly disseminated, forms on the inte-
rior of the artery small yellowish granulations, covered
with an extremely delicate pellicle ; sometimes, accumu-
lated between the internal and the fibrous coat, it forms
round masses, which obstruct more or less the cavity of
the vessel, or even real centres, filled with a purulent,

102 ADDITIONS TO THE

opake and yellowish fluid. The tumour, in the last case,
terminates sometimes by opening into the artery. At
others, the substance hardens and assumes all the charac-
ters of the osseous productions; it then contains much
phosphate of lime. This affection is often connected
with the osseous transformation. Both are common in
aneurisms especially the first.

The arteries partake of the affections of the organs of
which they make a part. Their destruction, in cancer-
ous, tubercular and other affections, produces various
hemorrhages; sometimes, however, their obliteration
prevents the flow of blood.

Ill. Alterations in the Development.

Without speaking of the numberless varieties of origin,
distribution, &c. observed in the arteries, and which,
being all different from the natural arrangement, exert
however only a very limited influence upon the cir-
culation, it will be sufficient to point out some of those
the importance of which is greater in this respect. The
heart has been seen wanting with all the superior parts,
and consequently also their vessels. In the heart itself,
it sometimes happens that there is but one auricle and one
ventricle ; the pulmonary artery arises then from the
aorta. Or it is the partition between the ventricles that
is perforated; or it is the foraman ovale which is pre-
served, or the ductus arteriosus that remains permeable.
In one instance the aorta terminated immediately after
its ascending portion, and the pulmonary artery continued
it below. In another, the trunk of the first was bifur-
¢ated so as to embrace the trachea and oesophagus.

Besides the capillaries which are developed under
many circumstances, arteries of a certain size are some-

VASCULAR SYSTEM WITH RED BLOOD. 103

times preternaturally produced. Charles Parry says that
he has found, in a sheep in whom he had divided the
carotid artery; mew arteries which went parallel from
one of the two ends to the other, the whole extent of
the éicatrix, and thus reestablished the circulation.

ADDITIONS
TO THE

VASCULAR SYSTEM WITH BLACK BLOOD.

Venous Valves.

Page 406.—“ We find in the works of Haller very
minute descriptions of the general arrangement, form
and position of the vascular folds of which we are treat-
ing.”

The following should be added to what Bichat has
said.

1st. These valves are more numerous in the superficial
than in the deep-seated veins, in those of the extremities,
than in those in the interior of the trunk; the superior
extremities have fewer of them than the inferior. In gen-
eral they are not found in the branches of communication

14

106 * ADDITIONS TO THE

of the veins, such as the median of the arm. The veins
of the heart are entirely destitute of them; itis usually the
same with those of the uterus. The spermatic veins of

‘woman have no valves, those of man have. It is on the
inferior part of the extremities that there are the most of
them; the veins of the exterior of the head contain but a
small number; there are usually some at the opening of
the branches in the trunks. |

2d. The loose edge of these valves is thicker than the
rest, and forms, like the adherent one, a sort of cushion.

3d. Above the valves, the vein exhibits a dilatation
which produces a depression on the interior and a pro-
jection on the exterior of the vessel. This arrangement,
in some cases, gives rise to knots, which are only seen
at the places where the valves are.

Ath. Besides the two membranous layers which, it is
said, form the valves, though they can in no way be sepa-
rated, fibres appear to enter into the composition of these
folds; at least, by examining them upon one of their
faces, white, interlaced filaments can often be distinguished.
Sometimes also the valves are perforated and formed by
an areolar texture.

5th. Perrault has established many species of valves
according to the form which they affeet. The only real
difference in this respect is, that in the great veins they
are very broad, and the curve which they describe small,
whilst in the small ones their want of breadth renders
this curve more evident. The valves are also broader at
the angles of union of the branches with the trunks.
This is independent of the state of contraction or dilata-
tion of the veins, which has an influence upon the size of
the valves, aS has been seen above.

VASCULAR SYSTEM WITH BLACK BLOOD. 107

Contractility of the Veins.

Page 415.—* The question,” (viz. whether the veins
are ‘irritable,) ‘“‘is not, then, fully settled, though I in-
cline much more to the belief that there is no venous irri-
tability.”’

Whatever may be the name under which we would
wish to designate the contractile force of the venous tex-
ture, we cannot refuse to admit that this texture pos-
sesses, during life, a property very different from all those
which are found in it after death, and consequently one
essentially vital. It is in virtue of this property that a
vein opened between two ligatures drives out from a dis-
tance the blood which it contains, whilst in the same ex-
periment made upon the dead body, the blood only oozes,
the effect alone of the elastic spring of the parietes. The
contractility of texture, in the sense which Bichat gives
to this word, cannot be the cause of this phenomenon,
since it exists after death as well as during life. If we
compress in a living animal the principal artery of a limb,
taking care to keep the limb in a horizontal position,
we shall see the sub-cutaneous veins gradually contract,
though the circulation may be suspended in the artery, and
empty themselves of all the blood which they contained
at the moment of the experiment. In the dead body, the
veins do not contract thus upon the blood they contain ;
their size depends always upon the quantity of this fluid
which remains in. them at the instant of death. More-
over, itis with this contraction as with that of the arterial
texture, it cannot be referred to any of the forces which
preside over the other kinds of contraction. The galvanic

108 ADDITIONS TO THE

stimulus appears to be capable of producing it, though
this has been denied.

Verschuir calls this contractile faculty of the venous
texture irritability ; Whytt gives it the name of vibra-
tory motion of the veins; Kramp designates it simply
under that of wtal force of the veins, and others refer it
to tone. I shall not decide which of these denominations
is preferable ; I would merely observe, that there is in the
venous motions during life something besides the effect
of the elasticity of inanimate matter.

‘

Venous Circulation.

Page 420.—* The blood is evidently beyond the influ-
ence of the heart when it arrives in the veins.”

This opinion is diametrically opposed to that of Harvey
and the mechanicians of his time, which some modern
physiologists have adopted. They consider the heart as
the sole agent of circulation, venous as well as arterial ;
Harvey compared it to a suction and forcing pump, which
on the one hand attracts the venous blood, and on the
other sends out the arterial. There is no doubt exag-
geration in this manner of considering it, though it would
be wrong wholly to reject the influence of the heart
upon the motion of the blood in the veins, The capil-
lary and venous action are the principal causes of this
motion; but the contraction of the ventricles should
be enumerated among .the secondary causes. One fact
will be sufficient to prove this. Open a vein and observe
the jet of blood which flows from it; at the end of some
time, this jet will be no longer uniform, it will be evi-
dently raised, and the blood will come out quicker at

VASCULAR SYSTEM WITH BLACK BLOOD. 109

each contraction of the ventricles. This influence is then
real, though much less evident than in the arteries.

Development of the Venous System.

Page 425.—‘ The veins have in the foetus an arrange-
ment inverse of that of the arteries; they are in propor-
tion much less deyeloped.’’

By applying to man the labours of Haller, Pander and
others, upon the development of the blood vessels of the
chick, it would follow from it that a part of the venous
system is earlier developed than the arterial system. The
first vessels that are discovered are the small branches of
the vein of the yolk, or the umbilico-mesenteric. This
vein itself, as well as the vena porta, is distinct when the
aorta hardly exists. . J. F. Meckel thinks nevertheless
that, from the arrangement of the sanguineous system in
some monstrous foetuses, and the manner in which this
system is complicated in the scale of beings, it would be
possible that the aorta should be formed in man at the
same time as the first veins, or even before them. If so,
this artery must exist before the heart, and communicate
directly with the vena porta before the formation of this
viscus. With this exception only in regard to the um-
bilico-mesenteric vessels, the veins in general are not
developed till after the corresponding arteries. As it
regards the development of the pulmonary artery, what

I have said in the vascular system with red blood may
be seen.

110 | ADDITIONS To THE

MORBID ANATOMY OF THE VASCULAR SYSTEM WITH
BLACK BLOOD.

I, Alteration in the external forms,

The veins, like the arteries, experience total or partial
dilatations ; this is what constitutes varices. The fre-
quency of this affection in the inferior extremities is well
known ; the reason of it has been given above. Itis also
quite often met with in the veins of the rectum, the blad-
der and genital organs, and in the sub-cutaneous veins
_ of the anterior parietes of the abdomen. The deep-seated
veins are not exempt from it, though they are much more
rarely affected than the superficial ones. Morgagni has
found the azygos vein considerably dilated ; the jugulars
and the crural sometimes become varicose. In some
cases, the whole venous system exhibits a very evident
increase. Puschett, who has recently published in Ger-
many a very extensive treatise on the diseases of the
veins, has insisted very much on this general dilatation,
which, in his opinion, performs an important part in a
great number of diseases. The dilatation may, not as we
have seen, be confined to a single vein, but extend to all
its divisions. The increase of size takes place then not
only in the transverse direction; the veins form curves
which are evidently owing to their increase in length.
Finally there are dilatations still more limited which
affect but a part of the circumference of the vessel.

The state opposite to the preceding, or the diminution
of capacity of the venous system, is by no means so
common. Yet it isseen under some circumstances, either
in the whole system, or only in some yeins in particular.

<= *
f

YASCULAR-SYSTEM WITH BLACK BLOOD. 111

This diminution can extend even to obliteration. There
are examples of the spontaneous obliteration of the venous
trunks themselves, as of the yene cave, jugulars, &c.

Il. @lterations in the Organization.

The inflammation of the veins takes place under many
circumstances. ist. It has been seen to extend a greater
or less distance after the operation of blood-letting. It is
always on the side of the heart that it is propagated in
this case, and never on that of the capillary vessels.*
Death even may be the consequenee of if. 2d. Tying
the veins, which has been sometimes done in amputations

vhas been followed by inflammation, which, as in the pre-
ceding case, extends towards the heart fora greater or less
distance., 3d. Tying the umbilical cord appears to have
produced the same effect. Meckel the elder, and Osian-
der have related examples of it. 4th. Veins affected with
varices and tied above the disease have also exhibited this
phenomenon. 5th. In very extensive phlegmonous in-
flammations, in those, for example, which come after par-
turition, in the abscesses and gangrene which succeed
them, the veins are often found more or less inflamed on
the exterior as well as the interior. This inflammation
sometimes extends far beyond the diseased part.

There is no vein which does not sometimes exhibit
traces of inflammation, from some of the causes that we
have just pointed out. The disorders produced by this
affection are, a redness more or less considerable on the
internal membrane, with a thickening of the two other
coats ; purulent collections of different kinds around the

* This rule however is not without exceptions. Abernethy has seen
the vein inflame below, almost to the wrist, after bleeding in the arm,
and remain sound aboye, that is to say, on the side of the heart.

112 ADDITIONS TO THE

vessel or even in its internal cavity, fibrous concretions
which obstruct this cavity more or less, sometimes even
the complete obliteration of the vein, in some cases a
remarkable hardness, and at other times ulcerations ; such
are the principal disorders to which this affection gives
rise.

It becomes salutary, on the contrary, when, as after
venesection, it is limited to the lips of the wound, and
does not extend beyond the degree necessary for its ad-
hesion. Every one knows that these punctures heal with
the greatest ease; it is also known that at the end of
twenty-four hours the means of union is still not very
firm, that it can even be broken by a moderate effort, and
that it is not till afterwards that there is a real cicatrix. .
The mechanism of the union is here the same as in
wounds of the other textures, whilst as it regards the
arteries, this union has hitherto been only observed upon
animals. If we may credit Mr. Travers, the internal
membrane of the veins does not partake of their adhe-
sive inflammation.

The same author believes, that in the obliteration of
the veins which follows their transverse division, it is not
the adhesion of the internal membrane, but the thicken-
ing of the parietes, which closes the cavity of the vessel.
His observations upon this subject should be repeated.

_ Wounds produced by an external cause resemble spon-
taneous ruptures.. Morgagni cites a case of this kind, in
which the azygos vein exhibited an oval opening in a
woman who died of phthisis. The blood was effused in
the thorax ; the vein, though partly flattened, had still
the size of the vena cava. Convulsive motions have ap-
peared sometimes to be the cause of these ruptures.

Wounds made in the parietes of the veins may affect
at the same time an artery which is united to them ; if,

/

VASCULAR SYSTEM WITH BLACK BLOOD. 113

in this case, the external wound cicatrizes, the opening of
communication subsisting between the artery and the
vein, there will result from it the disease described under
the name of aneurismal variz, in which the blood, pass-
ing from the artery to the vein at each contraction of the
ventricle, distends this last and produces in it a pulsatory
motion analogous to that of the arteries. Sometimes
there is merely a round opening, formed of the corres-
ponding parietes of the two vessels ; sometimes there is a
consecutive false aneurism, which is found between the
artery and the vein. It is in this last case that the dis-
ease deserves the name of varicose aneurism. ‘The bend
of the elbow is the most frequent seat of this affection, of
which various examples are found in authors, particularly
in the work of Hodgson on the Diseases of the Arteries.
Bichat has already remarked how rare osseous trans-
formations are in the vascular system with black blood ;
it is even one of the characters which he has given to the
common membrane which lines the whole interior of this
system. Yet this membrane is not entirely exempt from
them. Morgagni found in a young girl the sigmoid
valves of the pulmonary artery partly cartilaginous and
already exhibiting the commencement of ossification.
M. Corvisart has many times met with this alteration in
these valves, as well as in the tricuspid. The veins them-
selves are susceptible of ossification in old people, espe-
cially on the side where they touch an artery. There is
sometimes found in the veins small, hard, round bodies,
which might be taken at first sight for osseous produc-
tions. Some have even supposed that they are formed at
first in the parietes of the veins; others have said that it
was in the substance of the valves ; Hodgson thinks that
their primitive seat is on the exterior of the vein. These
bodies, which I have many times had occasion to examine,
15

114 ADDITIONS, &c.

have appeared to me to be real concretions, phlebolithes.
They are usually found in lateral dilatations in which
the blood is stagnant ; there is cbserved in their structure
nothing which resembles the osseous texture ; they seem
to be formed on the contrary of layers superadded to each
other, and have around them a very evident, coagulum.
They are found also of different degrees of consistence.
The veins which exhibit this alteration the most frequently
are those in which the course of the blood is the most ex-
posed to being retarded; thus it is very common in veins
which occupy the interior of the pelvis, the neighbour-
hood.of the arms, &c.

The venous texture has not any morbid affection which
is peculiar to it; it partakes of those of the other organs.

IIL. Alterations in the Development.

Are varieties in the situation, origin and distribution of
the veins more frequent than those of the arteries, as
Haller thought ? Meckel maintains the contrary, and that
the veins seem to have more varieties, only because their
number is greater. There is perhaps exaggeration on
both sides; yet it is evident that in the great trunks
the arrangement is much more constant in the veins than
in the arteries. .

There are veins in all parts as there are arteries. The
following is a proof of it; a false membrane, which was
found in the tunica arachnoides, and adhered to the
serous membrane only by one of its edges, at the superior
longitudinal sinus, and was entirely free elsewhere, was
injected with mercury, which enabled me to see veins
going to this sinus,

ADDITIONS
TO THE

CAPILLARY eccmamiaai

Continuation of the Arteries with the Veins, the
Exhalants, §c.

Page 19, vol. 2d.—*‘ It has been asked, if there was
any thing intermediate between the arteries and the
veins, inspection proves that the capillary system alone
is there.”’

It was formerly thought, in fact even since the beautiful
discovery of Harvey of the circulation of the blood, that
there was a texture intermediate between the last extremi-
ties of the arteries and the first branches of the veins.
This opinion was founded on the fact that oftentimes in
injections, the substance pushed into the arteries, instead of
returning directly by the veins, seems at first to be infil-
trated in the surrounding cellular texture. It was after-
wards perceived, that this infiltration was accidental, that

116 ADDITIONS TO THE

certain substances only, a solution of glue for example,
were capable of infiltrating, whilst others do not exhibit
this phenomenon. The existence of an intermediate tex-
ture was then rejected, especially as no one had seen this
texture. Finally, Malpighi appears to have been the first
who proved by microscopical examination, the direct con-
tinuation of the arteries with the veins, so well demon-
strated since by the experiments of Spallanzani and espe-
cially of Leuwenhock. At the present day any one may
see this continuation who will take the trouble ; for this
purpose, the transparent parts of animals are chosen, as
the mesentery of frogs, the tail and limbs of tadpoles, that
of fishes, &c. Injections driven through the arteries not
only return. by the veins, but the reverse also takes place,
if the valves do not prevent it.

The continuation of the arteries in the exhalant vessels
~ eannot exist unless these vessels really exist ; now, we
shall see hereafter that this point is still very obscure.
The communication with the excretories is not demon-
strated as it regards all the glands; there are some in
which injections have not passed from the arteries into
those tubes; the microscope has not yet shown us the
continuation of these two orders of vessels ; we know not,
if in the glands even in which they evidently communi-
cate, there be not an intermediate substance.

The last extremities of the arteries communicate also,
according to some, with the lymphatics, at the origin of
these last; this will be examined under the absorbent
system.

Erectile Texture.

Page 33.—‘‘ The spleen, the corpus cavernosum, in-
stead of presenting, like the serous surfaces, a vascular

i

CAPILLARY SYSTEMS, 117

net-work in which the blood oscillates in different direc-
tions, according to the motion it receives, exhibit only |
spongy, cancellated textures, whose nature is but little
known in which the blood appears often to stagnate, in-
stead of moving,”’ &c.

The arrangement of the capillary system in these
spongy textures has been very well described by many
modern anatomists... The corpus cavernosum has been
the particular subject of their researches. It might be
thought at first view, that it is a cellular or spongy tex-
ture infiltrated with blood ; when it is cut into, this fluid
flows from it and seems to come out of the small open
spaces and not immediately from the vessels...It is this
which deceived Haller and the anatomists who followed.
him, and made them believe that the blood was poured
out by the arteries in the interstices of the lamine and
fibres of the corpus cavernosum, from which it was taken
up by the veins.* But if on the one hand, the arteries
are injected, they are seen to terminate by very delicate
ramifications which go precisely as in the other parts ;
and by injecting the veins, on the other, we easily per-
ceive, Ist, that they are much dilated at their origin ; 2d,
that the species of enlargements which they occasion
have very numerous anastomoses, like the capillary sys-
tem of which they make a part. It follows hence that
these vessels appear, as it were, filled with openings,
which makes them resemble meshes communicating
together. The erectile texture of the corpus cavernosum
is then formed of small arteries and veins interlaced like

*Such was the opinion of Bichat himself, an opinion by no means
admissible, and which is abundantly refuted by what is here said of
the structure of the corpora cavernosa.

118 ADDITIONS TO THE

the capillary net-work ; all the difference is that here
the venous branches are more developed and dilated in a
particular manner. These enlargements are so unlike
cells, that they are only continued with the veins, and
the internal membrane of these vessels is found in them.

Besides, this manner of describing the erectile texture
is not new; -Vesalius, Ingrassias and Malpighi had seen
imperfectly its true arrangement. John Hunter has said
positively that it was formed only of vessels. Duvernoy
had the same idea from the dissection of the penis of the
elephant. In our time Mess. Cuvier, Ribes and others
in France, Mascagni, Paul Farnése and Moreschi in
Italy, and Tieddmann in Germany have perfectly demon-
strated this fact, both in man and various other animals.

In ereetion, the blood is accumulated in this texture as
Swammerdam is convinced; but we know not the cause
of it. Duvyernoy attributed this phenomenon to a contrac-
tion of the veins. Others have said that it was owing to
the entrance of the blood in greater quantity by the
arteries; it remains to be explained by this hypothesis,
why this afflux exists. Some have pretended that it was a
vital expansion of this texture, and that the accumulation
of blood was only secondary.

There are some parts whose structure resembles that of
the corpus cavernosum, or which are susceptible of a sort
of erection more or less similar to itsown. This appears
to be the case with the spleen as to structure, and even
as to phenomena; in fact, this viscus exhibits a real mo-~
tion of expansion and contraction, 1st, in experiments 5
when in a living animal, the course of the blood in the
splenic vein is stopped, the spleen swells ; it contracts as
soon as the circulation is reestablished ; 2d, in diseases ;
the paroxysms of intermittent fever are accompanied with
an evident enlargement of this organ, which goes off when

_ CAPILLARY SYSTEMS. 7?

the paroxysm is gone; 3d, it appears that the same thing
takes place during digestion. But it is especially to the
spongy texture of the urethra, the corpus cavernosum of
the clitoris, the nipple and the vascular texture of the
nymphe, that the name of erectile texture can be applied. —
The motions of the iris have been explained by supposing
it formed of this texture... The lips exhibit something
_ analogous. Everywhere, moreover, the arrangement of
the venous system seems to indicate, to a certain extent,
the presence of a sort of erectile texture, as has been
remarked by M. Chaussier. Injections show the veins
everywhere very evident at their origin, and giving rise
to net-works with such fine meshes that they might be
taken for the cells of a spongy xt inl part
of the fingers exhibits this arrangem in evident
manner.

Capillary Chrome.

Page 36.—“ The whole doctrine of the mechanicians
rested, as we know, upon the great extent which they
gave to the movements of the heart.’”

What we have said of the venous circulation applies
also to that of the capillaries ; the experiment which we
have cited proves the influence of the heart upon this last
as upon the first. Further, if in this experiment, the
artery is compressed, the jet of blood which comes from
the vein lessens and becomes less rapid. Then by sus
pending for a moment the action of the heart in relation
to the vein, we subtract one of the causes which deter-
mined the bleod to flow out. Now, what are these
causes? The same, nearly, as those which produce the
capillary circulation. Then, there are recognized as causes

120 ADDITIONS TO THE

of the capillary circulation, 1st, the peculiar action of the
capillary net-works ; 2d, the action of the heart. We
should never lose sight of the fact, that the heart wad
wiiinep this circulation in its own way.

I

MORBID ANATOMY OF THE CAPILLARY SYSTEM.

1% Alterations in the external forms.

The ¢ y wessels appear to increase in size under
two a ‘cumstances ; 1st, when the course of the
blood is, found interrupted in an arterial or yenous trunk ;
2d, when this fldithis accumulated in a part from the irri-
tation which it has experienced. _

After the ligature of the artery of a limb, there takes
place, as is well known, very important changes in the
circulation of this limb. All the blood which passed
through the tied artery flows back at first towards the
eapillary extremities of the collateral branches situated
above, and thus arrives, by means of the numerous anas-
tomoses of the capillary system, to the branches situated
below the tied point. The circulation is then carried on
in a circumscribed space, almost exclusively by the capil-
lary vessels, which are dilated in proportion. Injections
made upon the dead body show at this period an innume-
rable quantity of these vessels, many of which become
apparent only because the blood passes through them in-
stead of the serous fluids which they contained. In the
living animal, this sudden passage of a great quantity of
blood through the capillary system occasions an increase

CAPILLARY SYSTEMS. 121

of temperature and often even a redness of the skin, after-
wards one or more of these vessels become considerably
larger than the others, which return to their original size ;
the phenomena pointed out gradually disappear. There
usually exists then two or three great collateral branches
dilated, which reestablish the circulation in the limb. »

The spontaneous obliteration of the arteries is followed,
like their ligature, by the reestablishment of the circula-
tion by means of anastomoses. The same phenomena
‘take place in regard to the veins ; there is, as for the arte-
ries, an increase of the capillary net-works at a certain
period. It is necessary moreover, to distinguish this —
increase of the capillaries, from that which takes place in
the anastomosing branches’ of a -

considerable size,
and which have been noticed elsewhere. bi

IJ. Alterations in the Orgtinization.

The capillaries, unknown in their structure, are also
unknown in the alterations of their texture. Contusion
seems to weaken their parietes; at least they are often,
in this case, enormously distended by the blood; concus-
sion appears to act in the same way. The capillaries are
frequently ruptured, hence the various species of ecchy-
mosis, sanguineous infiltration, &e. These vessels, divid-
ed in wounds, furnish at first blood, then venous fluids,
_and then a substance capable of steam, ete 2 which becomes ©
the base of the cicatrix.

Ill. Alterations in the Development.

Capillary net-works are produced preternaturally, Ist,
in the production of false membranes; 2d, in the forma-
tion of cicatrices. Stoll appears to have been. the first

who remarked that, in some cases, the membraneous lay-
16 ,

122 ADDITIONS TO THE

ers which cover the inflamed venous membranes contain
very evident vessels and are continued with those of the
venous membrane itself. John Hunter and M. Chaussier
have since made the same observation. Most authors
admit that these vessels are only an elongation of
those of the serous membrane. Mr. Home _ thinks
with John Hunter that they are developed in altogether
another way ; according to him, there is, Ist, a forma-
tion of small bladders containing only colourless or even
gaseous fluids in the beginning ; 2d, union of these blad-
ders and’ the production of a vascular net-work still desti-
tute of blood; 3d, finally anastomosing between the ves-
sels developed and those of the inflamed membrane, and
the we a the jlood into the first. Such appears to
be, in fact; the course of nature. If we fill with mercury,
at hazard, a false membrane which does not appear to con-
tain vessels, the metal is distributed regularly through it,
and takes the form of ramified striz, similar to the rami-
fications in leaves; they are the vessels of the false mem-
brane, which existed before communicating with those of
the serous membrane. These vessels exhibit even after-
wards a diameter greater than that of the vessels of com-
munication, and a peculiar arrangement different from
theirs, as I have convinced myself by injection.

It is no doubt by an analogous mechanism that the
vessels of cicatrices are produced. Mr. Home and M.
Bauer have made microscopical experiments, which sup-
port this idea; I think it so much the more admissible,
as it accords perfectly with what we know of the forma-
tion of the vessels in the natural phlei of the
textures.

We find in a disease described by Bell under the name
of aneurism by anastomosis, by Frier and the German
authors under that telangiectasis, this variety of form of

f

CAPILLARY SYSTEMS. 123

capillary system which constitutes the erectile texture.
There is often a defect of conformation which the infant
has at birth ; such are most of those called nevi materni.
This disease appears usually under the form of a tumour,
the extent, size, colour, &c. of which vary. A whole
limb has been seen to be the seat of it. The texture
which forms these tumours resembles that of the corpus
cayernosum ; wheh injected by the arteries, it is not
always filled ; injections succeed much better by the
veins. The most ample details, however, on this subject
may be found in the work of Hodgson, which has been
already cited.

@

‘ADDITIONS

TO THE

EXHALANT SYSTEM. °

; aa
° aes
—

Arrangement of the Exhalant Vessels.

Page 69.—“ Let us reject then every opinion that dis-
regards anatomical observation, and let us endeavour by
this observation to ascertain what the exhalants are.”

It is evident, that if we are confined to strict observa-
tion, there are no more reasons in favour of the existence
of the exhalant vessels, admitted by Boerhaave and others,
than there is for that of the lateral pores imagined by Mas-
cagni. It is yery true that there exists white vessels,
as Vieussens and Boerhaave, at almost the same time,
thought, in this sense that the blood passes colourless
through many capillaries, which do not become visible
until their enlargement permits the red globules to enter

126 ADDITIONS TO THE EXHALANT SYSTEM.

them. The existence of these vessels is - especially well
established by an experiment of Bleuland ; this author
injected by the arteries of the intestine two substances
differently coloured, one of which, the thinnest, went
beyond the red vessels, into a net-work formed by vessels
of another order, which arise from the arteries and termi-
nate in the veins; ‘the coarser substance, on the contrary,
filled the arteries and the veins only as far as their direct
communication. Ruysch had admitted for a long time that
injections colour parts which are not naturally coloured.
“It is not correct, as has been pretended, that this difference

depends only on the quantity of the blood and not on

the nature of this fluid; for, when examined by a mi-
croscope,;ia single globule appears coloured.

But these white vessels, as injections show, terminate
like the red by continuing with the veins; nothing
proves that they go further. What are we taught in this
respect by the fact of the exhalations, that of nutrition
and that of transudation by the extremities of the arteries
in fine injections? That there are openings at these
extremities, by which the exhaled fluids, the materials of
nutrition and the matter even of injection escape. But
are these openings met with at the point of continuation
of the arteries with the veins, or are they the free ex-
tremities of an order of vessels which extend beyond ?
Here, as may easily be conceived, observation is arrested,

‘ADDITIONS |
TO THE

ABSORBENT SYSTEM.

|

Origin of the Absorbents.

Page 95.—*‘ It is not until they have run a certain
course, that these vessels are cognizable by our senses,
and that we can consequently study them in a general
manner.”’

The following are the only anatomical views we have
upon the arrangement of the lymphatics at their origin. —

lst. Cruikshank says that if we examine a small in-
testine during the process of digestion, we perceive
distinctly on its internal surface, the orifices of these
vessels, terminated like a watering-pot and filled with
a chylous matter which renders them more visible.
Hewson, Bleuland and Hedwig have made observations

128 ADDITIONS TO THE

analogous to this, which contradict, indeed, those of
Rudolphi and Alb: Meckel.

2d. By injecting the surface of the liver, and by after-
wards making the mercury pass, by pressing with the
finger, into the smallest vessels, we shall soon see it, as |
Mascagni has remarked, come out of these vessels by small
openings and appear on the surface of the serous mem-
brane. These openings, it is true, may be only inorganic
pores or even crevices, and not the natural orifices of the
absorbent vessels. 3

3d. We have seen, in the liver and testicle, the mercury
driven in at the ductus choledochus and vas deferens,
return by the lymphatic vessels, which seem to prove
that these last are open on the interior of these ducts. I
have myself had occasion to ascertain the correctness of
this fact. :

4th. As to the continuation of the lymphatics with
the extremities of the arteries, admitted by the ancients,
the fact is still doubtful. Most authors explain the
results of injections, by saying that they do not pass from
the arteries or the veins into the absorbent vessels, until
after being effused into the surrounding textures. Mas-
eagni admits, moreover, that the communication can be
established directly by the orifices of the lymphatic
vessels open on the interior of the arteries.

Venous Absorption.— Termination of the Absorbents.

Page 108.—‘‘ Here, as in so many other points,
physiology has need of great light.”—There are “‘ many
probabilities against and many in favour of venous ab-
sorption.”’

ABSORBENT SYSTEM. 129

Before the discovery of the lymphatic vessels, the
veins were generally considered as the only agents: of
absorption. Afterwards Hunter and Cruilfshank deprived —
them of this property, to give it exclusively to the absor-
bent vessels. At the present day, the idea of the ancients
isin part resumed, brought forward with new proofs by
Meyer, Messrs. Magendie, Ribes and other modern phy-
siologists. The following is one of the most conclusive
facts. Insulate to a certain extent the artery and vein
of a limb, taking care to cut all the other living connex-
ions which unite it to the trunk, and then introduce a
poisonous substance into the cellular texture, the animal
will immediately experience all the symptoms ‘of poison-
ing. Tiedemann and Gmelin have proved by many ex-
periments that all the substances recognizable by their
odour, colour or chemical composition, when taken into
the stomach, are found in the blood of the vena porta
with their peculiar characters. It must be admitted then,
either that the veins have absorbent orifices open upon all
the surfaces, or that they communicate soon after their
origin with the absorbent vessels. Abernethy has obsery-
ed something similar to this last arrangement ; he has seen
the vasa efferentia going off from a lymphatic gland in
order to go to a vein, and the injection passing from the
first to the second. °

Structure of the Lymphatic Glands.

Page 117.—“In the interior of these glands, these
branches,’’ (absorbents,) “‘ very tortuous, folded upon
themselves in different ways, occupy a great part of the
peculiar texture of these organs which many thought in

consequence were nothing but an interlacing of the ab-
17

1360 ADDITIONS TO THE

sorbents ; an idea that 1s not proved, since this texture
is not yet well known.”
ae

This idea, viz. that the lymphatic glands are nothing
but the interlacing of the absorbents, is that of Mascagni
who regards them as entirely formed of vessels. Gordon
coincides in this opinion, which appears in fact the most
probable, from the considerations we are aboutto offer.

There are, as may be seen, two orders of lymphatic
vessels in the glands of this name; some come to these
glands, the others go from them. These are the vasa
afferentia and efferentia ; they are distinguished by
their situation and especially by the direction of their
valves ; those of the first have their loose edge nearer
than the other to the gland; it is the reverse in the
second. ‘The number of these vessels varies; they are
found-from one to thirty on each side. There are, in
general, fewer of the efferentia than the afferentia,
sometimes as many, rarely more. In order to see ad-
vantageously the arrangement of these vessels in the
peculiar substance of the gland, it can be injected on its
surface with mercury, or in its interior with a substance
capable of becoming solid. Ist. If the surface be inject-
ed, either through the vasa afferentia or efferentia, it
exhibits on the one part, divisions ramified ad infinitum,
and forming, as it has been said, two opposite capillary
systems ; and on the other, branches dilated, enlarged
and anastomosing a great number of times, and forming,
like the preceding, net-works intermediate to the two
orders of vessels and belonging to both. 2d. The follow-
ing arrangement is found in the interior; the vessels,
filled with wax, appear even to communicate in two
ways, at first by the capillary extremities similar to those,
which, in the sanguineous system, terminate the arteries

f j
ABSORBENT SYSTEM. 131

and commence the veins, and moreover by enlargements
which cannot better be compared than to the analogous
enlargements which surmount the veins in the erectile
textures. It is in these enlargements that is contained
that whitish, thick matter, which Bichat and Haller place
in peculiar cells, and which is found more abundant in
children. :

All the glands of any size exhibit in an evident manner
the structure we have just pointed out; it is distinguished
even in many of the small ones, though it is less ap-
parent in them. There is but very little cellular tex-
ture in these glands, and it is very delicate if we except
the fibro-cellular membrane which surrounds them.
Their veins are in very considerable number, especially
in this membrane. Mascagni, Walter and others have
not been able to trace nerves in them.

Properties of the Absorbents.—Sensible Organic Con-
tractility. |

Page 120.—‘‘ The sensible organic contractility is
then at least doubtful in them, if it exists it is very ob-
scure and at most to be compared to that of the dartos
muscle.”

Schreger has seen the absorbents in many experiments,
contract under the influence of irritating agents. Not
only the concentrated acids, but also the butter of anti-
mony, alkohol and hot water, which we cannot suspect
of acting by the horny hardening, have produced this
effect. The action of cold water is often sufficient to
obtain the same result. Mechanical irritations have been
followed by alternate contractions and dilatations.. Under.
all these circumstances, the contraction. is propagated

132 ADDITIONS TO THE

always beyond the point touched, to a certain extent.
These phenomena, which are very striking during life,
' are also observed after death ; they continue even more
than those of museular irritability. If we add to this
that the thoracic duct is often, after death, broad and
flattened, though empty, whilst during life it is almost
always found contracted and hardly visible, we must
admit that the lymphatic vessels have a power of vital
contraction different from that which they possess after
death. It must be by this power that they contract and
empty themselves more or less completely when opened
between two ligatures; and in fact Tiedemann has ob-
served that this phenomenon, very evident during life,
in the thoracic duct and some other trunks, which then
empty themselves by a real jet, is very slight after death.

MORBID ANATOMY OF THE ABSORBENT SYSTEM.

I. Alterations in the External Forms.

The absorbents appear to be able to be dilated preter-
naturally. Some authors consider as dilatations of this
kind the species of hydatids that are observed especially
on the plexus choroides, in which they are arranged in a
line, united to each other by filaments.

Il. Alterations in the Organization.

Inflammation of the lymphatic vessels is followed, like
that of the veins, by suppuration, albuminous effusion,

f

ABSORBENT SYSTEM. 133

obliteration, &c. It has been already discussed as well
as that of the glands. The wounds of these parts heal in ©
general quite early ; it is not known if it be with an ob-
literation of the vessel; the cellular texture no doubt
contributes much to the process of reunion. This process
is sometimes very slow in the glands; thus it is often
preferred to remove them in operations, for fear that their
swelling would separate the edges of the wound and re-
tard the progress of cicatrization. Ruptures, analogous
to those which take place in the veins, have been seen in
the absorbents ; Assalini and Th. Bartholin relate examples
of them as it respects the thoracic duct.

The lymphatic glands are frequently the seat of the
transformation to bone, even at an age not greatly ad-
vanced. Their ossification has commonly taken place in
one part only of their extent. The frequency of the
tubercular disease of these organs is known; this is not
the place to describe this affection.

Ill. Alterations in the Development.

The anatomical varieties are very numerous in the

lymphatic as in the sanguineous system, besides those. °

which are purely accidental and which depend on the
kind of death, the previous disease, &c. These varieties
extend to the principal trunks as well as to the secondary
branches, to the glands as well as to the vessels. Thus
the thoracic duct is sometimes double, at least in a certain
part of its course; the two branches then often unite
again and thus enclose a kind of islands. Nothing is
more variable than the terminations of this canal at its
superior extremity: it is seen sometimes single, some-
times pouring the lymph by two or even three orifices
into the left sub-clavian vein, sometimes instead of open-

134 ADDITIONS TO THE ABSORBENT SYSTEM.

ing into this vein, it goes to the. jugular, the right sub-
clavian, or sends a branch to the vena azygos. The
glands do not vary less in their number and situation.

Inspection has not yet demonstrated lymphatic vessels
in the preternatural textures, such as cicatrices ; yet
absorption supposes them there, unless we prefer to have
recourse to that of the veins.

ADDITIONS
TO THE

OSSEOUS SYSTEM.

Intimate Structure of the Bones.

Page 160.—“ Let us consider the compact texture as
an assemblage of condensed fibres, not separated by lay-
ers, which we can only consider as imaginary.”’

Much has been written upon the intimate structure of
the bones, upon that of the compact texture in particular.
Malpighi admits that there are laminz and fibres in this
texture. Gagliardi has described minutely the. osseous
pins ; there seems to be some truth in his opinion, be-
cause we distinguish in fact in the bones, fibres which go
obliquely through their substance. Albinus, who is fol-
lowed in this by most modern anatomists, says that there
are only fibres in the osseous texture, parallel in the long
bones and radiated in the broad ones. Finally, if we may

136 ADDITIONS TO THE

believe Scarpa, there is nothing but small spaces in the
compact substance of the bones as in the spongy sub-
stance. Michel Medici has already combatted this idea
and thinks with the ancients that it is under the form of
laminz that the osseous texture is arranged.

By confining ourselves to the examination of the facts
alleged for and against these different opinions, we see, Ist,
that the existence of the fibres is by no means demon-
strated by the linear appearance which the osseous parti-
cles také at their development; in fact, this arrangement
does not continue long; in the broad bones, for example,
these pretended fibres, which then extend to the middle
of the substance of the bone are afterwards changed to an
areolar texture. There are however fibres in the bones,
as we see after having deprived them of their calcareous

‘matter. 2d. We may be convinced even that there are
lamin, by taking a long bone softened by an acid and
macerating it in water; its compact texture separates at
the end of some time into distinct laminz, united by fibres
which pass obliquely from one to the other. 3d. In this
experiment, the laminz often finally resolve into filaments
and the whole bone at the same time becomes spongy.
From this last fact, and from this, that in many diseases
of the bones, the compact substance. becomes spongy, as
well as from the circumstance, that it evidently takes this
appearance when, as Troja has done, a swelling of a long

bone is produced by introducing a foreign body into its,

medullary cavity. Scarpa concludes that the areolar struc-
ture alone exists in the bones of which we have spoken.
This conclusion is not accurate, since besides the areole
or small spaces, maceration shows in the bones laminx
and distinct fibres. It is true that, if this maceration be
very long continued, it converts the fibres themselves inte
a substance, as it were spongy, into a kind of mucus.

OSSEOUS SYSTEM. 137

It would seem then that it is by having had regard
enly to a small number of facts at a time, that each author
has explained, in his own way, the arrangement of the
osseous particles, and that we ought to admit in the bones
laminee, fibres, and areole or small spaces ; some are more
evident in the spongy texture, others are more developed
in the compact su bstance.

Arrangement of the Pores of the Compact Texture of
the Bones.

Page 160.—‘ Such is.the intimate juxta-position of the.
fibres of the compact texture, that they leave between
them only pores hardly sensible to the naked eye, but
which become so however with a glass and which the
medullary juice and vessels fill.”?

These pores are in many places real tubes which con-
tain marrow and blood-vessels. Havers, Monro, and,
latterly, Howship have described them. They are zi,
of an inch diameter. Most of them are parallel and
united by others whose direction is transverse or oblique
to the first.

Composition of the Osseous Texture.

Page 167.—** Upon this point,” (the composition of
the bones,) *‘ I refer to chemical books, especially to the
great work of Fourcroy.”

The human bones contain, according to M. Berzelius,
in 100 parts, Ist, 32,17 of gelatine and 1,13 of blood ves-
sels ; 2d, 51,04 of phosphate of lime, 11,30 of carbonate
of lime and 2,00 of the fluate of lime; 3d, 1,16 of the

18

138 ADDITIONS TO THE

phosphate of magnesia; 4th, 1,20 -of soda, hydro-chlorate
of soda and of water. | |

This analysis, hitherto the most complete, does not
agree entirely with those of other chemists. Thus,
Fourcroy and Vauquelin have recognized the existence
of the oxyds of iron, and magnesia silex and alumina in
the bones; on the contrary, they have not found fluoric
acid in them. Besides, the chemical composition of the
bones exhibits many differences not only according to
age, sex and individuals, but even in the different parts
of the body. The analysis of M. Berzelius was made
upon the femur of an adult. But the teeth evidently
contain much more earthy substance ; it even appears
that it is so with the petrous portion of the temporal
bone.. Various other examples of this kind are recorded
in the Anatomy of Monro, from the new researches of
J. Davy.

In an anatomical point of view, the bones are composed
essentially of a peculiar fibrous texture in the areole or
small spaces of which the calcareous substance is found
deposited. It is this texture that is obtained by treating
a bone with acids. The residuum of this operation is
not a cartilage, it has neither its whiteness, consistence
nor composition ; flexible like the ligaments, it very much
resembles the fibrous organs, from which it differs only in
this, that ebullition transforms it more easily to gelatine,
and that maceration softens it quicker. This texture con-
tains all the organic elements of the bone. We cannot
then consider it merely as gelatine, and say that the bones
are only a mixture of this substance and caleareous mat-
ter, as some authors have done. This expression is so
much the less proper, as the gelatine does not exist, as
far as it appears, completely formed in the bones, no
more than in the other animal matters, since it always

OSSEOUS SYSTEM. 139

requires the aid of ebullition to obtain it. Besides, if we
boil glue and calcareous matter, there results from it only
an unorganized compound, brittle and very different from
the osseous texture.

Veins of the Dipiloe.

Page 168.—« The accompanying veins of these arte-
ries” oie arteries of the spony texture) “ean hardly
be seen.”’

Very large, but insulated veins exist in some parts of
the texture of the cells. They are contained in peculiar
venous canals, which Hippocrates pointed out, and which
have since been very well described and injected by M.
Fleury. These veins form very numerous anastoinoses ;
they are especially apparent in the diploe of the bones
of the cranium but they are also found in the ossa ilii, in
the substance of the vertebre and in the extremities of
the long bones. Their size is greater in old people.

Development of the Osseous System. .

_ Page 206.—<‘ I would observe that the arteries, which
have so great a tendency to ossification, are not so evi-
dently gelatinous as many other substances which ossify
much less easily, as the tendons for example.”’

Duhamel, J. Hunter, Nesbith, Reichel, Stenff and many
others have made known many interesting facts: which
deserve to be recorded here. The natural development
of the bones only will be treated of, the preternatural
belongs to morbid anatomy.

140 ADDITIONS TO THE

The cartilaginous state is not always distinct. The
bones of the cranium really have no pre-existing cartilages.
We shall see that it is the same with regard to the middle
of the long bones.

The osseous state commences about the time stated by
Bichat. Stenff-has found the first rudiments of it at

forty days. I have seen some osseous points in embryos
of thirty days or near that period. The clavicle and the
jaws appear first; then successively and with some days
interval, the.humerus and the femur, the bones of the leg
and those of the fore-arm, the ribs, and vertebrae, the
bones of the cranium, &c. The sternum, the ossa wor-
miana, the patella, and the bones of the carpus are the
last that are ossified. This order is not however confined
to any rule ; thus all those, which it has been attempted
_ to establish, are for the most part false in their application.
The only one which has any real foundation is, that the
long bones generally precede the broad ones in their
development, though there are exceptions. But as to
the influence which some authors have given in this
respect to the proximity to the heart and to that of the
nervous system ; as to what others say of the more or less
early development of the bones according to the degree of
importance of their functions in man, or, as some think,
according to their more or less intimate connexion with
the phenomena of life in the different classes of animals,
nothing of all this is founded upon observation. |

Great changes take place in a cartilage which is con-
verted into bone. Vascular tubes, which could not
before be discovered in them, are developed. Colourless
in the beginning, and irregularly arranged, they are after-
wards ramified like the arteries, and traversed with blood.
The colour of this fluid manifests itself by degrees ; these
tubes however do not appear to contain it directly ; the

OSSEOUS SYSTEM. 14]

vessels of the cartilage injected seem rather merely to line '
their parietes ; this kind of vascular membrane, which
covers them, has even been considered as furnished to
secrete the osseous substance. These tubes are very well
seen in the short bones and the extremities of the long
ones. The osseous points, the development of which
follows closely that of the vessels, is at first merely an
union of filaments of extreme delicacy, which it is easy to
insulate by burning the cartilage; a kind of flake formed
of the caleareous matter is then obtained. As the ossifi-
cation advances the vascular canals are effaced; no more
traces of them are found as soon as the epiphyses become
solid. | 7
The action of the blood vessels is then increased in the
ossification of the cartilages. But do these last experience
any other change in their texture than that which results
from the deposition of an earthy substance ? or is the or-
ganic matter renewed, as some authors have thought ? It
is necessary in fact that the cartilage should undergo a
very great change, if it does not entirely disappear, in
order to become bone; for it contains, as we shall see
hereafter, scarcely any thing but water, cellular texture
and albumen, whilst the bones are formed of a fibrous
texture united to a saline substance. There is then a
very great difference between the composition of the first
and that of the second, and it cannot be said that the
bones are merely cartilages, with the addition of calca-
reous matter. Whatever may be the materials of ossifi-
cation, it is the arteries which bring them and pour them
out, either by exhalant extremities, as Bichat thinks, or
by lateral pores, which is the opinion of Walter. These
vessels do not perform the part, which Nesbith, Reichel
and W. Hunter attributed to them, of giving place by
their ossification to that of the cartilage. - The regular

142 ADDITIONS TO THE

lines which the bones exhibit in their development and
which have imposed upon these anatomists, by no means
follow the course of the blood vessels. We shall be still
less tempted to admit the hypothesis of Mascagni, who,
regarding the cartilages as entirely formed of lymphatic

vessels, supposes that in their ossification these vessels
are merely filled with caleareous matter.

In the long bones, the first osseous point appears from
the fortieth to the sixtieth day, a little sooner in the cla-
vicle. The small cylinder which it forms is then the
only solid part of the bone ; all the rest is still mucous.
It is not until from the sixtieth to the seventieth day that
the cartilages of the extremities appear ; when these last
are ossified, which does not take place till much later,
there is formed between them and the body of the bone
vascular canals similar to those which occupy their inte-
rior. There is then this remarkable difference between
the bodies and extremities of the long bones, that the
cartilage cannot be distinguished in the first as in the
second. In the middle, the osseous texture seems to be
formed entirely of one piece on the internal face of the
periosteum ; this texture is evidently cartilaginous in the
beginning at each extremity. 3

‘The ossification of the broad bones of the cranium
begins at about two months and a half. The osseous
points are at first scattered in the thickened mucous sub-
stance which represents the bone at this period. They
afterwards unite and take the form of irregular net-works;
it is not till later that they have that of osseous rays, still
covered with mucous substances on their two surfaces.
These rays disappear when the two compact laminz are-
formed ; they are changed into the texture of the cells.

The increase in length of the long bones takes place
near their extremities ; the middle has no part in it. An

OSSEOUS SYSTEM. 143

experiment, for which we are indebted to John Hunter,
proves this; if the body of one of these bones is perfo-
rated in two different places, and the animal is killed
some time after, the two openings are still at the same
distance from each other, though the bone may have
inereased in length. They would, on the contrary, be
further apart, if the growth took place in the whole extent
of the bone. Another fact confirms this. In the experi-
ments with madder, the colour appears in young animals
only in the space which separates each extremity from
the body of the bone; the rest is only red at the surface,
unless the animal has been fed for a long time with this
substance. Whilst a cartilaginous layer exists between
the body and the extremity, we consider that the growth
must take place at the expense of this cartilage. But
when it is once invaded, it must be admitted that there is
a deposition of osseous substance in this place, preceded
at most by the mucous state. The growth in length con-
tinues until the epiphyses are united to the body of the
bone, which takes place at about the age of twenty-one.
A delicate lamina of compact substance is at first inter-
posed between the body and the extremity ; this after-
wards disappears and the continuity becomes perfect.
The three species of bones grow in thickness much
beyond the term of their growth in length, as has been
already said. New layers are incessantly added to their
surface, as is shown by the colour of this surface from the
continued use of madder. If the use of this substance has
been alternately discontinued and resumed, the external
layers of the bone are alternately red and white ; whence
it must be concluded that they were formed during the
continuance of the experiment. The osseous substance is
produced there as in the preceding case without pre-exist-
ing cartilage, and perhaps by passing through the mucous

144 ADDITIONS TO THE

state ; but there is no interstitial deposition, as in com-
mon nutrition ; it is rather a sort of juxta-position. This
does not prevent the nutrition from taking place in the
bones the same way as in the other parts. The use
of madder for a considerable time, so as to obtain the
effect noticed by Bichat, is a proof of it. There are
also cases of preternatural growth, both in length and
thickness, which appears to arise from a real excess of
nutrition. |

_. At the same time the bones increase on the exterior,
their internal cavities enlarge; which occasions the
parietes of the medullary canal of the long bones to remain
in nearly the same proportion of thickness, as long as
their growth without and their diminution within coun-
terbalance each other. The bone gains on one side what
it loses on the other. It is not the same in old age. The
growth in thickness does not continue, and the internal
dilatation does ; there results from it an extreme delicacy
of the parietes of the medullary cavity. This cause is
one of those which render the bones of old people so
brittle. —

Some important changes take place in the osseous sys-
tem in old age. The broad bones diminish in general in
thickness. Their texture of the cells disappears and the
lamine of compact substance, which it kept separate,
come together; this is what is often seen in the parietal
prominences, in which it is so much the more striking as
these prominences are replaced by a depression. Some-
times the broad bones seem to have inereased in size,
because their texture is, if we may so say, rarefied ; deli-
cate laminze which pervade it, give it this appearance.
In the short bones, the external compact substance dimi-
nishes ; the areole of the spongy texture are on the con-
trary more evident. The long bones, besides what they

OSSEOUS SYSTEM. 145

lose of their thickness, seem also to experience a real
shortening. Finally, the change of composition which
takes place in the osseous texture takes from it much of
its elasticity. The bones of young subjects are flexible
to a certain extent; we see that at this age the long
bones bend and the broad ones yield under certain cir-

. cumstances. The-same causes will produce a fracture in

an adult, and for a stronger reason in an old person.

Second Dentition considered at the period of Cutting: ©

Page 219.— The second molar’’ (of the first denti-
tion) ‘‘ remains, as we have just said; it is the first of
the great ones’’ (of the second dentition.)

This is an evident contradiction, and must have escap-
ed Bichat from want of attention, or else it is a typo-
graphical error. It is said above that the first denti-
tion is composed of twenty-four teeth, of which four
molars in each jaw are cut towards the end of the second
year, and two other molars towards the age of four years.
It is then these last, or the third of the first dentition,
which form in the second the first large ones. The new
small molars take the place then of two teeth of the same.
nature, and not one alone. All the difference is, that
these new small molars are much less strong than the
teeth to which they succeed ; these resemble very much
the great molars.

19

146 ADDITIONS TO THE

MORBID ANATOMY OF THE OSSEOUS SYSTEM.-
I. Alierations in the External Forms.

Swelling of the bones is of many species. Ist. There
are tumours which seem to be deposited, as it were, on
the surface of the bone, so that this is perfectly sound
below ; such are most exostoses. This affection appears
_ to depend, in many cases, upon an inflammation of the
periosteum, in consequence of which this membrane is
detached, and secretes from its internal face a matter
which hardens and becomes confounded with the texture
of the bone; a sort of periostosis precedes the formation
of the osseous tumour. This is more or less voluminous
according to the extent of the inflammation. If the in-
flammation be circumscribed, there results from it what
are called nodes. These tumous are at first very dis-
tinct from the bone; afterwards maceration still detaches
them from it, and they are seen holding to the perios-
teum ; it is not until a long time that they appear to be
continued with the osseous texture ; it may then be seen
by the microscope that their vessels have not the same
arrangement as those of the rest of the bone, and do not
appear to be an elongation of them. When on the con-
trary the periosteum is inflamed for a great extent, enor-
mous lamine are produeed and give rise to the exostosis
called lumellated ; the bone is entire beneath these
laminee as in the other cases. 2d. Some exostoses have
their seat in the bone itself, and are produced by a de-
velopment or separation of,its most superficial lamine.
3d. The whole bone is stretched, becomes thinner and
is considerably dilated in spina ventosa. 4th. A real

OSSEOUS SYSTEM. 147

excess of nutrition is the cause of the increase of size,
when there is joined with it an increased density, or
when the density remains the same. This is what is
seen in exostoses that resemble ivory, and in some cases
in which the whole of the bone appears to have increas-
ed at once in thickness and consistence. To the same
cause may be referred the inerease in length which the
bones of scrophulous individuals sometimes undergo, that
in breadth which the bones ef the cranium, of the max-
illary sinus exhibit, in affections of these cavities. This
preternatural growth, which takes place in one or many
bones whilst the others do not partake of it, is not
effected by a mechanism analogous to that of the natural
development. There is here an interstitial deposition,
and not a formation of successive layers.

The increase in substance may be confined to the in-
crease of the density of the osseous texture. Enostosis
or internal ossification, in which the cavities of the bones
are effaced, is an example of this. The bones of rickety
subjects exhibit an analogous phenomenon, in the com-
pactness which their curvatures acquire on the coneave
side.

A. state opposite to the preceding is the species of
atrophy which this texture experiences when absorption
begins to destroy it, either on the interior, as takes place
in old age, or on the exterior, as has been sometimes
observed. According to Howship, to whom we are in-
debted for new researches upon the alterations of the
bony texture, the brittleness of the bones depends in
some cases, in syphilis, for example, upon an alteration
of this kind, a sort of internal absorption which transforms
the compact substance into a spongy texture. This
author distinguishes the brittleness which arises from
this cause from that which comes on, for example, from

148. ADDITIONS TO THE

scurvy and scrophula. This last is generally attributed
to a.defect in the proportion of the constituent elements
of the osseous texture ; but there appears to be besides
an alteration of the animal matter. i

The mollities ossium resembles brittleness very much;
both of them are often met with in the same bone. Mol-
lities is of two kinds. . One affects adults ; the bones
which are the seat: of it become soft and flexible, and are
bent by the effort of the muscles alone; in the dead body,
the scalpel cuts them easily. Desiccation and stewing
show that there is an evident predominance of gelatinous.
substance in these bones, which is also indicated by their
colour and appearance. The other species of 'mollities,
peculiar to children, differs from the preceding in many
respects. |

The bones, compressed by neighbouring tumours, ex-
perience various changes in their shape. These tumours
often also destroy them in part, perforate them and wear
them out to a greater or less extent. This happens
especially to those which are agitated by a pulsatory
motion, such as from aneurisms.

The connexions of the bones, or the articulations are
the seat of various affections which change more or less
the relations of the articular surfaces. The consolidation
of the immoveable articulations, luxations and ‘anchylosis
of the moveable articulations, exhibit examples of them.
Preternatural connexions sometimes take place between
the bones, as is seen in false articulations. Among these
last, some succeed to luxations, and deserve the name of
supplementary articulations ; others, which are in
consequence of fractures, which are formed by a single
bone divided into two fragments, are supernwmerary
articulations. 1st. When a luxated bone has not been
reduced, it may form for itself a new cavity in the place

OSSEOUS SYSTEM. : 149

it occupies. This cavity gradually acquires a suitable
depth; an edge, at first cartilaginous, and afterwards
osseous, is formed on its circumference; the cellular
texture thickened around the surface represents a sort
of fibrous capsule,* which contains a viscid fluid a little
less unctuous than the synovia. A fibro-cartilaginous
periosteum covers the new articular cavity: The old one
is altered and generally diminishes in extent. 2d. When
the two ends of a fractured bone do not unite, either on
account of their mobility, or from any other cause, the
new ‘relations which they contract resemble in some
measure an articulation, though in a less degree than in
the preceding case. Most often in fact, the fragments
hold together only by a kind of fibrous intermediate lines.
In some cases nevertheless their extremities become round
and are encrusted with cartilage, and a fibrous capsule
surrounds them. In some fractures of the neck of the
femur, the inferior extremity has been seen to form a
eavity in the superior; this case might be confounded
with the separation of the epiphysis.

Il. Alterations in the Organization.

But little is known of the effects of inflammation upon
the osseous texture. It is certain however that the bones
suppurate. They exhibit this phenomenon in caries, a
disease whose nature is still unknown, and which appears
to be in many cases a real necrosis. In what is called
white swelling, and which certainly comprehends very
different affections, something analogous is often seen in
the articular extremities. They are then the original

* Bichat speaks of this capsule under the synovial system, to which
it seemed to him to belong rather than to the fibrous system. The
fact is it has not always the same appearance in different cases.

150 ADDITIONS TO THE

eentre of the disease. The spongy substance is at first
softened, penetrated with vessels and then infiltrated with
a reddish serum. The bone afterwards suppurates, and
fistulas are formed in its interior, which are directed
sometimes towards the external compact substance, and
sometimes towards the articular cartilage. In this last
case, the cartilage, till then sound, is detached from the
bone, becomes thinner and is perforated with holes; and
what proves that the disease begins at the bone is, that
the opening remains smaller on the free surface of the
cartilage than on its adherent side, as has been well seen
by Messrs. Palletta and Brodie, who have described this
affection, and as I have myself ascertained.

Gangrene of the bones is necrosis. It is followed by
the same phenomena as that’of the soft parts, only it
requires a longer time for the inflammation, suppuration
and separation of the dead parts, which here take the
name of seguestra. But this necrosis varies more-
over from its extent, as well as from its seat. It is
usually the result of the destruction of the nourishing
vessels of the bone, from the detachment of the perios-
teum or the destruction of the medullary membrane.
When it is the medullary membrane which is injured,
the necrosis only affects the internal laminz of the bone ;
the sequestrum is then contained in the medullary canal,
and has the thickness of the bone to go through before
it can be thrown off. But in other cases, the periosteum
is inflamed at the same time and is separated from the
bone ; this is then affected with necrosis in its whole
thickness, and there take place all the phenomena de-
scribed in the article upon the medullary system; the
periosteum secretes a new bone, which surrounds the dead
one. Here this membrane must have remained uninjured,
_ for if it were destroyed there would be no regeneration.

OSSEOUS SYSTEM. 15}

It is without cause that Scarpa and others have denied
this regeneration, and have pretended that what has been
regarded as a new bone was always a part of the old one,
dilated by inflammation and which the necrosis had spared.
The sequestrum has precisely the form of the old bone;
all the prominences and the most superficial depressions
are found in it; the numerous specimens of this kind
that are in existerice leave no doubt upon the subject.
What has perhaps imposed upon the authors we have

_just mentioned is, that the dead. bone is worn on its

surface and covered with inequalities. ‘The new bone has
an irregular form, and resembles rather an exostosis or
a kind of vegetation, than a bone which existed originally.
Finally, in the broad bones, such as the scapula, this is
still more striking; there exists then two bones of new
formation, one external, the other internal, and the old
bone which is dead, is contained in the space between
the two. |

The separation of the periosteum and the denudation
of the bones, which is the result of it, are not always
followed by necrosis, when they take place only to a
certain extent. Ifthe bone’has not been much contused,
if the subject be young and the integuments be reapplied,
an immediate reunion is obtained by the effusion of a
coagulable matter. This matter exhibits at a certain
period, irregular osseous points, which have given origin
to the belief in insensible exfoliation; these points are
afterwards effaced.

Solutions of continuity of the bones, or fractures differ
according as there is at the same time a wound in the soft
parts, or these parts still cover the place of fracture. The,
phenomena are entirely different in the two cases. It is
only to fractures with denudation that must be applied all
that has been already said upon the formation of callus.

152 ADDITIONS TO THE

In these only arise the fleshy granulations which. after-
wards form the basis of the cicatrix, whether there has
been exfoliation by denudation or not. In the others,
there are the three periods that have been pointed out;
Ist, a period of exudation; 2d, a a of tumefaction ;
3d, a period of reunion.

First period. The osseous texture cannot be divided
without the flow of blood from the open vessels; thus
there is effused at first a certain quantity of this fluid
between the two fragments; this quantity is usually
inconsiderable, and the blood stops of itself at the end
of a short time. Another fluid succeeds it; this is of ‘a
serous nature and of a slightly viscid consistence. The
effused blood gradually loses its red colour. Reunion is
effected in the periosteum, the medullary membrane and
in all the other soft parts which have suffered by the
effect of the fracture alone.

Second Period. ~ These feanited soft parts, the perios-
teum in particular, inflame, swell and separate from the
bone ; hence a tumour which is visible externally. This
tumour is in great measure formed by a coagulable sub-
stance effused under the periosteum and between its in-
ternal laminz. Osseous points are formed in this sub-
stance and finally take entire possession of it; the carti-
laginous state is hardly sensible, and exists at the most
but in some points. For the want of periosteum, the
cellular texture becomes the seat of this ossification, as
has been seen by Macdonald. The medullary membrane
is also ossified. i

Third Period. Hitherto scarcely any thing has been
done in the bone itself; only the two ends are found
joined externally by a sort of clasp, and internally by a
plug which shuts up the medullary canal. But this union
- has only a slight degree of solidity; and if the bone be

OSSEOUS SYSTEM. 153

again subjected even to inconsiderable efforts, the callus
will yield or bend, and even break. The process: of
reunion is carried on in the fragments themsélves ; the
intermediate substance which filled the space between
them, hitherto fluid becomes gradually more consistent,
and is penetrated with vessels which are continued with
those of the periosteum and even of the bone. This
substance is not long in being ossified ; it is not known
precisely in what manner, though vessels have been
clearly seen to be developed in it. At the same time
that these phenomena take place, the external swelling
flattens down. Afterwards, the ossification of the perios-
teum disappears, the medullary canal is reproduced, and
things are restored to the state in which they were
before the fracture.

There is then in the reunion of fractures, as in wounds
of the soft parts, a vascular cicatrix, formed nearly by
the same mechanism. ‘The whole difference consists in
the changes which the surrounding parts undergo, and
which give place to the development of a_ provisional
bone, before the final callus is formed. Strike out the |
second period, and the mode of reunion of fractured
bones will not differ sensibly from that of the soft parts.

It is thus seen what should be thought of the opinions
so various, which authors have had upon the formation
of callus. Most are exclusive from having observed the
callus in one period of its development only. It is thus
that Duhamel, and after him Fougeroux and Pelletan,
have seen perfectly that the periosteum is ossified ; but
they attributed to it too much in supposing that it was
this which constituted the callus. Now this will ‘not
appear astonishing, when it is known, that Duhamel did
not pursue his experiments upon the callus, otherwise so
praiseworthy, beyond thirty or forty days. So ‘Boer-

20

154 ADDITIONS TO THE

haave, Haller and Dethleef found between the fragments
a lymphatic matter and were satisfied with this observa-
tion. Almost in our days, Hunter, Macdonald and
Howship have said that it is the effused blood, the colour-
ing matter of which is absorbed, which is afterwards
, organized to give birth to the callus. Others from the

example of Bordenave, have been deceived by what takes
place when the fracture is in eontact with the air, and
have thought that it was the same when the fragments —
were not exposed; Bichat himself did not avoid this
errour. Some, such as Troja and Camper, have approach-
ed nearer the truth, by adopting a mixed opinion... But
it is especially te modern anatomists that we are indebted
for. the knowledge of the facts which we have stated.
M. Dupuytren was one of the first who observed these
facts. We are indebted to Messrs. Breschet and Villermé
for a very extensive work upon this subject.

There are fractures in which no bony callus is formed,
but only a fibrous cicatrix which unites the two frag-
ments loosely. It is what is seen especially in those
bones which, like the patella, olecranon process and neck
of the femur, are very difficult to be kept perfectly fixed.
The motions of the fragments and their separation are in
fact the sole causes of this phenomenon, which was for-
merly considered as constant in these bones and dependant
on their structure, and which it has been attempted to
explain by a pretended dilution of the osseous juice, by
the absence of periosteum, &c. The same result is obtain-
ed, when ina living animal, a portion of a long bone is
cut out ; if the distance between the two ends be too great
for their extremities to unite by becoming thinner and
extending towards each other, the callus is in part fibrous
or fibro-cartilaginous. The opening made by a trephine
exhibits also this peculiarity ; when it is very hroad the

4

OSSEOUS SYSTEM. 155

eicatrix is completed by a fibrous portion. On the con-
trary, the reunion is immediate, even in bones which
were not thought capable of it, when the approximation
of the fragments has been exact for a proper time. I
have seen patellas thus united; dried and soaked in
spirits of turpentine for the purpose of rendering the
cicatrix transparent, as it would have done if it were
fibrous, they proved to be osseous in every part. These
cases are in truth very rare, because the separation is
almost inevitable, as it may come on not only at the
instant of the fracture, but as long as the intermediate
substance has any extensibility, the callus itself may
sometimes yield, and it requires at least two or three
months for the callus to acquire complete solidity, instead
of from fifty to sixty days as is commonly thought. This
termination of the fractures is precisely znalogous to what
takes place in the long bones, when their fragments are
continually moyed. There results from it a kind of false
articulation.

The bones are rarely affected with organic diseases ;
this point of their history has been hitherto neglected.
Yet the cancer of the bones has been described under the
name of osteo-sarcoma ; but much remains to be done to
classify all that has been designated under this name.
Sometimes a tubercular affection is met with in the bones.
They are also the seat of a kind of fleshy tumour, which
interrupts entirely their continuity, and the texture of
which is very like that of the cerebriform tumours, ex-
cept that it contains more blood-vessels. I have many
times seen these tumours in the clavicle.

Ill. Alterations in the Development.
The osseous system is subject to frequent defects of

conformation ; they are observed especially in the bones
of the cranium and in the sternum.

156 ADDITIONS TO THE OSSEOUS SYSTEM.

The osseous substance has a tendency to be produced
under many circumstances. There is scarcely any part
which is not ossified by the progress of age. The carti-
lages are in the first rank ; then come the fibro-cartilages
and the fibrous textures as it respects the frequency of
this ossification. The cellular texture is the most rarely
the seat of it. As to the arteries, there is in many cases
a sort of incrustation, rather than a real osseous trans-
formation. The venous, muscular and nervous systems
exhibit more rarely examples of it. The preternatural
productions are not exempt from this transformation ;
eysts wholly osseous are often found. The cartilaginous
state does not seem always to precede these ossifications.

‘ADDITIONS

TO THE

MEDULLARY SYSTEM.

|

Organization of the Medullary Membrane.

Page 231.—‘* To be convinced of its existence,”’ (the
medullary membrane,) ‘‘ expose the cylinder that it forms
to the intense action of heat; it contracts, has the horny
‘hardening immediately like all the solids, and thus _he-
comes more apparent.”

This experiment is made by sawing a long bone, and
then plunging it into boiling water ; the membrane sepa-
rates from the bone and adheres to the fat, which ena-
bles it to be better seen. The diluted mineral acids
may also be used, which produce the same effect.

This membrane when entirely detached from the bone,
resembles in some measure a cobweb; it is'pierced with

158 ADDITIONS TO THE

a multitude of holes. The basis of it is the cellular tex-
ture and vessels. The first is in small quantity and has
no other use than to support the vascular ramifications.
Among these last, some which are very well described by
Duverney, go outwards to the osseous texture; the others
go inwards, towards the elongations of this texture and
of the membrane itself. The principal artery of the
medullary canal is surrounded by absorbent vessels at its
entrance into this canal. An evident nervous plexus is
also observed about it, in the bones which are the nearest
the trunk.

Moreover, adipose vesicles of the same kind as those
of the cellular texture, though they may be a little less
distinct, contain the medulla and occupy the interior of
the medullary membrane, lodged in the cellular inter-
stices which this last contains ; we know not if they are
also found in the spongy texture of the extremities.
Authors have for a long time noticed that the medulla
is formed of small grains united into a cluster, as is seen
especially when it is recent and has not yet lost the con-
sistence which is peculiar to it. But it was believed that
these vesicles communicate with each other, as it was
then thought of the adipose texture. G. Hunter, Mas-
eagni and many others have seen that they are shut. The
description which they have given of them, both from
direct inspection and analogy, shows in them an arrange-
ment similar to that of the adipose texture. We shall
not advert again to this arrangement.

Sensibility of the Medullary Membrane.
Page 231.— The most acute pains are the result of

the action of the saw upon it’? (the medullary membrane)
‘in amputation.”’

f

MEDULLARY SYSTEM. le

This phenomenon is not constant; there is often no
pain in this case ; but we must not conclude from it, as it >
has been done, that the sensibility of the medullary mem-
brane does not exist. In amputations made upon man,
the pain caused by the division of the soft parts, and
especially of the skin, is so intense, that this less severe
one produced by the division of the medullary membrane,
which almost immediately succeeds it, is hardly felt.
But if, in a living animal, the operation is suspended after
the division of the soft parts, and resumed when the first
impression is in part dissipated, the sensation is acutely
perceived, and the animal utters distressing cries. The
sensibility of the marrow, already recognized by Duverney
and since denied, is then real.

Development.

Page 234,—“ This absence of the medullary fat in the
foetus, essentially distinguishes the marrow from the ordi-
nary fat, which, at this age, is already very abundant.”

The fat of the bones, in being wanting in the fetus,
resembles in this respect that of the deep parts in general,
which are then almost entirely destitute of it. Moreover,
there is not only no marrow at this age, but there is
no medullary membrane. Bithat did not wish to con-
sider this membrane as a new organ ; but it is evident that
nothing indicates its presence before ossification. After-
wards, when the medullary canal begins te be formed,
the nourishing artery fills it entirely ; it is not till an after
period that this artery is thrown out upon the parietes of
the cavity and that the medullary membrane exists.

_ The marrow becomes very abundant in old age, owing
to the enlargement of the medullary cavity. .

160 ADDITIONS TO THE

Functions.

Page 236.—‘ Who.does not know, that in diseases
of the articulations in which the synovia is altered and
vitiated, the marrow of the corresponding bones is almost
always in a perfectly sound state.’’

To the reasons for not admitting the production of the —
synovia by the transudation of the marrow through the
articular extremities, may be added those which Soemme-
ring has given, viz. that the marrow is the most abundant
precisely in the place the most remote from the extremi-
ties, and that children, who have no marrow, and whose
extremities are all cartilaginous, have not less of synovia
in their articulations. This last fluid is met with besides
in many places where the other evidently cannot pene-
trate, as around the tendons, in the burse mucose, either
natural or preternatural ; finally, there is a total difference
of properties and composition between it and the medul-
lary fat.

Various uses, not less hypothetical, have also been
attributed to the marrow. It has been thought to be well
adapted to give flexibility and tenacity to the bones ; this
was the opinion of Duverney ; but if it be recollected
that the bones of young subjects are the least susceptible
of breaking, and that those of old people, which contain
so much marrow, are on the contrary the least resisting,
much attention will not be paid to this opinion, which
rests only on a single fact; it is this, that the bones,
reduced by combustion to their calcareous matter, resume
in part their solidity when boiled in oil; but the same
thing takes place with every other substanee, with gela-
tine for example, and there is a great difference between

~ MEDULLARY SYSTEM. 161

a bone which combustion has destroyed in part, and that
which still contains all its principles.

The ancients said that the marrow served to nourish
the osseous texture ; but it is sufficient, that there are a
great number of bones destitute of medullary fat, to ren-
der this inadmissible. The medullary membrane _per-
forms on the interior of the bone the office of periosteum ;
it contains nourishing vessels, and it is in this way only
that it contributes to nutrition. As to the marrow, it
must have the same general uses as the fat; it is a kind
of aliment in reserve, one of the forms in which the
nutritive matter is clothed. It serves besides to fill the
void which without it would exist in the medullary canal.

Morbid Anatomy of the Medullary System.

The alterations of this system have not been sufficiently
studied to enable us to present a complete view of them.
We shall here confine ourselves to a mere sketch. ,

It is very probable, as Bichat says, that the medullary
membrane of the long bones is affected in syphilitic pains.
In fact, a slight percussion made on the surface of the
bone excites these pains, on account of the jar it commu-
nicates to the marrow. Besides, we are completely igno-
rant what kind of alteration this last experiences.

In amputations, the oily matter of the bones is absorbed
in the neighbourhood of the wound ; the medullary mem-
brane is covered with fleshy granulations, and contributes
to the formation of the cicatrix. What takes place after
fractures has already been noticed; a sort of hardened
plug fills the medullary canal; this canal is afterwards
reestablished, unless the union between the fragments be
not exact, as when they slide over each other. In necro-
ses which include the medullary canal, when the old bone

al

162 ADDITIONS TO THE MEDULLARY SYSTEM.

has been drawn out, there remains a reddish membrane
which lines the new one; but the marrow is not repro-
duced. 5

Spina ventosa is an affection peculiar to the marrow;
it is a true cancer of the medullary membrane, different
from the cancer of the bone and from that which affects
the periosteum, but analogous to these affections in its
nature. The disease has its seat usually near the extrem-
ities ; on the leg, it is towards the superior end, and on
the thigh, it is towards the inferior, that it most often
exists. It may happen that the osseous texture is at the
same time altered ; but frequently this texture is sound
and has only experienced a greater or less dilatation, a
simple extension. It is then found that the bone forms a
covering to the tumour, sometimes enormously dilated,
often perforated and traversed by vegetations of a cancer-
ous nature ; this is what I have many times pap occasion
to observe.

The medullary fat varies much in quantity according
to the state of corpulency ; but the medullary canal is
always full of a fluid which resembles the marrow more
or less. In fat subjects, the marrow has appeared to me
to contain, in eight parts, seven of oily and one of foreign
matter. This agrees with what has been stated by Gru-
tozmacher. In a phthisical subject, I have seen the fat
form only a quarter; the rest was a serous or albuminous
fluid similar to that of which Bichat speaks. It would
then be possible, that in extreme emaciation, there might
_ be hardly any fatty matter.

‘ADDITIONS

CARTILAGINOUS SYSTEM.

|

Peculiar Texture.

Page 243.— With a little attention we distinguish”
(in this texture) “ longitudinal fibres, which are crossed
by transverse and oblique ones.”’

It is very difficult to see these fibres distinctly ; every
thing appears to be homogeneous in a cartilage cut through,
as Bichat observes. The only thing which denotes organ-
ization in it is, that an oozing of serum takes place, at the
end of a short time, upon the divided surfaces, which
indicates that there were fluids in circulation in it. This
oozing is more abundant as the subject is younger.

Various facts seem to show that there is a peculiar ar-
rangement in the cartilaginous texture; on this subject

164 ADDITIONS TO THE

there are different opinions. Duhamel thought that this
texture was composed, in the cartilages of ossification, of
concentric laminz superadded to each other, from the
formation of the successive osseous layers which his
experiments with madder had demonstrated to him.
These experiments have been noticed elsewhere ; we have
seen what must be concluded from them in relation to
the growth of the bones.. They in no wise prove the
arrangement of which we are treating, since the layers
are only formed on the surface of the bone, when this is
once completely developed ; we find neither plates nor
layers of any kind in the pre-existing cartilage.

Hunter and Delassone say that the fibres of the carti-
lages of the moveable articulations are perpendicular for
_ the most.part, and implanted in the bones of these articu-
lations ; they compare the appearance which results from
it to the texture of velvet. The greater facility with
which these cartilages break in the direction of their
thickness, the perpendicular direction of the fibres which
is seen in them when they are cut in this direction, and
maceration, which, if sufficiently long continued, renders
these fibres distinct, are, it is said, the reasons upon which
this opinion is founded, which cannot be entirely rejected ;
for the structure which has just been described becomes
sometimes apparent in diseases. I shall say only in
regard to the second fact, that the traces, which the
instrument employed to make the section of the cartilage
leaves, have no doubt. been taken for fibres.

According to Hérissant, the cartilages of the ribs are
formed of lamin twisted into a spiral form, and it is to
this arrangement that they owe their elasticity. This
author cites maceration as a proof of what he advances.
His observations on this subject require confirmation.

;

CARTILAGINOUS SYSTEM. 165

Finally, some appear to have been deceived by the
changes which the cartilages undergo when they are on
the point of being ossified.. It is thus that Mascagni
admits in the costal cartilages lamine in the form of rays,
beeause he has found in the centre of these cartilages a
sort of marrow separating these lamine. But they exist
only in adults and in cartilages which have been exposed
to desiceation; now, the cartilaginous texture, taken at
this period, is not perfectly homogeneous ; its exterior, ©
more compact, dries quicker than-the interior, and cannot
contract, when this still tends to diminish in size; there
results from this, spaces which are produced in the centre.
We ought also to attribute to the commencement of ossifi-
cation, owing to the progress of age, the reddish and
areolar cavities which Morgagni and Portal have described
as inherent in the structure of the cartilages.

The membranous cartilages of the nose and the ear,
which will be noticed under the fibro-cartilaginous system,
have, according to Soemmering, distinct little fibres, when
they have been macerated a month.

Chemical Composition.

Page 244.—“ Ebullition upon the articular extremi-
ties, breaks it,’’? (the cartilaginous texture,) ‘‘ and raises
it by layers which it softens, and which finally it melts
almost completely.”

The cartilages of the sutures are likewise dissolved in
boiling water and furnish a sort of jelly, like the diarthro-
dial cartilages ; all the others resist ebullition, and do not
give out gelatine in this case unless they contain osseous
points. This accords with what is known at the present
day of the composition of the cartilages. Haller thought

166 ADDITIONS TO THE

that they were formed of water, gelatine, and an earthy
substance ; but modern chemists have obtained different
results. Mr. Hatchett has found in the cartilages albu-
men and the phosphate of lime. M. Chevreul has given
the analysis of the cartilaginous bones of the Squalus
Maximus; they contain, according to his researches,
mucus, oil, acetic acid and various salts. Finally, accord-
ing to J. Davy, there is in the cartilages 44,5 of albumen,
55,0 of water, and 0,5 of the phosphate of lime.

Moreover, this composition must vary at the different
periods of life, as well as the proportion of the constituent
principles. The eartilages of young subjects contain more
fluids, as may easily be proved by drying them compara-
tively with those of an adult.. They are reduced almost
to nothing in this experiment, whilst the second lose
much less of their size. We see besides in combustion,
that there is scarcely any ashes left of the first, whilst
the others give an abundant earthy residue.

oem
MORBID ANATOMY OF THE CARTILAGINOUS SYSTEM.
Il. Alterations in the External Forms.

_ The articular cartilages are sometimes swelled and soft-
ened in white swellings, at other times detached in part,
hanging in the articulation, and often destroyed to a
greater or less extent; this destruction, frequent in the
diseases of the articulations, may bring on anchylosis. In
some cases the articular cartilages seem to have entirely
disappeared, and there are only found osseous surfaces
like ivory; is the cartilaginous texture ossified in this
case as Bichat says, or has it been destroyed? It is diffi-

CARTILAGINOUS SYSTEM. 167

eult to determine this. These same cartilages exhibit
frequently after rheumatic affections and in consequence —
of chronic engorgements, species of floating fibres, loose
at their extremity ; it is these fibres which seem to favour
the opinion of Hunter and Delassone upon the structure
of the cartilages. The cartilaginous texture seems to be
decomposed in this case, unless this alteration be regarded
as the result of a partial erosion.

Il. Alterations in the Organization.

Inflammation has never been observed in the cartilages;
in no case are the vessels of these parts coloured with
blood ; white fluids alone appear to be capable of aceumu-
lating in them. Ulceration however, which does not
spare the articular cartilages, as we have just seen, is a
proof that inflammation may be developed in them.

Denudation and wounds, which everywhere else are
followed by inflammation, do not produce this effect in
the cartilages. When they are laid bare in a wound of
the soft parts, this reunites by adhesion or by cicatriza-
tion, according as the flap has been reapplied or not ;
but the cartilaginous texture does not participate in the
work of reunion, as J. Hunter and J. Bell have seen ; it
remains insulated, covered by the cicatrix, without in
any way adhering to it. When an articulation is opened
in a living animal, the cartilage does not inflame nor red-
den, whatever may be the duration of its exposure to the
contact of the air; only if the experiment is prolonged,
we see the synovial membrane, red at first in the other
part of it, inflame also over the cartilage, and the redness
of this membrane extends gradually towards the centre
of the cartilage. Yet broken cartilages reunite, as Auten-
rieth first discovered in the costal cartilages. Different

168 ADDITIONS TO THE

observers, Messrs. Magendie, Lobstein and myself have
recently confirmed this fact. But the part of the carti-
lages is purely passive in this case. When those of the
ribs are fractured, if the two ends remain opposite, an
osseous band is formed around them and keeps them in
contact; if, as is most common, the fragments have slid
upon each other, a band, at first fibrous, then cartilaginous
and osseous, holding to the perichondrium, fills the space

between them ; but in this case, as in the other, they are
merely contiguous. It is only in old age, when the car-
tilages are upon the point of ossifying, that they reunite,
like the bones, by a true intermediate callus.

Ulcers of the diarthrodial cartilages are sometimes the
seat of a process of separation which resembles, to a cer-
tain extent, that of the wounds of the soft parts. There
is then found cartilaginous portions newly formed in the
place of those which the erosion had destroyed. This
affection has been taken by some for an original defect of
conformation ; it is evidently only secondary.

The osseous transformation is the only one which the
eartilages experience ; but they experience it almost
necessarily with age, and almost without departing from
the natural order. Besides, we distinguish, in this re-
spect, two kinds of cartilages; one, merely temporary,
becomes ossified in the first year; the other, which con-
tinues a longer time, is called permanent, but only in
relation to the first, for the cartilages of this kind also
finally become ossified ; the cartilages of the moveable
articulations are perhaps the only exception. But their
ossification does not take place regularly nor at fixed
periods, like that of the temporary cartilages ; it may be
delayed to a very advanced age. Keil has seen the costal
cartilages not ossified in a man of a hundred and thirty
years; Harvey has made the same observation upon

CARTILAGINOUS SYSTEM. 169

another of a hundred and fifty-two. Besides, the mecha-
nism of ossification is the same for all the cartilages.

III. Alterations in the Development.

The cartilaginous system is subject to a small number
of defects of conformation ; the costal cartilages some-
times exhibit these irregularities.

The preternatural development of this system has
already been noticed ; we shall advert, in the synovial
system, to the foreign bodies of the articulations and to
the true mechanism of their formation. The cartilaginous
productions differ, like all the others, according as they
appear to be deposited, as it were, in the interstices of
the organs, or as they are owing to a transformation,
which one of them has undergone. Insulated cartila-
ginous masses have béen found in various parts. More
often still various organs become cartilaginous. M. Laen-
nec has met with this transformation in the urethra; I
have observed it in the vagina, in consequence of inver-
sion of the womb; I have also seen it in the prepuce, in
a case of phymosis.

22

ADDITIONS

7
|

“s TO THE

FIBROUS SYSTEM

Yellow Fibrous Texture..

Page 269.—* They appear”’ (the ligaments placed be-
tween the laminz of the vertebra) “‘ to contain much less
gelatine, and to be entirely different in their nature.”

These ligaments belong, in fact, to a division of the
fibrous system, confounded for a long time with the other
organs of the same name, but which differs from them in
a great number of characters ; I shall now speak of the
yellow or elastic texture. It will be necessary then
henceforth to divide the fibrous system into two great
classes ; one will compreheud the white fibrous organs or
albugineous one of M. Chaussier, the other the yellow
or elastic ones. The last expression is perhaps better.
adapted than the first to designate this kind of texture, as
its elasticity is its principal character, whilst the colour

172 ADDITIONS TO THE

/

is not as essential to it. Besides, no one that I know of,
has given a complete description of this texture ; it has
hitherto only been noticed in unpublished lectures. M.
Chevreul, it is said, is engaged in examining its compo-
sition. 7

This texture is met with wherever a resistance is re-
quired to be continually in action, a sort of perpetual
antagonism, differing in this respect from the ordinary
fibrous texture, whose resistance is, as it were, passive,
and which is only brought into exercise by distension,
and from the muscular, which only resists as long as its
contraction continues. It is found in animals under the
same circumstances. The posterior cervical ligament of
quadrupeds acts so as to oppose the weight, which inces-
santly tends to bend the head. A covering of the same
nature strengthens the abdominal parietes in the same
animals, and prevents them from yielding to the weight
of the viscera. The whole genus fe/is has an elastic
ligament inserted in the claw, keeping it extended, when
the animal no longer contracts its muscles to render it
prominent. The shells of the bivalves, oysters, muscles,
&c. are opened by means of an analogous fibrous texture,
when the muscles which shut them are relaxed. In man,
besides the yellow ligaments of the vertebrae, we should
also enumerate among the organs which this texture con-
tributes to form, the peculiar membrane of the arteries,
veins, lymphatic vessels, excretory ducts, air tubes, the
fibrous covering of the corpus cavernosum, the urethra,
and perhaps also that of the spleen. All these parts
require an incessantly active force, opposed to distension,
which makes them contract as soon as the contrary effort
ceases to have the ascendancy.

The fibres of the elastic texture have the same arrange-
ment as those of the white fibrous texture. Their colour

FIBROUS SYSTEM. 173

borders more or less upon yellow; it is more evident
in the dead body. Their tenacity is less than that of
the other texture; their elasticity, on the contrary, is
greater. The vessels of this texture are few.

Stewing does not resolve it into gelatine, like the white
fibrous texture. It appears to contain much fibrin, joined
to a little gelatine and albumen.

Its properties are slightly marked, except elasticity
and resistance, which especially characterize it. It does:
not appear to be sensible, or at least it is not so, like the
fibrous system in general, except to certain kinds of im-
pressions. It is rarely ossified. Its functions are to
serve as a connexion or covering, and to perform at the
same time the office of a spring, which obeys extension
and contracts quickly when the extension ceases. This
is what is very evident in the arteries; the column of
blood which they contain, moved at each contraction of
the ventricles, stretches the parietes of these canals; but
the instant after, elasticity contracts these parietes ; hence
the course of the blood is continuous, whereas it would
be interrupted if the heart was the only agent of impulse,
as we have said elsewhere.

|

MORBID ANATOMY OF THE FIBROUS SYSTEM.
I. Alterations in the External Forms.
The ligaments and tendons become thick and soft. in

white swellings; they are then brittle, if we may so
say, and yield to the least efforts made upon them. The

174 ADDITIONS TO THE

surrounding cellular texture is often confounded with
them and with that of the neighbouring parts, which
takes from them their mobility, and explains in part the
immobility of their situation and the embarrassment of
the motions which almost always accompanies these dis-
eases. In other cases, as in some contractions, the mo-
tions are prevented by the rigidity which the tendons
acquire, and by the difficulty with which they are stretch-
ed. The ligaments have a similar rigidity in false an-
chy losis. KEE

IL. Alterations in the Organization.

Inflammation of the fibrous parts is but little known.
That of the periosteum is the most common ; it performs
avery great part in many of the diseases of the bones.
I have seen several tendons the seat of slow engorgement,
which had sometimes been evidently the consequence of
an acute inflammation, such as that produced by a punc-
ture, for example. I have myself had an affection of
this kind which .was produced by a puncture on the
hand ; a tumour formed in the extensor tendon of a
finger and continued a very long time.

It is particularly in ruptures of the tendo Achillis that
we have occasion to observe the mode of reunion of
the fibrous organs when divided. <A coagulable matter
of the nature of albumen or fibrin is then poured out,
which gradually increases in density, till it finally
unites with solidity the two ends; this substance, soft
and extensible in the beginning, is capable of being elon-
gated at this period, as happens in fact when the limb is
too much moved. The rupture of the ligaments almost
always. takes place in luxations; but what takes place
after the reduction of these last has not been described.

FIBROUS SYSTEM. 175

' Ossification is rare in the fibrous texture. The kind
of hardening which this texture undergoes in old age
hardly ever extends so as to produce this transformation ;
it scarcely ever takes place except in the tendons, at the
places where there is friction, and in the ligaments, at
their extremity attached to the bones. It is not the same
in some animals; in the gallinaceous ones, for example,
the tendons of the muscles of the feet are uniformly
osseous at a certain period.

The periosteum is sometimes affected with cancer, as
is seen in what some call the fungus or medullary
Sungus of the periosteum, others the bony tumour,
lymphatic tumour of the periosteum, &c. Other
fibrous organs, as the dura mater, exhibit analogous tu-
mours. Periostosis differs from these tumours in this,
that it is the effect of an exudation which takes place
below the periosteum detached from the bone; the matter
of this exudation becomes sometimes more and more
consistent ; we have seen that it may become osseous.

Ill. Alterations in the Development.

Certain defects of conformation are accompanied with
an extreme relaxation of the ligaments which unite the
bones, of which club-feet furnish an example; the relaxa-
tion in this case is but a secondary circumstance, which
is owing to the weakness of some of the muscles.

The fibrous texture is produced under many circum-
stances, Ist. Without speaking of its reproduction
when it is divided itself, the cicatrices of various organs
are essentially fibrous ; this is what we have already
seen under some circumstances in the bones, and what
we shall see hereafter in the muscles and the skin. 2d.
The cellular texture, the retina, the substance of the tes-

176 - ADDITIONS TO THE

ticle and the thyroid gland are sometimes changed into
the fibrous texture. 3d. Various fibrous productions are
developed in the substance of the organs. They assume
the form of membranes, as in cysts, fasciculi, as in the
ligaments of the false articulations, or they are masses
known by. the name of fibrous bodies. These bodies
are especially met with in the uterus; Bichat mentions
them. They occupy different points of the substance of
this organ. Their number varies; many are often found.
At first very small, they gradually increase in size, and
become in some cases considerably large. Their fibres
form layers nearly concentric, and appear as if wound
like balls; they receive vessels more. or less apparent.
These bodies often pass to the fibro-cartilaginous state;
but this state is not peculiar to them, as has been said.
Ossification even may seize upon them ; they then resem-
ble stones or concretions. Sometimes they are entirely
detached and fall off, either into the cavity of the perios-
teum, or into that of the uterus; they form, in the
second case, the pretended calculi of the womb, of which
many examples are found in a memoir by Louis inserted
among those of the Academy of Surgery. The fibrous
bodies of the uterus have been known for a very long
time ; Chambon gave them the name of scleroma. But
it is especially to Bichat, whose ideas upon this subject
haye been published by M. Roux, and to Bayle, that
we are indebted for a more accurate description. Analo-
gous fibrous bodies have been found in other parts, as in
the neck and in the substance of the fingers. It is not
unusual to find around the vagina, between the bladder
and this canal, between the latter and the rectum, or in
its parietes even fibrous tumours, which, in truth, differ
a little from the preceding. They have not the knotty
appearance of these last; their texture, soft and flexible,

FIBROUS SYSTEM. ~- 177

has some resemblance to that of ordinary polypi. But
they do not arise like them; their adhesion to the neigh-
bouring textures is slight, so that their extirpation is not
difficult. M. Pelletan cites examples of this affection ;
M. Dubois has observed ita great number of times; I
have myself seen many of these tumours. Their structure
deserves to be examined thoroughly. It is important to
know them in pra¢tice, because if care be not taken, mis-
takes on this subject may be committed.

23

"ADDITIONS

FIBRO-CARTILAGINOUS SYSTEM.

e
—_—_—_—

Of the Nature of the Membranous Fibro-Cartilages.

Page 316.—< It is not only in its form, but also in
its nature, that this class’? (viz. that of the membranous
fibro-cartilages) ** differs from the others as we shall see.”’

This nature is perfectly analogous to that of the carti-
lages, which the membranous fibro-cartilages resemble in
all their characters, as may be easily seen by comparing,
in the history of the fibro-cartilaginous system, their pro-
perties with those of the other bodies which are classed
under it. Thus Meckel in his General Anatomy, observ-
ing entirely the distinction established by Bichat, between
this system and the cartilaginous, places these organs in
the latter under the name of membranous cartilages.

180 ADDITIONS TO THE

I am entirely of his opinion. In fact, 1st, like the carti-
lages, and the pretended membranous fibro-cartilages they
seem to be homogeneous in their structure, and have no
evident fibres. ‘Those which cover this surface belong to
the perichondrium, which is very thick upon these carti-
lages; when stripped of this membrane, they have the
appearance of the cartilaginous texture. . 2d. Gelatine
cannot be extracted from them by ebullition, as from the
- other fibro-cartilages. They are on the contrary in this
respect like most of the cartilaginous textures. Desicca-
tion also acts upon them nearly as upon these last. 3d.
Most of the fibro-cartilages are destitute of perichon-
drium; these have it very distinct, as 1 have just said.
It is to the fibrous texture which covers them that these
cartilages owe their suppleness, the only property which
they have in common with the fibro-cartilages.

Of the forms of the Fibro-Cartilaginous System.

Page 316.—‘‘ These three classes of fibro-cartilages,”’
(the membranous, articular and those of the tendinous
sheaths,) ‘‘ though very analogous, have not exactly the
same structure, the same vital properties, nor the same
life, &e.”?

If the first class be rejected, in conformity with what
has been said above, there will remain the articular’ fibro-
cartilages and those of the sheaths of the tendons, which
are in fact very different from each other. These differ-
ences appear to have their source principally in the differ-
ent proportions in which the fibrous and cartilaginous
textures are in this system; whence results a more or
less perfect resemblance to one or the other of these tex-

FIBRO-CARTILAGINOUS SYSTEM.

181

tures, a more or less evident fibrous structure, resistance
and flexibility, or, on the contrary, more or less elasticity
and homogeneousness. The following table may be made
of the fibro-cartilaginous system, by adding to the forms
pointed out by Bichat, that of the rings of this nature in
which the superior extremity of the radius and the ten-
don of the great oblique muscle of the eye slide, and of
the bands, also fibro-cartilaginous, which increase the
depth of certain articular cavities.

FIBRO-CARTILAGES,

A

f ARTICULAR.
They are in re-
lation with the ar-
ticular surfaces of
the bones, and per-
form various uses
towards them.

arthrodial articula-
tions are embrac-
ed by the synovial
membrane of these
articulations.

They may be di-
vided into

OF SLIDING.

Their name in-
dicates their use ;
almost all are con- <
nected with the
tendons.

. They are

Those of the di-4 Adherent ;

These are
so

covering.

4

a

(Free ; example, that of the lower jaw.

By their extremities, as that
of the clavicle, of the inferior
extremity of the ulna, those of
| the knee, &c.

By one of their surfaces, as
the bands which are attached
to the edge of the glenoid, and
cotyloid cavities.

By their two surfaces ; such
are the inter-vertebral sub-
stances, those of the pubis, sac-
Lrum, &c.

Flat; those of the 4 saben sheaths or of

Circular ; the pulley of the great oblique
muscle of the eye, and the annular ligament ,
of the radius; this serves besides to close the
| articulation of this bone.

182 ADDITIONS TO THE

MORBID ANATOMY OF THE FIBRO-CARTILAGINOUS SYSTEM.
T. Alterations in the External Forms.

The inter-vertebral substances are sometimes found in
diseases remarkably swollen, softened and engorged with
fluids; which produces a greater mobility and less solidi-
ty in the vertebral column. The symphysis pubis still
more evidently undergoes this alteration in pregnancy.

Il. Alterations in the Organization.

The organic affections of the fibro-cartilages are but
little known. Yet ulcerations have been seen in them;
Messrs. Palletta and Brodie have described a variety of
vertebral diseases which commence by the erosion of
the inter-vertebral fibro-cartilages.

The manner in which these organs are repaired when
they are divided, has not been ascertained. It might be
easily seen, for example, after the operation of the divi-
sion of the symphysis pubis.

As to the ossification of the fibro-cartilages, a distinc-
tion may be established here, as in the cartilaginous sys-
tem, founded upon the period at which this ossification
takes place. There are in fact, temporary fibro-carti-
lages which serve as moulds for the bones, as there are
eartilages of this name; these are regularly ossified, and
this transformation is for them only a consequence of their
natural development. These fibro-cartilages of ossifica-

tion are met with where bones are developed in the
fibrous textures, as is seen in the article on the osseous

FIBRO-CARTILAGINOUS SYSTEM. 183

system, with regard to the sesamoid bones; the osseous
points of the stylo-hyoidean and thyro-hyoidean liga-
ments are also formed in this manner. On the contrary,
the permanent fibro-cartilages rarely pass into the osseous
state. This sometimes happens as has been said, with
regard to those of the vertebrae; yet oftentimes in these
cases, the external layers alone are invaded. At the
pubis, this phenomenon is extremely rare ; it is a little
less so in the sacro-iliac symphysis and in the sacral ar-
ticulations. The fibro-cartilaginous organs seem to be, in
this respect, intermediate to the cartilaginous and fibrous
textures, as they are so in many others, they are ossified
less often than the first, but more frequently than the
second.

fll. Alterations in the Development.

There are preternatural fibro-cartilages, 1st, in the cure
of some fractures badly kept in place; 2d, in false ar-
ticulations, in consequence of which the periosteum often
takes this form; 3d, in alse anchyloses, which are some-
times produced by filaments of the same nature; 4th,
finally, in cysts, in tumours of the uterus, the thyroid
gland, &c. and in which are often found some fibrous,
fibro-cartilaginous parts, &c. |

ADDITIONS
ee

TO THE

MUSCULAR SYSTEM OF ANIMAL LIFE.

Intimate Structure of the Muscles.

Page 335.—‘‘ I would compare the anatomical re-
searches upon the intimate structure of the organs, to the
physiological researches upon the first causes of the func-
tions. In both we are without guides, without precise
and accurate data; why then give ourselves up to them ?”’

Notwithstanding the little apparent utility which .these
researches seem to have, since many learned men are oa
engaged in them, I thought it might be satisfactory to fin
here ashort analysis of the labours and opinions of which
the muscular fibre has been the object. 3

Some consider it divisible almost ad infinitam; Muys
says that each fasciculus must be divided and subdivided
eight times before we can arrive at the ultimate muscular

24

186 ADDITIONS TO THE

fibre ; others, Prochaska for example, think that these
divisions are much too numerous. There is the same
difference of opinion as to the size of this fibre. It is
less, according to most authors, than the globules of the
blood. Sprengel, who has measured it by the micrometer
of Banks, attributes to it, on the contrary, a much greater
diameter, which he considers to be equal to the fortieth
of a line in the mammalia, and to the twentieth in birds
and fishes.

The muscular fibre appears to be unequal and as it
were wrinkled on its surface, which has been variously
explained. It has been said that these inequalities were
the mere effect of muscular contraction ; that they were
owing to the contractility of texture of the cellular and
vascular parts which surround the fibre; that it is a con-
sequence of the knots and contractions, of which this is
composed. This last opinion is best founded in insects,
which exhibit evidently in their fibres this kind of
knotty appearance; but it is not by any means, so evi-
dent in man. Meckel, who has seen this arrangement
very clearly in the first by the microscope, has not been
able to detect it in the second. The muscular fibre has
appeared to him in man, to be nearly uniform and of the
same size in all its points; only there is always observed
in it globules or opake points, separated by a more trans-
parent medium; which is very different from the knots
Home has also observed globules in the muscular fibre.
By examining this fibre, deprived of its cellular texture
by ebullition, as it should always be when we would
study it by itself, and by maceration, he has seen it re-
duced to round particles precisely similar to the globules
of the blood. |

Various observers have examined with the microscope
the transverse section of a muscle. The surface of this

MUSCULAR SYSTEM OF ANIMAL LIFE. 187

section resembles very much that of basaltic earth’ the
fibres are compact, flattened, and prismatic rather than
cylindrical. A very good idea of them may be formed
from a plate which Prochaska has given.

Is the muscular fibre solid or hollow? This is a ques-
tion with which anatomists have been much engaged,
though it is hardly; possible to answer it by inspection.
Thus there has been scarcely any thing but suppositions.
formed on this subject. However, Lecat, Verheyen and
Vieussens are all agreed upon this point, and have be-
lieved that it might be concluded from their observations
that each fibre of a muscle was an assemblage of vessels
of a particular order, continuous with the arteries and the
veins at the place where these two orders of vessels are
confounded, but placed out of the circulation of the latter.
These vessels, which might be called vessels of deriva-
tion, are admitted by Maseagni; they are the same that
Bleuland says he has found in the capillary system in
general, and in other parts as well as the muscles. Hal-
ler, on the other hand, rejects this opinion. All those,
who like him, divide the parts into those that are capable
of being injected and those that are not, and this is the
ease with the greatest number of anatomists, think that
the muscular fibre is solid and beyond the circulation of
the fluids. |

Influence of the Nerves upon Muscular Irritability.

Page 384.—‘‘ The duration of this last property,’ (sen-
sible organic contractility,) * after the experiment I men-
tioned,”’ (the division of the nerves,) “¢ proves completely
that the nerves are wholly foreign to it, that it resides
essentially in the muscular texture, that it is, as Hal-
ler said, inherent in it. Thus whilst in the different

188 ADDITIONS TO THE

paralyses the muscles lose the power of obeying the
cerebral influence, or rather this influence becomes nothing,
they preserve that of contracting in an evident manner
when stimulated.”

When all the nerves of a muscle are cut, the muscle
preserves only for a time the faculty of obeying the action
of stimuli; the contractility is soon exhausted and does
not reappear. On the contrary, when the communica-
tion with the nervous centres is free, the irritability
diminishes also in proportion as it is put in exercise, and
finally, as in the preceding case, disappears entirely ;
but if the animal is suffered to rest, it is reproduced.
Hence it would seem, that this property is not inherent
in the muscle, but that it is entirely subjected to the ner-
vous influence. The duration, besides being shorter, of
the irritability after the division of the nerves may very
well depend upon the influence of these nerves below the
division; an influence which can ‘continue but a little
time, not being renewed, from the want of communica-
tion with the nervous centres. According to this idea,
which is that of Platner, Legallois, &e. the muscles
only put in action a principle which is brought to them
by the nerves, and these perform a double part in the
contractility of the muscular texture; Ist, they keep
this texture in a state of constant excitability for the sen-
sible organic contractility ; 2d, they transmit the excite-
ment under certain circumstances, as it respects the will,
for the animal contractility. The muscles are to the
nervous system what the senses are to this system, parts
whose action is intimately connected with its own, and
becomes nothing without it. And in fact this action, in
the first as in the second, is exhausted, lost and repro-
duced nearly in the same manner. Sleep, rest and food

MUSCULAR SYSTEM OF ANIMAL LIFE. 189

reestablish the muscular energy when weakened by long
exercise, as they restore energy to the senses when theirs
has been destroyed by the same cause. We have just
seen that this does not appear to apply solely to animal
contractility, but also to sensible organic contractility,
or irritability properly so called.

However, all physiologists are far from being agreed
in the above opinion. A great number have followed
the opinion of Haller, and attributed to the nerves, no
other use in contractility, than that of conducting the
stimulus when it comes from the brain. They rely upon
this, Ist, that Tourdes has ascertained that there is mo-
tion in pure fibrin; 2d, that vegetables and zoophytes
contract, though they are evidently destitute of nerves ;
and 3d, that contractility is put into action in the muscles
by stimuli which are directly applied to them. But, Ist,
in admitting the experiment of Tourdes, which no one
since has confirmed, its results are very different from
those of muscular contractility ; 2d, vegetables and ani-
mals without nerves are also without muscles, thus their
contraction has nothing in common with the latter ; 3d,
the last argument is in part combatted by all the reasons
alleged aboye in favour of the opposite opinion. It is
very difficult, however, to resolve the question in an
absolute manner. We find in Meckel a sort of mixed
opinion, which is perhaps the most accurate. According
to this author, the nervous influence is one of the condi-
tions necessary to contraction, but it only operates like
the blood which the arteries bring, being like it indispen-
sable to the life of the muscle, which does notwithstand-
ing possess its irritability of itself.

190 ADDITIONS TO THE

Quickness af the Muscular Contractions.

Page 395.—** When it is the will that regulates the
quickness of the muscular-contractions, this quickness
has infinitely various degrees; but there is always one
beyond which we cannot go.’’

This quickness is in general very great; it becomes
sensible especially in the action of playing upon different
instruments ; it is found by estimating how many differ- |
ent movements each note of music requires that there is,
in general, a contraction every sixtieth of a second. Dr.
Wollaston has obtained the same result in another man-
ner. His researches are given in a Croonian Lecture pub-
lished in the Philosophical Transactions for the year
1810. The following is the means he adopted to mea-
sure the quickness of the contractions.

According to his researches, muscular contraction, how-
ever short may be its duration, is, as it were, intermit-
tent, and composed of many alternate small contractions
and relaxations; the kind of buzzing which is heard in
the ear when its aperture is closed by the extremity of
the finger, is a proof of it. This peculiar noise is owing,
according to Dr, Wollaston, to the muscular effort which
the attitude requires; and in fact I have proved that it is
nothing when the finger is replaced by an inanimate body.
Now, this buzzing includes a series of oscillations very
near together which correspond to so many contractions
of the muscles; it was only necessary then to find a term
of comparison for these oscillations, this Dr. Wollaston
has done. He has compared this noise to that which the
motion of a carriage produces, which is also intermittent,

MUSCULAR SYSTEM OF ANIMAL LIFE. 191

and the frequency of which it is easy to estimate. He
has ascertained the quickness stated above.

Size of the Muscles in Contraction.

Page 398.—‘‘ Their volume”? (that of the muscles
which contract) “remains about the same. What they
lose inlength they nearly gain in thickness. Is the pro-
portion very exact? Of what consequence to us is this
insulated question, to which, since the days of Glisson,
so much importance has been attached ! it deserves none.”’

There are moreover many causes of error in the ex-—
periments which have been made on this subject. Swam-
merdam, for example, says that by placing the heart of a
frog in water the fluid is seen to sink at the moment of
contraction and to rise in the relaxation ; but the heart
containing a fluid which can increase or diminish the size
of it, without any change in the texture of it, it is evi+
dent that nothing can be concluded from this experiment.
So in that of Glisson, who immersed the arm of a man in
a tub, and afterwards observed the difference of the level
according to the state of contraction or relaxation of the
muscles, the results cannot inspire great confidence, be-
cause on the one hand, it is quite difficult in this case to
ascertain precisely the level, and because on the other,
the contraction of the muscles being always accompanied
by the relaxation of the opposite muscles, it is impossible
to distinguish these two effects from each other.

One fact which seems to offer something more positive,
was ascertained by Erman. This physiologist, having
put a piece of an eel in a narrow tube of glass containing
water, saw at each contraction which a stream of gal-
vanism produced, the water evidently sifk, and rise again
during the relaxation.

192 ADDITIONS TO THE

Besides, this question, with which authors have been
much engaged, has been resolved by them in all ways.
Some have maintained that the muscle was diminished,
others have pretended that it was increased, and finally
others have been certain, that it was neither increased
nor diminished; it would be difficult to imagine a fourth
opinion. | |

State of the Circulation in the Muscles during
Contraction.

Page 398.—*‘ The blood contained in the vessels of the
muscles, especially in the veins, is in part pressed out; the
increase of the flow of blood by the motions of the arm
in the operation of bleeding proves this fact.’?

This fact is differently explained by many physiolo-

gists, who admit that the circulation becomes more rapid
in a muscle that is in a state of contraction, and attribute
to this circumstance the increase of the jet of blood by.
the motions in the operation of bleeding. But the greater
activity of the circulation during the muscular contrac-
tion is far from being rigorously demonstrated. Let us
_see in fact upon what this assertion rests,
Ist. It is evident that the fact of the bleeding cannot
establish this opinion, since we have just seen that it is
easy to account for it without being obliged to have
recourse to .it; in fact, the muscles being increased in
thickness in their contraction must necessarily compress
the deep-seated veins, by the resistance of the aponeu-
roses of covering, which then perform the office of a liga-
ture in relation to these veins; hence it is not surprising
that the blood goes in greater quantity into the sub-cuta-
meous veins.

MUSCULAR SYSTEM OF ANIMAL LIFE. 193

2d. The panting, which always follows great motions,
has been cited ; it is, it is said, because the circulation of
the blood through the muscles is more rapid, and the
lungs consequently receive it in greater abundance, that
respiration is accelerated in this case; thus the muscles
which serve for this function are then in extreme activ-
ity, and sometimes finally become so fatigued that respi-
ration can be no lénger supported by them, as is seen in
animals pursued in the chase, who at last fall down.
But it is necessary to take into account here a principal
cireumstance, omitted in the explanation that has been
given of this phenomenon ; it is, that the parietes of the
thorax, contracted and immoveable, are to serve as a
fixed point for the action of all the muscles of the body,
in all violent and extensive motions. Now this circum-
stance explains all the others; the circulation is more
rapid, because the vessels being compressed in the chest,
less blood can go through them in a given time ; respi-
ration is panting, because the permanent contraction of its
muscles impedes inspiration, and it is necessary that its
frequency should compensate for its want of extent ;
finally the muscles of inspiration are fatigued by the ier
with which they are compelled to resist all the other
muscles of the body. The more rapid passage of the
blood in the muscles is not then, in this case, an immedi-
ate consequence of their contraction, but is owing on the
contrary to a cause, which to a certain extent is foreign
to it.

From these different considerations, it is evident, that
nothing proves that the circulation of the blood is more
active in a muscle at the time of its contraction, as has
however been almost generally thought. The various
hypotheses, by means of which it has been pretended
that the muscular action could be explained, haye no

25

194 ADDITIONS TO THE

doubt given rise to this idea, which could never have
arisen from observation, and of which it has been thought
that proofs were afterwards found, when the imagination
had once created it. It is thus, that Prochaska could
hardly refuse to admit it, when he supposed, very ingeni-
ously it is true, that the shortening of the muscles. in
their contraction depended solely upon this, that the ves-
sels placed transversely in the substance of their fibres,.
suddenly distended by the fluids which entered them,
separated these fibres and made them suddenly fold up.

State of the Muscles after Death.

Page 419.—* It appears that these different states’’ (of
rigidity or relaxation) ‘* depend upon the kind of death,
upon the phenomena that accompany the last moments.
But how do they precisely happen? It is an object of
interesting research.”

The Physiological Researches of Nysten and one of
the synoptical tables of Chaussier may be consulted with
advantage upon this point. Muscular rigidity is constant
after death ; it is a consequence of irritability ; the muscles.
are in a state of real contraction. This phenomenon
appears also to be connected with the eoagulation of the
blood; for all the causes which retard or promote the one
have the same action upon the other; a warm bath, by pre-
serving the heat in a dead body, and by preventing the
coagulation of the fluids, keeps up also the suppleness of
the muscles. But what proves that cold is not the sole
cause of the rigidity, is that this disappears after some
time, and that the muscles are relaxed of themselves
before the period of putrefaction. The kind of death has
an influence upon the duration of the contraction and the

MUSCULAR SYSTEM OF ANIMAL LIFE. 195

time in which it comes on. In diseases with exhaustion,
such as scurvy and. gangrenous diseases, the rigidity
appears very soon after death, but soon gives way. On
the contrary, after acute diseases and sudden deaths, it
does not come on for one or two days, but continues a
much longer time; it is also greater in the last case.
Besides, the muscles are not the only seat of this rigidity,
the cellular texture and the fibrous parts partake of it also.
The muscles of organic life experience it, like the exter-
nal muscles, although it is in the latter that it is particu-
larly observed.

Morbid Anatomy of the Muscular System of Animal
Life. .

The alterations which the muscles of animal life under-
go will be described with those ef the muscles of organie
life.

7

ADDITIONS

To THE

MUSCULAR SYSTEM OF ORGANIC LIFE.

Influence of the Nervous System upon the Muscles of
Organic Life.

Page 24, vol. 3d.—‘* The cerebral and nervous influ-
ence upon the organic muscles is not known to us.—It
is however real to a certain extent, since it is necessary
that the nerves which enter into the composition of these
muscles should be of some use; but we are ignorant of
this use.”

We have seen in the muscular system of animal life,
that the influence of the nerves upon the irritability of
this system cannot be easily determined. The same
question recurs here, and is even more complicated. In

198 ADDITIONS TO THE

fact, in the other system, there was at least an evident
action on the part of the brain and nerves in animal con-
tractility ; in this, this action not only becomes doubtful,
but the same difficulty exists, and even a greater one per-
haps, in relation to the part which the nerves perform in
the organic contractility. It may be asked, Ist, if the
brain has any influence upon the contractility of the
muscles of organic life ; 2d, if the spinal marrow be not
necessary to the exercise of this contractility ; 3d, if the
nerves be purely passive in this phenomenon, so that this
property is, according to the expression of Haller, inhe-
rent in the fibre of these muscles.

The considerations offered by Bichat show that the
muscles of organic life are independent, in their action, of
cerebral influence ; but they do not prove that this cannot
be exerted under some circumstances. Many of the facts
which he has brought forward tend, on the contrary, to
demonstrate this influence. The passions are a remarka-
ble example of it. It appears to me to be extremely pro-
bable that, when in.a strong emotion, for example, the
motions of the heart:are accelerated, it takes place only
because the brain reacts upon this organ and transmits to
it the impression which it has received. Placing the
primitive seat of the passions in the organs .of internal
life, is forgetting, it seems to me, that the brain is the sole
organ of the perceptions, and that ‘the passions are always
the consequence of these last. ‘This however is not the
place to discuss this question ; it is sufficient to show that
the action of the heart may in this case be entirely sub-
jected to that of the brain. Those cases, rare ones indeed,
in which the will ean suspend the action of the first of
these organs, seem to belong to the same cause. Bayle,
who possessed this singular faculty, could put it in exer-
cise instantaneously and with the same ease that he could

MUSCULAR SYSTEM OF ORGANIC LIFE. 199

move a muscle of animal life; now, if this depended on
the suspension of respiration, it would require some time
for the phenomenon to take place. Moreover, the heart
is not the only organ which thus obeys, in some cases, the
influence of the brain. Many facts show that the stomach,
intestines, bladder and even the womb are also sensible
to this influence; we know not, it is true, if it be by the
nerves that it is transmitted; but as these agents are the
only means of communication of the brain with these:
different organs, every thing leads to the belief that such
is their use. It must however be acknowledged that we
want direct experiments in order to place this beyond
doubt. On the contrary, those that have been hitherto
made teach us, that the brain can be removed without
diminishing at all the action of the muscles of organic life,
if care be taken at the same time to support respiration.
What can we conclude from these opposite facts and from
those stated by Bichat? that no doubt the cerebral influ-
ence is not absolutely necessary to the contraction of these
muscles, but that it can modify it under certain circum-
stances. We shall now see that it is nearly the same
with regard to the spinal marrow.

On the one hand, Legallois, by numerous experiments
which have already been noticed in the article upon the
nervous system of organic life, has pretended to prove
that the heart receives, by the great sympathetic, from
every part of the spinal marrow, the principle of its
motion, which is annihilated when this is wholly de-
stroyed ; on the other hand, various facts, which have been
stated in this same article, from the experiments of Clift
and Wilson Philip, demonstrate that often, notwithstand-
ing the absence of the spinal marrow, the heart continues
its action ; that some lesions of the spinal marrow have
more influence than others upon this organ ; that, accord-

200 ' ADDITIONS TO THE

ing to the age and the species of the animal, great differ-
ences in the results are observed, &c. Whence it is seen
that the organic contractility, though independent to a
certain extent of the spinal marrow, is in some case
influenced by it.

Finally, is the continuance of this contractility, not-_
withstanding the destruction of the brain or spinal mar-
row, a proof that the muscular fibre is of itself endowed
with it, independent of all nervous influence, as Haller
thought? Certainly not, since the nerves exist and can
still act insulatedly in this case. Nothing is opposed to
our admitting here the same hypothesis as in the muscular
system of animal life, viz. that the muscles derive from
the heryous system the principle of their action; but I
know of no fact which proves this in an incontestable
manner.

Duration of the Organic Contractility.

Page 38.—* This duration is longer than that of the
animal contractility. When the spinal marrow is irritated,
the external muscles remain immoyeable, whilst the inter-
nal ones are still in activity.”

This comparison has for its object only the two species
of contractility, considered in the two corresponding sys-
tems. But that of animal life enjoys not only the con-
tractility of this name, but possesses also, according to the
distinction made by Bichat, organic contractility. Now
this differs, as it respects its duration after death, in the
different muscles of the two systems.

Haller, who perceived this fact, says that it is the
heart which remains the longest sensible to the action of
stimuli; that next to it, the intestines are the slowest in

MUSCULAR SYSTEM OF ORGANIC LIFE, = 29)

losing the faculty of contracting; that the stomach comes
next and then the diaphragm, and that finally the exter-
nal muscles are the first in which this faculty is extin-
guished. He adds, that in some cases, the intestines ap-
peared to him to preserye their irritability longer than the
_heart.. New researches, far which we are indehted par-
ticularly to Nysten, prove that this order is not in fact
exact.. The kind ef death, the nature of the stimulus em-
ployed, &c. make the duration of the irritability vary in
the different muscles ; it is thus that the heart for a longer
time obeys the irritation which arises from a puncture with
the point of an instrument, whilst the voluntary muscles
are longer sensible to the stimulus of Galyanism.

A numerous series of experiments has enabled N ysten
to establish the following order, which is yery different
from that of Haller; Ist, the left ventricle of the heart,
which gives for the shortest time signs of irritability, and
is thus found at the bottom of the scale ; 2d, the large in,
testines ; 3d, the small intestines ; 4th, the stomach ; 5th,
the bladder; 6th, the right ventricle; 7th, the oesopha,
sus; 8th, the iris, whose motions this physiologist has
also examined ; 9th, the muscles of the trunk; 10th,
those of the Siftion extremities ; 11th, those of the supe-
rior extremities; 12th, finally, the auricles, the contrac-
tility of which is preserved after this property has ceased
in all the other parts; it is extinguished in the last place
in the left auricle, a fact very long known, and which is
mentioned by Galen. |

Force of the Dilatation of the Muscles.

Page 54,—* It appears then very probable that the
dilatation of the organise muscles is a phenomenon as vital
as their contraction,””

26

202 “ADDITIONS TO THE

Without absolutely denying that the internal or invol-
untary muscles can be dilated and the voluntary ones
elongated, by a peculiar vital action, analogous to the
contraction of these same muscles, I would observe that
most of the facts which tend to prove this action can be
explained in another way, and often depend on causes
which are wholly foreign to it, and which have been
overlooked by those who admit this action. It is thus
that Barthez cites as phenomena of this kind, owing to a
sort of active repulsion opposed to the attraction which
predominates in the shortening of the muscular fibres, the
elongation of the trunk of the elephant, that of reptiles,
worms, &c. in the act of crawling, and even that of the
tongue. It is evident that; in all these cases, the elonga-
tion is but a secondary effect of the shortening of certain
muscles, which by their arrangement, cannot produce it
except by a real dilatation. The leech, for example, has
longitudinal fibres, the effect of which is to shorten it, but
‘as it has at the same time circular fibres which cannot be
contracted without elongating it, the space which ‘these
fibres enclose evidently increasing in one direction,
whilst it diminishes in another. It is the same with re-
gard to worms, &c. The trunk of the elephant also con-
‘tains two sets of fibres, the longitudinal ones to shorten it,
and the radiated ones serve to elongate it, and it is not to
the dilatation of the first that this last effect must be at-
tributed.

It is for the want of having known the true arrange-
ment of the muscular fibres in certain parts, and not
having appreciated the different effects of the contraction
of these fibres according to the direction they take, that
some haye been led to give them a force of expansion
which by no means appears to be inherent in them.
What takes place in the intestine confirms this idea ;

MUSCULAR SYSTEM OF ORGANIC LIFE. 203

there is no doubt that the alternate extension and contrac-
tion which agitate this viscus depend on the alternate con-
traction of its longitudinal and circular fibres; yet this
fact is one of those which has been given in proof of the
active dilatation of the muscles. i

IF. Meckel has presented some new considerations in
support of the latter, drawn from the different states in
which the muscles’ are found after death, from the mo-
tions which are observed in the iris, from the variable
dimensions of the pupil in the dead body, &c.; but if we
except from them the iris, whose motions are, I think,
but little known, and whose muscular nature is moreover
far from being demonstrated, the contraction alone of the
muscles perfectly explains almost all the phenomena of
which they are the seat. A single one, already cited by
Bichat, seems at first favourable to the active elongation
of the fibres, inasmuch as it appears hitherto inexplicable ;
it is the force with which the heart rises up and tends to
dilate itself, even when the blood does not enter its inte-,
rior. But is this fact, though obscure, more conclusive,
and may it not be owing, like the others, to some partic-
ular cause which is unknown to us? Who can say that
the diastole and systole will not be one day as simple
phenomena, as those of the contraction of a voluntary
muscle ?

964 ADDITIONS TO THE

-

MORBID ANATOMY OF THE MUSCULAR SYSTEM:

The alterations common. to the two great divisions of
this system may bé united in one description. There
are a few particular ones, which will be noticed.

I. Alterations in the External Forms,

Excess of nutrition is common in the muscles; but it
is hardly any where but in the heart and the bladder that
it constitutes, properly speaking, a disease; it is charaé-
terized by a remarkable increase of size and often of den-
sity. Atrophy often takes place in the external muscles,
from the want of exercise, distension or some other cause.
There is frequently joined with it a discolouration of the
fleshy fibres, which has been taken for a fatty state, as
Bichat has already observed. The pretended fatty alter-
ation of the muscles does not appear to me to exist, at
least I know of no instance which cannot be referred to
the preceding state, in which, the fleshy fibres disappear-
ing in part, the intermuscular fat predominates and is con-
founded in its colour with the muscle itself, that has be-
tome yellowish. But we find by analysis fibrin in these
muscles; by putting some of it on brown paper, distinct
fibres aré discovered after the animal oil has been absorb-~
ed, &c. In the heart, atrophy occasions the dilatation of
this organ, its passive aneurism.

The muscles lose their consistency under many circum-
stances ; the heart is very subject to this alteration,
which has been described by M. Laennec in his excel-
tent work entitled T'raité de l’ Auseultation Mediate,
in which will be found a great number of interesting facts
upon the diseases of this viscus. The softening of the

MUSCULAR SYSTEM OF ORGANIC LIFE. 205

muscles may bring on hades rupture ; that of the heart
has been often observed in similar cases, especially in old
people; it has been the subject of a particular work of
M. Rostan.

The muscular fibres are sometimes elongated from the
effect of different diseases ; there results from it a more
or less evident weakness of their action. This forced
elongation of the ‘muscles often exists at the same time
with the shortening of the antagonists, which is then the
eause of it ; it is sufficient, in this case, to counterbalance
the latter in order to restore to the former their contractile
faculty ; it is in this way that we sometimes succeed in
remedying the permanent flexion of the fingers, by
straightening them te such an extent that the extensors
can contract again; the same thing applies to the cure
of club-feet, when it is possible to bring back the axis of
the limb to its primitive direction.

Shortening has not the same inconveniences; it may
extend very far without being. perceived by the contrac-
tility, as proved by a preparation in Hunter’s collection,
in which the humerus had experienced a considerable loss
of substance. It seems on the contrary that this short-
ening power was increased in it; at least it is then in
continual exercise. This sort of retraction is very fre-
quent, and is most often connected with a weakness of
the antagonists. Contractions from the scurvy, certain
morbid curvatures of the trunk, club-feet, that we have
just noticed, strabismus, and the retraction of the muscles
of the leg by a continual pain in this part, are examples
of it. The little finger is often thus retracted. |

Much has been said of the displacements of the mus-
cles, of luxations, and hernias of these organs. What
Poutean has written upon this subject may be adyantage-
ously examined.

206 _ ADDITIONS TO THE

J

. UL. @lterations in the Organization.

Inflammation of the muscular texture is still doubtful.
Purulent centres have been found in the different regions
of this system, but they may have their seat in the cellu-
lar texture interposed between its fibres.

A muscle cut transversely retracts powerfully, as has
been seen elsewhere. But the inferior part is often para-
lyzed by this division, because a nerve is left in the supe-
rior, at that part of it in which it usually penetrates the
muscle; the latter preserves on the contrary its irritability ;
the retraction, which is so evident in amputation, depends
in a great measure on this cause. It would be the reverse,
and the inferior alone would contract if the division had
been made higher up. In all cases, to these phenomena
succeed those of reunion. A new fibrous texture fills
the space between the two ends, which it unites firmly
together ; if it. be short, it does not injure the contrac-
tion, otherwise the muscle would gain, as has been said ;
if the intermediate substance be long and extensible, the
motions are more or less injured. 7

Transformations are hardly ever seen in the muscles.
I have however found in them fibrous and osseous tu-
mours, which had a knotty appearance, analogous to that
of the tumours of this kind which are found in the womb.
We have seen above what should be thought of the fatty
transformation.

Morbid alterations (dégénérations) are also very rare
in this system. Hydatids may sometimes be produced in
it; they are common in hogs.

{ j
MUSCULAR SYSTEM OF ORGANIC LIFE. 207

Ill. Alterations in the Development.

The muscles of animal life have been wholly wanting-
in a foetus; there was under the skin, only a fatty mass,
formed of infiltrated cellular texture more or less consis
tent ; at other times, a part of these muscles is wanting.
The heart, in very rare cases it is true, has also exhibited
this anomaly, very frequent in some muscles taken sepa-
rately. Nothing is more variable, besides, than the ar-
rangement of the muscular system, considered in relation
to its external forms. We often find supernumerary mus-
cles, or those which should exist are removed, by their
conformation, from the natural order. The attachments,
direction, size and structure exhibit an infinite number of
varieties, all of which are in the province of descriptive
anatomy. The musclés of organic life are not exempt
from these varieties; the heart alone exhibits a great
“ number of them. am)

Some authors have spoken of muscular transformations ;
but the examples they have adduced are too vague to be
characterized. There seems to be a preternatural de-

‘velopment of the muscular texture in the womb, during
pregnancy, and in the round ligaments, at the same
period.

em
Mics

MUCOUS SYSTEM. =, re

not allow that these elongations contain vessels, at least
apparent ones. A viscid matter, a kind of jelly, a sub-
stance without form or organization, constitutes, accord-
ing to these authors, the villi, which have exhibited to
them with a microscope only this substance, and moreover
opake globules situated below it. This matter is capable
of being soaked and then becomes spongy ; this soaking
ean take place from within, that is to say, on the side of
the vessels, as well as from without, or on the surface of
the mucous membrane. The lymphatic vessels may arise
from this substance, which Alb. Meckel compares to that
which constitutes very young vegetables at the period of
their development. This description, if it be accurate,
would agree very well with the facts previously observed,
and would enable us to explain how Lieberkuhn saw a
vesicle, how Hewson found vessels, &c. There is, accord-
ing to Alb. Meckel, a circumstance which may account
for the various forms that have been attributed to the
villi; it is that the leaflets they represent are variously
folded, and twisted, and thus assume a variable aspect,
which depends on their situation at the moment they are
ebserved. It is owing to this that Hedwig calls them
eylindrieal, digitiform, terminated by an obtuse summit ;
that others have compared them to small clubs, &c.
Many anatomists are confident that there are apertures
on the summit of the villi, and that they are the orifices
of the lymphatic vessels. They are not however agreed
as to the number of these orifices. Bleuland and Hedwig
allow but one; Cruikshank and Soemmering have seen
from six to ten. Hewson pretends that these apertures
do not become distinct until the villi are rendered more
prominent, as happens from injection ; he supposes that
it is the same during life, and thus explains absorption by
the erection of which he believes these elongations sus-

212 ADDITIONS TO THE

ceptible. Those, who admit the opinion that was last
stated, reject all kinds of openings similar to absorbent
orifices; the soft matter, which has been noticed above,
is in the place of them, according to this hypothesis.

It is generally thought that the villi receive nerves ;
but this is rather from a presumed analogy with the
papilla and on account of the sensibility of which they
are the seat, than the result of inspection. M. Ribes
has injected veins in them from the vena porta; we
have seen that these elongations can be injected from the
arteries ; their lymphatic vessels are also evident; in
order to see them, it is only necessary to immerse the
membrane in alkohol; the fluids which they contain are
coagulated and render them more apparent.

| Mucous Glands.

Page 88.—‘‘ I cannot say whether nerves penetrate
them ; analogy indicates it, for all the principal glands
receive them.”

These small sacs are now distinguished from the glands,
and described under the name of follicles, which agrees
much better with their nature. They appear in fact to
be formed by a sort of inversion of the membrane in
which they are seated, and which being folded, at the
place where they are, beneath its free surface, constitutes
in this a real cud-de-sac, terminated by an orifice open
upon this surface. This arrangement is very evident in
the sebaceous follicles on the skin, with which ‘the
mucous ones have so great an analogy. ‘These last ex-
hibit it also evidently at their origin; there, as in all
the points where their epidermis is distinct, we can rais@,
this up entire with the elongations which it forms in the

‘ —
> Se P| ; a me)
TAM Ben & Cis LA MEE PF f Ty a a f <
hi \ eb hue Z uy a see

4

- ADDITIONS
TO THE

MUCOUS SYSTEM.

Villi of the Mucous Membranes.

Page 85.—* The delicacy of these elongations conceals
their structure, even from our microscopical instruments,
agents from which anatomy and physiology do not appear
to me to have derived much assistance, because when we
see obscurely, each sees in his own way and according to
his own wishes.”

A great number of observers, both ancient and modern,
agree in many points in relation to the arrangement of
these villi; they differ, it is true, upon others, but it is
easy to see that oftentimes the foundation of their obser-
vation is the same, and that the whole difference consists
im the manner in which they have given’ an account of

27

216 ADDITIONS TO THE

them. The intestinal villi have been the particular object
of their researches. The following is what is the least
obscure respecting the nature of these elongations.

The villi of the mucous membranes, examined with a
microscope, resemble the fibrous parts of the roots of cer-
tain trees. Yet their form appears to be rather flat than
round, and the name of leaflets (/folioles ) which has been
given to them latterly is perhaps better in this respect
than that of villi. Lieberkuhn had already noticed this
arrangement in man, but he admitted that those of ani-
mals were cylindrical, and consequently filamentous or
villous. They terminate ‘in a point, which, joined to
their flattened form, has led some to compare them, from
their appearance, to the leaves of the grasses. Rudolphi
says that they are lamine, small scales which furnish the
whole interior of the intestine ; this is not very far from
what we have just said. i

The structure of these elongations is the point that has
been the most contested. We know what was the vesicle
of Lieberkuhn ; this anatomist having observed that the
intestinal villi were swollen by injection, and that the air
driven in diffused itself in them and gave them a spongy
appearance, thought that he might conclude from it that
they. were in a great measure formed of a kind of cellular
vesicle, in which the vessels terminated, particularly the
lymphatics. Hewson has made observations similar to
those of Lieberkuhn, but he has not drawn the same con-
clusion from them ; according to him, the injection makes
the: villi stvell, and produces in them a phenomenon simi-
lar to that of erection; but this arises from: their- being
entirely, composed of a net-work of vessels, of a sort of
plexus similar to that which forms the erectile textures.
This opinion also is rejected by Rudolphi, Mess. Cuvier,
Alb. Meckel and many other modern anatomists, who de

MUCOUS SYSTEM. ° 215

of the mucous membrane being of small extent, which
forms them; they are, as it were, the rudiments of the
follicles. Their number is few at the bottom of the
oesophagus, where they begin to be perceived; between
the folds of this canal; it inereases in the stomach and
especially in the duodenum ; in this intestine and in the
stomach, the depressions have nearly the same breadth
as the interstices between them; they differ in this from
the alveole or bees’ cells which are in fact more nume-
rous, and whose interstices are much smaller. Their
parietes are smooth and rounded in the oesophagus and
in the neighbouring portion of the stomach’; they be-
come unequal as we examine towards the intestines, and
are furnished with small leaflets (foHoles) that are more
and more evident.
‘Sir Everard Home has examined with a microscope
the digestive surfaces of différent animals. It follows
from his observations, that, in animals who are nourished
by vegetable substances, the follicles of these surfaces
have a more complicated structure, are provided with
numerous villi at their orifices, and secrete a more active
juice; that animals, on the contrary, whose nourishment
is derived from ‘the animal kingdom, have only the
alveolar depressions for follicles ; that we may distinguish,
in this respect, three species of follicles which exhibit
three different degrees of complication ; I'st, those which
pour out a fluid of very great activity, such as those in
the ostrich; 2d, those of man ard the other omnivorous
animals; 3d, those of which we find the type in the
Java swallow, which furnishes a matter that possesses
scarcely any solvent power, and has in return very evi-
dent nutritive properties. = sick
The secretion which takes place in the mucous glands,
united to that of the sebaceous glands, constitutes one of

es ADDITIONS TO THE

the three principal kinds of secretion established by M.
Chaussier in his synoptical tables, viz. the follicular
secretion. It differs in fact in many characters from
the perspiratory secretion or exhalation properly called,
as well as from the glandular, which it resembles in
others; Ist, as in the first, the secreted fluid appears to
be brought directly by the extremities of the arteries ;
2d, this fluid, after having remained a certain time in
the cavity of the follicle, and having no doubt been
elaborated there anew, is thrown out, as in most of the
glands, by the peculiar action of the organ which has
furnished it.

Development of the Mucous System.

Page 125.—“ The development of the mucous sys~
tem follows in general the laws of that of the organs
to which it belongs. Early in the gastric apparatus,
later in the pulmonary and that of generation, it seems
in its growth rather to obey the impulse it receives, than
to give one to what surrounds it.’’

The arrangement of the mucous system is very differ-
ent in the first periods of conception, from what it will
be afterwards. ‘This system appears to be continuous at
this period, as well as the cutaneous, with the membranes
of the ovum ; such at least seems to be the result of the
observations of Wolff, Oken, Meckel and others.

Wolff has traced the development of the intestine in
‘the chick.. He has seen that this canal is at first very
‘short, straight, open before, and continuous in this direc-
tion, with the vitellary membrane, not having any very
precise limit to indicate the place where one terminates

and the other begins; that afterwards a contraction de-

i
f~ ,

typ
we ae

MUCOUS SYSTEM. 218

follicles. This is rendered still more evident in diseases,
as we shall see in the article upon the dermoid system.

Thus the mucous follicles must have a structure analo-
gous to that of the mucous glands of which they form
a part, though it is difficult to perceive this structure ;
they have no excretory duct ; only when they are situat-
ed below the chorion, in the subjacent cellular texture,
the neck of them being more or less elongated, forms a
kind of tube. The orifice by which they terminate is
uniformly more narrow than their bottom, and furnished
with villi similar to those of the neighbouring parts. Sir
Everard Home has given very good drawings of these
different objects.

Most of these small bodies are insulated and irregularly
disseminated, in greater or less number, in the whole
extent of the mucous system. I say in the whole extent,
for we have seen where they are but little apparent,
analogy induces us to admit their existence because secre-
tion is constantly going on there. Besides, their size
being excessively variable in the parts which are mani-
festly provided with them, it is natural to think that if
they are not seen in the others, it is simply because their
size is such as to conceal them from the sight. More-
over, what reasoning indicates, is already in part proved
by inspection ; the microscope has enabled us to see
follicles in many membranes in which they could not be
distinguished by the naked eye, especially in the pituitary
membrane; there is produced on the skin little bunches,
tumours formed by the development of the follicles, in
places where they had not been before met with, &c. But
in some parts, the follicles, far from being thus insulated
and often discoverable with difficulty, are agglomerated
and constitute by their assemblage masses of different
forms, and the arrangement of which varies; it is this

214 ADDITIONS TO THE

whieh has led to the distinction of the follicles inte
simple, which.are the first, and into. compound, among
which are ranked the caruncula lachrymalis, the folli-
cles of Meibomius, the arytenoid glands, the amygdala,
the molar. and buceal glands, the glandule agminate
of the intestines, the prostrate, &c.. Sometimes each of
the simple follicles which compose these last, has its own
orifice open'upon the mucous surface, as is seen in. the
caruncle.. Sometimes, as in the glands: of Meibomius,
they open into each other, so that the last pours out the
product of the secretion of the whole. . Sometimes. their
openings are ‘met with at the bottom of a sort of fold
which the mucous membrane makes, an example of
which is furnished by the amygdale 3; the mucous lacunz
belong also to this last kind ; they may be considered, as
well as the mucous folds of the amygdala and the foramen.
cecum of the tongue, as great follicles which receive
smaller ones; this is very well seen in the urethra, for
example.» Finally, the molar glands and the prostate
have a real ramified excretory duct, like the glands;
thus these organs partake of the glandular nature, and
theirs seem. as it were, to hold the middle space between
this and that of the follicles properly so called.

The mucous membrane of the stomach, that of the.
oesophagus and of the small intestines exhibit, besides
these follicles, small superficial cavities, slight depres-
sions, which Hewson, who first observed them, ‘compares
to the cells of the bees, and designates this arrangement
by the name of the alveolar structure. These alveole
have been more recently. described by Sir Everard
Home; they can only be secn with a microscope; in
some. places, however, they are visible to the naked eye.
‘They do not appear to differ {rom the follicles but in this,
that their aperture is broader than their bottom, the fold

‘Y-4 fe pie Be A ff P ry f “s ies “) nA
GAP a C4 vf li Bare sp te % 24s

MUCOUS SYSTEM. 217

signates this place, which is elongated more and more,
in proportion as the intestine grows at the expense of
the yolk, so that at birth these two parts hold together
only by a narrow pedicle, which disappears completely
when the yolk has been entirely absorbed. Now, the
umbilical vesicle appears to perform in man, in the first
periods of the intra-uterine life, the same uses that the
yolk or the vitellary membrane does in birds ; many
direct facts tend even to prove, that it is in the same
relation as this last to the intestine, though it may be
very difficult to be sure of it, because these first periods
are passed very rapidly in the mammalia, and the fcetus
soon acquires another mode of existence, wholly different
from that of birds. However, Ist, the umbilical vesicle
is so much the larger in relation to the foetus, and~so
much nearer the umbilicus, in proportion as the embryo
is younger; 2d, the intestine is for a long time in
part contained in the base of the umbilical cord, and
afterwards sends sometimes an elongation which extends
to the umbilicus; at other times there is seen a small
duct detached from the umbilical vesicle, and directed
from the side of the umbilicus, for a certain distance,
along the cord; 3d, various anatomists have seen this
vesicle communicating with the intestine in feetuses of
the mammalia; 4th, Meckel says that he has met with
a similar communication, in man.

From all these considerations, it may be admitted,
with Oken, Meckel, &c. that what is evident in regard
to birds, reptiles and fishes, takes place also in man, and
that the alimentary mucous membrane, by being con-
founded with the umbilical vesicle, makes, in the be-
ginning, an integrant part of the ovum. The same may
be said of the genito-urinary membrane, the bladder

having intimate connexions with the allantois; the skin,

28

218 ADDITIONS TO THE

on its part, making a continuation with the amnios. From
this it results, Ist, that these organs are among the earliest
in their development, if they be not eyen formed before
all the other parts ; 2d, that the embryo is in nowise dis:
tinct from the ovum in the first periods ; 3d, that its two
integuments, viz. the external formed by the skin, and
the internal which the mucous membrane represents,
instead of imitating, as in the adult, a double continu-
ous sac, folded at its two extremities, are as it were
but two semi-canals whose circumference is wanting in
front.

The part of the intestine, which corresponds originally
to the umbilical vesicle, and which serves as a point of
departure for the development of the rest of the canal,
remains to be determined. According to Oken, it is the
cecum ; and from this point the vesicle sends two elon-
gations which form the stomachal and anal intestines.
Meckel thinks that it must be the ileum, because it is so
in birds, and because this intestine often exhibits appen-
dices which are regarded as remains of the vesicle, and
because moreover the cecum does not exist in all the
mammalia. It is evident that these are but conjectures.

Besides, if it be true that the mucous system com-
mences by having the arrangement we have pointed out,
great obscurity still hangs over the manner of its ulterior
development, and the way in which this semi-canal, of
a very limited length, open in its whole extent, is com-
pleted in front on the one hand, and is changed on the
other into a long tube, no longer holding to the vesicle
but by a narrow and almost impreceptible canal. It
has also been attempted to explain in another way the
formation of this system. Some have said that the
eavities which it lines are hollowed: out from without
inwards, and that it was the skin, by plunging gradually

~o

serneneeeernens ene Sette AE GEN

J
f

MUCOUS SYSTEM. | 219

into the substance of the embryo, which gave rise to
the mucous membranes ; it is on this account, say they,
that the intestine is subject to interruptions in its continu-
ity, when its two portions, going, one from the mouth,
and the other from the anus, are not perfectly united.
There is nothing to prove this assertion, which is also
contrary to many facts.. Lucae has given another hy-
pothesis, founded upon this, that the cavity of the intes-
tine is often interrupted in many places; this proves,
according to him, that this canal is at first composed, like
the vessels, of insulated parts, which afterwards go to
meet each other, and are finally confounded. The ap-_
pendices of the intestine are formed: when these parts,
instead of joining to the end, are united together by
one of their sides. Tiedemann and Meckel admit this
opinion to a certain extent, modifying it in that part
which makes the intestine proceed from the umbilical
vesicle. On the whole, it appears that new researches
are required on this point; only the occlusions of the
intestinal tube do not appear to’me by any means to
demonstrate what authors have advanced; these occlu-
sions do not take place till after the complete develop-
ment of the intestine.

There are neither mucous villi nor folds in the first
periods of conception. Meckel states that the villi com-

_ mence by longitudinal folds, which are afterwards divid-

ed into small.insulated prominences, to form them.

a

220 ADDITIONS TO THE

MORBID ANATOMY OF THE MUCOUS SYSTEM.
I. Alterations in the External Forms.
The mucous ducts are dilated and contracted under

many circumstances; most of these have been noticed
in the article on the Properties of Texture of this system.

_ These changes of dimension in diseases almost always

depend on an obstacle to the course of the substances
which pass through these ducts in a state of health ; this
is evident with regard to the excretories ; the least exten-
sible, such as the urethra, may form, in this case, sacs or —
dilatations of more or less considerable size, before break-
ing; the bottom of the mucous lacune appears to be
sometimes the particular seat of these dilatations. Some-
times the obstacle is foreign to the mucous membrane,
and this contracts below only because less fluid passes
over it, and keeps it separated; sometimes the. contrac-
tion primarily occupies this membrane, whether owing
to. wounds, ulcers, inflammation or any other cause.
In either case, as in that in which the fluids take another
direction, because an accidental opening gives passage to
them, the portion situated below is not obliterated, as
has been seen.

The mucous membranes are however capable of con-
tracting adhesions; but for this it is necessary either
that the secretion of mucus should be suspended there
by inflammation, or that the epidermis, of those which
have one, should be destroyed. It is under analogous
circumstances that the tongue has been seen to adhere
to the corresponding parietes of the mouth, the vagina
to disappear by the mutual adhesion of its parietes, the

{

MUCOUS SYSTEM. 29%

Fallopian and Eustachian tubes, the nasal and lachry-
mal ducts, &c. to be obliterated. These adhesions are
however much less common here than in the serots
system. 3

The mucous membranes are the seat of thickenings,
growths and excrescences, which may be regarded as
enlargements of their substance. Polypi are an altera-
tion of this kind; they are divided, as is well known, into
many species; many belong as much to the sub-mucous
cellular texture as to the mucous membrane itself, which
they only raise up; there are some which arise from the
periosteum situated in certain places below the mucous
membrane, and whieh are real fibrous bodies; some are
formed by a texture which differs more or less from. the
natural one, and come, in this respect, under the altera-
tions of texture; such are those that are called cancerous. -

Various organs, that are covered on the interior by
mucous membranes, are exposed to defects of situation
and figure in which these membranes participate ; but the
latter have also some which are peculiar to themselves, ex-
amples of which are furnished in the various displacements
which the mucous membranes of the rectum, vagina, blad-
der, &c. experience in the prolapsuses, inversions, mucous
hernias, &c. of these organs. The internal or villous coat
which lines these viscera on the interior then leaves the
other coats, and is extended alone to a certain extent,
either through a natural opening, or through a preterna-
tural one arising from a separation of the fibres of the
nervous coat. The preternatural anuses are almost always
complicated with this sort of displacement to which the
mucous system is peculiarly disposed from the slight
adhesion of its subjacent texture, or nervous membrane

of the ancients, to the mucous membrane “ the organs
which it contributes to form.

222 ADDITIONS TO THE

y

II. Alterations in the Organization.

Inflammation produces in the mucous system, besides
the alterations of colour and the vascular development
which are peculiar to it, suppurations, false membranes,
ulcerations, gangrene, &c. Of all these phenomena, no
one is more remarkable than the formation of the false
membranes, analogous to what takes place in the serous
membranes. The conjunctiva in ophthalmias caused by
the vapour of the hydro-chloric acid, the rectum in irri-
tating injections administered to animals, the mucous
membrane of the mouth and the pharynx and that of the
air tubes in croup exhibit this alteration, in which a soft
layer, like the skin of pork, whitish, and slightly adherent,
covers more or less uniformly the inflamed mucous mem-
brane. This layer has hardly ever time to be organized ;
it is thrown out before, or the inflammation is quickly
fatal ; Albers has found it vascular in croup of a chronic
character. 4

In some cases, inflammation seizes more particularly
upon the mucous follicles, which swell and then become
very apparent; this variety has been described by Roed-
erer and Wagler. Another form which this affection ex-
hibits, though less evidently than on the skin, is that of
exanthema ; itis observed especially in those parts of this
system that are in the neighbourhood of the surface of the
body. ;
The solutions of continuity of the mucous membranes
cicatrize like those of the skin; this is what is seen in
some ulcers of the mouth and pharynx, after the excision
of execrescences from the genital parts, &e. The new
texture that is formed is whiter and more resisting than

j

MUCOUS SYSTEM, 223

the first; it sometimes forms filaments which may become
troublesome.

In the cases cited, (in vol. 3d, of Bichat,) the mucous
system finally experiences the cutaneous transformation
as this takes place whenever it is in contact with the ex-
ternal air ; its surface is then dried, the mucous fluids
cease to lubricate it, the villi disappear, an appearance of
epidermis takes their place, and the membrane becomes,
in some measure, more stiff. Various parts of this sys-
tem can also be changed into cartilages; we have cited
examples of this when treating of the cartilaginous system.

Cancer is very frequent in the mucous system ; it ap-
pears under many forms; Ist, it constitutes excrescences
similar in appearance to polypi, but very different in
their nature ; the rectum, the nasal fossz and. the uterus
are subject to these tumours. 2d. Other tumours are
subjacent to the mucous membrane, which finally par-
takes of the disease, and ubserates at their surface; can-
cers of the stomach, the oesophagus, the intestines and
the bladder most often assume this: form. 3d. Finally,
cancerous ulcers have their primitive seat in the mucous
system, begin on its superficies, and arrive, not for a long
time, to the deep parts ; but little engorgement accompa-
nies them; this variety is common on the lips, the glans
penis, and especially on the neck of the uterus.

Ill. Alterations in the Development.

Every organic system may be,considered in two ways,
as may be seen in the systems previously studied, in rela-
tion to the alterations that may take place in its develop-
ments ; 1st, this development is sometimes irregular in
the places where it should take place naturally ; hence
the defects of conformation, the anatomical varieties and

904 — ADDITIONS TO THE

the anomalies of every kind. 2d. At other times, it
takes place preternaturally, where it ought not to take
place at all, it invades other systems; hence organic
ransformations and productions. The alterations of the
first kind are produced by causes that are still but little
known, by obstacles. which have arrested the natural de-
velopment at one of its periods, and have thus preserved
forms which should be only transitory, by diseases that
the feetus has experienced in the womb of the mother,
and perhaps, in some cases, by an original mal-formation
of the germ, &c. Those of the second kind take place
almost always in diseases ; sometimes they are owing to
the progress of age. But among the different systems,
there are some which appear to be susceptible of one
kind of alterations only, or at least to which one kind
alone is common, whilst others experience both equally,
so that they might in this respect be classed in two orders ;
Ist, on the one side would be: the cellular system, which
has so great a tendency to be produced preternaturally
and so little to have defects, of conformation, and the
serous, synovial and fibrous, which are in the same situa-
tion; with regard to the nervous, the museular and the
glandular, the reverse is true, this: would require a subdi-
vision; 2d, on the. other side, the osseous, the arterial,
venous, &c. . Now the, mucous system belongs rather to
this last order than to the first,

Its defects of conformation are numerous. All the
mucous canals, without excepting the intestines, are sub-
ject to deficiencies to a greater or less extent, and some-
times exhibit in their course interruptions the seat of
which varies; sometimes it is at their exterior aperture
that they are found imperforated ; sometimes it is farther
in that their cavity is obliterated, either owing to the
parietes. being confounded together or closed by a sort of

F

MUCOUS SYSTEM. 225.

membrane, or because the canal itself has entirely disap-
peared. These canals are sometimes deficient in a part
of their circumference, which then exhibits preternatural —
openings, fissures and communications ; it is in this way
that the vagina is seen opening into the rectum ; the blad-
der, destitute of its anterior parietes, communicating with
the hypogastric region, which is itself destitute of parie-
tes; the urethra opening into the perineum; the palate
establishing a communication between the mouth and the
nasal fosse, the velum pendulum separated in its middle,
the lips divided asin hare-lip, &c. These alterations are
often only the remains of an unfinished, natural develop-
ment; this is evident in the hare-lip, the extroyersion
of the bladder, &e.

We should not forget, in the anomalies of development
of the mucous system, the digitiform elongations or
digital appendices of the intestine. These elongations
are formed by all its membranes; we have seen above
the attempt that has been made to explain the mechanism
of their formation. There is sometimes found, towards
the point of junction of the pharynx and the oesophagus,
similar appendices which retain the aliments, which occa-
sions a sort of rumination; these appear to be consecu-
tive and formed by a hernia of the mucous membrane
across the fibres of the nervous coat. Calculi of the
bladder are often lodged in cavities produced by the: same
mechanism.

We may consider as preternatural mucous membranes,
ist, the membrane which lines the interior of abscesses ;
2d, that of old fistulous canals.

The membrane of abscesses, though belonging to cavi-
ties closed on all sides, has in fact more points of resem-
blance to the mucous than to the serous membranes ;

follicles, it is true, have not been described in it ; but its
29

296 ADDITIONS TO THE MUCOUS SYSTEM.

surface is soft, pulpy and fungous, like that of the mucous
membranes; when put in water, it seems, like these last,
to be covered with filaments. The analogy of seeretion
is an additional reason in favour of this resemblance ;
what is more analogous to mucus than pus?

The resemblance is still more evident in sinuses and fis-
tulas terminating on the exterior. Hunter had already
noticed this resemblance, upon which Bayle, Laennec and
others have more particularly insisted. ‘The membrane of
the fistulous canals has a distinct epidermis in the neigh-
bourhood of the skin; farther in, it disappears, and the
membrane becomes red, soft and fungous; it would be
difficult, in this place, to distinguish it from a portion of
mucous membrane taken from the sinuses, for example ; it
has no follicles, but its fluid is almost of the same nature;
below it, the cellular texture is often hardened and more
compact than in the natural state, as is seen in callosities ;
it is a result of inflammation; this texture is sound when
the inflammation is slight. When every thing ceases to
pass through the fistula, it contracts and its canal closes ;
it differs in this from the mucous ducts, which are not ob-
literated under the same circumstances ; but its oblitera-
tion is not always easy, especially in the neighbourhood
of the skin, and in general fistulous canals have but little
tendency to cicatrization; thus we endeavour by every
method to.develop. inflammation in them or to destroy
the membrane which covers them. |

In abscesses, as in fistulas, the preternatural ineealibdes
derives its origin from the cellular texture, and is owing
probably to an albuminous exudation of the nature of that
which constitutes false membranes.

ADDITIONS

SEROUS SYSTEM.

MORBID ANATOMY OF THE SEROUS SYSTEM.

The alterations of this system have been already in
part pointed out by Bichat; the following is what we
shall add to what he has said of them.

I. Alterationsin the External Forms,

Sometimes the serous membranes thicken at t’> same
time that they are increased in extent, as is s» espe-
cially in hernias and dropsies ; this increase in all direc-
tions supposes a real increase of nutrition in them ; this
cause then should be added to all those which facilitate
the extension of these membranes, as their‘ displacement,

228 ADDITIONS TO THE

the disappearance of their folds and their peculiar exten-
sibility. (See in the Serous System the article Exten-
sibility.) In other cases, the thickness of these mem-
branes is so much diminished by distension, that often-
times they are found with difficulty. This is not rare
in umbilical hernia.

The serous system is subject to various displacements,
which alter more or less its configuration. These dis-
placements are most often only secondary, and are owing
to changes that take place in the viscera which this
system covers, or in the parietes of the cavities which
contain these viscera, parietes upon which it is also
spread; they are consequently of the same nature as
those which the various functions produce in the natural
order. Now these displacements take place in three
ways; Ist, the serous membrane leaves the parietes and
goes upon the viscera; 2d, it leaves these last to go
upon the first ; 3d, it extends without the parietes, forms
a sac, which is united to the general sac that it forms
within; this sac is constituted by the portion that lines
the parietes; but in time the membrane is also detached
from the viscera, or draws them out when it adheres to
them too strongly. The sae of which we are speaking
is produced whenever a viscus, forced through the pari-
etes of its cavity, carries at the same time before it the
serous covering of these parietes ; this is the sac of her-
nias, the hernia? sae properly so called. But in some
cases, this sac exists previous to the hernia, and the
viscera are not connected with it till afterwards ; this is
what takes place when fat accumulates on the exterior of
the peritoneum for example, and finally forms a mass, the
situation and weight of which draw it outwards, and
which also draws the serous membrane with it, so that
this forms a sac ready to receive the viscera on the first

<

SEROUS SYSTEM. 229

occasion ; an arrangement very improperly known by
the name of fatty hernia. It is important to know in
practice the displacements of the serous membranes, be-
cause they often change the relation of the parts ; the sac
of hernias, in particular, presents many points for study.

Il. Alterations in the Organization.

The most of those which are the consequence of
inflammation depend on changes which are experienced
by the fluids that are naturally exhaled in the serous cavi-
ties, changes which vary according as the inflammation
is acute or chronic. These fluids may be simply in-
creased in quantity, and preserve all the qualities of the
serous fluids, or they may be altered in various ways 3.
from this simple serum to opake pus, destitute of glo-
bules like that of the cellular texture, there is an infinity
of gradations. Most often a matter capable of concretion
is produced, either albuminous flakes swim in the effused
fluid, or a layer of the same nature, a false membrane,
distinet from this fluid, covers the inflamed serous mem-
brane, or this layer, interposed between the two folds of
the serous membrane not separated by an intermediate
fluid, establishes between them an adhesion, soft and glu-
tinous, similar to what is formed between the lips of a
wound united by the first intention. The false mem-
branes begin by insulated points of albuminous matter,
deposited at first only in the most inflamed places, after-
wards united together, and then forming a continuous
layer, the thickness and consistence of which vary. This
layer adheres but slightly to the membrane which fur-
nished it; but there is observed, when itis detached from
it, that a sort of indentations, reciprocal inequalities unite
one to the other; under it, the serous membrane is usually’

230 ADDITIONS TO THE

red and penetrated with vessels. From the production
of these false membranes, and from the soft and skin-like
adhesion which is but a slight modification of them since
it only differs from them by the absence of a fluid suit-
able to maintain the separation of the folds of the serous
membrane, are derived all secondary effects of inflamma-
tion, both acute and chronic, all the varieties of thicken-
ing and all the modes of adhesion. The albuminous or
skin-like matter of the false membranes, which thickens,
hardens, is organized and penetrated with vessels, occa-

sions these varieties, by the variable forms it assumes at —
the moment it experiences these changes; we shall not

revert to the manner in which they take place; the de-
velopment of the vessels, which is the main point, has
been examined in the capillary system. We may now
understand how miliary granulations, opake, whitish,
sometimes extensive and supported by a narrow pedicle,
cover the serous membranes after their inflammation,
the evident result of the concretion of albumen on their
surface ; how layers of the same nature are seen, under
the same circumstances, upon the pericardium, the arach-
noides, the tunica vaginalis, &c.; how these different
membranes, the pleura and peritoneum in particular, often
acquire in chronic inflammation, a thickness double or
treble that which they before exhibited ; a thickness
which is only owing to the presence of the false mem-
branes organized and intimately united with these mem-
branes, and which should be distinguished from that
which is owing to a real increase of nutrition ; how the
cellular and filamentary adhesions arise, those in which
the two folds of the membrane are entirely confounded,
and the filaments, &c. according as the albuminous matter
is stretched a little or not at all, or as on the contrary,
this matter has been subjected by the motions of the part

wR

SEROUS SYSTEM. 231

to frequent distensions, according as the inflammation
has continued for a longer or shorter time and the or-
ganization has been more or less perfect, &c. &c.

A cicatrix arises from the serous system when divided,
though it was doubted for along time. It is linear and
afterwards imperceptible when the edges of the wound
have remained in contact, and it is a cellular membrane
analogous to the texture whose place it supplies when these
edges have not been properly brought together; we may
be convinced of this fact by examining the pleura of an
animal which had been opened some time before. Thus,
in the hernias which succeed to the old wounds that pene-
trate the abdomen, the peritoneum forms, as usual, a sac
for the displaced viscera, though the contrary has been
for a long time maintained; only this sac is more delicate
and seems to be entirely formed by the cicatrix which
remains more extensible than the neighbouring texture.

The serous membranes are ossified ; no one is exempt
from this alteration, which appears under many forms.
They are usually plates appearing rather to raise,up the
membrane than to belong to it; sometimes, however,
these plates are almost naked on the interior of this
membrane. The tunica vaginalis, the pleura and. the
peritoneum contain also, in some cases, a species of con-
eretions similar to those of which the synovial system is
the seat, and to which we shall revert.

M. Laennec has described, in his treatise upon us-
cultation Médiate, tumours of the pleura which he
refers to the cerebriform cancer; they occupy the in-
ternal face of this membrane, to which they adhere
strongly ; their environs are marked by a slight redness
owing to the development. of the blood vessels ; they
are usually in small number. There is often found, in
intestinal ulcerations, particularly those which take place

232 ADDITIONS TO THE

in phthisical patients, small miliary tubercles which make
a part of the serous membrane at the place of these ulcer-
ations. Various authors have spoken of schirri of the
serous membranes ; but they no doubt intended to desig-
nate by this name thickenings, the result of inflammation,
and not a true degeneration.

Ill. Alterations in the Development.

The defects of conformation are quite rare in the sys-
tem of which we are treating. The peritoneum, the
pleura and the pericardium, instead of representing a sac
without an opening, are sometimes open in front, and
are destitute of the exterior lamina to a certain extent,
so that their viscera are bare. The arachnoides has a
very imperfect organization in the aencephalous fcetuses ;
but this defect is but a consequence of that which then
exists in the brain, The peritoneum has exhibited, in
some rare cases, a sort of vesicle or secondary sac situ-
ated in its interior, communicating with it by a nar-
row opening and containing a part of the abdominal
viscera. 7

Bichat was the first who satisfactorily proved the anal-
ogy which exists between the cysts that are preturnatu-
rally formed in various parts of the body and the serous
membranes. (See the Cellular System, Vol. 1st, and
the Serous System, Vol. 3d.) He has refuted the opinion
of Louis upon the mode of origin of these cysts, which
he regards as always existing prior to the substances they
contain. It is necessary however to make a distinction
here ; in fact, lst, there are cysts that are really pre-
existent, as all those that are called mediceris, atheroma
and steatoma; but these are only sebaceous follicles

f
SEROUS SYETEM. 233

exceedingly dilated, as we shall see in’ another place ;
(Vide the Dermoid System ;) the eysts of the ovarium
are perhaps also in the same situation, as they appear to
be owing only to preexisting vesicles; 2d, there are
evidently consecutive ones, which are formed around
various bodies coming from without, around the blood
in apoplexy and pus in chronic abscesses ; 3d, the origin
of a great number is obscure, to which the observations

offered by Bichat apply perfectly. )

On the other hand, the organization of eystis is far from
being the same, though in “general they belong to the
serous system.” Some are soft and almost fluid, as ‘it
were; it seems as if they were the result of a simple
exudation ; sore of this species have been found in the
brain. At other times itis a membrane but little differ-
ent from the cellular texture; in some cases, on the con-
trary, it is a real serous cavity, very, distinct from this
texture, as is seen on the neck, and in the spermatic cord.
There are some, the structure of which resembles that
of the mucous membranes; others have a slight resem-
blance to the skin. These cysts are moreover susceptible
of various transformations ; they become fibrous, carti-
laginous and osseous ; the cancerous and other degenera-
tions are also met with in them.

The substances contained in these preternatural sacs
are infinitely various. Solid, foreign bodies, blood, lim-
pid serum, viscid, gelatinous or mucous matter, serous
fluids mixed with albumen that is capable of concretion
and that which is not, fatty fluid matters, or those with
different degrees of consistence, a pultaceous, stony or
cretaceous substance, and coneretions more or less ‘hard
may be contained in them. Authors have been much
engaged in explaining these differences, which are often
observed in cysts that are analogous it in structure. They

30

&

234 ADDITIONS TO THE

have been in general attributed to causes purely mechan-
ical. It is thus that Bostock, who has examined the
matter of many cysts found in the interior of the pelvis,
after having praised Cullen for rejecting these explana-
tions, proposes himself one of this kind, by which, ac-
cording to the state of the heart and the modifications
which result from it in its action, according to those
which the animal heat experiences or the disposition of
the small vessels, there would pass through these last,
sometimes the serum of the blood almost pure, some-
times this serum, with a proportion of albumen, either
in a fluid or concrete state, sometimes these two matters
united to fatty matters under various forms, and all the
substances in fact which are found in cysts. It is evident
that the mechanism of exhalations is too little known, for
these explanations to be accurate; the causes mentioned
may no doubt contribute to the production of the phe-
nomenon, but they assuredly do not alone constitute it.
Hydatids resemble cysts in their apparent structure,
though they are very different in their nature ; this is so
true that authors are not often agreed upon what should be
called cyst and what hydatid. The following however are
the principal characters by means of which they are dis-
tinguished ; 1st, cysts are attached to the surrounding parts
by cellular texture and blood vessels; hydatids, on the
contrary, are perfectly free ; it is true, that in some cases
cysts are found hardly adherent ; but these cases are rare.
2d. The parietes of the cyst have always more or less
consistence; the hydatid has only that of the white of
an egg boiled. 3d. The hydatid often exhibits in some
point of its surface, something like little grains which
are discoverable by the naked eye or with a glass, and
which seem to be the rudiments of other hydatids ;
nothing similar is seen in cysts. Notwithstanding these

SEROUS SYSTEM. 235

differences, which are striking, there are cases where
it is difficult to decide, to which kind of productions they
belong ; this is almost always the case, for example, in
the vesicles of the plexus choroides, and’ still more in

the masses of the same kind which are situated in the ~

placenta, and the nature of which is still very doubt-
ful. .

ADDITIONS
TO THE

SYNOVIAL SYSTEM.

|

Of the Synovial Membranes.

Page 179.—‘‘ From these different considerations we
may be easily convinced, I think, that notwithstanding
the adhesion of the synovial membrane at different points,
it should be considered... as a real sac without an
opening, everywhere continuous and spread upon all the
organs of the articulation.”

The reality of this arrangement, already recognized by
Nesbith, Bonn and Hunter, and which some persons
have doubted, is also. proved by the following considera-
tions.

238 ADDITIONS TO THE

Ist. In inflammation of the synovial membrane, the
redness, beginning on the free portion of this membrane,
extends gradually from the side of the cartilage, the
surface of which it finally reaches, nearly as in ophthal-
mia, the conjunctiva reddens gradually upon the globe
of the eye, according as it is near the centre of the
cornea. This gradation is easily observed in dogs, in an
articulation that is opened, and the interior of which is
left in contact with the air. The redness, in this ex-
periment, never reaches the substance of the cartilage ;
‘it is confined to its surface, and is, as it were, foreign
to it.

2d. There isa continuity of vessels between the kind
of capsule which the membrane forms around the osseous
surfaces, and the surface of the cartilage, as is evidently
seen in the preceding experiment. The synovial mem-
brane of the knee, injected in this way, exhibits, in its
adipose ligament, vessels which extend directly in its
portion which covers its cartilage, to the two extremities
of this ligament.

3d. If a bone be divided sicidbak Alliage at its articu-
lar extremity, by leaving untouched the cartilage of this
extremity, and if, by the separation of the two halves of
the bone, the cartilage be afterwards ruptured, the two
fragments “Still hold together by the synovial membrane
which passes from one to the other. It is the same
when the surface of a cartilage is broken, and the piece
raised up, so as to break it at its base; this piece still
adheres by means of the synovial membrane, which has
not been ruptured.

Let us conclude from these different facts, that the
synovial membranes, far from being limited to the circum-
ference of the articulations, go to the whole extent of the
osseous surfaces, upon the cartilages which cover these

¢

SYNOVIAL SYSTEM. 289

surfaces, and really constitute sacs without an opening, in
every respect similar to those of the serous membranes,
as has been very well seen by Bichat.

Synovial Fringes.
»

Page 181.—‘‘ If a remarkable redness sometimes
distinguishes these bunches” (the pretended glands of.
Havers) “ from the cellular texture, it is because the ves-
sels are more concentrated and nearer together in them.
This redness of some pretended synovial glands, the only
character that distinguishes them, is then as it were
merely accidental; it no more indicates their glandular
nature, than it proves it in the pia-mater, in which it is
owing to the same cause.”’

_ What is here said of the fatty bunches so improperly
ealled glands of Havers, may be also said of the synovial
fringes which surmount these bunches, and the vascular
structure of which does not prove that they are excretory
ducts. These fringes, very well described and drawn by
Monro, are folds of the synovial membrane floating in
the articulation, and precisely analogous, in this respect,
to the epiploons of the serous membranes, and the epi-
ploic appendices of the intestines. These folds are
grooved on their surface, have their free edge cut in
various ways, as can be very well seen by floating them
in water, and resemble in some measure fringes ; hence
the name that has been given to them, and which may be
retained, though it by no means expresses their nature.
Between the two laminzw of these folds, and in these
lamine themselves, there is a great number of vessels,
arteries, veins, exhalants, and no doubt absorbents also ;
thus the synovial membrane is much redder there than

240 ADDITIONS TO THE

any where else. It is to the presence of these vessels, the
exhalants in particular, that the following phenomenon is
owing, which may have deceived Havers; if these folds
are pressed, synovia oozes out of them, which evidently
comes from the open exhalant orifices, and not from par-
ticular ducts.

All the synovial membranes have these elongations,
both those which belong to the tendons and those destined
to the articulations, although they are more evident in
the last than in the first; among these, those in the form
of vesicles have them more constantly than those in the
form of sheaths. The great articulations, as those of the
knee and the hip, contain the largest ; in the small ones
they are often only reddish points slightly prominent.
They are in general situated near the place where the
synovial membrane is reflected around the articular carti-
lage, and usually correspond to the adipose texture of
the synovial bunches, in part contained in their substance;
those of the tendinous synovial membranes haye often
between their lamin, instead of this texture, soft bodies

like gelatine, the fatty bunches analogous to the articular
‘ones called glands of Havers being wanting in many of
these membranes.

The synovial fringes, from the great number of vessels
they contain, are the especial seat of the secretion of
synovia. This secretion is perspiratory, and evidently of
the class of exhalations; it only takes place there more
than in any other point of the membrane, because ne
exhalants are more numerous there.

The following is the idea that should be formed of
synovial fringes and bunches; Ist, blood vessels sur-
rounded with a more or less abundant adipose and cel-
lular texture; 2d, folds, which embrace them and in
which they particularly terminate; folds more or less

SYNOVIAL SYSTEM. 241

numerous, more or less extensive, and whose surface
pours out synovia in abundance.

The mucous system exhibits something analogous to
the fringes of the synovial membranes in the folds which
exist under the tongue, and upon the sides of the frenum
of this organ; these folds are real secretory fringes, de-
signed to increase the extent of the exhalant system.
Parallel between the Synovial Membranes and the

Serous ones properly so called.

Page 181.—* Though the synovial membrane is very
analogous to the serous surfaces, it must however exhibit
differences of texture, since the fluid it exhales is a little
different. Its texture has not the suppleness of theirs.
It resists maceration longer.”’

The synovial: membranes might justly be called the
serous membranes of the articulations and the tendons ,
yet the difference of the parts which they invest gives
them peculiar characters. Most of these characters have
been stated; the following are some more of them.

The synovial membranes receive fewer sanguineous
and other vessels, than the serous membranes. These
appear, as it were, to be entirely formed of vessels in
inflammation, after fine injections, &c. ; the synovial
membranes contain much fewer under like circumstances.
Compare the deep tinge of the serous membranes in
asphyxia with the much less evident one of the synovial
membranes in the same case, and you will be struck with
this difference. The lymphatics are in immense quan-
tity in the serous membranes, as is shown by injections ;
we admit them from analogy, and only on account of
their functions, in the synovial membranes.

31

248 ADDITIONS TO THE

Maceration discovers in these distinct lamine and
fibres ; the serous membranes have them also, but theirs
are much less apparent.

The synovial membranes, especially those of the artic-
ulations, are less extensible, and seem to be torn sooner
than the serous ones; at least ruptures are more frequent
in them than in the latter, This difference is owing per-
haps solely, or in great measure, to this, that the connex-
ions of the membranes are not the same, any more than
the causes which distend them; the one fixed to the
bones, and strongly drawn by these organs, must yield
and break, as happens in luxations, the others, in relation
with the soft parts and capable of yielding themselves,
are merely elongated, as is seen in hernias.

Existence, Forms, Organization, §c. of the Synovial
System of the Tendons.

Page 191.—* There are many synovial membranes the
existence of which is variable; such as, for example, that
of the great gluteus, in the place of which there is often
found only a cellular mass.’’

In this respect, viz. that some parts of this system are
sometimes wanting and are then replaced by cellular tex-
ture, the synovial system of the tendons is confounded,
more perhaps than the serous and the articular synovial,
with the cellular. . But, besides the latter resembles in
many places, in its arrangement, the mucous burse or
synovial. membranes of the tendons. Wherever great
motions take place, the cellular texture is loose, lamel-
lated and filled with fluids ; its laminz are separated by
broad interstices, imitating more or less exactly the cav-
ity of the serous or synovial membranes, so that it may

SYNOVIAL SYSTEM. 243

truly be said, that these membranes exist in rudiment
wherever there is this kind of motions. This is what is
seen on the thigh, between the tendon of the anterior
rectus and that of the triceps, between the biceps and the
anterior brachialis on the arm, &c. There is a sort of
gradation according to the mobility of the parts, in this
arrangement of the cellular texture; the integuments of
the back of the hand, those which cover the anterior face
of the patella, the olecranon and acromion have under
them, on account of their frequent sliding, a cellular tex-
ture which resembles that which is found around the ten-
dons, sometimes even true mucous burse. Finally, where
the frictions are very evident, as between the tendons
and the bones, these are nearly constant. They are found
almost uniformly, with a greater or less degree of devel-
opment, between the skin and the bones, in the places
where these parts have frequent motions, as at the elbow
and the knee, so that in those places there are generally
sub-cutaneous mucous burs, as there are tendinous ones.

There is a circumstance which may also have an in-
fluence upon the existence and number of the tendinous
synovial membranes ; it is that some are sometimes in-
sulated, and sometimes confounded, as is seen in those
which line the sheaths of the tendons, according as these
sheaths are themselves separated or confounded together.

Tn order to see these membranes well when they exist,
we raise the tendon below which they are to be found,
open them to a small extent, and force into this opening
air or the matter of injection ; they are distended and then
become very apparent, and distinct from the surrounding
cellular texture; or we may be content with opening
them with care; the moisture and polish of their surface
serve to distinguish them.

244 ADDITIONS TO. THE

The tendinous synovial membranes exhibit some
differences in their forms, besides the general division
into vesicular and vaginal pointed out above. Their
cavity, instead of being simple, is often medtilocular,
(having many cells,) divided by elongations which are
detached from their interior ; these clongations are
usually soft, but in some cases fibrous. The vaginal
mucous burse have one of their extremities divided in
the manner of digitations, when many tendons, united at
first in a single sheath, are afterwards separated, &c.

These membranes have, as we have said, fringes and
sometimes even synovial bunches on their interior.
Fourcroy and Koch have seen yilli in them. The vesi-
cular synovial membranes are of a texture more dense
and compact than the vaginal, and nearly fibrous in some
points.

Their fluid is yellowish, sometimes reddish ; but then
this tinge is accidental, and generally a result of the
transudation which takes place after death. It appears to
be thinner in the synovial membranes of small extent,
and which do not experience considerable frictions ;
thicker and more viscid in the others, in that which
covers the great trochanter, for example, and whose
motions are very evident. This fluid has not been
analyzed ; it appears to be formed of water, albumen,
soda and perhaps some salts; it is miscible with water
in any proportion; heat and the acids coagulate it; it
turns the syrup of violets green ; when dried, it is trans-
formed into’ a kind of horny lamina, very thin, which
burns like the dried white of an egg.

The mucous burse are very extensible, as is seen when
they are inflated; dropsy also furnishes a proof of it.
They contract when the distension is removed.

SYNOVIAL SYSTEM. 245

MORBID ANATOMY OF THE SYNOVIAL SYSTEM.
I. Alierations in the External Forms.

The distension of the articular synovial membranes by
a collection of synévia constitutes hydarthrosis, an affec-
tion that is not common and which is observed especially
in the knee, which, in general, presents the most frequent
examples of all the. diseases of the articulations. The
quantity of the accumulated fluid varies, as well as the
nature of this fluid; this is dependant on the various
complications that may exist, as on inflammation in par-
ticular. The distension is usually more evident in one
or several points, where the synovial membrane is the
least supported by the surrounding parts.

Dropsy of the mucous burs is called hygroma when
its fluid is serous, colourless’ and limpid, and ganglion
when it is a reddish, thick and viseid matter, more or
less similar to currant jelly. Neither always have their
seat in the natural mucous burse; they are sometimes
preternatural tumours, a sort of cysts. It is thus that the
ganglions are formed upon the back of the hand though
there are no mucous burse in this place. The hygroma
is frequent in front of the patella, on the shoulder and
the elbow, places where the cellular texture is so closely
connected with the synovial membranes; it takes place
especially in persons who have these parts subjected to
constant pressure.

Anchylosis exhibits, as is known, many varieties. In
that which is called false and which should be considered
a distinct disease, all the parts which enter into the com-
position of the articulation are thickened. But anchylosis

246 : ADDITIONS TO THE

properly so called, affects especially the synovial mem-
brane. Sometimes filaments of various extent and con-
sistence traverse the articulation, and unite the two oppo-
site laminz of this membrane which covers the articular
surfaces ; a sort of amphiarthrosis then exists; an articu-
Jation with limited motion and with continuous surfaces
takes the place of the one which existed before with
great motion and contiguous surfaces ; it is to this first
variety that the name of false anchylosis may be given,
if it be desirable to preserve this distinction. ‘Sometimes
the adhesion between the two surfaces is intimate, the
synovial membrane disappears or is changed into cellular
texture, the bones are united together and are finally
deprived of the lamina of compact substance which
covered their extremity ; this is true anchylosis. These
two kinds of adhesion suppose here, as in the preceding
system, an anterior inflammation.

IJ. Alterations in the Organization.

Besides these adhesions, the inflammation of the syno-
vial membranes sometimes produces ulceration in them,
though it is quite rare; Mr. Brodie has related two
examples of it. In other cases, this inflammation termi-
nates by resolution, and there results from it only a little
stiffness and embarrassment in the motions, owing to the
thickening of the parts. It may also be followed by
suppuration and effusions of various kinds, though these
effusions are observed less. frequently than in the serous
system. |

The tendinous synovial membranes exhibit in their
inflammation, fortunately quite rare, the two modes of
adhesion which have been noticed, viz. filaments and

SYNOVIAL SYSTEN. 247

adhesions properly so called. They also suppurate at
other times, and then their tendons most usually exfoliate.

The foreign bodies of the articulations, which some
have taken for concretions formed in their interior, and
which others consider as broken and detached portions
of bone or cartilage, are always situated in the begin-
ning, without the synovial membrane. They are osseous
or cartilaginous productions deposited at first in the cellu-
lar texture, pushed afterwards by degrees, either by the
various motions or any other cause, into the cavity of
this membrane, in which they are enveloped and, which
they stretch prodigiously as they advance ; it terminates
by forming for them only a.sort of pedicle, which at
length becomes thin and finally breaks; when this rup-
ture takes place, the body is loose in the articular cavity.
The state which it then exhibits varies ; its consistence
is sometimes very soft and like albumen, at others carti- _
laginous or osseous ; in some cases the same body exhibits
these different states. The long continuance of these
bodies and the pressure which they exert, often produce
upon the articular cartilage, depressions or cavities in
which they are lodged; these depressions have led .to
_ the belief that there was a loss of substance of the car-
tilage, the detached fragment of which produced the
foreign body ; but we cannot conceive of. any cause
capable of producing such a separation, and besides, in-
spection does not confirm this idea.

Bodies of another nature are developed in the mucous
burs, and sometimes also in the articular synovial mem-
branes. They are usually extremely numerous, of the
size of a large apple seed, flattened in various directions
and of a whitish colour. They have been thought to be
animated, but they appear to be inorganic; their origin
is but little known. Monro has also found in’ the

348 ADDITIONS TO THE

{

mucous bursze small bodies of a peculiar nature. The
same author says that he has met with cartilaginous plates
in them. ¥

In white swellings, an improper term under which is
confounded various degenerations and the chronic inflam-
mation of the synovial membrane, this often becomes the
seat of a peculiar degeneration ; its texture becomes
thickened, greyish, like lard, homogeneous and surround-
ed with soft fungi, the presencesof which beneath the in-
teguments may lead to the belief that there is an abscess
on account of a kind of obscure fluctuation that is
thought to be felt there.

Ill. Alterations in the Development.

_ The membranes analogous to the synovial ones that
are met with in the supplementary articulations, the
consequence of luxations not reduced, are in. part formed
by the remains of the old one that is ruptured and in
part by the real production of a new texture. Fractures
that have not united sometimes have a capsule which
seems also to belong to the synovial system, inasmuch
as it contains a serous fluid, as we have said elsewhere.

The synovial cysts, which were mentioned at the be-
ginning of this article, are preternatural mucous burse.

The absence of some tendinous synovial membranes,
under some circumstances, is the only defect of confor-
mation peculiar to this system.

ADDITIONS

GLANDULAR SYSTEM.

ieeeiennale
—_—_———

Intimate Structure of the Glands,

Page 200.—* The glands, like all the other organs, ..
have their peculiar texture which especially characterizes
them, which belongs only to them, a texture in which
the arteries communicate with the veins and the excreto-
ries. Let us not push our researches further; if we do,
we shall be inevitably entangled in conjectures.”

Is the communication direct between the arteries and
the excretory ducts, or is there something intermediate
between these two orders of vessels ? The results obtain-
ed by Ruysh and Malpighi in the solution of this ques-
tion, though opposed to each other, are however equally

32

250 ' ADDITIONS TO THE

founded upon facts rather than upon mere conjectures.
Only these two anatomists, both alike commendable, no
doubt directed their attention to glands wholly different.
In fact, it is easy to see, by the description even of the
glandular system, that the organs which are comprised
in it, even by restricting as much as possible the term :
glands, and by applying it only to those to which it ex-
clusively belongs, by taking from it consequently the
mucous and sebaceous follicles or glands, of which we

have, spoken in the article on the Mucous System, and |
the glandiform organs, as the thymus, the thyroid, the
supra-renal capsules, &c.; it 1s easy to see, I say, that
these organs vary in their most essential properties, and
have at most only some general points in which they
approximate each other. Thus, as it regards structure, of
which we are now to treat, the opinion of Ruysh seems
to be perfectly applicable to some of these glands, the
liver, the testicles and the kidneys ; whilst, in respect to
others, such as the lobulated or conglomerated glands in
general, that of Malpighi has more probability in its
favour. Inspection and experiment may be resorted to ;
the one shows us, in the first of these glands, an evi- —
dent vascular arrangement in all the points of the organ,
a continuity that can be traced by the eye, if we may so
say, between the sanguineous ramifications and those of
the excretories; in the second, this arrangement is much
less distinct and it is impossible to discover the continuity
in most cases. By the other we see, in injections, the
rapid, easy and constant passage, in the excretory vessels,
of the matter driven in through the arteries in one class,
the liver, kidneys, &c.; this same passage, slow, difficult
and oftentimes wanting in ‘the others, as in the salivary and
lachrymal glands, pancreas, &c. It may then be possible
that the little grains that are perceived in the latter may

is f
' GLANDULAR SYSTEM. 251

be small bodies intermediate between the arteries, veins:
and excretories, as Malpighi thought, species of. follicles
in which the one terminate and from which the others go
off ; whilst every thing may be vascular, according to the
hypothesis of Ruysh, in the glands of the other kind.
Hence no doubt why the bloody excretions are very
much more frequent in the latter, especially in the kid-
ney, than in the first.

a
Influence of Nerves upon the Action of the Glands.

Page 223.—“If we weigh the proofs given by Bordeu
of the influence of the nerves on secretions, we shall see,
that they either rest upon false facts, like those of the
section of the nerve, of sleep, &c. or upon vague data.””

Every thing which relates to the peculiar action of the
glands is in general but very little known, as is the case
with all the phenomena which take place in the interior
of the organs. All that is known upon those of glandular
secretion is confined nearly to this ; blood containing the
materials of secretion arrives in the glands by the arteries,
except in the liver, which receives it from the veins and
the arteries; this blood, in traversing the glands, under-
goes changes in them in consequence of which a fluid
wholly different from it is produced. But do these
changes take place suddenly, or slowly and as the blood
advances in its course, and what is their nature? Are
they merely the result of the configuration of the parts
and a phenomenon purely mechanical ? Is it a chemical
or galvanic action which produces them, a doctrine which
seems to prevail at the present day in many schools? Is
it a consequence of the neryous influence, or finally do

4

252 ADDITIONS TO THE

all these causes contribute to it at once? This is what we
are ignorant of.

As to this last influence, that of the nerves in secre-
tions, it is probable that it exists, as Bichat says, though
it may be very difficult to be certain of it directly. The
division of all the nerves of a gland, suggested by Bordeu,
is almost everywhere impracticable. The experiments
related by Bichat will no doubt be found far from being
conclusive The following, which are perhaps scarcely
any more so, but in which however the results seem to
be a little more decisive, and which besides appear to be
so much the more remarkable, as they are in evident
eontradiction to the first, are made by Mr. Brodie.

Ist. The brain having been removed, respiration being
supported artificially, that the circulation might not stop
and that the animal might continue to live, the urine was
no longer secreted. This fact does not prove positively,
it is true, that the cerebral action has an influence upon
the function which the kidney has of secreting urine; for
it might be that the circulation was weakened in this case
so as to render the secretion less active; it is however a
strong presumptive evidence of this influence.

2d. In order to be able to appreciate the mode of influ-
ence of the nerves of the eighth pair upon the mucous
secretion of the internal coat of the stomach, a secretion
not sufficiently abundant in the natural state to enable us
to obtain striking results, it has been attempted to increase
the products of it by giving to an animal arsenic and
other poisonous substances of the class of corrosive
poisons, which produce, among other phenomena, an ac-
cumulation of the mucous and other fluids that are con-
stantly poured out on the internal coat of the stomach;
the nerves of the eighth pair have afterwards been divid-
ed. At the death of the animal, that mass of fluids is

,
:

GLANDULAR SYSTEM. 253

not found, which is never wanting under any other cir-
cumstance. It seems to follow from this that the integ-
rity of these nerves is necessary to enable the mucous
glands or follicles of the stomach to answer to the stimuli
which are directly applied to them.

MORBID ANATOMY OF THE GLANDULAR SYSTEM.

The extreme diversity that exists in this system makes
it almost impossible to describe in a general manner the
morbid alterations of the glands; there are too many
peculiarities belonging to the descriptive anatomy, and
too few common points; it would require almost as
many divisions as there are organs comprehended under
the name of glands; it is the same with regard to the
description of this texture considered in the natural state ;
what we shall now say will be a proof of it.

I. Alterations in the External Forms.

Increase of size as well as the circumstances under
which it takes place, have been noticed (Bichat, vol.
3d,) in the glands that are in pairs; the glands that are
not in pairs, like the liver, rarely experience it, without
it is joined with an alteration of texture.

Atrophy comes on in two ways, viz. 1st, from com-
pression, as from an external pressure long continued, or
when a tumour has gradually destroyed the interior of
an organ; 2d, from want of exercise, as takes place in
certain glands from the progress of age.

254 ADDITIONS TO THE

’ We know all the varieties of consistence, and all the
differences of colour which the liver exhibits in diseases.
The testicle and the kidney also present some of them
the other glands are much less subject to this kind of
alteration. | os

Displacements are observed in those of these organs
situated in the abdominal cavity, some of them, as the
spleen, can be drawn from their place in hernias.

Il. Alierations in the Organization.
?

Inflammation of the glands affects those rather with a
dense and compact texture, than the granulated ones ; yet
the breast is particularly disposed to it. Besides, it is
necessary to distinguish this inflammation from that of
the cellular texture and the neighbouring lymphatic
glands, this is important especially with regard to the
parotid, which is often thought to be inflamed, whilst its:
texture is sound and the cellular texture which surrounds
it is alone affected. This inflammation rarely terminates
in gangrene; on the contrary, suppuration and induration
are the frequent consequences of it. -

Some glands, placed on the exterior, when compre-
hended in wounds, become the base of a cellular cicatrix ;
but the glandular texture is not reproduced.

. The extreme frequeney of transformations of every
kind, in the system of which we are treating, has already
arrested the attention of Bichat. (Vol. 3d.) Yet it is still
necessary to establish a distinction in this respect ; in
fact, 1st, most of these transformations have been obsery-
ed in the liver, the kidney, the testicle and the mamma,
whether they are formed of textures analogous to those
which exist in a natural state, or whether textures wholly
foreign to the economy, except in a state of disease, con-

GLANDULAR SYSTEM. 255

stitute them; 2d, who does not know, on the contrary,
how rare they are in the lachrymal and salivary glands,
and even, to a certain extent, in the pancreas?

TL Alterations in the Development.

Notwithstanding the numerous irregularities in the
forms of the glands, we must not however take literally
-what has been said (Vol. 3d.) of the frequency of these
irregularities, compared with their rareness in the organs
of animal life. The difference is by no means so striking
as Bichat has pretended ; we have seen elsewhere that
the brain has not always precisely the same conformation
in its two hemispheres, and that Bichat was himself a
proof of it; his cranium exhibited in fact this singularity,
that the forehead was much more prominent on the right
than on the left, and that an opposite arrangement exist-
ed at the occiput, whence there resulted an inequality of
size, at the right andthe left, in the anterior and pos-
terior lobes of the brain. The bones, muscles and nerves
exhibit analogous yarieties. On the other hand, the
glands are by no means so variable that this would fur-
nish a character sufficient to distinguish them from the
preceding organs. ‘Their varieties are often insignificant ;
as in a bone, a groove, a vascular foramen or a depression -
for a tendon have not always precisely the same position, .
extent and direction; so in a muscle, the length of the
fleshy fibres, the extent of the tendon, the situation and
number of the intersections, &c. vary ad infinitum, and it
is of but little consequence in a gland, whether a lobe be
a little larger, an edge more or less hollowed out, an ex-
tremity more or less extended, &c. |

Besides, the glandular forms are more or less constant
according to the organs in which they .are examined.

256 ADDITIONS TO THE GLANDULAR SYSTEM.

The kidney alone exhibits almost as many varieties as all
the other glands together ; sometimes by itself or united
to that of the opposite side, sometimes divided as in
the foetus into many lobes, sometimes situated in the pel-
vis or in front of the vertebral column, there are but few
subjects in which it is perfectly similar. The liver, the
salivary and lachrymal glands, &c. exhibit less of these
differences.

The glandular texture is never preternaturally pro-
duced.

‘ ADDITIONS

TO THE

DERMOID SYSTEM.

Colouring Matter.—Mucous Body.—Papillez.

Page 273.—“ It is necessary to distinguish two por-
tions in the capillary system exterior to the chorion.
Ist. One is constantly filled with the colouring substance
of the skin. 2d. The second is constantly pervaded by
many fluids. These two portions are entirely indepen-
dent, and have probably no kind of communication.”

The colouring matter of the skin forms, in the negro, a
layer distinct, not only from the chorion and the epidermis,
in which Riolan thought it placed, but also from the other
parts of the mucous body, with which Malpighi con-
founded it. This matter exists also, though less apparent,
in the whites who, without it, would not differ from

33

258 ADDITIONS TO THE

albinos, who are entirely destitute of it. The mucous
body, which Malpighi regarded as a mere coat, a sort
of varnish covering the papille, a varnish for which Bi-
chat has substituted a reticular body, essentially formed
of vessels, and divided into two portions independent of
each other, appears in fact to contain many distinct parts
observed in the skin of the negro by M. Gaultier, and in

_ that of quadrupeds by M. Dutrochet.

Cae

Tf the skin of the heel of a negro be cut, a little
obliquely as to the substance and transversely to the

~-» direction of the lines which the papill represent, there 1s
. distinguished upon the divided edge the following objects ;

_ Ist, immediately above the papilla, and making a part of

them, there is found ‘a series of small vascular fasciculi,
designated by M. Gaultier by the name of sanguineous
bunches. 2d. Between these bunches and the epider-
mis, is seen a black undulating line, placed between two
white lines, one of which separates it from the first layer,
and forms the deep-seated, whitish layer, composed,
according to M. Gaultier, of white vessels. 3d. The

_ black line which is above, or the coloured layer, takes

the name of gemmu/e, on account of its undulations,
which make it appear as if composed of an infinity of
small concave bodies embracing the summit of the papil-
lx; each of these small bodies receives two sanguineous
bunches, the summit of the papille being bifurcated, as
we shall say hereafter. 4th. Finally, immediately below
the epidermis is the second colourless layer, or the suwper-
ficial whitish layer, formed of serous vessels like the
first.

There are then, according to this, four parts in the
mucous body, and by adding the two white layers to the
two portions admitted by Bichat, and which might then
be regarded as real insulated layers, we should have the

DERMOID SYSTEM. 259

true structure of this body. But among these layers,
the first, formed by the sanguineous bunches, does not
really belong to the mucous body; it is nothing else than
the termination of the vessels ramified in the papille,
and forms a part of what was formerly called the pepit-
lary body ; so that the number of layers which consti-. —
tute the mucous hody may be reduced to three; this is —
what M. Dutrochet has done in the analysis he has given
of the structure of the skin of quadrupeds. He has re-
cognized the existence of these layers, such as M. Gaul-

tier has described them ; only he has designated them in ae

the following manner; the skin is composed according to

“him, Ist, of the dermis; 2d, of the papille; 3d, of the
epidermoid membrane of the papillae, which is the deep-
seated whitish layer of M. Gaultier; 4th, of a coloured
layer; 5th, of a horny layer, which answers to the super-
Jicial whitish layer ; 6th, of epidermis.

The existence of a mucous body between the dermis
and epidermis, composed of at least three layers super-
added to each other, seems to be demonstrated by the
results which we have just stated; yet all anatomists do
not admit this existence. According to M. Chaussier,
the skin has but two distinct parts, the dermis and the
epidermis ; the one containing all the organic elements
of this membrane, without the possibility of establishing
the boundary between these elements, the other being the
inorganic or non-vital portion of it. Haller, Camper,
Blumenbach, &c. were inclined to reject the mucous body
in the skin of the white, and to admit its existence only
in that of the negro. 7

When the epidermis is removed by maceration from a
portion of very black skin, from that of the scrotum of
the negro, for example, the colouring matter remains in
part upon the dermis and in part upon .the epidermis,

260 ADDITIONS TO THE

more however upon the latter; but if the maceration be
continued, this matter is detached from both, and depo-
sited at the bottom of the vessel, where it can be collected ;
it has great analogy with the colouring matter of the
_ blood. This matter does not appear to be formed in the
coloured layer or gemmules in which it has its seat;
the papillze are the secretory organs of it, as well as of
this layer itself. When we produce by a blister the sepa-
ration of the epidermis and of the three subjacent layers
from the mucous body, the denuded dermis, at first red
and deprived of its colouring matter, afterwards takes it
again; when the blister is dry this matter is reproduced
in the form of little black points which gradually enlarge
and are finally confounded together, so that the cicatrix
is black though the mucous body may have been removed.
M. Gaultier attributes principally to the hairs the func-
tion of secreting this matter, because it is more abundant
where the hairs exist, and on account of the form it as-
sumes in the case of which we have just spoken ; but
since it is met with in all parts of the skin, jt is not
probable that its source is different according to the place
it occupies.

Besides, the colouring matter of the skin is by no
means stagnant in the mucous body ; the modifications,
which it experiences under many circumstances, show
that itis incessantly brought there and again taken up by
vessels, and consequently subjected to a real circulation.
Thus various authors cite examples of changes, almost
instantaneous, taking place in the colour of the skin, of
women becoming black during pregnancy, of men who
have experienced the same change from age or extreme
erief; thus negroes whiten more or less in diseases, old
age, &c. At birth, the negro is not coloured ; his skin,
similar to that of the white, is red like it, and only

DERMOID SYSTEM. 2

slightly yellowish. It is not till after birth that a brown
circle surrounds the nails, eyes, nipples and genital parts ;
on the third day these parts alone are black; the rest of
the body is yet only tawny. On the seventh, the colour
is general though pale, and continues so during child-
hood ; its intensity increases gradually in the adult age,
without acquiring however the same shade everywhere ;
- the parts that are first coloured remain generally the dark~
est. These successive changes which are also observed
in the other races, are so many evident proofs of the
motion of which the colouring matter is the seat.

This matter has the greatest relation with that which
colours the hairs, the iris and the choroid coat; thus all
these parts undergo the same change as the skin when it
is deprived of its colour, as is seen in albinos, from a de-
fect of organization.

The two other parts of the mucous body, viz. the
horny layer and the epidermoid membrane of the papille,
or the two whitish layers are not so well known as the
coloured layer. These layers besides being apparent in
the negro, are seen under many circumstances. Thus
the bulbs of the hairs exhibit on the interior, species of
flakes which appear to be formed by the epidermis of
the papille; when the nail is separated from the papille
which are below it, as may happen from a blow, these
papille are covered with a concrete matter which is
nothing else than this epidermoid layer. The horny
layer, by its extraordinary development, produces all
those horny productions which appear on the skin, either
in a natural state, as the horns of animals, the scales of
fishes and serpents, the nails, &c. or in the state of dis-
ease, as the horny substances which sometimes arise on
the skin of man ; these productions, all situated below
the epidermis, evidently belong to the layer of which we
are speaking. |

262 . ADDITIONS TO THE

The sanguineous bunches, as we have seen, are con-
founded with the papille ; these make a part of the der-
mis or chorion, whose external face they occupy, and
ought not to be distinguished from them, as has been
done, under the name of papiliary body. ‘Their arrange-
ment is remarkable ; the ruge which they represent form
regular lines separated by very evident furrows, and, in
addition, another furrow, not so deep as the first, but
having the same direction, divides each of these lines
near its summit into two secondary eleyations, so that
when the skin “is cut across perpendicularly to the direc-
tion -of these lines, the species of curved thread which is
seen along the divided edge exhibits undulations alter-
nately large and small; it follows from this arrangement
that each prominent line, simple at its base, seems to be
composed at its summit of a double row of papille.

The structure of these ruge of the dermis is almost
wholly vascular ; their analogy with the papille of the
tongue and the phenomena that are observed in them
seem to prove that the nerves are very numerous, and
that there isa peculiar venous arrangement, analogous. to
that of the erectile textures. It is to this very evident
arrangement, as well as to the nervous structure, that the
papille of the tongue owe the kind of erection of which
they appear to be susceptible. This erection is evident
in the tongue. The papillze of this organ are soft, flat-
tened and indistinct at the period of digestion, but
straighten up and become more apparent during masti-
cation. Something similar is seen on the skin of the
fingers; the pulp of this part often acquires in the exer-
cise of touch, a peculiar firmness, tension, and at the
same time redness.

It is in the papille, that most of the phenomena of
vitality, of which the skin is the seat, take place; it is

;
i

DERMOID SYSTEM. 263

there that the feeling and touch are exercised; it is
there that all the parts which are more superficially situ-
ated are secreted, there the colouring matter is formed,
there the hairs, nails, feathers, horns, scales, &e. are
produced. We cannot be astonished then at the quan-
tity of vessels which terminate there ; the whole capil-
lary system of the skin is brought there by the nature
of the functions which they perform. This idea how-
ever should not be exaggerated, and it must not be
thought that there are vessels nowhere else, that the
texture of the chorion more deeply situated is destitute
of them, and that all go to its surface; the dermis is
often injected in its whole thickness, both from inflam-
mation and fine injections ; only the surface seems to be
more so. By taking from a portion of injected skin,
rendered transparent by immersion in the oil of turpen-
tine, a thin strip, cut in the direction of the thickness
of the membrane, and by examining it against the light,
we do not see in it more vessels on the external than the
internal side. Finally, if all the vessels of the dermis
were contained in a superficial layer, we might, by
scraping the external surface of a portion of injected —
skin, destroy these vessels, and remove from the dermis
almost all its red colour; now, this cannot be done:

Cutaneous Absorption.

Page 298.—“ Many modern philosophers have. pro-
duced numerous negative facts against cutaneous absorp-
tion.”?

This absorption is much less marked-than that of the
mucous membranes ; it is not in fact evident unless there
is friction or excitement of the skin, by which the epi-

264 ADDITIONS TO THE

dermis is opened, raised up, or in part detached, and it
does not appear to take place from mere contact; at
least there are’ more facts against than in favour of this
last mode of absorption. Bichat explains these facts
which are apparently in contradiction to those in which
the absorption is evident, by the varieties of sensibility
which the skin exhibits; but he has not made the dis-
tinction which we have just established, and it is easy to
observe that it is when the skin is only in mere contact
with the substance subjected to its absorption, that this
is the most doubtful. Thus water applied on’ the sur-
face of the integuments most usually is not absorbed, as
Bichat had already remarked, and Symson, who pretends
that he has seen a foot-bath sensibly diminished after it
had been used by a patient, has been contradicted by all
those who have since repeated the experiment. That of
Mascagni, in which the inguinal glands are swelled under
the same circumstances, is but an insulated fact, and one
which besides may not be owing to the absorption of the
liquid. It is indeed said, that by holding one hand im-
mersed in a vessel of mercury, and by having in the
other a piece of any metal that is susceptible of being
attacked by it, as gold or silver, the latter blackens, pre-
cisely as if it were in direct contact with the mereury ;
whence it has been inferred, that the mercury was ab-
sorbed on one side and then carried into the blood, which
afterwards transmitted it to the opposite side ; but is the
fact certain, and have all these circumstances of it been
observed ? Some experiments, made with the greatest
accuracy by Dr. Rousseau of Philadelphia, prove on the
contrary, that the essential oil of turpentine, the absorp-
tion of which is so rapid by the mucous surfaces, as we
know, does not produce in the urine that characteristic
odour, the unequivocal indieation of its absorption, when

DERMOID SYSTEM. “265

it is merely applied upon the skin, taking care not to
allow it to be introduced by respiration. Before we
admit this absorption, let us wait till new experiments
have demonstrated the ssi of the absorption by sim-
ple contact. :

As to the irregularity which Bichat attributes also to
the other species of absorption, founded upon this, that
the insertion of vitus is not always followed with success,
it is possible in fact that the viru’ may not be absorbed in
this case; but we should be careful not to confound its
passage into the blood with its apparent effect, especially
when this effect is purely local, the first might very
well take place, and the other not exist.

The same remark is applicable to what most authors
say respecting the greater facility of absorption during
sleep, hunger, &c. and in general in all the states which
dispose to weakness. Contagious and other miasmata
are perhaps more active under these circumstances only
from the greater susceptibility of the organs.

Some authors have spoken of a gaseous absorption
which is constantly taking place upon the integuments,
and the result of which they have endeavoured to esti-
mate; according to others, the skin is the seat of an exha-
lation of the same nature. It is evident that if these twa
functions exist there, their effect must be confounded,
and that it is impossible, by collecting the gases, the
atmospheric air, for example, which may have remained
on the surface of the skin, to distinguish ‘if the changes
of proportion that are observed in them are owing to a
diminution of some of their principles or to an increase
of the contrary ones, and consequently to determine
what belongs to exhalation and what to absorption. It is
then incorrect to say, as Fourcroy has done, that the
skin gives out azote; the nature of this exhalation, if it

34

266 ADDITIONS TO THE

takes place, is very difficult to be determined. Besides,
the proof which Fourcroy has given of its existence,
drawn from the bubbles that are disengaged from the
surface of the body when it is immersed in a bath, does
not appear to me to be substantial. These bubbles are
nothing but the air which adheres to the integuments and
which has become rarefied by the heat of the bath; when
all this air has once escaped, the disengagement ceases ;
these bubbles are not séen to form in the cold bath, the
air not having there, from the want of dilatation, the same
tendency to quit the surface of the skin.

- Sebaceous Glands.

Page 307.—** There is I think as much probability in
the supposition of the exhalation, as of that of the secre-
tion of the cutaneous oil.”

The existence of the sebaceous glands or follicles of
the skin is proved by the following considerations, which
have been already in part stated in the article upon the
mucous glands. |

Ist. These glands are apparent in many places, as on
the nose, the forehead, the hairy scalp, around the lips,
in the hollow of the axilla, in the groin, in the neighbour-
hood of the nipples and arms, and in general wherever the
‘cutaneous oil is secreted in great quantity. M. Gaultier
asserts that the bulbs of the hairs are surrounded, at
their orifice, by nine sebaceous follicles destined to
furnish the oily matter which lubricates them.

2d. These glands are very variable in their size, and
there are subjects in whom they do not seem to exist in
certain parts, in which they are found very large in
others ; so that by thus collecting together all the insulat-

DERMOID SYSTEM. 267

ed observations, there is perhaps no part of the skin in
which they may not have been met with,

3d. They often appear suddenly where they were not
before distinct, and even acquire so great a size as to
constitute a real disease. It is not probable that, in this
case, these glands are formed all at once ; their arrange-
ment is too similar to what they exhibit in the places
where they are naturally observed.

4th. The same substance everywhere covers the sur-
face of the skin; the organs which furnish it must then
be generally distributed. Now the sebaceous follicles
are evidently these organs, in the Asatte where they dis-
tinctly exist.

It may then be accurately deduced from all this, that
the sebaceous glands exist everywhere, and that their
tenuity alone often prevents them from being perceived ;
that consequently the oily fluid of the skin is, as is gen-
erally thought; the product of a secretion.

The structure of these glands is analogous to that of
the mucous glands, which we have described ; the skin
folded upon itself appears in general to constitute them.
The membrane which forms them is continued with the
dermis ; the epidermis is very apparent in the tumours
which result from their dilatation ; these tumours, when
cut open and emptied of the matter they contain, are
evidently covered on the interior by an epidermis, which
is detached from them by maceration with that of the
neighbouring skin. The horny layer itself is indicated
in these follicles by the productions of that kind which
are sometimes developed in them; in fact, hairs have
been seen to derive their origin from them, and horns
to arise in them and push out through their orifices ; the
coloured layer is also evident in them under some cir-
cumstances.

268 ADDITIONS TO THE

MORBID ANATOMY OF THE DERMOID SYSTEM.

I. 4lterations in the External Forms.

The skin when distended experiences various changes.
(Vide Vol. 3d. Properties of Texture of the Dermoid
System.) When it is so for a long time, the fibres of
the dermis are not only separated, but. they are broken
in various places ; hence the whitish striz of the skin of
the abdomen of women who. have been once or many
times pregnant; these striz, often important im legal
medicine, because they are constant, are real. cicatrices.
When the distension has been many times repeated or
earried very far, the skin having lost in part its tendency
to contract, becomes larger than is. necessary to cover
the subjacent parts, and remains .loose and soft, or forms
folds, as is seen on the skin of the abdomen; it is the
same phenomenon as that which produces the wrinkles
in old people who become emaciated, as has been said
elsewhere. Besides, the skin varies in this respect in
different individuals; one woman, after the first preg-
nancy, has the abdominal parietes more loose than those
of another, whose abdominal parietes remain smooth and
uniform, though she may have had many children. Age
has also much influence upon it. The same differences
exist in diseases, when a tumour, for example, has vio-.
lently separated the skin of the neighbouring textures ;
hence the modifications to be observed with regard. to
the quantity of the skin to be left, when these tumours
are removed, according to the age, Sex, casindeaiiaiuade
size, duration of the tumour, &c.

DERMOID SYSTEM. 269

The surface of the skin is deformed by many produc-
tions of a very different nature. Some are the evident
product of inflammation ; they will be noticed hereafter.
The others constitute peculiar degenerations, and will
also be presently examined. But there are some which
seem to depend only on.a preternatural increase of some
one of the layers of which the skin is composed. Thus
the horny layer is raised up upon the integuments in the
form of hard excrescences, in every respect similar to
horns; the vascular net-work of the papille raises the
delicate epidermis, and produces exuberances more or
less red, such as the growths from syphilis; the substance
of the dermis itself grows and is produced on the surface
and forms warts.

‘The horny productions, respecting which there are
many observations in existence, do not depend simply
on the cause that we have just pointed out ; they may be
divided into three kinds. 1st. In consequence of wounds
and ulcers, there is often formed upon the cicatrices
productions of this nature. 2d. The sebaceous follicles
are also sometimes the origin of these horns, of which Sir
Astley Cooper and Sir Everard Home have given exam-
ples; they have then concentric layers such as are seen
in trees. 3d. Finally, there are horns which arise irregu-
larly upon all parts of the skin, and which cannot be
referred to either of the two preceding species ; these
are those especially which seem to have their seat in the
horny layer of the skin, and to be nothing else than
amore copious secretion of this layer, from the irrita-
tion of the subjacent papillae. Corns on the feet are
from a very similar source; they are formed by a small
hard round body, arising from the horny substance of
the skin, and covered by the laminz of the epidermis ;
enly this species of horny matter is foreed by pressure

270 ADDITIONS TO THE

into the substance of the dermis, and sometimes ever
below it, instead of growing on its surface.

The enlargement.of the sebaceous follicles of the es
produces a peculiar. kind of tumours. When this en-
largement is inconsiderable, the tumour, hardly percepti-
ble, is discoverable on the surface of the skin only by a
black point, from which can be pressed out the sebaceous
matter contained in it, and taking the form of the aper-
ture of the follicle, escapes under the form of a small
worm, and has even been sometimes taken, on_ this
account, for the larva of an insect; this black point is
owing to the particles which float in the air and which
soil the entrance of the follicle, When the matter is
accumulated in greater quantity, the tumour is more
prominent, and constitutes, according as the. orifice of
the follicle is open or not, those pimples, so common
on the face, on the skin of the nose especially, or the sub-
cutaneous wens that are seen in the various parts of the
body. These never depend on any other cause; all
those pretended meliceris, atheromas and steatomas,
which are developed on the head, under the hairy scalp,
in the sub-cutaneous cellular texture of the extremities,
thorax and abdomen, and which differ only in the degree
of consistence of the matter which they contain, as their
names imply, are at first situated in the substance of the
skin, as is easily proved by examining them in their
commencement. ‘There may be often observed .in the
same subject the kind of gradation which these tumours
follow in their progress, that is when there are many of
them ; the smallest then exhibit an opening very appa-
rent on the surface of the skin, whilst the others remove
by degrees from the integuments, to which they are still
however attached, in the greatest number of cases, by a
hollow filament, which is the neck of the follicle elon-

rd

DERMOID SYSTEM. 271

gated by distension. There are no true wens but the
fatty tumours. Thus the substance of those called en-
cysted perfectly resembles the sebaceous matter of the
follicles ; this kind of tumours have, like the latter,
an internal epidermis. These last characters would
almost alone be sufficient to establish the identity of
these tumours with the follicles, if their connexion with
the skin in the beginning could not be demonstrated.
The opening of the follicles, instead of being obliterated,
is sometimes so enlarged, in those small tumours of the
skin before noticed, that the bottom of them is almost
completely exposed; their internal surface, in contact
with the air, then becomes dry, the tumour ceases to
grow, and there remains simply in the place it occupied,
a kind of cul-de-sac, continuous with the skin, which
appears to be there folded up. This arrangement renders
the structure of the follicles very evident.

The whole ‘cutaneous system is the seat of a kind of
atrophy, in the marasmus, which succeeds slow diseases ;
in this case the colouring matter disappears, the dermis
dries and is thinner, the papille are diminished and the
skin becomes rough from the prominence of the bulbs
of the hairs which are below it. Opposed to this state
is the superabundance of life so common in the integu-
ments of the face, especially in drunkards, and which
is shown by the vascular bunches in this part. A long
continued irritation may also thicken the dermis, as is
often seen around old ulcers.

Il. Alterations in the Organization,
Cutaneous phlegmasias form a numerous class in patho-

logy ; but their infinite shades are confounded in great
measure in the eyes of the anatomist. The alterations

272 ADDITIONS TO THE

of texture which they produce in the skin are always
nearly the same, however numerous may be the eruptions
with which they cover it. The common characters of
most of the exanthemata, both acute and chronic are an
increase of blood in the capillary net-work, and conse-
quently a greater development of this net-work, either
generally, or in points more or less precisely insulated ;
a fluid differing from the blood raising up the epidermis
or spread on its surface and forming there various kinds
of scabs ; the epidermis itself in various ways altered and
its regular production often prevented. These affections
do not essentially differ except in the degree of excite-
ament which preduces them, the different structure of the
skin in’ the parts which they occupy, and the peculiar:
habit of the persons who are affected with them; all
these circumstances produce modifications in their pro-
ducts. Perhaps however this subject deserves new re-
searches; since the seat of these diseases in the cutaneous
texture does not appear to be always the same}; since
tinea, for example, seems to arise more especially from
the sebaceous follicles, and some eruptions appear to be
confined to the most superficial layers of the skin, whilst
in others the whole substance of this membrane is altered.
In general, all those who have written upon the diseases
of the skin are more engaged in describing minutely the
forms they affect upon this membrane, than in investi-
gating the changes they produce in its organization.
Besides, the usual effects of inflammation have been
observed in the skin. It suppurates, not only when its
epidermis is removed, as from a blister, but even when
its texture is sound, in the same way as the cellular tex-
ture ; the pus is usually in small cavities which raise up
the epidermis, as is seen in the pustules of the small pox.
Uleeration is frequent in this membrane, less so however

sf
;
‘

DERMOID SYSTEM. 2738

than in the mucous system ; it is sometimes connected
with suppuration, as is commonly observed in the small
pox; at other times it is the effect of a peculiar cause,
such as syphilis.. It is necessary, moreover, to distin-
guish those cases in which ulceration proceeds from
without inwards, from those in which the skin is dis-
tended, at first only becomes thinner and is finally in-
flamed and. destroyed, from within outwards, as takes
place in abscesses, aneurisms, &c.

Simple wounds of the skin heal quickly, and without
the formation of fleshy granulations. A. plastic layer,
analogous to that which is. formed between the other
divided textures, and which M. .Brachet has found to be
composed of gelatine and albumen, reunites at first weakly
the edges of the wound, which can in the beginning be
separated afresh, without giving hardly any pain, or
occasioning the flow of blood, with which this layer is
not yet penetrated. Vessels are afterwards produced in
this substance, which at the same time acquires more
consistence, and the cicatrix is complete. This cicatrix is
soon confounded with the texture of the skin, from which
it finally cannot be distinguished.

The phenomena are also very simple when the skin is
destroyed only in its superficial layers, and the dermis is
merely denuded; the epidermis is then reproduced with
great rapidity over the whole extent of the wound ; this
is what is seen in blisters, burns of the second degree,
slight excoriations, &c. If however thei rritation is great,
as in a burn, suppuration comes on, and the cure is not
so speedy ; but fleshy granulations are not formed unless
the suppuration is long continued, as in blisters.

On the contrary, these granulations exist necessarily
when there is a complete loss of substance of the skin,
and the lips of the wound remain separate; they always

35

274 ADDITIONS TO THE

precede in this case the formation of the cicatrix, which
then arises from the various textures laid bare, particu-
larly from the cellular.

The skin is but little subject to organic transforma-
tions. It acquires under some circumstances all the char-
acters of the mucous membranes; this takes place, when
it is long in contact with itself and deprived for a length
of time of the air on its exterior; a less thickness of the
dermis, a greater redness of its surface, which continually
pours out a copious mucous fluid, and an extreme delicacy
of the epidermis, covered with very distinct villi, are
observed in this case, an example of which is cited by
Hébréard in which this alteration was produced in the
hollow of the ham, in a paralytic patient, by the constant
flexion of the leg upon the thigh. We have seen, in the
Cartilaginous System, that the skin sometimes experiences
the cartilaginous transformation.

The cancer of the skin assumes a peculiar form anil
is only observed in this membrane and in the mucous
system; it constitutes most often ulcerations around
which the neighbouring texture is little altered, so that
in an anatomical view, there is no resemblance between
these ulcers called carcinomatous and the other cancer-
ous affections. There arises also upon the integuments,
in some cases, excrescences analogous to the cancerous
polypi of the mucous membranes. In the sub-cutaneous
cancerous tumours, the skin is subsequently affected in
two different ways; sometimes it contracts a very great
consistence, a remarkable kind of hardness at the same
time that it adheres intimately to the parts which it
covers ; sometimes it ulcerates from within outwards, as
takes place in the ordinary termination of cancer.

j

DERMOID SYSTEM. 278

Ill. Alterations in the Development.

The defects of conformation of the Dermoid System,
are, Ist, absence of the skin to a certain extent, where
it usually is found, which is scarcely ever seen unless
there is at the same. time a want of the subjacent parts,
as when the cavities of the mucous membranes exhibit
preternatural openings; 2d, various elongations which the
texture of the skin forms, and with which the surface
of this membrane is covered; 3d, the spots from birth
or nxvi materni ; these are sometimes merely an altera-
tion of the colouring matter, sometimes an affection of
the vascular net-work, and most often become in the
latter case after birth, tumours that are called varicose,
and which have much analogy with the erectile textures.
The spots are often covered with hairs,

New integuments are preternaturally produced when-
_ ever the parts naturally covered by the skin are deprived
of this common covering, as after wounds, ulcers, ab-
scesses, gangrene, &c. ; the new texture which is formed
under these circumstances constitutes the cicatriz. I
would observe, upon this subject, that this word serves to
designate all the modes of union which take place be-
tween divided parts; now there is a number of these
modes, and consequently. several species of cicatrices.
ist. There are those which succeed the internal ruptures
which various organs experience, the skin which covers
them remaining sound; those of the different systems
have been examined under each one of them in particu-
lar ; we have seen that they partake in general more or
less of the textures in which they are situated, though an
analogous cause, an exudation of a substance capable of

276 ADDITIONS TO THE

concretion, most often presides over their formation in
the beginning. There are no fleshy granulations when
these cicatrices are completed. 2d. The union of wounds
by the first intention furnishes a second kind of cica-
trices, which has great resemblance to the preceding, and
which only differ from them in this, that the divided tex-
tures communicate at first on the exterior, a circumstance
which their mutual contact soon renders nothing, so that
this case is then the same as the first. The skin and the
cellular texture perform the greatest part in this union,
which is effected, like the preceding, without the pro-
duction of fleshy granulations. 3d. Finally, cicatrization
properly so called is the mode of cure of wounds, and,
in general, of all solutions of coritinuity that are apparent
‘on the exterior, whose neighbouring edges remain sepa-
rate, whether because they have suffered too great a loss
of substance, or because the effects of contractility of tex-
ture have not been prevented, or because the structure of
these edges renders their approximation impossible, as in
wounds of the bones. ‘There is in this case, the only one
which we should notice here, suppuration, formation of
fleshy granulations, and consequently of a membrane
analogous to the skin. This membrane is everywhere
the same, whatever may be the denuded texture, as is
proved by the homogeneous cicatrices which succeed
amputations, wounds of the cranium and the thorax, in
which parts of a very different nature are concerned; the
cartilages are the only organs which do not contribute
to its formation.

Two periods may be distinguished in the cicatrization
of a wound; Ist, the wound is covered with fleshy granu-
lations ; 2d, an epidermis is formed upon these granula-
tions, to give origin to the cicatrix. It would be easy to
‘show that there is a greater number of these; but these

f

DERMOID SYSTEM. 2717

are sufficient to give an idea of the mechanism of the
production of the cicatrices. ‘These periods are described
in Bichat, Vol. 1st. We shall now pass them rapidly
in review.

First Period. 'The small bodies so improperly called
fleshy bunches, and which have also been known by the
name of carunciles, granulations and cellular and vas-
cular bunches, arise in proportion as suppuration is
established, but with a different rapidity in the different
textures ; In an amputation, for example, they are de-
veloped in the first place upon the cellular texture which
occupies the interstices-of the other parts, in the second
place on the surface of the divided muscles, soon after on
the fibrous organs, and still later in the bones, most often
in these last not until a delicate lamina is detached from
them ; in general they are produced so much the quicker
as the textures are more cellular and vascular. ‘The size
of these bunches varies; their arrangement is so much
the more regular in proportion as they are smaller, and
the cicatrization of them is also quicker. ‘The membrane
which they form by their union has below it a compact
cellular texture, appearing as if penetrated with concrete
albuminous fluids. This membrane contains blood ves-
sels, for the bunches bleed from the least touch, and red-
den or become pale from various causes. The absorbents
are not demonstrated in it, except by the absorption
which these bunches perform, and by the ulceration to
which these are so disposed, that often by a deviation in
regimen, they totally disappear in less than two hours
from the surface of a wound; their extreme sensibility
leads to the belief that there are nerves in it, though they
have never been seen. The membrane of the fleshy
bunches is endowed with a very evident. contractility,
which explains the real contraction and diminution of

278 ADDITIONS TO THE

wounds, which is so much the more evident as the skix
is at the same time more moveable and extensible. The
cellular nature of this membrane has been demonstrated
elsewhere ; many authors consider it, with Fabrus, as a
mere extension of the cellular texture; but the opinion
of Hunter, which has been more fully explained by Home,
is more probable. This opinion, which I have given in
the Additions to the Cellular and Capillary Systems, con-
sists in considering it, not as a preexisting cellular tex-
ture, but as a new production, not being able to be formed
except where there are cellular texture and blood vessels,
and exhibiting in its development phenomena analogous
to those of the natural development of the organs.

Second Period. When the fleshy bunches have re-
tracted as much as the resistance of the integuments in
the neighbourhood of the wound will allow, they are cov-
ered with epidermis, which constitutes the second period
of cicatrization, the formation of the cicatrix. The new
epidermis begins to be formed at the circumference of the
wound, where it is evidently continued with the neigh-
bouring epidermis, and afterwards advances by degrees
towards its centre ; sometimes, as in large ulcers of long
standing, it is produced at the same.time in small parti-
cles.in the middle, and the various points afterwards
unite together ; the pus ceases to be secreted in propor-
tion as the epidermis is formed. ‘The cicatrix is com-
plete when the whole extent of the wound is covered
with epidermis. This cicatrix, delicate at first, soft, red-
dish on account of the want of thickness of the epidermis
which covers it, more adherent and less solid than the
skin, finally becomes completely analogous to this mem-
brane. The cellular texture which is below it regains by
degrees all its extensibility, unless the cicatrix rest upon
a bone; in this case it remains adherent.

DERMOID SYSTEM. - 279

The new cutaneous texture when perfectly developed,
exhibits the following characters. Ist. This texture is
more dense than that of the skin and has a greater resem-
blance to the fibrous textures ; fewer blood vessels enter
it, hence the white colour of the cicatrices and the rare-
ness of their preternatural redness. 2d. The dermis,
which is met with in it, has less evident areolz, and less
distinct fibres and laminz than that of the skin ; this der-
mis is in general destitute of papilla, as the smooth and
shining appearance of its surface indicates. 3d. The
epidermis is. very apparent in cicatrices, and is confound-
ed with that of the surrounding skin. 4th. Camper has
denied the existence of the mucous body in it; but this
body is demonstrated there, in negroes, by the colour
of which their cicatrices are the seat. This colour exists
in almost all cases ; only a sufficient length of time is re-
quired for it to be developed, and the tint it assumes is
almost always paler than that of the integuments; how-
ever in some rare cases, this tint has been seen of a
deeper colour. The horns which arise upon the cicatrices
indicate in them the presence of the horny layer. 5th.
The texture of the cicatrix is more disposed to ulcerate
than the skin properly so called ; ulcers which affect at
the same time these two membranes make much more
rapid progress in the first than in the second.

af f t

. ADDITIONS
To THE

EPIDERMOID SYSTEM.

Means of union of the Epidermis with the Dermis.—
Ezxhalant and Absorbent Pores.

Page 351.—* By separating the epidermis by macera-
tion, which is the most proper means, we see on its in-
ternal surface many small elongations of greater or less
length, and which, when examined attentively, appear to
be nothing but the broken extremities of exhalants and
absorbents. In fact these little elongations . . . have all
of them an oblique course, and terminate in the pores
which, we have said, pass through the epidermis to go to
its surface.”

The nature of the elongations which are intermediate
between the dermis and the epidermis, and which can
only be seen by separating these two parts from each

36

382. ADDITIONS TO THE

other, is not easily ascertained. Kaaw Boerhaave and
W. Hunter maintained, which is nearly the opinion of
Bichat, that they were the vessels of the sweat or the
cutaneous transpiration. But injections do not reach
these elongations ; inflammation, which renders the whole
skin vascular, does not colour them sensibly. Cruik-
shank considers these filaments as epidermoid substance
which has dipped down into the areole of the dermis.
But do these elongations really exist when the epidermis
is adherent to the dermis? Nothing proves it. They
should rather be considered as species of mucous tracts
which are formed by the separation of the substance
intermediate to the dermis and the epidermis, rendered
fluid and viscid by putrefaction or stewing to which the
skin is subjected for the purpose of separating the epi-
dermis.

The existence of the pores themselves, such at least as
are usually represented is far from being accurately demon-
strated. Physiological considerations, and even the injec-
tions of Haase would lead to the belief that the openings
of the vessels go to the last layers of the skin, that is to
say, to the epidermis; but microscopical. examination,
which is more worthy of confidence than physiological
conjectures, does not detect pores in the epidermis. By
examining against the light the epidermis of a portion of
skin from which the greater part of the hairs has been.
removed,.there is seen very distinctly transparent places
which have been regarded as openings. Leuwenhoeck
thought even that he discovered pores in the epidermis,
and he has given a drawing of them in his Arcana
Nature. But as this great observer used only simple
lenses, which magnify but about a hundred and sixty
times, he has perhaps mistaken for pores the foramina of
the hairs. Fontana, in his work upon the venom of the

EPIDERMOID SYSTEM. 283

viper, speaks of a texture composed of serpentine vessels
which he has seen by the aid of the microscope; but
M. de Humboldt, who has examined the human epidermis
with a microscope that magnifies 35,200 times, asserts
that the serpentine cylinders are folds and not vessels; in
some observations made upon the epidermis magnified
312,400 times, he was unable to discover pores in it.
I have closed the extremity of a tube with a piece of
epidermis, the tube containing a column of mercury: of
more than two feet, and not a particle of the metal passed
through the epidermis.

It must be concluded from these different observations
that there is on the surface of the skin a non-vyascular
barrier between organization and the atmosphere, and that
whether for entrance or for exit, substances must pene-
trate this barrier by a sort of imbibition, which would
approximate this extreme part of the organization, to the
most simple bodies of either organic kingdom, which are
destitute of vessels. In fact, as we have just said, there
are neither vessels, pores nor any opening discoverable
by the microscope, whether the oblique insertion of the
hairs conceals those which give passage to them, or
whether the epidermis furnishes a sheath for them which
exists after their removal and fills the foramina with which
it is pierced. We cannot however deny absolutely, the
existence of the pores from microscopical examination
alone ; for if we make a puncture in the epidermis with a
very fine needle, we cannot discover this opening by the
microscope, as Cruikshank has proved by experiment ;
the same thing takes place in a very delicate lamina of
gum elastic or caoutchouc, in which a very narrow open-
ing is made; on the contrary, the opening continues
when perfectly dry epidermis is employed; paper that
is used for filtrating presents the same difference accord-

284 ADDITIONS TO THE

ing as itis dry or moist. This point, which has been
much discussed by authors, does not appear to me to be
yet sufficiently clear. |

Epidermis of the Mucous Membranes.

Page 369.—‘¢ What is the place in which the epider-
mis terminates that lines the origin of the mucous sur-
faces, or if it exists everywhere, where does it begin to
become no longer apparent from the action of our dif-
ferent reagents? We cannot, I think, determine with
precision ; it diminishes in an insensible manner, and is
lost as it were by degrees.’

Bichat leaves here two questions unsettled ; the first is
to know if the deep-seated mucous surfaces have an
epidermis ; and the second is, at what place this epider-
mis ceases or changes its nature. The soft and pulpy
state of the deep-seated mucous membranes, the very
great resemblance which exists between the composition
of the mucus and that of the epidermis, and the presence
of villi where this is but little apparent, lead to the belief
that it is in fact wanting in deep-seated parts. On the
other hand, those who admit its existence there cite the
cases of inversion of the rectum, of the small intestines in
preternatural ani, of the uterus, &c.; in which a distinct
epidermis covers the whole of these parts; they rely also
upon the membranous excretions, which, according to
them, have no other source. These reasons are by no
means decisive; there is no proof that the epidermis of
the preternatural ani, for example, exists originally, and
that it is not formed afterwards entirely by the contact of
the air. As to the membranes voided in phlegmasias of
the intestines, the bladder, &c. analogy should teach us

EPIDERMOID SYSTEM. 285

to regard them as false membranes of the same kind as
those which cover under the same circumstances the eye,
the mouth, the pharynx, &c. However it may be pos-
sible that a very delicate epidermis, the fineness of which
would render it still more difficult to be perceived, may
be found upon the deep-seated mucous surfaces ; this first
question can hardly be resolved otherwise than it has
been done by Bichat, who is much inclined to the nega-
tive.

The second leads to something more positive. In
many parts of the mucous system, there exists a very
evident line of demarcation between the portion of this
system placed near the exterior and that which is more
deeply situated. This line is owing to the epidermis of
the first, which ceases where the second begins. Boil
the mucous coat of the stomach and that of the oesopha-
gus, the epidermis, raised up upon the latter, will soon form
a bunch corresponding exactly with the cardiac orifice,
and beyond which this epidermis will cease to be appa-
rent. This is what has even led to the assertion that
there was at this place an interruption in the mucous sys-
tem, and that the mucous membrane of the stomach was
not a continuation of that of the oesophagus. But the
epidermis alone forms this limit; the rest of the mem-
brane is continued perfectly. This is so true, that in
animals, the line of demarcation does not always corres-
pond with the cardiac orifice, and often this line en-
croaches more or less upon the stomach, as is shown in
the plates of Home, in which it is seen to approach
nearer and nearer the pyloric orifice, according to the
species of animal. It is the same case with the mucous
membrane of the vagina in relation to that of the uterus ;
its epidermis terminates at the neck of this viscus, the
interior of which is not the less lined by a peculiar mu-

286 ADDITIONS TO THE

cous:‘membrane, differing from the first only in having
a less degree of thickness and fewer villi. The same ar-
rangement exists at the neck of the bladder, as is proved
by the experiment noticed above, made upon this viscus,
and the urethra which is inserted into it. This remark
applies in general to all the mucous ducts which open on
the exterior, and terminate in a membranous reservoir.

Nature of the Nails. :

Page 375.—‘* We cannot consider these’’ (the nails,)
‘ag mere layers of epidermis applied to each other.’’

Malpighi regarded the nails as the consequence of the
drying of the papille of the dermis. Ludwig said that
they arose from the dried nervous substance. The ex-
amination of the horny parts of animals shows that they.
are formed by a horny substance, of the same nature as
that which constitutes the hoofs, horns, scales, &c. of
various animals. The epidermis only covers these parts,
which all belong to the horny layer which is subjacent
to it; when it is wanting on their surface, it is because
friction has destroyed it, or that it is confounded with
their superficial laminz, as is seen particularly with
regard to the nails.
~ Considered in animals, these are of two species. Ist.
They are such as resemble those of man, these are the
small nails (ongwicules.) 2d. Others differ from them
in their arrangement have received the name of nails
(ongules); they include the hoofs of various quadrupeds.
We might add to them the horns, the origin of which
is precisely similar to that of the nails and the hoofs. It
is necessary however to distinguish among these the horns

EPIDERMOID SYSTEM. 287

of deer, and the horns properly so called, or those of
ruminating animals. The first are entirely osseous, and
raise up the skin, instead of being seated on the surface
of this membrane; the second alone belong to this sur-
face ; only they usually surmount osseous elongations, to
which they serve, as it were, for sheaths. The nails of
man are not coloured; those of animals and their horns
are so on the contrary quite often; their colouring matter
appears to reside in general, in the horny substance
itself. . |

The nails and the horns are formed by the same me-
chanism. When a horn is torn out of.an animal, the
-papillz in a high degree vascular, which have been laid
bare, pour out a fluid matter which can be seen at first
to rope between the fingers, if we may be allowed the
expression, and which afterwards thickens and hardens
by degrees; below this first layer, there is formed a
second which raises it, and then a third, and thus in suc-
cession, so that a new horn results from this successive
union of layers; this horn continues to grow from its
base in the same manner, the new layers constantly rais-
ing the old ones. Now the same thing is observed in
the hoofs, as also in the reproduction of the nails of man.
The form alone differs, because the parts secreting the
fluid are variously formed. When the nail is torn out,
the papillz, after having bled copiously, and appearing
bare though having still above them the deep-seated
whitish layer, are covered with a soft, white lamina, the
consistence of which gradually increases; then new
lamin are produced below, so much shorter as they are
more distant from the root, and give to the new nail the
thickness which it is to have; the ulterior growth de-
pends on this, that the horny substance is continually
poured out at the extremity of each of the lamine, which

288 ADDITIONS TO THE

occasions the whole of the nail to be pushed forward.
This mode of development may be compared to that
which takes place in the silk worm, the fluid of which
is constantly reproduced in proportion as it acquires. con-
sistence, and’ constantly pushes before it the fluid which
has preceded it. Thus the nail would grow indefinitely
if it were not habitually cut, or worn off by friction.

The longitudinal striz which the nails exhibit on their
surface are no indication of a fibrous structure; these
striz appear to depend on the arrangement of the sub-
jacent papille.

|

MORBID ANATOMY OF THE EPIDERMOID SYSTEM.

The parts comprised under this system haying no or-
ganization, properly speaking, are subject to but a small
number of alterations, which even are not inherent in
them, and depend only on the changes that are expe-
rienced by the vitality of the skin, their common support.
It is with these parts as with the different fluids that are
poured out upon the mucous, serous, synovial surfaces,
&c. and the alterations of which depend entirely on those
of the organs which furnish them.

The epidermis thickens, becomes thin, is raised up on
the surface of the dermis and destroyed by various causes,
the most of which have been already examined. It ase
sumes the form of vesicles, blisters, furfuraceous scales
and large plates, when it is raised up or almost entirely
detached. Its reproduction, usually easy, sometimes
becomes impossible from the great irritation of which the

EPIDERMOID SYSTEM. 289

skin is the seat, as in a burn or chronic pemphigus, and
then the patients suffer much, the mucous body being
bare: At other times, the skin, red and swelled, furnishes,
instead of the fluid which produces it, a scabby, crusty
matter, joined to a serous fluid which oozes out copiously,
as is seen in some species of herpes.

The excrescences of the nails are especially frequent
in the dry herpes, in which the skin assumes the appear-
ance that has been compared to the lichens of trees, in
which the epidermis is thickened and cracked in various

directions. They come upon the toes, from a cause an-

alogous to that which produces corns upon them. In
some cases, they appear to be owing to the progress of
age.

The nails become soft and brittle in individuals affect-
ed with scrophula and herpes. They exhibit also besides,
in some cases, a peculiar alteration which authors do not
appear to me to have described. It eonSists in a sort of
' chronic inflammation ‘of the skin which surrounds the
root of the nail; a brown circle, painful when pressed,
is formed at this place; the nail becomes at the same
time thin and like amembrane. Buzzi has given some
examples of this affection, which I have many times ob-
served in children, and sometimes in adults.

Thé very improper expression of the nail growing
into the flesh serves to designate a state in which the
skin surrounding the nail upon the edges or near its
extremity goes beyond it and advances more or less upon
the free face. There results from it pains more or less
acute by the pressure which the cutting edge of the nail
makes upon it. This inconvenience hardly ever happens
except to the great toe, in which the tightness of the
shoes often produces it. The extraction of the nail is
the most efficacious remedy for it.

37

‘

d, ADDITIONS
TO THE

PILOUS SYSTEM.

Structure of the Hairs.

Page 401.—‘ White hairs may experience vital phe-
nomena, of which, I believe, there are a few examples.
But all this is subordinate to the future experiments
which will elucidate the pilous structure more than it
now is.”

This structure exhibits some new peculiarities which
we shall state.

The bulb of the hairs, or the kind of canal from which
they derive their origin, is in fact a small sac lodged in
the substance of the skin or in the sub-cutaneous cellular
texture, and receiving the extremity of the hair which
is implanted in it. This bulb is not very evident in man,

292 ADDITIONS TO THE

but has been described by Chirac and Gaultier, from its
arrangement in the hairs of the whiskers of some animals,
its size in them rendering its structure more evident. It
appears to contain like the sebaceous follicles, the same
parts as the skin, and to be continued in the same way
with this membrane. A layer analogous to the dermis
is the base of it, and is evidently continued with the
dermis of the skin. Within this layer there is an elon-
gation of the mudous body, the continuity of which with
this body is seen very well in animals whose skin is
coloured ; this part is soft and more easily perceived than
the skin ; it is composed, as in the skin, of many layers.
The epidermoid layer is the inner one; it is less distinet
than the others, but it is found in feathers, which have
a great analogy with the hairs, and in the quills of quad-
rupeds, which are only hairs made very strong. A coni-
cal papilla, similar to the asperities of the dermis which
surmount the palm of the hands, the sole of the feet, &c.
fills the bottom of this kind of follicle.

The bulbs of the hairs receive vessels and nerves. The
nerves constitute in great part the elongations which go
to their external face, and which oceupy particularly their
extremity opposite to the skin, they form for them a sort
of pedicle. Many anatomists have traced these nerves
in animals ; in man even nervous filaments are seen to
penetrate the bulbs of the eyelashes and those of the
hairs situated at the opening of the nostrils.. The vessels
are also situated, according te some, in the substance of
the elongations attached to the bottom of the bulbs; but
M. Gaultier has seen them entering at the other extremity,
coming from the dermis of the skin, and enclosed between
the dermoid layer of the bulb and the mucous layer.

The neck of these small sacs is surrounded with seba-
eeous follicles, pouring out an oily matter, which covers

PILOUS SYSTEM. | 293

the surface of the hairs, and the use of which is to render
them less brittle. M. Gaultier thinks that there are nine
of these follicles, which are very small. -

The body of the hair embraces by its root the papilla of
the bulb from which it arises; it is joined to the papilla
in this place, nearly im the same way as horns and feath-
ers are united to the elongations which serve for their
support. In the interior of the bulb, the hair is covered
by a sheath which is furnished by the epidermis, and
which is evident in the quills of quadrupeds, and especi-
ally in feathers ; this sheath is discontinued at the place
where the hair traverses the skin to go out, or at least it
cannot be traced beyond there, perhaps because it is
broken off even with the integuments.

The structure of the hair itself is a point that is not:
yet well understood. This part seems to be, like the
feathers, horns, scales, &c. a production of the horny
layer of the skin; but it is difficult to ascertain the in-
ternal arrangement of the substance which composes it.
The bristles of the wild boar are formed by twenty fila-
ments leaving in their interstices one or two canals which
contain a peculiar marrow. On the contrary the hairs of
the elk, hedge hog, &c. have no filaments; they are con-
stituted by a horny tube, filled with a spongy and coloured
substance. Hence there are two different opinions in
relation to the structure of the hairs in man. Some pre-
tend that they are filaments in juxta-position ; according
to others, their arrangement is that of a tube. Both of
these opinions seem to be equally well founded ; Ist, on
the one hand, by examining against the light a black hair,
the edges of it are whitish and transparent, which seems ©
to show that the exterior of the hair is of a different
nature from that of the interior, but which may be also
owing to this, that the edge being thinner, the colour

294 ADDITIONS TO THE

must be less evident in it; 2d, on the other hand, the
hairs in man can be divided into many filaments, which
either depends upon their structure, or ‘the division is
purely mechanical. On the whole, the minuteness of the
objects prevents us from deciding on this subject. Only
it is certain that there is a colouring matter in. the hair,
and ‘that. this matter occupies the interior of it. The
hair is dyed with such substances as the preparations of
lead which only colour it by the chemical action they
exert upon this matter. But it is not. known whether it
undergoes a’ sort of circulation in-the hairs, or if when
once deposited, it is wholly beyond every motion of the
fluids. This matter is secreted with the hair itself within
its horny substance. 2 : ty

From all that precedes, it is evident that the t two sah.
ments of the hair, the bulb and the body or the hair
properly so called, have nothing’ in common in their
structure, and consequently in their properties ; that the
hair, properly so called, is almost inorganic, like: the
epidermis and the nails, whilst its bulb on the contrary
enjoys a very considerable degree of vitality. Hence
why the hairs, though insensible themselves, : transmit
such painful impressions when they. are pulled; why
they are so useful in animals with whiskers, as organs of
feeling, the least jar which agitates their extremity being
felt in an instant ; why, in. diseases, the hairs are influ-
enced by various organs, the functions of their. bulbs being
deranged by their connexion with the other functions ;
and why nevertheless they remain most often foreign to
all the disorders which take place in the economy, and
do not feel them for a length of time, &c. This sort of
productions. should be considered as the result of a real
excretion of which the bulbs: are the seat... Thus the
hairs grow only at their base, like the nails, of which it

PILOUS SYSTEM. 9 gs

is easy to be convinced by observing this growth upon
hairs artificially dyed, or upon which an indelible mark
has been made; the distance of this mark from the sur-
face of the skin increases only as the hairs lengthen; and
it is only near this surface that the colour of the hairs
which have been dyed seems to disappear, in proportion
as their substance is developed anew there. The cele-
brated Mascagni has again brought forward, in a post-
humous work, an opinion which has been many times
before thrown out upon the structure of the epidermoid,
horny and pilous parts; he regards them as a texture of
lymphatic vessels, and he attributes the same texture to
the enamel of ‘the teeth and to most of the organic tex-
tures. But this vascular structure, which Hedwig» has
represented with so much truth in the epidermis of plants,
does not appear to exist in the epidermis, hairs and. nails
of man and animals.

|

MORBID ANATOMY OF THE PILOUS SYSTEM.

Preternatural whiteness is the most common alteration
of the hairs. Much has been said of the hairs haying
become suddenly white, and over the whole extent of the
cranium at the same time; Bichat has even cited exam-
ples of this fact. But have these cases been sufficiently
observed? They should be doubted, I think, especially
as no one of them has been related with the necessary
details, until new observations confirm or destroy them.
If the-facts are correct, they would tend to prove that
there is circulation in the hair. Those that are well

296 _ ADDITIONS TO THE

known only prove that an appearance of sudden dis--
colouration may take place, when the hairs fall out and
are replaced by others of a different eolour. This is what
is often seen in phthisical subjects who have intervals of
almost perfect health; it then happens that their hair,
which had become white during the paroxysm, falls out
and is replaced by black, which it was before; Dr.
Chaumeton exhibited this phenomenon a short time be-
fore his death. This may be repeated many times suc-
cessively, and the hairs may be thus alternately coloured
and colourless according to the general state of the in-
dividual. In ordinary cases, the change of colour does
not take place in all the hairs at once, but successively
in each of them; it begins at the root and gains litle
by little; in proportion as this is extended and the end
worn by the action of foreign bodies; this is easily ex-
plained by the change that comes on in the secretion that
is made in the bulbs.

Alopecia (or the falling out of the hairs) is accompanied,
under some circumstances and ‘not under others, by a sort
of atrophy of their bulbs. This lesion is sometimes the
consequence of a long-continued irritation, as in tinea ;
at other times, though rarely at the present day, it is
owing to syphilis; but an infinity of other causes may
also produce it. The state of the bulbs in these different
cases has not been examined.

The plica is an affection also, the nature of which: is
but little known. The best observers are not agreed as
to what takes place in this disease ; according to some,
the hairs acquire sensibility, and are penetrated with
vessels ; others assert that they are only matted together.
It would be possible to reconcile these two opinions by
admitting that the hairs become merely vascular at their
base, by an extraordinary growth of the papilla contained

PILOUS SYSTEM. 297

in their bulbs, a growth which would raise this papilla
above the level of the external face of the skin, and
whose primitive irritation having eaused the disease, or
that secondary one resulting from want of cleanliness,
pulling the roots of the hairs, &c. would easily explain
it. The pliea would then produce a phenomenon analo-
gous to what is observed in feathers, in young birds; if
the papille of their feathers exceed the level of the integu-
ments, they bleed when they are cut.

Preternatural hairs are met with, besides under the cir-
eumstances noticed (Vol. 3d,) on the surface of the skin,
and in consequence of the inflammation of this membrane;
M. Boyer mentioned in his lectures the case of a woman
whose thigh was covered with long,.rough hairs, after
erysipelas. Among the cysts which contain hair, should
be noted those situated in the superior eyelid, near the
eyebrow ; their hairs resemble completely those of the
eyebrow, and appear to be only some of them which
have deviated from their usual direction. The hairs con-
tained in the cysts of the ovarium are delicate, silky,
light coloured, usually free from all adhesion and some-
times swelled at one of their extremities. It is extreme-
ly rare that hairs arise in cysts formed in other parts.
Hairs are sometimes found in the meconium of new born
infants ; their origin is but little known ; it is supposed
that they existed originally on the skin of the foetus.

38

PRETERNATURAL TEXTURES.

IT remains for us, in order to complete the summary
notice of the principal changes which the organic tex:
ture undergoes’in diseases, to speak of the degenerations
common to all the systems previously studied, and which,
not belonging in their nature tovany single one of them,
could not be examined in their particular history. The
description of these degenerations will be at the same time
a sort of completion of the General Anatomy, the different
simple textures of which have embraced, in addition to
the natural organs of the economy, only the preternatural
productions which are analogous to these organs. In fact,
the degenerations, though always resulting from a species
of transformation or degeneration which affects the natural
textures in consequence of the morbid phenomena of
which these textures are the seat, are really, when once
formed, independent to a certain extent, of these textures,
have in the midst of them their peculiar life, seem as it
were to be new organs superadded to all the others, so
unlike are they to those which have given them birth,
and are entitled from their structure and peculiar proper-
ties to form a distinct class, or if it be preferred, a system,
under the name of morbid or preternatural textures.

300 PRETERNATURAL TEXTURES.

These textures, considered ‘in this point of view, pre-
sent a certain number of common characters, which at
the same time mark the difference between them and the
natural textures of the economy. ist. Their structure is
in general homogeneous, and though they seem to contain
various organized elements, as vessels and cellular tex-
ture, those fibres and laminze which characterize most of
the organic textures are not seen in them. 2d. They
have not, like them, a uniform organization; their most
important properties, such as colour and consistence,
change in their different periods; in general hard and-
firm in the beginning, they soften and become fluid even
in part, ata more advanced period, which is precisely
the reverse of the other textures. 3d. Far from being
able to perform uses in harmony with the other functions,
as is sometimes done by the natural textures when pre-
ternaturally developed where they ought not to exist,
their presence always produces more or less remarkable
derangements in the aetion of the organs; emaciation,
slow fever and death are often the consequences of them.
4th. They have not a permanent existence in the econo-
my, but have uniformly a tendency to be destroyed at a
certain period ; sometimes, it is true, this period is late,
and they remain for a long time in the same state, making
a part of the organization, like the natural textures, it is
especially at the period of their destruction that they
affect the health. 5th. The diseases which affect them
have a peculiar progress and effect ; thus inflammation
uniformly produces in them the greatest derangements
and a rapid destruction, which are propagated to the sur-
rounding parts. /

The different preternatural textures may be met with
in almost all the organs; but there are some which they
more particularly affect ; often in the same. subject, they

f

PRETERNATURAL TEXTURES. 301

are found distributed at the same time upon a great num-
ber of points. These textures frequently increase the
size of the parts which they occupy, and:form tumours
prominent on the exterior. Their apparent situation, in
relation to the organs, presents in general, two varieties ;
in one, they seem to be interposed between the textures
which compose these organs; in the other, these textures:
disappear, and are replaced by the preternatural pro-
duction. | i

How are these textures produced in the animal econ-
omy? Bayle and Laennec attribute their development
to a particular disposition of an unknown nature, which
exists in certain individuals, and regard the external
causes which are commonly assigned, at most as only
occasional circumstances, which favour the action of this
occult cause. Broussais, on the contrary, assigns to these
causes the principle part; according to him, these pro-
ductions are uniformly a result of inflammation, and take
place when, in this, the white vessels and the lymph
which they contain are especially affected, the irritation
not being sufficient to bring the red part of the blood;
the albumen variously combined with the textures, is the
basis of these productions. J.F. Meckel calls the prox-
imate, cause of this kind of alterations, and generally all
the alterations of texture, an abberration of the process
of growth ; he explains all these lesions in the same way,
as J. Hunter and Abernethy do, by the effusion of a fluid
albuminous matter, taking various forms and requiring a
peculiar and imperfect mode of organization. Others
consider them as productions analogous to the eryptoga-
mous vegetables, and which are nourished and grow
either by imbibition, or by a real vascular circulation.
Disregarding these theories, which are more or less well
founded, we shall treat only of the anatomical characters

302 PRETERNATURAL TEXTURES.

of the preternatural textures; whatever may be. the
origin of these textures, it is important to know them,

But they exhibit in this respect many differences,
which are not however striking, but are confounded with
each other by insensible shades; besides, the parts in
which they are situated, though not absolutely having an
influence upon their nature, make’ them’ however vary a
little, so: that the study of them becomes very difficult;
thus authors are not agreed in the. classifications which
have been given of them. Some have ‘made many tex-
tures of the same production examined at different periods
of its development; we have already noticed this. source
of error. Another, not.less real, is that oftentimes many
of these alterations are united together, whether they form
different distinct parts of one texture, or whether they are
intimately intermixed in this texture. This union may
take place not only between morbid textures properly
so called, but: also between these and the preternatural
textures to which there are analogous ones in the econ-
omy; the osseous and fibrous: productions, for example,
are often joined to the first, as is seen especially in the
ovarium, the thyroid gland, &e.. Hence it follows that
all these textures are far from being equally well known ;
that daily observation shows productions which do net —
resemble any of those hitherto described; and» finally
that’ there are very common alterations, as the polypi of
the mucous’ membranes, fungi of the dura-mater, &c.
that we know not where to class, and which appear to
consist sometimes in a simple hypertrophy, and some-
times in a real degeneration. The only preternatural
textures which have characters at all striking are, Ist,
Tubercles; 2d,Secirrhus; 3d, Cancer; 4th, Melanosis.
We shall now examine them in succession:

‘PRETERNATURAL TEXTURES. 303

I. Of Tubereles.

Tubercles, or scrophulous tubercles, so called from
their form which is commonly round and from their
most frequent cause, exist under many forms, which are
so many degrees of this degeneration, and which may be
all included in two periods, the one of crudity in which
they are in asolid state and the other of. softening. M.
Broussais considers this last as.atrue mode of suppuration
peculiar to this texture, and resulting, like ordinary sup-
puration, from the inflammation which is developed there.

First Period. Greyish granulations, semi-transparent,
quite firm, from the size of a-grain of millet to a grain of
hemp and irregularly distributed, usually constitute tuber-
eles in the beginning. Bayle, who observed them in the
Jungs in this. state, thought that it was an alteration dif-
ferent from tubercles; M. Laennec has proved that it. is
not. so. These grains, as they become larger, assume
another aspect; they often unite together, and form more
or less considerable masses ; they always become opake
and yellowish, at first in their centre, and then on the
circumference, nearly in the same way as cartilages which
are ossified, and acquire at the same time the consistence
of hard cheese. This state, which is properly that of the
crude tubercle, is not,always distinctly preceded by the
first, in which the tuberele is called miliary ; there
sometimes takes place in the beginning a sort of infiltra-
‘tion or impregnation of tubercular matter, which suddenly
invades a certain extent of the affected organ which be-
comes greyish, more dense and semi-transparent ; yellow
and opake spots afterwards appear in this place, and the
second state comes on.

304 PRETERNATURAL TEXTURES.

The tubercular texture adheres most often to the sound

texture which surrounds it, it sometimes even seems to
be continued with this texture, and at others, on the con-
trafy, it is separated from it with the greatest ease. In
some cases, a membrane in the form of a cyst surrounds
the tubercle; this is especially: when the tubercle is
developed slowly. This membrane is not always of the
same nature; sometimes soft, and as it were, like the
integuments of pork, sometimes more consistent, it some-
times. becomes cartilaginous and even osseous ; it appears
to be the result of an exudation.

The vessels are separated or obliterated by the tuber-
cular substance ; ; they are not visible in the masses which
it forms.

Second Period. The tata eo soften and eden as it were
from the centre to the circumference ; they are converted
sometimes into. an opake, thick, yellowish matter, which
very much resembles cream, sometimes into a clear and
transparent fluid, in which flakes similar to cheesy matter
are seen to swim, ‘The evacuation of these products has -
taken place, as in abscesses, sometimes externally and some-
times internally ; the centre of the disease, which is
usually lined by a membrane of new formation, analogous
to the cyst of which we have spoken aboye, cicatrizes, or
continues open, and brings on suppuration and ulceration
of the texture, which forms the parietes of it, or finally
remains always, but is clothed with a dry, semi-cartila-
ginous membrane, as was first observed by M. Laennec.

Wl. Of Seirrhus.

The scirrhus texture is firmer than the preceding ; its
consistence varies from that'of the cartilages to the soft-
ness of the inter-vertebral fibro-cartilages; it makes a

PRETERNATURAL TEXTURES. 805

noise under the scalpel. Its colour is white, slightly
blueish ; cut in thin slices, it appears semi-transparent.
It forms more irregular masses than the tubercular tex-_
ture ; it softens in the same way, and is then changed to
a transparent, greyish or reddish matter when a little
blood colours it, exhibiting the appearance of a jelly or
syrup.

The pancreatoid, mammary, (analogous to the texture
of the mamma,) and tubercular sarcomas of Abernethy
should be considered as varieties of scirrhous. In the last
of these three, the name of which is improper, since it is
agreed to give the name of fudercles a particular kind of
texture, and not a variety of form, the scirrhous mass is
divided into distinct lobes.

Ill. Of Cancer.

In pathology, various alterations have been designated
under this name, among which scirrhous, which we have
just examined, has often been comprehended. We shall
understand only by cancerous texture what some have
called soft cancer ; it is the cerebriform or encephaloid
matter of M. Laennec, the fungous inflammation of
Burns, the fungous hematodes of Hey and Wardrop, the
medullary sarcoma of Abernethy, &c.

This texture has less consistence than the scirrhous,
though it has more than the cerebral substance ; it is of a
milky white, variegated, when it is cut, by red points
formed by the divided vessels; these are in fact very
numerous in it; but their parietes are very thin, and
hardly bear the effort necessary for injection. The masses
which this texture forms are divided on their surface by
lobes convoluted nearly like those of the brain; a very

39

3506 PRETERNATURAL TEXTURES.

soft cellular texture fills the interstices of these lobes.
These masses occupy at first but a very limited extent,
and are afterwards propagated in all directions; this is
what ig seen, for example, in the eye, which is frequently
the seat of this alteration, and in which it occupies most
often in the beginning, a single point only of the retina,
from which it extends to the whole of the eye.

In the period of softening, which comes on soon in
this texture, and the progress of which is very rapid, it
assumes the appearanee of the softened cerebral substance,
and forms a sort of rose-coloured jelly, on account of the
blood which is mixed. with it; often even the rupture of
the vessels which pass through it, occasions real hemor-
rhages, and effusions of blood having some analogy with
those which the same cause produces in the brain ; there
is sometimes formed, in consequence of these exudations,
a membrane in the form of a cyst, as in apoplexies.

Besides, the resemblance is not perfect between the
cancerous texture and that of the brain, and we ought not
yet to admit the opinion of those who regard these tex-
tures as identical, and conclude from it that there is an
effusion of nervous fluid in the production of the first.

IV. Of Melanosis.

This production, thus named by M. Laennec, is united
to the preceding by J. F. Meckel. M. Broussais thinks
that it is a tubercular texture, the black colour of which
is owing to the advanced age of the individuals who are
the subjects of it; but it is not proved that old people
are the most frequently affected with it. The same author
makes a more accurate approximation perhaps, between
this colour and that of the membranes in which the blood

PRETERNATURAL TEXTURES. 307

has remained for a long time, as in consequence of some
phlegmasias of long standing.

Melanosis should be distinguished from the black mat- »
ter of the lungs. The latter, which is found in most
subjects after the age of from twelve to fifteen years,
which increases progressively with age, and which tinges
the bronchial glands, the surface of the lungs and the
interstices between the lobules, does not constitute a
disease. |

The black colour of this texture is perfect and entirely
opake ; its consistence is considerable ; and it resists ef-
forts made to tear it. It accumulates sometimes in masses
of a certain size ; at other times it forms striz or plates,
‘more or less extensive. . Its interior appears to be homo-
geneous ; no kind of structure is discoverable in it. This
matter rarely becomes soft; when this does take place,
there results from it a sort of black pap or a serous fluid,
mixed with a grumous matter of the same colour.

Melanosis is much more compatible, than the other
morbid textures, with a state of health ; so different is its
nature from that of these textures. M. Barruel, chief of
the chemical department of the Faculty of Medicine, has
recently examined for me some melanosis extracted from
a mare, which had a great quantity of it in the muscles,
in many viscera and especially under the skin of the
perineum and the mammez; it appears from his exami-
nation that melanosis must be considered as a mass of
matter coloured with blood and fibrin, both in a peculiar
state, and in which is found a little albumen, three dis-
tinct fatty substances, and much of the phosphate of lime
and iron. |

ANALYTICAL TABLE OF CONTENTS.

ADDITIONS TO THE GENERAL OBSERVA-
TIONS.

PAGE
Anatomica). Elements.—Attempts have been made to dis-
cover what are the primitive elements of the tex-
tures.—Elementary fibre of the ancients.—There are
three elements ; the cellular, nervous and muscular
fibre.—The albugineous fibre considered as a fourth
element.—Elementary forms.—-—Their division.—

Opinion of J. F. Meckel. -16
Classification of Morbid Anatomy.—Method followed by
the moderns. —Classification of Meckel.—Order that

we shall adopt. 22

ADDITIONS TO THE CELLULAR SYSTEM.

Adipose Texture-—Names which different authors have
given to this textare—External Forms.—Organiza-
tion.—Blood Vessels—Cellular Texture-—Unknown
Absorbents and Nerves.—The Adipose Texture re-
sembles the Cellular—Characters which distinguish
them. 27

310 ANALYTICAL TABLE

PAGE

Chemical Nature of the Fat.—It is formed of two princi-
ples elaine and stéarine—Their characters.—Means
of separating them.—Their proportions vary.—The
fat is fluid in the living body.—Acids which the fat
furnishes when it is treated with alkalies.

Intimate Nature of the Cellular Texture—The ancients
appear not to have known this texture.—Authors who
have described it successively —Opinion of Bordeu
adopted by some moderns,—Facts upon which they
are founded.—It is to be determined by inspection.

-MORBID ANATOMY OF THE CELLULAR
SYSTEM.

I. Alterations in the External Forms.

Anasarca.—Fatty Tumours.—Emphysema.—Hardening
of the Cellular Texture.—Elephantiasis.

Il. Alterations in the Organization.

Phlegmon.—Mode of adhesion of the divided cellular
texture.—Cicatrization of this texture laid bare.—
Phenomena that foreign bodies produce in ‘it.—Some-
times these bodies remain without producing any in-
convenience.—Animated foreign bodies.—Osseous and
cartilaginous transformation.—Fibrous, Serous and Mu-
cous transformations.—Various degenerations.

III. Alterations in the Development. -

Preternatural development.—Membrane of the fleshy
granulations.—How it is formed.

32

33

37

38

Al

OF CONTENTS.

X

$11

ADDITIONS TO THE NERVOUS SYSTEM OF

ANIMAL LIFE.

PAGE

Nerves which the Brain furnishes—The optic nerve does
not come from the brain, but from the medulla
oblongata.—The origin of the olfactory is not well
known.—The olfactory bulb of animals.—It is con-
tinued with the peduncles of the medulla oblongata.—
The pulpy portion of the olfactory nerves in man is
analogous to it, according to some anatomists.

Origin of the Nerves——They arise from the grey sub-
stance.—Arrangement of this substance in the spinal
marrow.—lIt exists also at the origin of the cerebral
nerves.—It should be inferred from this, that it pro-
duces the nervous substance.

Crossing of the Nerves——It takes place in the medulla
oblongata.—Consequences in relation to paralysies.
Composition of the Nervous System.—Principles that M.
Vauquelin has found in it—Properties of the two pe-
culiar fatty substances.—Proportions of these principles

in the spinal marrow and in the nerves.

Texture peculiar to the Nervous System.—Two substances.
—White substaace.—The cerebral substance is com-
posed of fibres.—Method of studying its structure.—
Course of those of the fibres which come from the
medulla oblongata.——Fibres of the commissures.—
Structure of the cerebellum.—The substance of the
nerves has also fibres.—This is likewise the case with
that of the spinal marrow.—Arrangement of these last.
—Grey substance.—lts arrangement.—lIts structure.—
The microscope besides discovers globules in the
nervous texture.—They resemble those of the blood.
—Substance which secretes them.—Arrangement of
these globules—T hey do not appear to be the seat of
the colouring matter in the grey substance.

Development of the Nervous Centres.—Various authors
have been engaged with the subject—The dimen-
sions of the cerebrum, cerebellum and spinal marrow
are in an inverse proportion at the different periods of

43

44

46

47

4&

oie. ANALYTICAL TABLE

PAGE

gestation.—Fissure which divides all these parts in
the beginning.—The conformation of the cerebrum,
at first very simple, becomes gradually complicated.
Development of the cerebellum, the cerebral protu-
berance, and the spinal marrow.—Texture of the
encephalon at the different periods——The white sub-
stance appears before the grey.—Exception, according
to M. Serres, with regard to the thalami nervorum op-
ticorum and the corpora striata— The vessels precede
beth substances.

Development of the Nerves.—Period at which they appear.
—lIt is not the same for all— Development of their tex-
ture.

53

59

MORBID ANATOMY OF THE NERVOUS SYS-

TEM OF ANIMAL LIFE,

I. Alterations in the External Forms.

Increase of size in the nerves.—Diminution.—The brain
diminished in size.—Softening of the nerves.—Hard-
ening and softening of the brain.—Softening of the
spinal marrow.—Alterations of situation and form.

II. Alterations in the Organization.

Inflammation.—In the nerves.—In the brain.—Mode of
reunion of the nerves.—Nature of the cicatrix.—
Opinion of Arnemann.—What takes place at the supe-
rior end in amputations.—Solutions of continuity in
the brain and the spinal marrow.—Osseous, fibrous
and cartilaginous transformation.—Cysts.—Degenera-
tions.

III. Alterations in the Development.
Defects of conformation.—Partial and total absence.—

Irregularities of forms.—Congenital affections —Ana-
tomical varieties—No preternatural development.

60

62

65

OF CONTENTS. 313

\

ADDITIONS TO THE NERVOUS SYSTEM OF
| ORGANIC LIFE.

PAGE
Insulation of the Great Sympathettc——Opinions of authors
upon this insulation—Experiments of Legallois.—Op-
posite experiments.—Conclusion that must be drawn
from them. .
Structure of the Ganglons—They contain the two sub-
stances pointed out by Scarpa—Arrangement of the
nervous filaments in their interior.—Peculiar grey
substance.—It differs from the cerebral.—It does not
appear to be changed into fat in fat subjects, as Scarpa
Said. 70
Uses of the Ganglions.—They are of two kinds, accord-
ing to physiologists.—Idea the most generally admit-
ted. 73
Ganglions of Animals—The nervous system of the lower
classes. of animals has hardly any analogy with that of
the superior animals, though many have attempted to
shew approximations.—What is called a ganglion in
the former, dows not perhaps deserve that name.—
In the vertebral animals, the development of the gan-
glions varies according to many circumstances. 75

67

ADDITIONS TO THE VASCULAR SYSTEM
WITH RED BLOOD.

Situation of the Arteries—They are almost everywhere _
situated in the direction of the flexion of the articula-
tions.—Advantages of this arrangement.—They are in
general on the internal side of the limbs. 77

Termitation of the Arteries.—Differences in the length of
their course, in their mode of distribution, their num-
ber and size, and in the net-works which their divisions
form. ; 78

40

314 ANALYTICAL TABLE

~ PAGE
Resistance of the Arterves—Membranes which support the
effort, according to the direction in which it is made.—
Causes which have an influence upon this resistance.
—Experiments of: Wintringham and Gordon.—Differ-
ence between the convex and concave side of the arte-
rial curves. 80
Nature of the Middle Coat of the Arteries.—Reasons alleged
by those who believe it muscular.—They are not suf-
ficient to make us regard it as such.—T his coat belongs
to the yellow fibrous system. 8t
Cellular Membrane and Sheath of the Arteries.—Characters
of the celiular membrane.—Arrangement of the cellu-
lar texture around it—What should be understood by
the cellular sheath of the arteries.—Varieties which it
exhibits.—T hese varieties explain various morbid phe-

nomena. 82
Nerves of the Arteries.—The branches have more of them

than the trunks.—Mode of their distribution. . 84
Irritability of the Arterial Teaxture—Reasons assigned.
by those who admit it—Experiments of Verschuir,
Bikher, Vanden-Bos, Giulio, Rossi, Home and 'Thom-
son.—Other facts—-Consequences.—The contraction
of the arteries is more evident in the smal! ones. 85
Action of the Arteries in the circulation—T he, contraction
of the arteries is one of the causes of the motion of
the blood. 87
Development of the Vascular System.—It is a point still
obscure.—Result of the researches made upon the
chick.—C onsequences. 88

MORBID ANATOMY OF THE VASCULAR SYS-
TEM WITH RED BLOOD.

bi Alterations in the External Forms.

Increase of size of the arteries —T heir growth in length.
—Their partial dilatation (aneurism).—T heir uniform
dilatation.—Contraction of the arteries.—It may extend

OF CONTENTS, 315

PAGE
to obliteration —Change in the mode of distribution of
the arteries, in consequence of the obliteration of a
principal trunk. 90

Il. Alterations in the Organization.

Inflammation of the internal membrane.—Obliteration
which results from it—Mode of adhesion of the arte-
rial parietes.—Other terminations of this inflammation.
—Alterations peculiar to the surrounding cellular tex-
ture.—Brittleness from inflammation of the cellular
coat.——Peculiar redness of the internal membrane
resembling its inflammation.— Wounds of the arteries.
—Results of experiments upon dogs.—Punctures heal
perfectly.—In the more extensive wounds, the termi-
nation differs according as the cellular sheath is un-
touched or not.—What takes place in transverse divi-
sions.—T he progress of these wounds is a little differ-
ent in man.—Solutions of continuity which affect only
one part of the membranes.—Experiments.—In what
consists the internal mixed aneurism.—Rupture of the
internal membranes.—lts~ consequences in different
cases.—Foreign bedies applied to the arteries.—Ossi-
fication of the arteries —Cartilaginous transformation.
—Fibrous and Cellular transformations.—Degenera-
tions peculiar to the arterial texture. —Fungi.—Ex-
crescences.—Pultaceous matter—Common degenera-
tions 92

III. Alierations in the Development.

The varieties of the arteries are numerous.—Some only.
are important in relation to the circulation.—Preter-
natural development of the arteries. 102

ADDITIONS TO THE VASCULAR SYSTEM
WITH BLACK BLOOD.

Venous Valves— Their number in the different parts.—
Arrangement of their edge.—Dilatation of the vein
where they are situated.--Their structure.—Their
differences. 105

316 ANALYTICAL TABLE

es PAGE
Contractility of the Veins-——The veins have a vital action.
—Facts which prove it—Their mode of contraction

cannot be referred to any other. 107
Venous Circulation.—Opinion of Harvey.—Influence of
the heart upon this circulation. 108

Development of the Venous System.—A part of this system
is developed before the arterial—Doubts in relation
to the development of the aorta.—Most of the veins
are formed after the arteries. 109

MORBID ANATOMY OF THE VASCULAR SYS-
TEM WITH BLACK BLOOD.

I. Alterations in the External F orms.
Dilatation of the veins.—Their contraction. 110
II. Alterations in the Organization.
Inflammation.—Cases in which it is observed.—Effects
which result from it.—Disorders which it produces.—
Adhesive inflammation.—Venous ruptures.—Aneuris-
mal yarix and varicose aneurism.—Osseous transfor-
mations.—Concretions found in the veins. 111

(II. Alterations in the Development.

Frequency of anatomical varieties compared with that of
the arteries.—Preternatural development. 114

ADDITIONS TO THE CAPILLARY SYSTEM.

Continuation of the Arteries with the Veins, Exhalants, &c.
—vVarious opinions of the ancients.—Proofs of the con-
tinuation of the arteries with the veins.—The continu-
ation with the exhalants and excretories is less certain. 115

OF CONTENTS. 317

PAGE
Erectile Texture—This texture is entirely vascular, as
various anatomists have proved.—Phenomena of which
it is the seat—Organs which this texture composes. 116
Capillary Circulation.— Proofs that the heart has an in-
fluence upon it. 119

MORBID ANATOMY OF THE CAPILLARY
SYSTEM.

- |. Alterations in the External Forms.
Preternatural growth. 120
Il. Alterations in the Organization.

Effects produced by contusion and concussion.—Wounds. 121
III. Alterations in the Development. 2

Preternatural Development.—Its mechanism.—Preter-
natural erectile texture. 121

ADDITIONS TO THE EXHALANT SYSTEM.

Arrangement of the Exhalant Vessels-—Their existence is
not proved.—There are however white vessels.—
Experiment of Bleuland.—We are ignorant of the mode
of the termination of these vessels. 125

ADDITIONS TO THE ABSORBENT SYSTEM.

Origin of the Absorbents——What is known of this origin.
—Observation of Cruikshank.—Experiment of Mas-
cagni.—Result of injections. 127

Venous Absorption.—Termination. of the Absorbents.—Dif-
ferent opinions respecting venous absorption.—Facts
which prove this absorption.—Consequences.—Obser-
vation of Abernethy. 128

f

318 ANALYTICAL TABLE

PAGE
Structure of the Lymphatic Glands.—The opinion rejected
by Bichat is that of Mascagni and Gordon.—Considera-
tions in support of this opinion.—Cellular texture,

veins and nerves of the lymphatic glands. 129
Properties of the Absorbents.—Sensible Organic Contrac-
tility—Facts which demonstrate this property. 131

* MORBID ANATOMY OF THE ABSORBENT’
SYSTEM.

I. Alterations in the External Forms.
Dilatation of the absorbent vessels. 132
II. Alterations an the Organization.

Inflammation.—W ounds.—Spontaneous ruptures.—Ossifi-
cation of the lymphatic glands.—Their tubercular
affection. 132

Il. Alterations in the Development.

Frequency of anatomical varieties—The thoracic duct
exhibits a great number of them. 133

ADDITIONS TO THE OSSEOUS SYSTEM.

Intimate Structure of the Bones.—Various opinions.—Ex-
amination of the facts in relation to these opinions.—
There appear to be in the bones lamin, fibres and
areole. | | 135

Arrangement of the Pores of the Compact Texture. 137

Composition of the Osscous Texture.—Analysis of M. Berze-
lius.—Difference observed by other chemists——Com- _
position of the bones in an anatomical point of view. _—_2b.

Veins of the Diploe—Their arrangement.—They exist in
different bones. : 139

OF CONTENTS,

Development of the Osseous System.—Authors who have
been particularly engaged with this subject—All the
bones are not at first cartilaginous.—Period at which
the osseous state begins in the different bones.—
Changes which the cartilage that is ossified undergoes.
—Ossification examined in the long and broad bones.—
Mode of increase in the length of the long bones.—
{Increase in thickness in the three species of bones.
—Changes which the cavities of the bones undergo.—
Other changes which tale place in this system in old
age.

Sectad Dentition considered at the period of cutting.—Error
that should be corrected in all the editions of the work
of Bichat.

MORBID ANATOMY OF THE OSSEOUS
a: SYSTEM.

I. Alterations in the External Forms.

Tumours of the bones.—Increase of density of the osse-
ous texture.—Atrophy of this texture.—Softening.—
Effect of compression upon the bones.—Changes in the
natural relations of the bones.—False articulations.

II. Alterations in the Organization.

Suppuration of the bones.—Necrosis.—Reproduction of
the bones in this affection —Denudation of the bones.
—Fractures.——Mechanism of the formation of the
callus—What should be thought of the opinions of
authors upon this subject—Fibreus reunion of cer-
tain fractures.—Various transformations and degene-
rations.

II. Alterations in the Development.

319

PAGE

139

145.

146

149

Defects of conformation,—Preternatural osseous texture. 155

320 ANALYTICAL TABLE

ADDITIONS TO THE MEDULLARY SYSTEM. :

PAGE
Organization of the Medullary Membrane.—Experiment
which renders it more conspicuous.——Vessels and.

nerves of this membrane.—Adipose vesicles. 157
Sensibility of the Medullary Membrane. 158.
Development. 159 ©

Functions—The marrow does not transude in order to
produce the synovia.—Other hypothetical uses attri-
buted to the marrow.—lIts trne functions and those of
the medullary membrane. ' 160

MORBID ANATOMY OF THE MEDULLARY
| SYSTEM. |

This system is no doubt altered in syphilis—Changes
which it undergoes in various cases.—Spina ventosa is
a cancer of the medullary membrane.—Alterations of
the marrow in phthisical patients. 161

ADDITIONS TO THE CARTILAGINOUS SYSTEM.

Peculiar Texture.—Its organization is not very apparent.

—Various opinions. 163
Chemical Composition.—Results obtained by modern che-
mists.— Differences according to age. 165

MORBID ANATOMY OF THE CARTILAGINOUS
SYSTEM.

I. Alterations in the External Forms. 166
Il. Alterations ta the Organization.

Inflammation has not been observed in the cartilages.—
What takes place when they are denuded or broken.

OF CONTENTS. 7 391

| PAGE

—Reproduction of the cartilages.—Osseous transfor-

mation. : 167
Il]. Alterations in the Development.

Defects of conformation.—Preternatural cartilaginous
textures. 169

ADDITIONS TO THE FIBROUS SYSTEM.

Yellow Fibrous Texture.—It forms a distinct class in the
fibrous system.—It is placed wherever a continual re-
sistance is required.—lts differences from the white
fibrous texture.—Its properties.—lIts uses, 171

MORBID ANATOMY OF THE FIBROUS SYSTEM.

I. Alterations in the External Forms.

Thickenings of the ligaments and tendons.—Stiffness
which they acquire under some circumstances. 173

Il. Alterations in the Organization.

- Inflammation.—Mode of reunion of divided fibrous or-
gans.—Ossification rare.—Degenerations. 174

III. Alterations in the Development.

lielaxation of the ligaments in some defects of conforma-
tion.—Preternatural fibrous texture—Fibrous body. 175

ADDITIONS TO THE FIBRO-CARTILAGINOUS
SYSTEM.

Of the Nature of the Membranous Fibro-cartilages.—They
ure true cartilages. — 179
O} the Forms of the Fibro-cartilaginous System.—They are
very various.—Table of this system. 180

41

322 ANALYTICAL TABLE

MORBID ANATOMY OF THE FIBRO-CARTI-
LAGINOUS SYSTEM. —

PAGE

I. Alterations in the External Forms. 182

Il. Alterations in the Organization. ab.

II]. Alterations in the Development.—Preternatural fibro-
cartilages. 183

ADDITIONS TO THE MUSCULAR SYSTEM OF
| ANIMAL LIFE.

Intimate Structure of the Muscles—Divisibility of the mus-
cular fibre.—Size of this fibre—Inequalities which it
exhibits on its surface.—Microscopical observations.—

Is the muscular fibre solid or hollow. 185
Influence of the Nerves upon Muscular Irritability.—What
takes place when all the nerves of a muscle are cut.—
—Consequences.—~-Many physiologists consider the
nerves only as conductors.—It is difficult. to resolve
the question in an absolute manner. 187
Quickness of the Muscular Contractions.—Measure of this
quickness.—Method of Dr. Wollaston for estimating it. 190
Size of the Muscles in Contraction.—Causes of error in the
experiments made to determine it—Observation of
Erman. 191
State of the Circulation in the Muscles in Contraction.—lIt is
more rapid according to. some physiologists.—Exami-
nation of the facts upon which they are founded.—

This opinion is by no means demonstrated. 192
State of the Muscles after Death.—Stiffness in the dead body.
—lIts causes.—Varieties.—Seat. 194

ae

ADDITIONS TO THE MUSCULAR SYSTEM OF
| ORGANIC LIFE,

Influence of the Nervous System upon the Muscles of Organic
Life.—It is difficult to determine it—Influence of the

’

OF CONTENTS. 323

PAGE
brain upon the contraction of these muscles.—Influ-
ence of the spinal marrow and the nerves. 197

Duration of the Organic Contractility.—It varies in different
muscles.——Order in which this property is extin-
guished. 200

Force of Dilatation of the Muscles.—Many facts have been
incorrectly referred to this force.—Its existence is
doubtful. ) 201

MORBID ANATOMY OF THE MUSCULAR |
SYSTEM.

I. Alterations in the External Forms.

Hypertrophy and atrophy.—T he pretended fatty degene-
ration belongs to this last—Softening of the muscles.
—KEffect of their elongation ——Their shortening and
displacement. 204

_ Il. Alterations in the Organization.
inflammation.—W ounds.— Transformations. 205
Ill. Alterations in the Development.

Defects of conformation.—Preternatural muscular tex-
ture. 206

ADDITIONS TO THE MUCOUS SYSTEM.

Villa of the Mucous Membranes.—Forms of these villi seen
through a microscope.—Various opinions upon their
structure.—Upon the termination of the lymphatic
vessels on their summit.—The existence of nerves in
these villi is not demonstrated.—Their blood vessels
and lymphatics are evident. 209

Mucous Glands.—They are follicles and nat properly
glands.—T heir arrangement.—There are simple and
compound ones.—Arrangement of these last.—Peculiar
depressions of the mucous membranes.—Classification
of the follicles by Home.—Follicular secretion. 212

324 ANALYTICAL TABLE

Development of the Mucous System.—It is continuous, in

the first period of conception, with the membranes of

the ovum.—Development of the intestine in the chick.
—Applications to man.—Other ideas on this subject.

PAGE

216

MORBID ANATOMY OF THE MUCOUS SYSTEM.

J. Alterations in the External Forms.

Dilatation and contraction of the mucous ducts.—Adhe-
sions.—Hypertrophy of the mucous membranes.—De-
fects of situation and form.

Il. Alterations in the Organization.

Infammation.—False membranes.—Cicatrices of the mu-
cous membranes.—T'ransformations.—Cancer.

II. Alterations in the Development. |

Their two kinds are distributed unequally in the different
systems.— Defects of conformation in the mucous sys-
tem.—Preternatural mucous membranes.

ADDITIONS TO THE SEROUS SYSTEM.

I. Alterations in the External Forms.

Increase of nutrition.—It becomes thinner and is dis-
placed. | .

Il. Alterations in the Organization.
Alterations of the serous fluids in consequence of inflam-

220

222

223

227

mation.—They explain most of the changes which .

this affection produces in the serous membranes.—
Reproduction of the serous texture.—Ossification.—
Various degenerations.

LL. Alterations in the Development.

Defects of conformation.—Preternatural serous mem-
branes.—Cysts.—Mode of production of cysts —'Their
organization.—Substances which they contain ——How
they are distinguished from hydatids.

229

OF CONTENTS. 995

ADDITIONS TO THE SYNOVIAL SYSTEM.

PAGE
Conformation of the Synovial Membranes.—Proofs that —
they form sacs without an opening. 236
Synovial Fringes—Their nature and arrangement.—All
the synovial membranes have them.—'Their differ-
ences, situation and uses.—Analogous fringes in the
mucous system. 239
Parallel between the Synovial Membranes and the Serous Ones.
—There are fewer vessels inthe synovial membranes.
—The structure of these is more distinctly fibrous.—
They seem to be less extensible. 241
Existence, Forms and Organization of the Synovial System of
the Tendons.—T his system is gradually confounded with
the cellular.—Circumstances which have an influence
upon the number of the tendinous synovial membranes,
—Manner of observing these membranes.— Differences:
in their forms, structure, fluid and properties. 242

MORBID ANATOMY OF THE SYNOVIAL
SYSTEM.

I. Alterations in the External Forms.
Dropsy.— Adhesions. 245
Il. Alterations in the Organization.

Different effects of inflammation.—Foreign bodies in the
articulations.—T hey exist originally without the syno-
vial membrane.—Their different states——Impressions
which they sometimes produce.—Peculiar bodies found
in the burse mucose.—Alterations of the synovial
membranes in white swellings. 246

II. Alterations in the Development.
Preternatural synovial membranes. 248

396 ANALYTICAL TABLE

ADDITIONS TO THE GLANDULAR SYSTEM.

PAGE
Intimate Structure of the Glands—The opposite results ob-
tained by Ruysh and Malpighi are owing perhaps only
to the diversity of the texture of the glands. 249
Influence of the Nerves upon the Action of the Glands——This
action is in general but little known.—Difficulty of
ascertaining the influence of the nerves.—Experi-
meats which render it doubtful. 251

MORBID ANATOMY OF THE GLANDULAR
SYSTEM.

I. Alterations in the External Forms.

Hypertrophy and atrophy.—Changes of colour, consist-
ence and situation. . 253
II. Alterations in the Organization.

Inflammation.—W ounds.—T ransformations. 254

Ill. Alterations in the Development.

Anatomical varieties. 255

ADDITIONS TO THE DERMOID SYSTEM.

* Colouring Matter —Mucous Body.—Papille.—Layers of

the mucous body.—This body is not admitted by all
_ anatomists.——Experiments in order to obtain the
colouring matter.—Its mode of production.—It is in
circulation in the skin.--Examination of the other
parts of the mucous body.—Sanguineous bunches and

papille.—Their arrangement and structure. 257
Cutaneous Absorption —Absorption by contact is not de-
‘monstrated.—Gaseeus absorption. 263

Sebaceous Glands.—Proofs of their existence.——Their
structure, 266

OF CONTENTS.

-

MORBID ANATOMY OF THE DERMOID

SYSTEM.

327

sd PAGE

I. Alterations im the External Forms.

Changes which the skin when distended undergoes.—
Preternatural growth of the different parts of the skin.
—Horny productions.—Increase of the sebaceous fol-
licles—'Tumours which result from it.—Cutaneous
atrophy,—Bunches on the skin and thickening of it.

TL. Alterations in the Organization.

Effects produced by inflammation.—Simple wounds of:

the skin.—Denudation of the dermis—Mucous and
cartilaginous transformations.—Cancer.

Ill. Alterations in the Development.

Defects of conformation.—Preternatural cutaneous tex-
ture (cicatrix).—Various kinds of cicatrices.—Mecha-
nism of cicatrization.—Characters of the new cutane-
ous texture. :

268

a

a

275

ADDITIONS TO THE EPIDERMOID SYSTEM.

Means of Union of the Epidermis with the Dermis-—Exhalant
and Absorbent Pores.—lNature of the elongations inter-
mediate between the dermis and the epidermis.—
Doubts upon the existence of the pores. .

Epidermis of the Mucous Membranes.—It is not known
whether the deep-seated mucous membranes have an
epidermis.—Line of demarcation apparent in: some
places between the superficial and the deep-seated
mucous membranes. ©

Nature of the Nails —They are a dependance of the horny
laver.—Analogous parts in animals.—Mode of forma-
tion of the naiis and the horns.—Longitudinal strie of
the nails. :

981.

284

286

p2il «

*

x ue %

328 ANALYTICAL TABLE OF CONTENTS.
=.

MORBID ANATOMY OF THE: ae | stn hora
Saat

PAGE
Various Alterations of ae Epidermis.—-lis destruction.— :
Excrescences of the nails.—Other alterations of the
nails.—Nail entering the flesh. 288

¥

ADDITIONS TO THE PILOUS SYSTEM.

Structure of the Hairs.—Arrangement of their bulb.—Or-
ganization.—Body of the hair—T'wo opinions upon its
structure. ———Colouring matter on the hair——Conse-

_ quences. alles . 291

oe

MORBID ANATOMY OF THE PILOUS SYSTEM.

Whiteness. Alopecia. —-Nature of the Plica.—Preter-
natural hairs. 295

PRETERNATURAL TEXTURES.

Their description belongs to general anatomy.—-Common
characters._-General arrangement.—Mode of produc-
tion.— Differences. 299

I. Of Tubercles—They have two periods.—1st Period ;
miliary or crude tubercles.—Cyst of the tubercles.—

2d Period; softening.—Various terminations. 303
i, Of Scirrhus.—-Its anatomical characters.—lts varie-
ties. 304
Ill. Of Cancer._—Synonyms. tee aracters. ——Period of
softening. 305
IV. Of Melanosis.—lIt differs from the black matter of the
lungs.——Its distinctive characters.—lIts nature. 306
,

THE END.

es