Part second of A series of elementary lectures on the veterinary art [electronic resource] : wherein the anatomy, physiology and pathology of the horse, are essayed on the general principles of medical science

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.,Glasgow University Library

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PART SECOND

OF A

SERIES

OP

ELEMENTARY LECTURES

ON THE

VETERINARY ART:

WHEnEIN THE

ANATOMY, PHYSIOLOGY, AND PATHOLOGY

OF THE

HORSE,

ARE

ESSAYED ON THE GENERAL PRINCIPLES

OF

JWcUical Science.

WILLIAM PERCIVALL,

Member of the Royal College of Surgeons in London ; Licentiate of the
Society of' Apothecaries ; and late Veterinary Surgeon of the
Royal Artillery,

" Qui secat, sit anatoraes perilus, quia sub lioc medico ct artifice, omnia tuti>simc
et felicisslme peraguntar."— /VjArJcto ah Aquapendente.

" Morbornm qaoqne te causas et signa <\ocebo."~Virgil.

LONDON:

Publlsljed by

LONGMAN, HURST, REES, ORME, BROWN, AND GREEN,
Paternoster Row.

1824

vi CONTENTS.

LECTURE XXXI. P^g^^
On the Ligaments of Particular Joints-Articulations of the
Trunk-Docking-Articulatious .of the Fore Extremity-

Articulations of the Hind Extremity lotj to i»o

LECTURE XXXII.
On the Common Integuments-Cutis-Cuticle- Rete Muco-

sum— Physiology of the Skin— Hair i yo — ^ i »

LECTURE XXXTII.

On the Nose— Larynx— Muscles of the Larynx— Trachea-
Thyroid Glands— Diseases of the Air Passages— Catarrh; . 220 — 242

LECTURE XXXIV.

On Roaring 243 -261

LECTURE XXXV.
On the Viscera of the Thorax— Pleura— Diseases of the

Pleura — Hydrothorax — Adhesions 262 — 278

LECTURE XXXVI.

On the Lungs — Bronchial Glands • 279 — 288

LECTURE XXXVII.
On the Physiology of the Lungs— Production of Animal

Heat........... 289 — 309

LECTURE XXXVIII.
On the Diseases of the Lungs — Inflammation of the Lungs. . 310 — 333

LECTURE XXXIX.

On the Chronic Diseases of the Lungs — Bronchitis — Thick

Wind— Broken Wind 334 — 353

LECTURE XL.

On the Heart — Physiology of the Heart — Diseases of the
Heart 354 — 374

LECTURE XLI.

On the Mouth — Lips — Cheeks — Gums — Palate — Tongue —
Salivary Glands — Pharynx — Esophagus — Diseases of the
Mouth — Lampass — Stricture of the Esophagus 375 — 391

LECTURE XLII.

On the Viscera of the Abdomen — Peritoneum — Situation of
the Viscera of the Abdomen — Reflection of the Peritoneum
— Diseases of the Peritoneum 392 — 404

LECTURE XLIII.

On the Stomach — Intestines — Small Intestines — Large In-
testines 405 — 419

LECTURE XLIV.

On the Diseases of the Stomach — Diseases of the Intestines
—Enteritis , 420 — 433

CONTENTS. Vll

LECTURE XLV. Pages

' Diarrhoea— Colic— Calculi and other Concretions found in

the Intestines 434 to 450

LECTURE XLVL
'( On Worms — Bats — Lumbricus Teres — Ascaris — Taenia, , . . . . 451 — 467

LECTURE XLVII.
I On the Liver — Diseases of the Liver — Jaundice 468 — 483

LECTURE XLVIIL
< On the Spleen — Diseases of the Spleen — Pancreas 484 — 493

LECTURE XLIX.

> On Digestion — Mastication and Deglutition — Physiology of

the Stomach 494 — 508

LECTURE L.

! Physiology of the Stomach (continued) 509 — 521

LECTURE LI.

Physiology of the Intestines — Vomition , . . . , , . 522 — 538

LECTURE LII.

On Purgation and Purgative Medicines 539 — 559

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VETERINARY LECTURES.

LECTURE XXIV.

On the Teeth.

These instruments for the abscission and manduca-
tion of food, are remarkable in the horse, for number,
size, and durability. Unlike other parts,- at certain
periods of life, the teeth first produced are cast off and
replaced by others ; a phenomenon that has given rise
to the general division of them into temporary and
permanent sets ; of vi^hich I shall first examine the

Permanent Teeth.

At the age of five years a horse is said to have
'** a full mouth i. e. he is furnished with a complete
set of permanent teeth : in number, forty.

The teeth of the horse are so situated, in either jaw, ,
' that they are naturally distributed into three classes ;
1 two of which have received names from their respective
' offices in mastication, and the other an appellation in
allusion to its form : — the first comprises twelve dentes
incisores, or cutting teeth, six in each jaw ; the second,

PART H. B

2

Denies Incisores.

twenty-four denies molares, or grinding teeth, twelve in
each jaw; the third, four denies cuspidati vel canini, or
pointed or dog's teeth, two in each jaw : the teeth of
the anterior and posterior jaws correspond in number
and situation, and have a close resemblance to one
another.

In every tooth, of whatever class, we remark two
parts, one exterior to the gum, the other buried within
its alveolus or socket : to the former, for the conve-
nience of description, I shall give the name of hodi/,
and that of face to the wearing surface of it ; the latter,
I shall call the Toot, and the conical or pointed extre-
mity of it, the fang.

Denies Incisores.

The twelve * dentes incisores, or cutting teeth, or
nippers and gatherers, are regularly ranged, in parabolic
curves, in the lowermost parts of the jaws, and are at
once brought into view by the separation or eversion of
the lips. It will be remembered here, that, in describ-
ing the ossa maxillaria anteriora and the maxilla pos-

* In the Museum at the Veterinary College, there are two ante-
rior jaws, containing, each of theiii, eight incisores of ordinary
size ; in one, they are very irregularly placed ; in the odier, less so :
I apprehend that the corresponding jaws (for they were not pre-
served) had not nioire than the usual niumher. I haVe sittce seen
another specimen of the same overplus, in which the teeth, of their
natural size, were ranged in due order.— Mr. Cherry has a posterior
jaw in his possession, in which there are hut four incisores, not
of extraordinary magnitude; the alveolar prolongation altogether
is so narrow that there is not room for more : the anterior jaw
holds the complement of teeth, ariJ is consequently of dispropor-
tionate breadth, t have also by me, a firutilated specimen of the
same sprt.

Denies Incisor es.

3

tenor *, I pointed out the alveolar cavities proper to
these teeth — remarking that they were composed of
two laminae, intersected by transverse, thin, osseous
plates : these cavities are three-sided, about two inches
deep, grow pointed at bottom, and incline inwards ;
and are nicely fitted and filled by the roots of the
incisores.

In its general figure, an incisor approaches to that of
a bent cone, of which the face is the base and the root
the truncated apex ; but if its form be analysed, its
base will be found to be oval, its body circular, and its
root triangular ; and such is the variation of figure that
the face naturally undergoes through life, that it may
veritably be said to pass through several transformations.
Though the triangle of its root is nearly equilateral, and
: the sides of it are all fun-owed, they are so unlike, that,
by attention to them and the general inclination of the
■tooth, it is not difficult to assign to every incisor its
I proper place in the jaw.

In length an incisor of the posterior jaw measures
rabout 21 inches ; in breadth, the long axis of its face,
of an inch : the front teeth are a little longer than
I the middle, the middle than the lateral ; of the first,
; about eight lines appear above the gum ; of the second,
pseven lines ; of the third, six lines.

The body is whiter than the part below it, and is
isuperficially marked in front by one or two longitudinal
oirrows, according to the breadth of the tooth.

The face presents an oval-shaped pit in the centre,
iind two elliptical rims or borders around it, whose
»readth decreases with its depth, and whose depth, for a

* Lect. xxiii. Part I.
B 2

4

Denies Incisor es.

certain number of years, tears a given ratio to the age
of the horse. This pit is rendered conspicuous by a
lining, consisting of a thin scaly incrustation of black
earthy matter, and commonly contains a little dirt : it
has been likened to the eye of a bean, and thus has
obtained the appellations of mark, bean, &c. in speak-
ing of age. The rims around it are white and promi-
nent, and constitute the cutting or wearing edges of
the tooth : the outer one, that borders the face, parti-
cularly the inferior segment of it, projects a little beyond
the inner, and is indented, about its middle, by the
termination of the furrows along its body.

Internally the tooth is hollow ; but its body contains
an infundibulum, or funnel-like inlet, whose mouth is
the pit above noticed : independant of this, the cavity
altogether corresponds in shape and dimensions to the
tooth itself, and is entered by an opening at the extre-
xnity of the fang.

The anterior incisores are larger and more developed
than the posterior, and the semi -circular portion of jaw
that contains them in like ratio exceeds in dimensions
its opponent : on this account their outward edges com-
monly overshoot a little those of their fellows ; indeed
so much so in some horses, that their inward are ac-
tually opposed to the pits, instead of the edges of the
latler ; but in others they meet with precision ; and
now and then the reverse is seen. Their infundibula
also are larger and much deeper than those in the back
.teeth.

0 : In comparing the operation of these teeth to that of a
pair of nippers or scissars, the advantages of this con-
formation and collocation of them cannot fail im-
pressively to strike us ; and in duly estimating tlu

Denies Molarex. 6

force the jaws are capable of exerting, and bearing in
mind the sliding or scissar-like action of them, the
apparatus altogether must appear as effectual as it is
simple and admirable in its construction. By means
of his incisores, a horse nips the finest, nay the shortest
blades of grass ; by means of the same teeth, his hard
oaken crib is wantonly crumbled into dust : even iron
itself can scarce resist their gripe. In grazing, or in
browsing, these teeth seize the substance, but the di-
vision of it, which the animal effects by a twitch of the
head, is rather an act of rupture than one of dental
section — vellet dentibus herbas — and this vellication, in
taking food, is equally remarkable in the stable, when!
a horse is eating his rack -meat, even though it is there
ready cut for him. In fact, these teeth appear rather to
demand the name of dentes vellentes than dentes inci-
sores; and they who named them nippers and gatherers,
have left us reason to conclude, that they, at least, had
paid attention to their economy ; for, in feeding upon
pulse or grain, the incisores do little more than (aided
by the lips) gather up the seed, in order that it may be
passed on by the tongue to the molares or grinders of it.

Dentes Molares.

The molares or grinding teeth, twenty -four in num-
ber, are implanted in rows into the sides of the jaws.
Six upon each side are encased in the alveolar cavities
of the OS maxillare superius, at the space of about four
inches from the incisores ; the twelve others, their op-
ponents, are fixed within those of the maxilla inferior,
somewhat nearer to the lower teeth*.

* This appears to be for the purpose of maintaining that due

6 Denies Molares.

A dens molaris is equal in magnitude to four or five
incisores ; it varies in length from 21 to 3 inches ; in
breadth, in the anterior jaw, from 1 to U ; in the pos-
terior, they are little more than half as broad : they
are therefore not likely to be mistaken for one another.
. The figure of an anterior molaris is that of an oblong
quadrangle, slightly incurvated in order to accommo-
date it to the contour of the jaw: the posterior,
though similar at first sight, is straight, and flattened
from being so much less in breadth ; so that the
quadrangle, still an oblong one, has its sides more
unequal. The first and last molares of either jaw, are
known at once by being triangular : the extended
angles of the four inferior are directed downwards ;
those of the last or superior, upwards. Indeed these
four teeth, instead of being inclined inwards in their
sockets, are laterally curved ; so that the upper ones
of the anterior jaw press, with their roots, against the
floor of the maxillary sinuses ; and those of the pos-
terior jaw run upwards into its branches. The chan-
nels along its sides strike us with a notion that a
molaris was originally composed of four incisores, now
become one and the same tooth by inter-union of sub-
stance ; in the composition of the lateral teeth, indeed,
five. nippers seem to have been embodied.

The conspicuous objects upon the face of a molar
tooth are two transverse ridges, with transverse furrows
between them, and tioo pits : those that are of a trian-
gular figure have an additional eminence, jutting from
the point of the extended angle. The pits, like those

relative position which must otherwise have been disturbed by the
projection of the anterior jaw.

Denies Molares. 7

t)f the incisores, are iucrusted with darjc or black
earthy lamella, and assume the appearance and take
the name of marks ; they are not of long continuance
however, nor do they (that I am aware) disappear at
any regular or stated times ; and consequently alFord
us no useful information concerning age.

The tooth is hollow within, and imperfectly ,di^
vided into chambers by two infundibula, which extend
through it and tei'minate within the cavities of the
roots.

From the alveolar portion of it, which is truncated,
after a time, proceed the fangs ; which are short, conical
tubes, flattened at their sides, and open at their ends.
They are three in number: — two outer, and one inner;
and tlie broad side of the inner one is opposed to the
sharp angles of the two outer ; in which manner the
quadrangular figure of the tooth is still preserved*.
But a posterior molaris has but two fangs ; and they
. are placed on a line with each other.

The molar teeth, arranged in their sockets, present
upon each side of either jaw, a serrated wearing sur-
face of more than half a foot in extent : the faces of
the anterior incline from without inwards, those of the
posterior slope in the opposite direction ; so that, when
in apposition, they meet upon a level with one another.
The anterior jaw is about an inch and a half wider
than the posterior ; and, when the mouth is shut, the
anterior molares, all but the last, laterally overhang
about half an inch their opponents ; but inwardly, the
posterior teeth project a little beyond them. When the

* The first and last anterior molares often have but two fangs :
A^hen three are present, they are disposed triangularly.

8 Denies Molares.

jaws are approximated, therefore, the slanting ridges of
one tooth are obliquely received into the sloping furrows
of its fellow, to which they are adapted ; by this dis-
position of them not only is the surface of manducation
amplified, but the powers of contusion and trituration
greatly augmented in efficiency : but in order fully to
comprehend and appreciate the construction and opera-
tion of this remarkable apparatus, it will be necessary
to understand the action of the posterior jaw.

By the depression of this bone, downwards and
backwards, the mouth is opened ; by a contrary motion
of it, it is shut : of the muscles attached to it for these
purposes, those are by far the most powerful that
elevate the jaw. In addition to these movements, the
jaw can be drawn to one side, in a limited degree, by
the unopposed contraction of the muscles of the other
side ;■ and by alternating the action of these muscles
with that of their antagonists, it may be slid first on
one side and then on the other : this is what is meant
by the lateral or grinding motion of the jaws.

Here, then, are four jagged surfaces of impenetrable
hardness, opposed to four others equally hard and
uneven, having the power of shutting into one another
hot only with great force, but with great exactitude,
and of sliding laterally upon and rubbing against one
another when in apposition. Seeing this, are we to
feel surprised that the hardest pulse are contused, that
the smallest seeds are crushed, and that nothing, in
fact, under the denomination of provender, be it ever so
hard or ever so small, can escape the operation of this
admirable piece of animal mechanism ! In no animal
is this rotatory or grinding motion of the jaw better
demonstrated than in the ruminant ; in which, this bone.

Denies Cuspidatl, 9

<) its sphere of rotation, appears to describe so many
irregular circles ; and indeed, this is the kind, though
not the degree, of action that it has in the horse, during
u liich the molares, (according to the import of their
name,) like so many millstones, bruise, break down,
comminute, and triturate whatever substance may be
interposed ; in short, so demolish it that the juices of
the stomach may readily soak through and dissolve it.

Denies Cuspidati.

The dentes cuspidati vel canini, or tusks, are four in
number : — two in each jaw *.

■ They arise out of conical sockets, in isolated stations
in the jaws, between the last molares and lateral in-
cisores, about an inch from the latter in the posterior,
about an inch and a half from them in the anterior jaw ;
but this space increases with age f.

In figure, the tusk, when first cut, is a cone, slightly
incurvated, whose base is sunk in the jaw ; afterwards,
however, it becomes conical at either end, and the
bases of these cones are united at the gum. When
fully evolved, the tusk projects nearly or quite an inch
from its socket, and terminates in a curved ;p.ointed ex-
tremity. : :

During its growth^generally until the sixth year,
about which time it is. completely developed — the in-

* I have a posterior jaw that contains three tusks : two, on the
near side, spring from separate soclcets.

t From the fact of the distance between these tee,th , growing
greater with age, I was led to think that an useful criterion might
be made of it; but I found so much variety that I was compelled
to relinquish it for this simple conclusion: — that the inter-space

xtends, hut not regularly, with the accession of years.

10 Dentis Cuspidati.

ward part of it is slightly concave and fluted : it has
two longitudinal furrows along it that meet at its point
like the two legs of a triangle, leaving a conical emi-
nence between them ; but as age proceeds, the inter-
vening portion of tooth swells out from continued ac-
cretion, and the part gradually assumes a convexity ;
indeed so much does the tusk alter its form by the ele-
ventli or twelfth year that the originally pointed cone
is worn down to a regular cylinder. ■

So long as the tusk lies hidden in its socket, it has
no fang — it consists simply of a thin thimble-like shell
of hard substance ; but as the body emerges the root
also elongates, and a fang forms, which is only per-
fected when the tooth itself has attained its greatest
evolution in the mouth. At this period the tusk is
hollow throughout, and is perforated at its root by a
small foramen ; but as years advance the cavity gradu-
ally fills up, and in old horses we can percieve no re-
mains of it.

It is said that mares have no tusks. So far as my
examinations have gone I have not found any jaws
without the rudiments or fac-similies of them ; though
they are not commonly seen but during or past the
middle ages of life : whether all females that live to old
age cut them prior to death, I am not certain— I am
disposed to think that they do*.

These teeth are so set in the jaws, that their points
cross and not meet one another. The posterior are
longer and more luxuriant than the anterior. It ap-
pears to me, that tusks were given to the horse, in

* " There is an hermaphrodite horse, twenty-six years of age, kept
at this school: (Berlin:) it is similar to tliat at Vienna, and has
tushes like a stallion." Mr. Sewell's Report.

Temporary Teeth. 11

ivhom they are not so formidable as in other animals, as
iveapons of defence ; he has an advantage however over
most of them in being able to combat with an adversary
oehind as well as before : his hoofs enable him to re-
pulse a foe in pursuit, his tusks seem designed for
iittack.

Temporary Teeth.

From the age of ten months to that of two years
und a half, the horse has a certain number of teeth,
i denominated his sucking, milk, shedding, or temporary
•;et. They are twenty-four in number : — consisting of
twelve incisores, six in each jaw ; and twelve molares,
ithree upon each side, above and below*.

The temporary incisores are readily known, either
in situ or out of their sockets, from the permanent,
m being smaller and whiter, in having no furrows
.ipon their bodies, in having necks or contractions
where the root joins the body, and in having slender
pointed fangs. The molares in the young animal are
smaller and whiter, and have sharper eminences upon
their faces.

Those denticular excrescences called wolves' teeth,
notwithstanding they are so generally met with, I re-
gard as lusus naturtz — as constituting no part of a regu-
lar or full set of teeth. They spring out beside and an-
terior to the first molares, in both jaws, with which
:hey are conunonly cast off, never to be replaced.

The temporary teeth are shed in succession to make
•oom for the permanent : as the latter grow in sockets

* The eight upper grinders and the tusks do not make their ap-
)carance within thiis period, and are not shed ; no more are the
"ourth molares, but they exist with the temporary set.

12 Strvcture of the Teeth.

contiguous to them, these, by absorption of their fangs,
continue to give place, and at length drop out. They
are not pushed out, as the vulgar will have it ; but that
pressure has an influence upon the absorbing process
is demonstrated by the aspect of their ulcerated bases —
more particularly of those of the molares — which bear
the exact impressions of the faces of the forthcoming
teeth.

Structure of the Teeth.

Two hard substances, distinct from each other in
aspect and nature, enter into the formation of the tooth :
one, enamel, is peculiar to it; the other, in conse-
quence of putting on the appearance of, is generally
described as, bone.

The Enamel. In examining an incisor, we find
that the body of it is whiter, smoother, and harder
than any other part, and that it has a polish upon its
surface as if, being exterior to the gum, it were de-
signed for ornament : these appearances it owes to a
coating of enamel. So impenetrably hard is this sub-
stance that files and saws make but little impression
upon it, and it is fractured but with considerable force :
its fragments exhibit a fibrous composition, and its
fibres proceed, like radii, from the body of the tooth
towards the wearing surface of it. To many chemical
agents however it opposes but a faint resistance : by
the mineral acids, and by some of the vegetable indeed,
i^ is more or less quickly corroded— the nitric and mu-
riatic acids dissolve it, sulphuric exerts a slower action
upon it, and concentrated distilled vinegar gradually
roughens and erodes it. The essential difference be-
tween enamel and the bony substance is, that the for-

Structure of the Teeth. 13

liner has no animal or organizable matter in its compo-
sition : it is believed to be a secretion, originally in a

) fluid or semi-fluid state, which by chiystalization as-
sumes its characteristic solidity and hardness. 'If - a
tooth be exposed to the action of fire, the bony part

inims black from destruction of its animal ingredient,
but the enamel preserves, almost unsullied, its former
whiteness : by this simple experiment, many very neat
preparations may be made ; and it is of the greatest
service in this stage of our inquiry, from the distinct
and beautiful manner in which it displays the distribu-
tion of this substance within the body of the tooth.

Of an incisor, the enamel completely coats the body,
and is consequently more abundant outwardly than in-
wardly ; from which it passes upon the face, where it
is reflected inwards, and deeply sunk in the shape of
a funnel, having an elliptical mouth, into the body of
the tooth, and thus forms the infundibulum or pit ; but
as soon as the face is worn a little, (which speedily
follows the evolution of the tooth,) the reflected portion,
being disunited, has the appearance of a separate
layer, and then the elliptical edge of it forms the inner
rim: the interspace, which is greater below than
above, is filled up with bony matter.

About a molaris, the disposition of the enamel, while
it evinces much regularity and beauty in appearance,
may carry with it a notion of complication in descrip-
tion, which it seems difficult to divest it of. The body,
like that of an incisor, is externally defended by ena-
mel ; but unless the tooth be examined when fresh cut,
it is commonly found to be encased with a thin lamen
of a substance of an earthy nature, that gives that un-
wholesome— yellow or black — aspect to it which it

14 Structure of the Teeth.

evidently has when contrasted with the other teeth-
immediately underneath this case, then, which I re-
gard as adventitious and extraneous, and which often
in places chips off and exposes it, is the enamel. But,
in place of there being one inner lamen or reflection of
it, there are two— the molaris having two infundibula—
from which two inner rims are formed by wear, whose
circumvolutions upon the face together correspond to
those of the outer rim : in this manner the enamel pene-
trates the very heart of the tooth, and defends it to the
last against the effects of mordication and attrition. It
follows, therefore, that in the new tooth we find the
eminences of the wearing surface completely coated
with enamel ; but its depressions without any.

Of the tusk, the body is completely encased in enamel :
it is not so thick upon the inward or fluted part as else-
where, and grows thin and imperceptibly vanishes
upon the base.

Bone of the Tooth. It is mostly an unthankful
undertaking to meddle with or alter names, though ad-
mitted to be inappropriate, that established usage has
once confirmed ; and this appears to be the reason
why the one above still keeps its ground with most
teachers and writers of the present day. What is called
the bo7ie of the tooth is unlike in its origin the bories
truly so named, unlike in its mode of subsistence and
regeneration, in its properties, in fact in all but its che-
mical composition, and according to some, in that *.
Indeed, though it is resolvable into a gelatinous matter

* Some continental chemists aver, that in addition to the eartiiy
and saline matters found in bones, this substance contains fluoric
acid, in combination with lime.

Structure of the Teeth. 15

and an earthy, which is chiefly phosphate of lime, there
is an additional quantity of the latter in its composition,
and that is more closely compacted ; to which we may
apparently ascribe the characteristic density and hard-
ness of it. A^ain, although a substance something
like cartilage is left, which has the form of the original
tooth, when it has been deprived of its earthy compo-
nents by acids, it was never, like bone in its primitive
state, cartilage ; nor does it contain any medulla or
cancellated structure. It is covered exteriorly by peri-
osteum, through the medium of which it has a firm ad-
herence to the sockets and gum, but, though like bone
it receives a tincture when an animal has been fed with
madder, it is not supplied with blood in the same man-
ner; for its vessels, which cannot be traced further
than the surface, are derived from the interior — from
the pulp. Internally it is hollow ; and the shape and
size of this — the cavity of the tooth, bear an analogy to
those of the tooth itself.

Within this cavity, contained in a membrane of a
periosteal nature, denominated the membrane of the
tooth, is the pulp, or what is regarded by the vulgar as
the nerve of the tooth : it is a gelatinous substance
if correspondent bulk and form to the tooth that con-
tains it. In the molares there are" several pulps from
which processes are sent dowm into the fangs, and
r very one of them is inclosed in a membrane of its
own ; but an incisor, or a tusk, has but one. The
l)ulp, being that part from which the bony substance
derives its vitality, is amply furnished with blood-vessels
mid nerves, and these make their entrance at the foramen
in the fang ; hence it is that in very old horses, in whom
these cavities are filled and obliterated, and the pulps

16 ISbrmaiion of the Teelh.

have shrunk or been absorbed, we occasionally find
teeth carious and disposed to fall out. Absorbents witli-
out a doubt exist in them ; but our means are inade-
quate to such minute investigations.

Some foreign veterinary anatomists describe a third
substance, which they call the corticale, cement, or sub-
stantia cornea: Girard thus alludes to it — " The corti-
cal substance which is met with in all herbivorous ani-
mals, and which the teeth of the hog show vestiges of ,
forms a sort of bark ; it incrusts upon and envelopes the
body of every tooth, and is admitted to a considerable
depth into its pit*." If by this be meant the brittle in-
crustation of a grey, yellow, sometimes black hue, only
found upon teeth that have left their sockets, I regard
it as extraneous and adventitious : it is often met witli
upon the molares, seldom upon the incisores or tusks,
unless it be late in life ; how far it approaches in its. com-
position to tartar I am not just now prepared to state.
In all teeth, the infundibulum, being a convenient place
of lodgment, contains it.

Formation of the Teeth.

About the third or fourth month of foetal being, the
rudiments of the future teeth are discoverable in the
alveolar channels of the jaws. They are so many
pulpy masses, of the consistence and nature of jelly, in
size and form, with the exception of the fangs, like the
teeth of which they may be regarded as the nidi : they
have membranous capsules, and are penetrated by nen cs
and blood-vessels. Soon after the appearance of this
substance, specks like osseous matter may be detected
in that part of it which corresponds to the cutting or

* Amtomie Vetirinaire. p. 158. torn. I. edit. II.

Formation of the Teeth. 17

wearing edge of the tooth ; these earthy particles gra-
(hially spread, coalesce, and form, by their union, a
thin, brittle, bone-like case, denominated the shell of
the tooth, in which the pulpy matter is inclosed. As
the process of conversion goes on, and the shell grows
thick and strong, the pulp within, compressed on every

ide, proportionably diminishes from absorption ; and
us this process is continued through life, until the cavity
of the tooth is blocked up and obliterated, from con-
solidation of it, the pulp still laecessarily shrinks, and
ultimately disappears. The shell of the body and root
of the tooth is completed before the fang is begun.
In the pulp of an incisor, two or three minute opaque

pots first appear in the part to be converted into the
lutward cutting edge, which, by accretion, compose a
fhin flexible lamen of bone-like matter, similar in shape

0 th^aring of a human nail ; and this is reflected upon
( self to form one side of the infundibulum : in like man-
ler, but later, the inward rims are produced, which,
>y their union with the former, constitute the masti-
atory surface.

In the pulps of a molaris the points of ossification cor-
espond in number to the eminences upon its face, they
)eing the parts that first undergo the change : in the
ourse of conversion they consist of so many bony caps,
lie outer laminae of which afterwards constitute the
)Uter wall ; the inner unite and compose the infundibula,
md from them aliform processes shoot and form the
liambers.

The enamel is secreted from the internal surface of the
neniljrane originally covering the pulp. It is ejected in

1 fluid state upon the shell of the tooth, and first of all

PART 11. c

18 Formation of the Teeth.

upon its face, and acquires its subsequent flinty hard-
ness and imperishableness, it is supposed, by crystalli-
zation. A tooth is completly enamelled prior to its leav-
ing its alveolus.

The permanent tooth owes its origin to the pulp of that
which it is destined to fill the place of. A vesicular and
vascular substance, soon after the formation of the pulp
of the temporary tooth, is seen growing from it within
the same socket ; but as this increases in size, a separate
socket is constructed around it, which would cut off
all communication with its matrix — the original pulp,
were it not for an elongation of membrane, called the
gtibernaculum, that still connects the one with the other.
So early is this provision made, that if the jaw be
examined but a few weeks after birth, there vnW be
found the pulps of the front permanent incisores, in
sockets of their own, seated above those of the corre-
sponding temporary teeth ; the fourth pemanent molaris
nearly completed ; and the fifth already much advanced
in the process of conversion. Along the roots of the
temporary molares, attached to them by several guber-
nacula, is a membrano-gelatinous substance, which is
to be regarded as the pulps of the future teeth, as yet
not distinguishable from one another for want of bony
partitions in the channels containing them.

In speaking of the fangs, I said that they were not
formed until the bodies had left their sockets ; nor are
they completed until the tooth is fully evolved. We are
not to suppose however that this is the case so soon as
it has shot to a certain length in the mouth ; for, after
this, not only does it undergo internal consolidation and
consequent obliteration of its cavity, but it continues

Formation of the Teeth. 19

to grow at its root and develope fresh parts at the gum,
and would evince it by its length, were there not op-
posed to this — which I would call its — after-growth, the
attrition and consequent destruction of the face. It has
already been shown that the enamel upon the fresh cut
tooth is continuous from the wall, upon the face, to the
infundibulum, and that the rims are produced by the
wearing off of the reflected portion of it ; but as the
further demonstration of this important fact forms the
basis of a knowledge of age after a certain period of
life, I shall postpone it to the ensuing lecture.

In order to make room for the three additional supe-
rior molares, and to admit of some enlargement of the
sockets for the succession of the three permanent
inferior molares, which are somewhat larger than the
temporary, the jaws, for a certain term of years, receive
considerable accretion. At birth, that part which holds
the grinders measures but 3^ inches in length, at four
years of age the same part measures eight ; for it now
contains three new teeth, in addition to three others
that have become permanent. But the jaws, and more
particularly the posterior, not only greatly increase in
length, but undergo also, in the course of growth, some
alteration in shape : before the incisores are put forth,
the lower jaw is nearly rectilinear along its side ; while
these teeth are cutting, it elongates, its body expands,
and a contracted part, or cervix, is evolved. A further
deviation of form is perceptible in the decline of age :
the alveolar projections grow scanty and straight, giving
the incisores the appearance of increased length, and
a greater inclination outwards or downwards ; their
semi-circular contour is also less striking ; indeed the
alveoli themselves in the vale of years show a disposition

c 2

20 Diseases of the Teeth.

to grow up, and hold the shrank and pointed roots of
the teeth with less and less stability and firmness.

Diseases of the Teeth.

This is a subject upon which I have but little to offer.
The horse appears to be but very rarely afflicted with
those distressing pains, called tooth-ache, by which
the lives of many human beings are embittered ; and a
most fortunate circumstance it is for him ; for, if he
were, I know of no signs by which he could with cer-
tainty direct our attention to the seat of pain, nor of
any means we have of eradicating it by extraction.
Still I have several preparations now before me, the in-
spection of which leaves little doubt in my mind, that
the animals from whom they were taken were the
subjects of tooth-ache, and, if I may venture an opinion
from post mortem appearances, of a most acute and ir-
remediable description*.

The most interesting case of this kind that has come
to my knowledge, is the subjoined; with the particulars
of which I have kindly been favoured by Mr. Cherry,
V. S. Clapham.

A horse, the property of government, became a patient
of Mr. Cherry's for a copious efflux of foetid discolored
pus from the near nostril, unaccompanied with any sub-

* One is a permanent molaris, whose exterior presents masses of
adventitious bone, and whose interior is black, ragged, and in part
destroyed by caries : its fangs have mouldered away.

Two others are lower jaws, having porous brittle exostoses upon
their sides, that form spacious cavities, and communicate with the
third and fourth molares : through a hole in one of them pus, it
would appea;r, was discharged during life. I should imagine that
these cases originated in external injury.

Diseases of' the Teeth. 21

maxillary tumor or apparent ulceration of the pituatury
membrane. For two or three months the case was
treated as glanders ; but no steps having been gained
towards amelioration, a consultation was held, and the
horse eventually shot. — On examination of the head, the
third molaris was discovered in part eroded by caries :
about one -third of its fang was deficient, and the re-
mainder rotten. The tooth was loose in consequence of
the formation of an abscess within its alveolus, which
had established a free vent into the contiguous chamber
of the nose. The antrum was partly blocked by internal
osseous deposition.

Now, had the molar teeth been examined in this case,
prior to death, it would unquestionably have led, from
the circumstance of one being loose, to a shrewd
suspicion of the nature of it, and might have been the
cause of saving a life valuable to the service. It
behoves the practitioner, therefore, to be on his guard
in pronouncing the sentence of death in such affections
as these, which are all huddled together at the present
day and styled " chronic glanders :" an indefinite and ill-
understood malady, and one under which the above case
must have for ever remained buried in oblivion, had not
the most laudable of motives prompted Mr. Cheery
to inspect the parts post mortem.

LECTURE XXV.

On Age.

TThE periodical regularity observed in shedding the
teeth of the horse, has from very early times attracted
the notice of his keeper as a criterion of age ; and so
unerring a test is it that I do not hesitate to say, that
it is evidence on w^hich we ought to rely in preference
to any other when the animal has not been bred imme-
diately under our own eye. Art indeed, the ever ready
instrument of deception, has exercised its ingenuity to
accelerate the process, and thus sacrifice the immature
frame to destructive usage ; but so uniform is Nature
in these operations, that no horseman who has paid
attention to the subject can be imposed on, in this man-
ner, in any but horses that have been foaled out of due
season. It therefore reflects no little discredit upon a
professional man if he be uninformed in this department
of his duty ; for he is thereby not only incompetent to
form a correct diagnosis or prognosis in many diseases,
but is absolutely unqualified to estimate the physical
powers of the animal 5 and consequently to duly appre-
ciate or treat him in a state of health.

On the completion of the fifth year the mouth is

Shedding Temporary ^ Cutting Permanent Teeth. 23

furnished with a full set of teeth ; prior to which we
assign age according to the different stages of the shed-
ding process : but subsequent to the fifth year, which
may be regarded as an epoch in age, we form our opinion
by the appearances that the teeth assume in the course
of a series of changes, which they, with more or less
regularity, from year to year undergo. In accord-
ance with these facts, I shall consider age under two
heads : — the shedding of the temporary t6eth ; and the
changes to which the permanent are naturally subject for
the remainder of life.

On the Sheddi?ig of' the Temporary and the Cutting of'
the Permanent Teeth.

The permanent teeth, it has been shewn, arise in
sockets of their own, while the temporary, in order to
make room for them, first lose their fangs, and ulti-
mately a part of their bodies : thus, while the former
are springing up in all the vigour of growth, the latter
have their vitality sapped by the contraction and disap-
pearance of the pulp, and lose their hold and fall out
from absoi-ption of the root. The appearance of the
shed tooth, although, I repeat, it is not pushed out,
warrants our belief that the process of absorption is
much promoted by pressure ; for the internal part of it
is the exact counterpart of the face of the new tooth,
as if the one had been long and forcibly impressed by
the other.

In ascertaining age, the molares, for two reasons, are
never looked at : — in the first place, they are with dif-
ficulty examined, or even numbered ; and in the second,
they afford no information but what is more readily and
more correctly obtained from the aspect of the incisores.

24 On the Shedding of the Temporary and

Indeed it is but seldom that we examine at the anterior
teeth, and when we do, it is by way of corroborative
evidence ; so that, in fact, our judgment mainly rests,
up to the age of five, upon the number and class of the
posterior incisores, and aftei' that period, upon the
changes they have undergone.

By common consent, in this countiy, all horses' ages
are reckoned from the Jirst of May, without any re-
ference to the day or even the month in which they
were foaled, so that it be within that year ; but I believe
that as many mares bring forth in June as in May, and
that of those that are thorough -bred the majority foal in
February ; and some as early as Januaiy : let this be as it
may, however, it is of considerable moment to the sport-
ing world that the ages of all horses, of whatever descrip-
tion, should be dated from the same period ; and May
perhaps, under all considerations, is happily chosen *.
In being called on to affix this precise date however, we
are now and then involved in some uncertainty, when
we meet with horses that have been foaled either very
early or very late in the year : these anomalies have
given rise to the expressions " a forward mouth," and
" a backward mouth," or, what are synonimous, " an
early foal," and " a late foal ;" and indeed in some

* On the turf, it has always been a rule, that the age of a racer
shall be reckoned from the May of the year in which he was
dropped, wthout any inquiry whatever into the season, month, or
day of foaling ; so that the produce in January are actually four
months older than they appear, from the ages affixed to them, in the
Calendar: and these are called eoWy foals; whereas those foaled
in March are denominated late. But the breeders take care not to
be too nice in their reckonhigs, lest many mares produce in Decem-
ber; and the ages of their offspring be post-dated in place of anti-
dated.

the Cutting of the Permanent Teeth. 25

c ases so remote is the real day of production from the
presumed or nominal one, that it is extremely perplex-
ing, or even impossible, to decide whether the animal
may have been a late foal of one year, or an early one
if that ensuing.

A foal at birth is in the act of cutting twelve molares—
three upon each side of each jaw : the middle teeth are
generally more developed than the lowermost, these than
the uppennost ; indeed the faces of the last-mentioned
lour are often still clothed by the gums. Though at this
time there is no incisor apparent, they all lie buried,
ready-formed excepting their fangs, within their respec-
tive alveoli, at depths correspondent to the order in
which they are to make their exit. The teeth of the
anterior maxilla are commonly cut some short time
before their fellows of the posterior : a remark that ap-
plies to the molares as well as the incisores *.

About the expiration of the first, or in the course of
the second week — seldom so late as the third — the front
incisores make their appearance ; and during the fourth
or fifth week, they are succeeded by the middle teeth f.

Generally in the course of the sixth month, now and
then not before the tenth, the lateral teeth are put forth ;
and then the animal has his complement of incisores,
and is said to have his " colts mouth." It is about this
age that the foal, but sparingly supplied with milk from
its dam, betakes itself to gather its own subsistence—

* Those horses in which we meet with the contrary have had,
most of them, their posterior temporary incisores knocked out ; and
thereby the appearance of the permanent rendered precocious.

t About this time small foramina, containing the rudiments of
I tie tusks, arc discoverable in the dried bone, immediately above the
l>romincnccs of the lateral incisores.

26 On the Shedding of the Temporary and

now that Nature has furnished its mouth with a com-
plete set of gatherers and nippers for the purpose.

From this period until the animal has attained his
first year, no additional teeth shoot from the jaw :
then, a few weeks earlier or later, his first horse or
permanent teeth, the fourth molares, show themselves.

'in the interval of the first and second years, the fifth
molares appear ; and the fourth gain their proper level
in the jaw.

Between the second and third years, the front per-
manent incisores displace the temporary ; and at the
same time, the first temporary molares are shed, and
replaced by the first permanent : ,the outward borders or
cutting edges of these and the other incisores, cut the
gum about six weeks, or two months, before the inward
appear.

Between the third and fourth years, the middle tem-
porary incisores are cast off, and succeeded by the
permanent ; and the second temporaiy molares give
place to the permanent.

In the interval of the fourth and fifth years, the
lateral permanent incisores spring from their sockets, the
sixth and last permanent molares make their exit, the
third and last temporary molares * are displaced by the
third permanent, and the tusks peep from the gums :
so that by the fifth year, as was heretofore stated, a
horsfe is furnished with a . complete set of permanent
teeth.

The respective half-years are commonly set down as
the dates when these changes take place ; but there is
so much variety in this particular that I have chosen

* Not infrequently this tooth is cut about the same time that the
second temporary grinder is shed, or a little while after it.

the Culting of the Permanent Teeth. 27

rather to ascribe them to the intervals between the
month of May of one year and that of the year en-
suing. It may be asked here, if there be so great va-
riety, how can Nature be said to be periodically regular
in these operations ? So far as regards the year this is
so true that I have never seen, nor even suspected, a
deviation from it ; and if all horses were foaled in May
there would be little or no ambiguity about age : but
this is not the case with children ; though most of them
begin to shed their teeth about seven years of age, ano-
malies are by no means uncommon ; and instances are
on record in which some of the temporary set have re-
mained in the head to the adult or even senile period of
life. As it is — with the anomalous mouths that we oc-
casionally meet, owing to the casualties of breeding,
attendant and chiefly consequent, upon our. interference
with the habits of the horse in a state of nature — we
but rarely, prior to the age of five, hesitate to pronounce
the year of the animal's production ; and this being
ascertained, his age presumptive — the postulatum, is
thence deduced : indeed, as we always reckon from the
first of May, the calculation may be nominally pursued
to the very day.

It is the common practice of our breeders of horses to
knock or punch out their temporary incisive teeth with
a view of prematurely developing the permanent ; but,
though it certainly appears to accelerate the process,
their artifices are unavailing, so far as they are exe-
cuted for the purpose of deception or fraud, with one
who has paid practical attention to the subject; for it
is not in the power of art to make a horse, foaled in the
regular breeding season, appear to an experienced eye
one year older or younger than he really is ; and conse-

28 On the Changes which the Teeth undergo.

quently all its ingenuity and effort amount to nothing-
but vain and cruel experiment. It is more particularly
between the third and fourth, and fourth and fifth years,
that this artifice is practised ; it being an affair of great
pecuniary consideration with the breeder to sell his
three-year-olds for four-year-olds, or them, the follow-
ing year, for five-year-olds ; or if the breeder dispose
of them to the dealer before this age, the latter seldom
makes his transfer to the public, if he keep them long;,
without exercising his craft for similar ends.

Dentition is generally attended with more or less
turgidity and tenderness of the gums, but seldom to a
degree to be productive of pain or inconvenience : when
the soft palate, during the cutting of some of the an-
terior incisores, is the part principally affected, the
horse is said to have the lampas*.

On the Changes which the Teeth undergo.

No sooner have the teeth arrived at their proper level
in the mouth than certain natural changes commence,
by the careful observation of which we may, with con-
siderable exactitude, prosecute the animal's age to an
advanced stage of life.

A fresh-cut tooth has, projecting from the outward
part of its face, a sharp, waving border of enamel, from
which the surface slopes in a shelving manner inwards ;
there being on the other side no equally prominent
boundary : the pit, which is in consequence defective
upon the inward side, is open, deep, and as yet un-
stamed and free from extraneous matter. In the course
of the ensuing year, the inward border grows upon a

information on this" subject, vide Lect. <' On the MotUh.'

On the Changes wMch the Teeth undergo. 29

level with the outward, and takes its share of attrition ;
-and now, first from the outward edge, then from it, the
doubling of enamel is erased, and two elliptical ena-
melled rims become apparent, one of which borders the
lace, the other margins the pit : the pit itself is com-
pletely walled in, and soon becomes more or less black-
ened by some earthy incrustation, or any dirt or ali-
mentary matter that may collect within it. In the
course of the third year from the eruption of the tooth,
the rims are worn down smooth, and the pit, both from
attrition and the process of consolidation, (which is
always gradually going on in the interior of the tooth,)
becomes contracted, and almost closed or, to use the
common expression, JiUed up, leaving but a small de-
pression from which the mark is erased*. That the
infundibulum does not close and disappear either from
wear or internal deposition alone, but from both these
causes, is evident, I think, from examination of the
teeth ; for, in regard to the first, the bare inspection of
them in situ will convince one that they have shot frorn
their sockets without having proportionately augmented
in length ; and, in reference to the last, if the teeth be
removed, they will not only be found to have grown
heavier, but actually thicker in substance, and some-
what altered in shape. This piece of knowledge ought
to set us right about the appearance and disappearance
of the marks +, and enable us to explain the origin of
those anomalous mouths that give rise to so much alter-

* This depression is still surrounded by a prominent lip of ena
mel, which, in the course of years, gradually contracts, approaches
the inward border of the face, grows round, becomes less distinct,
and at length vanishes altogether.

t By which I mean the bean, or black incrustation lining the pit.

30 On the Changes which the Teeth undergo.

cation and cavilling among those who are totally unin-
formed on the subject. If it exclusively depended
upon natural causes, that timely imiformity so uni-
versally displayed where they are not interfered with,
would doubtlessly shew itself here ; but as the change
is one produced by wear, surely we ought not to feel
surprised at the many departures from the regular pro-
cess, or be at a loss to account for them! But, the
truth is, that the number of anomalies is by no means
so great as it is too generally thought and represented
to be, and that this discouraging report has had its
origin in the little attention that has hitherto been paid
by us to the subject.

In the course of the fourth, fifth, and sixth years,
the front incisores undergo and complete these changes ;
during the fifth, sixth, and seventh, the middle teeth ;
and during the sixth, seventh, and eighth, the lateral
teeth : so that from the fifth to the ninth year, the for-
mation and rasure of the rims, and consequent levelling
and planing of the face, and the contraction and closure
of the pit, and subsequent disappearance of the mark,
are our criteria of age. To illustrate this by example — of
a horse five years old *, the face of the front incisor is
level and smooth, a depression is visible in the site of
the pit, but the mark is effaced from it ; the middle in-
cisor has completely formed rims, and they are level
with one another, but its pit, though not so broad or
deep as that in the lateral, still remains — in other
words, it exhibits precisely the same aspect that the
front did in the foregoing year ; but of the lateral tootli

* Which he is from the completion of the fifth year until tlie re-
turn of the first of May.

On the Changes which the Teeth undergo. 31

the inward rim is still imperfect, the outward one wav-
ing or irregular, and the pit broad and deep : in fact,
its features altogether resemble those the face of the
middle had during the fourth year.

Even the temporary incisores proceed through these
changes, and with more regularity, though they require
much less time to perfect them, than the permanent.
The front nippers of the foal are worn smooth by the
time the lateral are developed — about the tenth month ;
the middle become so about the twelfth, and the lateral
about the fifteenth month ; at the age of two years, all
the marks are effaced. There is this advantage in bear-
ing in mind these few particulars relative to the tem-
porary teeth — that we may not commit our judgment
into the hands of the breeder by mistaking a yearling
for a two-year-old, or vice versd : this, to some, may
appear infeasible or ridiculous ; but I have heard such
erroneous opinions given by those who have contented
themselves with a sui^ey of the exterior, when the
animal has been much above or below the ordinary
statue of foals of the same year.

Although this is the common course of the first
series of changes in the aspect of the posterior inci-
sores, instances of deviation from it are by no means
wanting : at the same time I wish it to be understood,
that they are not so numerous as we have been led to
believe, and that by attention and skilful examinations
we shall often be enabled to detect age under appear-
ances that puzzle or deceive a common observer. To
these varieties the front teeth are most subject; the
lateral, least so ; which I ascribe to their comparative
utility and consequent attrition and wear. Every now
and then we meet with mouths in which the marks are

32 On the Changes which the Teeth undergo.

obliterated from the front and middle incisores in the
sixth year ; whereas others present marks even when
they are known to be aged : the lateral teeth in many
cases lead to a detection of this fallacious aspect ;
when they themselves partake of it, still other signs
are not wanting to aid us to rectify our conclusions.

Notwithstanding the teeth of the anterior jaw gene-
rally appear first, they retain their marks for several
years after the faces of the posterior incisores have lost
all vestige of them ; but this seeming paradox admits
of solution, when we remember, that their pits in the
first instance are nearly twice the depth of the others :
in addition to which, I believe, that the posterior teeth
wear faster than they do, in consequence of their out-
ward edges being so impressed, particularly in grazing,
in the act of vellication and division of the growing
herb.

" Monsieur St. Bel, the late professor of the English
Veterinaiy College, used to assert, that after eight years
the cavities in the anterior or upper incisive teeth Jilled
up with equal regularity ; thus from eight to ten the
front ones were filled up, from ten to twelve the two
middle, and from twelve to fourteen those of the
corner * ;" whereas a continental writer, whom I shall
name hereafter, avers, that the front teeth of the an-
terior jaw are planed by attrition, and their pits obli-
terated, in the ninth year, those of the middle in the
tenth, and those of the lateral in the eleventh. For
my own part, I have always regarded the anterior jaw
with considerable suspicion in determining age after
the fifth year ; at the same time, I must acknowledge

* Ree's Cyclopadia.~Vk]e « Age," m Horsemanship.

On the Changes which the Teeth undergo. 33

tl)at I am in the habit of examining it in ambiguous
cases from the ninth to the twelfth year, and that I
occasionally find my opinion confirmed by the successive
disappearance of the marks within that period.

Another but not less deceptive criterion of age is the /
aspect and form of the tusk. It is the common prac-
tice to minutely inspect the tusk after the fifth year,
and, with very many horsemen, mainly to rest their
opinion upon the condition of it ; so far am I however
f rom placing reliance therein, that I look upon it as the
res fallacissinia in showing the progress of age. This
tooth in the male generally arises, with the lateral
incisores, between the fourth and fifth years; but it is
by no means constant in its appearance at this age ;
it has been seen between the third and fourth years,
now and then it remains in its socket until the fifth year
is passed : in all cases it requires twelve months for its
complete evolution. About the expiration of the seventh
year, the point of its cone is blunted and rounded off ;
about the eighth, its spoon-like furrows, from its growing
convex inwardly, become superficial ; and about the
.ninth, they are completely filled up and obliterated.
/'After this, it gradually decreases in length, but at the
ssame time grows bulky, and acquires in the end a
fcylindrical form, and is then said to have become
rround; but the period of this transformation varies so
rmuch in different individuals that in no case should
• our opinion be grounded thereon.

English writers on this subject — from the earliest
ddown to White — appear to have transcribed their ac-
icounts, which were originally derived from the ancient
lauthors, almost word for word, one from another : they
fpToceed generally to the eighth or ninth year, and then

PART II. D

34; On the Changes which the Teeth undergo.

wind up the inquiry by saying, that horses that have
passed that time of Ufe are aged ; far from a design to
tax them however with any such meaning as the word
literally conveys, I take it merely as an import, that
" the marks are out of the horse's mouth," or that he
has passed that period beyond which, it is generally
believed in this country, no account can be rendered of
age by inspection of the teeth — as the French express
it, hors d'age. The continental writers, oh the other
hai^dj have long given themselves credit for discrimi-
nating ages to an advanced stage of Ufe ; and I must
confess I feel some surprise that no professional, man
among us has searched their woi:ks, and put, what ap-
pears to me to be, not only much novel but much valuable
matter of fact, into an English dress. Surely it is a
most desirable thing in our daily practice to be able to
tell, even within one year or two, age until the twentieth
year, thereby enhance our opinion arid set it above that
of a groom or jockey ; and probably it may strike some
as a little discreditable to us^ that, while every branch of
human medicine in this country, though comparatively
so vigorous and luxuriant of itself, is still enriched
with the flowers of the continent, the veterinary art
should continue so much in arrears ! But to return,
although our writers,may have used the word, aged, witli
the ineaning I have affixed, it certainly has, warped
and mis-fashioned the public opinion ; for nothing is
more common now-a-days than to see horses rejected,
without any inquii-y into their general, condition, purely
because the marks are out of their mouthS;:, B9 directly
at variance both with reason and experience does this
practice appear to me, that I will venture to assert, that
a Ijpr^e that has not been abused while young, is as

On the Changes tvhich the Teeth undergo. 35

uble — ay, many abler— to undergo trials of streilg'th
and labour at the ninth year as he was prior to it, and
from that year to. the twentieth, can perform more work
than he has done during the former part of life. In proof
of this (did my limits admit of it) I might inquire into
the ages of studs of hunters, stage-coach horses, cavalry
horses, &c. among which, I believe, it will unexception-.
ably be found, that an aged horse, if he have not been
ruined in constitution or crippled in his early years, will
withstand as much, if not more, fatigue than one that
has just attained or past the adult period. If it be true
then that horses that have been well treated while young
are able to do more work after the eighth or ninth year
than they have done before it, it follows that a know-
ledge of their subsequent age cannot fail to be of great
value to us ; in order that we may be enabled to calcu-
late, with a degree of precision, the probable number of
years they may continue to be useful.

The observations I am about to offer on this part of
our subject, I derive from a translation of a German
work, the production of M. Pessina, Professor and
Director of the Veterinary Institution at Vienna ; which
evinces much patient and laborious practical research,
and appears to have been drawn up, under very favour-
able auspices, with considerable accuracy and ingenuity.
I think it right however to preface these observations
with a paragraph of La fosse's, which certainly con-
tains the pith and marrow, and seems to have been the
foundation, of Pessina's doctrine : it runs as follows —

" In order to tell the age of a horse that has past his
eighth year, we must know that an incisor, considered
IS a whole, removed from its socket, is of a curved
pyramidal figure, whose outline it is difficult to trace

D 2

36 On the Changes which the Teeth undergo.

by description ; but, regarded in situ, the part exterior
to the gum will be found to be oval, after this manner

C^^^^^^^^> ^^'^ ^0 continue this shape from the comple-
tion of its borders to the tenth or eleventh year, during
which period however it approaches the succeeding
figure ; from this to the fourteenth year, it approximates

a circular figure, (^^^ ; from the fourteenth to the se-
venteenth, it has a triangular figure, ; from which
epoch it takes on and ever afterwards retains an oval
figure reversed, so *."

Let us now turn to the minute and circumstantial
details of Professor P e s s i n a . He systematically divides
the lifetime of the horse, which he computes at thirty
years, into six periods, that take their rise from and are
determined by an equal number of changes the teetli
naturally undergo in regular succession.

The first period is that during which the animal re-
tains all or any of his milk teeth : it extends from
birth to the fifth year.

The second period includes the sixth year, and conti-
nues so long as the marks remain visible upon the
faces of the posterior incisores : consequently, (with
reference to what has been heretofore stated,) it lasts
for the space of three years with eveiy pair of them.
After showing the rasure of the outward and inward bor-
ders, and the obliteration of the mark, in which I need
not follow him, the Professor concludes in remarking,
that in many instances, and especially among horses who

* " Mnmel. d'Hippiairigue." 3'. Edit. Par le citoyeri Lai-ossu.
p. 151.

On the Changes which the Teeth undergo. 57

have been kept at pasture, the faces of the front teeth,
and sometimes those of the middle, are worn off earlier.

The third period is that during which the teeth re-
tain the oval form. As the pits and marks degenerate,
the face slowly and gradually undergoes a deviation of
figure, from that of a pretty regular ellipsis, whose
long to its short axis bears the proportion of 6 to 3, to
an irregular one in which these proportions are as
5 to 4. This period requires on an average the space
of six years for its completion : the front teeth enter it
in the seventh and conclude it at the expiration of the
twelfth ; the middle pass through it one year later ; and
the lateral, one year later still.

In the fourth period the faces of the teeth assume a
circular figure, and hence have been denominated
round. At the commencement of it, the breadth of the
face to its thickness is as 5 to 4 ; at the conclusion, it
measures, in an inverse ratio, as 4 to 5 : about the
middle of it, the diameters are equal. This period also
endures six years ; so that the front teeth, which
enter it on the thirteenth year, complete it by the expi-
ration of the eighteenth ; the middle follow one year
later ; the lateral, one year later still.

During the fifth period the face deviates by slow de-
L,'rees from the round, and passes into the triangular
state. In the beginning, its thickness exceeds its
breadth as 5 does 4 ; in the end, as 6 does 3. It is the
professor's opinion, but as yet it is unconfirmed by
experience, that this period likewise, on an average,
includes a space of six years ; the front teeth therefore
complete it with the twenty-fourth, the middle with the
twenty fifth, and the lateral with the twenty-sixth year.

The sixth and last period is one in the course of
which an additional angle is projected from the ante-*

38 On the Changes which the Teeth undergo,

rioror inferior part of the tooth: Pessina distinguishes
it by the epithet biangular. From the paucity of the
number of hoi"ses that are met with so old, and from
the wear that the teeth have by this time undergone,
no writers on age have ventured thus far in their ac-
counts. Pessina never met with ahorse that had lost
his teeth from age ; but he has seen their faces ellip-
tical conti-ariwise, looking outwards or forwards. This
period is unlimited.

That there is a natural change going on during life
in the figure of the face, along with a variation in its re-
lative dimensions, it is certain, as well as that the tooth
sustains a continual loss of substance from manducation
and mordication ; but whether these eifeots proceed
uniformly with increasing years, it is not certain. Sup-
posing that it were so, the division of life into six pe-
riods is not without foundation, and is even practically
useful.

< The pit of an incisor is about four lines in depth, and
is filled or levelled in three years ; but it is not thence
to be concluded that the body shortens four lines. An
incisor is about 24 lines, or two inches, in length ; sup-
posing, then, that every year one line wears away, the
tooth wiUbfe diminished half an inch in every period.
Artd if you make half-inch sections of a perfect tooth,
the faces and proportions of its various pRits, will
elucidate these changes.

Most reliance is to be placed upon the lateral teeth
of the posterior jaw. They appear last, are ground
down last, and are consequently less operated on by
mechanical causes ; they are also more protected from
wear by their situation.

In computing age by this method, the period of life is
first to be ascertained \ the single years may be cal-

On the Changes rvhich the Teeth undergo. 39

culated afterwards by a careful comparison of one pair
of teeth with another. The enamelled border of the
pit, which, I have stated, takes on analogous figures so
long as it remains, will serve to guard us against de-
ception by any artifices that may be practised on the
exterior border.

In the anterior jaw, the marks disappear from the
I'ront teeth in the course of the ninth year ; from the
middle, in the tenth ; and from the lateral, in the
eleventh. What progress these teeth have not made
in transformation during the second period equivalent
with the posterior, they gain in the third : notwith-
standing the depth of pit, their proportions are then
the same. They continue three years longer in the
second, and consequently are only three in the third
period ; so that by the twelfth year, the third pe-
riod is completed by the front teeth, and so oh.
During the fourth, fifth, and last periods, the changes
are alike and equally perceptible in either jaw. So
far Pessin A thinks that the anterior teeth are entitled
to an equal share of our regard ; though, in the gene-
rality of cases, they need not be inspected : they ought
never to be passed by, however, when doubt hangs over
the case, and more particularly in the ninth, tenth, and
eleventh years. In such a remarkable manner the la-
teral teeth wear away, that they often put on the ap-
pearance of having been notched or indented.

In regard to the tusk, Pessina remarks, that he has
ound the least regularity in its changes of any tooth.
The very facts, that they are not in all horses cut at
the pame age, that they have little or no attrition against
nch other, and that they are worn by the tongue and
lod, sometimes much, sometimes little, would lead one

'40 On the Changes which the Teeth undergo.

to draw conclusions from them with extreirie caution :
in fact, as indications of age they can only be trusted
to when they accord with the incisores. The tusk
makes its appearance by the fifth, and is completely
evolved by the sixth year. In the seventh, the apex of
the cone is worn off. In the eighth, its furrows grow
shallow ; and in the ninth, they are obliterated. Then
it gradually wears away ; in the twelfth year it becomes
round ; from which time, though it grows shorter, its
shape varies but little. But it is not uncommon to see
it blunted like an acorn in the ninth year, nor to find
it still pointed in the sixteenth or eighteenth.

Pessina concludes his account of the changes to
which the teeth are subject, by observing, that, as they
are dependant on wear, which is no law of Nature,
but an effect of mechanical and accidental causes,
they cannot, but under certain limitations, be implicitly
relied on.

I shall now subjoin a translated extract from a Frencli
veterinary periodical pamphlet * that has made its ap-
pearance with the present year, which will show how
far the professors of the School at Alfort, whose united
opinions it breathes, tread in the steps of Pessina, and,
at the same time, serve as recapitulatory of the prin-
ciples— for there they agree though they are at var iance
in the periods — upon which the German professor has
built his ingenious system of ages.

" At eight years of age (in most horses) the rasure—
the disappearance of the marks— is perfect; the teeth

* " Nouvclle Bibliolhequc M'cdicale, augmcntce d'tin Rcctieil de Medi-
cine VUcrinaire. Caliicr d'Avril." Just as these lectures were going to
press, Mr. Sew£ll, with his usual kindness,- sent me this number.

On the Changes ivhich ihc Teeth undergo. 41

are all oval ; the central enamel * upon the face is
triangular and nearer to the outward than the inward
border, and the cul-de-sac of the cavity of the tooth
appears within the outward border like a yellowish band
carried from one side to the other f-

" At nine years, the front teeth grow round, the
middle and the lateral contract their oval faces, and
the central enamel diminishes and approaches the in-
ward border.

" At ten, the middle teeth grow round, and the cen-
tral enamel has approximated the inward border and is
rounded.

" At eleven, the middle teeth are rounded, and the
central enamel is almost worn off the posterior in-
cisores.

" At twelve, the lateral teeth are rounded, the central
enamel has quite disappeared % ; the yellow band, grown

■ The inner rim, surrounding the infundibulum.

f " It is not of so deep a hue as the other bony part of the face,
doubtlessly because it has not existed so long. For it has been re-
marked, that the bony substance turns yellow with age : in very
young teeth, it is milky white." — Loc. cit.

" Prior to the destruction of the first of these iriarks — the central
enamel — when it is approaching the oval figure, the cul-de-sac of the
cavity of the pulp makes its appearance anterior (or inferior) to it,
nlong the outward border of the face, in the shape of a zone, at
first yellowish and running broadwise, then round and greyish,
afterwards white and extended from before backwards. It essen-
tially differs from the first mark in never becoming prominent, but
is always upon a level with the rest of the face ; it is observed also,
that it does not wear away, or, if it does, that a little, round black
cavity is found in the place of it." Letter J'roin M. Gikard to

M. TiSSIER.

\ " Tliis happens in all of them at the same time."— For, tliough
the front teeth exceed in length the middle, and they the lateral.

42 On the Changes which the Teeth undergo.

wider, occupies the middle of the face, and the central
enamel continues in the teeth of the anterior jaw.

" At thirteen, all the incisores are rounded, the sides
of the front teeth spread out, and the central enamel
continues in the anterior jaw, but is round, and ap-
proaches the inward border.

" At fourteen, the (faces of the) front incisores put
on a triangular appearance, the middle grow out at
their sides, and the central enamel of the anterior teeth
diminishes ; but it still exists.

" At fifteen, the front teeth have become triangular,
the middle enter upon that figure, and the central
enamel of the superior jaw is still visible.

" At sixteen, the middle are triangular, the lateral
commence that shape, the anterior central enamel has
generally (souvent) disappeared.

" At seventeen, the triangular figures of the poste-
rior jaw are completed ; but their triangles are equi-
lateral until

" The eighteenth year. Then, the sides of them
lengthen in succession from the front to the lateral
teeth, in such a manner that

" At nineteen, the front teeth are flattened (aplaties)
from side to side.

" At twenty, the middle have taken on the same
shape ; lastly,

" At twenty-one, the lateral teeth assume it."

Leaving these doctrines of tlie continental professors
to the tests of further observation and experience,

and their infundibula are of proportional depth, as the first arc
worn down two years, and the second one, before tlie lateral, it
follows that their pits, which are of equal depth when the lateral
are cut, are all obliterated at one time.

On the Changes xohkk the Teeth undergo. 43

.vhich can only be decisive upon a large scale and un-
ler certain favourable circumstances, and to the com-
nents of those who may have already reaped the scien-
ific advantages of such situations, I shall now briefly
idvert to the after-growth of the teeth, and conclude
his lecture, which has already become extra-limited,
vith some few remarks on old age.

That there is an after-growth or continued accretion
if the teeth, observes Pessina, is evident and indis-
putable ; were there not, the gums in the course of
lime would have to grind the food ; for wear or destruc-
ion of their faces is going on without intermission, and
.V ith more or less regularity according to circumstances,
f would advance as additional proofs, that the ena-
iiel that encases the body of the tooth can only disap-
)ear by a process of destruction, no more than that
vhich lines the pit, and that the circumstance of their
■oncurrent gradual diminution shows that the seat of
vear is the face ; so that in old horses the incisores
lave no enamel, inside or outside, and hence their yel-
ow aspect and disposition to tartareous incrustation.

The professor estimates the wear according to the kind
)r breed of the horse; in one that is thorough-bred,
it one line per annum; in others, at one line and a
lialf. And it appears that the shoot frbm the jaw is
I bout equal to this ; so that the original length of every
looth is still preserved. Whenever the consumption
iiowever is not equal to the growth, (the one a mecha-
nical, the other a living process,) the aspect of the
I'icth can no longer be a criterion, or but a fallacious
fine, of age : then, as Girakd {Jils) remarks, the only
'uethod of rectification must consist in SE^wing off the
teeth to their natural length.

44 On the Changes which the Teeth undergo.

Pessin A has told us that the natural age of the horse
is thirty : I must confess myself, I should have rated
it higher. At all events, it is by no means uncommon,
among horses that have been kindly treated, to meet
with instances of greater age : — in the riding school at
Woolwich, a horse, named Wonder, died, some years
ago, at the age of forty ; in the year 1822 a favourite
horse of Mr. Walrond's, of Badfield House, Devon,
died at fifty ; and within the same year, a memorable
instance of advanced age, a parallel of which, I be-
lieve, is not on record, took place in a horse belonging
to the Mersey and Irwell Navigation, who died in his

sixty-second year * !

I remarked in the last lecture, that the jaws in old

age grew narrow and straight, projected with less bow
downwards, and, as it were, crowded the incisores, and
gave them a horizontal inclination ; but they not only
contract, they undergo (like the teeth at a less ad-
vanced period) a process of internal consolidation.
For there does appear to be a time when the tooth
ceases to grow at the root, though it still continues to
issue from its socket and make up for the loss from
wear ; and the result is, that the fang shrinks and be-
comes pointed, and is carried upwards along with the
tooth in the alveolus, whence it would loosen and fall
out, were a process of interstitial deposition and con-
traction not set up in the jaw, by which it is constantly
embraced, and still held immoveable and firm. At this
time, the teeth, as if they were squeezed together,
grow flat at their sides, along which they are in close

V* jj^p jjg^jj jjjjg animal would have been a most desirable
present to a public veterinary establishment : it becomes compara-
tively valueless when it falls into indifferent hands.

On the Changes which the Teeth undergo. 45

. ontact ; they stand out almost horizontally from the
laws; they are longer, both because their wear appears
o be less in that position, and because the gums shrink
. om their bodies ; they take on a sickly yellow hue,
ind are often, about the gum, incrusted with a sub-
stance like tartar; the outer edges are more or less
vorn, giving the faces a variety of shapes; and the
eeth of the anterior jaw, still farther over-hang their
)pponents.

Accompanying these, there are many signs of age
mconnected with the teeth. The head grows lean and
ine ; the features look more striking ; the hollows over
he eyes deepen ; the eyes themselves grow irritable and
winkle ; the cheeks become lank ; the gums and soft
lalate, pale and shrunk ; the submaxillary space is capa-
ious ; and grey hairs make their appearance in various
)laces, more particularly over the eyes, and about the
ace. In regard to the body generally, it also makes a
aore striking display of its shapes than in any former
lart of life : the neck grows thin and fine ; the withers,
row sharp, and give an appearance of increased length
nd obliquity to the shoulder; the back sinks; the
juarters assume a more blood -like turn, and seem to
ngthen ; tumors of all kinds— spavins, splints, wind-
falls, &c. generally become in part or wholly absorbed ;
he legs feel sinewy and free from puff, though they
vince instability and weakness. Now-a-days it is not
ften however that we meet with horses thus advanced
II years, still more rarely with any that have grown de-
repit from age.

LECTURE XXVI.

Particular Descriptions of the Muscles.

Having, on a former occasion *, taken a cursory
view of the structure and economy of these organs in
general, I shall, in this and the following lectures, di-
rect my attention to them as they appear on dissection.

In describing any particular muscle there are four
considerations to be borne in mind, two of which are
indispensable, and the other two, or even one of them,
but rarely lost sight of without manifest defect or impair-
ment in the description : the two first alluded to, are
attachment and wse; the two last, figure and situation or
course. With regard to the first of these considerations
— attachment, it may be useful to repeat a sentence
out of the lecture referred to below. — " That extremity
from which it (a muscle) arises, commonly connected to
some fixed or very limitedly moveable part, is called its
origin or head ; the other, implanted into the part to be
moved, the insertion or termination of it ; while the por-
tion intermediate— between its head and termination —
receives the name of body or belly:' Although I shall

* Lect. xii. Part I.

Particular DesctHptiom of the Muscles. 47

ndeavoiir to be as concise in my myological details as
the nature of the subject will admit, I shall at all times
implify, and be minute in anatomical inquiiy, when
my important pathological fact can with advantage be
llustrated ; and, indeed, at one time so resolved was I
1 be guided by this consideration, that I had excluded
Vom these lectures many muscles of minor interest,, as
jeing rarely or never implicated in disease : subsequent
leliberation, however, has led me to doubt that a course
)f anatomy thus constructed, is sufficiently solid ground-
vork for a veterinary student !

Concerning the nomenclature here adopted, as I
)rofess to follow, so long as the analogy can be pursued
vithout incurring the risk of impropriety or misconcep-
!on, that at present in most popular use in human ana-
omy, I may have introduced some innovations : all
liat I can say in justification of myself, is, (for I ad-
lit that the practice is reprehensible,) that we have
10 written authority of sufficient importance to bow to,
nd that I have spared neither time nor pains, in my
lissections, and that therefore I have ventured, always
ceeping my standard in view, to affix, what I conceived
o be, to every muscle the most appropriate appellation.

As a pupil at St. Thomas' Hospital, I remember to
lave reaped several advantages from the classification
)f the muscles (and more especially of those of the
leck and back) into regions: I found them with more
acility, I understood better their relative situation,
nd I had less difficulty in retaining then* points of
ittachment in memory. Aiad I cannot doubt, if my at-
empts at a similar distribution of those of the horse
hould prove happy, that equal assistance will be affisrd-
d by it to the juvenile veterinarian. But there is one
nuscle which defies any arrangement ofi this kind — one

Parinkulus Carnosus.

that not only extensively clothes the trunk, but pervades
the neck, and even spreads its fibres upon the head :
this, in conformity with custom, I shall commence my
myology with.

Patmiculus Carnosus.

A CUTANEOUS muscle peculiar to quadrupeds, which
foiTnerly, from its close connection with the skin, was
regarded as one of the exterior coverings of the body ;
we shall find, however, in the dissection of it, that
their attachment is purely cellular, consequently that
they are, in an anatomical point of view, two per-
fectly distinct and separate parts. This pair of muscles,
or, as St u BBS calls them, " the fleshy pannicles," are
spread over, or clothe as it were, the lateral parts of the
body, extending forwards upon the shoulder, along the
neck, to the head, and backwards upon the belly as
far as the stifle. The integument covering the abdo-
men adheres to the muscles thereabouts by a quantity
of cellular membrane, which, upon the central parts of it,
is of a close and dense texture, and binds the skin witli
extreme tenseness ; but upon the sides it is loose and
plentiful, and towards the posterior part of the belly
forms a thick and distinct layer that corresponds to
what is named inhuman anatomy ihe fascia superficialis.
In prosecuting the dissection from the middle of the
belly to the sides, we find immediately underneath, and
in some places intermingled with, this cellular mem-
brane, a thin layer of muscular fibres belonging to the
panniculus*. This cellular envelope is principally

* The panniculus is much blended with tlie fascia superficialis :
tliey must be both taken off with the skin in order to lay bare the fi-
bres of the external oblique muscle.

Panniculus Caiifiosus.

■49

foniied by a s?eparation of the layers of the fascia super-
ficialis, which, after having given a covering to the penis
and testicles, is continued down upon the inside df the
thigh. These remarks will prove of some assistance in
tracing the disposition and connections of the abdominal
portion of this muscle, which is too often but imperfectly
displayed, in consequence of not having paid sufficient
attention to the preparatory or cleaning stage of the
dissection.

Origin. The attachments of this muscle are chiefly
cellular ; though in some parts of it tendinous fibres are
veiy demonstrable. Its most anterior origin is, by means
of a few pale disgregated fibres, some of which may be
traced as high up as the root of the ear, from a thin fas-
cial expansion covering the muscles upon the side of
the face. These scattered fasciculi become strong
and convergent about the angle of the jaw; but,
having quitted this part, they are again spread out and
scattered over the anterior and lateral parts of the neck,
blended, on either side, with the fibres of the levator
humeri, and intimately united with the fasciae of these
parts. From this, which may be called its cervical por-
tion, some little fleshy bundles are seen running to the
spine of the scapula, to which they are loosely attached
by abundance of cellular membrane ; others, paler and
less distinct, are continued down over the shoulder-joint,
where they become embedded, and many of them lost,
in cellular and adipose substance: the unexpended fi-
bres may be traced onward into the fascia of the arm.
From these attachments — viz. the cellular and fascial
mvestments of the lateral parts of the head and neck,
the spine of the scapula, and the fasciae of the shoulder
and arm, is formed a broad but thin fleshy expansion

PAHT II, E

50

Panniculus Carnosus.

; upon the side, the fibres of which take a direction, up-

wards and backwards, to the spine ; to which, although
they may be said to be continued to it by the intervention
of fascia, they are not immediately fixed : no fleshy
fibres ascend higher than the top of the scapula. This,
the thoracic portion of it, gives a covering to the side of
the chest, though in some places it is extremely pale
and indistinct. Upon the posterior and inferior parts
of the belly its fibres converge into a fan-like band,
which is continued, by means of a tendinous and cellular
elongation, into the fascia covering the stifle-joint,
whence a portion of it is reflected inwards to the pubes.

The fibres of the panniculus are strongest just behind
the scapula, and upon the more prominent pai'ts of the
belly. They adhere to and conceal many other muscles,
the principal of which are — the obliquus externus ab-
dominis, latissimus dorsi, postea et antea spinati, and
parts of the triceps and serratus magnus. Anteriorly
it is so intimately blended with the levator humeri, that
there is much caution required in the dissection, other-
wise one will be reflected with the other : its fibres are
also mingled about the breast with those of the pec-
torales.

Insertion. Into the skin that every where covers it,
chiefly by the interposition of cellular membrane : this
membrane, as I have already shown, varies in texture
and quantity * in different parts, and here and there is
traversed and strengthened by ligamentary cords.

Use. These muscles serve to give motion to, and to
corrugate, those parts of the skin into which they are
inserted : the skin itself being incapable of such con-

* This will depend in some measure on the condition of the
horse. Vide Lect. ix. Part I.

5toi

■

Muscles of the Trunk. 51

I action, is thrown into folds that form right angles
with their fibres. The chief points from which they
act are, the angle of the jaw, the scapula, the patella,
and the pubes. By suddenly and repeatedly wrinkling
the skin, the horse (unprovided with hands for the
purpose) startles, and thus dislodges, those insects
with which during the summer months he is continually
infested : he has also the power with it of displacing
foreign bodies of inconsiderable weight or magnitude
from his coat, such as dirt, prickles, hay-seeds, &c. and
of resisting, to a certain degree, the gripe or bite of an
adversary. So habitual indeed does this cutaneous
iction become, that the panniculi seem often to contract
nvoluntarily, or at least unheeded by the animal, on
he application of any irritant : this is particularly re-
uarkable when a horse that is grazing or feeding is
innoyed by flies. M. Girard thinks, that it adds to
he power of those muscles which it braces much when
n action *.

Muscles of the Trunk.

ABDOMINAL REGION.

After having dissected off the panniculus camosus
rom the abdomen, together with the cellular membrane

II which it hes embedded, several white tendinous lines,
imning in different directions, come under our notice,
'he one that extends from the ensiform cartilage to the
ubes, has received the name of linea alba : it marks the
lace of junction of the tendons of three pairs of abdo-
linal muscles, and is perforated near the middle by the

* — " II concourt a augmenter la force des muscles sur Icsquels il
<erce une pression un pcu forte." Anat. Vet. p. 233. torn. I. , .

E 2

62 Obliquus Externus Abdominis.

umhelicus or navel ; through which in the foetus passes
the nmbelical cord. On either side of this line is another,
taking a curvilinear course, called the linea semilunaris :
this is the line of demarcation between the oblique and
transverse muscles and their tendons — denoting where
the one substance ends and the other begins. Running
transversely between these are several white lines, to
which the name of linea transversales is given : they con-
sist, as will hereafter be seen, of so many tendinous in-
tersections in the straight muscles.

There are four pairs of muscles of the abdomen :—
two pairs are oblique : one transverse ; the fourth is
straight : in the human subject, a fifth pair is generally
present, called the pyramidal.

Obliquus Externus Abdominis.

This muscle is covered by a tendinous expansion,
called the aponeurosis of the external oblique muscle, which
must be carefully dissected off in order to bring into
view its fleshy fibres ; but so intimately is this sub-
stance united at the linea semilunaris with the tendon
of the muscle, that they will not admit of entire separa-
tion by the knife.

Origin. By finger-like, fleshy processes, called digi-
tations, from the posterior edges of the fourteen hinder
ribs, near to their cartilages — digitating with the serratus
magnus and intercostal muscles — by tendinous fibres,
from the posterior spinous process of the ileum, and
from the fascia lumborum*. From these attachments

* A strong ligamentous fascia, attached to the spinous pro-
cesses of the lumbar vertebrse, and to several of the hinderraost
dorsal : it invests the superficial muscles about the loins.

Obliquus Externus Abdominis. 63

its fleshy fibres, which regularly increase in length from
its anterior to its posterior border, run obliquely down-
wards and backwards, decussate in their course those
)f the internal oblique, (the layer of muscle above them,)
and at the linea semilunaris send off a tendinous expan-
sion of great breadth.

Insertion. Into the entire length of the linea alba.

The portion of this muscle which arises from the pos-
terior spine of the ileum, is particularly worthy of re-
mark ; from it proceed two elongations of tendon, one
of which, comparatively thin and weak, is stretched
across to the pubes, where it is firmly fixed ; this con-
stitutes what surgeons call Poupart's ligament : a part,
however, by no means well defined in the horse. The
other process of tendon, much stronger, is continued
down upon the inside of the thigh. At the posterior
and lower part of the belly, on either side, we perceive
a round opening in the aponeurosis and tendon of this
muscle ; this is the abdominal ring : through it in the
male the spennatic cord passes from the cavity of the
abdomen into that of the scrotum ; in the female, it gives
passage to the round ligament. This aperture, which
is formed by the division of Poupart's ligament into two
columns, is at first but indistinctly seen, from being in-
vested by some cellular and adipose substance that con-
nects the cord to the surrounding margin of it. At this
part the aponeurosis is much strengthened by numerous
transverse tendinous fibres, which run from the linea
alba towards the spine of the ileum.

Use. The uses of these muscles are — to contribute
largely to the formation of the under and lateral parts of
the abdominal parieties, and to give support to the con-
tained viscera ; to compress the bowels occasionally, and

64 Obliquus Internus Abdominis.

by that means assist in the evacuation of foeces and
urine, and in the expulsion of the foetus ; to diminish
the cavity of the chest from before backwards, by thrust-
ing the diaphragm forwards, through the medium of the
abdominal viscera, and from side to side by laterally
compressing and retracting the ribs. To see these
muscles in action we have only to observe a horse in the
act of voiding his fceces ; or, one whose respiration has
become laborious: the animal draws or tucks up his
flanks by the contraction of these and other muscles ; he
works or heaves at the flanks by their alternate and
forcible contractions and relaxations.

By reflecting the external oblique — from its origin —
we expose the

Obliquus Internus Abdominis.

t The fleshy fasciculi of this muscle are spread out in
the shape of a fan.

•igiri. Its fleshy fibres, collected together, arise
irom the spine of the ileum, covered by those of the ex-
ternal obhque ; from which point they radiate in a
contrary direction — downwards and forwards — and ter-
minate, with great regiUarity, in a semicircular border.

Insertion. From this border is sent off a broad thin,
tendon, which at the linea semilunaris becomes insepar-
ably united with the aponeurosis of the external oblique :
here it splits into two layers, of which— the external,
the stronger one, is inserted into the cartilages of all the
false ribs, into the cartilage ensiformis, and the linea
alba ; the internal, consisting of some thin scattered fi-
bres, accompanies the tendon of the muscle next to be
described.

•i. U$e. These muscles will assist the former in action,

I'ransversalis Abdominis. — Rectus Abdominis. 55

as well as in sustaining the viscera ; they will have more
effect however in the expulsion of foeces and urine than
as muscles of respiration : they are particularly called
into action when the flanks are much tucked up by any
violent efforts.

Traiisversalis Abdominis,

Is a thinner and broader muscle than the last de-
scribed, and one that closely invests the abdominal
viscera.

Origin. Fleshy, from the inward surfaces of the car-
tilages of all the false ribs — digitating with the fleshy
fibres of the diaphragm — from the fascia lumborum, and
from the anterior spine of the ileum. Its course, as its
name implies, is directly across the abdomen : it is
wholly tendinous at the linea semilunai-is, and enters
into inseparable union with the internal divison of the
tendon of the internal oblique.

Insertion. Into the ensiform cartilage, and into the
entire lenscth of the linea alba.

Use. The trans versales aid the oblique muscles in
supporting the viscera, and are more advantageously
placed to effectually compress them ; thereby, they are
doing much towards the evacuation of the bowels,
as well as in the protrusion of them against the dia-
phragm *.

Rectus Abdominis.
Tins muscle, on either side, is enclosed within a

The fleshy fibres of this muscle arc continued further back-
wards than those of the internal oblique, but, like tliem, end in a
round tendon that crosses over the cord in the form of an arch : this
r orresponds to the crural arch of the human subject.

66

Meet lis Ahdominis.

sheath, constituted of the tendons of the external and
internal oblique inferiorly, and of those of the internal
oblique and transverse muscles superiorly. As has been
stated, by a careful dissection, the tendon of the inter-
nal oblique may be seen to split into two portions at the
linea semilunaris, one of which passes under, the other
above the rectus ; so that, in fact, the muscle itself is
actually placed within the tendon of the internal ob-
lique. The sheath in several places adheres firmly to
the muscle, and its fleshy belly is intersected at those
parts by portions of tendon, whose situation and course
are denoted externally by the linese trans versales.
These are thin muscles of considerable length, and, as
may be inferred from this remark, by no means power-
ful ones : they compose about one-third of the abdo-
minal superficies.

Origin. From the cartilages of the seven posterior
true ribs, and from the sternum. Thence it is stretched
along the under part of the belly, bounded on the one
side by the linea alba, and on the other by the linea
semilunaris.

Insertion. Tendinous, into the pubes, near to the
symphysis.

Use. The chief use of these muscles in quadrupeds,
appears to be that of bracing the middle parts of the
belly, and, thereby, of counteracting that tendency to
relaxation which must exist from the constant depend-
ance of the bowels : for this purpose, they are much
broader, though thinner, than in the human subject.
The recti will also have some effect in the compression of
the bowels, and, by drawing the sternum upwards and
backwards after inspiration, in the contraction of the
thorax.

The cavity of the abdomen is closed directly behind

Hernia.

57

■ he abdominal ring by the internus obliquus and trani/-
versalis; under the crescentic borders of which the
spermatic cord is taking its course along the inguinal
ranal, and entering the cavity by an opening at the up-
per part of it, called the internal abdominal ring. This
aperture, let it be remarked, is not placed opposite to
the external ring, but at the space of three inches from
it outwardly, and somewhat anteriorly to it ; no intes-
tine therefore can protrude directly through the exter-
nal ring ; (at least I have never heard of any instance of
it ;) but inguinal hemiae in the horse are all oblique,.
!. e. they pass out of the abdomen at the internal ring,
and proceed with the spermatic cord down the in-
guinal canal, through the external ring, into the scro-
um.

If, with care, an incision be made through some of
he posterior fibres of the transversalis, we shall find,
hat, instead of having laid bare the peritoneum, we have
xposed an expansion of fascia of considerable density
ind firmness of texture: this part Sir Astley Cooper
irst described, and called the fascia transversalis. It
nay be traced, without much nicety of dissection, as an
entire lining to the soft parts of the abdomen ; and is,
Tom the resistance it opposes, which is by no means in-
•onsiderable, in the horizontal position of the trunk, of
essential service in sustaining the burden of the de-
fendant viscera ; and, in so doing, reduces the demand
or muscular action. In it is formed the internal ab-
lominal ring.

Hernia.

By hernia or rupture is meant, the protrusion of some
v iscus — commonly intestine — and along with it a sac

58

Hernia.

or pouch of peritoneum, from the cavity of tlie belly.
In the human subject there are many situations that
have shown this disease, from w^hich and from the na-
ture of the protruded part, it has been distinguished into
several kinds, and these have received appropriate tech-
nical appellations : the only varieties I have met with in
the horse, are bubonocele, or inguinal hernia, in which
the intestine* descends with the spermatic cord, along
the inguinal canal, and lodges in the groin ; and osche-
ocele, or scrotal hernia, in which the gut continues its
course into the scrotum. When the contents of the
swelling can be returned into the abdomen, the hernia re-
ceives the epithet, reducible; but when that is impractica-
ble, either from considerable augmentation to their bulk,
or from adhesions to the sac, or to one another, it is said
to be irreducible. Should there be constriction at the
mouth of the sac— the internal abdominal ring — so that
the circulation is either impeded or arrested, the her-
nia is said to be strangulated.

Hernia is a much less common disease in the horse
than in man, owing to the dependance of the viscera
not being upon those parts of the belly likely to admit
of protrusion — the abdominal rings ; indeed, in this
country it is a rare occurrence, which, there appears
reason to believe, is ascribable to the general practice of
castration : I suspect however that we are not apprized
of\its existence in very many cases. For, if the horse
be the subject of bubonocele, unless our attention be
directed to it by symptoms of strangulation, we are not
likely ever to discover it ; and indeed oscheocele, if

* t belief the part protruded is unexceptionably intestine. The
omentum e horse is too short ever to become hernial.

Hernia.

59

the escaped portion of gut be but small, may be present
through life without exciting even a suspicion of it. But
if the hernia be large, it will be readily recognized by
lie sudden appearance of a swelling of considerable
magnitude between the thighs, that extends for more or
less along the belly, is tense and elastic, and percepti-
bly expansible, when softly compressed, from eflforts in
coughing. Unless there be any tendency to constric-
tion, the only inconvenience attending these swellings
appears to be their bulk.

The subjects of hernia we find almost unexception-
iibly to be, horses that have been overstrained by sud-
den and violent acts of galloping or leaping : the for-
cible retraction of the diaphragm displaces those viscera
that lie within the confines of the ribs, the ribs, being
tightly embraced by the girths at the time, are unable
to yield and give more space laterally, the consequences
are that the bowels are all thrust backwards, and that
one of the guts (they being the parts most loosely con-
nected) is protruded from the cavity. Thus it is, that
racers that have undergone severe courses of training,
and hunters, are the ordinary subjects of it. Mecha-
nical injury to the belly will also sometimes give rise
to hernia ; of which I shall presently relate an instance.

In all cases of reducible hernia we can with fa-
cility sensibly diminish the bulk of the swelling,
though I am not acquainted with any means but
what mostly prove abortive in the permanent reduc-
tion of it. If it have arisen from an injury of any kind
that is followed by inflammation of the parts, we ought
to bleed, give purgative medicine, feed with hay chaff,
bran mashes, and water gruel, and keep the swelling
continually wet with the Liquor Plumb : Subacet ; Dil :

60

Henvia.

or spirit lotion, before we made any attempts to re-
turn the gut. When the tumefaction has subsided,
and the parts have become soft and compressible, the
reduction is commonly easily effected : indeed, the gut
will now and then slip up spontaneously, as soon as the
animal is cast upon his back. In this position a com-
press may be applied, and retained in its place by a
broad and suitable roller : should this, which is difficult
of adjustment, not answer the purpose, I should be in-
clined to rub a liquid blister over the scrotum*.

Mr. Hodgson, V. S. who has lately returned from
India, where, for the last seven years, he has been pro-
fessionally employed by the Company, has, at my re-
quest, kindly drawn out the following sketch of hernia,
as it is met with there : it will be found to contain many
practical hints, relative to strangulated hernia and the
operation for it, well worthy of our consideration.

" In Asia, where it is not the custom to emasculate
horses, inguinal hei-nia is of frequent occurrence : the
animal is supposed to have the gripes. When strangu-
lated, it generally ends in death. It mostly happens after
sudden exertion ; our inquii'ies about its origin, there-
fore, ought invariably to be particularly directed to that
point. In strangulation, the symptoms resemble those

* In 1820, Mr. C. Percivall, V. S. 11th Dragoons, went to see
a black cart colt that had received a kick, five days before, from
another at straw-yard. He found a large swelhng along die
posterior and inferior part of the belly, which was soft and yielding,
as if it had been a bladder half distended with air. He easily
reduced it, and applied a compress and roller, bled and gave some
aloes. In three weeks, though considerably diminished in volume,
the intestine was still very perceptible. "After this, I blistered
the part, and certainly with good effect ; but the scrotum ever after-
wards remained hernial."

Hernia.

61

of the colic or enteritis ; in which disease, as well as
Ml hernia, the testicles are drawn up ; but in the latter
case, only one is retracted, and that becomes turgid,
•.uid lai^er than the other, in consequence of the impe-
diment to the return of blood at the ring. The portion
of protruded intestine may be too small to be felt ; but,
if there be reason to suspect its descent, we must
not await the approach of other and more decisive
symptoms, but proceed at once to the operation ; which
-should be performed in the following manner*.

" The horse ought to be thrown upon his back ; the
Hmb of the affected side then released from the hob-
bles, and drawn upwards by a rope, passing over a
beam, so as to fix it in a position that may be varied at
the pleasure of the operator." This would be a most fa-
vourable time to employ the taxis. I would endeavour to
confine him in this position, and then — having debilitated
him and relieved the plethora of the parts as much as possible

* That vomiting may be present with these symptoms, the case
below informs us ; and I should expect to find others, such as analogy
would dictate :—costiveness— fulness, tension, and tenderness of
the belly — altered pulse— expression of pain when the scrotum or
hernial parts were compressed, &c.

"On July 22d, 1806, a strangulated intestinal hernia proved fatal
to a tall stallion, surnamed Le Coq, one of the stud for experiment
(haras experience) at the Veterinary School, Alfort; the animal
only survived three days, during which his sufferings were extreme.
Some moments before he sunk under this affection, he vomited, at
several ejections, a pretty considerable quantity of fluid, consisting
chiefly of the beverage that had been given to him."

" On opening his body, which was done immediately after death,
the hernial portion of the small intestine was found gangrenous ;
the stomach contained much liquid matter, was pale, and so soft
that it was torn through with facility." Traitc d' Anatomic Veteri-
'uure, par Giraud. Vide Mcmoire stir le Voinissevient. p. 23.

62

Hernia.

by one or two copious bleedings, piior to casting — Iwouhl
cover the affected parts with powdered ice, or, could that not
be procured, I would direct that several buckets of cold
water be dashed upon the parts, or some refrigerant mixture
be applied to them. If the gut could be felt, skilful compres -
sion of the parts (technically tei-med the i axis) might reduce
it ; but whetlier it were perceptible or not, I would employ
the taxis after the parts had lain an hour or more enve-
loped in ice, and if I found their volume much diminished,
I would allow the animal to rise. The tobacco enema
might also be made trial of. " The operation, in itself a
difficult one, is often rendered embarrassing and irksome
by the stmggles of the patient. Having made a small
opening at the bottom of the scrotum, into the cavity of
the tunica vaginalis, pass the finger up, along the cord,
as high as possible ; then, pressing the finger outwards,
make a second incision through the skin so as to lay
bare the point of it"— now in the inguinal canal — " and
enable you to examine the ring. Should intestine be
discovered, make every effort to return it into the belly ;
but if that prove impracticable, introduce a small bis-
toury, guarded at the point, along the finger, and divide
the stricture : in doing vs^hich great caution is required,
that the dilatation made by the incision" — which should
be directed upwai'ds, as the horse lies — " be barely suffi-
cient to admit the recession of the gut ; if it exceed
this much, as soon as the animal struggles, fresh intes-
tine, and more in volume, will present itself, and the
operator find himself embarrassed, if not foiled, in re-
turning and confining it, from the obstacles that
oppose the application and retention of a truss or com-
press *.

* " In some cases the gvit mav be felt, when the finger is passed

Hernia. 63

The Government of India have lost, in times past,
a o reat number of horses from hernia : I believe that I
first introduced.this mode of operating, and I can safely
ay, that it has been the means of saving many. Out of
ten cases of strangulation that came under my observa-
tion during the first tw^o years, but four w^ere lost : tw^o
died in which the disease was not known to exist before
death ; the other two fell victims to over-dilated stric-
tures, whereby the guts could not afterwards be re-
tained in the belly."

lip; but, when it cannot, we are not to be deterred from proceed-
ing. By making the incision at the loiver part of the scrotum, not
only is the operation rendered less difficult, but we have afterwards
a dependant opening, in case of abscess ; which is now and then
:i sequel of it. I have been informed that, V. S. Anderson)
of the 24th Dragoons, after having opened the scrotum and re-
duced the hernia, was in the habit of employing the clams; but
with what success I never heard."

P. S. — At the time that this Lecture was printing, Mr. Sewell
-liowcd me a horse in the College, that had a protrusion of intestine,
ibout the size of a small apple, a little behind the cartilages of the
false ribs, amid the fleshy fibres of the internal oblique and transverse
muscles. Moderate pressure upon it, immediately reduced it, and
tlien, with one or two fingers, tlie skin (which was loose there-
abouts) could be pushed, through the opening, into the cavity of
'!ie belly. This adds another variety to the aforegoing description,
•ind comes uuder the denomination of ventral hernia.

LECTURE XXVII.

DOKSO-SCAPULAR REGION.

The muscles of this region well deserve our attention,
being three of the principal agents employed in the
motions of the shoulder.

Trapezius.

In grasping the withers we include this pair of
muscles between our thumb and fingers. The trapezius
is of a triangular figure, and is covered by a tendinous
expansion, derived from the ligamentum subflavum *.

Origin. From the spinous processes of the third,
fourth, fifth, and sixth dorsal vertebrae, and from the
fascia covering them. Its fleshy fibres converge, run
downwards and forwards, over the superior costa of the
scapula, and there unite in a flat tendon.

Insertion. • Into a little tubercle upon the spine of the
scapula.

Use. It is an elevator of the scapula — it draws the
scapula upwards, and, at the same time, inclines it
backwards.

* Improperly called the ligamentum mudue.

Latissimiis Dorsi. — Rhomboideus Brevis. 65

Lfitissimus Dorsi.

Partly concealed by the trapezius. In figure not
unlike the scapula itself, from the upper and back part
of which it is extended to the back and loins.

Origin. By a broad aponeurosis, which is stretched
over the posterior part of the back, and over part of
the loins, from the ligamentum subflaviun. Its fleshy
fibres make their appearance upon a level with the top
of the scapula, converge in their course downwards and
forwards over the ribs, to which they are loosely at-
tached * by cellular membrane, as well as to the poste-
rior angle of the scapula.

Insertion. By a long thin tendon (which is connected
with the teres major, along with it) into the inner and
upper part of the body of the os humeri.

Use. To draw that bone backwards and upwards.
By raising the lower part of the shoulder, it will much
facilitate the motions of the scapula in progression.

Rhomboideus Brevis.

A BROADER and much shorter muscle than the rhom-
boideus longus, which I shall next describe.

Origin. In part concealed by the trapezius, from
the four or five anterior dorsal spines. It passes directly
lownwards to the scapula, uniting in its course with
the longus.

Insertion. Into the inner part of the superior costa
of the scapula, and into the cartilage with which it is
tipped.

* It does not arise from the ribs, as some have described it.
PART II. r

66 Rhomboideiis Longus. — "Levator Humeri.

Use. To draw the scapula directly upwards, upon
the withers.

HUMERO-CEEVICAL REGION.

To guard against the multiplication of regions, I
have been induced to class the two following muscles
under this head.

Rhomboideus Longus.

A LONG tapering muscle, of a pyramidal figure, run-
ning along the side of the ligamentum subflavum. It
is hidden from view by some fibres of the panniculus.

Origin. Which is the apex of the pyramid, from the
side of the ligamentum subflavum, as high up as its
attachment to the second cervical vertebra — continuing
to arise from it in its course down the neck,, and in-
creasing in substance.

Insertion. Along with the rhomboideus brevis, into
the superior costa and cartilage of the scapula.

Use. To assist in the elevation of the scapula, and
to draw it at the same time forwards.

Levator Humeri.

A BKOAD muscle spread over the side of the neck.

Origin. By a thin tendinous expansion, high up,
from the tubercle of the occiput, and mastoid process of
the OS temporis ; from the transverse process of the
atlas, and those of the second, third, and fourth cer-
vical vertebrae ; and from the ligamentum subflavum,
and fascia of the neck. From these different origins
its fibres run obliquely downwards and backwards to
the point of the shoulder, over the head of the os humeri.

Muscles of the Neck.—Spleuius. 67

lO which they have a loose cellular attachment. It is
also similarly connected hereabouts to several of the
muscles of the shoulder, and blends its fibres with the
cen'ical portion of the panniculus.

Insertion. Into the fascia covering the muscles of
the scapula ; thence it is continued down to be fixed to
a ridge upon the body of the os humeri that proceeds
from its greater tubercle.

Use. To raise and draw forwards the shoulder, and,
vith it, the ami ; or, these parts being fixed, to titrii
he heLd and neck to one side. When both muscles
ict, they will depress the head.

It will be advantageous here to the dissector that I
; oceed with the dissection of the neck, leaving the re-
ions remaining to' be explored in the trunk, until I
ave described the muscles of the head. They are —
he pectoral, costal, sternal, dorsal, lumbar, and coccy-
cal regions.

Muscles of the Neck.

LATERAL CERVICAL REGION.

Having reflected from its points of origin the levator
umeri, we expose the

Splenius.

A vETtY large mass of muscle, constituting tlife^
lin thickness of the neck, the fibres whereof are tdk-
an oblique course from the ligamentum subflavum
' the cervical vertebrae. It is worthy of remark, that
ose fibres which approach the occiput are slender and
ie, while those at a distance from it are strong and
'arse. The whole muscle is invested in a thin ten-
nous fascia, which, in places, is so fii-mly adherent

F 2

68 Complexvs Major.

that it cannot be cleanly dissected off but with con-
siderable nicety.

Origin. By tendinous fibres — from which is sent
off its aponeurotic investment — and by fleshy ones, from
the ligamentum subflavum, as high up as the occiput,
and as far back as the fourth or fifth dorsal spine.

Insertion. By as many large fleshy packets, into the
transverse processes of the six lower cervical vertebrae ;
and by flat tendons, into that of the atlas, and into
the mastoid process of the temporal bone.

Use. To uphold the head and neck and to erect
them, when the pair act. One contracting alone, will
incline those parts to one side.

Complexus Major.

Between the splenius and ligamentum subflavum,
adhering to the latter by a fine cellular tissue, lies this
muscle, the largest of the neck. It is broad and bulky
upon the lower part of the neck, round and collected as
it approaches the occiput. Its fleshy fibres are inter-
sected in many places by narrow slips of tendon, and
are taking a different course from those of the splenius.

Origin. By short tendinous slips from the spines of
the four or five anterior dorsal vertebrae, and from their
transverse processes ; also from the transverse processes
of the lower five cervical. Its fasciculi run forwards
and upwards, congregating as they ascend, and end in
a flat tendon.

Insertion. Into the tubercle of the occiput, by the
side of the ligamentum subflavum.

Use. This is one of the most powerful pair of those
muscles that are — one or more of them — in continual
action to uphold the head and neck. It will, contract-

Complexus Minor. — Rectus Capitis Posticus Minor. 69

ing to its utmost, forcibly ei'ect the head, and, by pulling
the occiput backwards, produce that appearance called
the ewe neck. The splenius and it often co-operate ; but
the action of the former is more confined to the neck.

Complexus Minor.

A SMALL muscle contiguous to the ligamentum sub-
flavum, lying buried between it and the round or an-
terior portion of the major.

Origin. From the spinous process of the vertebra
dentata.

Insertion. Along with the complexus major, from
whose tendon its termination is inseparable.

Use. To assist that muscle in erecting the head.

Rectus Capitis Posticus Major.

A LARGER muscle than the former, underneath which
it is taking a similar course. It is attached to its fellow
by cellular membrane.

Origin. From the spine of the vertebra dentata.

InsertioTi. Into a scabrous pit in the occiput, below
its tubercle.

Use. To pull the head backwards, and, in doing so,
project the nose.

Rectus Capitis Posticus Minor,

Is placed immediately below the major.
Origin. From the upper pai-t of the body of the atlas.
Insertion. Along with the rectus major, into the
iicciput.

Use. To pull the head up quickly — the reverse of
nodding.

70 Obliquus Capitis Superior. — Spinalis Colli.

Obliquus Capitis Superior.

• A LITTLE higher up than, and to one side of, the
rectus major.

Origin. From the superior border of the transverse
process of the atlas.

" Imertion. Into a ridge extended from the tubercle
of the occiput.

Use. When both act, to assist in pulling up the
head : singly contracting, they will turn it to one side.

These four pairs of small muscles are principally em-
ployed in chucking up the head — as when a horse is
champing the bit, or annoyed by any irritation about
the head.

Obliquus Capitis Inferior.

A SQUARE thick muscle, situated above the former,
and much larger than it.

Origin. From the spine of the vertebra dentata.

Insertion. Into the superior parts of the transverse
process and body of the atlas.

Use. What little rotatory motion the head is capable
of, is effected chiefly by the single action of this pair
of muscles. When both contract, the atlas, and the
head with it, will be raised.

Spinalis Colli.

An oblong rounded muscle, interspersed with tendon,
closely applied along the roots of the ligamentum sub-
flavum.

Origin. From ike anterior oblique processes of all
the cervical vertebrae, except the first and second, and

Sterno-maxillaris.

71

from that of the first dorsal, by tendinous and fleshy
slips.

Insertion. Into the spines of all the cervical vertebrae
but the atlas.

Use. To aid in the elevation of the head, and to act,
both together, forcibly in the constrained flexion of the
neck backwards.

ANTERIOR CERVICAL REGION.

The muscles of this region are enveloped in a quan-
tity of loose cellular membrane, which must be cleanly
dissected off before they will appear distinct from one
another.

Stemo-maxillaris .

This pair of muscles lies subcutaneously along the
inferior and anterior parts of the neck. Near the sternum
they are in close approximation, and are so intimately
united, by fine cellular tissue, that much nicety in the
use of the scalpel is required to detach them up to their
place of origin. In proceeding upwards their union
becomes weaker, and they gradually recede from each
other, exposing, in the interspace, another pair of
muscles, which I shall have occasion to describe after
this. The sternal portion of this muscle is partially
"overed by a thin fleshy expansion — a portion of the
levator humeri.

Origin. Fleshy and tendinous, from the cartilage
projecting anteriorly from the sternum. Its belly is
compact, rounded, and of inconsiderable breadth in
comparison to its length. About three-fourths of its
length upwards, it terminates in a flat tendon, which
insinuates itself between the parotid and submaxillaiy
.rlands.

72 Sterm-lhijro-hyoidem.

Imertiov. By a fan-like expansion of its tendon,
into the angle of the posterior jaw.

Use. To inflex the head towards the chest. If one
act by itself, it will incline the head and neck to one
side. They will also assist the occipito-maxillaris in
opening the mouth.

Sterno-tliyro-hyoideus.

This is a trigastric muscle — having two fleshy bellies
superiorly, and one inferiorly, connected about the mid-
dle of the neck by a short slender tendon. The lower
portion is round and long, and is completely buried
between the sterno-maxillaris and trachea ; the upper
half, consisting of two bellies, is stronger, and is
further strengthened by the junction of a broad layer
of fleshy fibres, which originates from the levator
humeri, passes obliquely across, and proceeds with
this muscle to the head. These muscles may be said
to clothe the anterior and upper parts of the air-tube.

Origin. Fleshy and tendinous, from the anterior
cartilage of the sternum, above the place of attachment
' of the sterno-maxillaris. As they proceed upwards,
alongside of the trachea, they have weak cellular adhe-
sions to each other, and to those parts they run in
contact with.

Insertion. The main part of this muscle, having
crossed the front of the larynx, is inserted into the
neck or spur of the body of the os hyoides. A separate
slip, running between it and the trachea, and included
within the larger portion, is fixed by a short slender
tendon into the lower border of the thyroid cartilage.

Use. To draw the os hyoides, and larynx with it,
downwards and backwards.

Scalenus.— Rectus Capitis Anlicus Minor. 73

Scalenus.

A SHORT thick muscle, situated at the anterior and
inferior part of the neck, below the cervical portion of
the serratus magnus.

Oris^in. From the middle of the first rib.

Insertion. Into the bodies and transverse processes
of the fifth and sixth cervical vertebrae.

Use. To straighten the neck, by drawing the upper
part of it in a line with the lower. It is, in some
respects, an antagonist to the splenius.

*^* Immediutelj/ above this muscle, is a slender Jleshy
slip, running from the upper part of the first rib into the
belli/ of this : it might be denominated the scalenus posticus.

Rectus Capitis Anticus Major.

A LONG thin muscle that borders upon those remain-
ing to be described in this region, and extends from
where the scalenus ceases to be inserted to the occiput.

Origin. By slender fleshy fasciculi, infolding two or
three long slips of tendon, from the transverse processes
of the second, third, fourth, fifth, and sixth cervical
vertebrae. It first runs along the side of the neck,
liigher up it turns round under the transverse process
of the atlas, and there in part becomes tendinous.

Insertion. Fleshy and tendinous, into the cuneiform
process of the os occipitis.

Use. In co-operation with its fellow, to bend the
liead : by itself, it will also incline it to one side.

Rectus Capitis Anticus Minor.
•Sti i,L deeper than the rectus major, and just over it,
1 uns this small, entirely fleshy muscle.

74 Obliquus Capitis Anticus. — Longus Colli.

Origin. From the inferior part of the body of the atlas.
Insertion. With the foregoing.
Use. To assist the major.

Obliquus Capitis Anticus.

A DELICATE fleshy slip, placed a little more out-
wardly than the last-named muscle.

Origin. Close to the rectus minor, from the body of
the atlas.

Insertion. Into the point of the coronoid process of
the OS occipitis.

Use. To assist in flexing the head ; and, when one
acts alone, to incline it aside.

The three last-described muscles are antagonists
to the recti et obliqui capitis postici. In action, they
concur to produce that nodding motion of the head so
often seen in horses that are put on the bit : in which
case, the neck itself remains almost fixed.

Longus Colli.

This pair of muscles invests the inferior parts of the
bodies of all the cervical, excepting the atlas, and se-
veral of the anterior dorsal vertebrae. They are only in
places separable fi-om each other. They put on a
convoluted appearance externally, as if several small
muscles were blended together in their composition.
Their fleshy fasciculi, short and compact, are here and
there intersected by portions of tendon.

Origin. Inferiorly from the bodies of the six anterior
dorsal vertebrae.

Insertion. Into the bodies and transverse processes
of the six posterior cervical vertebrae, and, by a strong
tendon, into the body of the atlas.

Muscles of the Head. — Epicranius — Temporalis. 75

Use. The many and extensive attachments of this
muscle, and the proximity of its points of action, render
it one of considerable power and effect in the flexion of
the neck : the rainbow curve, the constrained incurva-
tion of the head towards the chest — as when a horse
is stretching himself — are chiefly ascribable to its full
and forcible contractions.

Muscles of the Head.

CKANIAL REGION.

There are but two that can be considered as cranial
muscles.

Epicranius.

The horse has two elevators of the upper eye-lid, and
this muscle, one of them, might with propriety, in rela-
tion to its function, be called the levator palpebrae supe-
rioris externus. It is a palish, slender, subcutaneous
muscle, obliquely placed upon that part of the frontal
lione which gives rise to the orbital process.

Origin. Almost imperceptible, so delicate are its pri-
mitive fibres, from an aponeurotic expansion over the
OS frontis, above the orbital arch.

Insertion. Into the upper eye-lid, nearer to its inner
than its outer angle ; in the substance of which its
fibres are blended with those of the orbicularis palpe-
Ijrarum.

Use. To raise the upper lid, and more particularly
the inward part of it.

Temporalis,

Occupies the side of the skull, and is demonstrable

76

Attollentes Aurem.

in the living horse. It is covered by a strong tendinous
fascia, that has a firm adherence to those bones from
w^hich the muscle arises.

Origin. From the parietal, occipital, and squamose
portion of the temporal bones ; and from the fascia
covering it. Its fibres, converging in their course, pass
obliquely downwards, under the zygomatic arch.

Insertion. Into the coronoid process of the lower jaw.

Use. To shut the mouth. It is a powerful agent in
manducation .

AURAL REGION.

In entering upon a description of these muscles, I
may briefly remark, that the concha is the cartilage that
gives shape and substance to the part of the ear which
projects from the head; that the sc?/^j/bnw or triangular
cartilage is a flat one, of three sides, loosely, and con-
sequently moveably, attached to the temporal muscle ;
and that the annular cartilage is a small ring-shaped one
that surrounds the root of the ear.

These muscles may be ranged in three divisions : —
the attollentes, the musculi proprii concha, and the re-
trahentes.

Attollentes Aurem,
Consist of four small muscles.

The Attollens Max imus is broad and thin, sub-
cutaneously spread over the forehead, and extended
from the vertex to the pit behind the orbit.

Origin. From the sagittal suture, along which it is
united to its fellow by the intervention of a tendinous
line ; from the tubercle of the os occipitis ; and from the
fascia temporalis by cellular substance. Its fibres pass

AttoUentes Aurem. 77

directly outwards, and converge a little as they approach
the ear.

Insertion. Into the entire upper border of the trian-
gular cartilage.

Attollens Minimus. Thus may be denominated
a fleshy slip which is detached from the middle of the
maximus. It crosses the triangular cartilage, and ter-
minates m an expanded form upon the inward part of
the concha, about one-third of its length upwards.

Attollens Inferior. Subcutaneously situated,
below the former, above and behind the orbit.

Origin. From the fascia temporalis, by cellular ad-
hesion. It grows broader in its course to the root of the
ear.

Insertion. Into the inferior part of the triangular
cartilage.

Attollens Superior is brought into view by the
reflection, from its origin, of the maximus, between
which and the temporalis it lies hidden.

O; •igin. From the sagittal suture. Its belly, .which
is nearly triangular, having reached the ear, makes a
turn to arrive at the posterior part of the concha.

Insertion. Into which it is inserted.

Use of the AttoUentes. These muscles all co-operate
in the erection or cocking of the ears. Acting in pairs,
the maximi or minimi will approximate them ; the
superiores will elevate them ; the inferiores, depress
them. But, as the triangular cartilage is more parti-
cularly their seat of action, in order to produce these
effects upon the concha, the aid of some smaller mus-
cles, next to be described, is necessarily called for.

78

M'usciili Proprii Condia,
Attach the triangular cartilage to the concha.

Anterior Conch;e arises from the outward sur-
face of the triangular cartilage, where its fibres are in-
corporated with those of the attollens inferior. It turns
round in front of the root of the ear.

Insertion. Into the anterior part of the concha, just
below its external opening.

^.KCTUS CoNCHiE. A Very small muscle, running
from the outward part of the triangular cartilage, near
its summit or apex, to the inward part of the concha.

Obliquus Concha arises close to the former, from
the upper extremity of the triangular cartilage. It
winds obliquely round to the fore part of the concha.

Iiisertiott. Into the concha, where its trumpet opens.

Internus Concha. The strongest of the conchal
muscles, lies concealed under the triangular cartilage.

Origin. From the inward surface of that cartilage.
It makes a turn to the posterior part of the concha.

Insertion. Into the very root of the concha.

Use of the Musculi Concha. The three first will as-
sist in the erection of the ears, and' present their trum-
pet-like apertures directly forwards, by drawing the
conchas round, and retaining them in close apposition'
with the triangular cartilages.

The internus will have directly the reverse operation
— it will rotate the ear, so that its open part may look
backwards, and collect sound from the rear : but it is
to be remarked, that still it is not a retractor, for it will
not depress the ears upon the poll.

79

Retrahentes Aurem.
These muscles are placed posteriorly.

Retrahens Superior arises from the ligamen-
um subflavum, near its implantation into the occiput.

Insertion. Running forwards and upwards, into the
lorsum of the concha, about one-third of its length up-
^ards.

Retrahens Inferior runs over the parotid gland.

Origin. Extensively from the gland, by very short
nd dense cellular membrane ; so much so that their
eparation is a nice and tedious dissection. It tapers
n its ascent to the ear.

Insertion. Into the outer margin of the concha.

Retrahens Medius, the largest of the retrahentes,
; placed between the two others, and is bifurcate at its
isertion.

Origin. From the occiput, ligamentum subflavum,
ad fascia of the neck.

Insertion. Of the superior portion, into the outward
)art of the concha, near its root ; of the inferior, into
he root of the concha, and into the annular cartilage.

Use of the Retrahentes. They are all employed in the
traction of the ears, and have, at the same time, a
iidency to rotate them, so as to turn their trumpets
■ ckwards. The superior has most effect in drawing the
ir down upon the back of the neck ; the inferior will

lightly abduct it, and present its. aperture outwards ;

lie medius, in lopping the ear, will turn its hollow,,

ide completely r»und.

80 Zygomaticus.— Retractor Labii Siiperiorh.

FACIAL REGION.

The muscles in this region are many, and some of
them complicated.

Zygomaticus.

A LONG slender superficial muscle, traversing the
cheek.

Origin. By glistening tendinous fibres, from the
lower edge of the zygomatic process of the os malae.

Insertion. Into the angle of the mouth.

Use. To extend this angle, by drawing it upwards
and backwards.

Levator Anguli Oris.
Superficially placed upon the fore part of the
cheek.

Origin. By a thin delicate tendon, from the side of
the OS nasi.

Insertion. In its course, which is obliquely down-
wards and backwards, it splits into two portions : the
inferior one grows smaller, and ends in the angle of the
mouth ; the superior disperses its fibres, from the angle,
upon the upper lip and the side of the nostril.

Use. To retract the angle of the mouth, assist in the
elevation of the upper lip, and dilate the nostril.

Retractor Labii Superioris.

Origin. By a thin cellular and tendinous expansion,
from the os maxillare superius, near its junction with the
OS malse. It grows broader in its descent, and passes
between the divisions of the preceding muscle.

Insertion. Into the side of the upper lip, and lower
part of the nostril.

Levator Labii Superioris. — Retractor Anguli Oris. 81

Use. To retract those parts ; and thus assist in rais-
ing the upper lip, and dilating the nostril.

Levator Labii Superioris.

A WELL-DEFINED muscle, of a pyramidal form,
distinctly prominent upon the anterior part of the face.

Origin. Fleshy, from a little below the inferior bor-
der of the orbit. Its round compact belly runs obliquely
forwards to the false nostrils, where a slender tendon is
sent off that adheres to those parts by cellular mem-
brane. Upon the extreme points of the ossa nasi it
unites with its fellow ; the two, then, form but one com-
mon tendon which dips into the middle of the upper lip.

Lisertion. Here it expands and expends itself among
the fibres of the orbicularis oris.

Use. To raise the upper lip, and dilate the false nos-
trils. If one only contract, the lip will be distorted,
and the false nostril of that side only enlarged. Their
action is well demonstrated in that peculiar corrugation
of the upper lip so remarkable in stallions.

Dilatator barium.

A SINGLE muscle of considerable thickness, seated
between the nostrils.

Origin. From the tapering extremities of the ossa
nasi, from which its fibres spread laterally.

Insertion. Into the alae of the nostrils, and upper lip.

Use. To raise the alae, and thus dilate the nostrils.

Retractor Anguli Oris.

Origin. Enveloped in loose cellular membrane,
from the lower border of the under jaw. It runs down-
wards and forwards.

PART 11, G

82 Retractor Labii Inferioris— Buccinator.

Insertion. Into the angle of the mouth, where its
fibres are intermingled mth those of other muscles.

Use. To draw the corner of the mouth upwards and
backwards.

Retractor Labii Inferioris.

A LONG slender muscle, running along the side of
the lower jaw.

Origin. From the ramus or branch of the posterior
maxilla, united with the buccinator.

Insertion. By a small round tendon, into the under
lip : having deeply penetrated its substance, it spreads
out into numerous in traceable fibres.

Use. To raise the under lip. If one act, it will be
elevated on one side only.

Buccinator.

That fleshy mass which fills up the space between
the upper and under jaws, and immediately invests the
membrane of the mouth. In order to obtain a full view
of it, it is necessary to cut away a part of the masseter.

Origin. Tendinous, from that part of the under jaw
between the last molar tooth and the root of the coro-
noid process ; fleshy, from the tuberosity of the supe-
rior maxillary bone, and from the outward borders of
the alveoli of the molar teeth. Its belly is composed of
two orders of fibres : those of the outer run transversely ;
those of the inner, for the most part, longitudinally.

Insertion. Into the buccal membrane, wherever it is
in contact with it, and into the angle of the mouth.

Use. To contract the cheeks, and retain the food,
during manducation, between the grinding teeth.

Orbicularis Oris. — Levator Labli Liferioris. 83

Orbicularis Oris.

Between those loose reflections of integument com-
posing the lips, is a mass of muscular fibres everywhere
intimately adherent to them, which, from their circular
course around these parts, may be described under this
name. Those muscles that are inserted into the lips
and corner of the mouth, may contribute to the pro-
duction of this ; but we may conclude, from their
course being different, that the generality of its fibres
are perfectly unconnected and distinct. It is stronger
in the upper lip than in the lower ; in both its fibres
are mingled with an unusual proportion of cellular
tissue, and embedded in adipose matter, including nu-
merous mucous follicles, blood-vessels, and nerves.

Use. To close the lips. The pi'ehensile power of the
lips, so well seen when a horse is gathering up scattered
grain from a plain surface, is owing to this muscle. In
pressing the lips hard against each other, it will also
have some effect in dilating the nostrils.

Depressor Labii Superioris.

By everting the upper lip, and carefully dissecting
off its cuticular lining, we bring into view, on either
side, a layer of pale fleshy fibres.

Origin. From the alveoli of the incisive teeth, and
side of the inferior maxillary bone.

Insertion. Into the upper lip, and ala of the nose.

Use. To depress the lip and project it forwards, and
to assist in dilating the nostrils.

Levator Labii Inferioris.
The situation of this muscle, in the under lip, is cor-
respondent to that of the preceding one.

G 2

84 Digastricus. |

Origin. From the alveoli of the incisive teeth, and
body of the lower jaw.

Insertion. Into the under lip.

Use. To raise the lip, and to project it forwards.

HYOIDEAL REGION*.

The subject having been turned, so that the head
rests upon the sinciput or forehead, in order to dissect
these muscles, the symphysis of the lower jaw ought to be
sawn through, and its branches carefully forced asunder.

Digastricus.

This muscle has not two bellies, but two tendons.
It is one of considerable length, and courses the side
of the jaw.

Origin. By a long slender tendon, which pierces the
fleshy belly of the stylo-maxillaris, from the styloid + pro-
cess of the OS occipitis. Leaving this muscle, in which
it has been concealed, the tendon passes between the
delicate tendons of the hyoideus, and then ends in a
round fleshy belly.

Insertion. By another tendon, which comes off" from
the opposite extremity of its fleshy part, into the side
of the jaw, inwardly, near to the symphysis.

Use. I am inclined to think that it is implicated in

* Prior to the dissection of these muscles, read the description of
the OS hyoides, given in Lecture xxxiii. . ^

-f As the muscles coming from this process correspond to those
to which in human anatomy the technical indicative stylo is pre-
fixed, it will be better, I think, to alter the name of the process than
apply new ones to the muscles. This was not adverted to in the
lecture on this bone, or it would not have been denominated the
coronoid process.

Mtflo-hyoideus. — Genio-hyoideus. — Hyoideus. 85

action with the hyoideus. It can have but feeble effect
in retracting or depressing the jaw.

Mylo-hyoideiis .

This is a broad thin muscle of the penniform class,
that spreads out between the branches of the jaw, and
with its fellow forms a sort of bed for the tongue and
muscles of the glossal region.

Origin. From the side and alveolar process of the
jaw. Its superior fibres are stronger than those below.

Insertion. Into the body of the os hyoides. It is
united to its fellow by a white tendinous line.

Use. To draw that bone forwards and upwards, and
to raise the tongue in the mouth.

Along its middle it is connected to the

Genio- hyoideus,

Round and compact, lies immediately above the
last, and is so intimately united with its fellow that the
two appear to be but one muscle.

Origin. By a flat tendon, from the posterior jaw,
near its symphysis.

Insertion. Tendinous and fleshy, into the spur-like
process of the os hyoides.

Use. To assist the former in advancing and raising
the OS hyoides.

When the os hyoides is fixed, the two last-named
muscles will assist in opening the mouth.

Hyoideus.

Exclusively attached to the os hyoides.

Origin. By a small round tendon, from the broad or

86 Genio-hyo-glossus. — Hyo-glossus Longus.

posterior part of the cornu. Its belly is partially split
into two, from which proceed two separate tendons ;
these together form a sort of loop that includes one of
the tendons of the digastricus.

Insertion. In two places, into the side of the body
of the OS hyoides.

Use. To pull this part of the bone nearer to the jaw,
and thus contribute to the dilatation of the glottis.

GLOSSAL REGION.

These muscles, by their union with one another, com-
pose that fleshy body called the tongue : their number
and variety account for its extreme self-mobility.

Genio-hyo-glossus,

Of considerable breadth, spread out in the form of
a fan, and placed immediately above the genio-hyoideus.

Origin. Tendinous and fleshy, from the inward part
of the jaw, near the symphysis, in company with the
genio-hyoideus. Its tendon reaches for some way
along its inferior border.

Insertion. Some of its fleshy fibres run as far back-
wards as, and have an attachment to, the appendix and
body of the os hyoides ; but the bulk of them take
their course obliquely upwards to be implanted into the
whole length of the tongue.

Use. To project the tongue in the mouth, and draw
it downwards : if one only act, it will be pulled to
one side.

Hyo-glossus Loiigus,
Forms the lateral part of the tongue.

Hyo-glossus Brevis. — Lingualis. 87

^ Origin. By a thin weak tendon, from a little tubercle
upon the cornu of the os hyoides .

Insertion. Into the lateral and inferior parts of the
tongue, vanishing in its tip.

Use. To draw the tongue within the mouth, and
depress it.

Hyo-glossus Brevis.

Origin. From the lateral part of the body of the
OS hyoides. It grows broader during its course, and is
entirely fleshy in substance.

Insertion. Into the base of the tongue, which it
penetrates.

Use. To assist the former in the refraction of the
tongue, and to depress the base of it.

Lingualis.

The interior of the tongue consists of a fleshy mass,
the fibres of which run in various directions, and have*
as their connecting medium, a considerable quantity of
adipose membrane : this is generally regarded as a dis-
tinct pair of muscles, and called the linguales. They
may be said to arise from the root of the tongue, and
to terminate in its point. They receive the insertions
of all the other muscles.

Use. To contract the tongue lengthwise, and to
draw it within the mouth.

MAXILLARY RE9ION.

The next to be described are three short thick
muscles, of great united power, which are inserted into
' the lower jaw.

88 Masseter. — Stylo-maxillaris. — Pterygoideus .

Masseter.

A PAIR of strong well-defined muscles which out-
wardly constitute the cheeks : in well-formed, thorough-
bred horses, they add much, by their prominence, to
the beauty of the head.

The masseter is covered by a strong tendinous fascia
from which its fleshy fibres are inseparable ; many tendi-
nous septa proceed from it, which intersect the fleshy
substance, and split it into several distinct layers of fibres.

Origin. From the under part of the zygomatic arch,
and from the superior maxillary bone. Its fibres pass
obliquely downwards and backwards upon the side and
branch of the jaw.

Insertion. Into the rough border around the angle of
the jaw.

Use. To act, in conjunction with the temporalis, in
the eleyation of the jaw.

Stylo-maxillaris .

A ROUND, compact muscle, found above and behind
the jaw, the fleshy fibres of which are strongly knitted
together by tendinous interlacements.

Origin. From the styloid * process of the os occipitis.

Insertion. Broader than its origin, into the angle of
the jaw.

Use. To pull the jaw backwards and depress it. It
is an antagonist of the masseter and temporalis.

Pterygoideus.

This and the next muscle occupy the smooth exca-

* Olim coronoid.

Hyo-Tharyngeus. — Palato-PJiaryngeus. 89

vated part of the branch of the jaw : they take the
same course upon its inward part to what the masseter
does outwardly.

Origin. At the base of the cranium, tendinous and
fleshy, from the aUform or pterygoid process, and crus
of the OS sphenoides, and from the os palati.

Insertion. By spreading and divergent fleshy fibres,
intersected by layers of tendon, extensively into the
branch, side, and angle of the jaw.

Use. To close the jaws. If only one contract, the
jaw will, in being shut, be drawn a little to one side.
Their alternate action will produce that lateral motion of
the jaw which is so effectual in comminuting the food.

PHARYNGEAL REGION,

Comprehends six pairs of small muscles belong-
ing to the pharynx.

Hyo-Pharyngeus.

Origin. Very near the broad or posterior part of the
cornu of the os hyoides.

Insertion. Into the side of the pharynx.

Use. To dilate this bag, for the reception of the food.

Palato-Pharyngeus.

Origin. From that part of the os palati which pro-
jects downwards into the cavity of the mouth.

Insertion. By an expanded termination, meeting
that of the next muscle, into the side of the pharynx.

Use. Though acting in a contrary direction to the
muscle above, it will assist in dilating the pharynx.

90

Stylo-pJiaiyngeiis.

Origin. By means of a thin membrano-tendinous
substance, from the styloid process of the os temporis.
Insertion. Into the side of the pharynx. •
Use. To pull it, in a direction, upwards and back-
wards, and thus assist in its dilatation *.

* The remaining muscles in this region —the constrktores pha-
ryngis — will be given with the description of the pharynx.

LECTURE XXVIII.

^ ^s«s^ yvs^

X SHALL now return to the

Muscles of the Trunk.

PECTOKAL REGION.

The pectoral muscles constitute the breast, or, what
s vulgarly and absurdly often called, the bosom of the
inimal.

Pectoralis Transversus *,

Upon the under and fore part of the breast, it
;akes its course transversely to the arm. In full-
breasted horses, this pair of muscles form two remark-
ible prominences in front of the chest, extending back-
wards between the fore legs.

Origin. When first exposed, it appears to arise from
its fellow of the other side, but further dissection will
show a white tendinous line, by means of which it is
taking its origin from the four first bones of the sternum.
Its belly, which is broad, and thicker anteriorly than
posteriorly, runs directly across to the inward part of
the arm.

Insertion. Into the fascia of the arm, extending from
the olecranon nearly half-way down to the knee.

Use. To confine the arm to the side in its motions

* Primus, Antictts, vel Brevis.

92 Pectoralis Magnus. — Pectoralis Parvus.

forwards and backwards, and to prevent that movement
which, in common equestrian language, is called " all
abroad." So far as the fore limbs do admit of abduc-
tion and adduction, which we have the best example of
in that mode of going taught horses in riding-schools,
termed passage, this muscle will act as a powerful ad-,
ductor.

Pectoralis Magnus*,

Placed behind and above the former muscle ; which
must be removed in order to obtain a full view of it.

Origin. From the fourth, fifth, and sixth pieces of
the sternum, from the cartilages connecting them, and
from the ensiform cartilage, where, through the inter-
vention of a white tendinous line, it is united with its
fellow ; also from the aponeurosis of the external oblique
muscle, and from the cartilages of the false ribs, several
of which are concealed by it. From these attachments,
its fasciculi approach one another and unite into a long}
flattened belly, which runs forwards, inclining rather
upwards, upon the true ribs.

Insertion. Into the lesser tubercle of the os humeri,
and inward part of the lower end of the scapula.

Use. To pull the humerus, or more properly the
point of the shoulder, backwards — drawing the scapula
upright.

Pectoralis Parvus f,

A MUSCLE of less size than the preceding, along tlie
anterior border of which it is taking a similar course.

Origin. Tendinous, from the inferior and projecting
part of the sternum, where it is united with its fellow ;

* Secmuiwi, posticus, vel longus.

t Vcl Depressor scapula:.

Serratus Magnus. 93

V6m the anterior cartilage of the bone ; and from its
side. The belly of this muscle is round, and rather
thicker than that of the magnus.

Insertion. Into the fascia covering the muscles upon
the anterior part of the scapula and shoulder-joint,
extending nearly as high up as the place of origin of the
•antea-spinatus.

Use. To assist the pectoralis magnus.

COSTAL REGION.

These muscles are all extensively attached to the ribs.

Serratus Magnus.

I MAY here remark, that, although the epithet magnus
is mostly applied to this muscle, there is no serratus
parvus vel minor. It is the connecting medium between
the ribs and the blade bone, and is in a great measure
hidden from view by the latter. In carrying our eye
around the circumferent points of origin of the serratus,
we shall find that it bears some approach in figure to a
semicircle, of which its insertion is the centre.

Origin. Very extensive, from the bodies and trans-
verse processes of the fourth, fifth, sixth, and seventh
cervical vertebrae ; and from the eight anterior true ribs,
as low down as their cartilages, by as many fleshy di-
i^itations. The cervical portion is of considerable thick-
ness ; its fasciculi, and those coming from the chest,
all converge towards a central point.

Insertion. By collected strong fasciculi, tendinous
as well as fleshy, into the upper and inward part of the
scapula — from the place of origin of the subscapularis
to that of the insertion of the rhomboidei.

94 Serratus Magnus.

Use. This constitutes the main attachment of the
scapula to the trunk — cut the serrati through, and the
fore limbs can no longer sustaiia their burden.

I stated, in my lectures on osteology, that there
existed no joints between the trunk and fore extremi-
ties ; so that half the trunk and the head and neck are
actually in a state of suspension ; and muscles, and
above all the seirati, are the suspensary agents. From
their functions being so laborious and important, then,
we find that every advantage is afforded to enable
them to act with power superior to that of most other
muscles in the body. Their fleshy fasciculi are thick,
red, and strong ; their fibres have but little tendinous
inter-texture; their attachments are broad and exten-
sive; and their points of origin and insertion are con-
tiguous to one another.

Moreover, the serrati are more or less concerned in
all the motions of the scapulae. From the great variety
in the course of their fibres, they will move these bones
forwards, or backwards, or downwards ; so that we
must regard them as powerful co-operators in the
actions of the shoulder.

If the fore extremities be made fixed points, and
especially if they be abducted a little, the serrati, by
drawing the ribs towards the blade bones, become also
powerfiil muscles of inspiration. This explains why
horses, whose respiration is hurried or embarrassed,
stand with their fore legs stretched apart, and why those
labouring under pneumonia, seldom or never lie down.
I apprehend, however, that they are not employed in
ordinary, undisturbed breathing.

The scapula, in this stage of the dissection, should
be detached from the trunk.

Superficialis Costarum. — Transversalis Costarum. 95

Superjicialis Costamm,

Consists of a thin fascial expansion, terminating in,
and interlaced with, a broad palish layer of fleshy fibres.
This fascia invests the muscles contained in the dorsal
region.

Origin. By tendinous fascia, from the ligamentum
subflavum, in its extension through the back and
loins.

Insertion. By fleshy and tendinous slips, into the most
curved or prominent parts of the ribs, near their middles.
Use. To elevate the ribs, and thus dilate the thorax.

Transversalis Costarum.

Underneath the fleshy part of the superficialis
lies this muscle. It takes its course transversely along
the upper part of the chest, extending from the first
rib to the last. It is remarkable for the number and
regularity of its tendons, which pass off, after the penni-
form manner, from the inferior border of its belly, in-
creasing in length, but growing narrower, as they ap-
proach the last rib.

Origin. By a strong tendon, from the transverse
process of the last cervical vertebra.

Insertion. Into the superior parts of the ribs, at a
distance from the spine, growing greater from the first
to the last rib : its tendons are only fixed into their
posterior edges.

Use. The vertebra being fixed points, and the two or
three anterior ribs nearly so, it will pull the angles of
the others forwards, and so assist in the dilatation of
the thorax.

96 Intercostaks Externi Sf Interni. — Lateralis Stei-ni.

Intercostales Externi.

Regular courses of fleshy fibres, exteriorly striped
with thin slips of tendon, Mvhich run from the posterior
sharp edge of the rib before to the anterior rounded
border of that behind. They are discontinued between
the cartilages ; the interstices there being occupied by
the sterno-costales externi. Superiorly, at the angles,
they are continuous with the levatores costarum.

Intercostales Interni.

Layers of fleshy fibres, interspersed with thin ten-
dinous bands, covered by the externi, to which they
are similar in their attachments, but contrary in course :
they decussate each other, in fact, like the strokes
of a cross — X.

Use. These muscles act from the anterior, upon the
posterior ribs; which they pull forwards and have a
tendency to throw outwards ; and thus enlarge the
cavity of the chest.

STERNAL REGION,

CoMPREHEND's two Small musclcs that are attached
to the outward surface of the sternum.

Lateralis Sterni,

A SMALL semi -tendinous band of muscle.

Origin. From the first rib, near its cartilage.

Insertion. Into the cartilages of the three or four
anterior ribs, and into the sternum.

Use. To raise the sternum, and contract the cartilages,
and thus diminish the thoracic cavity.

Sterno-Costales Externi.—Longissimm Dorsi. 97

Sterno-Costales Extemi.

Several fleshy digitations, interspersed with slips
of tendon, which are running from the cartilages of
all the true ribs, excepting that of the first, to the ster-
num. Their fibres take the same course, and are con-
tinuous in the spaces between the cartilages, with the
intercostales extemi.

Use. Also employed in the contraction of the chest.

DORSAL REGION.

These muscles are connected with the vertebrae of
the back.

Lorigissimm Dorsi.

Above the transversalis costarum runs this, one of the
largest and longest muscles in the body. The posterior
portion of it, which extends as far back as the ileum, is in-
vested by a strong aponeurotic substance that gives ori-
gin to numbers of its largest fasciculi. In proceeding
forwards upon the muscle, this fascial investment grows
thin, cellular, and weak, detaching processes from the
inward surface which enter and intermingle with its
leshy fibres : it vanishes, previous to the termination of
he longissimus, among the muscles of the neck.

Origin. Tendinous and fleshy, from the crista of the
ileum, from the spinous and transverse processes of
ill the lumbar vertebrae, and from the spinous processes

the six posterior dorsal.

hmrtion. By coarse fleshy fasciculi, which take
their course downwards as well as forwards, poste-
■iorly into the angles of the twelve last ribs ; by a

PART 11. H

98 Spinalis Dorsi.—Semi-spinalis Dorsi.

regular series of tendons, concealed in its fleshy part,
into the transverse processes of all the dorsal ver-
tebrae, and into those of the three or four hindermost
cervical.

- Use. This is a muscle of great power and extent of
action. The motions of the spine, in the back and
loins, are mainly produced by it. It will incline the
fore quarters upon the hind, or the hind upon the fore,
as these or those are made fixed points. It is a prin-
cipal agent in kicking and rearing. If one act alone,
the fore or hind parts will be carried to one side. The
pair will also assist in the erection of the neck.

Spinalis Dorsi

Lies upon the anterior portion of the longissimus
dorsi, of which some consider it a part.

Origin. It begins tapering upon the aponeurotic
covering of that muscle, and may be said to arise,
through the intervention of it, from the spinous pro-
cesses of several of the posterior dorsal vertebrae. It
rapidly increases in substance, grows thick, round, and
partly tendinous in its course, and closely embraces the
withers as it proceeds to the neck.

Insertion. Into the spines of the six or seven anterior
dorsal vertebrae, and those of the three or four posterior
cervical.

Use. To writhe the back, or bend the withers, and to
assist the longissimus dorsi in erecting the neck.

Semi-spinalis Dorsi

" Is composed of several packets of fleshy fibres, pretty
regularly intersected by portions of tendon which are
broadest and most remarkable at its anterior part.

Levatores Costarum. — Semi-spinalis Liimborum. 99

Origin. From the transverse processes of the dorsal
vertebrae. Its fibres run in a slanting direction for-
wards and upwards, and clothe the lateral and superior
parts of these vertebrae, from the first to the last.

Insertion. Into the dorsal spines, receding from
their tops as it proceeds forwards.

Use. To incline the spines backwards, and tend to
pull one over the other. It co-operates with the Ion-
Li issimus dorsi.

Levatores Costarum.

Little prominent bundles of fleshy fibres, about fif-
teen in number, which take a similar course to the inter-
costales externi : indeed, they appear to be conti-
nuations of those muscles to the dorsal vertebrae.

Origin. By fleshy fibres, infolding small tendons,
f rom the transverse processes of the dorsal vertebrae.

Insertion. By fleshy fibres, impacted in tendinous
coverings, into the anterior edges of the ribs, in the
spaces between their tubercles and angles.

Use. To assist the intercostales, and contribute a
little to the elevation of the ribs.

LUMBAR REGION.

Of these muscles two are placed externally, and four
nternally— opposed to the abdominal viscera. External.

Semi-spinalis Lumborum

Is constituted of regular layers of fleshy fibres, sirai-
arly distributed in the loins to what those of the semi-
.pinalis dorsi are in the back, whence they are conti-
nued to the sacrum. They are covered by a thin ten-

H 2

100 Intertransversales Lumborum. — Sacro-Lntmbalis.

dinous expansion, stretched from transverse to spinous
process. In their attachments and use, they correspond
to those of the back.

Litertransversales Lumborum.

Small muscles rmining from the sharp edge of one
transverse process to that of the one next to it. They
are included between two strong and tense intertrans-
verse ligaments.

Use. To approximate these processes.

The subject should now be turned upon its back in
order to dissect the muscles that are internal.

Sacro- Lumbalis.'

Thus maybe named a thin layer of disgregated fibres
which traverses the under surface of the loins. Some
are taking a straight line ; others, a semi-circular
course ; others, again, decussate one another.

Origin. From the most anterior and lateral part of .
the body of the sacrum, and from the transverse process
of the last lumbar vertebra.

Lisertion. Into the other transverse processes of the
loins ; and, of some few of its fibres, into the last rib.

Use. To co-operate with the intertransversales lum-
borum in approaching the transverse processes, and
to fix the last rib.

Psoas Magnus

Ru N s along the under part of the loins, above the
kidney, covered by a strong tendinous aponeurosis. The
psoae constitute the inner part of a sirloin of beef, which
at table is often preferred for its exceeding tenderness :

Psoas Magnus. — Psoas Parvus. 101

this may be accounted for by their fibres being finer
than those of most other large muscles, and by their
function being comparatively hght.

Origin. From the inward surfaces of the two last
ribs, close to their articulations with the vertebrae ; and
from the bodies and transverse processes of the last dorsal
vertebra, and all the lumbar vertebrae. In its passage
to the thigh, some of its fibres are blended with those
of the iliacus.

Insertion*. By a flat tendon, into the brochanter
minor internus.

Use. To bend the femur upon the pelvis — to pull
the haunch forwards in progression. When the hind
quarters are fixed, it will produce that flexure of the
spine which constitutes the roach back, vulgarly called
" sticking up the back."

Psoas Parvus.

A SMALLER muscle than the last, placed between it
md the spine.

Origin. From the heads of the sixteenth, seven-
ccnth, and eighteenth ribs, from the bodies of the three
)Osterior dorsal, and from those of all the lumbar
vertebrae.

Insertion. By a thin flattened tendon, into a rough
•urface upon the os innominatum, below the acetabulum.

Use. To draw the pelvis forwards. When one acts, it
[lay incline it to one side. The pelvis being fixed, this
auscle will assist the psoas magnus in arching the spine.

* The search, with the knife, after the insertion of this muscle,
iiul that of the two following, had hetter be deferred until the
luiscles of the hind extremity shall have been dissected.

102

Iliacus. — Di aphragm .

Iliacus *,

A MUSCLE of considerable substance and power, placed
above and in part exterior to the psoas magnus.

Origin. From that part of the crista of the ileum that
has no bearing upon the sacrum ; and from the anterior
spinous process, venter, and inferior edge of the bone.

Insertion. It is continued down to the thigh in com-
pany with the psoas magnus, with which it is inserted.

Use. To advance the haunch.

INTERNAL COSTAL REGION.

Though one of these muscles might with propriety
have been included in the sternal region, and the other
considered with equal justness as within the cavity of
the abdomen, I have ventured to class them both together
in this region for the convenience of dissection.

Diaphragm.

The diaphragm is that fleshy and tendinous par-
tition which divides the cavity of the chest from that of
the abdomen. In the dead subject it is convex before
and concave behind, which shape it assumes in conse-
quence of the last effort of life being an act of expira-
tion. Its convex part is covered by pleura, its concave
by peritoneum. It may be divided into its body, and
its appendices or crura : the first comprehends that por-
tion which is the veritable muscular fence ; the last,
some fleshy slips that run from it along the spine within
the cavity of the belly.

* Sometimes called Iliacus Intemus ; but the epithet is supe-
rerogatory. , :

Diaphragm. 103

Origin. The body, sometimes called " the greater
muscle of the diaphragm," arises by fleshy digitations
from the cartilages of the eighth, and those of all the
posterior ribs, with the exception of the two last; also
from the cartilago ensiformis. From these points of
attachment, they converge like the radii of a circle, and
terminate, about midway between the ribs and the spine,
in a thin expansion of tendon, which has received the
name of the cordiform tendon.

The crura, or appendices of this muscle, are two in num-
ber, and lie by the sides of the aorta — which vessel takes
its course between them : the right, much the longer
of the two, arises, above that artery, from the inferior
part of the bodies of all the lumbar vertebrae ; the left or
shorter has a tendinous origin from the under part of
the body of the first lumbar vertebra, and by a separate
tendinous slip from that of the second. They unite
and decussate each other opposite to the seventeenth
dorsal vertebra, form a fleshy belly, and this again
splits into two portions previously to its insertion, in
order to admit of the passage of the esophogus.

Insertion. Into the upper part of the cordiform
t endon. About the centre of this tendon is a perfora-
tion for the passage of the vena cava posterior ; so that
there are altogether three openings in the diaphragm: —
an uppermost one between the crura for the aorta ;
another or lowermost, formed by the decussation of the
crura, for the esophogus ; and a third in the centre of
its tendon for the vena cava.

Use. The diaphragm is the principal, if not the sole,
agent of ordinary inspiration : it acts in respiration in
ipposition to the abdominal muscles, which are the chief
xpiratory muscular powers. By the contraction of its

104 Sterno-Costalis Intemus. — Retractor Ani^

radiated fibres, aided by that of its crura, the cordiform
tendon is reduced to a plane, and the dimensions of the
chest thereby considerably augmented from before back-
wards ; after which, its thoracic surface is rendered again
convex, and its abdominal concave, by a general re-
laxation of its fibres, and the concomitant pressure of
the viscera of the abdomen, in consequence of the re-
action of the abdominal muscles. The diaphragm, how-
ever, may be made to act simultaneously with the abdo-
minal muscles ; as happens in the expulsion of fcecal
matters, and of the foetus.

Stemo-Costalis Intemus.

This muscle lines the sternum inwardly: it is inter-
posed between it and the cartilages of the ribs, and
the pleura.

Origin. By tendinous roots, from the upper half of
the sternum.

Insertion. Having become for the most part fleshy,
and considerably thicker, into the cartilages of the
true ribs.

Use. By pulling the ribs downwards and backwards
to contract the cavity of the chest.

ANAL REGION,

Includes a pair of muscles, and a single one.

Retractor Ani.

A PAIR of small, fleshy muscles, which emerge from
the outlet of the pelvis.

Origin. From the sacro-sciatic ligament, and from
the ileum and ischium, where they unite to form the

Sphincter Am. 105

acetabulum. Its fibres run upwards and backwards,
and intermix with those of the sphincter ani.

Insertion. Into the side of the anus.

Use. To retract the anus — draw it within the pelvis.

Sphincter Ani.

The prominence of the anus consists chiefly of adi-
pose matter ; but, by carefully removing this, we shall
find that it is partly composed of the muscle now under
consideration.

Red bands of fleshy fibres surround the rectum as it
terminates in the anus ; indeed, they may be said to
suspend it, for they are firmly attached above to the
base of the coccyx, whence they proceed laterally upon
the gut, and coalesce around its middle.

Use. To close the anus, after the expulsion of the
foeces.

COCCYGEAL REGION.

Since an anatomical knowledge of these muscles is
indispensable to the scientific performance of an opera-
tion that is often required of the veterinary practitioner —
jiicking — I shall dwell the more upon my description of
them. In denuding them, it will be found that the skin
is soft and thin upon the under part of the tail, where
there is no hair, and that it grows thick and coarse as it
approaches the tip : it is also more closely adherent to
the muscle at that part, there being less cellular sub-
stance interposed. These muscles are divisible into
four pairs, and most distinctly so near their origins :
upon the coccyx their nearest fibres unite and blend
with one another.

106 Erector Coccygis. — Depressor Coccygis.

Erector Coccygis.

A PAIR of long pyramidal muscles, remarkable for
their tendinous appearance externally, that form the
upper and lateral parts of the dock.

Origin. It begins upon the croup, by attachments
tendinous and fleshy to the transverse processes and
spines of the sacrum, lying in a hollow between that
bone and the posterior or bearing part of the ileum,
and the ilio-sacral ligament. The muscle, when formed,
is complex in its composition — consisting exteriorly of
a flat tendon from which slips are detached in its course
along the tail in a penniform manner over the belly of
it, and of an interior or fleshy part which, diminishing in
size and growing paler in its descent, closely adheres
to the bone itself.

Insertion. Into the bodies and spines of the ossa
coccygis. The insertion is chiefly fleshy ; but here and
there slips of tendon pierce its belly and take root in
the bone. Its tendons, though they become very small
about the extremity of the dock, there predominate so
much over its fleshy fibres, that it is only by means of
them that we can distinctly trace the muscle to its ter-
mination.

Use, To elevate the tail. If one only contract, it
will also be carried to one side. Some horses can exert
so much action with these muscles, that they can reflex
the tail over the back, or curl it to either side, around
the quarter.

Depressor Coccygis

Takes its course along the under part of the tail, in
a similar manner to what the preceding muscle does

Depressor Coccygis. 107

upon the upper, of whicli it is the antagonist. Like it
also it has externally a flat tendon ; but this is much
smaller, and does not detach any lateral slips until it
has descended to near the middle of the coccyx. Its
fleshy belly, on the whole, is more bulky ; and conse-
quently we may regard it as a muscle of more living
power than the last; but it certainly possesses less
mechanical strength in the dead subject.

Origin. Within the pelvis, from the sacro-sciatic
ligament, and from the body of the sacrum. It grows
smaller as it passes out of the pelvis, and forms a
rounded prominence upon the under part of the coccyx.

Insertion. By strong and separate tendons, which
issue from that traversing its middle, and are concealed
in its fleshy belly, into the inferior parts of the bodies
of the ossa coccygis. Its tendons increase in number,
but diminish in size, as they descend * ; and near the
tip surpass in strength those of the erector. If a section
is made of any part of this muscle, always two, and
sometimes three or more of its tendons are severed : in
nicking, the principal one generally projects within
the section, and a portion of it is then excised.

Use. To depress the tail. If one alone is in action —
in which case it may co-operate with one of the erectores
— to incline it to one side : this is remarkable very often
at the time that a mare is taking the horse. The power
of these muscles can in no mode be better estimated
than by attempting to raise the docks of horses that are
" shy about the tail :" not infrequently does it de-
mand the whole force of a strong arm to effect it, and

* So that the further from the anus the incisions arc made in
nicking, the fewer tendons arc divided.

108 Cnrvator Cocci/gis. — ()« Nidnng.

now and then the efforts of the animal cannot be over-
come but by both hands.

Cwvator Coccygis

Is a smaller muscle than either of them already de-
scribed, between which it takes its course ; but it bears
a close similarity to them in the appearance and dispo-
sition of its fibres.

Origin. Within the pelvis, from the lateral parts of
the sacrum, and commonly from the fourth and fifth
lumbar vertebrae. Here it consists of two parts, which
have been regarded as distinct muscles : the one ac-
companies the erector, the other the depressor coccygis.

Insertion. By tendinous and fleshy productions, in-
timately and inseparably interwoven, into the transverse
processes of all the ossa coccygis.

Use. To incurvate the tail, or laterally flex it
around the quarters. In switching off flies with the
tail, these muscles, aided by others, are thrown into
action to lash the hair forwards.

Compressor Coccygis.

A BBC AD, flat muscle, which largely contributes to
the formation of the root of the tail.
' Origin. From the sacro-sciatic ligament, and from
the ischium.

Insertion. Into the transverse processes of the four
or five uppermost bones of the coccyx.

Use. To assist in depressing the tail, and to main-
tain it forcibly pressed against the anus.

On Nicking.

Nicking is one of those operations which fanciful

0«. Nicking. 109

art has had the presumption to invent for the iraprove-
nient of nature. The arguments in favor of it are all
grounded on what we regard as perfective of configu-
ration ; those against it may dispute that ground, and
receive additional weight on the score of cruelty. It re-
quires little or no argument to defend an act that carries
with it corporeal sufferance, however severe, providing
that act be undertaken to ward off or remedy an evil
greater than the pain itself, as is the case in neurotomy ;
but it demands sober and deep reflection before we
attempt to reply to all the animadversions that may be
cast at us against the infliction of pain, acute and en-
during, for the sake of improving the symmetry of an
animal that may, by some, be regarded as already per-
fect. It is not with a view of decrying nicking that
I make these observations ; but it is to show them who
are not of the profession, into whose hands these lec-
tures may fall, that veterinary practitioners, however
much it is their own interest, and their duty to their
1 mployers, to perform them, are not insensible to the
suiferings they inflict by such operations, and conse-
quently take all means, it is to be hoped, in their power
to mitigate and abridge them.

Nicking consists in a surgical operation, the object
of which is, to compel a horse to carry the tail erect.
In order to obtain a physiological view of this operation, it
will be necessary to revert to the actions of those muscles
that raise and fall the tail. We must bear in mind that
the depressors, in consequence of being in themselves
larger than the erectors, and of having less tendon in their
( omposition, are capable of overpowering their antago-
nists ; and we must understand that these are voluntary
muscles, and consequently that no other than artifi-

110 On Nicking.

uial means, unless this balance of power be in favor
of the erectors, can compel the animal to carry the tail
erect. The application of mechanical means of any
description could not fail to defeat, in part at least, the
design for which they were used ; for it is hardly con-
ceivable that any thing, answering this purpose, could
be contrived that would not be more or less unsightly :
it naturally became a question therefore, and an im-
portant one with those who were admirers of the high
tail, how the power of elevation might be made to pre-
dominate. What first gave rise to nicking — whether it
was the result of accident — the groundless experiment
of some unscientific equestrian — or the offspring of
physiological reasoning — and how long it has been
known and practised, I neither know, nor am about to
inquire : it will be sufficient for us to understand the
theory of the operation, and the principles on which it
is, or ought to be, conducted.

If a complete section be made of a muscle, and
the divided parts be allowed to approach each other,
or be maintained in constant apposition, intimate
union by adhesion will follow, and the muscle sus-
tain little or no permanent injury from it, either in
structure or in function ; but if the disunited portions
be kept apart from each other, so that adhesive matter
fill up the vacuity, a loss of power will result, propor-
tionate to the extent of this interposition. There are
two reasons why an operation of this description should
be productive of such effects. When the fibres of a
muscle are first divided, they naturally shrink or
contract from so sharp a stimulus as the knife ; and,
luiless means be used to bring them together again, a-
gap is left, into which is effused, in consequence of the

On Nicking. Ill

inflammation excited by the injury, a quantity of adhe-
sive matter ; a substance, that, although it undergoes
an entire change in the course of time, is never con-
verted into muscular fibre : so that not only the fasci-
culi of the muscle shorten themselves under the knife,
and in course are not susceptible of their wonted con-
traction afterwards, but the albuminous interposition ob-
structs that elongation which is a necessary preparative
to a full and natural contraction. Thus, then, is the
original structure of the muscle broken in upon, and
thus is its action in consequence impaired, and the ba-
lance of power transferred to the erectors.

Though nicking is undertaken at all seasons of the
year, they are unquestionably the most favorable dur-
mg which neither frosts nor flies are likely to disturb the
healing process. Prior to entering upon the operation,
when we have the sole management of the subject, it is
advisable to feed on bran mashes for a few days, and
exhibit a little laxative medicine : the old practice of ad-
ministering a dose of aloes on the day of operating is
worthy of being followed when no preparatory regimen
has been observed.

The operation itself, like most others that employ
the veterinary surgeon, is simple in its nature and easily
performed : I might, indeed, without much overstrain-
ing this point, regard it as purely a mechanical one;
for there are but few horse-dealers or head-grooms who
are not au fait at it, which is at least a practical de-
monstration that a little manual dexterity and expe-
rience will bear the operator out ; for I do not imagine
that these gentry will contend for any anatomical know-
ledge ! The distinction lies here, as it does in all such
cases, between the man of science and the man of no

112 On Nicking.

science, in this — that the one is prepared to encounter
any unusual appearance, or accident, that may present
itself during the operation, and to combat any ill that
may result from it ; whereas the other is baffled, perplex-
ed, and alarmed at such an event, and is as unfit to
treat the morbid consequences thereof as the animal is
to treat himself.

In all veterinary operations, it is of the first import-
ance, both in regard to the skilful performance of the
operation itself and the safety of the operator, to well
secure the subjects of them ; and in no instance ought
both these considerations to induce us to pay more at-
tention to this preparatory measure than in the present.
It has been said of a surgeon, that " he should have a
lion's heart, an eagle's eye, and a lady's hand ;" but to
the veterinary surgeon, in my opinion, the first of these
qualifications is by far the most requisite ; though his
apprehensions in operating, it is to be observed, proceed
from a different cause from those of the surgeon : the lat-
ter has a fellow-creature's life and a reputation at stake ;
the former, though humanity and reputation, I trust,
always direct his knife, is in momentary bodily fear
from the sudden, violent, and irresistible struggles of
his patient. A finical, apprehensive, timid man is still
more incapacitated for a veterinary surgeon than he is for
a surgeon. Now, I believe it to be a very common
practice with the profession to cast horses to nick them* ;
but if a horse-dealer operate no such precautionary
measures are taken ; and when the number of men
required, the trouble, the time, the apparatus, nay the

* TJie break is now pretty generally out of use : it is a rude, auk-
ward structure, emblematic of the times in which it was framed.

On Nickmg. 113

danger, and above all the convenience of the operator,
be taken into consideration, I feel surprised when I see
it persisted in by any one, and more especially by one
in private practice : from the necessarily aukward and
inconvenient posture in which the horse lies when cast,
it is impossible that the operation can be executed
with that precision with which we can perform it in the
standing posture.

I do not mean to affirm that a horse of a most un-
tractable and vicious disposition may not compel' lis to
resort to such a very objectionable* method of securing
him ; but every practitioner knows how veiy rarely this
is the case ! — my father. Senior Veterinary Surgeon of
the Royal Artillery, who has now been in practice on a
very extensive scale for twenty-eight years, tells me,
that he has never had occasion to cast but one horse to
nick him. The common, the simple, the effectual means
of securing the animal, are the side-lines and the twitch.
First, take care that the twitch be well put on the nose
— so that a considerable portion qf the upper lip be in-
cluded in its twist, but not turned tight until the first
incision be about to be made : then, buckle leathern
hobbles, having rings attached to them, united by a
single rope, around the hind legs, and carry the single
rope over the off shoulder and withers, around the
breast, back again through the ring, and, a second

' I do not consider this epithet too forcible, since many horses
have been killed on the spot by casting. Vide Part I. Lect. xviii.
the only reply to which, on the part of the caster, is, that the oc-
currence is rare and unavoidable ! But is this a satisfactory or con-
solatory account to the owner, when the first groom or horse-dealer
he meets shall tell him " that his horse might have been nicked
standing V

PART n. I

114

On Nicking.

time, around the shoulder and breast ; where it is to be
held firmly by an assistant. In thus securing the hind
legs, let them be brought as far fonvards, under the
belly, as is compatible with the animal's standing.
Sometimes the operation is undertaken out of doors ;
and then, as a firm stay to the hind quarters, the horse
is generally backed against a strong rail, or a leaping
bar ; but the chance of rupture in the hobble rope
(which is not possible if it be of proper manufacture) is
guarfied against in the stable equally well by carrying
another rope, with a noose, around both legs, between the
hock and fetlock, and binding it, in the same manner
as the first, around the shoulder and breast ; or it may
be run through a ring in the manger, and there held by
the assistant. Having thus secured the animal, and the
twitch being sharply twisted *, the operator may fear-
lessly stand directly behind him, in order to include the
hair, at the extremity of the dock, in a ligature of waxed
twine, fast and many times bound around it f. Then,
having raised the tail into the erect position with his
left hand, with a double-edged scalpel, or with a strong
lancet J, held with its point elevated in the right, let
him make, at about three inches from the anus, two

* To some, this precaution may appear liere punctilious and su-
pererogatory. I feel persuaded that no old practitioner will com-
mence the operation before he has ascertained this point ; and I am
desirous to impress the necessity of it on the mind of the young one.

f When the hair is weak and scanty, some tow or suitable ma-
terial should be carried under the dock and intermingled vnth it, and
the whole platted together : this will serve to suspend the tail by,
and probably save, particularly in strong docks, the subsequent era-
dication of hair, from the use of heavy weights.

J: The generality of " nicking knives" are the bawbles or ridicu-
lous inventions of instrument makers. The best instrument for

On Nicki7ig. 115

'ateral incisions through the bare integuments, eoui-
ineacing from the sides of the os coccygis and extending
them to the roots of the hair ; afterwards, let him unite
these cuts by an intermediate incision, which he is to
nake with a light hand, and to be particularly cautious
loes not penetrate beyond the skin : otherwise he will
06 in danger of wounding the inferior ligament and
Df laying open the joint. Next, by repeated strokes
)utwards with the knife, he is to deepen the lateral in-
isions until he has completely divided the fleshy and
endinous bellies of the depressores coccygis. Unless
he subject is a mare *, or that degree of erection only
vhich is known by the " blood tail" is the disideratum,
I second nick is to be made, in a similar manner to the
irst, while the tail is yet elevated, about three inches pos-
erior to it ; having completed which, the operator may
et down the tail, and lay aside the knife. Some make it
practice to divide the muscles a third time, in which
ase the second incision should be made nearer to the
irst : I believe that it is seldom required — certainly not
n a short dock. Seldom much or any blood escapes
k'hile the tail is held upwards — the blood-vessels, in
hat constrained position of it, being compressed, but
s soon as it is relaxed, several small streams issue
rom the wounds. The next step of the operation is to
levate the tail as before and examine the incisions :
he fleshy parts divided will be found to be retracted
nd shortened ; but the tendons, incapable of retraction,
■ ill be seen protruding from the nicks, and more so

n operation is a double-edged scalpel, the lower half of the blade
t which is filed or roughened.

Mares, in my humble opinion, ought never to be nicked ; the
ison is obvious ; and blood horses are but rarely so without dc-
racting from the elegant slope and beauty of their quartern.

I 2

0 -

116 On Nicking.

from the larger than from the smaller ones. These ten-
dinous productions should be excised ; if they are al-
lowed to remain they are disposed to slough and pro-
tract the healing process : for this purpose, give the
tail to an assistant and direct him to hold it perpendicu-
larly/ * ; then seize them with a tenaculum, or pair of
dressing forceps, and snip them off with a pair of probe-
pointed scissars. The tail being kept elevated, now insi-
nuate a pledget of fine tow, with twisted tails, into the
uppermost nick, and, as soon as the dock has been gra-
dually lowered, tie these tails in a fast knot around the
hair: two pledgets are mostly required for the large
wound ; one is sufficient for that below f.

In binding the wounds up with tow, or lint, or other
soft material, after the operation, we have no other ob-
ject in view than the suppression of haemorrhage; when
we imagine therefore that this is fulfilled, without a risk
of relapse, we snip the twisted ends of the bandages
upon the dock in two, and allow them of themselves to
drop off" : the time commonly prescribed for this proceed-
ing is twenty-four hours ; the only objection to half of
that space of time is, that the pledgets would fall oflF
during the night, as the operation is, and very properly,
mostly performed in the morning.

The divided muscles, no longer separated by the in*
tervention of a foreign body, would now unite again,
and with that union recover their lost function, with
but little or no impairment, were the tail permitted to
hang down, relaxed, in its natural dependant posture ;

* In bending it over the back there is danger of rupturing the infe-
rior ligament, and bursting open a joint : this is called " breaking
the tail."

t No dressing whatever should be applied. Digestives and other
farragos are all uncalled for; indeed most of them do harm.

On Nicking. 117

but, the object of the operator being to deprive the de-
pressors of their overpowerful action, measures are now
to be taken to retain them apart until the intervals
become filled by organized adhesive matter. It has
been, and may now be for aught I know, the practice
to allow the tail to remain dependant, without suspen-
sion : the event of this experiment is, that the tail is
carried in the drooping or blood-like fashion ; but, I
believe, that even this carriage is not permanent, in con-
sequence of the muscles, in the course of time, regaining
their wonted tone and power. Now and then, under
such circumstances, unless the parts be kept clean and
free from irritation of any kind, the cuts will degene-
rate into foul and troublesome ulcers ; and these may
require, when freed from dirt and other irritants, some
stimulant or detergent dressing : I should conceive that
it would be generally advisable also to suspend the
tail in these cases, unless it were in a state of active in-
flammation.

Various apparatus have been contrived to answer this
end. It used to be the practice in Ireland, and I be-
lieve is now in some parts, to bend the dock over the
back, and affix it by straps, &c. to the circingle orbelly-
^irth ; and, in this plight, to turn the animal to grass,
without further solicitude about him : this method will
account for the peculiar flexure backwards of the tail in
many of the Irish horses ; in some of which I believe
that the dock has had its ligaments sprained or lacerated,
md its joints in consequence contorted. What are whim-
sically called " nicking machines" have had a few re-
commenders; but not one of these contrivances has
been admitted into general use, nor can I aver that
I have ever seen one that merited it. From the fixture
"f these inventions upon the back, the tail is of neces-

118 On Nicking.

sity drawn at once into a perpendicular, or, what is in-
finitely worse, trained backwards and upwards : both
are overstrained positions, and consist of harsh and
painful treatment during the early stages of this pro-
ceeding; and the latter is further and unanswerably
objectionable from the tendency that it has to produce
that frightful incurvation of the point of the tail over
the back, denominated, in sportsmen's language, the
" squirrel tail." Independantly of all this however, the
difficulty, and even impossibility, of maintaining the
" machine" in its place, are sufficient reasons for decry-
ing it.

In order to keep the dock elevated then, for it is in
that position that the cut extremities of the muscles re-
cede from each other, we have recourse to an apparatus
consisting of lines and pulleys ; which, though from
some little apparent complication and nicety requisite
in its adjustment, I am ready to admit, is not free from
objection, is, on the whole, the most suitable to this end,
and the least painful to the animal, of any that has yet
come under my observation. There are two lines, which
are commonly of lee cord, and two double pulleys
required : the one, the cross line, is extended across tlie
posterior part of the stall, about two feet and a half
above the croup of the horse ; the other, that by which the
tail is suspended, runs through one pulley that plays
from side to side upon the cross line, and another which
is fixed, at some distance from it, directly behind the
stall * : to this line is appended a weight f . The chief
mystery in pulleying consists in making use of a weight

* Some stables are so constructed that this cannot be contrived )
and the tail is consequently pulleyed to one side : now and tlien
it is carried afterwards awry from Uiis.

t This short and imperfect description will suffice to denote the

On Nicking. 119

that will not cany the tail much above the level of the
back for the three or four days posterior to the opera-
tion, and of adding to that weight afterwards according
as the state of the tail may admit, 9r its elevation re-
quire ; for four and twenty hours after, the irritability of
the part is much heightened by the consequent inflam-
mation, during the continuance of which it is that all
the mischief is done by violent suspension : to abate
this, it is an old and a good practice, to keep the dock
wet with cold water.

About the fourth or fifth day, when the swelling and
heat have subsided, the weight may be augmented, so
that the dock be extended at an angle of about 45° from
the body ; and now the horse may be taken out of the
pulleys and walked out daily for about half-an-hour.
Whenever the tail is liberated from the pulleys, which
it should not be at any other time than that of exercise,
the waxed ligature around its extremity ought to be re-
moved, and the hair combed smoothly out and wetted :
this precaution, as well as the sprinkling of the tail
with water while in suspension, will prevent the loss of
hair which is so apt to result from the neglect of it *.
During the second week, the weight of suspension may
be, at twice, still further augmented, so that the taiJ,
about the expiration of that time, be elevated nearly in
a perpendicular line from the croup ; to accomplish
this, however, it will be also necessary to carry the cross

'irt of apparatus here recommended : a knowledge of the method
of applying it can only by obtained by actual inspection.

* When docking and nicking are required in the same individual,
I would recommend that the nicking process be ended before dock-
ing be undertaken; otherwise, a considerable loss of hair may be
'xpericnced.

120 On Nickirig.

line forwards, so that the suspending line run di-
rectly upwards from the tail, when fully erect. This
being the maximum of elevation, it only remains that
we watch the healing process, and every two or three
days have the animal ridden and trotted before us,
in order that we may see what progress has been
made in the carriage of the tail ; for this, as I have so
lately demonstrated, mainly depends upon the force and
application of the means of suspension, and not upon
the mere section of the depressor muscles. If it appear
that these muscles, in the course of a week after the
operation, still retain too much power, we must lose no
time in advancing the cross line, and appending to it
additional weight ; for, unless we exert our mechanical
influence upon them at this period, all subsequent im-
pressions will prove unavailing. In estimating the pro-
per degree of elevation of the tail, our opinion should
be regulated by the general contour of the horse, but
particularly by the conformation of his quarters : the
lank, lengthful, muscular haunches of the racer would
lose that elegant declination and pliancy, in our eye',
for which they are so much admired, were the tail a
cocked one ; no less would the high, prominent, and
well-turned quarter of the charger be degraded by a
drooping tail — what ennobles a hunter with a tail
" set on" rectilineally with a straight back more ifi
appearance than the erection of it ; or what so ri-
diculously and cruelly disfigures the round, fat, squab
rump of a cart horse as a short tail sticking out at
right angles from its centre ! We need not be under
much apprehension, unless a blood tail be desired, that
the erection, so long as no reflex of the dock is obseiT-
able, will be in excess ; indeed, if the high or lofty car-

On Nickitig. I2l

riage of it be the object, we cannot promote its elevation
too much ; for it is a fact well known, that the tail inva-
riably sinks a little in the course of a few weeks after its
final liberation from the pulleys : the organized interpo-
sitions contract, the divided portions of muscle become
less distant from each other, and consequently their
power grows somewhat greater ; and this is the reason
why the tail ought to be kept in suspension for a week,
or two even, after the nicks are quite filled up. Should
the tail at any period be carried awry, which may hap-
pen from some inequality of the lateral sections of the
muscles, or from the suspending line hanging to one
side, it ought to be trained as much as possible to the
opposite side : a little attention to this will not fail ta
right it again.

Before I conclude this subject, I shall make a few re-
marks on the inconsequences that may result from nick-
ing. These are but few, and but rarely met with : so dis-
posed is every injured part to heal and do well in horses,
that daily, nay hourly, is this operation (and indeed all
others almost) performed by unskilful hands, and the
subjects of it treated with perfect unconcern and indif-
ference ; and yet how rarely do we hear of any un-
toward results ! Of whatever nature, they are almost,
always attributable to overweighting the suspending
line early after the operation, and to fixing the cross
line too forward, over the animal's back, or even his
shoulder, and thereby violently restraining the tail ;
so that even here they cannot be ascribed to any indispo-
sition in the parts themselves to take on healthy action.

Tetanus has followed nicking. So far as relates to
the local treatment of the tail, it is advisable, if one be

122 On Nicki7ig.

called in early, to amputate it above the uppermost
incision.

We hear of mortification of the tail after this opera-
tion. Mechanical violence, most unquestionably, may
induce such a state of parts ; but if the tail be removed
from the pulleys, the cause of the mischief, before the
gangrenous stage has commenced, I much doubt its su-
pervention afterwards. The tail (and in some cases the
croup) first grows exceedingly tender to the touch,
swells, and feels hot underneath ; but, if it be taken
out of the pulleys at this time, and proper'antiphlogistic
means actively made use of, the inflammation will sub-
side, and all yet do well. Should the local disease nm
high, abscesses may form in the nicks, burrow among
the muscles, and engender a symptomatic fever in the
system that threatens life itself : I have seen a case of
this description, where everything was judiciously ma-
naged from the very commencement of the operation,
which terminated in death from constitutional irritation.
The primary object here is, to relieve the tail from con-
striction ; the secondary, to counteract the ill efiects
of it upon the constitution : fomentations, simple or ano-
dyne— ^poultices — simple dressings — venesection — pur-
gatives— nauseants, &c. — and a low diet — are the re-
medies we must call to our aid.

LECTURE XXIX.

Muscles of the Fore Extremity.

I SHALL make two general divisions of the muscles
of this extremity, and distribute them, in each division,
into their respective regions.

Muscles of the Shoulder.

None of these muscles pass belov(? the elbow ; the
greater number of them are attached to the scapula and
OS humeri, and are confined in their action to the shoul-
der-joint.

EXTERNAL SCAPULAR REGION

Comprehends three muscles, running upon the
dorsum scapulae, to which they are tightly bound down
by tendinous fasciae.

Antea Spinatus.

Origin. The antea vel supra spinatus fills up the
fossa antea spinata, from which it arises, as well as
from the spine and anterior costa of the scapula.

Insertion. Into the summits of the greater and lesser
tubercles of the os humeri, and into the capsular liga-

124 Postea Spinatus. — Teres Minor.

ment of the shoulder-joint. At the point of the shoulder
it sends off a tendinous expansion over the joint, between
which and the tendon of the biceps we find a bursa
mucosa.

Use. To extend the os humeri on the scapula ; at
least, as far as that motion is admitted of.

Postea Spinatus.

The postea vel infra spinatus is larger than the former
muscle.

Origin. From the fossa postea spinata, and from the
spine of the bone.

Isertion. By a flat tendoia, into the outward part of
the greater tubercle of the os humeri ; by fleshy fibres,
into a ridge extending from it, and into the capsular
ligament. Between its tendon and the tubercle is a
bursa mucosa.

Use. To assist in the flexion of the humerus, and,
seemingly, to roll it a little outwards.

Teres Minor.

A THIN triangular muscle, adhering to the posterior
border of the postea spinatus.

Origin. By an expansion of tendon, from the pos-
terior costa of the scapula.

Insertion. Into a ridge continued from the greater
tubercle of the os humeri, just below the implantation
of the tendon of the former muscle, by a thin flat tendon.

Use. The same as that of the postea spinatus.

INTERNAL SCAPULAR REGION.

The two following muscles lie upon the inward part
of the scapula.

Subscapularis. — Teres Major. 125

Suhscapularis.

A MUSCLE of a triangular figure, filling up the hollow
of the scapula.

Origin. From the anterior and posterior costae, and
from the venter scapulae.

Insertion. By a flat tendon, into the lesser tubercle
of the OS humeri — adhering in its course to the capsular
ligament of the shoulder-joint : between them is a
bursa mucosa.

Use. To assist in the extension of the shoulder-
joint, and to turn the humerus inwards.

Teres Major

Takes its course along the posterior edge of the sub-
scapularis, to which it adheres.

Origin. From the posterior angle of the scapula.

Insertion. By a flat teridon, into the inner and upper
part of the body of the os humeri, along with the
tendon of the latissimus dorsi.

Use. To assist in bending the shoulder-joint, and
to roll the humerus a little inwards.

POSTERIOR HUMERAL REGION.

Behind the humerus is a considerable fleshy mass,
which, although it consists of three distinctly separate
portions, I shall analogically treat of but as one muscle.
It far surpasses in bulk any single muscle of the fore ex-
extremity ; and it bears a close resemblance in disposi-
tion and action to the triceps extensor cubiti of the
human subject.

Triceps Extensor Brachii.

A THICK and powerful muscle, consisting of three
fleshy portions, called its heads.

126 Triceps Extensor Brachii.

Origin. The caput magttum vel ptimum arises, tendi-
nous and fleshy, from the posterior costa of the scapula;
from which its fibres run, in a convergent manner, to
the point of the olecranon.

The caput medium vel secundum takes^ its origin from
the outward sides of the neck and body of the os
humeri, and soon imites itself with the former.

The caput parvum vel tertium, which may be called
the humeralis internum, arises from the inward part of the
OS humeri, near its middle, and runs obliquely down-
wards and backwards, to unite itself with the others,
prior to their insertion.

Insertion. By a strong but short tendon, into the
olecranon of the ulna, which it completely surrounds :
some of its fleshy fibres are continued down upon the
fascia of the arm.

Use. To extend the arm*.

* Every now and then tumors make their appearance at the
point of the elbow. Those I have seen were incysted, loose and
moveable under the skin, solid and firm throughout, of the con-
sistence of cartilage, and not unlike it — being of a callous or warty
nature, in appearance ; they bled readily when cut into, but did
not seem to give any pain to the animal on compression. These
cases require the following operation. Make an incision down to the
tumor, and extend the cut from one lateral limit of it across to the
opposite. Having done this, the tumor may be slipped from its bed
entire ; so that it only remains to cut away the cellular adhesions
around its base. Scarcely any blood will flow but from one, and
that the supplying artery ; which may be tied or cauterised. The
skin should afterwards be brought over the mouth of the opening,
and the case treated as a common wound.

Mr. Feron has met with dropsical swelUngs at the point of the
elbow, which, he says, " frequently take place from bad manage-
ment in the shoeing of the fore feet, by leaving the heels of the
fore shoes too long, by which means the point of the shoes come
in contact with the point of the elbow every time the horse lies

Anconeus. — Coraco Humeralis.

127

Anconeus .

A SMALL muscle, between the back part of the elbow-
oint and the triceps : the latter must be carefully dis-
iected from its point of insertion in order to expose it.

Origin. From the inferior and posterior part of the
)s humeri. It passes down between the condyles of that
bone.

Insertion. Into the olecranon, and capsular ligament
)f the elbow-joint.

Use. To assist the triceps, and to brace the capsular
igament.

ANTERIOR HUMERAL REGION

Comprehends those muscles which are seen in
Vont of the humerus .

Coraco Humeralis.

Origin. By a slender tendon, from the coracoid pro-
cess of the scapula. It becomes fleshy and broad upon
he inward side of the os humeri, in descending upon
he head of which it has a bursa between it and the
tendon of the subscapularis.

I own." — " I have met with some of these watery enlargements in
he elbow of a grey horse of the 12th Light Dragoons, that con-
ained two quarts of water, and after having him tapped, and the
vater evacuated, in three days the swelling was as big as ever." —
• This operation was repeated four times, and nearly the same
luantity was evacuated at each time, making the whole quantity of
'■ ater taken from the elbow-joint, nearly eight quarts, English mea-
Mire." I cannot make up my mind to agree with this writer on the
nature of the swelling : I believe it to have been purely bursal — and
not to have had any communication whatever with the elbow-joint,
•^ce Feron's Treatise on Farriery.

128 Coraco Humeralk. — Flexor Brachii.

Insertion. Into the inner and fore part of the body
of the OS humeri.

Use. To assist in extending the shoulder-joint, and,
perhaps, in turning the humerus inwards.

Flexor Brachii.

This muscle answers, in regard to situation and use,
to the biceps flexor cubiti of the human subject ; it is
not however a biceps muscle in the horse. It is placed
in front of the shoulder-joint ; where its origin is con-
cealed by the insertion of the antea spinatus.

Origin. By a strong round tendon, from the coracoid
process of the scapula. This tendon runs within a
groove between the tubercles of the os humeri ; and the
under part of it, which much resembles cartilage, is
cupped in order to fit it to a bony prominence, co-
vered by cartilage, in the middle of this groove : thus
a pulley-like adaptation, having all the advantages of a
joint, is formed here between the tendon and the bone ;
for their surfaces are lubricated by synovia, and this is
contained within a membranous sac, in order to facili-
tate their motion*. A few, pale, fleshy fibres are seen
running upon the upper surface of the tendon at this
part. Below the head of the os humeri, the tendon
swells into a round, compact, fleshy belly, which,
upon its under part, has still many tendinous inter-
sections.

Insertion. Tendinous, into the inward parts of the

head and neck of the radius ; where it adheres also to

\ i' ' ■ .. •

* The joint-like cavity formed by the tendon of this muscle, has
no connection whatever with that of the shoidder-joint ; so Uiat
any puncture made into the former cannot, with propriety, be called
an open s/touWe»'-joint.

j

Humeralh ExUrm^. —Lameness of the Shoulder. 129

Ehe capsular ligament of the elbow-joint : from it
11 tendinous expansion is sent off to the fascia of
j^e arm.

Use. To bend the arm, by carrying it forwards and
upwards : it is, in fact, an antagonist of the extensor
"orachii.

Humeralis Extemus.

i Origin. From the posterior and inner part of the
leck and body of the os humeri. It turns obliquely
ound that bone.

Insertion. Into the inner and upper part of the body
if the radius, a Httle below the flexor brachii.

Use. To bend the arm.

On Lameness of the Shoulder.

Th e disease vulgarly called founder, body founder,
r chest founder, was supposed by our old writers on
irriery to have its seat in the chest or shoulder ; I
leed scarcely add, however, that the name, as well as
he doctrine, have been justly exploded from our pre-
ent pathology. " Lameness in the shoulder" is the
ihrase now in common use to denote the expression of
)ain, or impediment in action, in the parts composing
he shoulder : a symptom or effect of disease of which

shall now attempt to discover the seat and nature.

Horses so affected have a peculiar halt in going,
rem which alone, in the generality of cases, we are
ailed on to decide that they are lame in the shoulder,
^o such as are familiar with this gait (and every one
nay soon be with a Httle attention) it is almost unne-

essary to say, what may be found in most writers on

PART JI. K

130 On Lameness of the Shoulder.

this subject, that it consists in an inability to project
the affected limb with the usual freedom ; or, as it is
commonly said of the animal, that " he cannot get his
leg forward." When urged to trot — for even these
horses rarely walk lame— ^he evidently experiences pain
every time he advances the lame limb ; for scarcely
has he bent the arm, than he instantly extends it again,
and accompanies the action with a lower inclina-
tion of the head, and a more sudden abaisement of the
sound side than when he is lame in other parts. And
in advancing the lame leg, he makes a sweep with it,
so that if the toe dragged, he would describe a segment
of a circle outwards upon the ground ; and this, with the
occasional " hitting of the toe," and the low and sud-
den declination of the head and opposite fore quarter,
are our surest diagnostics. There is no swelling, no
perceptible heat, seldom any tenderness of the part :
ifhe wasting of the shoulder that is described as a symp-
tom by some, is never present until the disease has ex-
isted for a considerable time ; and when it is, it is solely
referable to the limb being favoured, and the conse-
quent loss of muscular substance, ever attendant upon
a state of inactivity. I am not speaking now of lame-
ness that results from external injury of any descrip-
tion, but exclusively of that which is the offspring of
internal violence.

Having decided that the lameness proceeds from the
shoulder, every reflecting mind will naturally inquire,
where the precise seat is, and what the proximate cause
of the disease present. Some assert, that the mus-
cles, are the parts affected, and more especially the ser-
ratus magnus ; the fibres of which, say they, are eith^

On Lameness of the Shoulder. 131

prained or lacerated. Others, with no less plausibility,
contend that the proximate cause is to be sought for in
the shoulder-joint *. Without venturing to pronounce
both these opinions theoretical — though, I must confess,
from the few opportunities which offer for post mortem ex-
aminations of these parts in a state of disease, I shrewdly
suspect that they are — I do not consider either of
them worthy of implicit reliance in practice ; because I
can name another part, which, in my opinion, is

qually liable to be injured, and will, if diseased, bet-
ter account for the character of the lameness. I allude
to the joint-like connection, I have so lately given a
description of, existing between the tendon of the flexor
arachii and the upper and fore part of the os humeri.
This is a part more likely to be sprained, or have its
cellular and membranous connections lacerated, than
my other, I think ; and it is certainly one that has much
o do in the projection of the arm, which action is here
;o defective : at the same time, I am ready to acknow-
edge, that hitherto my dissections have not cleared up
he point satisfactorily. There is one other fact how-
ever that seems to corroborate this opinion, which is,
:hat, in nine cases out of ten, a blister applied simply
o the point of the shoulder will remove the lameness in
he course of two or three weeks. If it were a sprain
>r laceration of the serratus magnus, a blister so remote
rom it, one would think, would hardly so frequently
five relief ; and if it consisted in a sprain or lacera-
ion of the ligaments of the shoulder-joint, would not

* Gibson calls these accidents "sprains in the shoulder;" but
' has not told us what parts are sprained. In one place, liow-
<T, he says, " sometimes the lameness is in the joint, but ven/
"rely." Gl bson's New Treatise on the Diseases of Horses,

K 2

132v On Lameness of the Shoulder.

it require a longer interval of rest ? I am now speak*
ing generally : what may happen in particular cases, I
cannot provide against. ■
The common causes of this disease are sudden and '
violent muscular efforts of the fore limbs — such as, I
alighting upon them from a high leap, instantaneous ',
springs or bounds in action, treading unexpectedly
with one foot in a rabbit hole, making a false step,
galloping upon heavy or uneven ground, suddenly ;
turning, &c. granting that the tendoii of the biceps is I
the seat of sprain or laceration, it appears to me that
the mischief is done in some sudden and forcible con- |
traction of that muscle.

With regard to the treatment, I have already inti-' j
mated that we are to apply our remedies to the point of i
the shoulder ; and of all others, a blister over its sur-
face is the best. Mild stimulants do not answer so i
well ; rowels and setons are not active enough for these |
cases ; and cold washes and fomentations are next to
useless. A liquid blister should be rubbed in, and re-. |
peated every three or four days, or from that to a week,
according to its effect. Many veterinarians make it a
practice to take blood from the plate vein ; and, if it
be a recent case, the practice is very commendable :
but I would not take more than from four to six pounds.
I think that a dose of physic is in all cases of service.
But, above all other considerations is the quietude of the ;
limb — let it be kept in a state of rest if possible : this is
best attempted by putting a patten shoe upon the foot
of the diseased limb, by keeping the horse racked up,
and by spreading long litter around him.

It occasionally happens, but frequently when the case
has been neglected or miismanaged at first, that, after

li

Muscles of the Arm. — Flexoi' Metacarpi Extemus. 133

this treatment has been persevered in for a reasonable
length of time, the lameness, although considerably
abated, is not entirely removed. This circumstance
appears to be ascribable to the protracted state of inac-
tivity in which the limb has been kept, so that a some-
what contrary mode of practice becomes necessary, in
order to restore the parts to their wonted condition and
tone ; such as turning the horse loose into the stable,
and removing the patten shoe, after a time, from the
lame to the sound leg.

Muscles of the Arm.
The muscles of the arm are firmly bound down by
eudinous fascia, from which the fibres of some of them
re taking their origin : they consist of flexors and ex-
ensors.

SUPERFICIAL POSTERIOR BRACHIAL REGION.

The muscles in this, and the following region, form
he back part of the arm, arise, almost all of them,
rom the internal condyle of the os humeri, and con-
titute the flexors of the leg and foot. They lie imme-
iately under the fascia.

Flexor Metacarpi Externus

Is situated on the outer side of the other superficial
exors.

Origin. Tendinous, from the outer and back part of
le external condyle ; and from the capsular ligament
1 the elbow-joint. Its cylindrical belly, which is in
art made up of tendon, is continued towards the knee,
little above which it sends off a flat tendon that soon
plits into two portions.

134 Flexor Metacarpi Medius ^ Internus.

Insertion. One is fixed to the os trapezium ; the
other passes on through a tendinous sheath to be in-
serted into the head of the outer small metacarpal bone.

Use. To bend the lesr.

Flexor Metacarpi Medius

• Lites along the middle and back part of the arm.

Origin. Tendinous, from the internal condyle of the
OS humeri. Its fleshy belly is somewhat smaller, but
longer, than that of the flexor extenius.

Insertion. Into the os trapezium.

Use. To bend the leg.

Flexor Metacarpi Internus

Takes its course along thein7ier and back part of the
arm.

Origin. Tendinous, from the internal condyle of the
OS humeri — adhering to the capsular ligament of the
elbow-joint. Its belly is smaller and more approaches
the cylindrical form than that of the last-named mus-
cle. Its tendon, which is considerably smaller and
longer, passes through a theca at the back of the knee,
by which it is firmly retained in its place.

Insertion. Into the head of the internal small meta-
carpal bone.

Use. To bend the leg.

Flexor Accessorius Subliinis,

Sometimes called the flexor metacarpi parvus ; but
I prefer this appellation, as the muscle is in truth only
accessory to another of the flexors. Its slender belly
runs between those of the flexores metacarpi, exter-
nus et medius.

Flexor Accessorizis Sublimis Pedis Perforatus. 135

Origin. Fleshy, from the posterior and inward part
of tlie ulna. About midway between the elbow and
knee, it gives off a slender tendon.

Insertion. Into the tendon of the flexor perforans.

Use. To assist the flexor perforans.

DEEP POSTERIOR BRACHIAL REGION.

The following muscles constitute the deep-seated
flexors : they lie anterior to, and are concealed by, the
superficial.

Flexor Pedis Perforatus.

Origin. By short tendinous fibres, in common with
the muscle next to be described, from the lower part of
the internal condyle.

Its fleshy belly is at first blended with the head of the
flexor perforans. At the back of the knee it is confined
by a ligament, which is fixed to the inward part of the
radius ; still lower it is inclosed by a broad transverse
ligament, to which I shall give the name of the liga-
ment um annulare posterins. Along the leg its tendon is
inclosed within a cellular sheath, common to it and to
the tendon of the perforans- At the fetlock -joint it
passes through a large theca, which is lined and cir-
cumscribed by a membranous bag, and contains syno-
via: this much facilitates the motions of the tendon,
and prevents friction between it and that of the flexor
perforans. The tendon at this part is broader, and
much flatter, so as to embrace the one before it ; still
lower, it forms of itself a complete sheath for the ten-
tlo perforans.

Insertion. At the small pastern-joint it splits into
two parts, which are fixed into the upper and back
iiart of the os coronae.

136 Flexor Pedis Perf Oram.

Use. To bend the large and small pastern-joints,
and, in consequence of its liganaentous brace at the
knee, to assist in flexing the leg *.

Flexor Pedis Perforans.

So blended is this with the former muscle, that the
two, were a knowledge of them less important to us,
might be treated of as a biceps muscle.

Origin. The same as that of the flexor perforatusf ;
before which it takes its course. Its belly, which is
somewhat longer thati that of the perforatus, may be
divided into three or four fleshy slips, interlaced with
tendon. At the knee, it passes under the posterior an-
nular ligament, where it partakes of the nature of car-
tilage, and is enclosed, together with the tendo perfo-
ratus, in a complete synovial bag, in which it is con-
fined by cellular connections. Below the knee, these
tendons assume different forms, this being cylindrical,
that of the perforatus flat ; which admits their contigu-
ous surfaces to be broadly applied to each other. In their
passage down the leg, they are both invested in cellular
sheaths, and these sheaths are blended together, and
connected with the feuspensary ligament and oannon
bones. At the fetlock the tendo perforans itself grows
flat ; but lower down it recovers its original shape, and
runs within the sheath formed by the tendo perforatus,
from which it only emerges at the division of the latter.

Insertion. Being opposite to the os coronse destitute of
any tendinous covering, it is enveloped in cellular mem-

* The knee cannot be completely bent unless the elbow is also in
a state of flexion, in order to relax the extensors of the leg and foot.

t The tendinous origins of the flexor perforans, and flexor perfo-
ratus, are connected with the capsular ligament.

Flexor Access. Profundus.-Exten. Meta. Magnus. 137

brane, and is continued over the os naviculars — having
a bursa between them — to be implanted, by an ex-
panded termination, into the posterior concavity of the
OS pedis.

Use. To bend the foot. It will also assist in the
flexion of the pasterns and leg.

Flexor Accessorius Profundus.

B\ some considered as a part of the flexor perforans.

Oiigin. From the middle and back part of the
radius ; where it is concealed by the flexor perforatus.
It gives off" a tendon that joins the tendo perforans ;
which it will assist in action.

ANTERIOR BRACHIAL REGION.

These muscles form the prominent part of the arm
in front, take their origin from the external condyle,
and operate in the extension of the leg and foot. They
have much less power than the flexors, collectively con-
sidered. ' .

Extensor Metacarpi Magnus.

A muscle cylindrical and remarkably compact, found
upon the fore part of the arm.

Origin. Fleshy, from the external condyle of the
OS humeri, and from the body of the bone a little above
it : its fibres also adhere to the capsular ligament.
Below its middle, it becomes tendinous. Its tendon
passes under the anterior annular ligament of the knee,
within a synovial sheath ; where we find a bursa mucosa.

Insertion. In an expanded form, into the anterior
and upper part of the os metacarpi magnum.

Use. To extend the leg.

138 Extensor Pedis. — Extensor Suffraginis,

Extensor Pedis.

Oiigin. From the front of the external condyle of
the OS humeri ; and from the upper and outer part of
the head of the radius. It becomes tendinous near the
same place where the extensor metacarpi does ; than
which however it is smaller. It takes its course under
the annular ligament at the knee, and there plays within
a bursa mucosa, and has a cellular attachment. In
passing over to the front of the cannon it is tied
down by cellular membrane, and in front of the fetlock
and pastern, it adheres to, and strengthens, the capsular
ligaments of those joints.

Insertion. By an expansion of its tendon, into the
lower end of the os sufFraginis, into the os coronae, and
into the coronal process of the os pedis.

Use. To extend the foot and pasterns, and, from
being embraced by the annular ligament at the knee,
to assist in the extension of the cannon.

Extensor Suffraginis *■.

Origin. Amusculak slip, that arises from the upper
and outer part of the radius, and from the ulna. It
ti'ansmits a slender tendon, which passes down by the
side of the ulna, and runs over the inner and fore part
of the knee, within a sheath of its own.

Insertion. With the ligamentum extensorium, be-
tween which and the tendon of the extensor longus it
runs in its course over the cannon, into the upper end
of the OS suffraginis.

* I prefer this name, as being more appropriate, and less likely
to create confusion, to that of extensor metacarpi hngits, having
already magnus and parvus.

Exten. Metacarpi Obliqmts, vel Parvus. 139

Use. To assist in extending the knee and fetlock ;
and probably to keep the ligament tense.

Extenso?' Metacarpi Obliquus, vel Parvus.

Origin. From the outward part of the body of the
radius. Its belly consists of a small fleshy slip, from
which is given off a slender tendon. This crosses under
the tendon of the extensor pedis, but over that of the
extensor metacarpi, to the inward part of the knee;
where it runs through a tendinous theca. '

Insertion. Into the upper part of the os metacarpi ,'
internum.

Use. To keep the tendon of the extensor metacarpi
m its place ; and to assist in straightening the leg.

Before I pass to the hind extremity, I wish to say a
few words about some muscular appendices of the can-
non. By the French writers they are described as so
many muscles : Bourgelat has named them the

Lumhrici,

And from their size and shape, they may be very
well likened to earthworms. So little about them ap-
pears to be known to the profession in this country,
that a surgeon has within the present year published an
account of them with this superscription : — " Two new
muscles discovered."

They consist of two pairs of palish weak muscles,
with long slender tendons.

One pair — we may call the lumbrici posteriores — are
to be found, invested in adipose membrane, adhering
to the sides and inward parts of the tendo perforans,
about one-third of its length upwards from the fetlock.

140

Lumbrici.

Hereabouts they are broad ; but they grow narrow as
they descend, assuming the pyramidal figure, and give
off at the fetlock slender flattened tendons, which seem
to unite and form the crescentic border of a cellular
and tendinous sheath to the tendo perforatus.

The lumbrici anteriores lie within the spaces left be-
tween the small metacarpal bones and the suspeusary
ligament, covered by the flexor tendons. They are
much longer but much thinner than the former, and
come into the class of half penniform muscles. They
adhere for some way down to the ossa metacarpi
parva, become solely tendinous about the middle of the
cannon, wind round the tuberculous ends of the bones
they arise from, and vanish in the adipose substance in
front connected with the extensor tendons.

I cannot assign any determinate use to these small
muscles. They are alike in the fore and hind extre-
mities.

LECTURE XXX.

^s*^ **r* ^■rfv^ ^^'^ '^'^

Muscles of the Hind Extremiti/.

X^HE superficial muscles of the hind extremity are not
bund immediately underneath the skin ; there inter-
venes an aponeurotic covering to them, called the fascia
'at a. Although this fascia invests every part of the
launch, it is not of the same uniform texture through-
out : it is dense, strong, and tendinous in its composi-
lon, upon the fore, outer, and back parts ; but it is
hin, vi^eak, and cellular upon the inside of the limb.
Its chief attachments are to the ileum, the pubes, the
)ssa coccygis , and the stifle : it is continuous superiorly
svith the aponeurosis of the external oblique, and with
the fascia lumborum. Below it extends upon the mus-
cles of the leg — giving them a complete covering — and
vanishes in an expansion over the hock. In many places,
t insinuates itself between the muscles and takes root
n the bone ; in others, the muscles themselves in part
arise from it.

Its use appears to be, to bind down the muscles, pre-
vent displacement of them during action, and thus con-
tribute to their power and effect.

The muscles of this extremity naturally divide them-

142 Muscles of the Haunch. — Tensor Vagina.

selves into those of the haunch, and those of the thigh* ;
I shall therefore draw a line between the regions of the i,;
one, and those of the other. ■

Muscles of the Haunch.

ANTERIOR FEMORAL REGION.

These muscles, four in number, constitute the fore \
part of the haunch : they are all inserted into the stifle.

Tensor Vaginoe.

A THIN flat muscle that lies underneath the fascia j
lata, upon the fore and outer part of the haunch.

Origin. Tendinous and fleshy, from the anterior ■
spinous process of the ileum, and by some fleshy fibres, i
from the fascia lata. About midway between the pelvis,
and stifle it sends oflf a thin expansion of tendon by
which it is inserted.

Insertion. Into the tendons of those muscles that
are fixed to the patella, into the ligaments of that bone,
and into the bone itself. It is also connected to thq i
trochanter minor externus, and continued into the '
fascia lata. : i

Use. To assist in drawing the haunch forwards and
upwards, and, perhaps, in extending the thigh : its, \

primary action, however, is to tighten the fascia lata. ;

i

Rectus

Is a thick cylindrical muscle, prominent upon the an-
terior part of the haunch, covered partly by the tendon
of the tensor vagincE.

* It must be remembered, that what is called the thigh of the
horse, is the part between the stifle and the hock.

' II

Rectus. — Vastus Extemits &> hiternm. 143

Origin. In part concealed by the iliacus, by two
uroad and flat portions of tendon, from the dorsum of
the ileum, a little anteriorly to and above the acetabu-
lum. These tendinous roots, which are rendered indis-
imct by adeps, soon unite and form a round, compact,
rteshy belly, which near its . termination is interlaced
with glistening tendinous fibres. It ends in a short
but exceeding strong tendon, which, before its inser-
tion, is inseparably united with the terminations of the
two following muscles.

Insertion. Into the upper and anterior parts of the
patella.

Vastus Eiternus

Runs along the outward side of the rectus.

Origin. Tendinous and fleshy, from the root of the
rochanter major — investing the inferior part of that
nocess, from the trochanter minor externus, and from
lie whole outward surface of the body of the os femoris.
Its belly is flatter and larger than that of the rectus,
with the tendon of which it is in intimate union.

Insertioti. With the rectus, into the upper and outer
part of the patella.

Vastus IrUernus.

Origin. From the inward part of the neck of the
s femoris, just below the attachment of the capsular
ligament; from the root of the trochanter minor in-
ternus ; and from the whole inward part of the
Ijody of the bone. From these origins, the fibres run
obliquely forwards and downwards, forming a thick
mass of muscle, similar in appearance, though not

144

Sartoriits.

equal in size, to the vastus externus : near its termi-
nation, it unites itself to the rectus.

Imertion. With the rectus, into the upper and inner
parts of the patella.

Use. In consequence of the connection of these
muscles — the rectus and the two vasti — to the tibia,
through the intervention of the patella and its liga-
ments, they become powerful extensors of the thigh ;
and this power is considerably augmented by the
mechanism of the stifle-joint, upon which they are act-
ing with the combined advantages of the pulley and
the lever. They will, in progression, draw the thigh
forwards, and extend it under the trunk ; and, when the
leg and thigh are fixed, they will advance the haunch.

INTERNAL FEMORAL REGION

Comprehends the muscles composing the fleshy
mass upon the inward part of the haunch.

Sartorius

Is a long thin muscle, crossing obliquely over the
inward side of the haunch, immediately under the
fascia lata.

Origin. Fleshy, from the brim of the pelvis, about
midway between the symphysis pubis and the anterior
spinous process of the ileum. In its course, it passes
over part of the psoas magnus and obliquely crosses the
vastus internus ; at the inward part of the stifle it ter-
minates in a thin delicate tendon, which unites itself
to the more expanded one of the gracilis.

Imertion. Into the inner and upper part of the
tibia.

Gracilis. — Vectineus.

145

Use. To assist in bending the leg ; and, when bent,
to rotate the head of the tibia inwards *.

Gracilis f

Is a broad, thin, semi-tendinous muscle, superficially
placed upon the inside of the haunch.

Origin. Tendinous and fleshy, from the symphysis
pubis, as low down as the ischium, where it is united to
its fellow of the opposite side. Its broad, fleshy belly»
striped with tendinous fibres, forms that remarkable pro-
minence upon the inside of the thigh in the living animal.

Insertion. Approaching the stifle, it terminates in a
broad tendon, which is connected with that of the sar-
torius : they are inserted together into the inner and
upper part of the tibia.

Use. To flex the tibia, and rotate it inwards :{: .

Pectinem.

A SHORT cylindrical muscle, that runs upon the
inside of the thigh : its posterior border is connected
with the gracilis.

Origin. From the upper margin of the pubes, near
the symphysis.

Insertion. Tendinous and fleshy, into a ridge of bone
extending from the root of the trochanter intemus.

Use. To flex the haunch, and at the same time
adduct it. '

* The tibia has a degree of rotatory motion when flexed upon the
OS femoris.
t Sometimes called adductor tibialis.

I When the stifle is rotated inwards, the hock is necessarily turned
outwards.

PART II. L

146

Triceps Femoris.

A LARGE fleshy mass occupying the inner and back
part of the thigh, so much of which is concealed by the
gracilis that it becomes necessary to remove that muscle
in order to obtain a full view of it. Its posterior edge is
bounded by the biceps, its anterior by the pectineus and
sartorius. It has, as its name implies, three heads, which
are commonly described as so many separate muscles,
under the names of adductor brevis, adductor longus,
and adductor magnus : I shall first notice the

Caput Breve, which is the uppermost or most
anterior portion.

Origin. From the upper part of the pubes, near to
the sympyhsis.

Insertion. Taking the course of the pectineus, it is in-
serted into the body of the os femoris, behind that muscle.

Caput Longum is situated behind the former, than
which it is much longer.

Origin. From the pubes, in the space between the
foramen magnum and symphysis, behind the origin of
the caput breve. It takes its course along the posterior
border of that head.

Insertion. Into the middle and back part of the
OS femoris — continuing to be attached for some way
down. A slip of this muscle is sent down to be inserted
with the third head.

Caput Magnum is larger and longer than either of
the other heads, and more posteriorly situated.

Origin. As far back as the os coccygis, from the sacro-
sciatic ligaments, and from the tuberosity of the ischium.
Its course lies between the biceps and caput longum.

Gluteus Extentus. — Gluteus Maximm. 147

Insertion. Into the inner and upper part of the tibia,
bcliind the tendinous expansions of the gracilis and
sartorius.

Use. The principal action of all the heads of this mus-
cle is to extend the os femoris upon the pelvis, by draw-
ing it backwards : so that they are opponents to the psoas
inagnus and iliacus. They will also act as adductors —
approach the stifles. The caput magnum will assist the
'exors of the tibia, and rotate it a little inwards *,

GLUTEAL REGION

Includes the three gluteal muscles, and they com-
pose the upper part of the quarter.

Ghiteus Extei-misf.

A fleshy slip placed behind, and united to, the
gluteus maximus.

Origin. From the third spinous process of the
acrum, and from the fascia lumborum. It runs along the
posterior border of the gluteus maximus, between it and
fhe long head of the biceps, over the trochanter major.
Insertion. Into the trochanter minor externus.

Gluteus Maximus.
A muscle of considerable size, lying superficially
upon the outer part of the haunch, and giving that pro-
minence and rotundity to its exterior, so admirable in
a tull-quartered horse. Its fibres are very coarse when
f ompared with those of other muscles ; they are gene-
i"illy also of a darker red hue.

* Those muscles which rotate the tibia inwards, when they have
'lone so, will act as adductors.

t This muscle corresponds, as far as regards its relative situation,
' J the gluteus maximus of the human subject.

l2

148

Gluteus Internns,

Origin. From the spinous and transverse processes
of the two or three last lumbar vertebrae, from those of
the two or three upper sacral, and from the fascia lum-
borum ; from the crista of the ileum, and from its dorsum
and posterior spinous process ; and from the sacro-
sciatic ligaments. From these origins its fasciculi run
in a convergent manner towards the trochanter major.

Insertion. Into the sides of that process by tendi-
nous and fleshy fibres. Between the tendon and the
point of the trochanter is a bursa mucosa.

Gluteus Internus *.

The gluteus maximus must be reflected in order to
expose this muscle ; which is best done by detaching
the former from its point of insertion.

Origin. From the dorsum of the ileum, as high up
as the part where the gluteus maximus ceases to be at-
tached, and as far back as the edge to which the sacro-
sciatic ligament is affixed . It is much smaller than
the afore-described.

Insertion. Into the anterior and less projecting part
of the trochanter major.

Use. The glutei, of which the maximus is by far the
most powerful, are extensors of the os femoris on the
pelvis, or of the pelvis and loins on the os femoris.
When the limb has been carried forwards under the
body by the muscles of the anterior femoral region, and
the toe firmly set down, the glutei will extend the
haunch, and move the trunk onward. Both in rearing
and kicking they are in violent action : in the former,
the limbs are the fixed points ; in the latter, the trunk.

* Vel parvus,

Pijriformis. — Obturator Externus Sf Inlernus. 149

PELVIC REGION.

These muscles, mostly small ones, run from the
pelvis to the upper end of the os femoris.

Pi/rif'o7-mis.

Origin. Within the cavity of the pelvis, from the
transverse processes of the sacrum. It passes out
through the great sacro-sciatic notch, and terminates
in a small round tendon.

Insertion. Into a cavity behind the trochanter major.

Use. To assist in the extension of the haunch.

Obturator Externus"*.

Origin. Without the pelvis, from the rim of the
foramen magnum, and from the external surface of the
obturator ligament. Its fibres run directly outw^ard.

hisertion. With the former muscle.

Use. It vpill assist in the extension of the haunch,
and rotate it a little outw^ards.

Obturator Internus.

Origin. Within the pelvis, from the surrounding rim
of the foramen magnum, over which it expands, and from
the obturator ligament. Its fibres converge, and pass
over the brim of the pelvis, between the tuberosity and
spine of the ischium, and then make their appearance
upon the outside of the pelvis, near the hip-joint.

Insertion. Into the root of the trochanter major.

* The foramen magnum is partly filled by a thin ligamentous ex-
pansion, called the obturator ligament, which is generally enveloped,
in adeps. Muscular fibres are taking their origin from this liga-
ment, both within and without the pelvis.

150 Gemini. — Biceps Femoris.

Use. To draw that process nearer to the pelvis, and
thereby roll the haunch outwards.

Gemini.

Some small fleshy slips, corresponding in situation
to the muscles so called in the human subject.

Origin. From the ischium, between its spine and
tuberosity.

Insertion. Into the root of the trochanter major.
Use. To turn the haunch outwards.

POSTERIOR FEMORAL REGION.

These muscles are found upon the outer and back
part of the haunch.

Biceps Femoris *.

That large fleshy mass, forming the outennost part
of the quarter posteriorly, is made up entirely of this
muscle, which, from its superficial situation, has its
course exceedingly well marked in the quarters of the
thorough-bred horse.

Origin. From the lateral and posterior parts of the
sacrum, and from several of the ossa coccygis ; from
the great sacro-sciatic ligaments ; from the tuberosity
of the ischium ; and from the fascia lata. From these dif-
ferent origins a thick fleshy belly is produced, which fills
up the space between the trochanter major and tubero-
sity of the ischium, and grows flatter as well as smallel'
in its course down the limb : about midway between its
origin and insertion, it divides into two distinct por-
tions, which have separate terminations.

* Biceps cruris of Stubbs.

Semitendinosus.

151

Insertion. Into the outer border of the patella, and
into its external ligament. The second or lower portion
is inserted, through the intervention of an aponeurotic
expansion, into a ridge upon the upper part of the tibia,
and into tlie fascia of the leg, which it adds much to
the strength of.

Use. The heads of the biceps, from haiving different
insertions, will perform different uses. The anterior, or
upper one, will assist the rectus and vasti in extending
the thigh ; but the posterior will aid in its flexion :
they will both have some effect in abducting the limb,
and in rotating it inwards — the hock at the time turning
outwards.

Semitendinosus *

Is placed behind the former muscle, and, with the
semimembranosus, constitutes the posterior boundary of
the haunch.

Origin. From the spinous processes of the two or
three upper bones of the coccyx, and from the fascia
lata. Soon after its origin it becomes inseparably united
10 the semimembranosus, with which it is inserted.

Insertion. By a thin expanded tendon, into a ridge
upon the upper and fore part of the tibia inwardly, di-
rectly opposite to the insertion of the lower head of the
Ijiceps femoris.

Use. It is a flexor of the leg ; it will also turn the
point of the stifle inwards, and consequently the hock
outwards, in which action it becomes an opponent to
the biceps.

* This and the following muscle are sometimes described toge-
tther by the name of abductor tibialis.

152 Semimembranosus. — Muscles of the Thigh.

Semimembranosus .

Origin. With a part of the biceps, from the tube-
rosity of the ischium ; a little below which it becomes
blended with the semitendinosus.

Insertion. By a tendinous expansion, common to it
and the semitendinosus, into the upper and fore part of
the tibia inwardly.

Use. To assist the semitendinosus.

Muscles of the Thigh.

As the fleshy parts of these muscles are all included
between the stifle and hock, they may be considered
under this general head : there is no fleshy fibre below
the hock, and consequently there are no muscles, ana-
tomically speaking, proper to the leg. The first I shall
give a description of, may be said to lie in the

SUPEKFICIAL POSTERIOR CRURAL REGION.

They are all fixed to the os calcis, all extensors of
the hock ; and one of them, at the same time, is a
flexor of the fetlock and pastern.

Gastrocnemius Ext emus *.

A MUSCLE of considerable power that runs superfi-
cially along the posterior part of the thigh.

Origin. By two heads, the outer one from a rough
hollow just above the external condyle of the os femoris,
the inner from the internal condyle, and from a ridge ex-
tending from it. Opposite to the back part of the stifle

* Vel magnus, vel brcvis.

Gastrocnemius Externus Interims.— Plantaris. 153

they unite and form one fleshy belly, gHstening in many
places with tendinous fibres : midway between the
hock and stifle this ends in a flat tendon, easily divisi-
ble into two, which decussates the tendon of the next
muscle.

Insertion. Into the point of the os calcis.
Use. To extend the hock.

Gastrocnemius Internus *.

Situated before the former muscle, which should
be detached from its points of origin to lay this bare.

Origin. From an excavation in the os femoris, a
little above its external condyle, by a round tendon.
Its belly is of less magnitude than that of the gastroc-
nemius externus, but it has more tendon in its composi-
tion. It becomes wholly tendinous about^half way down
the thigh, and its tendon, which is flat, twists round
the flat one of the externus before it reaches the hock ;
so that the relative position of these muscles is reversed
in their tendons In passing over the hock it ex-
pands, and is implanted around the summit of the os
calcis ; thence it is continued down the posterior part
of the leg, and here takes the name of tendo perforatus.
I shall postpone the further description of it until the
tendo perforans come under our notice.

Use. To aid in the extension of the hock, and to
flex the fetlock and pastern.

Plantaris.

The most slender muscle, in proportion to its length,
in the body, creeping in concealment along the outer and
back part of the thigh.

" Vel parvus, vel longus.
+ These parts by butchers arc called the " ham strings."

154 On Capped I locks.

Origin. . In common with the flexor perforans, from
the head of the fibula. Its slender belly gives off a de-
licate round tendon, which unites just above the hock
with the tendon of the gastrocnemius externus, with
which it is inserted.

Use. To feebly assist the gastrocnemii in extending
the hock.

The tendon of the gastrocnemius internus having
crossed that of the externus, expands and forms a theca
for it, which is attached to its sides by cellular mem-
brane. The part that envelopes the tendinous top of
the OS calcis, is hollowed out inwardly, in such a man-
ner that a complete ball-and-socket joint is here con-
stituted, whose cavity is circumscribed, within the space
of about one inch above, and the sa\iie distance below
the point of the hock, by being lined by a thin pellucid
membrane, the surface of which is lubricated by a
synovial fluid, and altogether puts on the appeai'ance
of, and is in fact, a bursa mucosa ; but it is one of un-
usually large size, and one which, from its liability to
disease, is of more consequence to us than most others
of the same description.

On Capped Hocks.
A CAPPED hock (according to some writers, after the
French, a capelet *) may be said to be, an enlarge-
ment of the capsule of the hock. The tumor has a
puffy, elastic feel, and is loose and moveable under the
fingers ; but the animal evinces no tenderness when it
is compressed, nor is there any heat perceptible in it :
at least, these are the ordinary external signs. The

* Seemingly from rape/, the old French word for a covering for
the head— cap, hat, now cliapeau.

On Capped Hoc/cs. ]55

oiumon size and indeed shape of these swellings is that
r the larger cone of a hen's egg ; but they vary much
1 respect of the former*. Writers on this disease
iiard it as a " dropsical sweUing" of the part ; and sc
most unquestionably is in many, but not in all cases,
he tumor contains either a serous or a glareous fluid,
drying in quantity with the size of it, which, when let
Lit by tapping, is generally tinged with blood from the
xternal wound. But I have punctured the capsule, when
has presented all the external character of dropsi-
il accumulation, without, to my surprise, the escape
t' any fluid whatever ; and I have found, on examina-
on, that the enlargement was owing to a thickening of
le tendinous cap itself. Without doubt, in very many
ises the integument will also be swollen ; but this
jeedily subsides, and does not, of itself, properly con-
itute a capped hock. It is but seldom that we see
orses lame from these swellings ; and when they are,
is only temporaiy ; unless there be something extraor-
inary about the case. It may here be asked, why we
ive ourselves so much concern about them, seeing that
ley are not commonly productive of inconvenience ?
\' e do so mostly because they are regarded as blemishes ;
ikI certainly they aje not so without reason : nothing,,
) my eye, more disfigures a horse than a capped hock ;
it mark of degradation, a " broken knee," is not, in
y opinion, more unsightly than this.
This disease may be the product of a sprained hock ;
nt I believe that it will be found to be, with few excep-
' 'US, the result of mechanical injury. In aggravated

Mr. Fkron relates the case of one " that grew as big as. a
"11/ loaf." Treatise on Farrieri/.

156 On Capped Hocks.

cases. It is common to see the points of the hocks excn-
riated or bare, and we find, on inquiry, that these horsi
have been kicking in harness. Sometimes we meet
with horses who are the subjects of it from a vicious
habit of kicking in their stalls, or from lying down
upon pavement without litter : in such cases, before any
remedial means are adopted, it is necessary that mea- i
sures be taken to prevent the recurrence of the cause.

The treatment of these swellings, if they be recent,
is extremely simple. Nothing more is required than an j
evaporating or refrigerent, or what is better than either, [
a discutient lotion *, aided, perhaps, by a dose of t
purgative medicine, or an occasional diuretic. Very
many of these cases indeed need no treatment what-
ever— ^they will subside of themselves ; while others
are thought so lightly of by their owners that we
are not called on to do anything. If the case is j
not a recent one, and there is to the feel a great deal t
of thickening and induration of the capsule, nothing !
is so likely to be of avail in its removal as frequent i
blisters. I would rub about an ounce or an ounce and '
a half of the iiifusum lyttcc upon the swelling once or j
twice a week, according to the effect produced, (taking '
care to wash off the scurfy inspissated discharge every
time the blister was renewed,) and I would turn the :
horse loose into a box, and give him walking exercise !
too, or, if the weather permitted, turn him out altogether.

With regard to puncturing capped hocks, or passing
setons through them, they are both condemnable ope-
rations. Though I have succeeded to the utmost of my

* The formula will be found in Part I. Lecture v. p. 83. Let
about two spoonsful be rubbed in twice a day. Walking exercise is
generally serviceable.

Popliteus. 157

ishes in inveterate cases by these experiments, I have
ad one case in which so much consequent inflamma-
!on first seized the hock, and then the whole limb, that
pte attendant irritative fever, had not active anti-
hlogistics been promptly had refuge to, would to all
Appearances have carried off the patient*. Passing a
eton simply under the skin, so as to establish a cuta-
(eous issue, is too dribbling a counter-irritant to rely
pen.

DEEP POSTERIOR CRURAL REGION.

1 Th e following muscles lie deep-seated, close to the
ibia, between it and the gastrocnemii. They are confined
^own by a tense and strong tendinous fascia.

Popliteus.

Placed at the back part of the stifle-joint, it ap-
•roaches the triangular figure.

' ♦ Mr. Feron details an interesting case, the result of which led
Mm to the same conclusions. A horse of the 13th Dragoons pro-
duced by kicking a considerable dropsical swelling of the point of the
hck, " that grew as big as a sixpenny loaf in less than a month,"
(ind, treated by " powerful astringents and blisters," continued
I grow " larger rather than smaller." Having resolved to treat it like
Ijhydrocele in the human subject, he says, " I therefore took atrocar,
nd let water out to the quantity of three pints, and in the place of
I;. I injected two glasses of port wine, mixed with the same quantity
f water, made blood-warm." — " Very desperate inflammation and
per'' supervened, which, by copious venesection, purgatives, fomen-
ions, and poultices, was subdued ; " and in the course of five
ireeks, from the beginning of the operation, the horse was discharged
fectly cured." Mr. Febon concludes thus — " Although this opc-
ation has been attended with success, yet the inflammation is so
ipid, and the danger so great, that it cannot be recommended as a
ifc remedy, for," &c. Treatise on Fm-riery. Vide " Capelet."

158 Flexor Pedis Accessorius. — Flexor Pedis.

Origin. By a short round tendon, from the outer and
under part of the external condyle of the os femoris.
Its fleshy fibres, which are attached to the capsular 11-:
gament, run obliquely to the inner and back part of the!
head of the tibia.

Insertion. By a broad termination, into the inner
and upper part of the body of the tibia. v

Use. To assist in bending the stifle, and to roll the
head of the tibia inwards.

Flexor Pedis Accessorius*.

Arises just below the popliteus.

Origin. From the outer part of the head of the tibia.
Its cylindrical fleshy belly crosses obliquely over to
the inward part of the leg, where it ends in a small ;
round tendon, which passes through a theca at the
inward part of the hock : near the head of the os meta-
tarsi magnum it runs in the same sheath with the tendon
of the flexor pedis, with which it is inseparably united
about one-eighth of the length of the cannon down-
ward i*.

Use. To assist the flexor pedis in bending the ])as-
tern and cofiin joints.

Flexor Pedis.

Courses the back part of the tibia.
Origin. From the outer part of the head of the tibia,
from the upper half of the body of the bone posteriorly,

* Vel flexor par^'us pedis. ,, .

f Within the theca this tendon is attached hy cellular membrane.
It is not improbable that this is the occasional seat of lameness in
the hock, which would be of the same natm c a sprain of die
flexor tendons.

On Curb.

159

ud from the fibula. At the back part of the hock-
lint it sends off a strong round tendon, which passes
, ithin a groove upon the inward surface of the os calcis,
0 the posterior part of the leg, where it is connected
ith the tendons of the flexor accessorius and gastroc-
emius internus : with the former it unites, and the two
ecome one and the same tendon ; but with the latter
: is only connected by cellular membrane.
I before observed that the tendon given off from the
astrocnemius internus, received the distinctive epithet
f perforatus ; while this, its accompanying tendon, is
ailed the tendo perforans: they are both inclosed in
le same sheath, and are in fact disposed of in a similar
lanner, with regard to the parts below, to what the
;ndons of the same name are in the fore extremity,
hich I must here refer to rather than recapitulate
irther.

Use. The action of the gastrocnemius internus is the
ime as that of the gastrocnemius externus, viz. to
^teud the hock ; but, by means of its tendo perfo-
itus, it will also aid in the flexion of the fetlock and
astern -joints. The flexor perforans will assist the
astrocnemii in extending the hock ; but its principal
peration is on the foot, pastern, and fetlock, of the
ist of which it is the proper flexor.

On Curb.

I HAVE observed that these tendons pass through
parate tendinous vaginae or sheaths at the hock ; it

to the inside of that through which the tendo per-
'l ans passes that we are to look for the seat of curb,
'nv, I apprehend that a curb is nothing more than an
lusion of adhesive matter into this cavity, in conse-

I

On Curb.

quenoe of inflammation, and I \vould say, in common
language, that it was a solid, firm, ill-defined swelling
at the back of the hock, about three inches below its
point *. On its first appearance, heat may generally
be perceived in it, and the animal flinches from pres-
sure ; but, in the course of a few weeks, inflammation
subsiding, the heat leaves it, and it grows hard and in-
sensible to the feel. Generally speaking, to an eye unac-
customed to view these parts in health, a curb is by no
means Hkely to strike the attention ; and, indeed, now
and then, the prominence is so gradual that even
an experienced man may overlook it, unless lameness
direct his attention thither : the common and best
manner of detecting the disease, is to take a side view
of the hock, nicely trace with the eye the perpendicular
of the leg, and accurately note any irregularity of sur-
face ; the feel of it will assist us to form our diagnostic,
and the absence of any such unevenness of surface upon
the opposite leg, will confirm it. If it has made its
appearance on a sudden — and it frequently does so
from galloping upon heavy ground, leaping, &c. it con-
sists, in the first instance, of an extravasation of blood
into the theca of the tendon, in consequence of the
rupture of some small vessels upon its interior, whicli,
when shed, is confined to this spot by the surrounding
cellular connections. But, if no rupture of blood-vessels
has happened, though the part have received that degTce
of violence which must be followed by inflammation, a
curb will not make its appearance until effusion has
taken place into the sheath : this at once explains why

* This is the common site of the tumor ; but I have seen a curb at
the space of six inches from the summit of the hock.

On Curb.

161

orses " throw out curbs" after having stood at rest
•r several hours ; while others shew them immediately
tier work. In curbs of long duration the structure
f these parts undergoes a change, and most of all the
iiing- membrane of the theca : this becomes, in pro-
ess of time, considerably thickened, as well as much
Itered in its texture. '' '"

Any action of the hock in which these parts are
xcrted with more than ordinary force, subjects theiii to
urbs ; and therefore it is that curbs are so frequently seen
II racers after a severe run, and in hunters that have
leen leaped or hard galloped over heavy ground. ' By
lirowing the weight of the rider upon the hocks at a
ime when they are in violent action, cavalry manoeuvres
rid the manage are common excitants of this disease :
he practice of pulling horses up without warning, and'
I' reining them back upon their haunches, cannot, in "a
iiedical point of view, be too warmly censured. Many
iirbs, spavins, thorough-pins, &c. especially in young
lorses, owe their origin to these exercises.

I cannot agree with Mr. Shipp in ascribing curbs to.
)iows : the hock is apart but seldom struck *. Horses
hatare sickle-hocked are more subject to this disease than
t hers ; hence such hocks are often denominated ciirhy —
lot from their having curbs, but from their pre-dis-
losition to have them. '. ■ ' • ;

Recent curbs are generally attended with 'laJtricrri'esS,
^ hich, in some cases, is severe ; a circumstance we are
')t to feel Surprised at when we advert to the nature of

is disease. Nothing, we know, is more painful than in-
il'iinmation, followed by effusion, in a tendinous theca —

'' Siupp's CWs of Farriery.
PAKT II. . M

162

On Curb.

a part that will not admit of extension, in which conse-
quently the nervous filaments, preternaturally sensitive
already, are necessarily subjected to considerable pres-
sure. Some inconvenience in action may be ascribed
possibly to the impeded motions of the tendon. But
in curbs unattended from the first with much inflamma-
tion, and in those cases where the inflammatory action
has subsided, and the parts have accommodated them-
selves to the remaining enlargement and induration,
either no lameness is perceptible, or it is comparatively
trifling.

Our object being to subdue inflammation in the part,
or, what is equivalent to it, remove the lameness, we,
are to resort to such means as are best suited to that
end : we labor however under some inconvenience here
from the peculiar shape and relative position of the
hock. For example, we cannot adapt a bandage, nor
conveniently any covering to the part by which a cold
or warm application — such as a lotion or poultice, can
be kept continually applied. We are therefore com-
pelled to substitute another class of remedies, and for-
tunately for us we have one that is not only as effectual,
but much more manageable. Should the part be very
prominent and convey much heat to the fingers, it would
be advisable, in the first instance, to draw blood to the
amount of four or five pounds from the saphena vein,
exhibit a purge, and keep the hock continually wet with
some repellant lotion *. Seldom, however, is it necessary
to institute this preparatory treatment, from which
no further benefit is to be expected than some abate-
ment of the inflammation ; but we may, in the gene-

* R Sprts ; Vini Ten: ct Aceti p. oeq. Miscequc.

On Curb.

163

ality of cases, without delay, rub a liquid blister upon
he curby surface, and repeat it every week or ten days,
iccording to the effect, taking care not to apply a
econd before the tumefaction excited by the first has
otally subsided. The horse ought to be kept tied up in
he stable during the operation of the blister ; and then
urned loose into a box, and a patten shoe put upon the
>ot of the affected limb, in order to relax the exten-
ors of the hock as much as possible. When the animal
as become sound, it is a good practice to give him the
ua of a paddock for a few weeks, before he be gi adu-
Uy inured to his former work.
Though the above mode of treating curbs rarely fails
) restore the horse to a state of soundness, it is now
lid then necessaiy to fire the parts afterwards, in order
) excite absorption of the remaining thickening and in-
n ration of them ; but not with a view of " making the
irts stand," as vulgar opinion and professional quackery
ill have it*. As in all cases where firing is required,
le lines should be drawn in the course of the hair — here
ngitudinally. The farriers of old, and to my surprise,
le of our best modern veterinaiy writers, have directed

" Cases occur, now and ther;, it is true, that do not appear to be
bin the power of blisters to restore. But it will be found on in-
y, in most if not all of them, that they are of long duration,
>: been mal-treated, or not treated at all, or are relapses, not
onsequence of the omission of the cautery in the first instance,
tiom being put to work before the parts have had time to reco-
r their tone. Some will say, perhaps, that horses that are fired
rst, " stand better." Granted — but what is the reason of it? Not
firing; but tlic longer time that is always given to such horses
re they are considered fit for duty.

iM 2

164

Flexoi- Metatarsi.

" feather firing for curbs ;" why for curbs, above all i
other affections, I cannot possibly divine. Surely,
those of the profession who have earned for themselves
such a reputation for firing that they seem to think
they have a right to unsparingly cauterize that of their .
brethren, will not attempt to persuade us also that their
irons move in unison with their reasoning faculties ;
for if they do, we will retort upon them, and say, thai
their opinions will turn any way so that they " keep
their irons in the fire."

ANTERIOR CKURAL REGION.

These, the flexors of the hock, are muscles of mucli
less power than the extensors. Two of them, in bending
the hock, will extend the foot, actions that are simultii-
neously performed in progression. They are all bound
down to the tibia by a strong tendinous fascia.

Flexor Metatarsi

tiES in contact with the anterior part of the tibia.
Below the hock is a triangular space between the two
extensor tendons, in which we find an attachment of a
few pale muscular fibres that come from the bones of \
the hock : their use appears to be that of preventing
the tendons from rising during action, and of thus con-
tributing to the complete extension of the foot.

Origin. By a tendon of considerable strength, inti-
mately blended with some tendinous fibres belonging to
the extensor pedis, from the lower part of the external,
condyle of the os femoris ; and by fleshy fibres, from the
whole breadth of the upper and fore part of the tibia.
From the last origin is sent off" its fleshy belly \ but from

Extensor Pedis.

165

lie first a theca is derived which partially sheaths the
-•wer portion of the . muscle, and completely invests
rs tendon in front of the hock.

Insertion. This tendinous thecal expansion is inserted
11 to the head of the os metatarsi magnum. The tendon
tself, as it emerges from the theca, splits into two : the
mailer one is implanted into the os metatarsi magnum,
)elow the attachment of the theca ; the larger winds
ound the inward part of the hock, and is fixed to the
lead of the os metatarsi internum.

Use. Simply to bend the hock ; in doing which it
ivill have a tendency to turn its point inwards.

Extensor Pedis*.

The most anterior of the three muscles situated in
I'ront of the tibia.

Origin. From the upper and fore part of the tibia ;
and by a strong cylindrical tendon, (which principally
however belongs to the flexor metatarsi,) from the lower
jiart of the external condyle of the os femoris.

Its belly, which consists chiefly of fleshy fibres, ends
ill a flat tendon, a little above the hock -joint, in froiit
if which it passes in a tendinous theca of it§.pwn/ahd,
upon the anterior surface of the cannon, about one-thirdl
of its length downwards, is so intimately united with the;
lendon of the peroneus that the two appear as but one;
until they have descended to the large pastern-joint, just
above which they disunite and run separate: in their

)i\rseboth are invested in a cellular sheath; In front
I if the fetlock -joint this tendon spreads out, and its fi-
lires continue to expand in,, its passage over the pastern
;md coffin joints.

' Vcl extensor loiigm pedis.

166

Peroneus.

Insertion. Into the coronal process of the os pedis,
and along the upper edge of the bone, between the at-
tachments of the lateral cartilages.

Use. In consequence of this tendon being bound
down by a sheath in front of the hock, it will assist in
bending that joint, at the time that it is perfonning the
uses for which it is particularly designed, viz. the exten-
sion of the fetlock, pastern, and coffin joints.

Just below the bend of the hock, from the upper and
anterior part of the os metatarsi, comes off a thin layer
of fleshy fibres, enveloped in cellular substance, and
concealed in part by the tendon of this muscle, into
which, about one-fourth of the length of the cannon
downw^ards, they are inserted. They may contribute a
little to the extension of the foot, by bracing this ten-
don when the muscle is in action.

Peroneus *.

This is, properly speaking, a peroneal muscle, and
the only one that the horse has.

Origin. From the head of the fibula, continuing to
arise from the whole length of that bone.

Insertion. With the former muscle. It is evident
from the comparative magnitude of the flexor and ex-
tensor muscles and tendons of the foot, that the latter
are greatly inferior in power to the former ; but, \vith
respect to the hock, the reverse is the case, the design
of which is perfectly obvious when we consider what
the actions of these different parts are in progression.
The extensors have nothing more to do than simply
to raise the foot from the ground, and carry it forward
under the trunk ; the flexors have, in the extension of

* Vel extensor brevis pedis.

Peroiieus.

167

he hock, not only to keep the foot firm upon the ground,
s a fulcrum, but to advance the whole machine, and
estore the perpendicular of the hind extremities. This
operation has been well compared to the impulsion of a
Doat by means of oars : supposing the vessel to repre-
sent the body of the animal, and the oars the hind legs,
lie waterman imitates the extensors of the hock while
ugging at his oars, and the flexors in projecting them
nit of the water.

LECTURE XXXI.

On the Ligaments of Particular Joints.

Having, in a former lecture *, endeavoured to con-
vey a knowledge of the mechanism and functions of the
joints collectively, I shall now direct my attention to
them separately.

Articulations of the Trunk.

An d I shall take them into consideration in the order
in which the bones have been described.

Ligaments of the Spine. Those between the
head and the first and second vertebrae, are —

Lateral ligaments, one on each side, a pair that,
run from the coronoid processes of the os occipitis to
the fore part of the body of the atlas, and are fixed at
the roots of its transverse processes.

Ligamentum suspensorium capitis is a broad ligament
inclosed within the capsular. It proceeds from the
body of the atlas, between its anterior articular pro-
cesses, to the upper border of the foramen magnum of
the occiput. It aids in the suspension of the head .

Cavsular ligament is attached to the body of the os

* Part I. Lcct. xyi. js. ^64.

Articulations of' the Trunk. 169

I'cipitis, around tlie roots of its condyloid processes,
hose smooth convexities it includes, and to the body
iid anterior articular processes of the atlas : a process
- sent up from it below to the ligamentous covering of
he odontoid process, which forms a complete partition.

Superior ligament runs from the superior and poste-
lor part of the bony ring of the atlas, to the spine of
he vertebra dentata.

Odontoid ligaments are three in number : — the" two long
ass from the sides of the processus dentatus to the in-
. ard parts of the occipital condyles ; the short, or broad
ue, from the point of that process, along a bony canal,

0 the anterior and inferior part of the atlas.

Inferior ligament, a broad one, connecting (what has
een called) the inferior spinous process of the se-
ond vertebra, to a similar projection of the first.

The capsular ligament between the first and second
ertebrae, is attached to the posterior articular processes
f the atlas, and to the anterior of the vertebra dentata,
> the processus dentatus, and to the odontoid ligaments ;
v hich are interposed between this and the occipital
Jticulation.

In the ordinary movenaents of the head all the cervi- '
cil vertebrae more: or .less participate : it is only in
he nodding motion, or sudden chuck of it, that the first

1 lint is particularly called into action. When the nose is

rried to one side, and elevated, the odontoid process
volves upon its , axis \yithin-the annular opening of the
Uas. -.
The ligaments common to the spine are —
Ligartientum, intervertebrale, in which consists the
lief bond of union between one vertebra and another ;
d so strong is it, that in our efforts to disunite them,

170 Articulatiom of the Trunk.

not infrequently will the bone itself break rather than
this substance quit its insertions. It is constituted of
numerous short and strong ligamentous fibres, arranged
in concentric layers, which run from the anterior or con-
vex part of one bone, and penetrate the concave part of >
that before it.

Ligamentum commune inferius consists of a band of
ligamentous fibres which is passing obliquely along the
inferior parts of the vertebrae, spreading upon their bo-
dies, and coalescing with the ligamentum vertebrale.

Ligamentum commune super ius runs within the spinal
canal, and can only be demonstrated by sawing through
the bony arches : it connects the upper parts of the rings'
together. ■

Capsular ligaments surround the smooth cartilaginous »
faces of the articulatoiy processes.

Intertransverse ligaments fix the transverse processes
of the dorsal vertebrae together.

Interspinous ligaments are found between the spinous
processes of the back and loins .

Ligamentum suhflavum * is an elastic ligamentous
substance, extending from the occiput to the coccyx.
It arises from a scabrous depression in the os occipitis,
behind its tubercle, and there consists of a cylindrical
cord ; but, as it proceeds along the upper part of the
neck, it suddenly spreads in breadth downwards,
and is fixed to all the spines of the cei*vical vertebree,
except the first. It is broadest in front of the withers.
As it approaches the tallest dorsal spine it grows nar-
row again, and, after it has passed the sixth or seventh,
degenerates into a band whose greatest breadth is trans-

* Improperly named ligamentum mtchcc.

Articulatiom of the Trunk. 17 1

ersely. It covers and connects the remaining spinous
processes of the back, and those of the loins, sacrum, and
occyx, upon which it becomes gradually smaller and
mailer, and upon the tip of the last vanishes altogether.
This ligament fomis a strong connecting medium be-
ween the spines of the vertebrae ; and from those of
he neck sustains the weight of the head, which must
)rove a considerable saving of muscular power. Being
ery elastic, it will admit of the extension of these pai'ts,
nd do something towards their contraction.

Ligaments of the Pelvis. The last lumbar
rtebra is united in the same manner to the sacrum to
hat the vertebrae are respectively with one another.
Two superior transverse ligaments are fixed to the
msverse processes of these bones above 5 two inferior,
low, run from the fourth and fifth transverse processes
f the loins to the crista of the ileum.

Sacro-iliac symphysis consists of a cartilago-ligament-
us substance interposed between, and firmly adherent
I, the transverse process of the sacrum and the inward
art of the ileum. This union is strengthened by
Ligamentaiy huiids, which run from the posterior
ine and border of the ileum to the transverse process
the sacrum.

Sacro-sciatic ligaments are broad expansions, stretched
:ross the sacro-sciatic notch. They arise from the
ansverse processes of the sacrum, and those of the
vo or three uppennost bones of the coccyx, and are
xtended to the posterior parts of the ileum and ischium,
nd to the tuberosity of the latter. In the anterior
art of the notch is an oval opening for the passage of
le sciatic vessels and nerves.

172

Dockitig.

Obturator ligament is an expansion, thinner than th^f
last, which is stretched, like a drum-head, across the
foramen magnum ischii.

Ligament of the symphysis is the cartilago-ligamentous -
substance which unites the ossa pubis et ischii, at the inf »
ferior part of the pelvis, to their fellows of the other sidei;

The common vertebral connection exists between th*^
sacrum and coccyx, and between the several pieces o
the latter.

I shall here make some observations on another oper
ation of the tail, called

Docking.

As a man of fashion is known by the cut of his coat,'
so a horse gives evidence of the equestrian spirit of,
his rider in the trim and length and carriage of his taif^

In this country it is customary to dock all but cart
horses *, and generally at an early period of life f ; but'
the breeders, or country horse-dealers, who do this, seK
dom cut more off the tail than to deprive it of most d.

* Many years ago it was, and I believe is now in some pla<
die practice in Norfolk and Suffolk to dock draught horses Uiort-^
on some, not leaving more than three or four inches of tail ; afl
many of these horses, employed to draw road waggons, used
be trimmed half way up the dock, by way of improv'mg th
appearance !

f Some breeders of the present day make it a practice to dock;
thieir foals soon after they are dropped ; with a prospect that " the
hair of the stump will grow strong and thick." I cannot take upon
myself to offer an opinion on this point ; but there is surely one con^.
sideration which ought not, particularly in situations where shade
is scanty or wanting, to be lightly passed over ; and that is, the
use that is made of the tail in switching off flies and other annoyiag-
insects' from the skin, in the summer and autumnal seasoas.

Docking. 173

Is long hair ; so that tlie operation is again required
a lien the animal enters the metropolitan mart. Here
I he dock is shortened according to the prevailing
fashion of the day ; and if this should not happen to
. oincide with the cut of his purchaser, the unfortunate
cieature is subjected anew to torment : so that there is
reason to believe that many horses are even thrice
docked. With regard to the expediency of docking, I
have nothing to do : it would ill become me, as a pro-
fessional man, to decry the operation ; and it is enough
for us to know, that a practice, seemingly introduced
by fashion, has become established by custom, and
that we are often called on to put it in execution.

The performance of this operation is at the present
day held to be so simple, that I will venture to say,
there is no cunning groom, nor horse-dealer, but
what would think it supererogatory, nay even deroga-
'^ry, to peruse a book on this subject; but, however
tacile the amputation of a portion of tail may be (and
certainly the docking knife appears to have reduced its
simplicity to the utmost) a scientific acquaintance with
the operation and its consequences, must always give the
professional man a superiority which no one is better
uble to rate than himself.

In the memory of some, who have been many more
years in the profession than I have, it was the practice to
chop of the tail : the horse was placed with his
quarters against a rail or post, upon which the tail',
being extended, was divided by striking a knife through
the dock with a mallet or hammer. To whom or what
we owe the origin of the present irnproved method of
imputation I know not; but certainly the docking;
knife now in common use is exceedingly well adapted

174 DockiiiS'

to the purpose, and is, probably, altogether as conve-
nient and effectual ail instrument as can be constructed.

When a horse is to be docked, the first, the primary,
the momentous question is, " what is to be the length
of the dock ?" So much does this vaiy with the size,
kind, and general conformation of the horse, and
with the prevailing fashion or caprice of the day, that
I find it ranges from six to fourteen, and even fifteen
inches. With no ambition nor pretensions to "set the
fashion," and with but little to offer in favor of either
side —

" Non nostrum tantas componcre lites — "

I would submit, as my opinion, that nowadays it is
too prevailing a custom to " dock short" our hunters and
roadsters, and more' especially mares: in the two for-
mer, to my fancy, this extreme decurtation of tail de-
tracts greatly from the symmetry of the hind quarters,
and not inconsiderably trespasses upon the majesty of
the tout ensemble of a horse of noble and lofty carriage ;
and as to the latter, there is something really indecent
about the unnatural nudity of those parts ! — but I forget
that our modern sportsmen will not agree with me —
and now I am under apprehensions that some of them
may deem this digression unsportsmanlike ; and there-
fore I will say no more about it.

Having determined on the proposed length of the
dock, the first step towards the operation is to collect
the long hair growing over the place of amputation —
which will be best ascertained by a common rule,
and to plat it, if it is long enough, or bind it if not,
and confine it by ligature to the upper part of the tail.
Next, clip or shear off the short hairs close around the

Docking. 1 75

lock, wliere the knife will be applied, and finally am-
lutate the tail ; the mode of doing which, with the in-
-trument now in use, requires no explanation here : the
•peration so far is simply mechanical, and owes its
•uccess to a little dexterity and strength of arm.
No sooner is this done than the blood spirts oust to
)me distance from the three coccygeal arteries ; and ge-
lerally sundry other hair-like streams issue from their
iurroiinding branches. In this stage of the operation
wo interesting questions present themselves. First, is
t necessary to suppress the hemorrhage ? And, se-
ondly, if it is, what are the preferable means of so
loing ? That many colts are docked, and turned out
ifterwards, without making use of any styptical means
vhatever, with no apprehension on the part of their
iwners, is a fact that would incline us to abandon
liem ; but, independant of the risk that I shall show
N ould be incurred by such a practice at the adult pe-
lod, in horses who had already undergone the opera-
ion, and in whom consequently the blood-vessels had
n creased in size, and most probably in number, the time

I lone required for rest after amputation, in order that the
)leeding vessels might be safely plugged, is a weighty
'bjection to it*. The same arguments hold good

■ In order to ascertain the quantity of blood a horse might lose

II this manner, and whether there were really grounds for alarm
Hider such circumstances, I made the following experiment ; the
i:bject of which was a fine, healthy, young horse, m fat condition,

ndcmncd to slaughter in consequence of an incurable lameness of

■ shoulder. His present dock was ten inches long ; and he had
i"t been nicked. Having trimmed the root of the dock, I ampu-
itf-d eight inches of it, with the common docking knife. Instantly
'"■ '^P'rled out in five distinct streams ; two of which were

176 Docking.

against the temporal employment of ligature around the
dock, or a tourniquet ; in addition to which may be urgecf;'
its occasional inefFectualness in completely arresting*'
the hemorrhage, and the injury which long and violent
compression is apt to be productive of. Some would
wrap the tail in bandages, pledgets of tow, &c. either
dry, or wetted with some astringent lotion ; but the trou-
ble of applying them, the time required for the aiTes'
of the bleeding, and, after all, the uncertainty of th .
event (for I know of no styptic application that can be
depended on) are sufficient reasons for rejecting th
practice. Less objectionable than either of these me-
thods is that of tying the three principal coccygeal ar ^
teries : sometimes they may be readily seized with a'
tenaculum and tied ; but, every now and then, when
the dock has been cleanly severed, these vessels,'.;
or one or two of them, have retracted so far that it

extremely fine, and came from collateral branches ; the three others
issued from the coccygeal arteries, but that from the arteria raedi^^^
surpassed in size and force both of the others — emitting its blood in
(|uick and jetting or pulsating stream. In ten minutes, those froin
the branches degenerated into- droppings ; and the middle arterjj
still emitted more than both the lateral together. In fifteen mi-
nutes more, five quarts and a pint of blood had escaped. During'
the next twenty-five minutes he lost but one gallon ; and in the
subsequent forty-five, only three quarts : making altogether tweV
quarts and one pint. The lateral streams first grew very fine, and
then ceased; tliat in the middle run for a quarter of an hon
after their cessation. The animal, in consequence of the exility
the currents, and the length of time the blood took in flowing
shewed no signs of faintness or uneasiness. Six hours afterwar
though he had been kept tied up, the hemorrhage returned fro
the middle artery, and continued until he was destroyed, whic
took place in tlic course of the succeeding hour.

Docking. 177

IS a very nice and difficult task to lay hold of them
lad draw them forward without rupturing their coats,
ind even an impracticability unless the animal be cast, or
36 very quiet in the stall. The means now, everywhere
! believe in this country, employed to staunch the blood,
s the actual cautery ; and certainly, the simplest of
ipplication, the most effectual, and the safest, it is.
Fhei-e is only one objection that can be urged to its use ;
)me may not regard it as such ; but I consider it to be
iie of great moment, inasmuch as it is grounded upon
hat which a veterinary surgeon ought never to lose sight
)f in the course of his practice — humanity. The animal
vill often literally shriek with agony — and really in the
iresent unskilful and barbarous manner in which that
errific veterinary surgical instrument — a red hot iron,
s made use of, I do not know what can excite more
;xquisite and poignant pain. Let me implore veteri-
lary surgeons then to take this into their most serious
;onsideration ; and not to trifle with the feelings of a
joor brute, who, if he could in language retort upon
liem, would accuse them, and with the greatest justice,
if cruelty grafted upon prejudice. The ordinary method
)f cauterization (one would think we were a profession
if savages) is to hold the dock firmly and fixedly
iexed backwards in the left hand, so that the bleeding
iurface be presented directly upwards *, and then, with
bright red hot iron in the right, which will come in con-
ict with every part but that which is insensible— the
-)one, to sear it with all possible force of application, so
that the skin, (which does not deserve this harsh treat-

* Searing the dock n th s position, it is vulgarly supposed, con-
luces afterwards t. che elevation of the tail !
'"ART 11. N

178 Docking.

ment, for it has not bled,) the cut bellies of the muscles
where they contain no arterial trunks, and the naked
nerves, are all fried together ; but the torture does no'
end here ; in order to prevent a return of the hemorrhage/
the roasted extremity of the dock is now besprinkled wit
pulverized resin, and this is melted upon it by the re-ap*
plication of the hot iron : in this way, the quivering ta*
is converted into a lighted torch, and the sanguinary
scene is concluded ! Nevertheless, the actual cautery^
is the simplest means, the safest, and the most effectual
we possess to staunch the hemorrhage. These advant
ages, which are great to the private practitioner, mightin
duce me to hush up the sufferings of the animal, were i
absolutely necessary that the practice, as here described
should be carried to such a pitch ; but, when it is foun
that the torture may be reduced to pain of much les
severity, and shorter duration, and that the same ad
vantages may be insured, surely humanity has a righ
to cry aloud, and surely we are brutal if we do not lend
our ears to it ! Let the iron, instead of being broa '
enough to cauterize the posterior aorta, and to se"
parts of exquisite sensibility which do not bleed, be o
such dimensions and so shapen, that it may touch the
mouth of the bleeding vessel only ; and let it be at a dull
red heat, instead of being flamingly red hot : will noti
then, the sufferings of the patient be greatly diminished
and abridged ? Yes ! I answer ; and your purpos"'
equally and completely effected. I am not now writing
for those who know no more about the structure of
horse's dock than they do about the construction of
dock for a ship ; but I am desirous to strike the mind
of my professional brethren with the preference that
ought always to be given to a scientific practice — nay,

• Docking. 179

lie policy of it, and the bounden duty of us all to

nstitute as humane a one as is adequate to its ends.

)ne of the most obvious advantages of the cautery,
iver all other styptical means, is, that the horse may

ifely be put to work immediately after an operation
> hich requires but a few minutes for its accomplish-
uent.

It is but very rarely that we hear of any ill conse-
|uences after docking ; and those that have been known

0 occur are, in my opinion, attributable to the unneces-
aiy severity practised in the operation. The sloughing
if the extremity of the stump, which, of course, must
ake place, now and then goes on untowardly ; when it
uust be treated accordingly. Tetanus has resulted from
locking. Here I would, at the onset, amputate the dock
ligher up, with a very sharp instrument, but not sear it
fterwards : should the hemorrhage, which I would at
irst not meddle with, prove alarming, the principal

1 teries may be secured by ligature, or a tourniquet or
i^^ht bandage may be applied . These accidents are more
kely to happen in frosty weather, from that being unfa-
orableto the healing process ; it is as well therefore not

I operate during frost, unless the animal be kept the
\ hfle warmly housed.

Ligaments of the Ribs. Every rib is connected
o two vertebrae by four ligaments.

Capsular ligament of the head invests and holds it
.ithin its vertebral socket. Two articular cavities are
ormed within it, one with each vertebra, which have
tiparate synovial linings. This union is strengthened
ly some ligamentous fibres that proceed from the summit
'f the head.

N 2

180 Articulations of the Fore Extremity. !

Capsular ligament of the tubercle surrounds it at its J
articulation with the transverse process of the vertebra. «

External and- internal ligaments consist of strong h
fibres vrhich connect the neck of the rib, above and
below, to the spine.

Intercostal ligaments are broad fibrous bands which run
obliquely across the intercostal spaces, and hold the
ribs and their cartilages firmly together.

Sternal ligaments. The several pieces of the sternum
are united to each other by intervening cartilago-liga-
mentous substances ; in addition to which they are con-
nected by ligamentary bands, both inwardly and out-
wardly. The fore part of it is surmounted by a broad
portion of cartilage, which runs along its under part, *
somewhat like the keel of a ship : this is the cariniform
cartilage.

Articulations of the Fore Extremity.

SiiouLDEE-joiNT is composed of two bones : — the
scapula and the os humeri. Their adaptation to each
other is incomplete, in consequence of the comparative
magnitude of the ball of the one and the socket of the
other ; though the superficies of the cavity is somewhat
extended by a narrow border of cartilage.

The capsular being the only ligament connecting
these bones, we find that it is strengthened in many
places by additional fibres dispersed upon its exterior.
It is very loose — bagging about the bones, that it may
not restrain their motions. It is fixed to the rough
margin of the glenoid cavity, and to the neck of the
OS humeri. A synovial membrane lines it, which may
be followed upon the cartilaginous surfaces of the bones
Externally this ligamentous capsule is clothed on every

Articulations of the Fore Extremity. 181

side by muscle :— the an tea et postea spinati invest
its outer and anterior parts, the subscapularis and teres
minor, its inner and posterior : to them is attributable
the main strength of the joint.

The OS humeri may be freely flexed backward upon
the scapula, but cannot be extended forward beyond
that line in which we see it placed in the skeleton. It
may be abducted or adducted a little, and, but very
limitedly , rotated * .

Elbow-joint -f- consists of the os humeri, the
radius, and its epiphysis, the ulna. The ligaments of it
are two lateral, and a capsular.

Internal lateral ligament is implanted above into a
depression upon the side of the internal condyle of the
OS humeri, and below, by two portions, into the margin
of the inner articular concavity of the radius, and into
its body, about three inches lower.

External lateral ligament, shorter and stronger, runs
from a similar depression upon the external condyle to
a tubercle upon the upper part of the radius.

Capsular ligament, which is thin, is affixed to the
condyles of the os humeri, including the smooth parts
of those projections and the hollow behind them,
to the edge encircling the top of the radius, to the
lateral ligaments, and to the ulna around its articula-
tion : it is also attached to that tendinous substance by
which the flexors of the leg have their origin. The

A horse evinces these powers in the passage de fnancge — in turn-
ing round by his hind legs, making pivots of his fore— in turning
iiis toes in or out in going, &c.

t So denominated, from the projection of the olecranon, in the
phraseology of the riding school.

182 Articulations of the Fore Extremity.

lateral ligaments, as well as the capsular, and other
parts, receive a synovial lining.

The motions of this joint are confined to flexion and
extension.

In the young subject the ulna is joined to the radius
by a strong, fibrous, elastic substance, of a cartilago-
ligamentous composition, which yields to the instanta-
neous recoil of that bone, in extraordinary efforts, during
action. From its tubercular end a ligamentous band
runs to the knee. Ossific matter unites these bones in
the adult ; and the ulna becomes a fixture.

So long as it is moveable, this joint co-operates with
other elastic parts in preventing concussion.

Knee-joint. In the knee there are five distinct arti-
culations : — one between the radius and the three small'
bones of the upper row ; a second between the small
bones, above and below ; a third between those of the
lower row and the metacarpal bones ; a fourth between
the OS trapezium and the os cuneifomie ; and a fifth
between the os pisiforme and the os trapezoides. They
have all separate capsular ligaments, and synovial linings.

The ligaments of the knee, and the tendons passing ,
over it, are girt by broad, glistening, ligamentous bands,
which retain the latter in their places, and render the
joint stronger and more compact. Between these liga-
mentous fachiae in front and the extensor tendons, are
some large bursae, that facilitate the play of the latter.

External lateral ligament is that which runs from a
tubercle upon the radius to the head of the external
metacarpal bone.

Internal lateral ligament consists of two parts, which
proceed from a similar tubercle upon the inside, and

Articulatiom of the Fore Extremity. 183

i om the body of the radius : — the longer is fixed to the
lead of the internal metacarpal bone, the shorter and
•loader to the inner and fore part of the large meta-
carpal bone.

Ligamentum annulare passes from the os trapezium to
lie ossa scaphoides et cuneiformia : it confines the
iexor tendons.

The motions of the knee, which reside chiefly ia the
wo upper large joints, are complete flexion backward,
iiid extension. To have given this part lateral motion,
vould have endangered the security of its joints.

I have heard it said, that the knee of a horse was
iixated in galloping down a steep hill in the chace ;
lit as there is no professional attestation of such ati
iccident, I must withhold my belief of the fact : it is
•xtremely improbable that any one of the bones of the
aain joints was actually driven from its place.

Cases present themselves now and then in which the
)ursBe in front of the knee are dropsical and enlarged :
hey seldom or never give rise to lameness.

Fetlock-joint. This joint is composed of the
's metacarpi magnum, the os suffraginis, and the ossa
samoidea.

Capsular ligament is attached around the articulatory
urfaces of these bones ; and the synovial membrane,
.fter having lined it, is reflected upon their cartilages :
t is guarded in front by the extensor tendon.

Long lateral ligament is fixed to a little projection
I pen the side of the os metacarpi magnum, and to the

suffraginis.

Short lateral ligament, running underneath the for-
iicr, arises from a depression in the os metacarpi mag-

184 Articulations of the Fore Extremity.

num, and is inserted into the bone below, immediately
behind the long one. Being short and tense, when the
joint is extended, these ligaments will guard strictly
against any motion sideways ; which would necessarily
give a tendency to dislocation.

The ligaments of the sesamoid bones are seven : — the i
superior or suspensory, the long inferior, the short in- .
ferior, the two lateral, and the two crucial. <
Suspensory ligament, so called, I imagine, because the
ossa sesamoidea ai-e suspended by it, is one of the
strongest ligaments of the body, and differs firom most
others in having the property of elasticity. It com-
mences from a projection upon the upper and back part
of the OS metacarpi magnum, passes down, in a cellular
sheath, between the ossa metacarpi parva, (filling up
the space betweeii them,) and opposite to their tuber-
cles splits into two portions, which are implanted into
the outer and posterior parts of the sesamoid bones, and
into the cartilaginous substance uniting them. From it
two lateral slips of ligament are continued down to the
extensor tendon. Enveloped in adipose membrane, be-
tween it and the lower part of the os metacai-pi mag-
num, are several bursse mucosae.

This ligament exhibits a remarkable aspect when cut
into, from having a peculiarity in its composition which
would almost incline one to doubt how correctly it is
regarded as such. Bourgelat has treated of it as a
tendon*; Girard, as a muscle f. It is deeper in
color than either ligament or tendon in general ; it is
fibrous, but its fibres are very coarse, and are disposed
in layers ; but its essential diflference consists in an ia*

* Lc tendon suspcnseiir du boulet.

f M. tarso-phalangicn.

Articulations of the Fore Extremity. 185

rtexture of fine, red, muscular fibres, which appear to
e the uniting medium of the others. This intermixture
f muscle, in the composition of the ligament, in itself
lastic, must greatly contribute to its power of contrac-
Lon, after having been forcibly extended by the de-
n ession of the sesamoids ; and nothing can more vividly
lucidate my remark, in speaking of those bones, than
his singular and unique structure. " The suspensory
j:ament by its re-action, instantaneously after exten-
lon, we feel inclined to believe, aids the flexor muscles
■ I bending the pastern-joints: the astonishing activity
ud expedition displayed in the movements of the race-
lorse, at speed, seem to be referable, in part, to the
)romptitude with which the suspensory ligament can
ct before the flexor muscles are duly prepared ; the
alter, we should say, catch, as it were, and then direct
he limb, first snatched from the ground by the powers
if elasticity *."

If the tendons of the flexor muscles of the pasterns
I nd foot are cut through, these joints become relaxed and
he animal walks, and with tolerable freedom, upon the
notuberant heels of the horny frog and posterior parts
)f the wall ; but if the suspensory ligaments too are di-
/ided, the joints then being entirely deprived of their sup-
jort behind, the toe of the hoof turns up, the pasterns
ire forced down horizontally upon the ground, and the
inimal actually walks upon his fetlocks, without much
ihance of falling so long as he is not hurried out of this
pace. This proves to us, that the suspensory ligaments
vre the real braces, not only of the fetlock, but of the
pasterns, and that, in consequence of the sesamoids

* Part I. page 334.

186 Articulatiom of the Fore Extremity.

being deprived of their means of suspension, these
joints sink down, and are protruded, or, in the jockey's
phrase, are " let down." Concerning their operation,
during action, I have already made some observations
in my lecture on the skeleton *.

Long inferior ligament runs from the bases of the
ossa sesamoidea, along the back part of the os sufFra-
ginis, to the upper extremity of the os coronae. This
ligament will assist in retaining the sesamoid bones in
their places, and materially strengthen the pastern-joint
behind ; but, in my opinion, this does not comprise one
chief design of it. In consequence of its being spread
over the pastern-joint, and the obliquity of that part in
the skeleton, I imagine that, in action, it is forcibly im-
pressed by the lower end of the os sufFraginis ; to which
impression it would be incapable of yielding, were it
not attached above to the sesamoid bones, and did it
not, through them, exert an extensional action on the
suspensory ligament : so that the operation of this much
admired structure, to ward off concussion, is not con-
fined to the fetlock, but, by means of the long in-
ferior ligament, is in part transmitted to the pasterns.

Short inferior ligament arises, by two portions, from
the bases of the ossa sesamoideum, partly concealed
by the long ligament, and furnished with bursse as
it passes over the projecting parts of the os suffra-
ginis. It is implanted, a little lower down, into an an-
gular asperity well marked upon the os sufFraginis. It
binds the sesamoid bones to the large pastern, and
strengthens the fetlock.

Lateral ligaments are extended from the outer, pro-

* Vide Lecture xx. Part I.

Artkutatiom of the t'ore J^xtremiiy, 187

cting angles of the ossa sesamoidea, in part to the os
uetacarpi magnum, and in part to the os sufFraginis :
binding these parts closely and strongly together.

Crucial ligaments are a pair brought into view by
iissecting off the inferior. They run, decussating
ach other, from the bases of the ossa sesamoidea to
he upper and posterior or projecting parts of the os
iifFraginis. In metaphorical illustration of the use of
hese ligaments, I would call them the hinges of the
esamoid bones — the connexion upon which they turn
a performing that retro-cession I have heretofore as-
ribed to them.

No part is oftener the seat of lameness than the fet-
;ck and its appurtenances ; for there is no articular
art more complicated in its construction. In horses
■rought to us for " sprains of the back sinews," we
00 commonly regard the flexor tendons as the only seat
f injury ; without reflecting that such is the deep-
eatedness and concealment of the subjacent parts
liat their diseases can seldom be detected but by nice
nd accurate taction, and even then, but too often, in

very imperfect manner. In a great proportion of these
ases, where much violence has been the fore-runner,

imagine that the suspensory ligament must be
prained ; and in the worst cases, probably some of its
hres even ruptured : but owing to the quantity of the
■Uular membrane investing it, its depth of situation,
nd the occasional subcutaneous extravasation conse-
[uentupon the injury, the case will put on all the appear-
nces of a common sprain, and, fortunately for the prac-
itioner, require then the same course of treatment*.

* Vide Lecture xii. Part I.

188 Ariiculatiofis of the Fore Exlreiuily.

The joint itself, from its being the chief seat of
motion below the knee, is very subject to inflammation; "
generated in it either by long endured exertion, or by
occasional acts of violence. I have seen a few cases
in which this has speedily terminated in an accumula-
tion of synovia — hydrops articuli — giving rise to a little
pufiiness in the joint itself, and to a snapping noise on '
motion of it, as if the cannon bone left its socket every
time the limb was elevated, and slipped in aga;in on its
being grounded. This dropsical condition of the joint
is often accompanied by a similar one of the large
bursee interposed between it and the suspensory liga-
jtnent ; and in the course of time, more especially if the
animal continue to work, a communication is likely to
be established, by absorption, between them. For th^
treatment of these cases, and, the further consideratioil
of the subject, I must refer to the lectures on the dis-
eases of joints, and bursae mucosae.

Pastern-joint is formed by the adaptation of the
ossa suffraginis et coronae. It has a capsular, and tw.
pairs of lateral ligaments.

Capsular ligament infolds the smooth cartilaginous
ends of these bones, and is firmly inherent in their
borders : it is intimately blended with the extensos-
tendon in front, and behind is inseparably united with
the long inferior ligaments of the sesamoids.

Long lateral ligaments are rooted in rough surfaces
upon the sides of the os suffraginis ; whence they pro-
ceed to the OS coronas.

Short lateral ligaments, broader and stronger than th?
former, are attached, anteriorly to them, to the bones
above and below.

Articulations of the Fore Extremity. 189

The long- inferior ligament of the sesamoids protects
\is joint behind, and the extensor tendon forms a broad
efence to it in front ; indeed both these bands are so
nitted in texture with the capsular ligament that they
lay be said to constitute the greatest part of it.
The motion of this joint is veiy inconsiderable. It
every where evident in the construction of this and
le joint I have but now described, that the chief de-
s^n has been, to confine their movements to those
f simple flexion and extension ; otherwise, unprotected
s they are by muscle, they must have been insecure,
nd unfit for the purposes of supporting, moving under,
ad propelling, a burden of several hundred weight.
)islocation in them is an unheard-of accident ; but, as
light be expected, their ligamentous connexions are of-
m the seat of inflammation, which, unless it be early
let by efficient remedies, never quits them until it has
lid the fotmdation for that irremediable evil, ringbone

Coffin-joint is made ijp of three bones : — the

sa coronae, pedis, et naviculare.

Capsular ligament inwraps their articulatory surfaces,
id fixes itself beyond their limits : in front it is insepar-
bly united with the expanded extensor tendon, be-
ind it is much strengthened by the tendo perforans.
n addition to the capsular, there are three pairs of
;aments.

First pair passes from the superior edges of the alse
f the 03 pedis, to the lateral parts of the os coronae,
nd are inserted about its middle.

I allude to that ringbone which, from its situation, interferes
'h the motion of one or other of these joints. Vide Lecture xx.
•rt I.

190 Artimlatiom of the Fore Extremity.

Second pair is stretched from the extremities of the
alae to the os coronae, and are fixed below and behind
the first.

Third pair arise from the sides of the coronal process,
and terminate in the cartilages.

The ligaments of the os naviculare are four : — two
single, and one pair.

Superior ligament runs from its upper and posterior
part to the tendo perforans.

Liferior is a very broad ligament ; arising from the
whole of the lower edge of the bone, and thence extend-
ing across to the body of the os pedis, above the long
extensor tendon.

Lateral ligameiits fix the os naviculare, by its two ends,
to the sides of the os coronse.

The coffin-joint is not furnished with lateral ligaments
of equal strength to those found in the pastern and fet-
lock, and for this reason — because it lies buried within
the hoof, where it is well protected from external injury,
and where it is impossible to be luxated. It has no
other motions than flexion and extension, and them but
limitedly ; less so, however, than the pastern-joint. I
forbear here to offer more on the functions of these
parts, as they must necessarily come again under notice
in speaking of the foot ; and probably it will be judici-
ous to reserve until then what I have to say about their
diseases *.

✓

* In Part I. page 341, I have said, that I never saw or heard of
a case of fractured navicular bone. Since the publication of the First
Part, I have been favoured with the inspection of two specimens of
this accident, which are now in the possession of Mr. Field. The
fractures, in both, it appeared to me, had their origin in caries of the
bone.

Nothing can afford me more satisfaction than the retraction or

191

Articulations of the Hind Extremity.

Thigh-joint is formed by the reception of the ball
or head of the os femoris into its socket, the acetabulum
of the pelvis.

Capsular ligament, which is very thin, and incapable
of great resistance, is attached around the cervix of the
OS femoris, and the margin of the acetabulum ; it is
thickly clothed on every side by muscle, which is a
defence and an effectual security to the joint.

The acetabulum is surrounded and deepened by the
circular ligament ; whose border turns inward to em-
brace the cartilaginous head of the os femoris.

The notch in this cavity, to its inward side, is crossed
by the transverse ligament, which here makes up for the
deficiency in the bone .

Ligamentum teres consists of a bundle of ligamentous
fibres, inclosed in a sheath, which proceed from a pit in
the inner and upper part of the ball to a similar one in
the roof of the socket : another portion of it leaves the
cavity under the transverse ligament, and is implanted
into the pubes. This ligament holds the bone, when
its capsule is ruptured. The synovial membrane, after
having lined the socket, is reflected over these parts.

Stifle-joint is composed of the os femoris, the,
tibia, and the patella. Its ligaments are many, and par-
ticularly worthy of notice, from its being the occasional
seat of lameness, (which is often deemed or proves in-
curable in consequence of the nature of it not being

correction of such-like statements, so soon as I may haMS been
warned of my error. None of us are at all times faultless ; and
those who write on many and various subjects, are generally most
subject to error, and ought to be most pardonably so.

192 Articulations of the Hind Extremity.

understood,) and from the liability of the patella to dis-
placement.

Those exterior to the capsular ligament are the ligu-
menta patella-^fom strong cords, which descend from
the lower part of that bone, over the condyles of the os
femoris, to be fixed to the tubercle of the tibia. The ex-
ternal one passes upon the outer and anterior part of the
external condyle ; the inter nal upon the inward part of
the internal condyle ; and the middle one, between them :
they approach one another in their descent. Concealed
by the external one is the fourth ligament of the patella :
it runs to the outward part of the tibia.

The patella, with the pulley-like articulatoiy surface
of the condyles in front, forms a joint of its own, per-
fectly distinct from that between the tibia and os fe-
moris.

Its capsular ligament is fixed to its surrounding border,
and includes the smooth parts of the condyles which the
bone slides upwards and downwards upon : to admit of
this motion, the capsule is veiy loose, and a quantity of
adipose matter fills the interspaces of the ligamenta
patellae.

Internal lateral ligament descends from the internal
condyle to the inner and upper part of the tibia.

External lateral ligament, stronger than the internal,
runs from the external condyle to the upper end of the
fibula.

Capsular ligament of this joint is loose and thin. It
is inserted around the condyles of the os femoris and
the uppei-most part of the tibia : it is also attached to
the lateral ligaments, and to the semilunar cartilages.

Within the capsular ligament, partially dividing the
cavity, we find the semilunar cartilages. They are of a
crescentic shape, seated upon the articulatory surfaces

Articulatiom of the Hind Extremity. 193

of the tibia, thick around their borders where they are
attached, thin inwardly and loose within the joint. The

!se of them appears to be, to form sliding sockets for

lie condyles.

The ligaments of the cartilages are — the two anterior,
which are implanted into a pit upon the fore j3art of the
tibia; and the three posterior, of which one attaches the
inner cartilage to a rough depression upon the tibia, the
two others bind the outer cartilage to the hollow be-
hind the condyles, and to the back of the tibia.

These cartilages admit of additional freedom of mo-
tion, and diminish the risk of dislocation.

Crucial ligaments, short and strong, and deeply buried
within the joint, run from the space between the con-
dyles to scabrous pits upon the tibia.

The synovial membrane, after having lined the cap-
sule, is reflected upon the cartilages and ligaments in-
cluded within it.

HocK-joiNT, like the knee, is everywhere invested
by a cellular covering, interlaced with ligamentous
bands, which sheathe and confine the tendons as they
pass over it in a manner already described.

It has four lateral ligaments : — two on each side. Of
the two internal — the long one runs frctm an eminence
upon the lower part of the tibia to the astragalus, thence
it spreads upon the ossa cuneiformia, and is ulti-
mately fixed to the internal small, and also to the large
metatarsal bones ; the short one proceeds from the same
eminence upon the tibia, crossing under the long one,
to the OS calcis.

Of the external lateral ligaments — the long one runs
from the opposite part of the tibia to the os calcis, ex-

I'AKT n. o

194 Articulations of the Hind Extremity.

pands upon the ossa cuneiformia, and terminates upon
the internal small, and large metatarsal bones ; the
short one, taking a cruciform course under the former,
is fixed to the tibia above, and astragalus below.

Capsular ligament, everywhere thick and strong, in-
cludes the lower end of the tibia, and the pulley-like
part of the astragalus ; to both of which bones, to the
lateral ligaments, and to the os calcis, it is firmly at-
tached.

The astragalus is retained in its place by lateral liga-
ments which are fixed to its sides, and thence pass to
the metatarsal bones. It is closely attached by sepa-
rate capsules to the os calcis, and cuneiforme magnum,
with which it forms distinct articulations.

The OS calci^ forms a joint vnth the os cuboides, upon
which it rests. It is bound in its situation by short
ligaments with the astragalus, tibia, and metacarpal
bones.

The ossa cuneiformia are themselves in joint-like ap-
position ; and the middle and small bones make joints
with the OS cuboides above, and the ossa metatarsi
below.

So that there are no less than six articulations in ad-
dition to what we commonly understand by the hock-
joint — that between the tibia and astragalus. And with
great reason do we so designate it ; for by it are the mo-
tions of this part, which are restricted to flexion and ex-
tension, almost wholly performed. This joint probably
has more exertion to endure than any one in the body ;
at the same time it has to admit of free and extensive
motion : had this motion been variable, as well as exten-
sive, a more complicated structure would have been re-
quired ; not only from the nature of the articulation of

Articulations of. the Hind Extremitij. 195

the bones is lateral motion prohibited, but it is carefully
guarded against by a double number of lateral liga-
ments, and by their decussation. This joint is well de-
fended, and further strengthened, by the tendons
that run over it. It is the seat of several diseases
which I have already made the subject of inquiry : an
additiorial ai-gument,^ vti my mind, to show its utility
in progression.

o 2

LECTURE XXXII.

On the Common Integuments.

Under this head the ancient anatomists included
the cellular membrane and the panniculus camosus,
which they called the muscular membrane ; but, by the
modem acceptation of the word, integuments, nothing
more is meant than what, in common language, is called
skin: the epithet common, which is mostly prefixed,
only serving to denote their uniformity over every part
of the body. In human anatomy the hair and nails are
generally described as appendages to the skin, and, to
carry on the analogy, I might thus consider the hair
and hoofs, whose nature is equally cuticular ; but the
hoofs, when compared with the nails, are parts of so
much more importance, and are parts which, of late years,
have excited so much interest in veterinary anatomy,
that, I think, it would be injudicious to Unk them in
description to any organ as an appendage.

The common integuments consist of three parts,
which differ in appearance, texture, and organization
from one another : — the cutis, cuticle, and rete muco-
sum.

197

The Cutis.

The cutis vel dermis, sometimes designated the cutis
vera or true skin, is the most substantial constituent of
the common integuments, being that which the tanner
converts into leather : it lies underneath, and may be
said to be (in the full sense of the word) the support of
the other two.

The cutis is attached to the subjacent parts by reti-
cular membrane, in some places so tensely that little or
no motion is admitted of, in others so loosely that it
may even be thrown into folds : — about the forehead,
upon the back and quarters, around the dock, and upon
the pasterns, it is so tight that we can but with great
difficulty include a portion between the finger and
thumb ; but, upon the side of the face and neck, upon
the ribs, under the belly, and upon the arms and thighs,
it will easily admit of corrugation ; indeed, between the
fore legs are several semicircular doublings of it, in
order that the action of the fore extremity may not be
constrained ; and along the posterior part of the belly,
and about the flank, are other folds, not so numerous,
but of larger size, that give freedom of motion to the
hind parts : in fact, wherever the panniculus runs it
is loose, or that muscle could not have imparted to it
the power of corrugation.

There is considerable variation in the thickness of the
skin, not only where it covers different parts in the
same individual, but in horses of various breeds. What
a contrast there is, for instance, between the skin of
the cart horse and that of the racer ! And there ap-
pears to be, in this respect, some connexion between the
cutis and the hair ; for the skin, as well as the coat, of

198

The Cutis.

a black horse are coarser and thicker than those of a
horse of the same breed of another color ; and it is ra-
ther uncommon to see a black racer, whereas the color
is predominant among our large, heavy, cart horses.
The skin is thinnest and softest in those parts that are
either thinly clad with hair, or are quite hairless : — such
are the lips, the nose, the interior of the ears, the bor-
ders of the eyelids, the inward part of the thighs, and
the generative organs.

The cutis vera itself is white ; its apparent color it de-
rives from the rete mucosum, of which we have evidence
in those horses in whom that membrane is also color-
less :— these are the milk-white and cream-colored
i*aces ; in pieballs, it appears white also in places where
the hair is white. But in order to show that the cutis
does not vary its color with the hair, it will be found
that, whether it be taken from a bay, a chesnut, or a
black, when deprived of its other constituents, the skin
in all will exhibit the same pale white aspect.

The cutis is of a fibrous texture, tough but supple,
elastic, very vascular, and highly sensitive. Its fibres,
which take every direction, are so intimately interwoven
and knitted together that it is a texture that has consi-
derable strength, a fact we have abundant proofs of
both in and out of the body ; and that these fibres are
elastic is plainly shown by its returning to its former di-
mensions after having been folded in those places
where muscular fibre can have no action upon it ; in
fact, by this property it is chiefly that the skin so
nicely adapts itself, both as a partial and general cover-
ing, to different parts of the body under the variations of
bulk and shape to which they are liable from position
and condition. From what I have been able to learn in

The Cutis.

199

my examinations of the cutis, I should say that its struc-
ture was substantially the same as that of the human sub-
ject. It appears to consist of a dense substratum of cel-
lular tissue, with which are interwoven fibres of a liga-
mentous nature, in such a manner that innumerable a7'eo-
like the meshes of a net, are formed in it : these areolae
open, by correspondent pores in the cuticle, upon its ex-
ternal surface, and are for the purpose of transmitting
thither blood-vessels and absorbents, of giving pas-
sage to the hairs, and of lodging the various emuncto-
ries and secretory organs of the skin.

Few organs are more vascular than the cutis — scarcely
can a pin be introduced into any part of it without draw-
ing blood ; but its vessels are small, indeed, generally
speaking, so minute that they do not carry red blood.
On close inspection of it, after the cuticle and hair have
been removed by maceration, multitudes of little rounded
eminences may be seen upon its outward surface, with de-
pressions between them : these are readily reddened by
injection with size and vermillion, and are resolvable
into vessels, nerves, and cellular substance. In allu-
sion to their shape they may be called papilleB ; but
they certainly do not deserve the name of papillsB «ervos<E :
they may be regarded as excretories of the perspirable
matter, and as points endowed with great sensibility j
but I do not consider them in the light of veritable or-
gans of touch. I know it is common, among professional
men, to say, that " the lips of the horse are his organ
of feeling, performing a like function to the fingers of a
man but I believe that this assertion is not well found-
ed : the lips most unquestionably have a more delicate
sense of feeling than most other parts; but may not
this be accounted for by their hairless and thin and
fine integument? Of most objects, the horse takes

200

The Cutis.

cognizance by inhalation ; and it is yet doubtful in my
mind, whether he can really be said to be in possession
of any veritable organ of touch: if he is, a peculiar ner-
vous structure similar to what endows our fingers, or
something like it, ought to exist about the muzzle ; but
it has only yet been verbally shown to us. The sole of
the foot is plenteously supplied with nerves — no part more
so ; but no horseman will contend that the animal can
feel any thing more through the hoof than the more ob-
vious properties of the surface upon which he treads !

The skin also abounds in absorbents. In places where
it is thin , the supei-ficial lymphatics, which are supposed
to take their origin from its areolae, are comparatively
large, and their trunks, in the subcutaneous tissue, are
readily found and injected : thus we see why the erup-
tions of farcy mostly make their appearance upon the
inside of the thigh and arm, about the breast, lips, and
sheath ; and why, when medicine is administered by
inunction, in the human subject, these are the parts
chosen for perfrication.

Of the infinity of pores which the skin has upon its
surface, probably the greater number transmit hairs;
but there are numberless others, smaller and conse-
quently less distinctly seen, from which a vapor is
continually emitted, the insensible perspiration, called
the perspiratory pores : the condensation and collection
of this exhalation, in form of diops of sweat, upon parts
that have little or no hair, serve to mark their situation ;
they may also be rendered visible by putrefaction or
maceration. Again, there is another set of pores of
larger size, more discernible in some places than in
others, which are the mouths of so many follicles : — the
nose has them of large size for the secretion of mucus ;
the auditory passages are furnished with many of them

The Cutis.

201

— the glandules cermninosa, from which issue a waxy-
matter ; and those parts of the skin subject to friction
are, in particular, beset with these pores : in fact, the
unctuous matter furnished by them every where pre-
serves it soft and supple, and in some places keeps up
a constant greasiness of the surface.

The skin at the bend of the knee and hock has a se-
cretion of this nature, which, from irritation, now and
then is augmented, and from want of cleanliness be-
comes inspissated, and collects about these parts, and,
if the incrustation be not disturbed, generates a foul
ichorous sore : lameness, of course, will result from this
whenever stiffness or pain is felt in flexing the limb.
When the bend of the knee is its seat, grooms call it the
mallenders ; but, when the front of the hock is thus af-
fected, the sallenders. Almost all our treatises on far-
riery contain some specific recipe for it. Nothing more
is required to be done however than to cleanse the part
from the scurf or scab that may infest it, by soaking it
in hot water ; and correct any morbid disposition the
skin may have to emit matter, differing in quantity or
quality from its natural secretion, by anointing it daily
with some astringent ointment *, which, at the same
time, will render it soft and pliable.

The skin of the heel of the horse, like that of the ax-
illa of the human subject, has very many of these
ij^Iandular pores ; through them oozes an unctuous se-
cretion, of a peculiar odor, to which the remarkable
softness and suppleness of that part is owing ; and an
unusual flow of this matter, somewhat altered in its
nature, gives rise to what the vulgar call grease.

* Yk Zinci Sulphat : Pulv: 3ij ungt: cetacei 5j f- ungent.

202

Cuticle.

New cutis is slowly formed, and appears to be so at
jio little expence to the animal economy ; at least Nature
never fails to make the old go as far as possible by ex-
tension, before the formation of new is commenced : in
the cicatrization of a large wound, for example, the old
skin first contracts from all sides to its utmost, in order
to leave as little space as possible to be covered by new.
And not only is it with difficulty formed, but its living
powers are weaker when produced than the old ; for,
though it appears to be veiy vascular at first, its ves-
sels, after a time, either shrink in calibre or, many of
them, become obliterated altogether: hence it is that
horses who have had exulcerated backs from saddle galls,
or fistulse, are always disposed to subsequent injury
in those places, where they are commonly marked by
patches of white hair. With regard to the reproduction
of cutis, it has been said, that " nothing but skin can
produce skin :" I am much mistaken however if I have
not seen, in the human subject as well as in horses,
cutis forming upon the granulations, in the very middle
of a sore ; which, by fresh depositions upon every side,
has met and coalesced with that growing from the old,
and thus considerably shortened the term of cicatriza-
tion.

Cuticle.

■ ^The cuticle, epidermis, or scarf skin, is a thin, tough,
inorganic membrane, that serves as an envelope to the
true skin. In the living animal it may be demonstrated
by the application of a blister : serum is effused from the
exhalents of the cutis, the cuticle in places is elevated
by it into little hemispherical bladders, vesicles, or hlis-
■ters, through the transpai'ent sides of which the straw

Cuticle. 203

color of the fluid is perfectly evident. Boiling water
will destroy its adhesion to the cutis, both in the living-
ad dead subject ; in the latter, they may also be parted
by putrefaction, and by long maceration.

The cuticle appears to be composed of very thin or
fine flexible scales, so disposed as to bear an analogy
to those of fish, which, in fact, are nothing more than
their cuticular coverings : this squamous structure is
best seen by viewing a piece through a glass that has
been peeled off" from a putrid surface ; it is also very
demonstrable in some stages of mange, in which the
cuticle becomes hard and dry , turns white, and des-
quamates in successive laminae.

The color of the cuticle is the same in all horses ;
whether they are black or grey, chesnut or bay : although
the surface of the skin appears (when the hair is shorn
off) to vary in hue with the color of the hair, the infil-
tration of serum from a blister underneath the cuticle
shows that this appearance is deceptive.

In most parts of the body the cuticle is thickly clad
with hair ; but there are places, which I pointed out
before, where we find it nearly or quite bare. Every
part of the cutis vera is covered by cuticle ; and it not
only insinuates itself into the perspiratory pores and
follicular passages, but lines to a considerable extent
ome of the outlets of the body. Cuticle passes into the
mouth and pharynx, and there gi'ows continuous with
'tie membranes of those parts ; it also enters the anus,
lid, some have thought, lines the whole alimentary
inal ; but that is not borne out by the nature of those
[)arts ; although we are not able to mark its precise line
of termination, so intimately is it united with their pro-
per linings : furthermore, it may be traced into the raea-

204

Cuticle.

tus auditorius externus. Bichat indeed is of opinion
that not only the cuticle, but the cutis itself lines these
cavities in man. " All authors," says he, " have admit-
ted an epidermis upon mucous membranes . But it would
appear that most of them believed that only this part of
the skin entered the cavities and lined them. Haller,
in particular, is of this way of thinking. But a slight
inspection will suffice to remark, that here, as upon the
true skin, it forms but a superficial covering to the
papillary surface and to the corion. Boiling water,
which detaches it from the palate, tongue, and pharyixx
even, exposes to naked view the two other strata of
skin*."

The cuticle is everywhere pierced with holes, which
correspond in size, situation, and number, to those of
the cutis. First, there are the pores for the hairs ;
secondly, the perspiratory or exhalent pores ; thirdly,
the absorbent or inhalent pores ; and fourthly, pores of a
larger size, through which unctuous secretions, in va-
rious parts, are emitted.

At one time it was believed that the cuticle was
formed by the chrystallization of a fluid effused from
the surface of the cutis ; but the simple fact of the
foetus in utero having a cuticle is a refutation of this
opinion. That it is however a deposition or secretion
from the cutis, the same as the hoof is from the sensi-
tive parts of the foot, seems not to admit of a doubt ;
and yet how the process of production is carried on,
no one has yet been able to discover. For every prac-
tical purpose, probably it is enough for us to know,
that, if from any cause the cutis vera be denuded, the

* Anatomic Generale, torn. iv. page 469.

Cuticle.

205

I uticle will be speedily reproduced ; from which we
umay conclude that its formation is neither difficult nor
eexpensive to the animal economy. It is destitute of
1 nerves and vessels *.

Being semi-transparent, color, as has been observed,
lis imparted to it by the subjacent skin ; and by parity
t of reasoning we must account for its assumed sensibi-
I lity ; for, in reality, the sensation which it appears to pos-
sess is solely attributable to its adhesion to the highly
sensitive cutis "underneath — the animal feels through it
and the hair somewhat in the manner that we do through
a thin furred glove. Those parts therefore where the cuti-
cle is thinnest, are, cceteris paribus, the most susceptible
of impressions : the lips and nose of the horse instance
this ; and, in us, the extremities of the fingers, in which
the proper sense of feeling is known to reside. That the
the cuticle itself has no senastion whatever, the simple
cutting of a corn in man is a sufficient proof of. Herein
may be said then to consist the chief use of the cuticle —

* " It has no perceivable circulation. The exhalents and absorb-
ents that traverse it, do not belong to it. No morbid appearance
that argues organic sensibility happens in it. It does not inflame ;
it is passive in all cutaneous affections, and never participates of
them notwithstanding its continuity. Corns (in the H. S.) and other
excrescences from it, are inert, dry like it, and without vascularity :
they are only painful in consequence of the pressure they give
to the nerves underneath, and not of themselves. No pain is ever
felt in the cuticle; it is worn by friction, like other inorganic bodies,
and (like them) is afterwards reproduced."

" From all this, its life is extremely obscure ; I doubt even that
it really has life. I feel inclined to consider it as a semi-organic
body, nay even inorganic, that nature has interposed between
foreign agents and the truly organised cutis, as a medium of inter-
course and gradation."— BiCHAT, Anatomie G'tnerale, torn. iv.

206

Rete Mucosum.

to protect the cutis from immediate contact with foreign
bodies or agents, and to moderate its extreme sen-
sibiUty.

The cuticle does not vary a great deal in thickness in
the horse, but in the human subject, in the palms and
soles, its substance far exceeds that of any other part : in-
deed, in the latter, it is very apt to grow morbidly thick in
places, the effect of external pressure, and this is the
nature of what is called a corn — a very different disease
from what has been absurdly so named in the horse's
foot. The only approach to a corn that we meet with,
are those horny or cuticular exuberances that grow
upon the inward part of the arms ; these however can-
not be regarded as morbid excrescences, for they are
unexceptionably present in horses, as well as in asses
and in mules.

Rete Mucosum.

The rete vel corpus mucosum consists of a fine, de-
licate, laminated tissue, that is intei'posed between
the cuticle and cutis, and regarded as their con-
necting medium ; so that the two parts I have been
describing are, in fact, nowhere in contact with each
other. It is to this substance that the skin owes its
color ; in proof of which, as I observed but now, if
either the cutis or cuticle of a black horse be examined
in its detached state it will be found to be, in itself,
colorless. Again, the cutis vera of the Negro is as white
as that of the European ; the only difference in their
skins consists in the color of the corpus mucosum, which
in the latter is black.

This part however is with difficulty demonstrable in a
separate state from the others— we may detach it by pu-

Rete Miicosim.

207

trefaction from the cuticle, but we succeed only with great
pains in stripping it from the cutis, and this is best at-
tempted by maceration in hot water : the skin of a black
horse, and a part bare of hair should be selected for the
jnirpose. It is, as its name implies, a viscous mucilagi-
nous matter, that clothes the delicate vessels and nerves
of the cutis in their way to the surface, and appears to
afford them some protection from outward impressions,
and to assist in preserving their integrity of structure.
It has been compared to the pigment of the eye ; and,
as far as their appearance is the ground of analogy,
certainly not without reason.

In most animals there appears to be a general rela-
tion in color between the skin, the hair, and the eyes :---
in black horses we invariably find the skin black, and
the eyes dark colored ; on the contrary, in the milk-
white and cream-colored breeds, the skin is white or
colorless, and the eyes red or ferretty. In brown, bay,
and chesnut horses, the corpus mucosum participates of
the color of the coat ; in pieballs, skewballs, &c. it
varies its hue in places with the change in color of the
hair. The Negro has black hair and eyes ; the Mulatto,
black hair and dark eyes ; the Albino (in whom by
some this substance is thought to be wanting) light
hair and red eyes.

This part, when destroyed, as it occasionally is by
abrasion or ulceration, appears to be with difficulty re-
generated, some say that it never is. We know that
after broken knees, white hairs are frequently seen
upon new skin ; but, in the course of time, (unless the
part go bare,) it is generally covered by hair of sai
uniform color with the coat ; this inclines me to think
that the corpus mucosum is reproduced. Again, new

208 Physiology of the Skin.

skin in the Negro is at first red — from its blood ; still
the cicatrix in the course of time acquires a dark hue,
and I believe, in almost every instance, ultimately takes
on a black tinge.

Thy&iology of the Skin.

1 HAVE already made several remarks relative to the
economy of this part ; I shall add but a few general
observations.

That the skin is eveiywhere acutely sensitive its
nervous texture would leave us no room to doubt,
were we not hourly convinced of it in a variety of ways
I need not particularize here ; but that any part of it,
I repeat, has a peculiarity in the arrangement of its
papillae, or pre-eminent tactility, resembling that which
resides 07ily in the points of our fingers or toes, is to me
as yet unproved. Girard says, " qu'elle regoit cer-
taines impressions speciales, et devient sous ce rapport
le siege du tact et du toucher," but he does not circum-
scribe either the seat of feeling or touch to any particular
part of the skin !

Moreover, the skin is one of the principal emunctories
of the body, from the surface of which passes off, as
insensible perspiration, certain serous matters infil-
trated through the exhalents of the cutis, which are
said to depurate the circulating fluids. That something
considerable is eliminated from the system through the
medium of the skin, is presumed by accurately weighing
an animal at different times, together with what is taken
in as food, and voided as fceces or urine : a considerable
loss of weight is soon detected that cannot be accounted
for in any other way than by admitting that fluid has es-
caped from the extensive superficies of the skin.

209

On the Hair.

■ The hair is that covering which Nature has provided
for the skin of animals to protect it from cold, heat, and
external injury : it is to be regarded as their clothes,
being in general suited in quantity and quality to the
temperature of the climate they inhabit. The cutaneous
surface in man, being for the most part but thinly fur-
nished with hq,ir, possesses a degree of sensibility, and
of relation to surrounding agents, which that of a qua-
druped is excluded from ; and in this respect, says
BicHAT, whose sentiments these are, life is less active
in the latter. In animals, the functions of reproduction
and digestion constitute the principal if not the only
sources of pleasure *. r.>
*, The horse is clad with hair of two qualities : the
one is that fine soft material which invests the body
generally, and which we expressively distinguish by
the term coat; the other, vulgarly known as horse-hdir,
is of a coarser and stronger nature, is confined to par-
ticular parts, and appears to have been added rather
for the purposes of ornament and defence than those
of vesture and interception. The mane, for instance,
forms a shield to the neck in combat ; and for this
reason, is more luxuriant in the male than in the
female : it is likewise— as well as the foretop which is
a continuation of it, an ornament f. The tail is not

* Anatomie Generale, torn. iv. p. 496.

t A singular variety in the production of mane presents itself in
a gelding, belonging to the Artillery. From the back, posterior to
the part covered by the saddle, is growing, for the space of tliree
inches, a row of horse-hairs, precisely similar in color and quality
to the mane, several of which exceed four incites in length.
PART II. r

208 Physiology of the Skin.

skin in the Negro is at first red — from its blood ; still
the cicatrix in the course of time acquires a dark hue,
and I believe, in almost every instance, ultimately takes
on a black tinge.

Physiology of the Skin.

I HAVE already made several remarks relative to the
economy of this part ; I shall add but a few general
observations.

That the skin is eveiywhere acutely sensitive its
nervous texture would leave us no room to doubt,
were we not hourly convinced of it in a variety of ways
I need not particularize here ; but that any part of it.
I repeat, has a peculiarity in the arrangement of its
papillae, or pre-eminent tactility, resembling that which
resides only in the points of our fingers or toes, is to me
as yet unproved. Girard says, " qu'elle regoit cer-
taines impressions speciales, et devient sous ce rapport
le siege du tact et du toucher," but he does not circum-
scribe either the seat of feeling or touch to any particular
part of the skin !

Moreover, the skin is one of the principal emunctories
of the body, from the surface of which passes off, as
insensible perspiration, certain serous matters infil-
trated through the exhalents of the cutis, which are
said to depurate the circulating fluids. That something
considerable is eliminated from the system through the
medium of the skin, is presumed by accurately weighing
an animal at different times, together with what is taken
in as food, and voided as fceces or urine : a considerable
loss of weight is soon detected that cannot be accounted
for in any other way than by admitting that fluid has es-
caped from the extensive superficies of the skin.

209

On the Hail'.

• The hair is that covering which Nature has provided
for the skin of animals to protect it from cold, heat, and
external injury : it is to be regarded as their clothes,
being in general suited in quantity and quality to the
temperature of the climate they inhabit. The cutaneous
surface in man, being for the most part but thinly fur-
nished with hair, possesses a degree of sensibility, and
of relation to surrounding agents, which that of a qua-
druped is excluded from ; and in this respect, says
BicHAT, whose sentiments these are, life is less active
in the latter. In animals, the functions of reproduction
and digestion constitute the principal if not the only
sources of pleasure *.

t; The horse is clad with hair of two qualities : the
one is that fine soft material which invests the body
generally, and which we expressively distinguish by
the term coat; the other, vulgarly known as horse-hdir,
is of a coarser and stronger nature, is confined to par-
ticular parts, and appears to have been added rather
for the purposes of ornament and defence than those
of vesture and interception. The mane, for instance,
forms a shield to the neck in combat ; and for this
reason, is more luxuriant in the male than in the
female : it is likewise— as well as the foretop which is
a continuation of it, an ornament f. The tail is not

* Anatomie Generale, torn. iv. p. 496.

t A singular variety in the production of mane presents itself in
a gelding, belonging to the Artillery. From the back, posterior to
the part covered by the saddle, is growing, for the space of three
inches, a row of horse-hairs, precisely similar in color and quality
to the mane, several of which exceed four inches in length.
PART 11. p

210

On the Hair.

only an admirable appendage, but it in some measure
supplies the deficiency of hands, in switching off insects
and other irritants within its reach. The tufts of hair
sprouting from the fetlocks, defend those parts from con-
tusion when they are forcibly depressed in action, and
serve at the same time as a protection to the heels. The
long bristly hairs standing erect from the muzzle and eye-
lids, are so many tangents of communication with the
delicate organs of feeling into which they are implanted.

The coat itself is not of an uniform thickness or con-
sistence in all parts. Upon the sides, the back, loins,
and quarters, and upon the shoulders and arms, it is
thick and abundant ; but upon the inward parts of the
thighs, and under the arms, it is thin and scanty. Upon
the genitals, udder, and anus, around the lips, and at
the entrance of the auditory canal, it is so soft and fine
that it takes on the nature of down. It is longest and
most luxuriant about the throttle, and within the ears ;
it is coarsest and most capable of resistance upon the
legs. The hair, generally speaking, takes an oblique
direction, either backwards or downwards, from a me-
dium line that would cut the body into equal halves : in
parts possessed of much motion — as the throttle, axilla,
flank, and bend of the knee and hock, it is rough, ele-
vated, and irregular in its course. Now and then we
meet with a horse in whom the coat is everywhere
frizzled or curled. More rarely, and only in certain
climates, are seen horses whose skins are hairless ; at
least, they have no other pilous covering than a light
down, which is only perceptible on close inspection *.
Dogs of this description are not so uncommon.

* Mr. Sewell, in the course of his visit to the continental Vcte-

On the Hair.

211

Whatever be the apparent nature of the hair in various
animals it does not materially differ in the most remark-
able circumstances connected with its structure. A hair
1 may be said to be composed of tjiree parts : the bulb, the
; »?oo?,, and the stem. The bulb co;isists of a transparent
I membranous canal, of a cylindrical figure, perforated at
' either extremity, that, has its origin in the adipose and
cellular tissue under the skin, is received into one of
the areolae or large pores of the cutis, and terminates
under the cuticle. The aperture through its base is filled
by a little conical papilla, from its softness denonaina^ted
the pulp of the hair, from virhich issues the root,, or the
tender part of the stem, which is included w^ithin the
bulb : this circumstance has led anatomists to regard the
stem as a secretion from the pulp. In the whiskers and
bristles of large animals, nerves as well as blood-vessels
have been traced into the bulb : to the latter we may
assign the production of an unctuous matter that
anoints the stem, and gives that sleekness and glos-
siness to the coat so remarkable in the Arabian horse
and his race; a deficiency of which appears to be the
prevailing cause of the dry and stubborn coat of a horse
out of health, or of one that has suffered from exposure
to cold. The stem, having emerged from the bulb, is
said to receive, in piercing the epidermis, a , covering
from it ; but, if it does so, friction soon destroys it, for

rinary Schools, met with, at that of Berlin, a preparation of " the
StufTcd skin of an African horse, which had not the slightest appear-
ance of a single hiiir upon it. It is of a rliin colour, and is no doubt
a particular genus," he adds. In consequence of the skin being in
a dried state, I suspect that the down upon it had become imper-
ceptible ; for I apprehend that the surface of it was not perfectly
bare during life. Mr. Sewell's '''Report."

p 2

212

On the Hair.

I have not been able to obtain any distinct demon-
stration of this tunic : Bichat indeed denies its exist-
ence altogether. Those who have subjected large quan-
tities of hair to chemical analysis have found its compo-
sition to be very similar to that of horn or cuticle ; but it
has been a matter of dispute vk^hether the stem is
formed of a single case, or vs^hether it consists of fila-
ments including two or more canals in their interstices :
from the obsei-vations of those who have most exten-
sively and minutely inquired into this part of com-
parative anatomy, it would appear that bristles and
what is called horse-hair are filamentous ; but that the
finer hairs are simply tubular. From the summit of the
pulp proceeds an elongation of soft matter into the ca-
vity of the stem, which, from its outward resemblance
to it, by many is regarded as a process or continuation
of the pulp itself ; but Bichat avers, that it is a dis-
tinct substance, and, though he acknowledges his ig-
norance of the true organization of it, maintains that it
is a vital part, and that it is the seat of the coloring
principle of the hair. For my own part, whatever may
be the nature of this particular substance I am inclined
to agree with the learned writer of the article " Hair"
in Rees' Cydopadia, " that the coloring matter per-
vades the horny tube of the hair, to which it communi-
cates an uniform stain or dye, in the same manner as
the substance of a horn or hoof is colored."

All hair has a common similarity in its structure and
mode of growth ; whether it assume the appearance of
human hair, that of the coat or mane of the horse, the
wool of the sheep, the fur of the rabbit, the bristles of
the hog, or the spines of the hedge hog : its particular
varieties in every one of these animals are owing to the

On the Hair.

213

rhickiiess and disposition of the fibres of its cuticular
case. The coat varies in quality, color, and length in
horses of various breeds : the Arabian, the racer of this
country, is characterized by his smooth, silken, and
:lossy coat : the cart horse, the Shetland poney, and
ihe northern horses in general, are contra-distinguished
by the greater length and consequent roughness, the
coarseness, and stubbornness of their hair.

With regard to color, I have already had occasion to
remark, that there is some connexion between that of
the skin, the hair, and the eyes : black horses have
black skins and dark eyes ; milk-white and cream-
colored horses, light skins and wall eyes. The three
primitive colors — those of which all the other appear to
be either shades or combinations, are white, red, and
black. According to Richerand, the lighter the shade
the finer the hair ; as a proof of which, he says, there
are fewest black hairs in a square inch of skin, more
chesnut, and most light colored. This assertion our
observation appears to confirm ; for it is comparatively
uncommon to meet with a black thorough-bred horse,
though it is a very prevalent color among cart horses ;
and the glossy silken coat for which the former is so
much admired is in none more conspicuous than in
these that are light coloured.

Most animals, I believe, at certain seasons of the
year, lose one pilous covering, to have it renewed or re-
placed by another. The pulpy substance at the root of
the hair shrinks and dries up, the stem consequently,
110 longer supplied with nourishment, loses its support
and falls off; at the same time, a new pulp appears by
the side of the old one, which, during the absorprion

214

On the Hair.

of the latter, grows and gives root to a new hair : so
that the pulp and stem only, and not the bulb, undergo
the process of regeneration. The coat of the horse is
shed twice during the year — in spring and autumn : a
phenomenon exhibited with great regularity so long as
the animal remains wild ; but as soon as he is domesti-
cated, this process is influenced by many circumstances
connected with his stable management ; though by
none more perhaps than the temperature of the stable.
That which comes under the denomination of horse-
hair— the mane and tail, and the long hairs about the
fetlocks, muzzle, eye-lids, &c. is never shed ; hence it
grows to an extreme length. One of the most striking
phenomena in the natural history of quadrupeds, is, that
in deer not only the hair but the horns are deciduous.
In the spring, the antlers of the stag, but now so strong
and formidable, becoine soft, and are cast off altoge-
ther, leaving him in a comparatively defenceless state ;
in the course of the ensuing summer, however, new
horns spring up in their places, which, before the
autumn has begun, crown the animal again with his
noble weapons, and give him his wonted majestic
inien, preparatory to the season of copulation which is
now at hand. And now, his horns being fully regenerate
and fit for the purposes of combat, with ungovernable
sensuality he wanders forth in search of the female,
whose possession, should another dispute with him, he
will by terrible conflicts strive to obtain and secure.

The hair is speedily reproduced upon any denuded
part ; so that we are not afraid of the skin remaining
bare \Vhen the cutis vera (and consequently the bulbs
of the hair) have not been injured : indeed hair will

On the Hair.

215

be regenerated though it be plucked out by the roots.
In the case of broken knees, however, it occasionally
happens that the contusion of the fall is followed by
more or less disorganization of the cutis, and then a scar
or bare place remains ; or a few light-colored or white
hairs only grow upon the place, which appear to be the
oiFspring of defective pulps.

The time of casting the coat, one that may be compared
to the moulting season in birds, is often the epoch from
which we may date the origin of disease, and always
that when more or less debility reigns in the system.
In October and November, people come to us and com-
plain, that their hunters, whose condition they have
fostered with so much pains, are weak and foggy,
-weat under moderate exercise, are swelled in the hind
legs, and are unusually sluggish and dispirited. Upon
inquiry we find that the animal is changing his coat ;
under which circumstances, we should advise that he
be temperately ridden, that his ration of corn be dimi-
nished and bran mashes substituted, and that he be
clothed warm in order to promote the growth of the new
coat : a little alterative medicine * may also be of ser-
vice in rectifying the digestive functions.
' On the other hand, the appearance of the hair may
Tbe adduced as a sign of internal derangement : such a
horse is " unhealthy in his coat" is an expression in
the mouth of every stableman ; and he generally has
recourse to a remedy which restores its smooth and
healthy aspect, without knowing at all the connexion
between the one and the other. The fact is, that this
is one of the most remarkable instances we have of the

* Vide Note, page 77, Part I.

216 On the Hait.

sympathy existing between the skin and the alimen-
tary canal ; and that we might ad infinitum bestow our
labor upon the former without effect unless we were
at the same time to direct our attention to the latter.
Here, a dose of physic, or what is better, some laxative
medicine, in conjunction with a soft diet, is required
to render the curry-comb and brush availing in redress-
ing and polishing the coat.

But there are other causes that may give rise to a
rough coat. Simply taking a horse into an atmosphere
colder than the one he has been habitually exposed to,
will make the hair stare ; even leaving the stable door
open to a current of air will do it, which the advo-
cate for a warm stable is no stranger to. Now, this can
be no other than the effect of contraction, not of the
skin itself, but of the muscular fibres which adhere to
it — the panniculus carnosus ; in truth, it is something
similar to what happens in the erection of the bristles,
though that is a voluntary act, while this is not at all
times dependant on the will : in the one case, cold is
the stimulus to contraction ; in the other, volition.

What I have just particularized are not to be
confounded with that variety of rough coat which a
horse acquires during the winter season at grass ; for
this consists in an increased growth of hair; and
hence it is, a fact well known, that a hunter stabled
with a long staring coat in the autumn, cannot be made
to look smooth and sleek, by any subsequent treat-
ment, until the ensuing spring. One of the best eluci-
dations of this is the hairy covering of the ass : when
we remark the different appearances which that puts
on in summer and in winter, we may with truth say,
that this animal has a coat suited to the seasons.

On the Hair.

217

Now and then indeed, from some cause or other, the
action of the cutaneous vessels being disordered and the
sliedding process arrested or but imperfectly performed,
the old coat, or some parts of it, remain on until the
<econd time of casting : when this is the case, the hair
Is said to be set.

Having proceeded so far in this interesting subject, I
shall conclude the lecture with a few observations on
the nature of a " good coat," and the means of pro-
ducing and preserving one. When the hair lies smoothly
;ind intimately upon the surface of the skin, when it has
a soft kindly feel, and a bright shining hue, it is said to
be a good coat. Now, that we may more clearly trace
out the causes to which this is owing, let us first
take a view of the circumstances under which it is pro-
duced. Horses that are natives of hot climates are in
general light coloured, and have all soft, sleek, and fine
coats : in a late communication from a resident in
Barbadoes, I find this passage — " the horses (which are
chiefly from Spain and America) are in the finest condi-
tion imaginable : t/ou may almost see to shave from the
rrloss upon their coats." From which indeed another fact,
provable by innumerable other instances, receives confir-
mation : viz. that an animal will vary the length and
quality of his coat according to the temperature of the
climate into which he is transplanted ; indeed some have
.rone so far as to say, that the different breeds of horses
are referable to such a change of circumstances. Let
this be as it may, we have ample evidence at home of
the truth of the first of these positions : every horse-
man in this country knows too well the change that is
to be wrought in the coat of his horse by warm clothing
to need more than the bare mention of it here, as con-

LECTURE XXXIII.

^s*s^ A>^w^> ^s^s^ ^s^^ r-r^ r-^^

On the Nose.

The nose, for the convenience of description, may be
divided into its hard parts, or those that compose its
exterior, and give shape and stability to it ; and its soft
parts, or such as enter more especially into the compo-
sition of the organ of smell. The hard parts consist of
bones and cartilages : of the former I have already
shewn the situation, connexion, &c. it now remains
for me therefore to give the anatomy of the latter.

'•The cartilages of the nose are five in number: — one
internally and centrically situated, divides it into two
parts or chambers; the other four, placed externally and
inferiorly, enter into the composition of the nostrils.
The first, named the septum narium vel nasi, is main-
tained in its place chiefly by the vomer, within the
groove of which its posterior edge is firmly fixed ; su-
periorly it is attached to the nasal plate of the os eth-
moides, and anteriorly to the ossa nasi, along the nasal
suture. The remaining four cartilages are fixed around
the upper and inner part of the nostrils : two of them
broad are placed superiorly, two narrow and curvated
outwards, below them ; they arc attached to, and suji-

On the Nose.

221

ported by, the extremities of the ossa nasi and the sep-
tum narium. These four cartilages serve to give shape
and substance to the nostrils, to keep them constantly
open, to admit of occasional dilatation of them, and to
defend the taper extremities of the ossa nasi from injury
and fracture, to which they would otherwise have been
continually exposed.

The internal parts of the nose, in the horse and dog,
are developed in a more determinate form, and on a
much larger scale, comparatively speaking, than in
man ; hence the acuteness of smell in these animals,
which to them appears to supply the place of that sense
of touch which we so eminently possess. The cavity of
the nose, I said, was divided into two chambers by the
septum, that have no direct communication with each
other ; and eaith chamber is subdivided by the ossa tur-
l)inata, which forai but imperfect partitions, into three
])assages, called meatus ; but which, in reality, are no-
Uiing more than so many longitudinal canals. Every
part of the chamber is lined by a dense, soft material,
of a pale red colour during life, denominated the pitui-
tary or schneiderian membrane ; which, within the nostrils
is continuous with the reflected integuments, and supe-
riorly, where the chambers open opposite to the pharynx,
with the membrane of that part : it also passes into and
lines the sinuses of the head, though there it puts on a
less vascular aspect. For, as I shewed in describing
the bones, all the sinuses — the frontal, the nasal, the
maxillary, the sphenoidal, and the ethmoidal, open by
distinct apertures into the chamber of the nose ; so that
the extent of surface of the schneiderian membrane,
more particularly if we take into our view the large
ize of the turbinator bones, which it also envelopes, is

222

Oil the Nose.

very considerable, and to this is chiefly to be attributed
that exquisite perception of odor which horses and dogs
are known to possess. This membrane has a very
close and firm adherence to the parts it covers by the
insinuation of its fibres into them ; indeed the very basis
of its structure is fibrous, with which is mingled a large
proportion of cellular substance, as a substratum and
medium of connexion for its glands, vessels, and
nerves : the inner surface of it appears to supply the
place of periosteum and perichondrium ; the outer is
more compact, is smooth and papillaiy, is eveiywhere
pierced by exhale nts, from which distils a limpid
fluid, and is strewed with numerous mucous folhcles,
whose secretion, by preserving its surface constantly
moist, sheathes and defends it from acrimonious in-
halations, and preserves its nice susceptibility of impres-
sion. It is well supplied with blood-vessels, which are
less numerous and smaller where it lines the sinuses, and
receives sensibility from two sets of nerves, whose rami-
fications are abundantly distributed to every part of it :
one set furnish it with ordinary feeling, the. other,
having its tender jamusculi interwoven in its papillae,
endow them with the faculty of smelling.

There are two ducts, that must not be overlooked, con-
nected with this organ. The ductus ad nasum, a tube
partly bony and partly membranous, which commences
at the inner canlhus of the eye, within the os ungius, runs
along a canal in the osmaxillai'e superius, and terminates
at the inner and inferior part of the chamber of the nose,
upon the common integument, about one-fourth of an
inch from its junction with the pituitary membrane : Uie
orifice of it is generally large enough to admit a crow's
quill. The second is the ductus comtnunis iiarium,

On the Nose.

223

which takes its course into the pharynx, under the vo-
mer, where it is formed by the union of two branches
that arise from oblong orifices in the floor of the nostrils.

This organ in the horse has two remarkable appen-
dices— two little pouches, or cuk-de-sac , above the ex-
ternal nares, known by the appellation of the false nos-
trils. They are composed of doublings of the common
integuments, but, except at their entrance, are without
hair. They freely communicate with the chamber of the
nose, and open externally, in common with them,
through the nostrils. Their use has not been discovered.

Within the cavity of the nose cognizance is taken of
those subtile effluvia — those odoriferous and inconceiv:-
ably minute particles which are conveyed into it through
the medium of the external air. To the exquisite per-
ceptivity of the schneiderian membrane, the organ of
^mell, do animals owe those delicate and delightful im-
pressions which enable them to pursue their prey, or to
ascertain the properties of such substances as are pro-
vided them for food : this it is that capacitates the dog
to follow the footsteps of his master, or pursue the
course of the swift-footed deer — to seek out the haunts
of game, or retrace his pad in an unknown country.
It is remarked in all quick-scented animals, that the
sinuses of the head are very capacious, and the ossa
turbinata large and prominent ; though it seems that
the membrane lining them does not possess so many ol- -
factory nerves as that spread over the chambers of the
aose, and consequently not an equal acuteness of smell.
There cannot be a doubt however, that the sinuses do
contribute very much to this faculty ; and it is gene-
rally thought that they do so, by retaining the scented

>irfor a much longer time than it could possibly have

i:mained within the nose itself.

224 On the Larynx.

The openings into this organ, both inferior and supe-
rior, are of large size, to admit of the free passage of
air to and from the lungs. That peculiar intonation,
neighing, the voice of the horse, is produced by the
forcible expulsion of air through the laiynx into the
chambers of the nose, where it is modulated by the
various impediments it meets with and the quivering
action of the external nares.

On the Larit/itx.

The larynx, placed at the top of the windpipe, be-
tween it and the root of the tongue, is that organ through
which the animal breathes, and produces that well-
known sound called neighing. Before I proceed to ex-
amine the larynx, I shall make a few remarks on the
anatomy of the os hyoides ; a bone I postponed the
description of in a former lecture in consequence of
its being more immediately connected with the parts
now before us.

The OS hyoides is a bone of a very irregular figure,
placed between the root of the tongue and top of the
larynx. It has been divided into three parts : — the
body, appendices, and cormia. The body, remarkable
enough, has the precise configuration of a common
spur, of which the semi-annular part is fixed around
the upper margin of the larynx, while the neck projects
forward in the throat, where it serves for the attach-
ment of the root of the tongue. To the posterior, round,
cartilaginous ends of the body, are fitted, by smooth
cartilaginous cups, the appendices — two processes, about
three inches in length, which take a direction upward
and forward : their union is effected by means of strong
capsular ligaments with synovial linings ; and' the ap-
pendices themselves furnish a place of origin to certain

On the Larynx. 225

muscles belonging to the tongue. The cornua begin
f rom the tops of the appendices, with which they have
an articular connexion similar to what exists be-
tween the appendices and the body, embrace the sides
of the pharynx, to which they give extensive attach-
ment and support, proceed along the branches of the
jaws, and are fixed by ligaments to the petrous portions
of the ossa temporum.

By the os hyoides then it is, that the larynx is re-
tained in its place, at the same time that a certain de-
ijree of motion is admitted between them, consequent
upon the performance of deglutition and the production

f voice. Regarding it situ, the larynx appears to be
entirely muscular ; for it is not only clothed with its own
muscles, but receives a covering, upon the sides and
upper and posterior parts, from the constrictors of the
phaiynx ; and we must divest it of both these coverings
in order to lay bare the cartilages, which we must ac-
quire a knowledge of before we can understand the at-
tachment and uses of the muscles. These cartilages
;ue five in number : — the thi/roid, cricoid, two arytenoid,
and the epiglottis.

The thyroid or shield-like cartilage, by much the
largest of the five, forms the superior, anterior, and
lateral parts of the larynx. It consists of two broad
lateral portions, continuous and prominent at the upper
and anterior part of the neck, the prominence correspond-
ing to which in human anatomy has received the name of
pomum Adami. Below this point of union the divisions
recede from each other, and leave a triangular space
between them, which is occupied by a ligament named
^he ligamentum crico-thi/roideum. The four projecting

ijmers from the posterior part of the thyroid cartilage

PART II. o .

226 On the Larynx.

are named its coitiua : the two superior are joined by
capsular articulations to the body of the os hyoides,
the two inferior are connected by very short capsular li-
gaments to the cricoid cartilages ; and the union of all
these parts receives additional strength from expansions
of membrane. At the roots of the superior cornua are
two foramina that give passage to nerves, of consider-
able importance, to the interior of the larynx. This car-
tilage not only composes the chief part of the larynx ;
but, as its name indicates, incloses and shields from
external injury all the others.

The cricoid or ring-like cartilage is placed below the
thyroid ; but the broadest part of it is behind, where it
overlaps the first ring of the windpipe somewhat in the
form of a helmet ; from which indeed in front, in conse-
quence of having become narrow, it is only distinguish-
able by its situation. Upon its broad or posterior part
are four surfaces of articulation : — the two upper receive
the hinder extremities of the arytenoid cartilages, the
two lower are adapted to the inferior cornua of the
thyroid cartilage : they are all furnished with capsular
ligaments and synovial membranes. Moreover, it is
attached by ligamentous expansions to those parts, and
to the first ring of the trachea.

The two arytenoid or ewer-shaped cartilages, of trian-
gular figures, lie over the upper and back part of the
windpipe, leaving an aperture between them leading into
that canal, denominated from its proximity to the tongue,
the glottis. Their inward parts are everted, and form
a triangular prominent border over which is spread the
membrane of the glottis; their outward surfaces are
marked by concavities in which are lodged the arytenoid
muscles. They repose upon the cricoid cartilage be-

On the Larynx. 227

hind, with which they have capsular articulations ; and
in front have a membranous connexion with the carti-
lage next to be noticed.

The epiglottis, so named from being raised over the
o lottis and occasionally covering it like the lid of a pot,
is well adapted from its heart-like shape to the rima
glottidis : whose margin is now completed by two narrow
slips of cartilage that proceed from the base of the lid to
the aiytenoid. By some, these cartilages have been
separately considered ; but in my opinion improperly so ;
for they are, in truth, nothing more than prolongations
or appendices of the epiglottis. The laryngeal face of
this cartilage is smooth and concave, and covered by
m extension of membrane from the glottis ; that part
opposed to the tongue is unevenly convex, and is tied
to that organ, as well as to the os hyoides, by a doubling
f membrane infolding some muscular fibres : to this
niusculo-membranous ligature, which assists in retaining
the cartilage in its elevated position, unless when it is
momentarily pressed down in the act of deglutition, and
in subsequently raising it again into its place, the name
o^framim epiglottidis is properly given. The fraenum re-
ceives co-operation in this function from strong elastic
ligaments that connect the base of the epiglottis to the
t hyroid and arytenoid cartilages.

If we detach the epiglottis, or raise it forcibly in
ijrder to obtain a more complete view of the rima glot-
tidis, the latter will be found to be stretched into an ob-
long quadrilateral figure, whose width gradually diminish-
es from the middle towards either extremity, and bears a
ratio of about one to six when compared to its length.
The sides, turned forwards, are formed by the arytenoid
cartilages ; those directed backwards, by two prominent

q2 ■ .

228 The Muscles of the Larynx.

folds of membrane, (which envelope the thyro-aiytenoid
muscles,) commonly described as the vocal ligaments,
from their being concerned in the formation and intona-
tion of the voice. Immediately above each of them is
a slit-like aperture, opening into a membranous sac
large enough to contain a walnut : this is one of the
ventricles of the larynx, whose use is also connected
with the production and modulation of the voice.

The membrane lining the cavity of the lai'ynx is one
of great susceptability ; on which account it is kept
continually moist by a mucus, oozing from numerous
lacunae — the excretory orifices of small subjacent follicles
whose situation is denoted by the little round eminences
upon its surface. This is the common seat of the
catarrh that is accompanied with cough.

The Muscles of the Larynx
ApE eight pairs and a single one.

Thyro-Hyoideus arises from the semi-annular por-
tion of the OS hyoides, passes downwards and back-
wards, decreasing in breadth in its descent, and is in-
serted into a little eminence upon the side of the
thyi'oid cartilage.

It will elevate this cartilage, and with it the whole
larynx ; or it will depress the os hyoides.

Ckico-Thyroideus. a small muscle of a trian-
gular figure placed below the former. It passes from
the side and front of the cricoid cartilage to the under
border of the thyroid — lying in the space between them.

It has the power, in action, of approximating these
parts.

The Muscles of the Larynx. 229

Ckico-Arytenoideus Posticus has an extensive
fleshy origin from the broad part of the cricoid cartilage,
iirows narrow in its ascent, and implants itself by fleshy
and tendinous fibres into the posterior part of the aryte-
noid.

To pnll the arytenoid cartilage backward.

Crico-Arytenoideus Lateralis is concealed from
view by the inferior cornu of the thyroid cartilage. It
arises from the upper border of the cricoid cartilage
along its side, and terminates in the posterior extremity
of the arytenoid, below the place of insertion of the
foregoing muscle.

This muscle, in action, will dilate the glottis, by se-
parating the arytenoid cartilages.

Thyro-Arytenoideus is the largest of the aryte-
noid muscles. It lies between the thyroid cartilage and
membrane of the larynx, and adheres to both of them.
It proceeds from these broad attachments to the inward
part of the thyroid cartilage and the triangular ligament
in front of it, (where it is divisible into two portions,)
and is extensively inserted along the side of the aryte-
noid cartilage.

It will enlarge the glottis by separating the arytenoid
cartilages, and tighten the membrane it adheres to in
its course.

Arytenoideus. a small muscle that runs from
the posterior part of one arytenoid cartilage to the cor-
responding part of the other.

It will contract the glottis by approximating these
cartilages.

ArytkxNo-Epiglottideus. a small muscle taking
its course from the arytenoid cartilage to the epiglottis.

230

On the Trachea.

To shut the glottis by depressing the lid.

Thyro-Epiglottideus. Aslendermusclethat runs
from the thyroid cartilage to the epiglottis.
It will assist the former.

Hyo-Epiglottideus. This, the single muscle of
the larynx, lies embedded in fat and a doubling of
membrane at the root of the epiglottis, between it and
the body of the os hyoides. It takes its origin from the
spur-like portion of that bone, and is fixed to the broad
part of the epiglottis.

This muscle is not placed here to maintain the ele-
vated position of the epiglottis, its own elasticity being
fully adequate to that ; but it will still further retract
that cartilage, and thus considerably enlarge the open-
ing of the glottis. It does this more effectually, and
to a much greater extent, when those muscles co-ope-
rate that draw the arytenoid cartilages from each other.

On the Trachea.

The trachea, or windpipe, is that cartilaginous tube
which extends along the neck, from the larynx to the
lungs, for the conveyance of air. In horses of the ordi-
naiy size it is from twenty-five to thirty inches in length.

The trachea commences from the inferior border of
the cricoid cartilage, opposite to the body and trans-
verse processes of the atlas, takes its course along the
anterior and inferior part of the neck between the
sterno-myloidei muscles, (which by their approximation
conceal the lower portion of it,) and enters the chest
between the two first ribs ; where, beneath the curva-
ture of the posterior aorta, it divides into two parts,
named the bronchia^.

IFI

On the Trachea.

231

From fifty to sixty annular pieces of cartilage enter
into the composition of the windpipe, which constitute
a structure so remarkable for the inequality or asperity
of its exterior, that the ancients, in order to at once
distinguish it from all other vessels, called it the
iispera arteria. No entire or undivided tubular substance
could have partaken of the various motions of the head
and neck without having suffered more or less distortion,
and consequent deformity and diminution, of some part
of its canal, which would have been attended with
frequent interruptions, dangerous and even fatal, to
the respiratory functions ; whereas, constructed as it is,
with the aid of its muscular power, no attitude in which
the animal may naturally put himself, will impede the
passage of air through it. The cartilages, or, as they
are commonly described, the rings of the windpipe, have
all a close resemblance to one another : if there be any
disparity between them worthy of notice, it consists in
those that form the superior part of the pipe being
somewhat larger and broader than those nearest to the
bronchise *, A ring is not uniform in its breadth, in
consequence of having waving or scolloped borders ;
the advantage of which is, that a sort of dove-tailed
connexion is effected which materially contributes to
the compactness and strength of the entire structure.
Its front and sides measure, in the broadest places, half
an inch in breadth, and nearly a quarter of an inch in
thickness — evidently made so substantial to resist exter-
nal injury ; whereas its posterior or unexposed parts grow

• Now and then we find, at the upper part of the tube, two or
three or more of these rings accreted together : it gives rise to some
prominence thereabouts generally, and may be perceived by taction
in the living animal.

232

On the Trachea.

suddenly thin and yielding, and taper to the extremi-
ties ; which, instead of meeting and uniting, pass one
over the other, and thus fonn a shield of defence behind,
while they admit of a certain dilatation and contraction
of the tube : here a ligamentous expansion, mingled
with cellular membrane, unites and so invests these
attenuated terminations of the cartilages that we are
unable to make out their ultimate disposition until this
substance has been cleared away by the knife. The
rings are attached to one another by narrow ligament-
ary bands, strong and elastic ; which, after the rings have
been drawn apart in certain positions of the head
and neck, have the power to approximate them :
when the pipe is removed from the body and sus-
pended by the uppermost ring, these ligaments counter-
act the tendency which its weight has to separate the
rings, and still maintain them in apposition. The low-
ermost ten or twelve pieces of cartilage appear on
examination but ill to deserve the name of rings ; in-
deed they are little more than semi-annular, the defici-
ency behind in each of them being made up by an inter-
mediate moveable portion of cartilage, whose breadth
increases as we descend, which is let into the vacuity,
so as to overlap the terminations of the segments,
where it is confined and concealed by the ligamentary
and cellular investment before noticed.

Where the outward extremity of the ring suddenly
turns inward and degenerates into a thin flexible flap
on either side, a band of muscular fibres is fixed and
stretched across the canal, which divides it into two
unequal semi-elliptical passages : — the anterior one is
the proper air-tube, the posterior or smaller one is
filled with a fine reticular membrane that connects

On the Trachea.

233

♦ his band to the posterior part of the ring, and keeps
It, in action, from encroaching upon the main conduit.
This self-acting band appears to me to have been added
J the tube to enable it to enlarge its calibre — not to di-
minish it, as a superficial view of these parts might
lead one to imagine ; for in consequence of the passage
being naturally elliptical, and the muscle being extended
across its long diameter, the contraction of its sides will
u^ive the tube a circular figure, by increasing the curva-
ture of the ring anteriorly, and thereby, in effect, will
expand and not contract the canal. I would say, then,
that the trachea was made muscular in order that it
might have the power of increasing its capacity for the
passage of air, whenever the lungs were called into ex-
traordinary action : in addition to which, I think, that
this band, in some degree, may counteract any tendency
that certain positions of the head and neck have to alter
its shape and diminish its calibre. This opinion is cor-
roborated by the circumstance, that the muscle grows
slender and pale as we approach the lower end of the
jnpe, where the canal itself is nearly circular, and where
it is placed in the least moveable part of the neck *.

The trachea is lined by a soft, pale red membrane,
which anteriorly has a close adhesion to the rings
themselves, and presents a smooth polished internal
surface ; but which posteriorly is loosely attached to the
muscular band, and puckered into fourteen or fifteen
'ongitudinalj5/2c<8 or folds, that extend with regularity

* In the physiology of this part, I find I am at variance with
Oihard. The French professor ascribes to it the power of contract-
fi/? the calibre of the trachea. "Cette couchc, bien evitlemment
nnisculcuse, pcut retrecir le cahbre de la trachee, en rapportant
' s extremites des segmens." Anat. Vet. p. 146 ct 147. torn. II.

234

On the Trachea.

from one end of the tube to the other. These folds
were evidently made to allow of the contraction and
elongation of this muscular band ; for I cannot myself
assign any reason why they should exist in its relaxed
state, unless this fulness of membrane be given to admit
of enlargement of the calibre of the tube during the con-
tractions of that muscle : if this be plausible, I may ad-
duce the corrugation of the membi-ane as another proof
that the calibre of the trachea is susceptible of augmenta-
tion. This membrane is continuous with that which
clothes the rima glottidis ; but it is paler than it, and not
near so sensitive. Its arterial ramifications, which are
also less abundantly distributed over it, exhale a vapor
from its surface ; independantly of which, it is kept
continually lubricated by mucus, furnished from its nu-
merous lacuna, which defends it from any thing acri-
monious that may be contained in the breath.

The trachea having entered the thorax bifurcates into
the two bronchia: — of them, the right is the more capa-
cious tube, from having communication with the larger
division of the lungs ; the left the longer one, in conse-
quence of having to cross under the posterior aorta, in
its course to the left division of the lungs. The last
cartilage of the main pipe has a spear-like or angular
projection extending down between the bronchiae, which
fills up that space that would otherwise be left open fiom
the divergent manner in which they brancli off : it is very
moveably attached in order that these tubes may ac-
commodate themselves to the motions of the neighbour-
ing parts. The bronchias vary in structure from the trunk
that gives origin to them : instead of their rings being
formed of entire pieces of caitilage, they are constituted
of several portions, making up so many segments of the

il

Thr/roid Glands. 235

circle, that overlap one another, and are united to-
Li, ether and invested by an elastic cellular substance :
t liey also differ in having no muscular band, another
I act connected with the physiology of that part. The
Ix onchiae in penetrating the substance of the lungs sub-
divide— the right into three principal branches, the
eft into two ; from which spring innumerable others
hat grow smaller and smaller, until ramifications so
minute are produced that they are not traceable by
ihe naked eye. In the larger branches we may dissect
out five and even six segments of cartilage, which are
held together by a thin, but dense and elastic cellu-
lar substance; in the smaller divisions, only two are
found, and they are diminished in size ; and in the
smallest visible ramifications of all, cartilage is altoge-
ther wanting, though, in many places, marks of the
rings may be seen upon the continuation of the lining
membrane, which here composes the entire parietes of
the tube. In the larger branches this membrane, which
is continuous all the way through the bronchial system,
assumes a plicated disposition — apparently, to admit
the more readily of distention.

Thyroid Glands.

Two egg-shaped, apparently glandular bodies, at-
tached just below the larynx to the sides of the wind-
|iipe, and united in front of it by an intervening portion
if the same substance, which, by way of distinction, is
by some called the isthmus. They are enveloped and re-
' lined in their situation by cellular membrane, are larger
ud more vascular in the young than in the old sub-
ject, and exhibit a spongy texture when cut into, which
1 1 am at present ignorant of the precise nature of They

236 Diseases of the Air Passages. — On Catarrh.

are well supplied with blood-vessels, and have many
small nerves going to them. Their physiology still re-
mains obscure.

Diseases of the Air Passages.

In this stage of inquiry, I shall confine my observa-
tions to the two common morbid affections of these
parts : — catarrh and roaring.

On Catarrh.

A CATARRH, in common language a cold, may be
said to consist in a defluxion of mucus, or of mucus
mixed with pus, from both nostrils, which is generally
attended with glandular tumor, and often with cough
and more or less febrile action.

I have stated, that the membranous lining of the air
passages is kept continually moist by a sero-mucous se-
cretion, of which, I may here remark, in a perfectly
sound condition of the part, more is not produced than
is required for that purpose ; and so rarely is mucus
discharged from the nose without some present or pre-
vious inflammation of the membrane, that its emission
is generally regarded (and probably this is as good a
line between health and disease as can be drawn) as
symptomatic of unsoundness. There is a thin, aqueous
distillation from the nostrils occasionally to be seen in
health, especially after exertion, but this is mostly de-
rived from the lachrymal duct ; and there may be a flake
or two of pure white mucus apparent, lodged just within
the ala of the nostril, but this is also occasional : were
it continually succeeded, after having been removed, by
a similar appearance, whether the schneiderian mem-

r II

On Catarrh.

537

une were apparently inflamed or not, I should unhesi-"
ilingly pronounce the organ to be unsound.

I think that the nature and symptoms of catarrh will
;« best understood by describing it under three stages-
a the first or incipient stage, an acrid watery secretion
1 ickles from the nose, mingled with some white flaky
iiucus, which is commonly accompanied with redden-
iig of the schneiderian membrane, and tumor of the
ubmaxillary glands : cough is rarely produced thus
arly. In the second stage, which succeeds the first
generally in the course of three or four days, the watery
luxion has ceased, the mucous become copious and
hick, and often yellowish from the admixture of pus,
he membrane is deeply and generally reddened and is
ery irritable, the submaxillary tumor is prominent and
ender, and a loose and sonorous cough is occasionally
leard. And now a mild fever generally comes on : — the
Liiimal appears unusually dull and heavy, he moves
luggishly, his head is not carried with his ordinary
inimation, or he may hang it and let his eyelids droop,
us appetite is commonly impaired, his pulse is about
)■')" or 60°, and his body is disposed to be costive. In

Idition to these, there are other symptoms which,

>m being present only in certain cases, may be re-
garded as occasional. Soreness of the throat may be a
prevailing symptom ; and when it is, the animal, from
xperiencing pain in the act of swallowing, refuses to eat
1 to drink much, and gentle compression of the gullet
VI 11 make him instantly flinch and will excite violent
oughing. One or both of the parotid glands may tu-
"lefy and grow tender to the touch ; and these swellings,

t hey show a disposition to continue swollen, often ter-
Niinate in abscess. Now and then, when the fever runs

238

On Catarrh.

high, the respiration becomes disturbed, the pulse rises,
the superficies of the body grows cold, or feels very hot,
and the animal is evidently laboring under constitu-
tional derangement : in such cases, the chest is very
apt to become the chief seat of disease, by metastasis,
or, as I believe, through the inteiTention of the wind-
pipe. Though this is the ordinary course of the disease,
variations are always to be met with ; but as they are
all related in their general character, they need not par-
ticularization *. I shall reserve to the conclusion of
this lecture what I have to say about the third or chro-
nic stage.

In the primary stage, the inflammatoiy action appears
to be confined to the pituitary membrane ; as soon
as it pervades the membrane of the glottis, it is ma-
nifested by cough or symptoms of sore throat, or by
both : if it extend down the windpipe, punilent mat-
ter is generally discharged from the mouth, as well as
from the nose, in the act of coughing, and it often runs,
without any expulsory effort, profusely from the latter
when the head is made the dependant part.

Touching the theory of catarrh, the production of the
undue quantity of the natural sero- mucous secretion of
Schneider's membrane, is attributable to an augmenta-
tion in the supply of blood to it ; the purulent commix-
ture, to some unknown variation or alteration in the ac-
tion of its supplying vessels. The thickened state of
the membrane, (not commonly perceptible until the dis-
ease is advanced in the second stage,) by which we ex-
plain the dyspnoea occasionally present, is owing to

* Horses are seldom shown to us before the commencement of
tlie second stage: in some, the primary stage is altogetlier wanting.

On Catarrh.

239

his plethora of the vessels, -and to interstitial effusion,
I mode they have of relieving themselves of distention ;
\nd the cough results from the preter-natural excitability
of the membrane, and more particularly of that part of
it which covers the rima glottidis.

Those of the present day who maintain that the
exciting cause of catarrh is a suppression of that
blood which ought to have passed off in the form of
cutaneous evaporation, and the consequent repulse
of it upon the membranes of the respiratory passages,
must not seek for confirmation, or exemplification of
their theory among horses, as the following notorious
tacts will show : — Two undomesticated horses out of
three, under five years of age, that are taken from cold
situations and kept in warm stables, and fed upon the
ordinary ration of provender, will receive catarrh.
Whereas, if the same animals, after having recovered,
and become naturalized to their warm abode and new
habits of life, be, under similar circumstances, exposed
us formerly, whatever other disease the sudden vicissi-
tude of temperature may be productive of, the proba-
bility is that not one, (even though there were fifty of
them,) vyill catch cold. But, even domesticated horses,
that are advanced in years, and that have been accus-
tomed to such changes, do not always escape, unless
some precautionary measures be taken ; for hunters,
when they are taken up from grass in August and Sep-
tember, in cold seasons, unless due attention be paid to
tlie temperature of the stable, and their clothing and
regimen, are often the subjects of catarrhal attacks.
Now and then this disease follows violent exercise, and
it is most likely to do so at a time when the horse is

^40

On Catarrh.

hot in adequate condition and wind. The practice of
allowing sweating horses to stand long in exposed situa-
tions in cold weather, while the rider is regaling himself
or performing his business within doors, and then of
suddenly renewing their suppressed perspiration, one
<vould say prima facie must be hurtful in the extreme ;
and yet we daily see the animal obnoxious to the most
trying changes of this description (and I am really
astonished how his constitution bears up against their
pernicious tendency) with apparent unafFectedness.

I have heard veterinary surgeons talk of influenza,
and (though rather unlearnedly) of epidemic catarrh
among horses. Catarrhal affections, as well as pneu-
monic, are almost always prevalent among young
borses from November to March, or April ; and are ge-
nerally more or less so according to the rigor of the
season ; they also, in some years, attack great numbers
of horses about the same time, when the weather has
been unseasonably cold, remarkably changeable, or on
a sudden has become sultry : in fact, by noticing the
vicissitudes of the weather, and attending to the cir-
cumstances of locality, under the influence of which
the disease has been engendered, we may often very
rationally account for its origin ; but if we give up our
minds to assigning the cause to that about the nature of
which we are as ignorant as we are destitute of proofs
or foundation for such an assertion, we shall bewilder
ourselves, and mislead them who look up to us for
instruction.

The treatment of catarrh is very simple. If there be
no concomitant febrile action, or but little, the confine-
ment of the horse for a few days in a stable of a mean

On Catarrh.

241

; ud unifoim temperature *, (with attention to the clean-
iiuess of it,) warmly clothed, and fed with bran mashes
HI lieu of corn, with the aid of a few doses of laxative
and diuretic medicine will restore him to health : at
the same time, if there be much submaxillaiy tumor,
or any cough, or soreness of the throat, an ounce or
more of the injusum lytta should be rubbed either under
the jaw, or about the throttle. If the horse purge
;ifter having taken a few of these balls, let them be re-
mitted for three or four days, and afterwards adminis-
tered but once in the course of twenty-four hours. But,
s-hould febrile irritation manifest itself in the system,
f rom two to four quarts of blood may be detracted,
according to its activity, and either, what I call, the
svdative ball J exhibited, or hellebore in combination
with aloes ^. Many practitioners are in the habit of
lileeding, almost invariably, in catarrh. Although there
IS nothing directly injurious in the practice, still it is
< iften uncalled for ; when there is much reddening of
t he membrane, with but little discharge, and a diy hard
lugh, I am an advocate for venesection. There is
rtainly one advantage in bleeding early, which is, that
: 1 is seldom necessaiy to bleed again. The blister, in most
I ises, ought to be repeated about once or twice a week,

* About 50" of Farenheit.
t R Aloes Vulg. Ext. 311.

Hydrarg. Submuriat. grs. x.

Resinae Flavse 3ij.

Saponis Mollis q. s. ut. ft. Bol. semel velbisdie sumendus.
X Vide Note, page 79, Lecture v. Part I.
§ R Rad. Veratri Pulv. gr. x. ad 9j.

Aloes Vulg. Ext. 9j.

Resina; Flava 3j .

Saponis Mollis q. s. ut. ft. Bol. bis terve die sumendus.
PART II. K

242

On Catarrh.

The duration of the acute or inflammatory symptoms
of catarrh, even if the disease be allowed to take its
course, will seldom exceed ten days or a fortnight ; but,
then, it is very apt to run into the chronic or third
stage, more especially if the case have been neglected,
and this may prove tedious, and sometimes difficult to
get rid of. The animal feeds well, is in good spirits,
and appears to enjoy health, and yet a copious efflux of
thick, white, and perhaps grumous matter, shows itself
at the nostrils, now and then only at one of them, which
nothing we can employ, either locally or generally,
seems to have any influence on : this gleety condition of
the membrane is every now and then followed by
unequivocal symptoms of glanders. The remedies I ge-
nerally have recourse to here, are — some tonic drench *,
occasional doses of laxative medicine, a rowel under
the jaw, or (what Mr. Sew ell recommends) setons
along the face, two or three feeds of beans in the cours
of the day as a substitute for corn, and moderate exer
cise in the open air. Fumigation with the muriatic
nitric, or oxy-muriatic gases, I have seen occasionall
useful. In cases in which cough and tenderness abou
the throttle have been connected with the gleet, I have
experienced good effects from the application of a blister
along the course of the windpipe, from the jaw nearly
to the sternum, and its repetition once a week : here
the fumigation is inadmissible.

* R Ferri Sulphatis 3ft. ad ^.

Infusi Sem. Lini Ibift. Solve ut. f. Haust dandus semel
vel bis die.

LECTURE XXXIV.

On Roaring.

OARING may be defined to be, a peculiar unna"
iral sound made in respiration.

To one whose ears are familiar to this sound, any at-
^mpt to describe it may appear supererogatory ; and to
;ie who is unacquainted with it, no description can
3nvey just notions of all the variations of it that
ccur in practice. We are not only told of roarers,
lit we hear of pipers, wheezers, whistlers, high-blowers,
nd grunters : a cant in common use among our horse-
ealers and horse-men, of the vulgar meaning of which
o professional man should show ignorance. And though
leir cases are often confounded in practice, and not
;ldom, I believe, are dispatched without any discrimina-
ve investigation at all, still theVeterinaiy Surgeon ought
) be prepared to encounter these monsters at all points ;
nd therefore, I shall venture on an outline of the cha-
' ter of each of them, in relation to the degree and
culiarity of the sound, though I am apprehensive I
all but faintly trace those nice points of distinc-
on which the appellations themselves appear to demand.

R 2

244 071 Roaring. j

Pipers, I shall take the liberty to dismiss altogether
from this description, for they do not, strictly speaking,
belong to the genus of roarers : the word is only admit-
ted here by way of contrast, and I have satisfactorily
traced its popular import to broken wind.

The wheezer is admitted to be a species of roarer ; but
his disease, I am very much inclined to think, is
seated in the lungs ; the wheezing noise he makes,
very like that emitted by the human asthmatic, differs
from the sonorous respirations of other roarers in this —
that it is a common attendant on rest, and consequently
may be often heard in the stable : in all cases, it is dis-
tinctly audible as soon as the animal is walked or trot-
ted out.

With the whistler's note we soon become acquainted.
Whoever has listened to " the northern blast rushing
through a crack in the window- shutter," need seek no
description of it. In this instance, the sibilation appears
to be produced by a continued rush of air through some
narrow pass in the trachea or larynx ; it is seldom
or never heard, therefore, in a state of quietude, nor
is the common practical test of roaring infallible here :
when suspicions are awakened of its existence, I know
of no means so likely to compel the animal to disclose
this imperfection as a pressing gallop up hill. One
well-marked instance of this variety of roaring I have
met with in the human subject : a young gentle-
man, an acquaintance of mine, who had suffered much
from a violent attack of cynanche laryngea, used to fetch
his breath so hard, though with more apparent than
actual labor, in walking fast up hill, and with a noise
so in unison with the pipe of the whistler, that, when I
first heard him, I turned myself suddenly round under

On Roaring. 245

an apprehension that a horse of this description was ap-
proaching at full speed at my heels.

A high-blower is a horse that under moderate exertion

Iraws his breath hard and with apparent difficulty,
and makes an unnatural puffing noise, at every respira-
tion, which, it strikes the bye-stander, is produced by the
nostrils. And I believe that in these cases, if they are
iienuine, the impediment is to be sought after in the air
passages of the head ; whence the dilated nostrils,

and the sonorous puffs from them, when the animal's
breathing is accelerated.

The grunter is so called from the utterance of deep-
seated murmurs, or sounds that bear a comparison with
the grunts of a hog. This noise in the breath is not al-
ways generated under ordinary exercise ; it is oftener
produced by a sudden respiratory effort, the effect of
some unexpected event : a sudden clap of the spur while
riding, or an unlooked-for lash of the whip while driv-
ing, will often call forth one of these ejaculations.
We must take care however not to confound this affec-
t ion with the occasional grunts of a horse whose bowels
are distended with air or food, or whose body is loaded
with fat for want of work, nor to mistake for it those
sounds which proceed from a tight collar : these latter
are only temporary inconveniences, and often arise
under ordinary exercise, whereas this is mostly a per-
manent and an irremediable annoyance, and is only pro-
ducible with laborious or violent respiration. In my
opinion, this is a pulmonary disease — a sequel of in-
flammation : I have lately met with a well-marked case
that was immediately preceded by an attack of jmeu-
monia chronica. This species of roaring very often eS'
capes observation.

246 On lloaring.

The roarer, or, as he is often designated, the confirmed
roarer, utters his complaint more clamorously than any
of them to whom I have had occasion to append a de-
scription : he is so vociferous, w^hen his respiratory
actions are violently exerted, that he unequivocally
proclaims, in loud and insuppressible boations, his dis-
tressing malady to all around him.

Having endeavoured to point out and distinguish the
various species of roaring that are met with in prac-
tice, I shall now make mention of the methods com-
monly resorted to for their detection, and aftemards
attempt to show how far veterinary pathology has dis-
covered their seats, or coupled their symptoms with
certain morbid appearances.

In order to elicit that sound in the breath which is the
test of this disease, it is necessary, generally speaking,
that the animal be excited to make a sudden or forcible
respiratory effort. Now, it has been a question of
late (I wonder it was never agitated before) whether
roaring is an act of inspiration or expiration : some
steadily maintain the old positions and say that it con-
sists in an expiratory effort, while others venture upon
new ground and contend that it is an accompaniment
to a violent inspiration. As frequently happens in like
disputes, I believe that both parties are in the right, and
that the circumstances of the case only require to be
examined to prove it : e.g. if the horse is a high-
blower, or, in other words, if the impediment to the
passage of air is seated in the chambers of the nose,
the sonorous puffs, we hear, are so many expiratorif
acts ; whereas, if the obstruction is in the trachea or
bronchiee, the roaring sounds are sighs or i?i$pirations ;
and when the glottis is narrowed, and sometimes indeed

On Roaring. 247

when the trachea is, the noise may be produced both by
the ingress and egress of air, then however it is generally
loudest in inspiration. Any instantaneous shock, or
cause of alarm, hard galloping — especially up hill, and
the excitation of coughing, are the common trials to
which the animal is subjected to make him roar ; in-
deed, the most ready mode of proceeding is that in
vogue with our copers : it consists in making a feint to
strike the horse upon the body with a stick or whip,
and in doing it suddenly and unawares, and with as
much earnestness as though you were actually going to
knock him down, at the same time that you are holding
him short and fast by the head with the left hand. Al-
though these are the most ready expedients we can adopt,
1 agree with Mr. Sewell in not considering them as the
most worthy of reliance, and consequently in regard-
ing them as inconclusive in many cases that are no
confirmed roarers ; actual and continued corporeal exer-
tion is occasionally required to extort the sound ; and
the practice of putting such horses in harness and
making them pull heavy loads up hill, is after all pro-
bably the best trial that we can make of their wind.
Simply the act of coughing is a veiy indecisive test of
roaring ; and now and then, as the Assistant Professor
I astly remarked to me, the laiynx being in part or wholly
i)ony, coughing cannot be excited at all by compression
of it ; though then to an experienced tact, the very
inflexibility of it is a presumptive proof that the disease
13 present.

In entering upon the ratio , ^ymptomatum or theory of
1 oaring, I may observe that it bears an analogy to
croup, both in relation to the proximate cause and to
the parts afiected ; but we must be on our guard not to

248 On Roaring.

carry this comparison too far, or it will lead us into
serious pathological error ; for, although I may broadly
assert that the proximate cause of roaring is grounded
in cynanche trachealis, the inflammation does not put on
that type which makes croup so formidable and dreaded
a malady in a human being, nor is it confined to the
years of immaturity. When roaring does happen in
colts, it generally exists as a mode of termination of
strangles : the catarrhal affection that accompanies
strangles now and then continues long after the wound
in the throat is closed up, leaves the laryngeal mem-
brane thickened and perhaps ulcerated, and thus lays
the foundation of this disease.

But, not only catarrhal affections, many that are con-
sidered as inflammation of the lungs, terminate in roar-
ing ; for, in truth, the symptoms of this species of
membranous inflammation are not, at all times, so diag-
nostically marked as to enable us to steer clear of this
error ; and what renders cynanche trachealis infi-
nitely more obscure and insidious in its attack and
course, is, that irx the majority of cases the inflam-
mation is of that mild chronic type which is apt to
escape the notice of those to whom we must look for
the first reports of ill health : and hence it is, that we
are continually meeting with so many roarers in whom
nothing is known about the inflammatory action to
which they owe their present malady. Seeing, then, that
cynanche trachealis is the common fore-runner of roaring,
and that upon our knowledge of the one must mainly
depend our competency to treat the other, I shall detail
here the symptoms by which its existence is indicated.

Under an acute attack of cynanche, the horse breathes
short and quick, but, at first, generally with more pain

On Roaring. . 249

Uian embarrassment; he emits sudden and often sono-
rous puffs from his tense and dilated nostrils, and at
every inspiration exposes to view the septum deeply
imbued with its own blood; his pulse is small, hard,
and frequent ; he has paroxysms of coughing, occasional
guggling or rattling in the throat, and defluxion of pus
f Vom the nose ; and the lightest pressure upon the
larynx, or grasp of the windpipe, very much annoys him
and induces the cough : added to which, he has the other
(irdinaiy concomitants of febrile commotion. In some
cases, when the inflammation is at its height, spasms of
ihe larynx come on, during the continuance of which
respiration is carried on with so much distress that the
animal is, every now and then, threatened with sufl^j-
oation ; or the breathmg may become embarrassed
tVom a thickening of the membrane where it lines the
. glottis.

Did the disease commonly manifest itself in this acute
Iform, there would be no room for doubt, as to the
mature and tendency of the case ; but, as I observed
Ibefore, it approaches and creeps on in that insidious
may that the foundation of roaring is actually laid be-
lifore it is discovered that the proximate cause — inflam-
i mation, has been present in the air passages : at least,
.«so it is with the generality of cases. Were the animal,
ffrom the first, placed immediately under our own eye,
»we should probably be able to detect some signs that
» would raise our suspicions of what was going on : such
»aB, an unusual protraction of, or a fresh attack very like,
a a chronic catarrh, accompanied with soreness about the
t throat, perhaps some rattling or guggling noise in it,
and a hard cough ; disturbance of the respiration and
I pulse — short wind ; little or much purulent defluxion

250 On Roaring.

from both nostrils ; and increased susceptibility of the
trachea and laiynx on compression.

The causes of cynanche will, of course, be such as
give rise to catarrhal and pulmonary affections in ge-
neral ; in fact, as. we have seen, it often turns out to be
an extension or a sequel of the former, and may exist as
a precursor of the latter. But there is one fact con-
nected with its etiology, which, if borne in mind, will
often throw much light on the nature of . the case, and
enable us to frame in our own minds a pretty correct
diagnosis ; and that is, that a large proportion of these
subjects are harness horses — horses whose necks have
been rainbowed by the bearing rein for hours together,
and whose larynges have been compressed, and tracheas
distorted, by this unnatural and constrained position of
the head and neck.

It may be remarked here, that simple flexion of the pipe
itself, from the forcible and continued incui-vation of the
nose towards the chest, has been known to produce roar-
ing. Mr. W. Goodwin, Veterinary Surgeon to his Ma-
jesty, informed me, that, during his professional avoca-
tions at St. Petersburgh, his attention was especially
drawn to several horses, who by himself and others had
been declared to be roarers, in consequence of their
having got rid of their complaint in the manage. These
horses, it appears to me, roared from unnatural flexure
of the windpipe ; and this distortion the Russian system
of equitation, which consisted in the continual elevation
of the head and projection of the nose, was well adapted
to counteract, and in process of time remove. The in-
convenience, at first, is only temporaiy ; the intervals
of relaxation give the parts an opportunity, for a time,
of recovering their wonted tone and shape ; but repeated

On Roaring. 251

'ud long-continued acts of such violence may so enfeeble
their elastic powers, that permanent deformity of the
iarynx or pipe may result, and the malady become an
irremediable one. Mr. Sewell, with much reason,
censures the practice of buckling neck -straps, or the
t hroat-latches of collars and bridles, tightly : it is obvious
that all this is uncalled-for and wanton mischief, not to
add cruelty.

Mechanical injury, then, is one of the most frequent
causes of roaring ; and it may be either di proximate one,
as in the case we have just been examining ; or it may
be an exciting cause, as in the case of cynanche. It is
-aid, by some, that the practice we have of making
horses cough by compressing their throttles is apt to in-
Juce roaring ; but I do not think myself that the conti-
nuance or repetition of this act is such as to do harm,
legarding it either as one that may permanently deform
the pipe, or as a common mechanical excitant of in-
liammation; and therefore I do not consider it, in
itself, as one of the causes of this disease.

Having, thus far, considered the symptoms and ex-
citing causes of cynanche, and examined one of the im-
mediate or proximate causes of roaring itself, let us pass
< >n to particularize, and endeavour to account for the
origin of, others which dissection has discovered to us.
Cynanche may terminate in a variety of modes, and in one
I a- other of these terminations may be said to consist al-
uiost all the proximate causes of roaring that remain to be
<lescribed. The most common effect of inflammation of the
iir passages, is a thickening of the lining membrane ;
which, if it happen in that part of it that lines the cham-
I 'crs of the nose, will give rise to that thickness and pur-
inessin the breath in which consists the complaint of the

252 Qn Roaring.

high-blower. But the part where this increment offers
the most impediment, and consequently creates the great-
est inconvenience, is the glottis, the fissure of which
is very sensibly diminished by the morbid thickness
of its lining ; and thus is produced roaring, or confirmed
roaring, or, if the opening be much contracted, whist-
ling. Though the calibre of the trachea may also be
equally diminished by this interstitial deposit into
its membrane, it admits of some doubt in my mind
whether this, of itself, can be adduced as a proximate
cause of roaring ; but, if the same deposition pervades
the bronchiae, it may either be productive of thick wind,
or of wheezing. In horses in whom this state of parts
has existed long — probably several years, the membrane,
in consequence of undergoing a gradual organic change,
assumes a variety of morbid aspects : it may be found sim-
ply thickened ; or thickened, opaque, and white ; or
thickened and indurated, or corrugated, or reticulated, or
tuberculated, or ulcerated ; these last alterations how-
ever may proceed from another source . We now and then
hear of cases, of most of which I am inclined to think
that this is the pathology, that become roarers by me-
tastasis: Mr. Cowahd, Veterinary Surgeon, Royal
Artillery, related to me one of a horse of his own, in
whom extensive tumefaction and suppuration of the jugu-
lar vein followed the operation of venesection, which was
succeeded by abscess of the parotid gland, and termi-
nated by disease of the larynx and permanent roaring.

The next morbid appearance met with, in point of
frequency, is a band or distinct layer of adhesive matter,
which is thrown across, or adheres to, some part of the
larynx or windpipe. The situation and disposition of this
solid efiusion vary much ; sometimes a band is simply

Oti Roaring. 253

formed across the passage, or that is joined by another^
generally coming from the back part, by which the canal
divided into two or three passes ; at other times,
the deposition is seated in the cellular interstices be-
tween the muscular band and the rings, so as to protrude
the former and thus narrow the main conduit. So that
the adventitious substance here has not the disposition,
nor does it put on the appearance, of that found in
croup. This state of parts is also productive of confirmed
roaring *.

Tumors of any kind seated within or in the vicinity of
the air passages, may, by partial obstruction or compres-
sion of them, prove to be causes of roaring. What is
most commonly met with, is an abscess in the throat
that presses more or less upon the epiglottis ; and this oc-
casionally creates very alarming symptoms, and would
bring on suffocation and death were not the operation,
termed bronchotomy, (which I shall hereafter describe,)
had recourse to. Mr. Sew ell met with a case of
roaring in which he found an exostosis, growing from
the cervical vertebrae, between the two first ribs, that
pressed upon the windpipe.

Another and not a very uncommon cause of roaring,
is a wasting, or, in some instances, a total absorption
of one or more of the small muscles of the larynx. I
have lately examined a horse of Mr. C y's, a re-

* In the museum at this place is a preparation in which the
muscle has been displaced by the formation of a cross-band of ad-
hesive matter between it and the posterior part of the tube, by
which the interspace is divided into two passes, one of which is
large enough to admit a walnut, the other a hazel nut : the horse it
was taken from, breathed with great labor under exertion, and,
even when but moderately exercised, roared aloud.

254 On Roaring.

markable instance of it : in his larynx, upon the near
side, the crico-aiytenoideus posticus, was very pale,
and shrunk to half its original size ; the crico-arytenoi-
deus lateralis, the thyro-arytenoideus, and the aryte-
noideus, were altogether colorless, and scarcely recog-
nisable as muscles ; but their antagonists, upon the
other side, were unusually red and strong. Now, these
muscles, contracting in pairs, are all employed in dilat-
ing the glottis ; but, if one set act by themselves, this
orifice is not only distorted, but actually diminished
in dimension, in consequence o^ the arytenoid car-
tilage of the opposite side being drawn over it : thus it
is then that roaring is here produced. How we are to
account for these changes — to what original cause refer
them, is as yet unknown : by some, they are loosely
spoken of as the ultimate consequences of paralysis, or
of spasm ; but, though these tales may satisfy their
employers, they are no more, to the profession, than the
baseless conjectures of their authors, and as such are
deserving of no comment here.

A frequent concomitant, and occasionally a cause, of
roaring in old horses, is ossification, partial or complete,
of the larynx : the thyroid cartilages commonly take on
this change of structure ; the others however in the ad-
vanced stage often partake of it. But rarely do we meet
with any bony accretion of the rings of the windpipe :
now and then, we detect osseous depositions in some of
them, but I do not apprehend that any, or but little,
inconvenience is thereby occasioned.

I have already shown that the tracheal canal is very
subject to distortion from the injurious practice of reining
in ; about six months ago I saw a wet preparation from
the appearance of which I feel little hesitation in add-

On Roaring. 255

ing, that the canal may be mis-shapen from original
mal -formation. In this specimen, the passage was
triangular, the sharp angle was turned forwards, the
flaps of the rings posteriorly over-lapped one another
much beyond what was natural, and the membrane
throughout was thickened : there cannot exist a doubt
that the animal, it was taken from, was a roarer, and
most probably an inveterate one.

White has found out that an ulcer in the larynx is a
cause of roaring : I wonder he did not find out, much about
the same time, as the inference lay so straight before
him, that, if this were true, many horses acutely glan-
dered must be roarers too ! The simplest fact in the
physiology of roaring is this — that, to produce it, the
respired air must meet with impediment or obstacle
somewhere in its passage ; and so, unless this position
be groundless, a bare ulcer in the larynx has just as
much to do with the act as an ulcer in the tail. I dare
say that White has seen ulceration of the larynx, and
so has every one who has been in the habit of dissecting
these subjects ; but, it appears, that he has not perceived
the tumidity or thickening of the membrane which is so
common a concomitant of that state, and therefore he
idds, just as superficially as, it seems, he examines, this
was " the only morbid appearance to be found."

Doubtlessly there are other pathological varieties con-
nected with the production of this disease ; but I believe
that I have described them that are most useful to us, as
guides in our daily practice. The chief considerations
are — that there must be contraction of the air passage,
or partial obstruction in it, somewhere ; that according
to the degree of narrowness, and the situation of it, cocteris
paribus, will be the kind and loudness of the sound ;

5256 Oil Roaring. 1

and that upon the power of restoring the capacity of
the passage must depend the efficiency of our remedies
towards removing the evil. With a view of ascertaining
the degree of constriction necessary to the production
of roaring, and of watching the symptoms of pain or
uneasiness evinced by it, I passed a hgature of broad
tape around the windpipe of an ass, about one-third of
the way down the neck. The tape was first drawn with
moderate tightness, and the animal roared when made
to trot ; the pipe was then compressed to about half
of its natural calibre, and the animal whistled : in
both states the sounds were loudest in inspiration. At
length, I drew the ligature as tightly as possible ; in
about a minute afterwards, the animal, after having
staggered about much, fell, struggled violently, and,
apparently in great agony, expired in a sudden convul-
sive throw of the body upon one side, about two minutes
after he had fallen. I found the membrane of the wnid-
pipe reddened and covered with frothy mucus : the
passage was not completely obliterated ; I could still
pass a crow's quill through the constricted part of it.

I have heard Mr. Coleman say, in his lectures,
that roarers are generally sound-winded horses, and, so
far as regards the healthy state of their lungs, I agree
with him ; but it is a fact well known to people who
are in the habit of riding with hounds, that roarers are
always more distressed in the chace than sound horses,
and that they cannot bear to be hard pressed up hill ;
and the experiment I have just related, while it corrobo-
rates, serves to elucidate this point.' For, it would ap-
pear, that not only are sound lungs essential to a full and
healthy respiration, but that a clear and uncompressed
passage is also absolutely necessary to it ; and that, how-

On Roaring, 257

ver disproportionably large the calibre of the trachea
may seem when contrasted with its narrow entrance, the
jlottis, a very trifling contraction of the former, will
create noise enough in the breath to convince us that
there is a degree of embarrassment in the performance
of respiration. Moreover, I shall now show, that the
/inigs themselves may be the seat of roaring. Some
years ago, a horse, belonging to the Artillery, was
treated by my father (who is the Senior Veterinary
Surgeon of the Regiment) for violent roaring. The
aeck was repeatedly blistered ; it was also fired ; but
no relief was given. So painful was it to hear this
.mimal roar, when he was even led out of the stable, that
bronchotomy was tried ; but without benefit. At length,
1 he animal suffered so much from pain and distress in
breathing, that, being in that condition useless and found
insusceptible of relief, he was destroyed. There was
detected no thickening of the membrane — no disease
whatever, in fact, of the larynx or trachea ; but the
lungs were hepatized throughout their substance, and
the smaller divisions of the bronchiee, in many places, so
compressed that they were hardly pervious. I know
that this case is not reconcileable with the opinions of
the day ; and therefore I set the greater value upon it :
it is one also that is admirably calculated to silence the
trumpery of those who are continually persuading
people that thei/ can cure roaring horses.

Let us now pass on to the treatment of roaring.
Some of my professional cotemporaries have contended
hard for celebrity with the obstacles that are encountered
in this alluring field for experimental research ; but,
they would have spared themselves much labor if they
iiad (and it is generally the nearest road to a cure, after

PAUT IT. s

258 On Roaring.

all,) directed their investigations vigilantly, but pa-
tiently, to the cause instead of the removal of the dis-
ease. Which of them, I should like to know, can atte-
nuate a thickened and indurated membrane ? — or which
of them, by tying up a horse's head, and confining it
for a twelvemonth in that position, can remove an or-
ganized band that crosses the passage? — in a word,
which of them can proceed secundum artem to cure a
disease of the nature of which he, by his own confession
or silence, is either doubtful or ignorant? Clater,
who surpasses White by half-a-score of editions —
ergo, according to his own account, just so much in
excellence *, presents us with a very innocent recipe for
the dispersion of these trifles : — a few aniseeds and
carroway seeds ; and a little Dover's powder, mixed with
balsam of sulphur, and the yolk of an egg; which toge-
ther will take just as much effect upon the animal as
looking in his face will, or as White's squills, ammo-
niac, and aniseeds, will in broken wind. I need not
expatiate on such statements : I trust I have said enough
to expose the baseless fabricatio« of them, and to con-
vince scientific practitioners of the necessity of in-
vestigating causes before they proceed to unravel or
remove effects.

When a roarer is brought to us then, it behoves us to
take every means in our power to ascertain the special
nature and stage of his disease ; to which end, we ought
to inquire narrowly into the history of the case, and
make ourselves acquainted with every little circumstance

* " The rapid sale of twenty-three large impressions of this work
has established its character upon the surest foundation." Every
Man his own Farrier, by Fhanc. Clater; the 24th Edition.
Vide Introduction.

Oj* Roaring. ^5^

connected with it, before we proceed to examine the
horse himself ; and in doing this, we must take care to
attend to the sound that is uttered. Having formed our
diagnosis, the treatment to be pursued will naturally
suggest itself. >
If it be a case in which deformity of the windpipe
can be felt, and there appear reason to believe that it
owes its production to forcible incurvation of the neck,
the continual elevation of the head, and the confinement
of it by side lines, or the frequent bitting of the animal,
so as to project his nose fomard, are means well worthy
' of trial : we must not forget however that the success of
this experiment will depend upon the duration of the
I complaint ; nor must we overlook any inflammatory
: action that may be present in the system, which might
I prohibit such measures.
3 This, I believe, is but rarely the state of the case
1 however ; almost always, if the affection be recent, have
iwe to combat with inflammation, of an acute or chronic
Ikind ; the remedies for which, as it so often assumes the
(Catarrhal form, I need but recapitulate here. Venesec-
ttion is generally required in the chronic stage ; but, if
tthe cynanche be active, it is imperiously demanded : the
f frequent repetition of it too, is an excellent practice.
.'Active purgatives — nauseating and diuretic medicines
idn the intervals — and blisters along the who lelength
I of the windpipe, that are kept discharging, are to be
iiesorted to : no rules can be laid down for their judi-
(dous use ; that must be left ta the discrimination of
tthe practitioner. When active depletion is no longer
^admissible, counter-irritation often proves of great ser-
»vice : it should be persevered in by a renewal of blisters,

s 2

260 On Roaring.

or by inflaming the skin covering the pipe with the
actual cautery — a practice I myself do not approve of,
or by the introduction of setons.

When the animal roars to that degree that respiration,
even in a state of quietude, becomes a painful and labo-
rious duty, or that he is threatened with suffocation, we
have I'ecourse to an operation which consists in making an
opening into the larynx or trachea, and has been named
bronchotomy . When the larynx is to be opened, the liga-
mentum crico-thyroideum is the part chosen for incision ;
but of the windpipe any of the rings may be slit open
crosswise : the place of operating must, of course, depend
upon the site of the obstacle or constriction in the pas-
sage. The aperture may either be a simple longitudinal
incision, through which a metallic or flexible canula can
be introduced ; or it may be made square or circular ia
itself, by excising a portion, an inch in diameter, of the
ligamentum crico-thyroideum, or a section, an inch in
breadth, of two of the cartilaginous rings of the tra-
chea, in which case no tube is required : the latter
mode of operating is now generally practised. While
this temporary relief is afforded, we ought to make trial
of every means in our power to remove the obstacle to
respiration ; for, unless this be wholly or in part effected,
the animal must eventually relapse into his former, or
even a worse state of suffering.

Some years ago, there was quite a professional mania
for performing bronchotomy ; and, from what I can
learn, it sprung up from the successful excision of one
of those bands of lymph which cross the windpipe. I
have not been fortunate enough to meet with the parti-
culars of the case, nor the name of the operator ; but,

On Roaring: 26 1

admitting the truth of it, it is evident that this was al-
together a fortuitous event, and that all the credit that
was due to him arose out of the dexterity he evinced in
the operation, and that no little discredit was due to
them who were silly enough to suppose that they might
make a similar discovery wherever they chose to cut
a hole into the windpipe. Had I any reason to suspect
that this was the state of the rational mode of

procedure appears to me to be this : — first, I would
make an incision through the ligamentum crico-thyroi-
deum ; secondly, unless this relieved the roaring, I
would make another into the middle of the windpipe ;
ind lastly, if the animal still continued oppressed, I would
upen the pipe as low down as I could. By this means,
supposing there was a band of lymph, or any other local
obstacle, we might ascertain the exact site of it, and, by
the introduction of a long whalebone probe, probably the
nature of it : the propriety of extending these incisions,
(which should be only longitudinal slits in the tube,)
and the means to be adopted to remove the obstacle,
must, of course, rest upon the judgment of the operator,
l.et us not forget however, that the principal design of
this operation, is to afford instantaneous relief to the
animal laboring under great distress in breathing, or
threatened with suffocation; and that it can only prove
e ffectual when the obstruction or constriction is above
I lie place in which the opening is made.

LECTURE XXXV.

On the Viscera of the Thorax.

T?HE viscera which are inclosed within the cavity of the
chest, and are distinguished as the organs of respiration
and circulation, are performing functions immediately
concerned in the support of life ; and though it be an
indirect mode of demonstration, we may, in some
measure, convince ourselves of their vital importance
by a survey of tJiat cavity in which they are placed.
Attached above to the bodies of the dorsal vertebrae,
they are well fenced and defended on either side by the
arches of the ribs, and the cartilages ; while below and
before they are protected by the keel-like projection of
the sternum, and behind are opposed to the diaphragm,
which forms a musculo-tendinous partition between
them and the viscera of the abdomen : by these means.
Nature has not only shielded them from external injury,
but has secured to them the uninterrupted performance
of their respective functions.

Having opened the cavity of the chest, we perceive
a considerable vacuity between its parietes and the con-
tained viscera ; a circumstance which, as I shall hereafter
point out, is wholly referable to the unnatural condition

On the Pleura.

263

of these parts ; for, in the living animal, (and also in
the dead before the chest is opened,) this cavity is com-
pletely filled by its contained organs : so that, in fact,
in the natural state there is no vacant space whatever in
the che^t ; and we are not perhaps, strictly speaking,
justified in using the word cavity at all.

The contents of the chest consist of the pleura, me-
diastinum, and lungs ; and of the pericardium and
laeart : in addition to which, it contains several large
blood-vessels and nerves, the thoracic duct, and some
<mall glands.

On the Pleura.

The pleura is a thin semi-transparent membrane,
lining the cavity of the chest, and giving a covering to
I the lungs. By that portion of it which is called the
1 mediastiymm, the cavity is divided into the right and
I left sides of the thorax.

If I expose the lungs, by breaking off one or two of
! the ribs, we shall perceive that their surface, as well as
1 that of the cavity itself, is every where smooth, polished,
and humid : this is owing to the extensive investment
of the pleura, the interior of which I have now prsented ;
so that, in truth, if I introduce my hand, I am unable
to touch any part but pleura ; although, from its ex-
; treme tenuity and pellucidity, the viscera appear, on a
» superficial view, to present to me their own bare exte-
1 rior. Its outside, on the contrary, is^ rough, having
» numerous cellular flocculent appendages, by which it is
united to the parts it invests : and so close and firm are
• these adhesions, that to cleanly detach it, in the recent
' sttbject, is a difficult and very tedious dissection.

The pleura is a reflected membrane ; by which I mean.

264

On the Pleura.

one that not only lines the cavity in which the viscera
lie inclosed, but, by duplicature, or what in anatomi-
cal language is called reflection, gives a partial or com-
plete covering to the contained organs themselves. It
is evident, therefore, that such a membrane admits of
division into two portions : — a lining or parietal, and a
reflected portion; which, with regard to the pleura,
have, for the sake of more accurate description, re-
ceived the names of pleura costalis, and pleura pulmona-
lis : they are both however continuous at all points, are
precisely similar in structure and function, and, in fact,
are still but one and the same pleura.

There is yet a third portion of this membrane to which
a distinct appellation has been given, and that is the
mediastinum ; it differs from either of the others in
being composed of two layers, which are derived from
the two pleurae of the opposite sides of the chest ; for the ■
pleura even constitutes this membranous partition. If
we conceive the pleurae of the two sides of the thorax to
be perfect sacs or bags, the flattened sides of which are
closely applied and united together, in such a manner
that the double membrane formed by their union ex- ,
tends through the middle of the chest, from the dorsal
vertebrae to the sternum, we shall at once have a tole-
rably correct idea of the formation of the mediastinum.

The pleura, from the nature of its secretion, is one of
those included in the list of serous membranes, to which \
it has been demonstrated also to be similar in its inti-
mate organization ; like them, it presents a shining se-
creting surface, of a whitish aspect, and considerable
transparency, and is composed of little else than con-
densed cellular substance, whose texture is penetrated
by blood-vesRels, absorbents, and nerves : by long ma-

On the Pleura.

265

eration in water, indeed, it may be entirely resolved into
cellular membrane. In most parts it is extremely thin,
aand by no means tough ; but it is not so in all, for that
[portion which faces the diaphragm is much denser and
jstronger than the pulmonary or costal division of it.

The arteries of the pleura, which come from the ad-
jjacent parts, are in the natural state exceedingly small,
1 and admit only the colorless parts of the blood — a cir-
I cumstance that accounts for its pellucidity ; under in-
tflammation, however, they contain red blood, and are
the cause of that arborescent vascularity upon the sides
of the chest in horses that have died of pneumonia; than
which state nothing can better demonstrate the com-
parative number and distribution of these blood-
vessels. The majority of them terminate in exha-
lent orifices, from which is continually poured upon
the contiguous surfaces of the smooth interior of
the membrane, a serous fluid, in the form of steam or
vapor, which may at any time be rendered visible by
opening the chest of an animal recently dead. The ab-
sorbents of this membrane are very numerous ; and
though their extreme exility prevents us from de-
monstrating them in a state of health, yet may they
often be seen in considerable numbers in horses that
die of dropsy of the chest; we have also abundant
proofs of their existence from various phenomena that
occur in the diseases of the part : we know, for instance,
that these vessels take up the serous fluid effused in hy-
drothorax, for they have been found full of it after
death ; and it is a fact that no longer admits of doubt,
that blood, extravasated into the chest, is absorbed by
the mouths of these minute vessels.

The nerves of the pleura are too small to be traced by

266

On the Pleura.

dissection ; but, though it is not possessed of much sen-
sibihty in a healthy state, we know, at least we presume
from analogy, that it is highly sensitive in the diseased ;
for few diseases are more acutely, painful in the human
subject than pleurisy, and we have every reason to be-
lieve that horses suffer much from the same malady.

I have said that the exhalents of the pleura secrete a
serous fluid, which is emitted, in the form of an exha-
lation, or vapor, into the cavity of the thorax ; and
that you may see it at any time, if an animal, recently
dead, be opened while yet warm ; or, if an opening
be made into the chest of a live animal : in either
case, a whitish steam will be perceived to issue from the
interior of the cavity. This vapor, shortly after death,
becomes condensed and converted into a liquid ; so that
we always find the contiguous surfaces of the pleura
moist, and a collection of more or less fluid, resembling
water, in the most depending parts of the cavity. In
consequence of every part of the membrane being be*-
dewed in this manner, the lung itself may be said to be
in an insulated state, for the pleui-a costalis does not,
philosophically speaking, touch the pleura pulmonalis,
nor is the latter in actual contact with the mediastinum ;
all friction therefore, in the motions of these parts, is
by this interfluent secretion effectually prevented. In
this, then, consists the chief use of the pleura, viz. to
furnish a secretion, for the purposes of lubrication and
facility of motion, which it further facilitates by its ex-
treme glibness of surface : it is said also to answer
the purpose of ligaments to the contained organs,
thereby confining and strengthening them. The use
of the mediastinum is to divide the chest into two
compartments.

267

Diseases of the Pleura.

Although the horse is more disposed (as well as the
uunan subject) to diseases of the viscera of the chest
han of any other set of organs, yet it has been asserted,
hat we have not the same grounds for making a distinc-
tion between those of the pleura and those of the lungs
that practitioners of human medicine have. In man, it
i s said that this membrane is now and then the seat of
inflammation to the exclusion of concomitant disease
in the lungs, and that this affection, which has been
na.medpleujntis, may be known by the presence or preva-
lence of certain symptoms ; such as acute pain, generally
referred to but one side, which is increased by cough-
ing, or deep inspirations, accompanied with a pulse ^
frequent, small, and threaddy : though the latter, in-
deed, denotes membranous inflammation anywhere else.
So little dependance, however, is put in this diagnosis
by some of the most eminent physicians, that both pleu-
ritis and peripneumonia, or inflammation of the sub-
stance of the lungs, are commonly spoken of, and in-
deed are described by some under the name of pneu-
inmia ; by which is meant, an inflammation of the
mixed kind— one affecting both the lungs and their sur-
rounding membranes at the same time. . It seems to be
admitted then that genuine pleurisy is a rare disease
' even in the human subject, and I am ready to concede
thus much in regard to its presence in horses ; but I
must dissent from them who would deny its solitary ex-
istence altogether.

Not, however, that this observation is of much ser-
vice or importance to us in practice ; for, though I
am convinced from dissection of its truth, I do not pre-
tend to determine, during life, whether the case be one

268

Hijdrolliorax.

of pleurisy, or of peripneumony, or of pneumonia ;
though, by referring it to the latter, I should, perhaps
in nineteen cases out of twenty, find myself right in
my diagnosis. That more horses, however, that die of
acute thoracic disease, are cut off by pleurisy, and its
consequences, than by peripneumony, is known to evei y
practitioner ; but, then, in most of them the lungs par-
take more or less of the diseased action. Fortunately
for us, however, (as well as for surgeons,) after all, it
amounts to this — that there is no important or essential
difference in the treatment of the case, whether it be
one of pleurisy or peripneumony, or of both ; and for-
tunate indeed is it for the -dumb animal, inasmuch as two
of the characteristic symptoms consist in the particular
seat and kind of pain felt, about neither of which can
he give his medical attendant the least information*.

Hydrothorax. \

Hydrothorax, the common termination of pleurisy
in horses, consists in an unnatural collection of a

* " Perhaps my readers may be surprised at my not having given
some cases of pleurisy in this work, but I conceive it to be too nice
a distinction between this disease and an inflammation of the lungs,
for men who are not in the constant habit of the practice of physic, and.
that the most perceptible distinction worth attending to is, that the
horse is more frequently lying down and rising up suddenly, the in-
spirations are much shorter than in a local inflammation of the
lungs, the horse is very frequently turning his head back, and put-
ting his nose to the parts apparently most in pain, which to my
knowledge has frequently given rise to farriers and others to mis-
take an inflammation of the pleura and lungs for a spasm in the
intestines, commonly called the gripes. I have often found, in
cases of this nature, after horses have died with what is termed the
gripes, that there was a violent inflammation of ilte pleura, sometimes
•w\th hat slight iriflammation of the lungs, and Other parts." Shut's
Cases of FaiTicn/.

HydrothoraoH'. 269

atery fluid in one or both sides of the chest : the latter
use is the most frequent. In some few instances I have
nmd the fluid either confined to the anterior or poste-
lor part of the cavity by a transverse wall of adhesive
latter, or collected within a pouch or cyst of the
ame substance : this is what is denominated encysted
h opsy of the chest.

It was formerly thought that this (as well as all other
Iropsies of the body) originated in diminished absorption ;
)ut it is now believed to arise (I may say always) from
ncreased action on the part of the exhalents, the result
)f inflammation of the pleura : here then is one fact,
it least, to shew that this membrane is very prone
CO disease even in the horse. Very large quantities
jf water are occasionally effused in this way : I have
jften seen ten or twelve gallons measured from the
:hest after death ; but, from a troop horse that was
tapped for this disease in the Royal Horse Infirmary,
ixteen gallons were drawn ; a quantity that must be
considered prodigious, when we remember that some
still remains in the chest in all these cases, in conse-
cjuence of the apertures not being made through its
most dependant parts. In the generality of cases, the
Huid itself is transparent, of a bright yellow color, and in-
deed in its appearance and properties is similar to serum :
when it is found turbid, it is generally owing to the
ommixture of purulent matter.

The existence of this disease is often indicated, with
tolerable certainty, to the experienced veterinarian ; for,
though there is no single symptom that can be exclu-
sively relied on, still the presence of many, equally
characteristic, will furnish him in most cases with a
pretty correct though not infallible diagnosis. If an
inflammatory attack of the chest that has shown a

270 Hydrothorax.

painful activity, after having continued for two or
three weeks, or longer, abate, but not subside, and if it
be succeeded by such a train of symptoms as follows,
we may be pretty certain that the case has terminated
in hydrothorax, viz. the respiration, which had become
comparatively tranquil, shows fresh embarrassment,
and grows short and quick ; the pulse cannot be felt,
or but very indistinctly, at the heart, and is small,
weak, and frequent, and sometimes irregnilar, at the
jaw; and anasarcous swellings of the legs, breast, and
belly, and occasionally of the prepuce, make their ap-
pearance. As the animal continues to sink, which he
does, day by day, like a man in the last stage of phthi-
sis, his breathing becomes extremely irksome and pain-
ful, his head hangs low down under the manger, his
legs are wide extended to give full play to his chest,
he does not even notice his pi'ovender, and he moves
but with great unwillingness and effort. These last
mentioned symptoms however are but sympathetic ;
and of those which I have given as characteristic,
there is not one, by itself, that may not prove fallacious.
I have found water in the chest when the pulse has
been free and perceptible at the heart, when there has
been no anasarca, and when none of the tests I am
now going to make mention of, indicated its presence.
In some cases, by applying our head close to the side
of the chest, we may hear a gurgling or rattling noise,
occasioned by the undulations of the fluid during re-
spiration ; Mr. Shipp says, indeed, that he has felt it
"gush against the hand * and now and then, cer-

* " Upon pressing the hand upon the side of the breast, the water
may be felt to gush against the hand, but with more violence in the
act of expiration than during inspiration." Shipp's Cases of Farrier;/.

Hydrothorax. 27 1

rainly, indistinct fluctuations may be perceived, by ap-'
plying the hand, or the ear, against the ribs, while an
Assistant strikes smartly the opposite side : in this man-
ner percussion and auscultation may be made of great
ervice to us. Lastly, the stethoscope may be made
trial of.

. Our prognosis, when we suspect this disease to exist,
jmust be always very unfavorable. Some few untapped
ceases may have had a fortunate issue ; but of such we
Uiave no direct testimony. I have never seen a case,
tthat had undergone the operation, of recovery myself ;
Ibut I feel great pleasure in adding, that I am able to
ladduce two from indisputable authority.

The objects to be pursued in the treatment of hydro-
tthorax are twofold : first, we are to diminish any excess
oof action that may show itself in the sanguineous sys-
ttem, and thereby lessen the effusion of fluid into the
cchest ; and secondly, by increasing the action of the
aabsorbent system, effect the removal of what is already
»accuraulated. And fortunate would it be for our patient
iif these indications were as easily fulfilled, as in theoiy
tthey would appear to be. First, then, we are to inquire,
aand narrowly inquire, how far inflammatory action is
istill present, (of which the state of the respiration and
|)ulse are the leading symptoms,) and to take away blood
accordingly : from four to six pounds are generally suf-
ificient ; for large venesections in this stage of disease
invariably do harm. With the same view, we may ex-
ibibit small doses of white hellebore, which, by its nau-
weant effects, will tend most beneficially to lower the
ipulse and reduce its strength : in doses of a scruple,
repeated twice or thrice a day, it will be found to an-
iswer this purpose extremely well. I often conjoin it

272 Hydrotho7-ax.

with a proportion of calomel and some common turpen-
tine *, in order to augment the secretions of the chylo-
poietic and urinary organs at the same time. Blisters
frequently repeated to the sides, with the aid of rowels
and setons, are likely to do good by keeping up coun-
ter-irritation and discharge. I have, in several in-
stances, substituted corrosive sublimate for calomel
with apparent advantage, in consequence of its greater
activity ; ten grains of it twice a day, in conjunction
with hellebore and turpentine, is as good a medicine as
can be administered : nitre may be added if it be desir-
able to increase the diuretic effect. Purginor should be
avoided : aloes, unless it be given in laxative doses,
generally proves hurtful.

I have in several cases performed the operation of
paracentesis thoracis or tapping ; but in none with a
successful result. From an old horse I drew ten gal-
lons of water by means of a trocar made long for the
purpose, seven quarts from the left and thirty -three from
the right side of the chest ; he died on the fourth day
aftemards without having been apparently benefitted ;
after death, six gallons of fluid were found in the chest,
and about one quart in the cavity of the pericardium.
In another case, twelve quarts were drawn off from the
left side of the chest, and five days afterwards, as the
animal had not shown any relief, five more were taken
from the right ; by the last operation, the symptoms
appeared to have been aggravated instead of mitigated :
death ensued on the third day after it. On dissec-

* We generally make use of the following formula :
R Pulv. Rad. Veratri ; Hydr. Submur. sing. 9j.
Tereb. Vulg. 3ij.

Pulv. Glycyrrh. q. s. ut ft. Bol. — ter die sumendus.

Hydiotlurrax.

273

(ion of this subject, as occasionally happens when the
lisease has been of long duration, I found a quantity of
• LIS floating in, and partly mingled with the wAter,-
vhich now amounted in both sides to three gallons.

Though unsuccessfulness has attended my experi-
ments to preserve life in this manner, I have the
gratification to announce that two cures have been thus
performed under the skilful management of my friend,
Mr. Sewell ; by whom I have just been favored with
the subjoined accounts of them *.

* On the 16th of August, 1824, a bay horse, five years old, was
admittedinto the Veterinary College, who had fallen ill the previous
week with pneumonia, and had been bled and rowelled in the
chest, and had taken laxatives. At this time he was much wasted
in flesh, and so reduced that he faltered- in his step as he walked
to the stable. His respiration was oppressed and very quick, his
pulse 75°, and his other symptoms such as denote the presence
of hydrothorax. He was bled again, had aloes ^H. given to him,
was turned into a cool situation, had his legs flannel bandaged, and
was ordered to have a light diet. The day following, when the ear
was applied to one side of the chest and percussion to the other,
undulations were perceived, which were most distinct on the right
side. Having plunged a trocar into tlie left cavity, only an ounce;
of fluid was let out ; but from the right, which was afterwards pe-
netrated, four gallons of a serous fluid were drawn : this was fol-
lowed by much abatement of the pulse and respiration. 18th,
pulse 50o, respiration less oppressed, bowels open, appetite mended.
Tapped the left side again without effect. 19th, pulse 45°, respira-
tion tranquil. Tapped the right cavity and drew off two gallons.
Sumat Ferri Sulph. Jft. 22d, general amendment, pulse 40°.
The right cavity was tapped again, but this time without effect.
Rep. bol. 24th, coughs occasionally. 26th, pulse 38°. Omit,
bol. He gains flesh surprisingly fast. Nov. 7th, has lost his
cough, and bemg considered sufficiently recovered, is discharged
— cured. On the 7th of January following he experienced a
fresh attack of pneumonia at strawyard ; but there were no ac-
PART n. T

274

Hydrothorax,

For the performance of this operation the best instru-
ment is the common trocar ; it should however be one of
larger size than those in general use among surgeons :
the canula of the one I have, which answers the pur-
pose extremely well, measures four inches in length, and
5-sixteenths of an inch in diameter. As it is our object to
draw off as much of the fluid as we can by paracentesis,
the most dependant part of the chest should be pene-
trated ; at the same time, the operator must take care
that he does not pierce more parts than he is absolutely
compelled to do. Bearing these considerations in mind,
the preferable place for the introduction of the instrument
is the space between the eighth and ninth ribs, close to
their cartilages ; not between the latter, lest we punc-
ture the pericardium. Here, making the skin tense
with the fingers of the left hand, the instrument, with
its point directed upwards and inwards, may, with a
little rotatory movement, gradually be thrust in until re-
sistance to its entry suddenly ceases ; when the trocar
should be withdrawn, and the canula at the same time
pushed onward, lest it slip out. The water seldom flows
long in a continuous stream ; either the lungs come oc-
casionally in contact with the mouth of the canula, or

companying symptoms of efflision. He again recovered. After
this, he worked and continued in health for two years, and was
then sold.

Since this, Mr. Sewell has had another case of recovery from
hydrothorax. The horse was sold and taken into the country, and
there Mr. S. lost sight of him.

The above case shews the absolute necessity of tapping eurli/. It
is one that holds out flattering prospects to the skilful and zealous
practitioner; for, as he mu?t plainly see, the life of the horse thus
affected is entirely in his hands, and can only be saved by his pene
tration and prompt decision.

Adhesions.

275

loose flakes of adhesive matter collect about if; tb re-
move which we should, every now and then, introduce a
large whalebone probe through the pipe. Sometimes,
when the water is nearly run otF, air bubbles through the
pipe into the cavity : I never saw any harm arise from it ;
but, as it is only in the contraction of the chest that
water under such circumstances is pumped out, the in-
strument, probably, had better then be withdrawn.

I am convinced myself, that paracentesis has been so
unsuccessful from the irrecoverable state of the patients
on whom it has been employed : Mr. Sewell's cases, as
far as they go, are conclusive upon this point. When-
ever, therefore, symptoms make their appearance, in these
protracted pneumonic cases, that induce us even; to sus-
pect the presence of water, we ought to tap without de-
lay. The greatest evil that can arise from it, is puncture
of the lungs ; and from that I have not yet seen any ill
consequences, when the operation has been conducted
with that caution which characterises the scientific prac-
titioner. I am persuaded that some of my cases would
have been fortunate but for this delay ; and I feel little
hesitation in adding, that we shall soon have to record
aiany instances of recovery from hydrothorax, if veteri-
narians will but tiy to discriminate these cases, and will
institute early this bold but warrantable practice,
iii : 'fi 0;! '••■i'-i. •■ '-T^'T fJ,T n::';,.

Adhesions. \hr< Puox'ifvun

We seldom dissect a case of hydrothorax in which
we do not find more or less adhesion between the pleura
costalis and pleura pulmonalis ; in addition to which,
the membrane itself generally puts on a whitish or
opaque aspect in places, and is there thicker and firmer
than in the healthy condition.

T 2

276

Adhesions.

The horse is not near so liable to the formation of ad-
hesions as man ; for very seldom do the schools of human
anatomy obtain an adult subject for dissection in which
the thoracic viscera are perfectly healthy, and adhesions
are by far the most common morbid appearances that are
met with : it would appear, nevertheless that pneumonia
in hoi'ses, when it has been protracted, if it ends in death,
terminates more frequently in hydrothorax and adhe- ,
sions than in any other state of parts.

Little or no inconvenience seems to result from this
disease, during life, in the human subject ; for, though
the lungs are probably somewhat restrained in their mo-
tions, as those organs and the ribs are every where
closely applied to each other, and in common respiration
move together, they are not likely to be much interrupt- |
ed in their functions by a loose and partial connexion of •
their surfaces.

These adhesions consist of albuminous matter, and
are at first destitute of vascularity ; but, after a time,
they take on organization, and become converted into
membranous bands, whose texture resembles that of
condensed cellular membrane.

The formation of adhesions will take place in the>
course of a comparatively short space of time ; I have
known a horse to be attacked with pneumonia, and to;
die within the space of seventeen hours after ; in whom
numerous adhesions of the lungs to the ribs were found
on dissection. At this time, they consisted of yellow
shreds of albuminous matter, pregnant with serum, con-
necting the pleurse together, or hanging loosely from
their surfaces, easily totn through, and apparently
wholly inorganic : still, however, they constituted what
in anatomy we denominate adhesions. In consequence

Adhesions.

277

of the play of the lungs, adhesions soon become elon-
L;ated when once they are formed, giving to the interior
of the chest that cobweb-like appearance so familiar to
every one who has been in the habit of inspecting the
bodies of horses that have died of pleuritic disease.

When we reflect on the hasty strides that disease of
this nature makes in the horse, we shall find ample
reason to be exceedingly cautious in giving our opinion
as to the length of time that it may have existed, merely
from the presence, on dissection, of effused lymph or
water ; for I have, myself, strong reasons to believe,
from some unquestionable facts, that the one may be
deposited and form adhesions within the space of little
more than twelve hours, and that three gallons of water
may be poured out in the course of three days.

Pleurisy may terminate in empyema, or the effusion of
pus into the cavity. Now and then we perceive flakes of
pus, floating in the serous fluid collected in hydrotho-
rax ; but, should the matter be confined to one part by
adhesions, an abscess will form, which, if it be timely
discovered, may be discharged by an external opening^
Very lately, in a case of pleurisy that terminated in
liydrothorax, after death, I met with numerous, little,
red, rounded, membranous excrescences, growing from
the surface of the pleura pulmonalis in places, adhering
to it by short, thin, tjansparent productions of mem-
brane. I do not know that a similar case can be cited
in human pathology; they excited the curiosity of a
surgeon, a friend of mine, who was with me at the time
I made the discovery. I know nothing of their ori-
gin, and but little, as yet, of their nature : they are
very vascular, consist of doublings of membrane infold-
ing a little adipose matter, and arc continuous with the

278

Adhesions.

thin outer lamina of the pleura, with which they may be
stripped off without any apparent lesion of their roots.

In the human subject depositions of osseous matter
have been detected in the pleura. In the musemn at
St. Thomas' Hospital there is a beautiful specimen of
this change, which, it appeared, did not give rise to
any pleuritic symptoms during life : I am not aware
that a similar instance can be named in veterinary
practice.

LECTURE XXXVI.

On the Lungs.

The lungs or lights are two soft, spongy, compressi-
ble bodies, occupying the greater part of the cavity of
the chest.

They are the lateral parts, or sides of the cavity, that
these organs lie in ; where they are invested and confined
by their respective pleurae. Before the chest is bpened,
no space whatever exists between these organs and the
costal arches ; but, now, in the dead subject, they ap-
pear to be mtich too small for the' cavities allotted to
thettl. This arises from their being constantly inflated
dWfing life with atmospheric air, which preserves them
in a state of expansiofi ; as soon as the cavity is ttpelied
they suffer immediate collapse, and the c'on§eq<ience's
are, that the air is expelleid, and"th6y -theni'servies be-
come considerably ditninished in volunlife, -d BL^aa-', i^iit
' The lungs are two ih number— the rigfif aWl the left
lung, and are divided from [each other by the medi-
astinum. A further division of these organs has
been made into /o6es.— that On the right ' i^ld^; the

280 On the Lvngs.

larger of the two, consists of three lobes ; the left, only
of two : these lobes, which are nothing more than par-
tial divisions of the lung by fissures of variable extent
through its substance, serve to adapt them more accu-
rately to the cavities of the chest, and, at the same
time, render them fitter for the purposes of expansion
and contraction.

The lungs of the horse, when inflated, are of great
bulk * : the right is the larger of the two ; for, in con-
sequence of the heart being inclined to the left side of
the chest, in reality less space is given for the left lung.

The lungs are attached superiorly to the spine (which
attachment is sometimes called their roots) by blood-ves-
sels, the first divisions of the trachea, and the mediastinal
portions of the pleura ; every where else, in a healthy
subject, they are free and unconnected.

In form, the lungs of the horse are very like
those of the human subject ; and the latter have been
compared to the foot of an ox, to which the inject-
ed lung of the foetus bears indeed much resemblance ;
though the two lungs are not symmetrical, yet, both
together, they put on this shape, which is the counter-
part of that of the cavity they occupy. With regard to
their general figure, however, the lungs may be said to
be conical ; being broad and concave posteriorly, where
they are opposed to the convex surface of the diaphragm ;
narrow and somewhat pointed anteriorly, where they
are received into the blind pouches of the pleura, in
the space between the two first ribs.

In color, these organs are much variegated through-

* I consider, in comparison with the body, that they exceed in
magnitude those of the himian subject.

On the Lungs. 281

out their substance. Upon their surface they are of a
pale red, inclining to a pink hue, spotted in places
with purple and greyish patches ; no very accurate no-
tion, however, can be formed of their healthy aspect,
without repeated examination of them in horses re-
cently dead. If we cut into them, we shall find that
they are of a much darker hue than upon their surface,
owing chiefly to the blood they contain ; for, after
death, they generally possess more of this fluid than
during life, in consequence of its accumulating within
them in the act of dying.

On examination of the structure of these viscera, we
find that they are composed of the branches of arteries
and veins, and of the ramifications of the windpipe,
and that these vessels are connected together by an
abundant, intervening cellular substance, to which the
name oi parenchyma has been given. Beneath the curve
made within the chest by the posterior aorta, the tra-
chea divides into the two bronchiae, of which the right
is the larger, but the shorter : the left is the longer in
consequence of having to pass under the aorta in order
to reach the left lung. Having entered the substance of
the lung, the right bronchia divides into four others ;
the left only into three ; which difference arises from
;he right lung possessing an additional lobe; these
branches may be traced for a considerable way within
the parenchyma, giving oflT in their passage numerous
other smaller tubes of similar structure j but, as we
prosecute our dissection of them, we shall find that, in
growing smaller, they partake less and less of the na-
ture of cartilage, and that the extreme ramifications are
entirely membranous in their composition. It will be
• emembered here, that, in my lecture on the trachea.

282 On the Lungs.

I described ii membranous lining to it of the mucous
kind which, I said, thence passed into the bronchial
vessels ; now, it is of the continuation of this mem-
brane that the minute bronchise appear entirely to con-
sist ; at the extremity of every one of which it is
formed into a kind of blind bag or cul-de-sac, to which
the name of air-cell has been given.

From the arborescent ramification and peculiar modte
of termination of the bronchial tubes, some anatomists
have compared them, and the cells at their extremities,
to a bunch of grapes — supposing the stalks to represent
the ramifications of the bronchiae, and the grapes con-
nected with them the air-cells ; others have described
them as having a resemblance to a honey-comb : and so
far as the knife, with the aid of glasses, can develope
their intimate structure, the former is ah apt compari-
son, insomuch as it relates, to the disposition of their
cells ; the latter, insomuch as it conveys an idea of
their ready inter-communication. For, though the^
do not communicate but through the raiAifications <X
the bronchise, this is a medium of intercourse at oncfe
so general and free that numbers of them are inflated
at the same time by impelling air into any one of the
larger branches : with the parenchymatous substance
however they have no communication whatever.

The blood-vessels that enter into the composition of
the lungs are denominated the pulmorwri/ . The pul-
monary artery, having taken its oiigin from the right
ventricle of the heart, winds upward to the root of the
left lung, and there divides into the right and left pul-
monary arteries, which divisions enter their correspon-
dent lungs. The ramifications of these vessels accom-
pany tliose of the bronchiai, and like them divide and

On the Ltmgs. 283

lubdivide, grow smaller and augment in number as
hhey approach the air-cells ; upon the internal surfaces
<if which they terminate in extremely delicate, thin,
;nd transparent capillary tubes. Through these minute
eessels every particle of blood is impelled every time it
s circulated over the system; as I stated, when on the
Mood, a remarkable change of color is thereby effected
ui it, and we have now an opportunity of seeing in
Vhat manner this fluid is exposed to the influence of
fltmospheric air for the purpose. It is evident that no
ediate contact can happen between the air and the
ilood, for the thin, transparent side of the vessel, if not
at of the air-cell itself, must ever be interposed ; so
at whatever this influence be, it must take effect
rough these membranes. We might conceive indeed
at such minute vessels could not transmit through them
mch a body of fluid as the blood ; but when we look at
e volume of the lungs and consider the incalculable
lumber of air-cells they must contain, ' the globular
lUiface of eveiy one of which is furnished with a neit-
ork of pulmonary vessels, we shall feel more surprise
.d admiration at the extreme division and diffusion of
s fluid, in order to receive the necessary change, than
at such a prodigious number of capillaries should be
iqual, in their united calibre, to the pulmonary artery
if. «
r; From the extremities of the arteries, ; upon the &ur-
ace of the air-cell, begin the pulmonary veins. These
vessels, by repeated union with one another, form them-
;elves into visible branches, and these again into
'ranches of larger size, until, at length, they end in
our pulmonary venous trunks, which proceed to, and
erminate in, the left auricle of the heart. The ramifi-

284 On the Lutigs.

cations of these veins, unlike the generality of others,
are not more numerous than those of their correspon-
dent arteries ; and the reason of this is obvious ; for/
here, one set of vessels are not more subject to com^
pression than the other, nor does the heart (which is scf
proximate to them) require any such mechanical aidj
as an additional number of veins affords, to carry on
the circulation. The function of the pulmonary veins
is to convey the blood back to the heart, after it ha?
received its due change within the capillaries of the
air-cells.

Besides the above-mentioned blood-vessels, there are
two others, named the bro?ichial arteries. They come
off, by one trunk, from the posterior aorta, and each of
them enters a division of the lungs, in the substance of
which it branches forth and takes the course of the
bronchiae : they supply these tubes, as well as the^
coats of the pulmonary vessels and the parenchyma of
the lungs, with blood, in fact, they may be regarded
as the nutrient vessels of these organs. It has beefl
however, and still remains, a subject of dispute, whe-i
ther these vessels do %oholly nourish the substance of tb6
lungs, or not ; some say that they do ; while others assert-
that they are assisted in this function by the pulmo-
nary artery, with some of the branches of which they
anastomose. The latter opinion certainly does not ap-
pear to be supported by facts of much weight ; on the
contrary, the blood which the pulmonary arteries con-
tain is dark-colored, and unfit for the nutriment of any
organ ; and, as for anastomosis, we have no demon-
strative proof of its existence. The bronchial veins end
in one trunk which returns the blood into the vena azygds.

The nerves of the lungs are derived principally frorri

On the Lungs. "286

large plexus within the chest, constituted of the par

.gum and sympathetic : they enter in company with
le bronchial and pulmonary vessels, and continue
^leif course with those vessels to be dispersed upon the
ronchial membrane and parietes of the air-cells.

The absorbents of the lungs are large and numerous :
e may often succeed in injecting considerable numbers
t' them upon the surface, by introducing a quick-
ilver-pipe under the pleura pulmonalis.

The connecting: medium of the various constituent
arts of these organs, or, as it is termed, their ^amt-
/n/ma, appears to consist of little else- than cellular
issue, without any intertexture of adipose matter ; it
( Units of the free diffusion of any fluid that may be ex-

I avasated into it — of air that may have escaped from
he air-cells, or of serous fluid poured out when the lungs
re anasarcous ; but, as I said before, there is no inter-
oiirse between it and the cells or vessels, so long as
he organs preserve their integrity of structure.

The lungs, when healthy, are exceedingly light in
inparison to their volume ; so that if they be immersed

II water, unlike most other parts, they will float upon
he surface ; a fact familiar to every one who has seen
he liver and lights of an animal thrown into a pail of
Miter to be washed : indeed, the name of lights itself
^oems to have been given to them from this very pro-
lerty. If the foetal lungs, however, be so treated, they
>vill instantly sink to the bottom of the vessel; and

' his experimental result at once shews why those of

III animal that has once breathed should swim ; in the
le instance they contain air, in the other they are

A liolly free from it ; for, as I shall have occasion here-
after to explain, they are not to be regarded as respira-

286 On the Lungs.

tory organs in the foetus. It is evident, therefore, that
the lungs owe their property of Ughtness to the ait
they contain ; and, as a further proof of it, if that fluid
be by any means absorbed from them, and their bulk
diminished by collapse of the air-cells, like other vis-
cera, they will be heavier than an equal volum e of
water : hence it is that the lungs of a horse that has
died of hydrothorax, even though they are sound, are
of greater specific gravity than those of one in health.
It occasionally happens however, that these viscera
evince, in this particular, the properties of airless lung,
even though their natural volume and general appear-
ance remain the same : I take it, in this case, they
must be diseased.

'Thave already obsei-ved, that the lungs of the un-
opened thorax are in close apposition with its parietes,
but that they recede from the ribs and other parts as
soon as an aperture is made into the cavity. In order
to make perfectly intelligible the explanation of this
phenomenon, it is necessary to preface, that the lungs,
of themselves, have no power of action ; some degree
of elasticity resides in their parenchymatous substance,-
but, I repeat, they are of themselves altogether passive;
and as such are to be regarded in the functions of respi-'
ration. Their volume is augmented during inspiration,
from the distention of their cells with atmospheric air,
which rushes into them to fill the vacuum that would
othemise exist between the lungs and the parietes
of the chest ; it is diminished in expiration from the
expulsion of that air, by the compression they re-
ceive in the contraction of this cavity. But, observe
what happens if an opening be made into the cavity;
the chest, it is true, can dilate as before, but how, or by

On the Bronchial. Glands.

287

hat means, is the expansion of the lungs to be ef-
oted ? Not by the pressure of the atmosphere, for
-le weight of the air now upon their surface, which
as been let in through the artificial opening, is as
l eat as the expansive force of that within them, which
as passed down the windpipe and bronchial tubes :
•le pressure and counter-pressure therefore of the at-
losphere is now equal. Under these circumstances, the
mgs, being passive bodies, fall together by their own
lavity, or, as we technically express it, collapse and
lirink into a less volume than when they lie simply
uexpanded in the perfect chest.
If we take a bladder, inflate it, and lay it upon the
ible, without tying up its mouth, we know that the air
ill rapidly be expelled from it, in consequence of the
pper side gravitating upon that which lies in contact
ith the table ; and thus it is in the collapse of the
mgs ; the pressure and counter-pressure of the atmo-
|jhere being equal, their own gravity forces out most of
le air they may contain. But it appears that the lungs,
hen the chest is opened, suffer a more speedy and com -
lete collapse than what could be effected by gravity,
lone ; a fact that is rendered more striking by remov-
ig them from the body and inflating them, and one
lat we cannot very well account for, unless we ascribe
to (what indeed is now pretty generally acknow-
idged) elasticity, a property that probably more or less
ervades the several tissues entering into their compo-
ition.

On the Bronchial Glands.
These are small oval-shaped bodies, collected about
lie root of the windpipe, and trunks of the bronchiae.

288

On the Bronchial Glands.

just as they enter the substance of thel ungs. They
are of a dirty, French grey hue, interspersed with
dark bluish spots, and are about the size (though this
varies much) of a tick-bean. It was formerly supposed
that these glands secreted a peculiar fluid, which was
conveyed into the lungs, and imparted that remarkable
motley aspect to the parenchyma ; but it has of late*
been ascertained that they are nothing more than ab-
sorbent glands.

LECTURE XXXVII.

On the Physiology of the Lungs.

No subject in physiology more imperiously demands
lur attention and study, few subjects will better repay

- for the bestowment of our time and application, than
.his ; at the same time, I may add, none is more preg-
r.uit with speculative reasoning, and therefore requires
_reater caution, as well as discrimination in us, in the
idoption of our opinions.

The general functions of these organs are comprehend-

l in the term respiratmi ; and respiration may be said
io consist in the passage of air into and out of the lungs,
t hrough the channel of the windpipe ; or, as these al-
ternate acts have been expressed in single words, in
inspiration and expiration. Now, before we inquire for
what wise and important ends the process of respiration
was instituted in an animal body, it will be proper for
us to know how, or in what manner, its separate acts
inspiration and expiration are performed.

I have stated, (in a previous lecture,) that the parie-
' fs or walls of the chest are in part bony and in part

irtilaginous, and, I may add here, in part muscular ;

PA RT II, u

I

290 On the Physiology of the Lungs.

for not only are there, crossing the spaces between the
ribs, the intercostal muscles, but there are many others,
some of which are large and powerful, clothing the ex-
terior of the chest ; for the names and course of which
I must refer to the lectures on the muscles. The mus-
cles of the abdomen also I shall have occasion to ad-
vert to, as concerned in this function ; but, of all others,
none is so immediately interested in it as the diaphragm :
it behoves us therefore to make ourselves well acquaint-
ed with the composition, attachments, and action of
this last, in order that we may thoroughly understand
its operation, as the principal respiratory agent.

The first act of life, in the new-born animal, is one;
of inspiration. In the foetus, the cells of the lungs are
empty, and in a collapsed state ; but, as soon as birth
has taken place, respiration commences : the cells of
the lungs, then, become for the first time distended
with air by an act of inspiration, which, neither the
consequent expiration, nor any other subsequent effort,
ever completely expels from them ; so that these organs
in the foetus are, from their cells being entirely free
from air, of greater specific gravity than they are evey
found to be, while healthy, in animals that have once
respired. In what is called healthy or natural breathy
ing, probably no other muscular power is employed but
the diaphragm. This muscle, which we find to be aftei
death of a semispherical figure, is, when in action, re-
duced to a plane by receding towards the abdomen,
whereby the cavity of the chest is greatly augmented
in the longitudinal diameter : and this appears to be
all that happens in ordinary, moderate inspiration.
But in the human subject it is contended by some aur
thors, that the intercostal muscles contribute to thi^

On the Physiology of the Lungs. 291

ict. They are unquestionably muscles of inspiration, for
'hey have the power 'of enlarging the cavity of the
chest from side to side, by elevating the ribs, and, at
he same time, carrying their arches outward, and di-
ating the intercostal spaces ; were I however to ven-
tre an opinion on this subject, I should say, that
hey are seldom or never employed unless the inspira-
ions happen to be deeper or quicker than they are in
:ommon, tranquil breathing. And, with regard to the
lorse, I am still more disposed to doubt their action in
uidisturbed respiration — in a state of rest ; and particu-
arly as the chest of this animal, in his domesticated
late, is seldom free from the restraint of a girth or sur-
cingle, which must of course tend to prevent its dilata-
ion. Another set of inspiratory muscles are those that
)ass between the spine and ribs above, and between
he ribs and scapulae upon the sides ; all of which
lave more or less power, by abducting and separat-
ng the ribs, to dilate the thorax. But, it is only
n certain disturbed states of respiration that these
uxiharies are employed ; as, when the action of the
liaphragm is impeded, or inspiration becomes quick,
nd laborious, either from violent exertion, or from
lisease: if, for example, a horse, having distended
lowels, be galloped hard, or, as it is called, blown, he
rill instinctively employ these collateral powers ; on
leing pulled up, you will see him standing with his
ae legs directed outwards, in order that he may more
tfectually exert his serrati magni, by making his
lioulders fixed points, and abducting his scapulee as
'ich as possible from the ribs. Need I add, now that
. spine is fixed too, he will likewise employ his super-
II iales, transversales, and levatores costarum, as well

u 2

i

292 On the Physiology of the Lungs.

as his longissimi dorsi. And he will avail himself of the
action of these muscles with considerably greater ef-
fect, if the girths be slackened after exertion : a practi-
cal hint I need not give to those who are in the habit of
training. The same thing is evinced in horses laboring
under acute pneumonia : they rarely or never lie down;
in order that they may fix their spine and shoulders,
and withless difficulty expand their chest.

Expiration is rather the result of the cessation of ac-
tion in the afore-mentioned muscles, than one of mus-
cular agency itself ; though there are muscles of expi-
ration, as well as muscles of inspiration. Inspiration
being completed, a relaxation of those muscles that
have dilated the thorax ensues — I might perhaps have
said, to be consistent, of the diaphragm, which again:
resumes its convexity within the cavity of the thorax ^\
this is not however altogether a natural consequence oft
its own relaxation, but is in part the effect of contrac-:
tion in other muscles. In speaking of the diaphragm-
in action, I said that it receded towards the abdomen.'
Now, it is obvious that no retrocession can take place;
without some displacement of the viscera of that cavity;,
for they (like those of the thorax) completely fill it, and.
are therefore in contact at every point with the dia-
phragm. Being compressed, then, by the muscle dur-'-
ing its action, or rather protruded by it against the
abdominal muscles, these parts of the walls which are
soft and yielding, give way — admit of extension :
hence arises the swelling of the belly at every inspira-
tion, which, when evident to the common observer,
is vulgarly expressed by the phrase, " heaving of the
flanks." Thus far regards the act of inspiration ;
and now the action of the diaphragm having ceased.

On (he Physiology of the Lungs. 293

hat of expiration begins. The abdominal viscera, no
onger impressed by the diaphragm, cease to press
igainst the abdominal muscles, which, being now on the
>tretch, are already excited to contract, in order to
ecover from their extension : this they effect by gradu-
illy compressing the bowels, which find an easy return
nto the hollow of the chest, in consequence of the dia-
)hragm being relaxed and ready to resume its original
hape. If the ribs have been carried outward, and se-

.irated during inspiration by the intercostal or other
uuscles, they return, in expiration, to their places as

>on as those muscles have ceased to act, moved by
lieir own ligamentous connexions, but principally by
lieir cartilages, which, from being somewhat twisted
•y the abduction of the ribs, now re-act upon them by
irtue of elasticity. The working or heaving of the flanks
lien, so remarkable in quick or embarrassed breathing,
onsists in the alternate actions of the diaphragm and
ibdominal muscles: by attention to their motion, we
ire not only enabled to form an opinion of the healthy
tate of the lungs, but oftentimes to give a correct
liagnosis of the nature of pulmonary disease/

The lungs, though of themselves passive organs,

illow the motions of the chest, varying their volume
i nd figure so as to maintain a constant and close appo-
sition with its walls ; they are therefore expanded in
, ihe act of inspiration, contracted in that of expiration.
That organs should have motion which themselves pos-

ss no muscular power, may appear, at first view,
-oraewhat enigmatical ; the phenomenon, however, will
I'lmit of ready explanation as soon as we have consi-
Icred the circumstances under which they are placed.
In the first place, we know that the lungs are expansi-

294 On the Physiology of the Lungs.

ble bodies, and that they may be readily increased in
volume by inflation ; and secondly, we are aware that
they are everywhere in contact with the walls of the
thorax ; if, then, the cavity becomes enlarged, it follows
that, unless these bodies move too, there must be a
vacuum between them and its walls ; a state, we know,
that cannot possibly exist where the surrounding air
can exert the least influence;, at the same instant
therefore that the diaphragm recedes, air insensibly en-
ters the trachea and bronchial tubes, and expands the;
air-cells : indeed, were it not for this influx of air to
restore the equilibrium, the pressure of the atmosphere
upon the body would counteract the dilatation of the
chest altogether. Moreover, this influx of air is further
promoted by the rarefaction of that which is already
contained in their cells ; the effect of the communica-
tion of heat to it, and of some little expansion probably
of the cells themselves ; but the primum mobile is the
retrocession of the diaphragm and the consequent ten-
dency to produce a vacuuni. The fact of the collapse
of the lungs the moment the chest is penetrated,
may be mentioned here in elucidation of what I have
just stated : no sooner is air admitted into this cavity
than the pressure aad counterpressure of the atmosphere
are equal ; and therefore any expansion of them can no
longer be maintained *. During the expansion of the

* Though this is the common scholastic interpretation of these
phenomena, it has heen shaken of late by some experiments of
Dr. Williams', of Liverpool; who has shewn, that air admitted into
one side of the chest, or into both cavities of it simultaneously, (of
a dog) will not collapse the lungs, provided the animal is allowed un-
confined the use of his respiratory organs. He sayF, that one lung
possesses for a time, if inspiration be carried on by the other, iade-

On the Physiology of the Lungs. 295

ells, the pulmonary vessels are extended, and enlarged
II calibre, thereby affording a more free passage to the
blood ; a contrary effect ensues during their contraction,
for these vessels are then more or less compressed,
and perhaps contorted at the same time.

Respiration, though ordinarily an involuntary func-
tion, is at all times under the subjection of the will, so
that an animal may increase or diminish it at pleasure ;
and there are certain acts voluntarily performed by
means of it, which tend more or less to interrupt its
regular operations : such are coughing, neighing, snort-
ing, &c. Coughing consists in a sudden and violent ex-
piration, by which air is thrown with such rapidity and
force from the lungs and windpipe into the mouth as
to occasion that loud and familiar sound ; for, observe,
although in common respiration no air can pass into the
mouth, yet does it happen in coughing from the de-
pression of the larynx, which accompanies that act.
Neighing, which may be said to be the voice of the
horse, is a peculiar set of tones produced by a quick
accession of expirations, during which the sound be-
■omes variously modulated in its course through the
chambers and tortous passages of the nose. Snorting,
on the contrary, is a sonorous, protracted, and fearful
inspiration.

So far I have considered the physiology of these
organs in respect to what may be termed their mecha-
nical functions ; viz. the motions of the chest, and the
expansion and collapse of the air-cells, consequent

pendantly of the muscles of inspiration, a peculiar motive power,
the source of which he does not pretend to explain. Annals of Phi-

296 On the Physiology of the Lungs.

upon h e ingress and egress of air : I shall now take a
view of the chemical phenomena, as they have been
called ; under which may be classed the changes that
the blood undergoes during its pulmonary circulation,
and those that the respired air sustains in consequence
thereof.

When on the blood, I drew attention to the remark-
able difference of color that existed between that con-
tained in the pulmonary artery, and what circulated
through its corresponding veins, and I remarked that
this change took place in its course through the lungs ;
a change of such vital importance to the animal that
its omission but for a very short time will terminate ia
death. So intimate being the connexion between life
and respiration, it is not to be wondered at that physi-
ologists have, ever since the discovery of the circulation,
and more particularly of late years, zealously prosecuted
their investigations on this subject ; and though, with
the aid of chemistry, much useful knowlege has been
elicited by experiment and observation, still do we
(and probably ever shall) remain ignorant of what this
relation consists in. In order to pursue a regular
track in describing these phenomena, together with the
most plausible theories that have been offered, from time
to time, in explanation of them, it will be first neces-
sary to say a few words on the properties of common or
atmospheric air.

Chemists have demonstrated, that the air we breathe
is a compound body — that it consists of three airs or
gases, the names and proportions of which are as fol-
low : — twenty-seven parts of oxygen gas, or vital air,
seventy-two of nitrogen gas, and one of carbonic acid
gas. Of these, oxygen is by far the most important,

On the Physiology of the Lungs. 297

inasmuch as no animal can exist without its presence ;
so far indeed does its vital influence extend, that it is
m indispensable agent in vegetation : moreover, no in-
tiammable material can burn in its absence ; and hence
it has been emphatically styled " the supporter of com-
bustion," as well as of animal and vegetable life. Not-
withstanding its indispensability however for the sup-
port of life, no animal can live long in oxygen alone :
if you compel a dog to respire this gas in a state of pu-
rity, he will die from excessive stimulation of the system ;
though life will be presented longer by a given quantity
of oxygen than by an equal one of atmospheric air.
But, if the air be deprived of its oxygenous component,
either by combustion, or by prior respiration of it, it
will be found to.be incapable of supporting animal life,
or even further combustion. These facts are sufficient of
themselves to prove the indispensable service of oxy-
gen in the respiratory process.

Let us now inquire what demonstrable changes the
air undergoes in consequence of being respired. Nu-
merous and complicated have been the experiments,
vague and unsatisfactory the conclusions, that have
been handed down to us on this subject ; and it is only
since the commeiicement of the brilliant era of mo-
dern chemistry that physiologists have arrived at any
approximation to accuracy and truth. By a multi-
plicity of the most ingenious and conclusive expe-
riments, chemists have proved that the oxygen of the
air is diminished in quantity by respiration, though the
volumes of the inspired and expired airs are not mate-
rially altered ; they have also ascertained, with tolera-
ble precision, the quantity of oxygen consumed under
ordinary circumstances, during a given time, by a hu-

298 On the Physiology of the Lungs.

man being. It would be remote from the design of
these lectures to enter into a detail of the experiments
that have led to such conclusions ; let it suffice to re-
mark here, that about twenty-six or twenty-seven cubic
inches of that gas, at the temperature of 50" of Faren-
heit, have been found to be consumed by a man every
time he breathes ; and, if the quantity of air taken into
the lungs of a man at every inspiration were compared
with that inhaled by a horse, or any other animal, and
a reference made at the same time to the consumption
of oxygen by the former, estimates not very incorrect
might be formed probably of the consumption of vital
air by animals of various species and sizes. There are
certain difficulties attending this computation however,
even in the human subject ; for it has been ascertained,
that less oxygen is consumed at a high than at a low
temperature ; and that during digestion, or exercise, its
expenditure is something greater.

With respect to that constituent which makes up the
chief bulk of the atmosphere, the nitrogen, although it
will not support either combustion or animal life, yet it
is believed to be of itself perfectly innoxious when re-
spired. Indeed, it does not appear to receive any alter-
ation whatever from respiration ; for, if we examine the
expired air, we find that the nitrogen is in the same
state and quantity in which it existed previously to
having been breathed *.

Not so, however, with the remaining ingredient of
the air, the carbonic acid gas ; that always differs

* Dr. Edwards, of Paris, from some late experiments, believes
that nitrogen is both absorbed by the blood, and discharged from it,
during respiration.

On the Fhysiologif of the Lungs. 299

11 its relative proportions in common and respired
lirs, and is, if breathed alone, speedily fatal to ani-
mal life. If an animal be confined in a vessel filled
v\ ith this air, its life will be quickly extinguished ;
hough there are some writers who contend, that, if
iiis gas is of that kind which is formed by respiration,
t is not of itself deleterious, but proves destructive
jf life in consequence of the deficiency or total ab-
sence of oxygen. Whether this be strictly true or
not, carbonic acid is a product of respiration ; inas-
nuch as it is expelled, in a considerable quantity, from
the lungs at every expiration. From the most accurate
inalyses of the expired air of animals, it has been found,
that carbonic acid gas is produced in an equal propor-
tion to the oxygen that has disappeared ; so that if the
nitrogen remain unchanged and wholly unconsumed,
Juring respiration, and the formation of carbonic acid
be in pretty exact ratio to the loss of oxygen, it follows
that the volumes of the inspired and expired airs can-
not materially differ.

One great end that respiration appears to serve in the
animal economy, is the ejection of carbon or charcoal
from the system, through the medium of the lungs 5 to
what amount this takes place in so large an animal as
the horse, may probably be roughly estimated from
knowing, that in a common-sized man it is computed
that about eleven ounces of carbon are eliminated from
the blood in the course of twenty-four hours. With re-
ard to the consumption of oxygen, it is now generally
relieved, that what has disappeared of it, is wholly ex-
pended in the formation of carbonic acid gas, and that
none, no more than of the nitrogen, is absorbed by the
blood.

300 On lite PhijHiologi/ of the Lungs.

Let us now inquire if any, and what changes arc
jj reduced in the blood by respiration. I have already
had frequent occasion to notice the change of color as
one, and I would wish to regard this as only significant
of some other, and important alteration in the compo-
sition of that fluid, connected with the support of life ;
but, strange to say, our experimental chemists have
subjected both venous and arterial blood to the most
cautious analyses without having been able to detect
any difference whatever in their chemical composition.
I have stated, that no part of the air suffers diminution
in being breathed but the oxygen, and there is reason
to believe, from the known composition of the carbonic
acid which is formed, that the whole of it is expended
in the production of that gas ; consequently there can
be no absorption of oxygen, as was formerly supposed,
nor conversion of it into aqueous vapor, by combination
with hydrogen, emitted from the venous blood, as was
taught some few years back by the celebrated French
chemist, Lavoisier. For expired air always holds in
solution a proportion of aqueous vapor, which, in its
ordinary rarefied state, is imperceptible ; but, if from
any cause it is condensed, a steam in the breath be-
comes at once apparent : hence it is that we can see the
fumes of the breath on a frosty morning. In the hu-
man subject, many experiments have been made with a
view of ascertaining the quantity of aqueous vapor ex.
pired in a given time : the accounts, however, of dif-
ferent vvriters have been so veiy discordant and unsatis-
factory that I shall not hazard one here. Whether
this vapor be the product of evaporation of secretion,
from the surfaces of the air-cells and bronchial tubes, or
whether it flow at once from the mouths of exhalents.

On the Physiology of the Liargs. 301

remains doubtful : for my own part, I feel inclined
o side with them who maintain the first of these opi-
. lions *.

I shall now endeavour to shew, that the change of co-
lor is really the effect of the exposure of venous blood to
the influence of oxygen gas. One of the most familiar
proofs of it, is the well known difference which the ex-
posed and unexposed surfaces of a clot of blood in a
blood-basin exhibit : the former is of a bright red or scar-
let color ; the latter of a very dai'k modena red or black
hue. We have nothing more to do however, to effect
a change in these colors, than to invert the coagulum ;
in a short time, that which was black will acquire the
scarlet dye, while the under surface will slowly ex-

hanore its florid hue for the dark red or venous one.
But it is found even, that if a portion of blood contained
in a bladder be exposed to an air containing oxygen, a
similar effect will ensue, though the sides of the blad-
der intervene ; and if it be thus suspended in a vessel

if pure oxygen gas, the result will be still more striking.
But what heightens the interest of these experiments,
and makes them so conclusive and instructive to us, is
the newly discovered fact, that carbonic acid gas is actu-
ally formed or disengaged during the change. Here,
then, are experimental results closely bordering upon the
phenomena witnessed in respiration : for we are to re-
member, that the blood in its passage through the lungs

" " The surface from which the pulmonary exhalation is given
out, is equal, if not superior in extent, to that of the]skin; it is
thought that the quantity exhaled is as great. These two secretions
irc supplemental to one another ; when much water passes off by
the pulmonary exhalation, the cutaneous is less, and vice versa."

Ricueraud's Elements of Physiology.

302 On the Production of Animal Heat.

does not come into actual contact with the air, the pa-
rietes of the pulmonary vessels— if not the membrane
of the air-cells too, being interposed : like the blood
in tlie bladder, it evinces the influence of oxygen
through these transparent membranes, in taking on the
arterial character, and in liberating a quantity of car-
bonic acid gas. It has been and still is, indeed, a
subject of dispute, whether the carbon discharged
within the lungs is emitted through the sides of the pul-
monary capillaries, (which according to some are not
more than one-thousandth part of an inch in thick-
ness,) or whether it is an animal excretion, and as
such poured forth upon the membrane lining the air-
cells. This is far too nice a point for me to enter into
the discussion of, though I have thought it my duty to
make mention of it here, in order to complete this sum-
mary view I have taken of the principal phenomena of
respiration, and the theories in explanation of them which
I consider to be the best received at the present day.
It would be straying from my original design to prose-
cute this enticing investigation farther; I shall there-
fore take up the remainder of this lecture with the
consideration of a subject that has generally been
held to be inseparable from it.

0?i the Production of Animal Heat.

By animal heat is meant, that temperature which
animals possess and preserve above or below that of the
medium in which they live ; a temperature which, in
the superior classes, suffers but little variation under
every vicissitude of heat and cold, compatible with the
maintenance of life itself. This natural temperament
in man, is so constant, equable, and perpetual, says

On the Production of Animal Heat. 303

Blumenbach, that variety of constitution causes it to
iuctuate but little, even in the coldest climate, and
:nder the torrid zone. There are some species of ani-
uals whose natural temperature is so little above that of
:he medium in which they live — so inferior to that of the
ligher classes, that they have been distinguished as
old-blooded: of this nature are fish, and the various
ribes of reptiles and insects.

To Dr. Crawford are we indebted for a great va-
iety of facts which tend to prove that respiration is the
lOurce of animal heat ; an opinion, till lately, so uni-
brmly and generally received by the physiologists of
he day, that they have not hesitated to ascribe this
)peration to the lungs, as one of the most important
;nds connected with their economy. The explanation of
his process, according to the theory of that cele-
)rated physician, I now purpose to give in the abstract.

In the first place, we are to understand, that atmo-
spheric air, or the oxygen of it, (for that is the only part
ve have to do with here,) has in its composition a quan-
ity of caloric or absolute heat *, of a portion of which
he process of respiration deprives it. That this is the
:ase is satisfactorily proved by a nice examination of
common and respired air, as to their chemical compo-
sition, and the actual quantity of caloric that each is ca-
pable of containing ; therefore, in pursuance of this fact,
if it be proved that a part of the oxygen is appropriated,
in the manner I have described, to the formation of

* What is meant by caloric, is, that substance (regarding it as
material) to which matter owes its state of fluidity : water, for ex-
ample, only differs from ice, in containing more caloric, and steam
I rom water in possessing a still greater quantity of it.

304 On the Production of Animal Heat.

carbonic acid, it follows that heat must be liberated,
inasmuch as the capacity of the foi'mer for caloric ex-
ceeds that of an equal bulk of the latter ; so that we
may lay it down as a principle of this doctrine, that the
caloric contained in oxygen is diminished in quantity
by the change which that gas undergoes in the lungs.
Another proposition grounded upon the broad basis of'
direct experiment, is, that the blood contained in the
pulmonaiy veins and the left cavities of the heart, pos-
sesses more caloric than that in the pulmonaiy arteries
and right cavities of the heart ; in proof of which, if
equal quantities of arterial blood and water, and of ve-
nous blood and water, be mingled together, the tempe-
rature of the former mixture will exceed that of the
latter. An experiment related by Professor Coleman *,
tends very conclusively to establish this point. It con-
sisted in strangling a cat, and afterwards inflating the
lungs, so as to fill the pulmonary veins with florid blood,
and then in introducing a thermometer on either side of
the heart ; the temperature of the blood in the left side
was found to be two degrees lower than that in the right.
So far this would appear to impeach the result of the for-
mer experiment ; but, mark what follows ; " although,"
says the Professor, " the venous blood was superior ini
temperature at first, yet, before the coagulation was com-
plete, the arterial became from three to six degrees
warmer ; this, or nothing, aflfords a proof that heat is
received by the blood from breathing." These data,
once confirmed, scarcely need any remark to convincen
us, that caloric is absorbed by the blood during its

* "A Dissertation on Natural and Suspended 'Respiration." By
Edward Coleman." \

Oh the Production of Animal Heat. 305

mrse through the lungs ; and, if it can be shown,
mt the amount of caloric lost in the air is about equal
) the acquisition of it by the blood, surely we have no
uht to remain skeptical regarding thus much of the
ispiratory functions.

There are several phenomena however, relative to
Biimal heat, which it is incumbent on the supporters
ff this theory to explain before the question can be set
It rest : and here a very interesting question sug-
eests itself from the result of Professor Coleman's
sxperiment. How is it that the arterial blood, which
MS imbibed caloric from the airj instead of being aug-
aented in temperature, is diminished ? Dr. Craav-
(OBD explains this, by saying, that arterial blood has

larger capacity for caloric than venous, in conse-
laience of which it receives additional heat without
jecoming sensibly warmer ; on the contrary, as we have
iist seen, it is two deo-rees colder than before it w^as
Kposed to the air, from having been diffused over the
ar-cells of the lungs, and there exposed to a dimi-
ished temperature. Another fact, not less deserving
T our attention, is, that when an animal is placed in a
;iarm medium, the consumption of oxygen is less than
l-hen it is exposed to a cold one, and that if blood be
itiwn from the veins under these circumstances, it will
!e found to possess the arterial character : how is this
»int to be cleared up ? It is reasonable to expect (ac-
ording to this ingenious theorist) that the expenditure
F heat in an animal cannot be so sreat when sur-
ounded by a warm atmosphere as when placed in a
bid one ; its demand therefore for caloric in the lungs,
au8t be proportion ably less ; and thus, the smaller
onsumption of vital air, or, in other words, the dimi-

PAK'I II. X

306

On the Pro(hiclio7i of Animal Heal .

nished absorption of caloric is accounted for. But
with regard to those animals that live in a cold atmo-
sphere, the converse of this will, of course, take place ;
not, however, that it is necessary for them to breathe
quicker under such circumstances, or even to take in
larger quantities of air, as some have imagined ; for if
is found by experiment, that the whole quantity of
oxygen taken in at any single inspiration is never coi^^
sumed : only so much of it disappears as is require^
for the immediate purposes of the animal economy.
Independently of this consideration, however, more aif
is actually inhaled, consequently more oxygen, in col
than in warm weather ; for if equal volumes of co'
and heated air be weighed, the former will be found to
be specifically heavier than the latter : a proof that thft
supply itself of heat is greater at a low than at a higbi
temperature. .A
Having detailed some of the principal facts connectflw
with the production of animal heat, let me now curiK^S
rily point out the mode in which the process is sug*^
posed to be carried on. Blood, charged with carbon,
which it has received in its circulation over the body,
having entered the capillaries of the lungs, and there
being exposed to the influence of atmospheric air, dis»
burthens itself of this matter, which flies off in the
breath in the form of carbonic acid gas, by combining,
for that purpose, with a sufficiency of oxygen. Now,
it is the discharge of carbon that prepares the blood
with a fresh capacity for caloric, and it is the union of
this carbon with oxygen that, at the same instant, causes
the evolution of caloric, in consequence of the capacity
of carbonic acid gas being inferior to that of oxy-
genous ; the production of heat therefore, and the ca-

On the Production of Animal Heat. 307

iiicity of the blood to receive and retain it, are conse-
]iient and almost simultaneous operations : and upon
iiese two phenomena it is, according to our present
theory, that depends the generation of animal heat.

Caloric, thus supplied, is evolved, as sensible heat,
luring the circulation of the blood to every part of the ^
)ody. Dr. Crawford imagined, that it was only
2,1 ven out in ihe capillaries ; but subsequent experi-
iients render it highly probable that it is also liberated
u the trunks. Thus it is, then, that an animal is
viirmed ; thus it is, that he is enabled to preserve a de-
rree of heat superior to that of the inanimate matter
round him. But, though caloric is also disengaged
a the larger blood-vessels, it is in the capillaries that its
liffusion is greatest, inasmuch as in them the blood is
xposed to a comparatively larger surface of solid ; it is,
onsequently, in the latter more especially that the blood
mdergoes the change from the arterial to the venous
haracter, and loses its capacity for caloric in propor-
lon as it grows dark and viscid from the absorption of
arbon. In this way then, a heat, varying somewhat in
ts degree in the higher order of animals, is maintained
'1 all of them : in man it rarely exceeds 98 °. in a state of
lealth, but is frequently much lower in the exterior

irts ; but in quadrupeds, in the interior of the body,
lie thermometer will rise one or two degrees above
00°. of Farenheit ; and in birds, not unfrequently six
'r even eight. i ,

By some curious and very interesting experiments,
t has been proved that a human being can survive, and
ven endure for a certain time with impunity, an atmo-
phere heated to a degree much superior to that of the
)ody itself. Dr. Fokdyce, Sir Joseph Banks, artd

X 2

308 On the Production of' Animal Heat.

some other gentlemen, had chambers so constructed
that they could heat them to a very high temperature ;
and, after havmg tried successive augmentations, at
length entered one heated to the excessive pitch of
260". and remained in it for a time without experienc-
ing much inconvenience, although they were naked
during some part of the experiment. The heat was so
intense that they were afraid to touch the metallic
buttons upon their coats ; and both eggs and beef-
steaks were dressed in the course of their venturesome
exposures. Now, under these circumstances, I)t,
Crawford states, that the lungs, instead of furnish-
ing the animal with heat, become a medium by which;
his body is kept cool ; an operation the doctor explains
by saying, that the evaporation from their internal sur-
face will carry off the excess of artificial heat, and-
leave the arterial blood actually much cooler in its re-i
turn to the left side of the heart : so that in truth, now,
the blood, instead of imparting heat to the different
organs of the body, will absorb it from them, during
its circulation.

Though Dr. Crawford appears satisfactorily to
have unravelled the principal phenomena of respiration,
still it is probable, from some interesting expenments
lately published by Mr. Brodie, that we have much
to learn in regard to the generation of animal heat.
By decapitating animals, so as to destroy all communi-
cation between the brain and the lungs, Mr. B. has
found, although respiration can be so performed artifi-
cially that the usual chemical changes take place in the
blood during its course through the lungs, that the heat
of the animal gradually diminishes, and even more ra-
pidly than if no such artificial process were carried on :

On the Production of Animal Heat. 309

a circumstance he refers to a succession of blasts of
cool air being thrown into the lungs. From which fact,
substantiated by a repetition of experiments, Mr.
Brodie is of opinion, that we should rather attribute
animal heat to the nei-vous energy than to any chemical
alteration in the properties of the blood. The respira-
toi-y function, itself under the influence of vitality, is
certainly requisite to the production of animal heat ;
but the evolution of it appears to be the result of ner-
vous energy, imparted to the blood, through the medium
of the vessels through which it circulates.

LECTURE XXXVIII.

On the Diseases of the Lungs.

The most destructive and insidious diseases to which
both men and horses are obnoxious in this cUmate, are
those that originate within the cavity of the chest. Of
the two principal organs contained therein, the one, by
its propulsive power, circulates the blood ; the other
forms an animal elaboratory, where certain chemical and
vital changes are wrought in that fluid, to render it fit
for the several purposes for which it is distributed over
the system. The diseases of the latter, to which I es-
pecially allude here, form a subject of intense and pe-
culiar interest to the veterinarian ; for, regarding the
horse as the slave of man, if his wind be organically
impaired, he is useless to his possessor : he may be
blind, lame, farcied, and even glandered, and yet con-
tinue, in some measure, serviceable ; but no sooner has-
his respiration become constitutionally embaiTassed than
he is found to be incapable of undergoing further labor,
in which state he either lingers out a painful existence,
or ends his days, a wretched spectacle, within the walls
of a slaughter-house. Prior to entering on the consider-

On the Diseases of the Lungs. 311

ation of the various forms in which these maladies pre-
sent themselves, • I shall inquire under what circum-
stances pulmonary disease in general is generated ; and
how we may best preserve the animal, in his domestic
state, from its insidious and dangerous attack.

Horses, before they are stabled and broken, are sel-
dom or never affected with disease. No quadruped,
within our domestic circle, enjoys sounder health, none
by his natural habits tends to preserve it more, and
none has stronger restorative powers than the horse ;
when taken from his native fields, however, as no beast
is so kindly treated and so abused by man, so no one
is equally subject to disease in all its various forms,
but, above all, to disease of the lungs. Keeping this
plain but important truth in view, let us inquire what
are the obvious changes in the circumstances and ha-
bits of life of this animal, when caught up from the
field and housed for the first time. Temperature pre-
sents itself as the primary one : there are but few days
in the year in this climate, in which the temperature of
an ordinary stable does not exceed that of the external
air ; and the colder the season is of course the greater
is the contrast between them. Food makes another im-
portant change of condition : instead of the green herb
of the field, with such occasional variety as his haunts
might have furnished him with, art now culls for him
provender, the best of its kind, and either spreads it be-
fore him in luxurious profusion, or sparingly supplies
him with barely suflBicient for his sustenance ; the kind
of food, perhaps, is less worthy of notice than the mode
in which it is given to an animal that until lately has
helped himself ad libitum from the salubrious herb and

312 On the Diseases of the Luugs.

pure spring of the forest. Exercise, which the colt has
been used to take unconsciously, as it were, in his
quest after food, is now given according to the conve-
nience or caprice of his master, in a mode and degree
probably alike deviating from what is natural to him.
Lastly, the horse exchanges the pure atmosphere of the
open field for the tainted one of the stable ; and though
no animal naturally more abhors the stench of his own
excretions, nor can with more acuteness perceive their
pestiferous effluvia, yet is there not one that we have
domesticated that we compel to live in more noisome
situations.

To one or other of these changes of condition may be
referred the causes of disease in horses : not to dive
into the depths, however, of this general investiga-
tion of them, which would lead us from our present
object, I shall proceed at once to point out what the
exciting causes are of diseases of the lungs. Seeing
that, in a state of nature, the animal is not the subject
of pulmonary disease, we cannot attribute it to any in-
dividual agent to which he is then equally, if not more
exposed : if, for example, cold * produced it, pneumo-
nia ought to be more prevalent at this time ; so, also,
by parity of reasoning, we may argue that it is not
heat, for many horses in hot climates are exposed to a
higher degree of heat in their natural than in their do-
mestic state. Alternations of these conditions, however,
appear to be powerfully influential in the production
of this disease ; a fact indeed which a knowledge of the

* The word cold is used here to express a comparative low degree
of heat : in this view, I would regard cold and heat as distinct agents;
it will save periphrasis as we proceed.

On the Diseases of the Lungs. 313

physiology of the lungs may lead us to understand,
since no part of the animal is so much under the opera-
tion of changes of temperature as the mucous mem-
brane lining the nose, windpipe, and air-cells, with
which cold or heated air must actually come in contact
at every inspiration, in a manner I have before pointed
out. If we couple this physiological truth, then, with
the exciting cause of inflammation in general, need we
feel surprised when we find that this membrane, of all
other parts, suffers from the operation of such agents ? —
that, in other words, it is so disposed to take on inflam-
matory action every time an animal is taken from a
cold to a hot atmosphere ? Were this fact not too long
established in practice to render many, by way of proof,
necessary here, instances enough might be brought for-
ward, both in the human subject and in horses, to illus-
trate and confirm it : — soldiers during a campaign in
the cold season of the year, to which they have turned
out from long-accustomed, warm, and comfortable
quarters, never experience any thing like the illness
(and seldom any of a pulmonary nature) they do on
re-entering into barracks ; and as for horses that are
similarly exposed, after having been pampered up' in
excellent stables, they contract hardly any disease
until they are once more warmly stalled. What men
are commonly the subjects af pneumonic affections ?
.Not those who are much exposed, and badly housed,
but such as inhabit comfortable dwellings, and are well
clothed and fed : so it is with horses ; we do not often
see pneumonia in agricultural horses ; seldom or never
-in such as live on commons, or iri open yards ; but in
gentlemen's studs, hunters, racers, and coach and post
'horses, nothing is more common than catarrhal and

314 On the Diseases of the Lungs.

pulmonic attacks. You are not to imagine, however,
that either a man or a horse can be taken from a very
warm situation and suddenly placed in an intensely
cold one with impunity, any more than, because you
have an infallible remedy for a disease, you can give
any quantity of it without injury ; for, though sudden
changes from cold to heat are prejudicial, heat of itself
is not more injurious than cold, and were not the ani-
mal previously exposed to cold no evil would arise from
his subsequent exposure to heat : in this light, cold is
sometimes viewed as the predisposing cause of inflamma-
tion. '

With respect to the change of food, there cannot be
a doubt but it must dispose, from its being the chief
cause of plethora, to general diathesis of system ; and,
so far, it contributes to the production of pneumonia,
or any other inflammatory affection. Horses that are
well fed, and but little worked, are frequently the sub-
jects of this disease ; and, though some may assert
that this is wholly attributable to the nature of the at-
mosphere they breathe, I must still contend, that pam-
pered horses, like robust men, are, casteris paribus, more
liable than others to inflammations of every kind.

Exercise, at least, laborious and unprepared-for ex-
ertion, is another and an obvious source to which we
may trace this disease. There is none of us who has
not witnessed attacks of pneumonia from hard riding,
or hard driving : in fact, in the hunting season the oc-
currence is a very common one.

Lastly, can an atmosphere, of a mean temperature,
contaminated with the animal effluvia generated in the
decomposition of the excretions, and the carbonic acid
gas cast off with the expired air, be considered of itself

On the Diseases of the Lungs. 315

I as an excitant of pneumonia ? Now, as heat is a pretty

< constant constituent of such an atmosphere, it appears,
I ait first view, difficult to say, whether it be to one or the

< other that we should ascribe the excitation of disease :
I from numerous facts and obsei-vations, however, col-
I lected by practitioners who have paid attention to this

subject, with many of whom I have held converse, I
feel inclined to believe, that pneumonia is rather the
product of heat than of animal poison. There have been
situations occupied by great numbers of horses in which
these poisonous agents may be said to have been present
without the co-operation of heat ; and where, though the
prevalence of other diseases sufficiently evinced their
morbid influence, pneumonia was hardly ever seen. In
averring thus much, I allude more particularly to what
happened in the practice of the veterinary surgeons (of
whom I was myself one) who did duty with the army
in the Peninsula. Both in Portugal and Spain, most
of the stables, or places used as stables, were dirty and
filthy in the extreme, being either without any pave-
ment at all, or so badly paved that there were no sewers
to drain off the urine. In these situations, both horses
and mules, of which the number was considerable,
during the march, contracted farcy, glanders, and
mange ; but very few of them, inflammation of the
lungs, and simply, I believe, for this reason — that tlie
stables, though unwholesome from being so foul, were
cold, either from their size, or from dilapidations, and
consequently did not subject the animals to severe and
sudden changes of temperature. Another argument,
that just occurs to me, against the opinion that pneu-
monia mostly originates from breathing a polluted at-
mosphere, is this— that it is, in itself, a malady free

316 On the Diseases of ' the Lungs.

from any malignant character ; whereas the diseases,
generally speaking, that are generated by such agents,
exhibit more or less malignancy in their nature : such
are glanders and farcy ; and, in the human subject,
typhoid, gaol, and putrid fevers.

Concluding then that heat and unprepared-for exertion
more especially act as the exciting causes of pneumonia,
it does not require much penetration to discover by what
means we can best protect the animal from its invasion.
Of late years, with this view. Professor Coleman has
recommended the stables of the several cavalry bar-
racks in Great Britain to be ventilated. With one part
of the principle no man who has ever understood the
subject can be at variance ; if alternations of cold and
heat be the cause, that which tends to lessen the seve-
rity of these changes must be, in the degree in which
it does so, the preventive ; and if this be the object, I
consider it is as an undeniable one ; but if it extend to
the purijication of the atmosphere, from what I have
stated before, I think that its salutary influence, so far
as reg&rds pneumonia, is highly questionable*. Ven-

* By the bye, tliere is a fault that has been committed in all the
cavalry stables that I have seen by those who have put Mr. Cole-
man's plans in execution, vk^hich it will be as well to avoid in future.
The upper vent holes, which are for the purpose of giving exit to heat-
ed air, are made by taking out one or more of the bricks nearest to
the ceiling or roof, over the horse's head, and are consequently horizon-
tal. Now, for ventilation, the best direction for the aperture is the
vertical, seeing that air when rarefied is always carried upward; but
this is objectionable from its admitting wet, &c. upon the horse ; I
therefore recommend that the aperture be made oblique, which still
gives free vent to the current of heated air, and at the same time
shelters the stable both from wet and wind : for I n\ay remark that,
in some stables, the liorizonlal opening gives passage to a current of

On the Diseases of the Lungs. 317

tilation then is one mode, and one in which consists the
grand secret of keeping horses healthy ; for, although
we may not agree as to the modus operandi, or mode in
which a temperate and pure atmosphere preserves
. health, we shall all concm- in opinion regarding the
I fact, that this, and this alone, is the chief preventive
of disease. He that has clean and cool stables, will
have a healthy stud ; and the converse of this will
never fail to engender disease. Above all other consi-
derations then, in taking the colt from his natural state,
it behoves us to guard him from the vicissitudes of cold
'and heat, and to keep him in an atmosphere as pure as
that of which we have just deprived him. Wliy is it
that so many young horses die during the autumnal
and spring seasons of the year ? Or why do so many,
after they have left the breeder's possession, fall victims
to pulmonary disease in the dealers' stables of the me-
tropolis ? — or why have such numbers been lost to the
cavalry, whose stables formerly were very badly con-
structed ? I am aware that it may be said, and with
great truth, in answer to the first of these questions,
that horses at these fatal seasons are changing their
coats, and that they are naturally weaker, and more
likely to prove unhealthy, and that food, exercise,
and a foul atmosphere are also operant in the produc-
tion of disease ; admitting all this, however, I still
maintain that heat, or at least the sudden change
from cold to heat, is the chief pernicious agent.
Horses of any age, but above all young horses, should
never be exposed to a heated air : they may be warmly

cold air from without, instead of escape to the heated air from
within.

318 On the Diseases of the Lungs.

clothed, and even with advantage kept in moderately
warm stables, but they ought never to respire a hot and
stimulating atmosphere.

The next circumstance to be attended to in order to
preserve the health of a horse recently domesticated, is
exercise. Compelling this animal at once to perform
such exercise as comes under the denomination of
7D07-k, is surely subjecting him to the invasion of disease,
and of disease, most probably, of his organs of respira-
tion : hence the old observation, " a young horse
never ought to be sweated in his exercise." Numberless
horses, not only young ones, but of all ages, are from*
want of consideration on the part of their owners, killed
in this way in the course of the year. A person purchases
a young horse of a dealer, who most likely has had
him for some weeks, during which time the animal has
been getting yresA, as the dealer calls it — i.e. he has
been pampered with all possible care, fed as if he were
put up to be fattened for the butcher, and little, or not
at all, exercised : suddenly the horse, by way of trials
is made to perform, by his new master, what he calls,-
and to another would have been, but moderate work,
but what to this is excessive exertion, and the con-
sequence is, that the animal is attacked with pneu-
monia, and dies in the course of eight and forty
hours. It is of the utmost consequence therefore to
attend to this circumstance ; if the horse be young, we
cannot be too gentle with him in regard to liis exercise,
for at this period he is totally unfit for work. For the
first week, he should be walked out for an hour every
morning ; during the second week, this may be repeated
in the afternoon ; and during the third, the time of ex-
ercise may be prolonged to an hour and a half or two

On the Diseasea of the Lungs. 319

hours. At the expiration of a month, he may be
trotted ; and this pace should be entered upon slowly and
increased with the same caution as his walking exercise
has been : but care should be taken even yet not to
make him sweat. Though a horse newly purchased of
a dealer is one whose age indicates that he is able
to work, still, in consequence of his having probably
been kept long in a state of inactivity, will some such
regimen be required to put him even in actual con-
dition for hard work : hunting a horse with others
under such circumstances, is like matching a man
nursed in the lap of indolence to contend with a pugilist
in hard and continual training.

Food, though a secondary measure, is one that is
not to be entirely disregarded. If the horse be young,
and but lately brought into the stable, or recently pur-
chased from the breeder, his food ought to be of that
kind which is easy of digestion, and, at the same time,
not too nutritious : it is far better to feed him partly on
bran and hay chaff* than to supply him with a full
allowance of corn ; you may give him half-a-peck of
oats, mixed with twice that quantity of bran or chaff,
in four feeds, in the course of the day ; the object
being to prevent any approach to plethora from high-
feeding. After a time, the proportion of corn may be
augmented, and the bran and chaff gradually with-
drawn ; until, at length, he may be allowed three or
four feeds of corn, or oats and beans, in the course of
the day, as his exercise becomes more laborious, and
his condition appears to require it.

* Hay chaff should be cut from the best sainfoin, lucerne, or
clover.

320

InJiammatio7i of the Lungs.

Inflammation of the substance of the lungs,
technically called peripneumom/ , at the same time that
it is one of the most destructive in the catalogue of vete-
rinary diseases, is one of almost daily occurrence; it is
therefore a duty incumbent upon us to make ourselves
well acquainted with all that is known respecting it.

Its attack is often so sudden that it gains consider-
able violence before the horse is even suspected to be
unwell ; but in other cases it will be preceded by re-
gular febrile symptoms. A shivering fit, succeeded by
a transitory heat of skin, and dryness of the mouth,
though the extreme parts of the body generally maintain
their coldness, is a very common precursor, accompa-
nied with dulness, loss of appetite, and accelerated pulse.
At length, the respiration becomes short, quick, and
painful ; not exactly such as is symptomatic of common
irritative fever, nor such, as is characteristic of broken
wind or thick wind : in acute pneumonia the flanks
work with great celerity. I have often known the respira-
tion to exceed the pulse in frequency, and every heave
is manifestly attended with exertion and pain ; at the
same time, there is a degree of regularity in the work-
ing of the flanks that marks the presence of inflamma-
toiy action. The pulse also runs on vfith great quick-
ness— 90° or 100°, but is commonly not remarkable for
strength ; indeed, in many cases, it is the reverse, and
in some is indistinct or altogether imperceptible at the
heart. The animal soon grows chilly again, his coat
stares, and his ears and legs have an icy coldness.
He stands with his -fore-legs stiffened and stretched
out, his neck extended, his nose protruded, every now

lnj)ammatioii of the Lungs. 321

and then turning his head round to his side, working
and puffing with his expanded nostrils at every labori-
ous and painful heave he makes. His countenance- —
his eye, to the observant practitioner the index of his
sufferings, bears visible signs of distress, and makes an
impressive though silent appeal to us for relief. He
never lies down for rest — even at night. Cough is
rarely present *.

Should the breathing, after an elapse of about twelve,
or from twelve to twenty -four hours, become oppres-
sive, the pulse upward of 100". and feeble, or* grow
andistinct or altogether imperceptible, both at the jaw
rand heart, the skin remain cold, or be bedewed
>with a clammy sweat, the mouth have an icy cadave-
t rous feel, and the animal, in a paroxysm of pain, often
Hie down and momentarily rise again, we may conclude
t that the case is a hopeless one : if blood be drawn at
t this period, it will exhibit the darkest venous (nearly
tblack) hue, be thick and viscid, and flow with much
ttardiness from the vfein, forming clots upon the hair
( or side of the blood-pan as it slowly trickles down the
rrieck.

' By the accounts that have been given of this disease
tin horses, I am led to believe that it has not been viewed
(■in its pro]Der light ; for we are to remember that, in these
rcases, it is the bronchial — the nutritive vessels of the
oofgans that are primarily affected, and that the pul-

,* It may be a matter of surprise ;that peripncumony, which is
inot of itself a very painful disease in a , man, should be described
tas so distressing in a horse ; but, the' fact is, that, to speak cor-
trectly, it is pneumonia, and not abstract pcripneumony, that is
rfiBrc pourtrayed. . 't knoW ' of no difference myself- iii, the sympto-
nnitology of pleurisy and peripneumony

PART II. Y

322 Inflammation of the Jjimgs.

monary are only secondarily so. In hepatitis, though
the functions of the vena portse are disturbed, it is the
hepatic artery that is primarily and principally en-
gaged in the inflammation ; and, for similar reasons,
the bronchial and not the pulmonary, are the supporters
of inflammation in peripneumony. Bearing this in
mind, the different phenomena of the disease will ad-
mit of satisfactory developement. The respiration is
short and quick at first in consequence of the tumor
and preternatural irritability attendant on inflammation
in this, as in any other part of the body ; the tumefied
and infiltrated parenchyma compresses the smaller
bronchiffi and the air-cells, so that not so much air can
be admitted at each inspiration as in health ; and from
the same cause that the air-tubes and air-cells are
compressed, the pulmonary vessels are also diminished
in calibre, and the blood which, from their partaking
of the pulmonary excitement, is now determined to
them also in undue quantities, finds its passage with
difficulty through them ; the consequences of this are^
engorgement of the lungs themselves, but small,
though frequent supplies of blood to the left side of th^
heart, and that not duly oxygenized ; to which, and
to the sympathetic irritability of the heart itself^ we
may ascribe the frequency of the pulse, and the ab-
sence of strength in it. But the right side of the heart,
on the contraiy, has too much blood, resulting fi:om
this pulmonary obstruction, and this is the source of that 'i
pulse which is called the oppressed, as well as of its l|
occasional irregularity, in which condition the action i J
of the heart is feeble from over-distention : hence it is II
that the pulse, at first weak or imperceptible, so, often ■
acquires freedom and strength from a well-timed vene- I

Injiammatiou of the Lungs. 323

section. The skin is cold for three reasons : — first,
because the left side of the heart, not having its ordi-
nary supply of blood, cannot propel the requisite quan-
tum to the extreme parts of the body; secondly, be-
cause the blood itself has not undergone the full degree
of change — hence also the livid hue of the membrane
of the mouth ; and thirdly, because so much more
blood than in health is carried by the pulmonary as
well as the bronchial arteries into the lungs, in the
substance of which it is so much longer detained.
The horse extends his fore legs outward in stand-
ing, and refrains from lying down, in order that he may,
with all possible effect, exert hrs serrati magni, and
other muscles running from the shoulder and spine to
the ribs ; he straightens his neck, protrudes his nose,
and dilates his nostrils, that he may facilitate the
. egress and ingress of airi

I have already said so much about the exciting
I causes of pulmonic disease, that it cannot be necessary
I but to name them here. From exposure to cold the
■ sudden vicissitude of heat, ranks pre-eminently above
. any other ; over-exertion stands next in the list ; some-
1 times the disease appears to arise spontaneously.

Pulmonary disease runs its course now . and then
with surprising rapidity. I have known a horse to
1 be attacked with acute pneumonia, and to die from it in
I the space of seventeen hours, and it is by no means
' uncommon for it to prove fatal on the second or third
< day from its onset. Ignorance of this fact has led to
' the institution of many law-suits, and to some oppres-
• sive judicial arbitrations for horse-dealers : e.g. a-
gentleman purchases a young horse, warranted sound,
and the next day or the day after, rides or drives the ani-

Y 2

324 Itrflammation of the Lvngs.

mal unprepared for fatigue, and consequently unable
to bear it, by way of trial ; the day following this trial, or
ordeal rather, the horse refuses his food, blows a little,
and soon after manifests a severe attack of pneumonia,
of which, within a few days or weeks from his purchase,
he dies. An action is immediately brought against the
dealer. Some blundering, ignorant farrier, on the part
of the plaintiff, swears, that the animal, when opened,
was found " as rotten as a pear," and that he must con-
sequently have been diseased long before he was bought.
The result is, that the dealer is cast, and the gentleman
recovers his money. Now, in the generality of these
cases, the veiy reverse of this is the absolute truth :
the animal was perfectly sound at the time of purchase,
and was made otherwise solely by the exertion his
purchaser put him to ; and so far from the rotten-
ness of the lungs, or agglutination of them to the sides
of the chest, being proofs of the contrary, I have seen
the one produced in seventeen hours *, and know from
extensive observation that the other, viz. blackness and
engorgement of them with blood, or something like an
approach to mortification, (for rottenness is an expression
that has here no definite meaning whatever,) may take
place in the course of four and twenty. Indeed, when
pneumonia proves fatal, it most commonly does so in the
course of the first three, or four, or five days ; if it
continue beyond this, or there be any remission, it is
always a favorable indication. In these cases, the lungs
themselves, as I have just stated, are found nearly
black — of the color of the darkest venous blood, with
which they are prodigiously glutted ; the pleura also

' Vide Lecture xxxv. Dheases of the Plairn,

Injiammation of the Lungs. 325

displays a surface highly vascular, and adhesions are
occasionally discovered upon it.

Sometimes the case appeal s to terminate in resolution :
the symptoms gradually subside, and the animal does
not evince the least defect in respiration aftemards.
VVTien peripneumony has become protracted, although
all immediate danger has ceased, the remaining inflam-
mation is very apt to proceed to the impairment of
the texture of the lungs, and thereby to teiminate
■n some permanent disease, the existence of which
IS afterwards disclosed by the horse becoming thick-
l iiided, or a wheezer, or roarer, or by his not recover-
mg, although his appetite appears to be restored, his
wonted condition and spirits. The most common change
of structure that they undergo, is that of condensation
ir hepatization : the parenchyma is obliterated, as it
were, by the interstitial deposition of solid matter, so
that the lung on being cut puts on the appearance of
liver ; in this state, if it is immersed in water, it sinks to
the bottom of the vessel, nor can it be distended as usual
i)y insufflation. Now and then the inflammation takes
on a chronic form after a time, and spins out the malady
to a considerable length, yet leaving the animal, though
exceedingly debilitated, in a recoverable condition ; or it
dwindles into hydrothorax, or a tuberculous state of lung,
irailar to pulmonary consumption in the human subject,
I very common mode of ending of the last of which is
•glanders.

The treatment of this disease is not so simple as it is
generally conceived to be, if the veterinary practitioner
Ijo guided by those principles that regulate the practice
'^f the surgeon ; and, as far as my knowledge of pa-
thology extends, they are his only rational and sure

326 Iriflammation of the Lungs.

pilots to a successful result. Empiricism, a great obsta-
cle to advancement in all medical science, and the bane of
good fellowship among the members of either profession,
has extended its influence in an especial manner to the
treatment of pneumonia ; I feel it a duty, therefore, to con-
nect with the opinions I am about to promulgate, that I
have no motive in recommending them to notice but the
progression of that art which it has fallen to my lot, by
the publication of its principles, to labor in establishing,
in this country, upon the basis of science. In the first
instance, and the earlier the better, we must draw blood.
Seeing, at once, that the disease is an acute attack of
pneumonia, it is not even necessary to examine the
state of the pulse ; we may proceed directly to make
a large orifice in the jugular vein, or one in each of
them if the case is urgent, and take away from six to
eight or ten quarts of blood, according to the size and
strength of the horse ; unless he shew symptoms of
faintness during the detraction, in which case we ought
instantly to pin up the vein. Were we to be governed
solely by the state of the pulse, we should not bleed in
many of these cases perhaps at all ; for, as I observed
at another time, the pulse is often imperceptible at
the heart, and weak and indistinct at the jaw ; this,
however, arises from the gorged state of the lungs
and consequent plethora of the venous system —
a condition that venesection directly relieves ; so that
if we examine the pulse, we shall frequently find that
it is actually rising — growing distinct at the heart, and
beating with more freedom at the jaw, while the blood
is flowing. Sometimes the pulse will become strong
and bounding from bleeding ; but this may be considered
as a sign that too sparing a quantity of blood has been

Inflammation of the Lungs. 327

drawn, and therefore one that should induce us to
recur to the operation ; for we must take care not to
cease bleeding as soon as we have removed this sangui-
neous fulness, but to continue it until we have reduced
the action of the circulatory system down to a state of
direct or absolute debility.

After the first bleeding, we are to be guided chiefly, as
to the expediency of repeating the venesection, by the
pulse : at the same time, we are not altogether to disregard
other symptoms, and particularly the state of the respi-
ration ; if that continues unabated, and the pulse is undi-
minished in frequency and still strikes the finger sharply,
it is our duty to return to the operation. Probably,
this second phlebotomy may be required in the course of
four or six hours from the first; the quantity drawn
however should be less — from four to six quarts being in
most cases sufficient ; and whatever evacuations may
be indicated afterwards, ought to be likewise reduced —
about three, and even two quarts being as much as can
generally be taken with benefit : all this, however,
must depend so much upon the course and severity of
the symptoms, and the general condition and strength of
the patient, that it wouM be bordering on quackery to
pretend to prescribe in a lecture minutely in regard to
venesection.

Having bled the horse, what is the next step to be
taken? Professor Coleman, when I was at the Col-
lege, used to recommend the pupils to turn their pa-
tients out from stables ever so hot, and from being ac-
customed to clothing ever so warm, into the open air,
even in the midst of winter, relying on the benefit re-
sulting being in proportion to the severity of the change ;
Professor Peall, on the other hand, advises us, to

328 Injiammatioit of the Lmigs.

rub the surface of the body if it be cold until it becomes
warm, and to cover it well with woollen clothing, espe-
cially in cold weather. — Medio tutissimus ibis * .

That cold debilitates the force, and in many of these
cases the frequency of the circulation or, in the words
of the Schools, operates as a " direct sedative," I
admit; also, Jthat it may prove a valuable remedy to
the veterinarian in the course of his practice ; but that
this ^sudden exposure to it has a salutaiy influence in
horses laboring under pneumonia, it is my duty to say
that my experience does not (nor does the experience of
any Veterinary Surgeon that I know) verify : the me-
dical records of the Royal Horse Infirmaiy, the practice
in which has been more extensive than that in any other
British veterinary establishment, decidedly condemn
such treatment.

Though I am averse to turning the animal out, I re-
commend that he should be put into such a situation as
will admit an abundant and a continual supply of
fresh and cool air, where he can turn and put himself
into any posture that may be most agreeable to him ;
with which view, an airy loose box of all others is the best
place. At the same time that I take care to afford him pure
and cool air to breathe, I take the precaution to have him
clothed, not only to keep the surface of the body warm,
but, if possible, to excite perspiration ; and whether the
medicine I am in the habit of giving, or the clothing
does it, I generally succeed in promoting that smooth,
glossy state of skin which is the well-known effect of
augmented cutaneous exudation. In order to generate

* I believe that Professor Coleman has relaxed tlie severity of
this treatrrient. The practice adopted now at the Veterinary Col-
lege, is to turn the horse into an open shed.

Injiammation of the Lungs. 329

warmth in the extreme parts, a hood should be worn,
and the leas rubbed and bandaged with flannel.

The medicine I have been in the habit of giving for
twelve years, and upon which I repose now with con-
siderable confidence, is white hellebore. To describe
its operation, perhaps I cannot do better than advert
for a moment to the use of ipecacuanha, under similar
circumstances, in the human subject. That substance
is a nauseant, a vomit, and a sudorific, and is highly
serviceable in pneumonic aflPections, from the effects it
manifests in lowering vascular action, and promoting
diaphoresis and expectoration. Much in the same way
white hellebore appeai-s to operate : it excites nausea,
and will, if cai*ried farther, produce efforts to vomit \ it di-
minishes the force and frequency of the pulse with sin-
gular efficacy ; it abates all the inflammatory symptoms ;
and it influences, I myself believe, the action of the
perspiratory vessels, though I must confess I have
never seen actual sweating produced by it. Although it
is a remedy of the most active kind, alid one whose
operation demands unremitting vigilance, it is one that
we have most completely under command. I commonly
give it in the dose of a scruple or half-a-dram, and
repeat it every four, six, or eight hours, according to
the urgency of the case*. During its exhibition we
are to be continually on the watch for symptoms of
nausea — such as, the horse all at once evincing ex-
treme dulness, hanging his head in or under the manger,
and frothing a little at the mouth ; the pulse, however,

• R Veratri Rad. Pulv. 9j vel 3ft.
Pulv. Flor. Anthemidis 3ft.

Syr. Simpl. q. s. ut. ft. Bol. terlia vel quarta quaque hora
ejihibendus.

330 Inflammation of the Lungs.

which will be found to have sunk by this time to an un-
expected degree in force and frequency, will almost al-
ways give us warning of such a state, before these symp-
toms have made their appearance, so that we need not
carry the medicine thus far unless we are desirous of mak-
ing a greater impression. Having once affected the
pulse, I recommend that the dose be diminished, given
at longer intei"vals, or suspended altogether, according
to the pressure of the case — continuing or recurring to
its use only at such times as the pulse and respiration
appear to demand. To this account of the beneficial
operation of hellebore, I have much satisfaction in add-
ing the testimony of so scientific a practitioner as Mr.
William Goodwin, who informs me, that he has ad-
ministered hellebore extensively during the last winter
in His Majesty's stud with eminent advantage.

Let me observe here, that purging is a pernicious
practice ; and that 1 have rarely seen aloes given, even
in small or nauseant doses, without being productive of
mischief. Not many months ago, carbonate of ammonia
sprung up into notice as a " never-failing remedy" for
pneumonia. Being anxious to know to whom we were
indebted for this extolled innovation, I learnt that it
originated with a horse-dealer ! I was rejoiced to find it
was not a Veterinary Surgeon. The discovery was cer-
tainly worthy of the man, and when he dies I would
have inscribed upon his tombstone, Hicjacet auctor hujus
argwnenti !

The next part of the treatment consists in the use of
blisters. I have heard it said, that blisters by increas-
ing the pulse do mischief, and that rowels ought to be
preferred because they produce a deep-seated, and not
a superficial inflammation. This last is an argument

InJiammatioH of the Lungs. 331

that I must confess I am unable to sift scientifically ; and
as to blisters increasing the frequency of the pulse, I can
safely aver that it will not happen during the exhibition
of hellebore. For my own part, nothing would induce
me to relinquish the use of blisters ; by them, I believe
to have mitigated the poignant sufferings of many a
helpless brute, and to have contributed not a little to his
ultimate recovery : I own that this may not admit of very
ready demonstration, but if T may be allowed even to
reason analogically, it is no more than natural to main-
tain such an opinion. Ask a man wincing from the
lancinating pains of a pleurisy, whetlier a blister ap-
plied opposite to the part affected has relieved him ! — or
ask a surgeon whether he would insert a seton in the
side, with a view of exciting counter-irritation with the
utmost celerity and effect in acute pneumonic inflam-
mation ! — for the cases are precisely similar. Blisters
should not be exhibited until we have reduced the force
of the circulation by- the use of the lancet, and the fre-
quency of it by the administration of the sedative or
hellebore ball ; a repetition of them will be necessary
in order to keep up a continual irritation in the skin,
with copious discharge and subcutaneous effusion. I
always make use of the infus. lyttae, so that there is no
occasion to trim off the hair : from four to six ounces
are sufficient for both sides, which should be repeated
in the course of six or eight hours if no effect shall have
been produced. As to rowels, indeed, they do little or
no good during the acute stages of this disease, and for
two reasons : one is, that before the rowel acts it fre-
quently happens that the horse is dead, or is so far re-
lieved that you consider him out of danger ; the other,
that, if they do take effect, the discharge from them in

332 Injiammation of the Lungs,

the course of a few hours is so small, and the inflam-
mation they give rise to so circumscribed, that they are
not at all calculated to afford relief in these cases. One
blister, in my opinion, is worth in point of efficacy
half-a-dozen rowels *.

Some practitioners recommend us to apply blisters to
the legs ; but I am not yet quite satisfied how far the
practice is beneficial, and therefore I shall not take
upon myself to sanction it. I have seen it adopted in a
great number of cases, but it is somewhat difficult to
determine with what benefit to the animal ; thus much
however I have remarked, that it does not, if the case
be treated with hellebore, quicken the pulse from irrita-
tion ; and it most unquestionably must be regarded as
a propitious symptom, when the legs become warm and
swollen. If blisters to the legs be admissible under any
circumstances, it is when those parts are extremely cold,
and have resisted ordinary measures to restore a kindly
heat in them ; such as the use of flannel bandages, fric-
tion, &c. It is odd enough that those who have all along
been most hostile to the use of blisters to the legs
as well as the sides, should have advised us to plunge
these parts in hot or boiling water : this, to me, like the
preference given to a rowel because it is productive of
a deep-seated inflammation, is very unintelligible medi-

* Professor Peall closes his inquiry into the comparative
efficacy of rowels and blisters, thus : — " The experience however of
many years, has completely satisfied my mind, that all the advant-
ages that can be derived from rowelling in this disease, may be ob-
tained in a more cleaiily and less offensive manner, through the
medium of blisters."—" And I would, therefore, recommend the
blistering of the chest and brisket of the animal, as well as tlie
sides, in preference to the insertion of rowels in those parts."
Loc. cit.

Inflammation of the Lungs. 333

cal logic ; as I cannot therefore be expected to enter upon
the discussion of what I do not pretend to understand, I
shall wind up the point at issue (and in doing so con-
centrate my opinions) with this remark — that warmth
of the extreme parts is a desirable but not a primary
object in the treatment, and that we may make use of
any means to fulfil this indication so long as they be
not found to be productive of constitutional irritation.

LECTURE XXXIX.

On ^Ae Chronic Diseases of the Lungs.

I OBSERVED in the last lecture that pneumonia,
when it resisted the timely and eflficient employment of
suitable remedies, was apt to run into the chronic stage,
and that then it either terminated in hydrothorax,
which is its most frequent mode of destruction, or
gave rise to the formation of tubercles : hepatization of
the lungs may also be the effect of this form of disease,
but I am inclined to regard that as a more common
consequence of acute peripneumony. Having in a
former lecture treated of hydrothorax, I shall now make
a few remarks on the tuberculous state of these organs.

Should a protracted peripneumony, especially in an old
horse, degenerate into such symptoms as follow, or
should he enjoy intervals of apparent health and at
length return with such a relapse, we may have suspi-
cions that the lungs are, or are becoming, tuberculous :
— more or less quickness and difficulty of breathing, a
short cough, a small, quick pulse, defective appetite, a
gradual decline of condition, and with it, of strength
and spirits, coat dry and harsh, and some appearance in
the course of the disease of farcy or glanders ; and if

On the Chronic Diseases of the Lungs. 335

the horse coughs up and discharges from the nostrils
a clotted purulent matter, and that discolored and
fetid, vomicae also are probably present.

The tubercles comrnonly met with consist of little,
whitish, round, hard substances, inclosed in compact
cellular cysts ; when they are seated near the surface,
they feel like so many hard knots in the substance of
the lung in passing the fingers over the pleura. At
first there are but very few of them, and they are dis-
tantly lodged from one another ; but in the course of time
they grow very numerous, and are dispersed through-
out the parenchyma of one or both of the lungs. At
length, they grow soft, become converted into caseous
substances, and ultimately degenerate into ulcers, which
produce a fetid sanious matter that is mixed with the
pus and mucus of the bronchiae and cast off through
the nose. Not unfrequently we meet with large, white,
soft tubercles ; whether which be formed by the coalition
of those now under our consideration, or whether they
be a distinct species, I am at present unable to deter-
mine.

In other cases the parenchyma is studded with little
red tubercles, which, when cut into, have a liver-like
aspect. They vary from the size of a pea to that of a
marble. The first change these appear to undergo is
one also of mollification, during which they turn of the
color of the darkest venous blood ; the second, a con-
version of the black part, which originates and spreads
from the centre, into a yellowish white matter, like
cheese ; thirdly, they ulcerate and produce an ill-di-
gested pus, similar to that of the white tubercle, which
is likewise discharged through the bronchize.

We are not to suppose however that tuberculous

336

Bronchitis.

lungs are always manifested by outward signs of disor-
der : many old horses are thus affected who, though they
may be " touched in the wind," do a certain sort of
work very well, and preserve their condition under it.
In some instances tubercles lie dormant in the pulmo-
nary tissue for a number of years, and are at length by
an attack of inflammation or some other cause roused
suddenly into action. In other cases, their nature ap-
pears to be involved in what we call glanders vlxiA farcy ;
in relation to which I shall postpone their consideration
until I have occasion to treat of those maladies.

There is one other inflammatory affection of thes^
parts, which, as it more frequently assumes the chronic
than the active type, I shall speak of here, but for
which (as it has, with some other diseases, escaped the
pens of writers on farriery) I am at a loss for a name—
at least for one that will be recognised by the profes-
sion : probably, when we shall be favored with our new
nomenclature, it will come under the denomination of

Bronchitis.

It is, in fact, essentially the same disease as peripneu-
monia notha of the human subject, a name that has
been veiy properly proposed to be banished to make
room for the one above *.

In the generality of cases bronchitis originates in a
common catarrh, along with which, if it be mild, it may
run its course without our knowledge of its presence ;
at other times howevfer the respiration and pulse, and
the expectoration of muco-purulent matter by the nose
and, when th« .aninial colighs, iby the mouth, plainly

An Essay on Bronchitis, ^c. By Charles Badiiam, M.D.

Bronchitv!.

337

indicate to us that the disease has reached the lungs. The
generality of veterinary surgeons to whom you may talk
on this subject, will tell you that catarrh has produced
or terminated in inflammation of' the lungs — meaning
what I have described under that head, peripncumony ;
but a little reflection will show them that they are in
error, and, if that will not, a little dissection will con-
vince them of it.

If, then, you meet with a horse who, in addition to
I the ordinaiy symptoms of catarrh, has a more frequent
•respiration than natural, and an occasional wheezing
I noise from which he is relieved by coughing and expec-
ttorating a considerable quantity of mucus or muco-pu-
irulent matter, accompanied with febrile disorder, you
imay presume that he is the subject of bronchitis;
tthough, witli the exception of the wheezing noise,
((which by the bye is not always present,) I know of no
tsign by which you can distinguish it from cynanche
ttrachealis. This however is a point of no moment ; for,
bbarring the parts chosen for the application of counter-
iirritants, I know of no tittle of difference in their treat-
Kuent. Venesections, small but often repeated — ape-
rrient doses of aloes, in combination with hellebore and
tturpentine *, with which I sometimes conjoin calomel f ,
— blisters — rowels or setons — bran diet — and, some add,
tthe linseed drink, which will certainly not be produc-

• ft Aloes Ext. Vulg. Sift.

Pulv. Veratri Rad. 3j.

Terebinth. Vulg. 3ift.
M. f. Bol. Mane Vespereque sumendiis donee alvus purgetur.
t R Aloes. Ext. 3j.

Ilydrarg. Submur. gr. x.

Had. Veratri 9j.

Syriipi q. s. ut f. Bol. sumendusut supra.
PART II. Z

338

Thick Wind.

tive of liarm, are the reniedieis it ought to be encountered
with. For detail about regimen, I must refer to the
latter part of the lecture " on catarrh," and to certain
parts of that " on roaring."

To show that this is a disease that ought not to be
passed over, indeed to demonstrate that it is one of im-
portance, I need only remark, en passant, that what I
am going to speak of is, I believe, always a conse-
quence of it.

Thick Wind.

However unintelligible the title of this pari of my
lecture may appear to some, I believe it is suffici-
ently explicit to the horse man. The peculiar sound
that conveys to his mind the idea of thick wind, which
is only produced when the animal is put to exertion,
originates in the innermost parts of the lungs. Profes-
sor Coleman attributes it to an effusion of lymph into
the air-cells ; I am of opinion that it proceeds from a
thickening of the membrane lining or forming the cells,
and continued along the bronchial passages ; but the
genuine, unallayed cases that present themselves for
post mortem inspection are so few that it is not a very
easy point to determine*. Thus much respecting it
appears to me to be certain — that we may form a better
ratio symptomatum out of my exposition of its nature
than out of the professor's. Though the disease may,
and I believe often will be found to exist in the larger
branches of the bronchise, it is not into them that we

* A common accompaniment is hepatization of the lung, which
is a great impediment to a minute examination ; probably this de-
posit also contributes to the production of the sound, by opposing
the expansion of the bronchia.

Thick Wind.

339

are to look for a rationale of the symptoms, for their
calibre is too large to admit of obstruction or impe-
diment from a thickening of the lining membrane, but
into the smaller — the membranous ramifications, in
which the additional thickness, though really not
greater than in the large, so much diminishes the dia-
meter of the tube that the passage of air through it is
embarrassed ; and it is to the impetus with which
the air rushes through them that I would ascribe the
production of the noise, called thick wind : so that it
is in fact a species of roaring. I do not mean to assert
that there may not be other causes for this disorder, but
I believe this to be the more frequent one ; and it is
one which, from its nature, we certainly have but little
chance of removing. This shews us then how necessary
it is to endeavour to arrest, by every means in our power,
the inflammation — the proximate cause of the membran-
ous disorganization here present ; and during its attack
it is, and then only, that the disease can be said to be
within the reach of remedy. I have stated that roar-
ing even may result from this morbid alteration : my
father has made a preparation from the lungs of . a
roarer in which there is opacity — an unnatural white-
ness and thickening of the bronchial membrane, as far
as one can trace it with the eye, joined to hepatization
of the substance of the lung.

Unless the case was a recent one, and there still re-
mained symptoms of inflammatory action, it would be
the height of absurdity to entertain any notions of cure.
Should we, under these circumstances, be called to
treat thick wind, we shall mostly find that the symp-
toms of inflammation are ebbing fast, and that deple-
tion cannot do much good. I would direct my views

z 2

340

On Broken Wind.

chiefly to counter-irritation, and that should be long
and unceasingly persisted in.

On Broken Wind.

Few disorders have more attracted the notice of vete-
rinarians, in this as well as in former ages, than the one
I am now going to give a description of : speculations
and opinions of its seat and nature have been both numer-
ous and discordant. It would be a waste of time, and
foreign to my present purpose, to enter into an ac-
count of the many (I may say) idle conjectures that
have been started regarding its nature, or of the disgust-
ing operations and ridiculous farragos that have appear-
ed in print for its cure ; I shall therefore proceed at
once to point out the signs and symptoms by which its
existence may be known, examine the theory at pre-
sent entertained of its pi'oximate cause, and offer some
remarks on the treatment of horses that are the subjects
of it.

The symptoms of this disease are such as, when well
marked, leave no room for doubt of its presence ; so
that one who has seen but two or three cases of it, will
hardly ever afterwards be deceived in his diagnosis : in
fact, were I to tell a horse-dealer of the metropolis, or
a breeder of horses of Yorkshire, that he did not " know
a, piper," I should derogate perhaps more from his judg-
ment than if I had questioned his knowledge on any
other horse topic whatever. Two symptoms especially
guide us in our decision : — the state of the breathing,
and the nature of the cough, whether morbidly present
or artificially produced. Expiration is comparatively
long, protracted, and difficult ; inspiration short, sud-
den, a^id free ; the flanks, with a quivering action.

On Broken Wind.

341

gradually contract until they exhibit that appearance
called tucked tip, then, having compressed the abdo-
men to the utmost, they all of a sudden expand and
resume their former shape and relaxation : so that
much more time is occupied in the act of expiration
than in that of inspiration. To convey a correct notion
in words of the cough is more probably than one ought
to pretend to, though so peculiar is its sound that once
heard we shall not fail to recognize it in future ; it is,
strictly speaking, (if any cough can be called so) short,
at the same time feeble, and scarcely audible at a dis-
tance that a sound one would be distinctly heard : it
strikes one with the idea of its having come from the
top of the wind-pipe, or of having been attempted to be
suppressed in the larynx : in fact, it is the very re-
verse of a hollow cough. The cough is frequently fol-
lowed by a shrill sibilation, which reminds one at once
of the suffering of a human asthmatic : indeed, when this
peculifir sound is heard, it is as characteristic of broken
wind as it is of asthma. Although cough is generally a
concomitant of this disease, we are mostly compelled , in
making our examination of a horse, to produce one ar-
tificially, which may be done either by putting him to
any violent exertion, or by the more usual and ready
expedient of compressing his gullet. Indigestion, ac-
companied with troublesome flatulence, is mostly a con-
sequent disorder.

The theory of a disease consists, first, in discovering
its seat, and, then, in demonstrating its nature. In this
point of view, those original writers who have hitherto
attempted to develope the pathology of broken wind,
have, in my opinion, one and all failed. Being engaged
m making inquiries about the origin of what is consider-
d as the best existing theory of tliis disease, I was agree-

342

On Broken Wind,

ably surprised in finding the following authentic ac-
count in Dr. Rees' Ct/clopccdia, by the writer of an ar-
ticle entitled " Broken Wind." — " In the year 1795,
being engaged in the dissection of a grey mare that was
sent to the Veterinary College to be destroyed on ac-
count of this complaint ; on opening the chest, the
lungs appeared free from inflammation, being very
white ; and, as they appeared free from redness and in-
crease of colour, the general concomitant of disease, we
were led for a while to consider the lungs as not the
seat of the disorder, as others had done. (For several of
the pupils were present at this dissection). On cutting
into their substance, no inflammation was perceivable ;
on examining them more closely, we observed a small
bladder or vesicle on the outside of the lungs, in the
external investing pleuritic coat ; this was conceived by
some who were present to be a tubercle, and that tu-
bercles might be the cause of the broken wind. Su-
specting, however, from its appearance, that it was not
solid, but contained air, it was punctured, and it im-
mediately subsided. This instantly suggested to the
writer of this article, that the lungs were actually in a
state of emphysema, or that air was contained in u state
of extravasation in their substance, and which not only
seemed evidently the case in this instance, but we
have since fully verified it by examination and dissec-
tion of a considerable number of cases of broken wind,
and found that it is the constant appearance. This ex-
travasation of air in the substance of the lungs is per-
haps occasioned by a rupture of the air-cells, as sug-
gested by Mr. Coleman at that time, unless it is formed
in them, and thrown out by some morbid operation of
the blood-vessels, as sometimes happens in the intes-
tines and vagina ; for the exact way in which this em-

On Broken Wind.

343

physema arises has not been yet ascertained. It fully
explains the cause of the white appearance of the lungs,
the membranes being separated and divided by air lying
between them partially admit the light, also the puffy
appearance they make, and the crackling noise they
give on their being handled ; all admit of a ready ex-
planation by this discovery, and so do the symptoms
which attend the disorder ; for the common air escaping,
from a disease or a sudden rupture of the cells, into the
membranes composing the lungs, thereby compresses
and obliterates more or less the natural cavities destined
for the reception of the air, and thus occasions the effort
we observe to overcome this obstruction, and which
naturally induces the appearances we have described as
the symptoms attending this disorder : it also accounts
for its incurability, and the oppression which a full
stomach occasions. As the extravasation proceeds, the
complaint gradually, or sometimes suddenly, increases,
so as to be insupportable to the animal ; and at length
being quite useless, he is necessarily destroyed. In
some cases, the disease, without much increasing, may
exist for many years, and till the horse dies from other
disease or age. This white appearance of the lungs it
is that had deceived so long those who had been led
through curiosity to examine the lungs in this complaint;
it being so unusual to see any part in a state of disease
more delicately white than in its healthy state ; and sin-
gular it is that the extravasated air should not bring oft.
the inflammation and destruction of these organs."

To the writer of this paragraph then (who, if I mistake
not, is well known as a veterinary author) are we in-
debted for the fact, that the lungs in broken wind are em-
phi/semalous, and for the suggestion, that thej/ contain

344

On Broken Wind.

EXTRAVASATED (dv ; to the professor, for the opinion,
that the extj avasatmi is occasioned bj/ a rupture of the air-
cells. For my own part, I must acknowledge that my
opportunities of inspecting the lungs of horses broken-
winded, have been but few ; as far as my examinations
have gone however, they confirm this emphysematous
state of lung ; of which the vesicular appearance of the
pleura (a very general accompaniment, I believe) affords,
at least, presumptive evidence ; and as the secretion
of air is a point in pathology that yet seems to admit of
some doubt, it appears to be but fair to conclude with
the professor, that the cells are ruptured. But what
will these pathologists say, if I produce to them two
cases, neither of which was broken-winded, and yet in
them both the lungs were emphysematous * ?

* The first is that of a bay horse, that was the property of W.
Harvey, Esq. of Eltham. After a brisk run, late in the day, on the
9th of November, 1822, with the Surrey fox-hounds, this horse was
taken so ill on the road home that Mr. Harvey had four quarts of
blood drawn from him. On his return home he grew worse, showed
symptoms of pneumonia, with which prevailed obstinate constipa-
tion of the bowels. This was overcome however, and his breathing
had become so tranquil, and the pulse had sunk so much, that
hopes were entertained of his recovery up to the morning of the 14th,
when he relapsed into his former state of restlessness and pain, and
died at four o'clock p.m. On dissection, the spleen was found
preternaturally large, though of healtliy aspect. The liver was pale.
The cavity of the pericardium contained a pint of fluid. The right
lobe of the lungs was sprinkled with large, while, soft tubercles,
was of a pink color, and presented several large bladders of air which
raised the pleura from its surface. Mr. King, Surgeon at Eltham,
was present when the horse was opened. Mr. Harvey, who is well
known in the Surrey field as one of the most forward and resolute
riders in it, has assured me that he never met with a better hunter
or a better winded horse.

On Broken Wind.

345

Now, in these cases, whence was the air derived ?
It certainly cannot be said to "have been extravasated
air, for there was no breach whatever, either in the air-
vessels or air-cells. And yet the lungs in the last case
had the same pale, bloated aspect, the same crackling,
emphysematous feel, that they have in broken wind !

The next was a case admitted into this infirmary on the 5th of
February, 1823. The symptoms indicated disease of the chylo-poie-
tic organs, but of which of them, or of what nature, it was very
obscure. At one time the hver was supposed to be the chief seat of
the disease; at anotlier, the mesenteric glands were thought to be
affected. His pulse ranged from 50^ to 60° ; but he had no apparent
derangement in the functions of respiration. Latterly, he grew
; iiin, wasted away day by day, and died reduced almost to a skele-
ton on the 1st of June. The examination of his body excited more
than ordinary curiosity, and was conducted with special nicety and
care. The mucous coat of the stomach exhibited those marks of
patchy inflammation which it does from the application of poison.
The peritoneal coat of the larger intestines was begirt with similar
broad red patches. The liver was the chief seat of disease — its stnic-
ture altogether changed, and its color, as well as that of the bile, a
ilull or dirty green. Twenty ounces of water were measured out of
the pericardium. So perfectly bleached were the lung and its pleura
on the left side that, on a superficial view, they appeared to contain
no blood whatever : when contrasted with the left lung, which had
the usual healthy aspect, it exceeded any thing of the kind I had ever
seen before. Both, the right and left lungs presented several bladders of
air upon their surfaces, two or three of which were as large as apples cut
in halves. The pleura was cleanly and completely detached by air from
the lung; the connecting cellular membrane having been absorbed.
The integrity of the lung in these places appeared to be imimpaired.
Inflation of thelung to extreme distension produced no visible altera-
tion in these bladders, although the experiment was several times
repeated. On minute examination of them, the air appeared to
have proceeded from the parenchyma ; for, by compression, they
could be rendered lax, although no air was found to escape exter-
nally.

346

On Broken Wind.

If the fact, that the air-cells are ruptured in broken wind,
now one of thirty years' standing, rest upon the firm basis
of actual and repeated examination and experimental
inquiry, then the inevitable conclusion is, that these
cases were of a different nature, and, as such, I beheve,
have hitherto had no parallels given publicity to. But
how are we to reconcile this theory with what I have
now to state on the authority of my father, whose op-
portunities to investigate morbid structure have been ex-
ceeded by very few in the profession ? — and that is, that
he has found the lungs of some broken-winded horses
free from any emphysema whatever, or other appearance
indicative of ruptured cells. To which I may add, that
Mr. Sewell has framed a theory on the subject
which has a totally different ground-work.

With a view, however, of throwing some additional
light on the subject, I shall for the present wave these
facts, and adopt the prevailing theory of the day ; this
will enable me to inquire what sort of a ratio symp-
tomatum can be deduced from it — how far it tallies with -
the causes and symptoms of the disease, and its ef-
fects upon the system, and how far it bears us out in
our present mode of treatment. B lumen bach says,
(speaking of human lungs) that if air be forcibly thrown
into them, the air-cells will be ruptured ; but I am not
aware that any writer makes mention of such a case
happening during life ; though there are some related of
vomicae and ulceration of the cells giving rise to emphy-
sema. But, if we are to consider this disease as a rup-
ture, perforce, of the air-cells ; it appears to me that this
theory will, by no means, serve to account for many of
the facts connected with broken wind. Instead of the
disorder manifesting itself on a sudden, which it ought

On Broken Wind.

347

to do, if it consisted in a lesion or rupture of the cells in
consequence of some violent effort in breathing;, its ap-
proach is gradual ; it is generally long preceded and
prognosticated by a dry husky cough ; hence it is very
common to say, that such a horse has a broken-winded
ough. Horses that are greedy feeders, that consume
daily large quantities of gramineous provender and
water, and that are irregularly worked, are the sub-
jects of this disease ; in a word, such as feed grossly
and take exertion upon a full stomach : neither post
horses, nor coach horses, have it so frequently as car-
riage horses, farm horses, and hackneys ; because the
former consume but little hay, are duly watered, and
are regularly worked and kept in wind. This fact has
been brought forward in support of rupture ; the horse,
(say they) not being able to breathe with his usual free-
dom, makes some violent efforts in one of which the
air-cells become lacerated. Now, let us examine this
point — let us first inquire what are the circumstances
most favorable to a rupture. It appears to me, that, to
burst the cells, the air should rush in with unusual cele-
rity and impetuosity, and the chest should be in a state
to admit, at the time, of the fullest expansion of the
lungs ; at least, this would undoubtedly be the most ef-
fectual method of lacerating them in the dead, and I
cannot see why it should not be in the living body.
As far as distension of the belly can operate, it would
appear to me rather to counteract this effect than to
f avor it ; for, if the diaphragm cannot recede with its
usual freedom (and we know that the auxiliary inspira-
tory powers — the muscles attached to the shoulder, can-
not act while the fore legs are in motion) how is the
chest to be dilated to an extraordinary degree, or the

348

On Broken Wind.

lungs to be preternaturally expanded ?— ergo, how is this
deep and violent inspiration to be made ? But, the
reverse of all this w^ill not infrequently happen :— broken
wind has been known to occur in the stable, and in the
strawyard ; and I have been credibly informed that horses
havebeen taken up from grass with the disease upon them,
that were in health when they were turned out : these
horses, most assuredly, will glut their stomach and
bowels prodigiously, but, then, they are not very likely
to exert themselves afterwards of their own accord so as
to burst the substance of a healthy lung. Again, admit-
ting that the air-cells are ruTptmed per force, I cannot see
why Nature should not, in some of these cases at least, re-
new the integrity of the lung. I cannot conceive that rup-
ture can happen without extravasation of blood, as well as
air, which blood might in some cases prevent the effusion
of more air ; at all events, one would think that adhe-
sive inflammation would ensue, that the extravasaled
air would be absorbed, and as the restorative powers of
the horse are great, I repeat I am at a loss to understand
why some of these horses do not recover ; which, it is
universally known, none ever do. For these various rea-
sons, for my own part, I am by no means satisfied with
the present theory of broken wind.

On the other hand, it must be acknowledged that
this mode of reasoning serves us very well to ex-
plain the short and sudden inspiration followed by the
comparatively long and tiresome expiration ; for, as
soon as the air has left its cells and become diffused
through the parenchymatous texture, the animal is
compelled to make use of great expiratory efforts — to
draw his flanks in considerably more than he did before,
to squeeze this air back into the ruptured cells, which .

i

Oh Broken Wind.

349

it must all enter again before it can be expired ; but
Uaving once, though perhaps imperfectly, effected this,
the vacuum formed afterwards by inspiration seems to
ipproach more to a perfect one than even that in he^lthj
for the air now rushes in with greater celerity than ever.
Professor Coleman generally prefaces the exposition of
liis opinions on this subject, by saying, that those who
named the disease broken wind, have left us reason to
conclude that they were acquainted with its nature —
tliat they knew, in fact, that there was something
hroken. But I view this in a different light alto-
gether ; for, if we only remember one of the predomi-
nant symptoms of the disease, which shall be name-
less here, and then advert to the vulgar meaning at-
tached to the phrase "to break wind," we shall have,
I think, quite as good, if not a better derivation for
this appellation ; for, in those days, the farriers were
not much given to morbid anatomy !

Last year, Mr. Cherry, happening to have a strik-
I ugly well-marked case of broken wind in his infirmary
stables, was kind enough to inform me that he would
have the horse destroyed any day I would be present.
Accordingly, no sooner was life extinguished than we
i emoved the lungs, trachea, and larynx from the body,
and submitted them, as yet steaming with vapor, to
close and careful examination. The general aspect of
'■very part was that of perfect health; only the lungs
w ere paler (being of a light pink hue) than they generally
ure at this time of Hfe — eight years old. The pleura
was every where in apparent health but in those places
in which it was elevated, by air underneath, into ve-
sicles ; there it was opaque and whitish, which, at
first view, might have led one to believe that those

360

On Broken Wind.

vesicles were so many white tubercular eminences.
The vesicles were most numerous and conspicuous
upon the anterior lobuli ; but both lungs had, in every
part, a crackling, emphysematous feel, and the air they
contained could be readily made to traverse their sub-
stance by compression. They were remarkably buoy-
ant in water ; particularly the anterior lobuli. When
inflated, the air appeared to distend their parenchyma ;
but, what was very remarkable, it neither increased the
number of the vesicles, nor enlarged them that already
existed. After inflation, the whole lung became still
paler and crackled more when squeezed with the hand :
this Mr. Cherry thought arose from the rupture of
more cells ; I had however, and still have, my doubts
on that point. The bronchial and tracheal membranes,
though of their natural color, were much thickened * ; the
membrane covering the arytenoid cartilages was likewise
thickened, and studded with little hard papillary eminences.
There was no alteration in the form of the trachea. I
shall leave this case without remark, and the subject, as
it stands, without further comment : I wish to withhold
my own opinions until I shall have had time and op-
portunity to ratify or falsify them by further observation
and experiment.

About the treatment of this disease I have but little
to say. Did I believe that there was lesion of substance,
and that this lesion was the effect of a violent effort in
breathing however, I certainly should prescribe for
the case if recent, and I conceive with some pro-
spects of benefit ; for, if the torn parts were glued toge-

* I should like to know if this is a constant appearance— if it
be, I think it will throw much light on the pathology of broken wind.

Ob Broken Wind.

351

ther again, (and I must repeat, I camiot divine why they
should not be in certain cases under proper treatment,
in the same way in which other wounds of the sub-
stance of the lung are,) the only mischief that would
ensue probably would be the agglutination and solidi-
fication of a few air-cells : the extravasated air, like the
air in emphysema, would, I should think, be speedily
removed by the absorbents. But, here all medical
treatment is out of the question ; a horse once broken-
winded is ever so : in other words, we have no cure for
broken wind. Not being able to remove we must
endeavour to mitigate the complaint ; for broken-
winded horses, unless they are inveterate cases, may
by proper management be rendered very serviceable
for a variety of purposes : indeed, they are occasionally
hunted imder a judicious regimen with less inconveni-
ence to them than we might a priori be led to suppose.

It is by attention to the feeding and the exercise of
such a horse that we shall enable him to do his work
with comparative ease — without those painful sobs for
breath which, to the ear of his humane rider, most
loudly call for a relaxation of exertion. Not that there
is any thing especially applicable to broken wind in the
mode of feeding I am about to recommend ; for it
ought to be adopted in all cases of defective or embar-
rassed respiration, and with some horses would be prac-
tised with advantage even in a state of health. The
object we have in view in putting such a horse under a
prescribed regimen, is at all times to keep his stomach
and bowels free from distention, but, above all, to take
care that these parts are not in a state of fulness when
he is put to work ; for, if they are, the diaphragm,
from the pressure of the stomach and colon against it.

352

On Broken Wind.

cannot recede to the required extent, and the conse-
quence is difficult and laborious breathing as soon as we
begin to make the animal exert himself. Give him then
but little hay, and give him that little at night, after he
has done his work ; feed him mostly on corn, for that
contains more nutriment than hay, and occupies a
much less space. I do not see the necessity for depriv-
ing a broken-winded horse of water in the unfeeling
manner in which it is commonly done ; any considera-
ble quantity should certainly not be given when he
is about to go to work ; but if he be watered fre-
quently— four, five, or even six times in the course of
the day, and his provender itself be made wet, he
will not take large draughts ; and when we come to
learn the short time that water remains in the stomach,
we shall see less reason for enforcing this insalubrious
practice. Broken-winded horses always work best
when fed with green or succulent food ; carrots, parsnips,
Swedish turnips, mangel wurzel, and (some say) pota-
toes, are esteemed particularly wholesome for them ; and
they are so, and for these reasons :— because they
are very nutritious, are of light digestion, "very mildly
laxative, and contain much water ; so that the animal
drinks but little, and what he eats remains but a short
time in the stomach and bowels ; a circumstance that
greatly tends to his relief. Indeed roots, such as I
have mentioned, I feel inchned to beheve, would prove
by far the preferable food for these horses ; for their
digestion is never good, as the flatulent state of their
bowels evinces, as well as the roughness of coat
and lowness of condition many of them exhibit,
though this last effect may be in part attributed to
the imperfection of the respiratory functions. If oats

On Broken Wind.

353

ire given, they ought to be bruised and wetted, and if
liay is, it ought to be of the best quality, (of meadow,)
and that cut into chaff : saintfoin, lucerne, and clover,
unless green, I would never feed a bad winded horse
with .

At times, when the animal appears to suffer from a
return of symptoms (and this fact proves that broken
wind continues its progress, whether it consist in ex-
tension of rupture or not) small doses of aloes alter-
nated or conjoined with smaller ones of calomel, will
prove very beneficial ; I have also practised small vene-
sections, when the relapse was at all violent, with de-
cided advantage. Mr. Sew ell is in the habit of giv-
ing digitalis, in these cases, in doses of half-a-dram or
a dram ; and in one horse whom I saw under its influ-
nce, the breathing was very much tranquillized by it ; as
may be anticipated, however, the relief is only tem-
porary.

Before I quit this subject, I cannot forbear exposing
o censure that disgraceful and disgusting practice of
making an artificial anus, with a view of relieving the
flatulent condition of the large intestines — the farriers'
broken wind. Sometimes the sphincter ani is com-
pletely divided, and the unfortunate beast becomes a
loathsome spectacle from not having the power to close
the anus and retain the fcEces. I am not aware how-
ver that it is practised at present ; at least I hope not
wherever the Veterinary College has a representative.

I'AKT II,

LECTURE XL.

On the Heart.

The heart may be defined to be, an involuntary,
hollow muscle, contained in the thorax, the use of
which is to circulate the blood.

It is placed about the centre of the cavity of the chest,
between the divisions of the lungs. Its base, which
is opposed to the bodies of the 4th, 6th, and 6th dorsal
vertebrse, is suspended from the spine by the principal
venous and arterial trunks of the body ; its apex,
which is inclined to the left side, hangs loose and unat-
tached, within the cavity of the pericardium, nearly in
a line with the sternum, and points to the diaphragm,
with which at every expiration it must come in con-
tact.

Before the heart is removed from the thorax, I shall
make some observations on the membrane that sur-
rounds and conceals it. This is named the pericardium.
This membrane, which is fonned into a loose sac, has
not the same outward aspect as the pleura : — it is white
and opaque ; it is also thicker in consistence, and
stronger than that membrane. It is composed of two
layers, intimately united by cellular tissue. The ex-
ternal one is dense and fibrous, is possessed of the

On the Heart.

356

chief strength of the membrane, and is attached below
by several ligamentary cords to the sternum and ten-
dinous part of the diaphragm, and above to the roots
of the large blood-vessels at the base of the heart, upon
which we lose sight of it altogether : the sides of it are
clothed and additionally strengthened by the adhesions of
the pleurae. The internal layer is fine and cellular, exhi-
bits inwardly a smooth, polished surface, and appears
to be similar to other serous membranes in its intimate
texture and organization ; it not only lines the exter-
nal layer, and gives a covering to the roots of the large
blood-vessels, but is reflected from them upon the heart
itself, to which it forms a close and complete tunic : so
that the heart is absolutely out of — above the cavity of
the pericardium ; in fact, it is situated precisely the
same in regard to this membrane, as the human head
is in a double night-cap.

The arteries of the pericardium secrete into its cavity
a pale yellow, serous fluid, denominated the liquor pe-
ricardii : this lubricates the contiguous surfaces of the
bag and preserves them against the effects of friction.

The pericardium confines the heart in its proper
place, sustains the reciprocal action of it and the
lungs and prevents their interference, and protects the
organ from surrounding impressions. I shall now de-
tach the heart, and take it out.

The form of the heart is that of a cone ; but its shape
and general appearance are so familiar to every one that
I shall say nothing more about them here.

This organ varies a little in size in different subjects :
its ordinary weight is about six or seven pounds.

For the convenience of description, the heart may
be divided into its base, body, and apex.

2 A 2

356

On the Heart.

It is also said to have two sides, each of which con-
tains two cavities : — the two superior cavities (from hav-
ing been likened to the ears of a dog) have been de-
nominated auricles ; the two inferior have been named
ventricles. Their boundaries are marked externally by
deep excavations, which are filled with fat ; the limits of
the ventricles are likewise pointed out by furrows upon
the body of the heart, containing fat, continuous in
substance with that which is deposited above. This fat
is more abundant in old than in young horses.

The heart owes its smooth, glossy aspect externally
to its thin duplicature of pericardium, which is every-
where in such intimate adhesion with its surface, and so
transparent, that its parietes are too plainly demonstra-
ble through it to require that this membrane be stripped
off.

The sides of this organ, commonly distinguished by
the epithets, 7-ight and left, would more properly be de-
scribed, in allusion to the relative situation of their ca-
vities, as anterior and posterior ; for the right auricle
forms the upper and fore part, turning its apex to the
left side ; and the greatest part of the left auricle is
apparent behind, though its apex is also turned to the
left side, and is inclined downward. The ventricles,
being situated under their respective auricles, face con-
sequently, like them, forwards and backwards. Though
the auricles are essentially the same in structure as the
ventricles, they differ from those parts in exterior ap-
pearance, in bulk, and in the substance of their parie-
tes : they are of a pale red color, are very uneven,
when distended, upon their surfaces, and are indented
-along their inferior borders ; whereas the ventricles are of
a dull red or deep flesh color, are smooth and even upon

On the Heart.

357

their surfaces, and of themselves compose three-fourths
of the organ.

The right auricle, generally found full of blood after
death, is lined by a fine, vascular membrane, and pre-
sents internally a polished surface, the regularity of
which is internipted in places by many fleshy promi-
nences, named the musculi pectinati ; between which are
numerous little, sinuses, or cul-de-sacs, that, as well as
the fleshy pillars themselves, vary much in size, and
are most numerous and remarkable within the appendix::,
or ear-like portion of the auricle, where they form to-
gether a reticulated structure. Three venous trunks
terminate in this cavity : — the vena cava anterior opens
into the superior and posterior part of it ; the vena
cava posterior opens into the inferior and posterior
part; and the coronary vein just below it. The vena
azygos forms a junction with the anterior cava just as
the latter pierces the auricular parietes. Between the
openings made by the two venas cavae, there is a promi-
nence that is usually called the tuberculum Loweri. There
is a deep sac or sinus at the entrance of the posterior
cava ; and between this and the mouth of the coronary
vein, a crescentic valvular flap, which projects half
way over the mouth of the latter vessel. The right
auricle has a free communication with the right ventri-
cle by an aperture of large size, called the auricula-
ventricular opening.

One auricle is divided from the other by a muscular
partition, denominated the septum auricularum ; in which
may be seen, when the part is held to the light, an ellipti-
cal inlet of semi-transparent membrane, crossed in places
by fleshy fasciculi, which takes the name of fossa ova-

358

On the Heart.

lis: in some subjects there is a small aperture through
it, and this is all that remains of the foramen ovale.

The right ventricle is redder and considerably thicker
in substance than the right auricle : like it, it commonly
contains after death a large coagulum of blood. It is
likewise lined by a smooth, polished membrane, and has
within it numerous Jieshy pillars, which, instead of being
reticulated as those are in the auricle, are disposed lon-
gitudinally. In addition to these there are three conspi-
cuous fleshy prominences, from their size named the car-
need columncc, from which several little tendinous cords,
cord(c tendinetz, proceed to the edges of three membranous
and fibrous productions (sometimes distinguished by the
name of cortina tendinea) that close the auriculo-ventricu-
lar opening : the apparatus altogether forms the valvula
tricuspis. Other cords, similar to the cordse tendineae,
but stronger than they, pass between the outer wall
and the septum. The pulmonaiy arteiy emerges from the
upper and back part of this cavity ; and its mouth is
guarded by three semilunar valves, which present little
pouches within the cavity of the vessel : these valves
consist of doublings of the lining membrane of these
parts, infolding, about the middle of their loose edges,
three small granular substances, described as the corpus-
cula Arantii. Opposite to the valves, three depressions
are apparent in the coats of the vessel : these are xiamed
the sinus Valsalva.

The left auricle is smaller than the right, and has
thicker parietes. It contains in general but little blood,
and in some subjects none. It presents nearly the same
■aspect internally as the right. It has not so much of
ilie reticulated structure however — fewer musculi pec-

On the Heart.

369

linati ; what there is, is more strongly marked, and is
principally confined to the appendix. 'The pulmonary veins
terminate by four openings in the superior and posterior
part of this cavity. The auriculo-ventricular opening is
somewhat larger than that of the right side, and is ra-
ther square than round. Now, that the auricles are
both laid open, the septum auricularum, fossa ovalis, and
foramen ovale, may be distinctly viewed*

The left ventricle, though smaller within, is longer,
and more prominent and extensive without than the
right : it forms, of itself, the apex cordis. Its outer wall
far exceeds in thickness that of any other cavity of
the heart ; it is thrice that of the right ventricle. Its
musculi pectinati appear mostly upon the septum, within
the apex, and under the valves. It has but two car-
nece columnee, but they are very bulky and project much
into the cavity. Its auriculo-ventricular opening is
only furnished with two valvular productions ; in other
respects the cortina tendinea and corda tendine<z resemble
those on the right side : this valve is called the valvula
biciispis vel mitralis. The aorta takes its rise from the
upper and fore part of this ventricle, and, concealed at
its origin by the pulmonary artery on one side and
venag cavae on the other, makes its exit close to the
spine. The mouth of the aorta is shut by three semilu-
nar valves, similar in formation and disposition to those
at the origin of the pulmonary artery : but the sinus
Valsalva are much larger and deeper. Just above two
of them are seen the mouths of the coronary arteries.
The ventricles are divided by a thick fleshy partition
called the septum ventriculornm.

Though the heart may be said essentially to consist of
tleshy fibres, a tendinous structure is demonstrable in its

360 On the Physiology of the Heart.

body, which appears to be the common medium of attach-
ment of its auricles, ventricles, vessels, and valves to
one another. The fleshy fibres, composing the parie-
tes of the auricles, stronger in the left than in the
right, are disposed in every direction ; those that form
the walls of the ventricles, for the most part, appear to
run longitudinally and obliquely, and, many of them,
in a spiral manner. These fibres are more slender than
those of other muscles, and are more intimately and
firmly compacted ; the cellular tissue also, uniting them,
is finer, denser, and less in quantity.

The heart is supplied with blood by the two coronary
arteries — the first branches given off from the aorta.
Its veins pour their blood into the coronary vein, by
which it is returned into the right auricle. Its nerves
are derived from the cardiac plexus.

On the Physiology of the Heart.

In the centre of the body is placed the heart, by whose
concentrated muscular power blood is made to flow into
every part of the sanguiferous system, and perform that
regular circuit which in common language is called the
circulation. There may be said to be two circulations :
— the greater, or that course which the blood takes
over the body generally ; the lesser, or that which it
runs through the lungs only ; it is usual however to
consider them but as one, and to describe them toge-
ther as the circulation of the blood.

In giving a description of the circulation, it is of little
importance where we begin : — whether we consider a
volume of blood as being poured into the auricles,
after having completed its two separate courses ; or
whether we take it as it mounts from the ventricles in

On the Pkysiology of the Heart. 361

order to commence another general circuit ; as it is
more common however to adopt the first of these me-
thods, I shall make a beginning with the right auricle.
This cavity having received a certain quantity of blood
from the anterior and posterior vense cavae, contracts
and discharges that blood into the right ventricle, which,
by a similar effort, propels it into the pulmonary
artery ; and it is while circulating through the minute
divisions of this vessel that it receives the change the
nature of which I endeavoured to explain in a former lec-
ture. From the extremities of the pulmonary arteries the
pulmonary veins receive it, and convey it, through the me-
dium of four trunks, into the left auricle : and thus is
complete the lesser circulation. This cavity, being distend-
ed, empties itself into the left ventricle, by whose action
the blood is impelled with considerable force into the main
trunk of the arterial system, the aorta, the innumerable
branches and minute ramifications of which distribute it to
every organ and every part in the body. Having arrived
in the extreme arterial capillaries, and served the various
purposes of nutriment, secretion, and repair, it is received
by the radicles of the veins, by them conducted into the
larger venous branches, and at length transmitted into the
venae cavae, anterior and posterior, by which it is poured
again into the right auricle — the part whence I set out in
niy description.

Let us next inquire what are the particular functions of
each part employed in the circulation of the blood.
The uses that the auricles serve are two-fold. In the
first place, they are reservoirs — they receive the blood as
it flows back from the veins, and retain it until enough
has collected to distend the ventricles. The importance
of their office as such will be manifest to us if we but for a

362 On the Pki/sivlogy of the Heart.

inomeut suppose the heart to be constructed without them.
Had the blood, for instance, been immediately poured
by the veins into the ventricles, not only would the cir-
culation have been subject to frequent interruptions and
intermissions, but every now and then it must have
stopped altogether from the stagnation of blood in the
larger venous trunks, which vessels would have been
very liable to rupture from over distension : in this point
of view, some anatomists have regarded tlie auricles as
mere dilatations of the largest veins. The other function
of the auricles, is to contract when full and impel their
blood into the ventricles. To convince ourselves that their
action simply consists in this, we have only to examine
their parietes, and compare them with those of the ven-
tricles j indeed, they little exceed in thickness those
of the venae cavae ; nor was it necessary, since they are
not required to exert more force than is sufficient to
discharge their blood into the cavities beneath them.
The systole and diastole of the auricles are perfectly
synchronous ; i. e. they receive their blood from the
veins at the same intei"val of time, and they contract
upon it simultaneously. And it follows, as a natural
consequence, that the states of expansion and contrac-
tion in the ventricle swill likewise be synchronous ; so
that when the auricles are contracted the ventricles
are dilated, and vice versa. When an auricle contracts,
all its sides are brought nearer together ; in other words,
its cavity is diminished pretty uniformly in all its di-
mensions ; so that the blood within it, has as much ten-
dency to flow back into the veins as it has to flow down
into the ventricle beneath it. Reflux however is pre-
vented by (it is supposed) the continual undulating
force that the returning blood opposes to that already

On the Physiology of the Heart. 363

poured into the auricle ; for we do not find that any
valvular apparatus is at this part provided for the pur-
pose.

The ventricles, the functions of which I shall now
consider, take a far more active part in the circulation
than the auricles ; by some physiologists, indeed, they
have been regarded as the only agents employed in pro-
pelling the blood over the body ; but it is highly proba-
ble (as I have already endeavoured to shew *) that they
are much assisted in this operation by the arteries. The
substance of their parietes clearly demonstrates that they
must take a very efficient part as circulatory agents ; in-
deed the comparative strength of their muscular fibres
lead us to believe, that they are respectively capable of ex-
erting a mechanical force adequate to the greater and
lesser circulations ; but, I repeat, it is improbable, in
my opinion, that they unassisted circulate the blood, or,
that the blood-vessels themselves are altogether passive.
During the contraction of these cavities, all retrogade
motion of the blood is prevented by the valves placed
within the auriculo-ventricular openings 5 on the right
side by the tricuspid, on the left by the mitral valve ;
and these valves are unequal in strength in conse-
quence of having to resist diflPerent degrees of force :
the force of the left ventricle, for example, being greater
than that of the right, the mitral valves and their ap-
pendages are thicker and stronger than the tricuspid.

By the powerful action of the left ventricle then, blood
'is propelled into the aorta, the numerous branches
of which are already in a state of -fulness, and con-

* lu Part I. Lect. iv. On the Pliysiologif of Arteries.

364 On the Physiology of the Heart.

sequently cannot receive more blood without becoming
proportionably surcharged. Now, it is at this pe-
riod that the elastic power of the arteries comes into
play, and assists, in a manner I have already described,
in propagating the momentum given to the blood by the .
heart : and, as at this time the arteries may be said to
be in a state of systole, it follows that their diastole is
synchronous with that of the auricles, but alternate
with that of the ventricles. The systole of the ventri-
cles is supposed to occupy about one-third of the time
of the action of the organ altogether.

The heart, like the arteries, is known to pulsate : by
which I mean to express its beating, with certain de-
grees of regularity and force, against the left side of the
chest. This effect of the heart's action has been ac-
counted for in various ways ; the best explanation how-
ever of it appears to be this : — that its apex is forcibly
driven against the ribs of the left side, during the sys-
tole of the ventricles, in consequence of the distention of
the auricles and the re-action of the large arteries im-
mediately connected with its base, which are at this
instant surcharged with blood. I have already given a
detail of the variations of the pulse *, so that it will not
be necessary to enter upon the subject here : all I wish
at present to bring to mind is, that the pulse in health
does not beat with the same frequency in various
classes of animals, nor at different periods of life in
the same individual animal. Estimating the standard
pulse of the horse at forty -five beats in a minute, and
supposing that the left ventricle expels six ounces

* Vide Lecture On t/ie Fhysiology of Arteries.

On the Phi/siology of the Heart. 365

of blood at every pulsation, it follows that two hun-
dred and seventy ounces will pass through this ca-
vity within the space of one minute, and above
a thousand pounds in the course of an hour ; a calcu-
lation that may serve to give us some idea of the ex-
tent of the disturbance which the variations of the
pulse must occasion in the regular distribution of this
fluid, and in its supply to organs in general, and one that
will in some measure account for the derangement
of the system accompanying unnatural vascular action.

Some physiologists have endeavoured to ascertain the
force of the heart's action ; but the discrepance of opinion
apparent in their estimates, leads one to suspect that dif-
ficulties very considerable, if not insuperable, attend
such an inquiiy. Blumenbach says "the impetus
of the blood passing from the heart, may be conceived
by the violence and attitude of the stream projected from
a wounded artery, large and near the heart. I have
seen the blood driven to the distance of at least five feet
from the carotid of an adult and robust man." The
same author observes, that the impulse imparted from
the heart to the blood is communicated to the arteries
to such an extent that it is remarkably evident in those
branches which can be explored by the fingers and which
exceed one-sixth of an inch in diameter. The influence of
the heait's action, however, is probably extended through
the capillary, if not through the venous system ; though
the impulse conveyed to the blood in the latter is too
faint, in consequence of its remoteness from that organ
and the interposition of the capillaries, to produce puls-
ation. It has been proved too, I think, that the heart
further aids the return of the blood through the veins by

360 Om the Physiology of the Heart.

suction, originatmg in a power of self-dilatation inherent
in the auricles, which they exert at the very same inter-
val of time that it is impelled into them by the vis-a-
tergo. So that altogether we cannot too much admire
the ingenuity displayed in the construction of this little
organ, which, at the same time that it manifests a truly
astonishing power in the propulsion of the blood, is by
no means in an inconsiderable degree accelerating the
reflux of it, and thus is acting at once both as a forcing
and a suction pump.

The cause of the heart's action is a subject that has
much occupied the attention of writers on physiology,
some of whom, in too hastily taking up their positions,
appear to have disregarded many of the phenomena
connected with it ; for my own part, without entering
into the discussion of discordant opinions, or agitating
unsettled questions (from which I refrain as much as
I consistently can in the physiological parts of these
lectures) I shall select some of the leading facts, and
draw such deductions from them as appear at once
the most obvious and are the best received. In the
course of our inquiry we shall find that the actions of
this organ are closely allied to the functions of re-
spiration, and that upon our knowledge of the latter will
often depend our ability to give an explanation of the
most important phenomena relative to the former. In
^'watching, in dying animals, the succession of contrac-
tions in the different cavities of this organ to their com-
plete cessation, it has been found that the right auricle
preserves its action longer than the left, from which
cii'cumstance Haller designated tliis part the ultimum
moriem ; and it has been ascertained by repeated ob-

On the Physiology of the Heart. 367

servation, that in cases of ordinary death the right side
of the heart is distended with blood, while the left
contains comparatively but little. Now, as an expla-
nation of these facts appears to be an indispensable
preparative towards unravelling the mystery of the
cause or causes of the heart's motion, physiologists
have spared no labor in searching for competent theo-
ries. Certainly, reasoning a priori, congestion on the
right side of the heart after death may be said to be
owing to its continuing to receive blood after the sup-
ply to the left has completely ceased ; but this only
amounts to speculative inference which it is incumbent
on us to show the stability of by additional facts be-
fore it can be admitted as a satisfactory explanation.
In my lecture "on the physiology of the lungs,'' I remarked
that the blood flowed uninterruptedly through them so
long as they continued in a state of expansion, but
that it met with impediment and occasional obstruction
whenever those organs were compressed : I may here
add, that this is fully confirmed by experiment, and
that the more perfect the collapse the greater is found
to be the impediment. Now, the last act of life being
a deep expiration, it follows that, as the blood is still
urged on from the arteries and poured by the venae
cavBB into the right auricle, whence it flows into the
right ventricle and pulmonary arteries, a congestion of
it in these vessels must eventually take place, in conse-
quence of its not finding its usual, ready passage
through the lungs ; whereas, with the left side of the
heart the reverse happens — those cavities can receive
but little blood, and that little they can get rid of so
long as their action is maintained. But, suppose

368 0?i the Physiology of the Heart.

that an animal breathed liis last by a deep inspiration ,
and that the lungs could be maintained in a state of in-
flation, what would be the result then ? If the impedi-
ment in the pulmonary circulation be the cause of these
appearances, and that impediment consist in collapse
of the lungs, the removal of it ought to be attended
with some alteration, if not a total change, in them.
The subjoined experiments of Professor Coleman's,
happily and ingeniously contrived, show that these
states of the right and left sides of the heart would
even be reversed if the animal died with an inspiration,
and very satisfactorily prove to us that compression and
probably complication of the pulmonary vessels are the
natural consequences of collapsed lungs*. And, not
only may the distention be transferred to the opposite
side, the continuance of action — the predominance of
vitality may be made to transmigrate from the right to
the left side, under certain unnatural circumstances ; so
that, in fact, the latter becomes then the veritable ulli-
mum moriens.

We must not rest here though ; by pursuing the in-
quiry we shall find that the action of the left side of
the heart may be interrupted, by a cessation of respira-

* " If a dog be hanged or drowned, the right side of the heart will
contain more blood than the left, in the proportion of about 28
to 15 in the former case, and of about 3J to 1| in the latter.
But, if the lungs be immediately, after apparent death, distended
with any innocuous fluid, such as water, to a sufficient degree to
remove the partial obstruction to the stream of blood through them,
the left side of the heart will contain more blood than the right in
the proportion of about J : if we suffocate the animal by putting
ligatures about the windpipe, the same phenomena are obsen'able."

Vide Coleman, o;i Suspe7ided Respiration.

On the Fhysiology of the Heart. 369

tion, in another way. If the lungs contain no air, or
air deficient of oxygen, it is evident that none of the
chemical phenomena I have so lately expounded can
take place : in short, what blood finds its way into the
left auricle will be blacker than that contained in the
right. And that blood can and does pass through
the lungs in a collapsed state. Dr. Goodwyn has proved,
in demonstrating, that sufficient air always remains in
these organs after death to admit of it ; a fact that led
this philosopher to conclude, that protracted expiration
was not fatal in the way commonly supposed, but (as
he imagined) arose from the left ventricle not being
stimulated by black blood, and the supply of the vari-
ous organs of the body being entirely suppressed.
There are several facts, however, that militate against
this opinion, and convince us that black blood can be
a stimulus to the left ventricle. If, for example, the
windpipe of an animal be tied and its carotid artery
opened, though red blood at first issue, black will be
ultimately ejected from it, and will continue to be
thrown out for a sufficient length of time to shew that
the left ventricle is acting on blood of a similar quality.
In cashes of suspended respiration also relieved by the
ordinary means, i. e. by inflation of the lungs, the
left ventricle must contract on black blood before it can
receive any duly changed from the pulmonaiy veins.
But in the fcstus (as will be explained when speaking
of its peculiarities) the left side of the heart is actu-
ally receiving darker blood than the right, and natu-
rally contracts upon it in the course of the ordinary
circulation.

I might go on in this way to combat the opinions of
others without being able to show after all why the
PART u. 2 B

370 Diseases of the Hedrt.

action of tlie heart ceases soon after the suspension of
respiration. Mechanical obstruction to the blood's
passage through the lungs, though it may tend to
weaken or retard the heart's action, does not appear
to be the immediate cause of its cessation, for so
long as the contractions of the right side are main-
tained, sufficient blood probably can still pass to the left
auricle to support life. It would appear rather to be the
want of a due change in the blood — the deficiency of
that which preserves the irritability or vitality of the
heart ; for it is admitted that, although the left side of
the heart is susceptible of excitement from black blood,
its action is weakened under such circumstances, and
can only be invigorated again by the blood receiving its
proper change. From a vast number and variety of
experiments, made with a view of throwing light upon
this interesting but abstruse subject, we are perhaps
warranted in drawing this general conclusion. That
the fibres of the heart, like those of other muscles, can
only be excited while possessed of irritability, and by
the application of certain stimuli, of which two appear
to be demonstrable : viz. that of distention, and that
dependant upon some unknown property of the blood
itself. Variations either in the degree of irritability, or
in the intensity of the stimulus applied to it, will cause
proportionate disturbance in its action, and the ab-
sence of one or both will arrest it altogether : in this
way alone can we account for the disordered actions of
this organ, either the direct effect of disease, or of
sympathy with that of other parts.

Diseases of the Heart.
In horses that die of pneumonia, the pericardium not

Diseases of the Heart. 371

infrequently participates in the diseased action. The
most common morbid aspect it has after death, is a par-
tial or general effusion of adhesive matter upon its
exterior, which may attach it to the pleurae, or to
the diaphragm, or to both. When first produced, this
adventitious covering is nothing more than common
albuminous matter infiltrated with serum, to which
it owes its bright yellow color ; but, if the case hap-
pen to run into the chronic stage and continue long
therein, it becomes organised, and assumes a variety
of appearances which I cannot devote space here to
particularize. There is generally more liquor pericardii
than in health in these cases, and the membrane itself
becomes, in some, preternaturally white, opaque, and
dense in its texture.

When inflammation attacks the secreting surface of
this membrane, it terminates, I believe, almost always
in hydrops pericardii. I recollect a case, at the Veteri-
nary College when I was a pupil there, in which death
happened suddenly and unexpectedly ; though it was
very satisfactorily accounted for on dissection by the
prodigious distention of the sac with fluid, which had
put a stop to the action of the heart. These horses
manifest no signs that lead us to the seat of their
malady — their disease is generally mistaken for pneu-
monia ; it is not a matter of much consequence how-
ever, for in a medical point of view I know of no dif-
ference in the general treatment.

The heart itself may be diseased either primarily or
secondarily — idiopathically or sympathetically.

The heart is said to be secondarily, symptomatically,
or sympathetically affected, when its pulsations vary
either in number or strength from those of an ordinary

2 B 2

372 Diseases of /he Heart.

state of health, in consequence of disease set up in
some other part of the body, however remote from the
organ itself. If eg, a horse in perfect health picks up
a nail, which pierces the sensible sole, and causes vio-
lent inflammation of the foot, what is called sympathe-
tic or symptomatic fever will ensue ; i. e. he will heave
more than common at the flanks, and his pulse, which
before the accident was forty-five, will rise to seventy,
eighty, or even ninety : here then the heart is diseased,
not in structure but in function, and the extreme pain
which the animal experiences in his punctured foot is
the cause of it. In such a case the heart is sympathe-
tically affected, I may say ner vously so ; for we cannot
explain it but by saying that this pain has excited
the nervous system and through' it the irritability of
this organ in particular. Its irritability being augment-
ed, it contracts upon a less quantity of blood ; indeed,
for aught we know, the blood itself may possess higher
stimulant properties ; in either case the same conse-
quences ensue — the heart may pulsate with increased
frequency and force, or be only irregular in one of these
particulars. And should this organ continue to act for
a length of time with extreme frequency, though with
diminished force, (for the two extremes are incompati-
ble,) should it beat forty times in a minute or twenty-
four hundred times in an hour more than it ought to do,
we are not to feel surprised that an animal should sink now
and then from exhaustion, induced by such excessive
and long-continued over-action of his vital functions.
But it occasionally happens that the heart labours under
a degree of torpor, and consequent slowness in its ac-
tion ; and this I believe in some individuals is natural,
I have myself remarked it in horses in apparent

Diseases of the Heart. 373

health, and Mr. Sewell had a horse under his care in
the College whose pulse never exceeded 20°, though
his constitutional health at the time was unaffected ;
most commonly however this is a pulse indicative of in-
flammation of the brain, we ought therefore to be on our
guard against it in staggers.

The heart is now and then primarily diseased. I have
met with some few cases of inflammation of it, (cardi-
tis) all of which, however, during life, were confounded
with pneumonia. Indeed, it but rarely happens that
the inflammation is confined to this organ or its mem-
branes : mostly the pleura partakes of it, if not the
lungs themselves. When inflammation does princi-
pally invade the heart, the surfacie (not the substance)
is mostly the part affected — its close pericardiac tunic
exhibits adventitious depositions of a variety of aspects,
though they all originate in the effusion of common
adhesive matter. I have seen this membrane con-
verted into a substance of the nature of cartilage, on some
occasions one-eighth of an inch in thickness. When
we meet with a strong, quick, and occasionally irregular
pulsation, unattended with so much embarrassment in
the respiration as denotes inflammation of the substance of
the lungs, and something like palpitations of the heart,
accompanied with the common febrile disturbance of
the system, we may suspect this organ to be the chief
seat of disease. I know of no difference of treatment
that carditis requires from pneumonia ; it is therefore
of little importance, as far as regards their distinction,
to know the diagnostic signs of either.

In the human subject the heart is liable to varieties
•in its natural conformation, and to some that produce
often the most unpleasant symptoms to the patient and

374

Diseases of' the Heart.

perplexing to the practitioner during life : of course they
do not admit of relief. I have not seen, nor heard of
any cases of the kind among horses. Angina pectoris,
syncope, palpitations, and some other cardiac affec-
tions, do not come within the sphere of veterinary
practice *.

* Mr. Henderson, V. S. London, is in possession of a remark-
ably fine specimen of ossification of the heart. The walls of the
right auricle are converted into bone, and consequently that cavity
must have been a passive receptacle for blood which must have
flown through it without impulse, or with very little, into the cor-
responding ventricle. The subject of this disease dropped down
dead, in an emaciated condition^ in a dust cart.

LECTURE XLI.

On the Mouth.

In commencing this lecture I may observe, that in
quadrupeds the facial angle is one, generally speaking,
of very considerable obliquity, in consequence of the
prolongation of the face ; a feature none possess more
strikingly than the horse and the dog. In these ani-
mals, consequently, the nose and the mouth are cavities
of large dimensions ; and the latter appears to have been
so consti'ucted, not only to enable the horse to collect
his food with more facility, but to enable him to sub-
ject greater portions of it at one time to the action of the
grinding teeth, whereby the processes of mastication
and deglutition are greatly accelerated.

The mouth is composed in part of bone, and in part
of soft material : the ossa maxillaria superiora et inferi-
ora, the ossa palati, the maxilla posterior, and the teeth,
constitute its bony parietes ; the lips, cheeks, palate,
gums, tongue, membrane of the mouth, and salivary
glands, its soft parts. It will not be necessary to de-
scribe again the situation and connexions of these bones ;
though I may remark here, that unless these particula-
rities be known, I shall not be well followed in the
description I am about to give of the other parts.

376

Lips.

The lips, two in number, anterior and posterior,
arise from the alveolar processes of the jaws, to which
they are attached by the muscles that move them, by
the cellular substance composing them, and by the
membrane that lines them : their united borders form
the angles of the mouth, or commissures of the lips. Ex-
ternally they are marked by a medium line of division,
have little eminences upon their surface, and present a
different coating of hair from what is found in other
parts, from which here and there project long whiskers or
horse-hairs ; which hairs in the posterior lip constitute
the beard. The posterior lip is smaller and thinner in
substance than the anterior, and the place from which
the beard grows is distinguished by a very remarkable
prominence of it.

The lips may be said to be both muscular and glandu-
lar in their composition. Several small muscles, (which
have already come under our observation *,) arising from
the maxillary bones, are inserted into them, and endow
them with great self-mobility ; one alone, consisting of
circular fibres, is interwoven in their substance with-
out having any other connexion ; this is denominated
the orbicularis oris, or sphincter labiorum from its use,
which is that of closing the mouth. This muscle is an
antagonist to all the others : they raise or depress the
lips, or draw them to one side ; but this contracts them,
and occasionally projects them in such a manner that the
horse can exert with them a prehensile power, which is
most remarkable at the time that he is picking up grain

* Vide Lecture xxvii. Facia„ Rfgion.

Cheeks. — Gums. — Palate.

377

from a plain surface ; indeed the act of nibbling our hands
with his lips demonstrates this faculty, and also the
force with which he can employ it. The lips are lined
by the membrane of the mouth, beneath which there are
numerous mucous follicles that elevate it everywhere into
little papilla, which are perforated by the mouths of
these glands, and may be readily seen with the naked
eye by everting either the anterior or the posterior lip.
The skin covering the lips is extremely thin, and pos-
sesses considerable vascularity and sensibility: to the
fineness of this tegument, and to the shortness and scan-
tiness of their pilous clothing, I would ascribe their su-
perior sensitive faculty.

Cheeks.

The cheeks are chiefly constituted of the masseter
and buccinator muscles ; they are, in fact, fleshy parts,
covered by the common integument and lined by the
membrane of the mouth, studded inwardly with some
scattered mucous glands, whose excretory openings be-
come apparent within the mouth when the membrane
lining them can be brought into view.

Gums.

The gums consist of a dense, compact substance, of
the nature of periosteum, which adheres so firmly to the
teeth, and to the alveolar processes of the jaws, that it
renders the two inseparable but by great mechanical
force. Like the other parts of this cavity, the gums are
invested by the membrane of the mouth.

Palate.

The palate is divisible into two ports : — the hard -And

378

Palate.

the soft palate, Tlie hard palate is constituted of the pa-
latine procesiies of the ossa maxiliaria superiora et infei iora,
and of a firm, dense, periosteum-like substance, the
vaulted, inward part of which is elevated into several se-
micircular ridges, vulgarly called the bars. The fibres
of this substance, which possess great strength, penetrate
the pores of these bones in every part, but are most nume-
rous and distinct along the palatine suture ; and their in-
terstices are filled up by a dense cellular membrane,
through which are dispersed the ramifications of the pala-
tine vessels and nerves.

The soft palate, sometimes called the velum palati, is
attached to the superior, crescentic border of the hard pa-
late, which border is formed by the palatine bones; from
this the velum extends backward and downward as far
as the larynx, and there terminates above the epiglottis,
in close apposition with that part, in a loose semicircular
border. In consequence of the velum palati being long
enough to meet the epiglottis, the cavity of the mouth
has rio communication with that of the nose — these parts
forma perfect septum between them; hence it is that a
horse cannot respire and vomit by the mouth like a hu-
man being, in whom the velum is so short that there is
an open space left between it and the epiglottis, through
which air or aliment can pass either upward or down-
ward. The soft palate is composed of extensions of
membrane from the nose and mouth, between which is
interposed a pale, thin layer of muscular fibres, formed by
the union of two small muscles proper to this part. The
first muscle is the

Levator palati, which proceeds from the pars petrosa
of the OS temporis, adhering in its course to the eusta-
chian tube, and is dispersed and lost upon the velum.

Tongue. 379

It will raise the velum in the act of deglutition, and pre-
vent the escape of food or water into the nose.

Tensor palati makes up the chief part of the muscular
substance of the palate. It adheres to that crescentic rim
of bone which is formed by the ossa palati. In action,
it will stretch and tighten the velum, and render it capable
of resistance.

The velum then performs the office of a valve ; it pre-
vents the food in the act of swallowing from passing into
the nose, and it conducts the air from the windpipe into
that cavity, without permitting any to escape into the
mouth.

Tongue.

The tongue, the principal organ of taste and of deglu-
tition, is a muscular body lying within the cavity of the
month.

Like the other organs of sense it is double ; being com-
posed of two parts, whose union is marked by a longi-
tudinal furrow along its middle, that have no vascular nor
nervous connexion, nor in fact any intercommunication
whatsoever: so that an animal has to all intents and pur-
poses two tongues, and apparently for the same reason
that he has two eyes, two ears, and two nostrils. Ana-
tomy, as far as we can carry our researches, demon-
strates this; perhaps we have no better proof of it how-
ever than what happens in hemiplegia, a disease in which
only one half of the body is paralytic ; under these cir-
cumstances, in the human subject, the patient can only
see with one eye, use one arm, and taste with but one,
and that the correspondent side of the tongue.

The tongue, in description, is commonly divided into
root, body, and apex: by the attachments of the two

380 Tongue.

former it is held in its situation; the latter is loose and
unconnected. At its root, it is deeply and firmly at-
tached by several muscles which arise chiefly from the os
hyoides and the maxilla posterior ; it is also connected
with the pharynx, and with the soft palate. From the
sides of the lower jaw, separate layers of the membrane
of the mouth are reflected upon its body, where tiiey
form by their junction a sort of bridle, which is thence
extended to the symphysis : to this part, which serves to
restrain the organ in its motions, the name of ficcmim lin-
gua has been given.

The dorsum or anterior part of this organ, has a peculiar
covering : though this appears to be continued from the
same membrane, it is a different structure altogether, and
serves quite a difi"erent purpose. The surface of it is rough-
ened by a villous texture, and this is everywhere studded
with numerous little conical eminences, called papillts,
which are supposed to be formed chiefly of the extremities
of nerves, and to be the especial seat of the sense of taste.
These papilla; vary in size and figure, and are more
abundant and larger upon the base and along the sides of
the organ. Interspersed with them are a number of mu-
cous follicles, whose apertures may be seen with the
naked eye, through which a mucus is discharged upon
the papillary surface that keeps it continually moist, and
renders its perception of taste more acute.

The tongue is said to derive a covering from the com-
mon integuments ; and certainly its strong compact
tunic has all the appearances of skin, and presents the
common tests of it : the external layer is laminated, isblood-
less, is insensible ; the internal or substantial part is tough,
fibrous, vascular, and sensitive, in fact, is like cutis ; and
the intermediate or connecting material is weak, soft, and

Salimry Glands. 38 1

reticular, and forms a bed for the lodgement of the
papillae. The substance of the tongue itself consists of
an interunion, or an incorporation of its muscles, the
fibres of which intersect one another and take a variety of
directions ; but intermixed with them is a iine adipose
tissue to which is owing the flabby softness of this organ,
and the peculiar aspect it exhibits when cut into.

Though the tongue is emphatically denominated, from
its essential character, the organ of taste, it is not the
only part that possesses this faculty ; for the palate,
pharynx, and esophagus, it is believed, participate in it.
The tongue also disposes of the food during manduca-
tion, and, when it is sufficiently masticated, collects and
thrusts it, portion after portion, into the pharynx : more-
over, when the animal drinks it is not only employed as an
instrument of suction, but as a canal along which the
fluid ascends into the pharynx.

Every part of this organ is plentifully supplied with
blood. Its arteries are the lingual, branches of large
size from the external carotids. The blood-vessels of
either side are generally found free from anastomosis
with one another : if either of the arterial trunks is filled
with injection, it rarely happens that the opposite half
of the organ receives any coloring from it. Its nerves
are the ninth pair, which run to the muscles, and a con-
siderable branch from the fifth pair; and it is in the ex-
treme terminations of the ramifications of the latter,
which are distributed to the papilize, that the perception
I of taste is supposed to be inherent.

Salivary Glands.

The salivary glands, properly so called, are six in
I number, three upon each side of the head : — the parotid,
I the submaxillary, and the sublingual.

382 Salivary Glands.

The parotid, the largest of these glands, so called
from being placed near the ear, lies within a hollow
space at the upper and back part of ihe head, bounded
by the branch of the lower jaw before, and the petrous
portion of the temporal bone behind ; it extends as high
up as the root of the ear, and as low down as the angle
of the jaw by which a small portion of it is concealed*
This gland, like the others of the same class, is enveloped
in a dense cellular membrane, and is constituted of many
little lobes or lobuli, connected together by processes
transmitted into the interior from its cellular covering.
Every lobulus is composed of a distinct set of secretory
vessels, from which numerous tubuli arise, conjoin, and at
length form one main branch ; these branches, which
correspond in number to the lobuli, unite and re-unite
until they end in one common excretory duct. The
duct emerges from the inferior part of the gland, runs
along the inward part of the angle of the jaw, and crosses
over the posterior edge of the bone immediately above
or behind the submaxillary artery and vein ; in the re-
mainder of its course it corresponds to the border of
the masseter, and about opposite to the second anterior
molar tooth, pierces obliquely the buccinator, and ter-
minates by a tubercular eminence upon the inwaid sur-
face of the membrane of the mouth.

The submaxillary gland, of smaller size than the
parotid, lies between the angles of the jaw, to which,
and to the muscles thereabouts, it is loosely attached
by cellular membrane : a portion of it is also gene-
rally found proceeding backward as far as the tra-
chea. Its structure is similar to that of the parotid
gland. The submaxillary duct begins near the centre of
the gland, runs along the under and inner border of the
tongue, close to the lower edge of the sublingual gland,

Oh the P/unynx. 383

and terminates, by a little nianimi-form prolongation of
membrane, vulgarly called the barb (barbillon) or pap,
upon the fraenum linguae, about half-an-incli above its
attachment to the symphysis. Among the other ridicu-
lous and mischievous practices of farriers is that of
snipping off these processes. They were seemingly de-
signed as valves, to prevent the insinuation of alimentary
matters into the ducts. The coats of this vessel are
extremely thin and translucent.

The sublingual gland is still smaller than the submax-
illary, though altogether one much resembles the other
in figure. It lies along the under part of the tongue,
covered by the membrane of that organ, where, from the
lobular unevenness it gives to the surface, its situation
is well marked. Its ducts penetrate the membrane of
the mouth by the side of the fraenum lingus.

The use of the salivary glands is to secrete a saline,
limpid fluid, called saliva ; and this is conveyed and
poured by their ducts into the mouth during manduca-
tion ; here it is mixed with the food which it molli-
fies and renders more easy of digestion, and at the same
time facilitates the passage of the alimentary bolus ijito
the stomach.

On the Pharynx.

The pharynx is a muscular bag of a funnel-like shape,
formed at the root of the tongue, and lined by the mem-
brane of the mouth.

It is attached to the sides of the os hyoides, to the
bones forming the palate, and tO the larynx ; as it pro-
ceeds backward it grows narrow, contracts, and ends in
the esophagus.

The pharynx is composed of three pairs of muscles,
called the constrictores pharyngis, the description of which

384 On the Pharynx.

I have purposely reserved for this place, in order that
the structure and attachments of the bag might be better
understood.

Constrictor pharyngis superior, with its fellow of
the other side, constitutes the first pair. It arises from
the base of the os hyoides, near to the thyroid cartilage.
Hence it runs- backward, broadens in its course, and
is inserted, through the intervention of a tendinous line
which here unites it with its fellow, along the posterior
and middle parts of the pharynx.

Constrictor pharyngis medius runs below the former,
than which it is larger. It takes its origin from the thy-
roid cartilage, behind the attachment of the thyro-hyoi-
deus, pursues a like course to the former, meets its
fellow upon the posterior part of the pharynx, and is
fixed to the tendinous intersection there.

Constrictor pharyngis inferior is to be found still
lower. It arises from the posterior part of the cricoid
cartilage, whence it passes obliquely upward, forms an
inseparable union with the constrictor medius, and is
inserted, with its fellow, into the lowermost part of the
pharynx, where it joins the esophagus. Their use, as
their name implies, is to constrict or contract this cavity
during deglutition.

These muscles, the proximate fibres of which are conti-
nued into one another and blended together, form the mus-
cular or most substantial part of the pharynx. They are
lined by a mucous membrane, which is thick, soft, in
places rugose, slightly reddened, and continuous with
the linings of the mouth, esophagus, and larynx : it is
perforated by the ducts of many follicles which keep its
surface moist and slippery by their discharge of mucus.

In the horse, this musculo-membrauous sac is parti-
tioned from the cavity of the mouth by the soft palate

On the Esophagus. 385

and epiglottis. The mouth is bounded above by the
fauces, and except in the acts of swallowing and cough-
ing has no communication with tiie pharynx : in the
former case, the velum is pressed upward by the food
against the posterior openings of the nose ; in the latter,
the larynx is depressed by a convulsive action of the
muscles in the vicinity. Into the cavity above the velum
then there are four openmgs : — two of the chambers of
the nose, one of the larynx, and one of the esopha-
gus : the eustachian tubes do not open into the pharynx,
they end in two large membranous sacs at the upper part
of the fauces. The opening leading into the esophagus
is constantly closed, except when alimentary matters are
passing to or from the stomach ; so that air received into
the pharynx through the nose can pass nowhere else but
into the windpipe ; but if food be returned from the sto-
mach, it will be regurgitated into the nose ; at least, only
that portion of it which enters the pharynx at the mo-
ment that the larynx is depressed in the act of vomiting,
can be thrown into the mouth : in the same way that air
is in the act of coughing.

On the Esophagus.

The esophagus or gullet is a muscular tube, formed
for the purpose of transmitting food from the pharynx
into the stomach.

It has its origin from the pharynx, and is there placed
at the upper and back part of the larynx, taking the first
part of its course above and behind the windpipe, between
that tube and the cervical vertebree. Having proceeded a
short way down, it inclines to the left, and soon after
makes its appearance altogether on the left side of the
windpipe, and continues so placed during the remainder

PART II. 2 c

I

386 On the Esophagus.

of its passage down the neck : this explains why we look
for the bolus during the act of swallowing on the left,
and not on the right side of the animal. In company
with the trachea the esophagus enters the chest between
the first two ribs, and there, running above that tube,
quits it for the superior mediastinum, which cavity it
traverses below and a little to the right of the aorta pos-
terior. Immediately below the decussation of the
crura the esophagus pierces the substance of the dia-
phragm, and enters the stomach, at a right angle, about
the centre of its upper and anterior part.

The esophagus presents externally a strong, red,
muscular coat ; internally, one remarkable for its white-
ness, which in its nature is cuticular. The muscular
coat is composed of two orders of fibres : — a longitudi-
nal forming an outward layer, and a circular an inward
layer: the former will shorten the tube, and perhaps
dilate it for the reception of food ; the latter, by succes-
sive contractions of the canal, will transmit the food
into the stomach. The second, or internal coat, is
called the cuticular from its analogy to the cuticle of
the skin ; though it is continuous with the membrane of
the pharynx, it is of a totally different composition ; it is
thinner, but it is much more compact and stronger in
its texture, and, I believe, is both insensible and inor-
ganic. It adheres to the muscular covering by a fine
cellular tissue, the extensibility of which gives full
play to the latter ; and during the empty or collapsed state
of the tube is thrown into many longitudinal plic& or
folds ; or, if a transverse section is made of the tube,
projects in folds from its divided ends : both which ap-
pearances result from the contraction of the one coat,
and the want of adequate elasticity in the other. Be-

Diseases of the Mouth. 387

tweeii this and the external coat, embedded in the in-
terposed cellular tissue, are numerous mucous follicles,
which pour forth their secretion upon the internal sur-
face to lubricate it, and thus afford a gliding passage
to the manducated mass into the stomach.

Diseases of the Mouth.

The membrane of the mouth may be excoriated, •
lacerated, or otherwise injured in a variety of ways.
The repeated contusions made by the pressure of the
port of a sharp curb-bit will, now and then, be followed
by deep exulceration of the posterior jaw, sometimes of
the palate, and even carries of the bones themselves.

Another, and not a very uncommon accident, is lace-
ration of the frsenum linguae ; which is occasioned by
forcibly drawing the tongue out and pressing it against
tlie edges of the molar teeth, in the act of giving a ball.
But the substance of the tongue may be injured — bitten
by the horse himself, which I suspect generally hap-
pens during sleep ; at least, I saw a case of this de-
scription some time ago, in which the tip of the organ,
to the extent of about four inches, was nearly severed
from the body, that took place during the night ; and
this was the only explanation that appeared feasible at
the time. Here it was found necessary to employ
sutures.

Ulceration of the cheeks also may take place ; and
when it does I believe it to be the result of some abra-
sion of surface, either in consequence of the edges of
the molar teeth becoming sharp from irregular wear, as
they do now and then in old horses, or from the irri-
ition of a sharp twisted snaffle, or perhaps from some

2 c 2

388 Diseases of the Mouth.

prickly or other mechanically noxious substance taken
in and masticated with the food.

Horses having one or other of these affections froth
at the mouth from an increased secretion of saliva, cud
their food, and often refuse to eat any but what is of a
soft and easily-masticated nature. These symp-
toms lead us to examine the mouth, where we seldom
fail to discover the source of the evil.

We need not trouble ourselves much about remedies
for these accidents ; if the cause be removed there is little
doubt but the sores will heal. Should the jaw or roof of
the mouth have been exulcerated by a curb-bit, a snaffle
or Pelham bit ought to be worn until the injury shall have
been repaired. If there is any appearance of necrosis,
the nitric acid lotion — about ten drops to the ounce of
water, will, used with discretion, prove of great service :
as soon as the dead bone has come away, tincture of
myrrh or the alum wash * may accelerate the granulating
process. But we must not be too inter-meddling here :
there is often much harm done in these cases by the
over-doing, officious practitioner. When the freenum
linguae or the tongue itself is lacerated, the main object
in the treatment — and a troublesome one it is, is to keep
the wound clear from the manducated matters, which
are (especially hay) continually lodging there ; and with
this view I would lay any pouch or sinus open that was
found in it with a bistoury. In regard to dressings,
none are in general required ; but, if we are compelled
or determined to do something, we may wash the parts

♦ R Alum. Pulv. 3j.
Aq. turae Ibj.

M. ft. Lotio. injicienda ter quaten'e die.

Lampass. 389

frequently in the course of the day with a strong solu-
tion of alum, or some other astringent application. If
the teeth offend, from having worn sharp or irregular,
they may be filed smooth ; and as for the excoriations
they have occasioned, they will get well of themselves.

Lampass.

The lampass is a name given by writers on farriery
to a swelling or an unnatural prominence of some of
the lowermost ridges or bars of the palate. I should
not have thought it worth while to have taken up time
with this supposed malady, but that it has called forth
the infliction of great torture on the animal by way of
remedy, and that it has been a cloak for the practice of
much imposition on those who have been in the habit of
consulting farriers on the diseases of their horses. I al-
lude to the cruelty and barbarity of burning the palates
of horses so affected ; equally consistent would it be, and,
were it consistent, more requisite, to cauterize the palates
of children who are teething ; for, the truth is that the
palate has no more to do with the existing disease (if
disease it can be called) than the tail has. Lampass is
neither more nor less than a turgidity of the vessels of
the palate consequent upon that inflammatory condition
of the gums which now and then attends the teething
process ; but, notwithstanding this plain and simple
truth, the animal (and I believe this is owing to its not
having been explained before) continues to be perse-
cuted for it— even by some professional men as well as
farriers, up to this very hour. The practice is a stigma
upon our national character, and a disgrace to the pro-
fessors of veterinary science.

Teething in children indeed is now and then a season

388 JDkeases of the Mouth.

prickly or other mechanically noxious substance taken
in and masticated with the food.

Horses having one or other of these affections froth
at the mouth from an increased secretion of saliva, cud
their food, and often refuse to eat any but what is of a
soft and easily-masticated nature. These symp-
toms lead us to examine the mouth, where we seldom
fail to discover the source of the evil.

We need not trouble ourselves much about remedies
for these accidents ; if the cause be removed there is little
doubt but the sores will heal. Should the jaw or roof of
the mouth have been exulcerated by a curb-bit, a snaffle
or Pelham bit ought to be worn until the injury shall have
been repaii*ed. If there is any appearance of necrosis,
the nitric acid lotion — about ten drops to the ounce of
water, will, used with discretion, prove of great service :
as soon as the dead bone has come away, tincture of
myrrh or the alum wash * may accelerate the granulating
process. But we must not be too inter-meddling here :
there is often much harm done in these cases by the
over-doing, officious practitioner. When the freenUm
linguae or the tongue itself is lacerated, the main object
in the treatment — and a troublesome one it is, is to keep
the wound clear from the manducated matters, which
are (especially hay) continually lodging there ; and with
this view I would lay any pouch or sinus open that was
found in it with a bistoury. In regard to dressings,
none are in general required ; but, if we are compelled
or determined to do something, we may wash the parts

* R Alum. Pulv. 3j.
Aq. Purae tbj.

M. ft. Lotio. Injicienda ter quatcrvc die.

Lampass. 38 J

frequently in the course of the day with a strong solu-
tion of alum, or some other astringent application. If
the teeth offend, from having worn sharp or irregular,
they may be filed smooth ; and as for the excoriations
they have occasioned, they will get well of themselves.

Lampass.

The lampass is a name given by writers on farriery
to a swelling or an unnatural prominence of some of
the lowermost ridges or bars of the palate. I should
not have thought it worth while to have taken up time
with this supposed malady, but that it has called forth
the infliction of great torture on the animal by way of
remedy, and that it has been a cloak for the practice of
much imposition on those who have been in the habit of
consulting farriers on the diseases of their horses. I al-
lude to the cruelty and barbarity of burning the palates
of horses so affected ; equally consistent would it be, and,
were it consistent, more requisite, to cauterize the palates
of children who are teething ; for, the truth is that the
palate has no more to do with the existing disease (if
disease it can be called) than the tail has. Lampass is
neither more nor less than a turgidity of the vessels of
the palate consequent upon that inflammatory condition
of the gums which now and then attends the teething
process ; but, notwithstanding this plain and simple
truth, the animal (and I believe this is owing to its not
having been explained before) continues to be perse-
cuted for it — even by some professiojial men as well as
farriers, up to this very hour. The practice is a stigma
upon our national character, and a disgrace to the pro-
fessors of veterinary science.

Teething in children indeed is now and then a season

390

Tjampass.

of restlessness and i>ain, and was one, before surgeons
were in the habit of using the gum-lancet, of anxiety
and danger ; but it is not so with horses ; they never
have any feverish irritation created in the system,
though they have some tenderness of the gums and
palate, and though some few, in consequence of this
tenderness, cud their food or refuse to eat any but
what is soft and unirritating. In such a case, if any
thing requires to be done, we ought to lance the gums
— not the palate ; but I do not remember ever to have
had occasion to do this but once *. The inutility of
lotions or in fact any external or internal medicament,

* About three years ago I was requested to give my opinion of
a horse, then in his fifth year, who had fed so sparingly for the
last fortnight, and so rapidly declined in condition in consequence
of it, that his owner, a veterinary surgeon, was under no light
apprehensions about his life. lie had himself repeatedly examined
his moutli without having discovered any defect or disease, but
another veterinary surgeon to whom he had shown the animal was of
opinion that the averseness or inability manifested in masticating
food, and the consequent cudding of most of that taken in, arose
from 3 preternatural bluntness of the faces of the molares ; these
teetli therefore were filed, but no benefit resulted. It was
after this that I saw the horse; and I confess that I was just as
much at a loss in my first examination to offer any thing satisfac-
tory on the case as many others who were then present ; for his
teeth and mouth altogether appeared to us all to be perfect and
healthy. As I was ruminating however after my inspection on
the apparently extraordinary nature of the case, it struck me
that I had not seen the tusks. I immediately betook myself to a
re-examination, and then discovered two little tumors, red and
hard, in the situations of the posterior tusks, which, when pressed,
appeared to give the animal insufferable pain. I instantly took a
pocket knife and made crucial incisions through these prominences
down to the teeth, from which time the horse recovered his appetiffc
and was restored.

Stricture of t/ie Esophagus. 391

will sufficiently appear without any comment here ; I
need not therefore extend this unimportant subject.

Stricture of the Esophagus.

In the Veterinary Museum belonging to the Riding
House Establishment at Woolwich, is an elegant pre-
paration of this disease. I have not been able to col-
lect any more particulars of the case than those con-
tained in the following short memorandum, which I
have transcribed from the book of reference to the pre-
parations.

No. 26. — " Shews a portion of stomach taken from a
horse that had (during life) some apparent difficulty to
swallow his food. The animal became so much re-
duced in condition that it was thought advisable to de-
stroy him. On dissection, the esophagus, at its en-
trance into the stomach, was found almost impervious
from stricture."

LECTURK XLII.

On the Viscera of the Abdomen.

1 HE abdomen or belly is mostly formed of soft parts,
and tliey consist pi'incipally of the four pairs of abdominal
muscles, the situation and attachments of which I have
already described. Its anterior part, where the most
important viscera lie — such as the stomach and liver, is
bounded by the false ribs laterally, and in front by
the diaphragm ; its posterior, containing the organs of
generation, by the pelvis ; and its superior, by the dor-
sal and lumbar vertebrae, and by the muscles of the
loins.

Before I take a view of the interior of the abdomen,
it will be necessary to point out those compartments or
regions into which anatomists have divided it, by draw-
ing certain imaginary lines over its superficies, from
which extend so many imaginary planes through tlie
cavity ; for had not some such division of it been made,
our description of the particular situation of the different
viscera within, or of any wound inflicted in its panetes,
must have been confused and often unintefligible. The
first or grand division of the abdomen is into three re-
gions. The anterior or epigastric region is the space
comprehended between the ensiform cartilage and a

Peritoneum,

393

line dravvu across tlie belly, posteriorly to the cartilages
of the false ribs ; it is subdivided into three others
the scrobiculus cordis, the space included between the
libs ; and the right and left hypochondria, the lateral car
vities or boundaries of it. The middle or umbilical
region extends in breadth from the line just mentioned
to another drawn from one anterior spinous process of
the ileum to the other : it is equally subdivided into three
others by transverse lines, the middle of which retains
the name of umbilical region, while the lateral are called
the lumbar regions. The posterior or hypogastric region
extends over the remainder of the belly. It is also sub-
divided into three : — the part included between the spi-
nous processes of the ilea and the pubes, receives the
name of regio pubis ; the lateral subdivisions, of iliac
regions.

The abdominal viscera of the horse differ from those
of the human subject chiefly in the shape and compa-
rative size of the stomach and colon : their general re-
lative situation we shall find to be much tlie same in
both.

Haviug opened the abdomen, by making a crucial in-
cision through it3 muscular parietes, we perceive that
the interior of the cavity and the viscera lying in it, pre-
sent an uniform glistening surface, ar§ smooth, humid,
and slippery to the feel, and are bedewed with a limpid
hquor ; all which arises from a geperal investing nxem-
braiie that is of the same (serous) class as the pleura,
and appears, in most respects, to perform similar uses :
to tliis part the name of peritoneu^m has been given.

Peritoneum.

TuE peritoneum is a membrane then that lines the ca-

394

Peritoneum.

vity of the abdomen, and is reflected upon the contained
viscera. If I introduce my hand into the belly, eveiy
surface I apply it to being covered by peritoneum, I am
not, in truth, able to touch any of the viscera within it :
this, we know, is precisely what happens in regard to
the pleura.

The texture of this membrane also is like that of the
pleura. If I strip it off from any part, I find it rough and
shaggy exteriorly, from the presence of numerous little
flocculent adhesions ; and this shews the nature of its
attachment to the several parts it invests ; viz. by cellu-
lar tissue. But its interior surface is every where
smooth, humid, and slippery, and this is assignable to
two causes — to the uniformity and compactness of its
texture, and to the exhalation of a serous vapor, which
after death becomes condensed, and which we always
find more or less of, in the liquid state, between the
different viscera. The peritoneum appears to be com-
posed of condensed cellular membrane, interwoven with
numerous blood-vessels, some nerves, and many absorb-
ents. It is extremely elastic, whereby it accommodates
itself, without corrugation, to the perpetually varying ca-
pacity of this cavity and the frequent change of volume
and relative situation of many of the viscera : indeed, at
certain times, it must admit of very considerable exten-
sion ; e. g. in the mare during gestation, and in ascites.

What are called the ligaments of the peritoneum, are
certain parts which in the foetus were vessels of import-
ance, but which in the adult degenerate into impervious
cords, and for this reason have their name altered.
The anterior ligament or ligamentum rotundum, origi-
nally the umbilical vein, runs between the peritoneum
and abdominal muscles, from the umbilicus or navel to

Situation of the Viscera of the Abdomen. 395

the liver. The two posteiior ligaments, consisting- of
what once were the umbilical arteries and the urachus,
pass in the same manner from the navel to the bladder ;
the former traversing its sides to join the iliac arteries,
the latter entering the bladder at the very apex of its
fundus. In the young animal it generally happens that
these vessels are pervious for a considerable distance,
but their calibre is exceedingly reduced in size, and
their coats proportionately thickened.

The principal use of the peritoneum is to furnish a
serous fluid — a fluid that exists in a vaporous state
during life, for the lubrication of every part of the mem-
brane ; in consequence of which those viscera that are
continually moving within the belly, glide over one
another not only without friction, but without the least
consciousness of their motions on the part of the animal
himself. In addition to this, the peritoneum furnishes
most of the viscera with a complete external tunic, and
thereby adds strength and firmness to their several tex-
tures ; it attaches, and thus supports, and confines
those viscera within certain limits, in their respective
places ; and it strengthens the cavity altogether by its
uninterrupted extension through and around it.

I shall not speak of the reflections of this membrane
until I have pointed out the situation of the different
viscera.

Situation oftJie Viscera of the Abdomen.

When the cavity of the belly is laid open, the large
intestines first present themselves to view ; consequently
they are placed undermost when the animal is standing,
and are immediately lying upon the abdominal muscles.
About the middle of the exposed cavity, the apex of the

396 Situalion of the Viscera of the Abdomen.

ccecum protrudes from the body of that gut, which is ex-
tended to the right side, encircled by the colon. Generally
speaking, the small intestines are not seen on first re-
flecting the muscles ; this however will depend on the
state of the large, for if they be flaccid some of the small
guts will insinuate themselves between the ccecum and
colon : should we not see them however in th.e first in-
stance, they may at once be brought into view by turn-
ing the ccecum to the right side.

The STOMACH is principally lodged in the lefthypo-
ch-ondriac region, though a part of it extends into the
epigastric and there crosses the spine. Its anterior or
convex part lies against the diaphragm, and the false
ribs of the left side ; its posterior or concave part is
concealed by the intestines ; its lower surface is invested
by omentum ; its left extremity has the spleen attached
to it, which viscus also extends along its great curvature ;
quad its right is in contact with the left and middle lobes
of the liver.

Before I proceed to describe the situation and course
of the intestines, it is necessary to observe, that anato-
mists have divided them into the small and large ; and
that the first, beginning from the stomach, comprehend
three subdivisions — the duodenum, jejunum, and ileum ;
and that the latter, commencing from the termination of
the small, are also subdivided into three — the coecum,
colon, and rectum.

From the right extremity of the stomach arises
the DUODENUM, which soon after its origin forms a
cuvvatuie around the head of the pancreas ; having the
liver above, and the great arch of the colon below it.
Having reached the concave part of the liver, it makes
a sudden turn backvk'ard and to the right, and becomes

Situation of the Viscera of the Abdomen. 397

attached to the right kidney ; it then crosses the spine,
between the roots of the mesentery and mesocolon, to
the left side, where it takes the name of jejunum. This
gut, during its course, is so closely bound down by
peritoneum, that its motions mustbe exceedingly limited ;
so that it will always bear pretty nearly the same rela-
tive situation in regard to those viscera whose motions
are confined — the stomach, the liver, and the kidney.

The JEJUNUM and ileum, which do not essentially
differ from each other, except that the latter is one-fifth
longer than the former, constitute together numerous
convolutions, which are lodged principally in the umbili-
cal region, where they are encircled and in part con-
cealed by the colon. They are but loosely connected to
the spine by peritoneum ; so that, unlike the duodenum
whose attachments are very short, they can move in
various directions and to a considerable extent : a cir-
cumstance, of course, that will materially affect their
relative situation.

The ileum, towards the right side of the cavity, ter-
minates in a part of the large intestines, which, from its
continuity with the colon, to which and to the coecum
it appeai-s to give origin, has been denominated the ca-
cum caput coli, or blind head of the colon. From this
part proceeds downward the body of the ccecum, and
thence its apex protrudes, in the manner I have already
described, amid the convolutions of the colon.

The COLON, taking its origin from the same part
where the ccecum begins, at first passes downward, and
encircles the body of the coecumj running both before
and behind that gut ; then it reflects upon itself, and
makes a second turn like the first ; so that this part,
which may be called its great arch, is double. That

398 Situution of the Viscera of the Abdomen.

portion of the second flexure of the gut which forms the
upper and anterior part of the arch, and which fills up
the bottom of that space between the cartilages of the
false ribs, is of very considerable bulk ; in its course,
however, to the left side of the spine, it becomes again
contracted, and is there attached to the spleen, with
which it runs in contact. Under the left kidney it
makes a sudden curve backward, and becomes reflected
upon itself somewhat like the letter S ; from which pe-
culiarity of figure, this part is called the sigmoid flexure
of the colon. It is worthy of remark here, that, although
the colon and ccecum are intestines that possess
considerable motion, they are so united that they cannot
alter their places materially in regard to each other :
I may add alfeo, that they will invariably occupy the
lowermost parts of the abdominal cavity.

As soon as the colon has reached the basis of the
sacrum, it takes the name of rectum ; the remaining
portion of gut, however, so called, is not perfectly
straight, but follows the bend of that bone. It termi-
nates by an enlarged extremity in the anus.

The OMENTUM (the intestines being drawn to one
side) is now brought into view, investing the lower part
of the stomach ; to the great curvature of which, and
to that portion of colon which crosses the spine to form
the segmoid flexure, (its last turn,) it is attached. In
the horse, the omentum is small, and seldom contains
much adipose matter. It consists of four layers of pe-
ritoneum : two derived from the stomach, and two from
the colon ; which are disposed in a manner I shall point
out when I come to speak of the reflection of that mem-
brane.

The small intestines are loosely connected to the spine

Situation of the Viscera of the Abdomen. 399

by a duplicature of peritoneum, called the mesentery;
the colon is attached in like manner to it by a produc-
tion of the same membrane, named the mesocolon ;
and the rectum is confined in its place by a similar re-
flection, by some described as the mesorectum.

The liver is mostly placed in the left hypochondriac
region, though some part of it lies in the epigastric,
and a small portion extends between the stomach and
diaphragm into the left hypochondrium. This viscus
is confined in its situation by means of, what are named,
its ligaments; which, with the exception of one, are
nothing more than productions of peritoneum. The
one attaching the right lobe to the diaphragm, is called
the right ligament ; a similar one connecting the left to
it, the left ligament: between the diaphragm and its
middle lobe, we find the suspensary ligament ; and im-
mediately above that, surrounding the vena cava pos-
terior, the coronary ligament ; lastly, within the folds
of the suspensary ligament are the remains of the um-
bilical vein, to which the name of round ligament has
been given. The large lobe of this gland is concealed
by the great arch of the colon ; its left and middle lobes
are in contact with the stomach, and its right with the
duodenum and upper margin of the right kidney ; to
all of which it has peritoneal attachments.

The SPLEEN is situated in the left hypochondriac re-
gion, lying there within the concavities of the false ribs,
with the hindermost cartilages of which its margin pre-
cisely corresponds ; so that if the abdomen were pierced
from the left side posteriorly to the last rib, this organ
would escape injury. It is attached to the left half of
the great curvature of the stomach ; but the chief bulk
of it lies behind and rather above the stomach. Its an-

400 Heftection of the Peritoneum.

terior extremity lies in contact with the left lobe of the
liver ; its posterior is connected to the left kidney, and
concealed by the convolutions of the colon.

The most ready way to get a view of the pancreas
is to tear through the omentum. It lies across the spine,
in the epigastric region, under the crura of the dia-
phragm, immediately behind and a little above the
small curvature of the stomach. Its head is surrounded
by the duodenum, with which, and with the stomach
and colon, it is chiefly connected ; and its body is
pierced by the vena portarum, and has one attachment
to the spleen, and another to the left kidney.

Rejiection of the Peritoneum.

In order that the various connexions and uses of the
peritoneum may be perfectly understood, it is usual, at
this time, to trace (what the Schools call) its re/lections:
by which is meant, to show the way in which it lines
the cavity, and afterwards invests the different viscera
contained in it. The peritoneum, though, taken as a
whole, a perfect sac, is not, as far as regards the cavity of
the belly, a circumscribed bag ; at least, it is not in the
male after the descent of the testicles, for those organs
in their passage necessarily caiTy down a portion of it
into the scrotum, which consequently becomes a con-
tiguous cavity, and is one that has ever afterwards free
communication with that of the abdomen, so that water
or air will readily pass from the one to the other : not-
withstanding this however, I repeat, the integrity of
the peiitoneum itself is unimpaired. In my description
of the extensions and folds of this membrane, it imports
but little where I commence ; it is most usual to make a
beginning at the pelvis.

/

Reflect ion of the Peritoneum. 401

The peritoneum having lined the inferior parietes of
the abdomen — the recti and other muscles, passes over
the anterior part of the pubes upon the fundus of the
bladder, whence it is extended to the sides of the pelvis,
forming the vesical ligaments. Having given a cover-
ing to every part of the bladder but its neck and the
under surface of its body, it next includes the rectum, at-
taches the gut to the spine by an union of its investing la-
minie,and thus produces the mesorectum. From the basis
of the sacrum it passes upon the lumbar vertebras, whence
it soon departs to attach and invest the colon from which
it repasses upon the spine, and thus forms the mesoco-
lon. It now descends again into the cavity, making one
layer of the mesentery, to give a covering to the small
intestines, and from them extends to the great arch of the
colon ; it then joins the other layer of the mesentery, de-
rived from the pancreas, which has completed the invest-
ment of these intestines, and proceeds backward in in-
timate union with it; soon however both are reflected
again and pass onward to the stomach, and thus form
that loose production — the omentum, which consequently
consists of four layers of peritoneum. From the stomach
one portion of it passes to the spleen, and having enve-
loped and confined it, splits, and spreads ils layers over
the abdominal parietes ; another portion leaves the sto-
mach for the liver, and when it has given a like close tu-
nic to this organ, is continued anteriorly upon the dia-
phragm, which extensions, consisting of two layers, are
called the ligaments of the liver. But a portion of the
membrane passes backward from the liver to the duode-
num, whence it stretches across the pancreas to form the
anterior layer of the mesentery. The kidneys and the
pancreas do not receive peritoneal tunics, as the liver and
PART XI. 2 D

402 Diseases of the Feritoneum.

spleen do : the membrane simply passes over their miat-
tached surfaces.

Diseases of ' the Peritoneum.
This membrane is liable to inflammation of two kinds :
— acute and chronic ; of which the former appears to be
of the more frequent occurrence.

Acute peeitonitis in the horse rarely arises sponta-
neously, but is the effect of wound, strain, or some other
injury of the membrane. Of wound, as when it super-
venes upon the operation of castration ; in which case
the inflammation creeps along the cord, and extends from
the tunica vaginalis to the peritoneum : a result not likely
to happen in the human subject, in consequence of the
abdominal ring being closed. Of strain, as after some
extraordinary effort ; such as hard galloping or leaping *.
Add to these causes that the presence of hernia, or the
operation, may occasion it. In cases of this description
then, when the symptoms indicate abdominal disease, we
may suspect this membrane to be the seat of it ; for the
symptoms so much resemble those of enteritis that I
know of none that will serve us as diagnostic. Fortu-
nately for us however, this is of little or no consequence,
for the treatment of both is to be conducted by the same
means and in the same manner ; I shall therefore reserve
what 1 have to say in continuation until I have occasion
to speak of enteritis.

With regard to chronic peritonitis, I met some

* Three years ago I attended a horse that died in consequence
of a severe run with Lord Derby's hounds, in whom inflammation of
the peritoneum was the only morbid appearance discoverable after
death : the symptoms resembled those of enteritis.

Diseases of ihe PerUonemn. 403

years back with so well marked a case that T cannot con-
vey a more correct account of the symptoms, &c. than is
contained therein ; I shall therefore transcribe it, in
the abstract, from the register of extraordinary cases.
A chesnut hoi'se, the property of my father, four years
old, was attacked in the latter end of December, 1812,
with the ordinary febrile and anasarcous affection (swell-
ed legs) prevalent at this season, which by exercise, pur-
gatives, and diuretics, was dispersed in the beginning of
January, 1813. From this time until March, the horse
not only throve in condition but got exceedingly fat,
showed no further signs of ill health, and was ridden daily
by the groom. The first circumstance that attracted
notice — the ushering in of that which proved to be the
cause of his death, was a complaint from the man that
the horse " bent under him" occasionally in trotting, as if
from weakness ordiseased spine, which was accompanied
with a faltering step or two, imperfections in action never
experienced before. Soon after this, on the sixth, his
breathing became affected, and so much so that he was
exceedingly distressed if he trotted even but a short dis-
tance ; in two or three days more, his appetite began
to fail him, and about the same time his bowels became
much relaxed . My father being now absent from home,
the treatment of the case devolved upon me. Suspecting
that there was some disorder in the ahmentaiy canal and
that this was an effortof Nature to get rid of it, I promoted
the diarrhoea by giving mild doses of cathartic medicine
in combination with calomel. On the third day from this,
prolapsus ani made its appearance, which for a few hours
80 rapidly increased in volume that I with difficulty, by
the use of the poppy fomentation, by manual operation,
and by the exhibition oftinct.opii internally, arrested its

2 D 2

404 Diseases of the Peritoneum.

protrusion, and at length effected its reduction. After
the return of the gut, the animal grew daily duller and
more dejected, manifesting evident signs of consider-
able inward disorder, though he showed none of acute
pain ; the diarrhoea continued ; an aedematous sweUing
formed under the belly nearly centrically, and consider-
able tumefaction of the legs speedily followed. In this
state, on the 15th, eight pounds of blood were drawn,
two ounces of the oil of turpentine given internally, and
a fomentation was used to the belly. During the whole of
this day he remained exceedingly dejected, and appeared
insensible to what was passing around him ; in the
evening he was seized with symptoms of inflammation
of the bowels, which, in spite of another venesection
and some subordinate measures, carried him off in the
course of a few hour^. Prior to dissolution, the skin
under the belly became prodigiously distended with fluid,
and the limbs enormously swollen ; and it was remarked
by my father, who had not seen hitn since the onset of
his illness until the day of his death, (but not by us
who were in attendance) that the belly itself was of un-
usually large size.

Dissection. A slight blush pervaded the peritoneum ;
at least the parietal portion of it, for the coats of the
stomach and intestines preserved their natural white-
ness. About eight gallons of water were measured out
of the belly. The abdominal viscera, as well as the
thoracic, shewed no marks of disease.

This is the only case of the kind that has come to my
knowledge.

LECTURIi XLIII.

.^sr^ ^-^^ ^i^s*- #s*i* ^ ^ ^ ^Vv^ ^^s^

On the Stomach.

The stomach is a large musculo-membranous pouch
or bag, placed within the cavity of the belly, and des-
tined for the reception of the food. Without any ex-
ception, this appears to be the most important organ in
the body ; and the strongest proof probably we have of
its being so, is the universality of its existence, from
the highest to the lowest class of animals : this is not
the case with the brain, much less with the heart, and
it was this circumstance that led Mr. Hunter to re-
gard the presence of a stomach as the chief character-
istic between animals and vegetables. The stomach
has been emphatically denominated the organ of' diges-
tion ; for within it, the aliment transmitted by the
esophagus in a crude state, undergoes its primary and
principal change in a process the object of which is to
convert it into matter necessary for the growth, support,
and repair of eveiy part of the body.

The stomach is situated principally in the left hypo-
chondrium, which it nearly fills, extending more or less
into the epigastrium, according to its state of distention ;
its anterior part lies in contact with the liver ; its left

406

On the Stomach.

extremity is opposed to the diaphragm and spleen, it
lies in part upon the small, but mainly upon the
large intestines. It is evident that the full and empty
conditions of the stomach will affect its position in rela-
tion to the neighbouring viscera, and that the motions
of the diaphragm will alter its situation ; for during the
recession of that muscle, it must be pushed into the
umbilical region. On the other hand, the action of the
diaphragm will be interrupted by distention of the ab-
dominal viscera, and more particularly by fulness of the
stomach ; for increased pressure will counteract its ef-
forts to recede, and the chest, under these circum-
stances, will be expanded by the other inspiratory
agents — the intercostal muscles, and those passing from
the ribs to the fore extremities. This accounts for the
inaptitude of horses, recently fed, to undergo violent
exertion, and the increased embarrassment in respiration
that hard work then occasions — why they should be
sooner blown, and why they will, if pressed, absolutely
sink from exhaustion : hence the practice of keeping
hunters short of water, and of feeding them unusually
early, and on corn only, on the morning of hunting.

The stomach has been not inaptly likened to the air-
bag of a set of bag-pipes : I should probably fail in
conveying so good an idea of its shape by any other re-
semblance. For the convenience of description, it has
been divided into several parts : e. g. an tipper and an
under surf ace ; a left or large extremity/, which is formed
into a large blind pouch or cul-de-sac, called its fundus ;
and a right or small end, which opens with a bend into
the duodenum or first intestine; a large curvature to
which the spleen is attached, and a. small one extend-
ing between its two openings ; the former of these, in

Oh the Stomach.

407

the living animal, is turned upwards and backwards,
the latter downwards and forwards.

The stomach has two orifices. One, in which the
esophagus terminates, is situated about the centre of
its anterior part, at the right extremity of the small cur-
vature, and takes the name of cardia : it is constantly
closed but when matters are passing into or out of the
organ. The other is placed at the termination of the
right or small extremity, and opens into the duodenum ;
though it has the power of closing, it is mostly open.

The stomach is fastened in its place by its union with
the esophagus and duodenum. It has other connex-
ions, but they are of a peritoneal nature : — at its
great curvature it is attached to the spleen and colon
by the omentum, at the cardia to the diaphragm by a
fold of peritoneum, and near its pyloric end to the liver
by an extension of the same membrane. The esopha-
gus, previously to entering the stomach, makes a sud-
den incurvation downward, by which an angle of such
a nature is formed between the stomach and it as to
have the effect of a valve in preventing the regurgitation
of aliment.

Perhaps no animal, in proportion to its size, has so
small a stomach as the horse. Let us only compare it
with that of the human subject : the stomach of a middle-
sized man (a man weighing 12 stone) will contain more
than three quarts of water ; whereas that of an ordinary-
sized horse, whose body exceeds his in weight and
bulk by eight times, will not hold more than three
gallons, or four times the quantity of the man's. We
are to bear in mind, however, that the stomach, like
other hollow muscles, has the power of accommodat-
ing itself to the bulk of its contained matters ; so that

408

On. the Stomach.

we are not to draw conclusions of its comparative volume
barely from the state of fulness in which we may find
it. At another time, I shall endeavour to shew why
Nature has given so small a stomach to the horse ; an,
animal whose consumption of food we know to be enor-
mous.

The stomach has four coats. The first is that which it
derives from the peritoneum, thence called the 'peritoneal
coat: at the greater curvature the layers of the omen-
tum disunite and separate, and, including the gastric
vessels and nerves, spread uniformly over every part of
the organ. In texture, it is the same as the parietal
portion of that membrane, and like that exhales a serous
moisture from its outward surface, to prevent friction
between the stomach and those viscera with which it
lies in contact. Inwardly it adheres, by a fine dense
cellular tissue, to the next tunic.

The second or muscular coat, which is also white, lies
immediately underneath the peritoneal. It is composed
of two orders of fibres, which may be distinctly seen
when the stomach is distended with air, and its perito-
neal covering stripped off. The exterior fibres run in
a longitudinal direction, and are fewer in number and
weaker than the interior, which take a circular course,
and are strong and well-marked, particularly about the
pyloric extremity, where they appear to be blended with
those of the duodenum : from this arrangement of the
fibres, the cavity can be diminished in every dimension.
If we slit open the pylorus, we shall find a valvular pro-
jection, forming the boundary line internally between the
stomach and the intestine ; this is called the valve of the
pylorus : it is made up of a circular production of mus-
cular fibres enveloped within a fold of the mucous coat.

On the Stomach.

409

Though this valve certainly tends to prevent the return
of alimentary matter from the intestines, yet do phy-
siologists not regard this as its principal use ; they be-
lieve that its operation is rather that of preventing the
escape or expulsion from the stomach of any crude or
indigested aliment — of solid matters that have not
been duly softened and dissolved, into the intestinal
canal. I say solid matters, for fluids pass freely through
it at all times into the intestines, without any deten-
tion whatever in the stomach. Actual experiment
evinces that they do ; but we may also satisfy our-
selves of this fact by contrasting the quantity of water
a horse that is thirsty will take at a draught with the
known capacity of his stomach.

The stomach of the horse species differs remarkably
from that, I believe, of all other quadrupeds, with the ex-
ception of the graminivorous monogastric, in having a par-
tial cuticular lining, which may be considered as a third
coat : by turning the viscus inside out, or by slitting it
open along its great curvature, this part, so conspicuous
for its white and wrinkled surface, will be distinctly ex-
posed to view. And now we can trace its well-defined
border, forming the boundary line between it and the
fourth coat, the course of which is waving or serpentine,
something like the figure of an S. This lining extends
over the cul-de-sac or left extremity, covering not quite
one-half of the whole internal surface of the stomach.
We commonly find it thrown into wrinkles, termed rugcR,
which sometimes are so disposed as to form a sort of net-
work : this is owing to its not being possessed of sufficient
elasticity to accommodate itself to the varying capacity
of the organ. This substance is of the same nature as
the lining of the esophagus, with which at the cardia

410

On the Stomach.

it is continuous. Numerous small openings are visible
upon its surface, through which issues a mucous fluid
that is of use in the digestive process.

The fourth, mucous, or villous coat, extends over that
part of the stomach not lined by the cuticular. Its sur-
face is of a yellowish cast, inclining in some places to
a red. It is soft, fine, and cellular in its texture, and
possesses considerable vascularity. When closely and
attentively examined, it is found to present inwardly
numerous little ragged or shaggy processes, which,
from their giving it the appearance of velvet, have re-
ceived the name of villi; these appear to be rriade up
principally of the minute ramifications of blood-ves-
sels, which we believe to perform the office of the gas-
tric secretions : by some the villi are supposed to have
numerous minute glands in their composition ; but, in
point of fact, we do not know precisely what is their
intimate structure. This coat, as well as the cuticular,
occasionally exhibits numerous rugae upon its internal
surface, which disappear upon extension.

With the exception of the brain, for no organ has
Nature made more ample provision to insure a supply of
blood than for this. Its arteries are — the superior gastric,
which is derived from the posterior aorta, and is distri-
buted to its small curvature, and upper and under sur-
faces ; the right and left gastric, which branch from the
hepatic and splenic arteries, and take their course
along its great curvature ; besides numerous small ra-
mifications from the trunk of the splenic, called the
vasa brevia. Most of these vessels take a tortuous
course, and by so doing accommodate themselves to
the varying volume of the organ. Their ultimate dis-
tribution is to the villous lining, in which they ramify

On the Intestines.

411

to great minuteness, and exist in such abundance as to
render it uniformly red when injected with size and
vermilion. Its veins, which are somewhat larger in
size than the arteries, and have no valves, terminate in
the vena portae. The stomach possesses numerous ab-
sorbents, and is well supplied with nerves from the eight
pair and sympathetic.

On the Intestines.

The intestines are cylindrical, musculo-membranous
tubes of various dimensions, forming one continued
but convoluted canal from the pyloric orifice of the
stomach to the anus, in which the process of digestion,
begun in the stomach, is completed.

These viscera, taken collectively, cannot be said to be
lodged in any particular regions ; they are spread over
the inferior part of the belly, immediately supported by
the abdominal muscles, and are found, one or more of
them, in every region of a cavity of which they occupy
by far the greater part.

The intestines of the horse are ninety feet long, or
between eight and nine times the length of the body :
those of the human subject are about thirty -four feet
long, or six times the length of the body *.

These viscera are divided into the small and large

* I was at first undetermined in my mind how 1 should draw this
comparison. I put down the ordinary height of men at 5 feet 8 inches.
I tlien extended a hne from the forehead, above the orbital arch, of
a middle-sized horse, to the point of the hip, and thence carried it
to the ground : this I found to measure 11 feet. These then, with
the relative lengths of the intestinal canals, I have taken as my
data. Whatever objections they may be liable to, wc may draw this
conclusion from them •.■^that the intestines of a horse greatly exceed
in proportionate length those of a man.

412

On llic liUeatiiies.

intestines ; the latter, as their name implies, exceed in
magnitude the former ; and each of these divisions is
subdivided into three parts that have received particular
names. But I shall take into consideration the general
structure of these tubes before I proceed to a detail of
their peculiarities.

An intestine is composed of three coats : the first or
external is called the peritoneal; the second or middle,
the muscular ; and the third or internal, the villous or
mucous coat.

The peritoneal coat is simply a covering continued
from the peritoneum itself, which includes the mesen-
teric vessels and nerves in its way to the intestines, and
connects them to the spine, to one another, and to
other viscera ; it intimately adheres by fine cellular mem-
brane to the muscular coat ; and it serves to strengthen
the guts, to furnish a lubricating watery perspiration,
and either to restrain their motions within certain limits
or confine them altogether to their places.

The muscular coat, like that of the stomach. Is com-
posed of two orders of fibres : — a longitudinal, running
immediately underneath the peritoneum and consisting
of a few pale scattered fasciculi ; and a circular, of which
the fibres are placed more inwardly,- are stronger, more
numerous, and more distinct. By a combination of
their actions, the intestine is contracted in every direc-
tion ; for while the former will have a tendency to
shorten it, the latter order of fibres will operate forci-
bly in diminishing the calibre of its canal.

The villous or mucous coat of the intestines, though
in its general appearance it resembles that of the sto-
mach, differs from it in many essential particulars. It
is of infinitely greater extent, presenting a surface for
absorption and secretion, exceeding even that of the

Small Intestines.

413

common integuments. Its villi (more especially in the
small intestines) instead of consisting principally of
minute blood-vessels, are crowded with lacteals, which,
as I remarked in my lecture on the absorbents, are sup-
posed to take their origin from them by open mouths *.
Besides the villi, its interior is studded with numerous
glandules, the size and distribution of which vaiy
somewhat in the different guts ; they secrete a glary,
mucous fluid, which they pour forth upon the surface of
this membrane, in order to sheath and defend it from
the acrimony or mechanical irritation of the aliment,
(and from any other mechanical or chemical irritant) and
to facilitate its passage through them. In the small in-
testines of the human subject, this coat is collected
into numerous transverse folds, called valvulae conni-
ventes, from their being supposed to have the effect of
so many imperfect valves ; but in those of the horse no
such structure exists, it not being requisite (for reasons
I shall hereafter give) to retard the passage of the ali-
ment here, or to multiply the lacteal apparatus. Hav-
ing described the appearance and structure of the in-
testines in general, I shall proceed to point out the pe-
culiarities of each of them, beginning with the

Small Intestines.

The small intestines, though smaller in their calibre
than the large, exceed them in length. They are con-
stituted of three parts or subdivisions, called the duode-
num, jejunum, and ileum.

The duodenum is more capacious than either of the
others, especially at its beginning, though in length it

* Part I. Lect. vii. page 110.

414

Small Intestines.

is much inferior to them : its name however is inappli-
cable in the horse, for it is nearly twice twelve inches
long. I have already given its situation, course, and
connexions, I have no need therefore to enter again
into their detail here ; all I wish to repeat is, that it
begins at the pylorus of the stomach, and having
crossed the spine terminates in the jejunum. It not
only differs from the others in being larger and shorter,
and in being straighter, but in being redder — more vas-
cular than either of them ; it is however at once distin-
guished from all the other guts, both large and small,
by receiving the ducts of two important glands, situ-
ated near it, viz. the liver and pancreas : these tubes ter-
minate by one common orifice upon its internal coat,
about the distance of six inches from the pylorus.
Unlike the jejunum or ileum, the duodenum receives
only a.partial covering from the peritoneum, by reflection
over its inferior and lateral parts, the superior surface
being attached to the liver, kidney, and spine by cellular
membrane only. Its motions are exceedingly li-
mited.

The jejunum, paler, less in calibre, and much longer
than the duodenum, is extremely tortuous in its course,
and floats about loosely within the cavity with the
convolutions of the ileum : there is, in fact, little or
no distinction between these guts, except that the lat-
ter, by an arbitrary division, is longer by one-fifth
than the former.

The ileum then is the longest of the small (and in-
deed of all the) guts : it forms the greater part of that
convoluted tube which lies principally in the umbilical
region. Probably it is still less vascular, being some-
what paler, than the jejunum ; it is certainly less in

Large Intestines. 415

circumference towards its posterior extremity, which
ends, rather abruptly, in the beginning of the large in-
testines. The jejunum and ileum being attached to the
spine by that extension of peritoneum called the
mesentery, float about within the cavity, varying their
situation and relative position with the volume of the
stomach and stage of the digestive process.

The small intestines are supplied with blood by the
anterior mesenteric artery, a vessel of large size, that,
after having divided and subdivided many times, sends
off numerous small branches, which ramify to great
minuteness between their muscular and villous coats.
Their veins, which have no valves, return the blood
into the vena portse. The nerves come from the mesen-
teric plexus.

These intestines altogether will contain about eleven
gallons of fluid.

Large Intestines.
The large intestines are shorter, but considerably
more bulky, than the small ; they also differ remarkably
from the latter in their general appearance — in being
puckered into numerous plaits or folds. This peculia-
rity is occasioned by some longitudinal nmscular bands,
which, being shorter than the rest of the intestine,
pucker its coats — contract them into folds: to these
bands are appended numberless little, fatty processes,
to which anatomists have given the name of appendicula
pinguedinosa. Internally, the large intestine is divided
into many little elliptical pouches, called cells, with par-
titions between them ; which, though they appear to
answer the same purpose as the valvulae conniventes of
the human intestine, viz. the retardation of the passage

416 Large lntesti?ies.

of the aliment and the augmentation of the surface for
absorjjtion, diflfer essentially from them in being consti-
tuted of all the coats of the gut. In other respects, the
structure of the large and small guts is not materially
different.

The large intestines, like the small, are three in num-
ber, viz. the cacum, colon, and rectum : they do not how-
ever bear the same degree of likeness, one to another,
as the divisions of the small.

The cacum or blind gut, the first subdivision of the large
intestines, originates in a large capacious head or recep-
tacle, called the coccum caput coli, or blind head of the
colon, from which it extends downward, and terminates
in a blind extremity or cul-de-sac : from this part, in the
human subject, proceeds a slender elongation of gut, about
the size of a quill, denominated the appendix vermiformis.
Before I proceed further in my description of the coecum,
I shall direct my attention to the manner in which the
small are united to the large intestines. The termination
of the ileum projects for some way into the caput coli, and
does so at right angles both with it and with the coecum,
so that the contents, having once passed the ileum, are
not likely to return ; independently of this preventive con-
trivance however, there is a valve at this part very like that
at the pylorus. This valve, which is called the valvula coli,
is formed of a doubling of the internal coat, within which
is folded a circular band of muscular fibres ; in its shape
it resembles a half-moon, so that it is not equally pro-
minent at every part : its office is that of permitting cer-
tain alimentary matters and all fluids to pass from the
ileum, but to debar their return.

The coecum differs from all the other guts, in having
but one opening into it; consequently all matters that

Large Intestines. 417

hav€ once entered it, must re-ascend into the caput coli
in order to continue their route. The exterior of it is
braced hy three longitudinal bands, and puckered by them
into three sets of cells internally ; these cells, which are
abundantly supplied with blood-vessels and absorbents,
extend the surfaces for absorption and secretion, at
the same time that they prolong the stay of the con-
tained matters. The contents of this gut after death
are generally found to be fluid ; it would appear indeed
to be the proper receptacle for fluids ; for if we give a
horse water, the greater part of it will flow at once
through the stomach and small guts and collect within
the coecum. It will hold about four gallons of fluid.

The colon in the horse is a gut of enormous size, of a
peculiarity of figure, as well as course, and is the most
capacious and longest of the large intestines : it will con-
tain about twelve gallons of water, a greater quantity than
what all the small intestines will hold together. It be-
gins in the coecum caput coli, that voluminous dilatation of
gut between the termination of the ileum and mouth of
the coecum, and soon expands into a cavity of greater
dimensions than even that of the stomach itself; having
attained this bulk, it begins to contract, and continues to
do so gradually during its course around the coecum,
until it has completed its second flexure, where it grows
so small tiiat it scarcely exceeds in calibre one of the small
intestines ; and though from about the middle of this turn
it again swells out by degrees, it never afterwards acquires
its original capaciousness : indeed previously to its
junction with the rectum it once more diminishes, and
at length assumes the calibre and general appearance of
that gut. Its first flexure has three longitudinal bands,
which give it a plicated appearance externally, like the
PART II. 2 E

418 Large Intestines.

coecum, and form it into very many deep and capacious
cells within ; its last turn however has only two, and the
cells of it are not only less numerous, but are much shal-
lower as we approach the rectum. This fact tends much
to strengthen our opinion of the uses of these cells ; for
in this part of the alimentary canal the matters are found
to be feculent, no farther absorption is required to be
made from them therefore, and of course they need not
be longer detained. Not only however are the cells fewer
and less distinct at this part, but their supply of blood is
diminished ; so that the intestinal secretion, which it is
believed contributes to the completion of the digestive
process, is here probably wanting altogether, or but very
sparingly produced.

At the upper margin of the pelvis the colon termi-
nates in the rectum, in the horse a short and nearly straight
gut, which is continued thence to the anus. It will hold
about three gallons of fluid. This gut, independently
of its general figure and dimensions, differs from the
coecum and colon in possessing but a partial peritoneal
covering, and in having no muscular bands, nor cells.
The extremity of the rectum, more capacious than the
anterior part of it, is' furnished with a circular muscle —
the sphincter ani ; which, with the adipose matter in
which it is cushioned, gives that prominence to the anus
so remarkable in the living animal. The use of the
sphincter is, by keeping the anus closed, to retain the
faeculent matter until so much of it be accumulated in
the rectum as to create a desire to discharge it. So
that the sphincter is a muscle that is in constant action,
otherwise the feeces would be very often escaping, and
so far it acts involuntarily ; but in order to expel them,
the animal has recourse to a voluntary power — to the

Large Intestines. 419

muscular coat of the gut, (which is stronger than that of
the other intestines,) aided by the abdominal compres-
sion principally of the internal oblique and transverse
muscles.

The large intestines receive their blood from a vessel
of much less size than that which supplies the small,
called the posterior mesenteric, a branch of the posterior
aorta, whose distribution is similar to that of the ante-
rior. Their veins end in the vena portse. Their nerves
spring from the mesenteric pexus.

2 E 2

LECTURE XLIV.

On the Diseases of the Stomach.

The horse is occasionally the subject of disorder in
the stomach, which may be either of a functional or or-
ganic nature : — the one owes its generation to the kihd
and quantity of the food, or to some mis-management in
feeding ; the other arises from the presence of irritating
matters, mechanical or chemical, within the villous or
right extremity of the organ.

Very many of the medicines made use of in veterinary
practice are of so virulent a nature that they are seldom
or ever given in large doses without producing more or
less inflammation of the villous coat of the stomach :
the aloes in a common dose of physic almost always
does it, whence the nausea and loathing-of food that so
generally result from its administration ; blue vitriol,
corrosive sublimate, arsenic, verdigrease, &c. have a
similar but more potent effect. Now, it is to the inflam-
mation of the villous coat, (gastritis,) excited by an
overdose or the improper exhibition of one or other of
these poisonous substances, that I shall at present con-
fine my observations.

The symptoms occasioned by the sudden presence of
poison in the stomach, supposing it to possess the

On the Diseases of the Stomach. 421

common corrosive or caustic properties of the metallic
salts I liave just mentioned, or of the mineral acids
or caustic alkalies, will vary with the quantity or ac-
tivity, but not much with the specific nature of the sub-
stance introduced ; but> should the poison have been ad-
nunistered for some time — medicinally, (for poisons are
all innocuous when sufficiently divided or diluted,) or
should it be of a vegetable kind, then the symptoms
may and will vary to a very considerable extent.
Without attempting to lay down the diagnostic signs
by which any specific poison may be known to have
been (clandestinely) given, which, were I prepared for
such an undertaking, would take up far too much of my
time and space here, I shall portray the leading symp-
toms resulting from the abuse of arsenic, corrosive subli-
mate, and blue vitriol, since they are the most common and
almost the only substances likely to be so administered.
The first symptom is nausea — the horse refuses his food :
the experienced practitioner, aware of this, when he is pre-
scribing a medicine the efficacy of which is doubtful or
unknown, is always on the watch for failure of the ap-
petite. This state of nausea is often accompanied with
a copious flow of saliva — he froths at the mouth.
Upon this fever quickly supervenes, followed by the ex-
pression of acute pain in the bowels : — the horse paws,
turns his head round and looks with extreme distress at
his flank, lies down, rolls about the stall, rises up again
in gr^at agony, breaks out into a profuse perspiration,
and respires very quick and with painful embarrassment.
The pulse at first is simply accelerated, it then becomes
contracted almost to a thread, and at length quite imper-
ceptible. Great prostration of strength now seizes him,
he reels about in attempting to walk ; he either passes

422 On the Diseases of the Stomach.

copious evacuations, or he has a painful tenesmus and
voids nothing but mucus ; cold sweats break out ; he grows
delirious from torture, throws himself down with exces-
sive violence in the stall, becomes convulsed and dies

In cases of death from the mineral poisons, the villous
coat of the stomach generally exhibits a partial, but in-
tense inflammation, which will of course vary with the
virulence of the poison, and the length of time it has
been administered : there are red, purple, or black
patches, or some of each, upon its surface, it is thick-
ened, and perhaps covered with flakes of lymph; it
may also be ulcerated in places, or it may be gangrenous.
The cuticular coat, though it is not susceptible of any
vital action, is now and then spotted wilh black eschars
from the caustic nature of the poison. The small and some-
times the large guts are also highly reddened in various
parts ; and where arsenic has been given for several days,
the coecum and colon are not infrequently found black
and rotten — gangrenous : one of the best tests however
of arsenic having been given is the very off^ensive fetor
that is perceived from the liberation of gas, instantly the
bowels are opened.

Unfortunately for the veterinary surgeon he has no
means by which he can excite the immediate ejection *
(by vomiting) of the noxious matter from the stomach.
His only alternative, and it should be as promptly prac-
tised as possible, is the dilution of the ofi'ending matters
taken in : let the horse be copiously drenched with warm

* I think that tlie 'newly invented stomach [syringe may prove
of great service to the veterinary practitioner in this case, and in
some others : there is no more difficulty in passing a hollow flexi-
ble tube into the stomach than there is in introducing a common
probang.

On the Diseases of' the Stomach. 423

water, for lie will seldom drink any at this time, or some
oily or mucilagiuoiis fluid ; though 1 do not know that
these last possess any advantages over simple water —
that first obtained is always the best. The practitioner
should endeavour to detect the nature of the poison
swallowed; though, if it be arsenic, little or nothing can
be done by way of rendering it innocuous, excepting free
dilution. In the case of corrosive sublimate however,
albumen or whites of egg are recommended strongly
by Orfila as antidotes. At the same time, we ought to
draw blood very freely, blister the belly, and at short
intervals throw up copious clysters. It is a most desir-
able object to induce and promote a free discharge from
the bowels; but I fear we have no medicine that can be
confidently administered with that view but what would
itself prove a fresh irritant to the inflamed or ulcerated
alimentary passages.

The horse is occasionally the subject of disease in
consequence of preter-natural distention of the sto-
mach, either by food or air. Mr. Bracey Clarke
in his " Essay on the Gripes" has detailed a case of the
former, which he calls " coactio, or gorged stomach*."

* A brewer's horse, that had at times been the subject of indi-
gestion, was taken very ill in the dray, staggering about and endea-
vouring to lie down ; in which painful condition he continued out
several hours. When he came home, " he pawed now and then
with his fore feet, but not violently, lay down, and after a few
minutes resting, got up again ; his breathing was agitated, but not
v iolently so, his eyes fixed and staring, and watery, expressive of
internal suffering. He passed the night much in the same manner ;
(having by Mr. C.'s directions had xuarm beer and ginger given
to him ;) " in the morning the gripe tincture was administered, and
he was bled, which seemed to relieve hun very much ; his symptoms
all returned however, and his breath and saliva, which froliicd ou

424

On the Diseases of the Stomach.

Of distention from air (tympanites ventricular is) and
consequent death, I myself, in tliis last summer, met with
a very interesting case. Oxen, cows, and sheep, from
being permitted to graze voraciously in luxuriant pasture
(especially of young clover) not infrequently have the
paunch blown up with air, in consequence of an over-
distention with, and subsequent fermentation of, the
succulent food ; I have examined but one case of it
however among horses. In cattle, it is called the
hove*. '

of his mouth, became very offensive, and I then began to suspect
it was a case of gorged stomach. He died on the fifth day after the
attack ; opened, his stomach was found unusually distended with
food, which he could not digest." Clarke's Ussay on the Gripes of
Horses, p. 21.

* On the 5th of September, 1824, a young bay marc belonging
to die Artillery was admitted into the infirmary with symptoms of
colic, for which she had lost Ibviij. of blood before she came in.
Her symptoms were of the most violent and alarming description.
She sweated profusely from paroxysms of agonizing pain, worked
hard and quick at the flanks, and had a thready and almost im-
perceptible pulse. The following drench was prescribed to be given
immediately: — Tinct. Opii et 01. Terebinth, aa. Jitj. Decoct. Aloes
3vj. M, In the course of half-an-hour this was repeated; but shortly
after she vomited the greater part of it by the mouth and nostrils. No
relief having been obtained, Ibxii. of blood were taken from her, and
this drink given. Tinct. Opii ^iv- Decoct. Aloes ^x\j. 01. Carui 3ft-
M. a stimulating embrocation nibbed upon the belly, and large and
frequent clysters injected. In another hourthis drench was repeated ;
and, for the fourth time, during the succeeding hour; both of which,
before death, she rejected as she had done the second drink. Not-
withstanding these active measures were promptly taken, she died
about three hours after her admission. Having opened her, we found
the stomach prodigiously distended with air; it was, at least, three
times its ordinary size. When punctured, it subsided to about two-
thirds of its former bulk. It contained masticated oats and hay,
swimming in a greenish yellow fluid, which emitted an offensive

On the Diseases of the Intestines. 425

Lastly, llie stomach may be ruptured. Mr. Clakke's
Essay furnishes me with this account of a case of it. —
" Choidapsus, ruptured stomach. When the stomach
ruptures, its contents pour from the nose and mouth ; 1
never saw a case of this kind, but I record it from the
report of my esteemed friend, Frederick Nash,
who was present at a case of this sort wlien living at
Cambridge. Death immediately follows *."

On the Diseases of the Intestines.

The intestinal canal of the horse, like that of the
human subject, is occasionally the seat of inflammation,
either acute or chronic, and of spasm ; it also now and
then becomes obstructed, or partially so, by calculous and
stercoraceous concretions. The acute diseases to which
it is liable, run their course with great rapidity, being in
general more speedily fatal than those of the cheet. And
they not only demand the utmost vigilance and activity
on the part of the practitioner, but call in an especial
manner for the exercise of his judgment ; for the issue
of the case often hangs by a thread, and that thread is
broken if his decision prove to be erroneous. I will
venture to affirm, that in no instance are the remedies of
the soi-disant veterinarian so cruelly misapplied as in
the one before us.

Inflammation may invade the peritoneal, muscular,
or mucous coat of the guts : of the first {peritonitis,) I
have already spoken ; of the second {enteritis,) I shall
now give an account, and shall follow it up with one of
the third, {diarrhxa.)

odor. Had we suspected the presence of air, we would have at-
tempted to have introduced a flexible hollow tube into the stomach.
* Clakke's Essay mi the Gripes.

426

Etiteritis.

This disease consists in an inflammation of the mus-
cular part of the gut ; it differs therefore in its seat,
and, as we shall hereafter learn, in its characters or
causes, from the other two, more particularly from diar-
rhoea. Among others who have written on this disease,
I observe that Professor Peall entertains a different
opinion of its seat *. I do not deny that the peritoneum,
or even the mucous coat, may participate of the inflam-
mation, but I aver that the substance of the gut, i. e.
what intervenes between the peritoneal and mucous
coats, the muscular and cellular structure, is primarily
and principally affected. Slit open the intestine after
death, and you will perceive but little or perhaps no
reddening of its interior though the exterior resembles
a piece of scarlet velvet ; even this however is but an
illusion, for if you strip off the peritoneum, you will
find that membrane still transparent, or scarcely blood-
shot; whereas, had it been the part principally dis-
eased, it would not only have been intensely red
and opaque in itself, but have left the timic under-
neath comparatively white. Acute peritonitis then is a
distinct disease from enteritis ; and, although we have
no infallible symptom of discrimination, we shall rarely
or never give a false diagnosis if we remember that the
former is the result, almost always, of particular local

* " The horse's bowels, moreover, are subject to two distinct spe-
cies of inflammation. One is comparatively mild in its nature,
being confined to the villous or internal coat, &c. — The other affects
the peritoneal coat of the intestines, is highly dangerous in its na-
ture, and is almost always attended with a costive state of bowels."
Page 184.

Enteritis.

427

causes : in fact, 1 never knew it to be an idiopathic affec-
tion. As far as regards these affections however, diag-
nosis is but of little importance ; both, in the acute
stages, require the same remedies, and the same active
employment of them : their course is alike rapid, and
their tendency equally fatal.

Should we perchance be led to examine the horse a
little before this disease has manifested itself, we may
generally detect such febrile symptoms as usher in most
of the other acute inflammatory affections : — such as
dulness, loss of appetite, shivering, erection of the
coat, and actual coldness of the ears and legs, succeed-
ed by heat of skin, dryness of mouth, frequency of
pulse, and short and quick respiration. But in the
majority of, cases we see nothing of our patient prior
to the accession of what may be called the essential
symptoms. The horse, apparently in excessive pain,
paws, occasionally strikes his belly with his feet, lies
down, and, having rolled once or twice upon his back and
stretched himself along the stall in great agony, quickly
rises again, turns his head round from time to time, and
looks withwildness and extreme anxiety at his flank, and
groans ; his bowels are constipated, his belly is tense
and tympanitic, and his pulse is a hundred, is small,
and has a remarkably sharp beat under the fingers.
With respect to the constipated state of the bowels, we
may be misled at the onset of the disease from the occa-
sional passage per anum of some hardened dark-colored
faeces ; but these are only some that have been lodged in
the canal posteriorly to the inflamed parts, which, from
the irritation they now create, become discharged. The
tension or tympanitic state of the abdomen is not only
perceptible to the feel, it may be demonstrated by com-

428

Enteritis.

paring the present circumference of it with the gii't of
the surcingle which the animal is in the habit of wear-
ing.

These symptoms, unless some relief be speedily af-
forded, assume a more alarming character. The ani-
mal becomes exceeding restless, he is up and down eveiy
minute, bi'eaks out into profuse sweats, groans and
casts a painfully expressive and cadaverous look at his
flank ; no pulse can be felt, either at the jaw or the
side, and the respiration, which is now even quicker
than the pulse becomes so short and distressing to
him that we imagine every pufF he makes must be his
last : cold sweats bedew his coat, he groans and
plunges with agony, delirious he casts himself headlong
in the stall, is seized with violent struggles as he lies,
and having raised his head twice or thrice to his side,
suddenly stretches himself out, gasps, and expires.

I said before, that it was not of importance to in-
quire whether such symptoms belonged to enteritis or to
peritonitis, as, in either case, I should pursue the same
treatment ; it is not so however with regard to colic or
gripes, with which we are also likely to confound this
disease : such a mistake would subject our patient to a
course of remedies of so injurious a nature, that it
would have been truly fortunate for the suffering ani-
mal if we had not been called in at all. I shall give the
diagnosis in speaking of colic.

Great stress has been laid on the fatal effects of cold
in producing this disease ; but, for my own part, I have
little hesitation in saying, that of all other causes it
should be named last. Were I to turn a hundred
horses out into a strawyard during the winter, that
had been habituated to warm and comfortable stables,

Eitterilis.

429

I should not anticipate that one would have an attack
of enteritis. The most common excitants of it are —
excessive and long continued exertion, and that occa-
sional, high and irregular feeding, and irritations and
obstructions of various kinds in the bowels. If a horse
be galloped so as to distress hiui exceedingly in his
respiration, what is called blown, the mischief likely to
result will be of a pulmonary nature ; if, on the other
hand, his course be such that he retains his wind,
though, at length, he becomes exhausted from the conti-
nuance or repetition of exertion, we may be apprehen-
sive of inflammation of the alimentary canal. Horses
high-fed and but occasionally worked, are subject to
irregularity in their alvine discharges, and to habi-
tual costiveness, and this predisposes them to an at-
tack of enteritis. Calculous or other indigestible mat-
ters, as well as an accumulation of hai'dened fceces, may
prove the exciting cause, by obstructing the passage
or irritating the lining of it : in the latter case it is ob-
vious that any concussion of body, or violent action of
bowel at the time, may induce the irritation. Intro-
susception, of which I have seen one instance, may
produce it ; strangulation, or a twisting of the gut,
may cause it ; and, for I do riot deni/ the fact, in some
cases, cold.

Pneumonia, though comparatively a rapid disease in
the horse, is not, generally speaking, near so quickly
fatal as the affection now under our consideration : fre-
quently the animal will fall a victim to enteritis in the
course of a very few hours from its apparent onset. We
are not only therefore to follow up with more than ordi-
nary alertness any secondary means that may tend to
give a check to it, but, unawedby the apprehensions of

430 Enteritis.

those around us, pursue a determined mode of practice
from the very beginning. With a lancet or a large
phleme make a free opening into the jugular vein,
and thence detract, should the symptoms be urgent,
two or even three gallons of blood, according to the size
and strength of your patient : one circumstance alone
ought to induce you to pin up the neck before this
quantity has flown ; and that is, the approach of some-
thing like fainting, indicated by the animal's reeling, or
being likely to fall, from sudden prostration of strength.
The questions you are now to put to yourself are, what
are the best means to produce speedy and copious eva-
cuations ? — are there any purgatives that I can employ
for this purpose ? — and what are those purgatives ?
The common ratio medendi shows us, they should be
such as will least offend the bowels already under ex-
cessive irritation. Professor Peall prescribes one
quart of castor oil, and adds, " This is the only medi-
cine that can with safety be exhibited by the mouth in
this disease." Certainly aloes, and the croton oil,
being drastic purgatives, seem, as such, Uable to objec-
tion ; but I cannot agree with the learned Professor,
that aloetic medicines " operate as a poison" here, nor
do 1 see the same objection to the neutral salts, could
any of them be depended on as purgatives (which, as far
as myknowledgeof their effects extends, they cannot*)
that he appears to insinuate.

With respect to castor oil, I shall hereafter show, as
the result of my experiments, that it is extremely un-
certain in its effects, and that its operation, even in a
healthy subject, is not unattended with danger; for

'* Vide Lecture " On Purgation and Purgative Medicines."

Enteiitis.

431

which reasons I must enter my protest against its ad-
ministration altogether. Seeing then that we have no
purgative of that mild nature which, it is the opinion of
most professional men, is a sine qua non in this disease,
I must dissent from the established rules of practice and
recommend a/oes : rather indeed than let my patient die
with unopened bowels, I know of no certain purge that I
would not give, nor feasible measure I would not have
recourse to. But, wherein consists this dreaded evil ?
Human physicians of the greatest note are in the habit
of giving calomel and colocynth, and why should not
veterinary surgeons give aloes in enteritis ? It is not
the villous but the muscular and cellular structure that
is the seat of disease ; and therefore we are not, as we
have been led to imagine, applying the aloes to an in-
flamed surface ; and even if we were, are we quite cer-
tain that it is more irritating than castor oil, or neutral
salts, or any other medicine we may employ ! But I
would exhibit the aloes in solution, and for three rea-
sons : — first, because its operation is thereby likely to
be accelerated ; secondly, with a view of rendering it
less irritating ; and lastly, to purify it*. Calomel, as
a purgative, is not only a very uncertain but a very un-
safe medicine, and as such is unavailable in any case ;
but, if the aloes did not answer my expectations, I
should not hesitate to prescribe the croton seeds f .

Copious clysters are always to be often injected,
raking % having been first performed ; they may be
composed of soft soap and warm water, and rendered

* The formula will be found in a note at page 194, Part I.
f Vide Lecture " On Purgation and Purgative Medicines."
X By raking is meant, the manual operation of removing scybala
from the rectum.

432

Enteritis.

more stimulant by the addition of common or epsom salt,
or of a small quantity of aloes. Did these injections
fail to procure evacuations, I would throw up the tobacco
enema * : Mr. W. Goodwin tells me that he has employ-
ed fumes of tobacco in one case with apparent benefit.

As soon as we have bled our patient, administered to
him from ^iss. to ^ij. of aloes in solution, raked him,
and given him a clyster, we may make an attempt to
foment the abdomen with hot water ; but this is rarely
practicable when the symptoms are violent. We are re-
commended by some also to wrap the belly in recently
flayed sheep's skins ; but even if they could always be
procured, they cannot in all cases be kept applied ; and
when they are laid on, I am inclined to think that their ef-
ficacy amounts to very little. To these emollient means ,
I prefer myself counter-irritation. Here again has arisen
a variance in practice. One would think that no man
of experience would insert a rowel or a seton in a horse
that, if he be not relieved by the third or fourth hour
from the attack, will be, in all probability, past reco-
very ; in the first place it can have no effect in the time,
and in the second it never will discharge so long as the
system is harrassed by violent inflammatory action.
Counter-irritants should be such as will take speedy or
immediate effect ; and one of the best consists of equal
parts of ol. terebinth, and infus.lyttae. Without cutting
off" any hair, let from six to twelve ounces of this mixture
be well rubbed over the surface of the belly ; and when
the extremities are cold, I am far from condemning
their practice who direct that about one-fourth of that

* R Aq. Fervent. Cong. i.
Fol. Nicotiana; Jiv.
Infus. per horani ct cola.

Enteritis.

433

quantity be rubbed upon the legs. When the symptoms
are extremely urgent. Professor Peall, in my opinion
with much feasibility, recommends firing the abdomen
with a broad and flat, or slightly concave iron, so as to
produce considerable inflammation without the hazard of
sloughing the integument. As a powerful stimulant,
the mustard poultice may be rubbed in * ; and, last of
all, should the abdominal surface still remain cold,
and the bowels constipated, boiling water may be dashed
upon it.

I have said nothing about a repetition of venesection ;
that must be left to the discretion of the practitioner,
whose surest guides are the pulse, the expressions of
pain, and the apparent strength of his patient.

With regard to regimen, the animal ought to be
warmly clothed and have his legs bandaged with flannel,
so as to determine blood to every part of the skin, to be
let loose in his stall, or what is better, in a box, and to
be littered down. His food should be liquid, or, if solid,
soft and very digestible ; such as water gruel, linseed
tea, bran mashes, and arrow root. Corn or hay, under
these circumstances, might aggravate the disease by
passing indigested into the intestines.

The most common termination of enteritis, when it
proves fatal, is in a state bordering upon gangrene ; or
in an intense reddening of the guts, streaked here and
there with dark or black patches. In the human sub-
ject it sometimes ends in suppuration, but I have not
met with any collections of pus in the bowels of the
horse.

* R Pulv. Sem. Sinapis Ibj.

Acct. Calid. q. s. ut ft. cataplasm.
PART II, 2 !■

LECTURE XLV.

Diarrhaa.

DlARRHCEA. in vulgar language called flux, loose-
ness, scorning, &c. consists in copious liquid evacu-
ations from the alimentary canal. I might perhaps, with
more propriety, have entitled this part of my lecture
dysentery; for I believe it is to this form of disorder
that horses, as well as cattle, are more particularly
subject.

Diarrhoea, strictly speaking, originates in an inflam-
mation of the lining membrane of the small intestines,
whereas dysenteiy consists in an inflammation confined
to that of the large, and principally to the colon. I
think that we, who are acquainted with the structure
and functions of the alimentary canal, need not be at a
loss to explain why the horse, and many other gramini-
vorous animals, should rather have dysentery than di-
arrhcea, and more particularly why the former should,
in whom we know that the disorder too often owes its
origin to the abuse of purgative medicine. If in my
description I appear to glance at dysentery as it in-
vades the human subject, I wish it to be understood,
that I make no allusion to the contagious nature of
the malady, if such it ever actually assumes ; though

Diarrhaa.

435

this afFection, like many others, may become epizootic
among horses and cattle, where great numbers of
them are exposed at the same time to the influence
of the same exciting causes. Every sheep in a flock
will be simultaneously attacked with the scours; the
effect of pasture, situation, season, &c. but not of
infection or contagion ; for if they be turned with others
in a place remote from the influence of the exciting
causes, they will not communicate the disease, but, on
the conti-ary, speedily get well of it themselves.

Horses, like cattle, grazing in marshy pastures dur-
ing the cold season, or exposed in particular situations,
become subject to dysentery ; not having been in the
habit however of seeing the disease thus propagated, I
can offer none but general remarks upon this species of
it at present. For the majority of the cases of flux that
are brought to us we are indebted to the groom, the
farrier, and the stable-keeper, who used to kill many
horses formally by literally purging them to death.
Thirty years ago, an ounce and a half or two ounces
of aloes, occasionally combined with one or two
drams of calomel, composed the common purge ; and,
even now, among these people, nine, ten, and eleven
drams are by no means unusual doses. Young horses,
purchased at the country fairs, that have been previ-
ously pastured perhaps, arrive in the metropolis after a
journey of many days, which has pulled them down in
condition and debilitated them: a few days — ay, pro-
bably the very next day, after their arrival, they are all
p/ji/s/cec?— they have given to them indiscriminately
doses of aloes every one of which would be sufficient to
purge two of them ; the result is, that the hght-carcassed
irritable subject is carried off" at once by super-purga-

2 F 2

436

Diarrhota.

tion, while another or two may linger in miseiy anil
pain from a dysentery that will end in gangrene and
death, or be rendered more speedily fatal by the doses
of opium, or some other powerful astringent, which are
so perniciously resorted to on these occasions. There
is another, not uncommon cause of this disease, and
that is, continued and excessive exertion. After hav-
ing been hard ridden for many hours, a horse will
often express irritation in the bowels, by frequently
voiding his excrement, which will be found to be enve-
loped in a slimy or- mucous matter ; or this matter,
which is no more than the intestinal secretion, may be
discharged by itself, and in that state, from its being
supposed to be fat melted by the heat of the body, is
by the farriers called molten grease, under which head
are to be found in many works on farriery the most
absurd accounts of it : this variety I believe to be one
in which the diseased action extends through the small
intestines. I do not deny that vicissitudes of tempera-
ture may produce dysentery, but I cannot help thinking
that cases of it are comparatively rare. That particular
kinds of food, more especially those of a green and
succulent nature, will occasionally excite a flux, is
well known to us all; indeed, the most speedy and
effectual way of producing it, would be to feed a horse
on green meat, and put him to hard work. This dis-
order, for aught I know, may now and then proceed
from some alteration either in the quantity or quality of
the bile ; this however is but a speculative opinion of
my own ; I have no recollection, nor at present any
record by me, of such a case.

I have said that flux in horses more commonly par-
takes of the nature of dysentery than diarrhoea ; my own

Diarrhcea.

437

dissections, as far as they have gone, bear me out in this
assertion ; independently, however, of such proofs (which
by the bye are the only ones worthy of our reliance) a bare
consideration of the exciting causes would incline one
to a belief that this opinion was correct. Aloes, we shall
find, acts principally upon the large intestines ; and
hard riding appears to induce purging, either by hurry-
ing the alimentary matters, before they are sufficiently
digested, into the large guts, where they ferment and
create irritation, or by causing direct irritation during
the act from unnatural friction and over- excitement in
the bowels. The comparative importance of the large
guts in fecation, and the length of time the aliment
remains in them, may also assist us to account for
their greater liability to this disorder.

In treating this malady, whether we suspect its
chief seat to be the small or the large intestines, of
which we may probably form pretty accurate notions by
informing ourselves of the apparent exciting causes,
paying close attention to the symptoms present, and
often inspecting the excrement, we are to bear in mind
that, in generality of cases, it is an effort of nature to
get rid of some offending matter from the alimentary
canal, which has excited more or less irritation, in-
flammation, or ulceration there. This being the case,
the indications in the treatment are three :■ — first and
chiefly, we must undertake the expulsion of the noxious
matter ; secondly, we have to moderate the consequent
irritation and inflammation ; thirdly, we have to repair
any injury that may have been occasioned by it.
Should an over-dose of aloes have been the cause, we are
to encourage the purgation, (for this is Nature's effort to
dislodge and discharge the offending agent,) and
endeavour to shield the tender villi from its irritant

438

Diarrlma.

properties, by giving the horse plenty of barley water
water gruel, or linseed tea. At the same time we are
to keep within proper bounds any accompanying fever
or other symptoms that may indicate inflanmia-
tion in the bowels, by bleeding, fomenting and blis-
tering the belly, and producing diaphoresis, or an
approach to it, by keeping the skin as warm as possible.
Opium, and astringents and cordials of all descriptions,
are at this period pernicious in the extreme. With
regard to diet, we are to convey as much aliment as we
can in a liquid form, as gruel, &c. Whatever proven-
der is given to the animal should be such as can be
easily digested, and is not likely to run into fermentation.
Grain and pulse bruised may be sparingly fed with.
All sorts of green meat, and I think hay also, ought to
be scrupulously abstained from. But give the animal
as much sustenance in a liquid form as he will take,
and offer it to him every hour in the day. This is the
paly rational mode of treating recent cases, either of
diarrhoea or dysentery : if they be but slight, attention
to diet, and promotion of the discharges, aie all they re-
quire ; if violent and accompanied with fever, the other
means I have recommended, must be resorted to, one
or all of them, at the discretion of the practitioner. In
cases where there is much mucus ejected, or only
scybala covered with mucus, and perhaps blood with it,
the effect of hard riding, we may pursue the same
practice, paying special attention to the introduction of
bland, mucilaginous drinks. When green or succulent
food has brought it on, the animal will derive benefit
from the exhibition of alkalines, and the best is chalk :
this substance is found of so much service to calves
that scour chiefly from its virtue in correcting acidity.
In, these cases, large doses of the hydrag. e creta may

Colic.

439

be tried ; half an ounce or an ounce twice or thrice a
day ; or, what I have given with manifest advan-
tage, small doses of calomel combined with chalk *.
Should the flux continue, though the inflammatory and
irritable state of the bowels has apparently subsided, at
least in a great measure, we may venture upon the use
of astringents ; but even at this period, they will suc-
ceed best if combined or alternated with the above medi-
cines ; for it is not the purging itself that we are to direct
our remedies against, but the cause of it, the inflam-
mation of the alimentary canal and the vitiated state of its
secretions : a want of consideration of this circumstance
has led to much bad practice, which, I do not hesitate
to say, has shown itself more in the treatment of these
cases than of any other that occupy the attention of
the veterinary surgeon. Opium is the best astringent
we can exhibit ; let it be given often and in small doses,
conjoined with chalk f : others however may be made
trial of, such as catechu, kino, 8cc.

Colic.

This disorder, also called spas ws, gripes, cramp, &.c.
consists in a spasmodic contraction of some portion or
portions of the intestinal canal. In my lecture on the
anatomy of this organ, I shewed that it was a muscular
part ; it may therefore now and then, like other muscles,
become the subject of spasm.

The symptoms by which colic is known are very like
those of enteritis ; I trust, however, I- shall be able to

* R Hydr. Subm. 9j.

Pulv. Crete ppt. ^iss.

Syr. Simp. q.s. lit ft. bol. mane nocteque exhibendus.
t Ik Tinct. Opii Jj.

Cretffi ppt. q. s. utft. bol. bis tcrve die exliibendus.

440

Colic.

point out sufficient signs of distinction between them
to safely direct the practitioner in his administration. An
attack of gripes is most commonly quite sudden ; the
malady makes its appearance without any precursory or
even accompanying febrile commotion. The horse is
all at once seized with symptoms of extreme uneasiness
and pain : — he paws, occasionally strikes his belly with
his feet, lies down and rolls over, sometimes rolls upon
his back, in which posture he continues for a few se-
conds, as if it afforded him relief ; suddenly he rises up
again, shakes himself, and casting a doleful look at his
flank, expressive of the agony he suffers, seems to fore-
warn you of the approach of another paroxysm, which
ig commonly more violent than the preceding one. At
the onset, the remissions or intervals of ease are generally
well marked, but as the disorder advances the paroxysms
grow more violent and longer in duration, and the remis-
sions become shorter or are altogether wanting. The
animal is continually rising up and lying down, he sweats
profusely, he heaves at the flank, and evinces by his vio-
lent actions his heedlessness of what is doing about him,
and by his wild, frantic eye, the acute and twitching
pains he feels in his bowels. If the pulse be examined at
the onset, during a remission, but little or no alteration
will be perceptible in it ; but, while the paroxysm lasts,
it is contracted to a thread, nearly or quite imperceptible
and quickened ; and in the season of extreme pain and
agony it undergoes great acceleration. The belly feels
tense ; and costiveness is mostly present. In conclud-
ing this account of its symptomatology, I wish it to be
understood, that spasm is sometimes present as an effect
of enteritis, and now and then itself terminates in that
disease.

Remember then, that of colic fever is neither a pre-

Colic.

441

cursor, nor an early concomitant, i. e. there is little or no
variation of pulse, no antecedent shivering fit, or other
symptom of ill health ; that its approach is not only
quick, but generally sudden ; and that all the symptoms
of disturbance subside at intervals into a state of tran-
quillity and apparent freedom from pain, which they
never do in enteritis. Some insist that the horse rolls
upon his back if affected with colic, but never, or not so
often, when suffering from enteritis ; but, in my opi-
nion, this is too vague and indeterminate a sign, by
itself, to build a safe diagnosis upon : the animal will
roll upon his back in enteritis sometimes, and so he will,
I should imagine, (for I have no case in my mind, at
present, that I could adduce in support of it,) in acute
peritonitis.

That gripes do now and then supervene upon a co-
pious ingurgitation of spring or cold water in hot
weather, or when the animal is himself heated, every
groom can vouch for ; but that it is the result of sup-
pressed perspiration, or of suddenly cooling the surface
of the body when heated, is to me very questionable.
No food is so likely to generate spasm as that which is
disposed to run into fennentation .: during the season
that horses are fed on green meat, I have known the
disease to be epizootic. Aloes now and then excites it
by its irritating effects. Mr. Bracey Clark ascribes
a predisposition to horses to gripes from peculiarities in the
conformation of their alimentary canal, and a consequent
disturbance or suspension of chylification — to the applica-
tion of cold to the surface of the abdomen— and to the
shortness of the omentum and its thinness of adeps,
whereby the guts, particularly the cacum and colon, are
NOT KEPT so WARM OS in animals in which it is of
greater length.

442

Colic.

The proximate cause of colic is spasmodic constric
tions of the small guts ; at least, I have never seen them
in the large. Professor Peall however seems to regard
them also as the seat of spasm ; " for," says he, speaking of
giving clysters, " the spasms of the posterior bowels be
come so violent and rigid, that no ordinary strength is
sufficient to overcome their power." And in another
place, the Professor observes that " clysters are essen-
tially necessary, not only on account of the spasm, and
obstruction in the bowels, but of another dangerous
symptom, also, which is usually a concomitant in these
cases ; I mean spasm at the neck of the bladder, attended
with a suppression of urine." This last is a symptom
that, I must confess, has escaped my observation ; I
shall however for the future direct my inquiries to it :
when present, for I apprehend that it is not constant in
gripes, it becomes a question whether the catheter
ought to be passed. In tracing the intestines of a horse
that has died of this disease, from the stomach to the
ccecum, we find parts of the canal, here and there, ex-
tremely contracted, as if a piece of broad tape had
been lied tight around them : oftentime the contracted part
will be three or four inches in breadth, and only divided
by a sound portion of equal extent from another ; and in
this way I have seen many of them in the same bowels*.
So readily is spasm subdued or removed, in the gene-

* As the cases of gripes published by Mr. Clark do not accord
with the views here taken of the disorder, I shall subjoin an ac-
count of the appearances they presented ^os? mortem.

The first is that of a horse who was seized witli gripes during the
night, and who died of it at 9 a. m. " I was desirous," says Mr. C.
" to sec him opened, and found a most extraordinary titickening
curd inflammation of the cwcum, as though a general rupture of tlie
vessels and membranes of this intestine had taken place, and tlic

I

Colic.

'443

rality of cases, that there is scarcely any horse-dealer,
farrier, or head groom, that would deign to receive in-

blood was lodged between its coats ; the inside lining of the intes-
tine was almost black, the outside comparatively but little in-
flamed. The intestine itself contained a great deal of ill digested
and ill masticated food, of beans, oats, and ill chewed hay, mixed
with a bloody water, or red serum, which had probably been thrown
out from the distended arteries and vessels which at length were
ruptured by the inflammatory action. The small intestines were
not much affected ; here and there a patch of inflamed surface."

" The second case I select" was one in which " the symptoms
were the most violent, and the pain and inflammation went on in
the most rapid way I had ever yet seen." The horse was taken ill
at Islington and lived six hours after his return to London, during
which time opium, fomentations, clysters, &c. were administered in
vain. " We immediately opened him, and found the colon and cascum
highly inflamed, and an immense quantity of ill chewed, undigested
food within, and a large quantity of greenish red water, and some
air. Here the cause evidently appeared to be indigestion ; and from
the horse-keeper I understood he was a very voracious feeder, and had
been several times seized in this way before, but not so violently."

In a third case which lived " longer by seven or eight hours"
than either of the preceding, Mr. C. " found that the inflammation
was Twt confined to the large guts, but the ileum and jejunum also
were sufferers ; some balls of dung were found about the middle
of the ileum that had the appearance of having undergone a strong
compression, and some of these balls appeared externally red witli
blood. The commencement of the colon contained a large portion
(two hats full) of almost dry undigested grain and hay." — "I also
observed a gangrenous patch, as large as my hand, on ^the colon,
the onli/ instance I recollect to have seen of it in the horse. All the
internal surface of the intestine was like a mass of red sponge, drenched
and filled with dark grumous blood."

I agree with Mr. C. that in these cases " indigestion was cer-
tainly the primary cause of the mischief," and it is evident
that the mischief itself was inflammation, and as such they do
not come under the denomination of gripes, according to the accepta-
tion which I hold of that word. I tnke gripes, colic, and spastns of the

444

Colic.

struction on the subject, or that has not some nostrum of
his own of infallible efficacy. And, confining my obser-
vation to a genuine case of colic, they almost always
succeed : for, the fact is, in many of the ordinary cases,
whether any thing or nothing be done, the horse will,
after having rolled and kicked in. pain for an hour or so,
and procured an evacuation or two, spontaneously recover.
So that whether we give gin and pepper *, as they do in
some parts of the country ; or oil of turpentine, as is re-
commended at the Veterinary College-j- ; or Mr. Bracey
Clark's prescription, tincture of pimento J ; or tinc-

intestines, to be one and the same disorder : without spasm I have no
conception of what gripes is. If we suffer ourselves to be led away by
the vulgar — the farrier's use of the word gripes, according to which it
is indiscriminately applied to every horse that paws, lies dowTi, and
rolls and kicks about from pain, we shall find in the course of our
practice that we have made gripes a very comprehensive order, under
which we must not only range various kindred genera, but diseases of
an opposite nature and tendency, affecting parts that have no con-
nexion whatever, either in a healthy or morbid condition. Dyspep-
sia, colic, enteritis, peritonitis, hepatitis, nephritis, cystitis, in short,
almost every acute and painful affection of the abdominal and pel-
vic viscera, as well as pleurisy and peripneumony occasionally, are
all gripes to a farrier. It is lamentable and highly derogatory, that
the profession is yet without a systematic nomenclature. Bracey
Clark's Essay on the Gripes of Horses.

* Almost any pungent aromatic, and most of the diffiisible
stimulants, will answer the purpose quite as well, I believe.

t R Sprts. Terebinth, gij. adjiv."
Aquse Tepid. Ibj. M. f. haust.

I Infuse Ibj. of pimento in Ibiss. of water and tlie same quantity
of spirit, for several days; strain the infusion, or let it stand until
it be required for use. Give four ounces of it, mixed witli common
or peppermint water, immediately, and repeat the dose in half-an-
hour, and every succeeding hour until the symptoms be relieved. —
op. sit. sup.

Colic.

446

ture of opium, which I myself prefer, the spasm will
subside; though undoubtedly much quicker from some
of these remedies than from others. And it is a duty
incumbent upon us, to administer with as little delay as
possible to the extreme sufferings of an animal thus
affected : and for this purpose I recommend that three
ounces of laudanum be exhibited in a pint of peppermint
water* . My father is in the habit of prescribing two
ounces of oil of turpentine in combination with half
the quantity of the tincture of opium ; and I am very
much inclined to think that however efficacious the tur-
pentine may be of itself, its operation, as an antispas'
modic, is accelerated and rendered more permanent by
the addition of opium. Professor Peall has, in a
laudable tone of humanity and sympathy, censured the
practice of compelling griped horses to take exercise ;
but, though I am always inclined to be led by sentiments
of compassion, which, as far as the temporary sufferings
of the patient are concerned, are here in perfect unison
with his, I must now restrain them lest they get the better
of my judgment. For it is a practical fact, that many
horses thus affected that are stimulated to take a brisk trot,
are found, on being put into the stable again, to have ex-

* I have also given the following formula with success, and I in-
tend to follow up the practice, as one that combines the most de-
sirable ultimatum in these cases of opening the bowels after it has
relieved the spasm, and thereby of counteracting the tendency to
inflammation.

R Decoct. Aloes ^xij.
Tinct. Opii ^ij.
Ol. Carui Jft. M.

The formula to make the decoction will be found in a note, at
page 194, Part I.

446

Colic.

perienced so much relief from it that another paroxysm
has not recurred, though the fits were incessant prior to
their having been taken out. The common practice is to
give the animal his drench, and then direct the groom to
get upon him and trot him briskly for a few minutes,
after this to walk him, and then renew the trot. The
drink ought to be repeated every half-hour. While the
horse is in the stable, the belly should be well rubbed
with a hard brush, or with the handle of the broom, or
any suitable thing that happens to be on the spot.

We shall seldom have occasion to repeat the drench
more than twice or thrice ; for, what may be expected
in the majority of these cases, if the spasm be not re-
moved in the course of a few hours, is the accession of
inflammation ; which, as I stated before, may either su-
pervene upon spasm, or be the fore-runner and producer
of it. Knowing this then, we should narrowly watch the
symptoms, and be on our guard against the approach of
enteritis, in order that we may lose no time in flying to
another class of remedies. If e.g. we find the pulse
getting up, and increasing in perceptibility and strength,
we had better, without delay, take away a large quantity of
blood ; indeed many practitioners bleed in cases of sim-
ple gripes, and although the practice canuot be justified
so long as stimulants and opium are deemed requisite, it
is far from being condemnable ; for to use their own argu-
ment, " it can do no harm and may be productive of
good :" venesection itself being an antispasmodic. But
should inflammation have manifested itself, we are im-
mediately to betake ourselves to that catalogue of reme-
dies recommended in enteritis, to the exclusion of our
antispasmodics ; for, if any symptoms of spasm still
remain, we must look upon them as consequent upon in-

On Calculi, &jC. found in the Intestines. 447

flammation, and to the abatement of that devote all our
subsequent measures.

It is the common practice with those who rest content
with the antispasmodic effects of the oil of turpentine,
to give a few balls composed of solid turpentine — the
terebinth, vulg. after all symptoms of spasm have va-
nished, in order to prevent a relapse. With equal rea-
son, it strikes me, might we ourselves take mercury to
prevent the recuiTence of the venereal disease, or cu-
bebs pepper to guard against gonorrhcBa ; unfortunately
for us, as well as for our patients, that which cures has
not the virtue of preventioh, otherwise the consumption
of medicine would probably be much greater than it now
is, and the prevalence of disease considerably less.

On Calculi, and other Concretions, found in the Intestines.

Calculous, or other extraneous matter now and
then collects within the guts ; we commonly find it in
the large — in the ccecum or colon. The shape and ap-
pearance of intestinal calculi, which vary much, will de-
pend on the nature of the foreign substance taken in,
and the situation in which it afterwa:rds collects ; there
is one other circumstance however which will frequently
regulate their shape, and that is, the figure of the central
piece upon which the earthy matter is deposited : e.g.
if the nucleus be round the calculus will be round, ge-
nerally speaking ; and we have a calculus of the exact
shape of a horse-nail in consequence of a stub * being its
nucleus. Others, however, do not appear to possess
any nucleus at all ; or, at least, if there be one, it is of

* Nails that are useless in shoeing, from having lost their points,
are called stubs.

448 On Calculi, i^c. found in the Intestines.

. the same composition as, though firmer than, the sub-
stance of the calculus itself ; and many of these calculi
take on the general figure of the cavity in which they
happen to be lodged : such found in the colon, unless
they be of very large size, are lobulated — shaped ex-
actly like so many balls of dung. The concretions com-
monly met with, are of an earthy composition, strati-
form, like the concentric lamellae of an onion, very
hard, and bear some resemblance in their external ap-
pearance to a common pebble ; others are soft and of
a less compact texture ; and a third kind appear to
be composed of indurated faeces, and of hay, com,
straw, &c. imperfectly digested, all which seem to have
been agglutinated together by the intestinal secretions :
they are denominated dung-balls ; and indeed very pro-
perly so, for they contain but little, if any, other than
stercoraceous matter. A fourth kind are found, but
they are not common, composed principally of hair ; they
are oftener seen in cows, those animals being in the
habit of licking their coats. Calculi vary no less
in magnitude and color than in shape and composi-
tion. [Some are of very large size : we have them from
eight inches in diameter to the diminutiveness of the
smallest pebble ; and from forty ounces in weight to as
many 'grains. Most of our specimens are white, some
red, many incline to the color of the dung, and others
are of a very dark dirty hue. Why the horse, beyond
other animals, should be so subject to have concretions
of this nature, may be readily answered, by saying,
because no other animal, that we know of, swal-
lows so much calcareous matter. Horses under cer-
tain circumstances will actually lick up and eat the
earth- they tread upon :— when they are piquetted at

On Calculi, 8fc. found in the Intestines. 449

camp, and are only allowed a sparing ration of proven-
der, they will frequently, from craving after food, not
only tear up every dirty weed within reach, but eat
the roots and then the dirt itself. There are other
horses, who when turned out, although they are well
fed, will pick up various indigestible substances they
find in their range, gnaw the fences, swallow pieces of
wood, or even nails, all which may afterwards become
the nuclei to calculi. Independently of all this, howe-
ver, we are to remember that the horse, although a
nice-feeding animal in general, does actually take in
much extraneous matter, such as dust, small pebbles,
&c. with his provender, particularly when he is fed
upon com not well cleaned or sifted, and certain inferior
kinds of hay : whence it arises that millers' horses are
very subject to calculous collections, who are fed upon
meal, which, I believe, often contains small particles of
the grind-stones. The lodgement of these concretions
within the intestines may operate in producing death
in three or four different ways. They may excite spasms
in the guts, and thus occasion an irrelievable attack of
colic ; or they may, by irritation^ excite enteritis, and
thus prove fatal ; or they may obstruct the passage of
the alimentary matters, and produce inflammation and
gangrene of the gut. Of this last we have an excellent
specimen in a preparation of the colon ; and Mr. W.
Goodwin has met with an instance of it in the small
intestines.

I know of no symptoms by which the presence of a
calculus in the intestines is indicated with any degree of
certainty ; unless perchance we should detect any cal-
careous matter, or small stones, mingled with the fseces ;
should we suspect, however, the presence of one, we

PART II. 2 o

450 On Calculi, S^c. found in the Intestines.

may, with some prospects of dissolving it, give large
doses of either acids or alkalies, according to the sup-
posed composition of the calculus, and follow them up
with occasional doses of purgative medicine. Long and
irrelievable constipation of the bowels is the natural con-
sequence of an obstructed passage, and such a symptom
may lead us to suspect there is some concretion in it,
but of what nature we have no means of ascertaining.
Mr. King, V. S. at Stanmore, related a case to me of
a horse that passed nothing per anum for thirteen days :
having reason to believe that this arose from some ster-
coraceous collection, and seeing that the animal must
inevitably die unless it were removed, he made an open-
ing into the flank, introduced his hand, and, feeling a
hard swelling through one of the guts, broke it down
by compression. This operation was followed by co-
pious feculent discharges : but the animal had previ-
ously sunk, past recovery.

LECTURE XLVI.

On Worms.

Having proceeded thus far in my observations on
the diseases of the stomach and intestines, I am called
on, in conformity with custom, to take up the consider-
ation of the subject of worms ; whether as a disease, or
not, will best appear in the sequel of this lecture. By
pi'esumptuous dabblers in veterinary practice, they have
ever been, and are still regarded as destructive vermin,
a notion to which we may refer those vulgar prejudices
of the present day that associate an utter dread and ab-
horrence with the idea of worms crawling alive within
an animal's bowels ; which prejudices have in no few
fatal cases been made the ready instruments of the con-
sciously ignorant farrier in repressing the inquisitive-
ness of his employers, and putting an end to all further
inquiry after the cause of his unfortunate patient's
death.

Four kinds of worms have been seen within the bow- .
els of horseg : viz. the cestrus or bot ; the lumbricus teres
or long white worm ; the ascaris or small, thread-like
worm ; and thie iania or tape worm.

2 G 2

452

Bots.

The bot, an animal whose nidus or natural habitation
appears to be the stomach, is so well known in its ge-
neral characters to eveiy one who possesses any acquaint-
ance with horses that 1 do not conceive that a description
of it is wanting here : I shall therefore commence with
its natural history. And here I beg to offer my small
tribute of praise for the acknowledged services rendered
to the art, in this department of science, by that learned
member of it, Mr. Bracey Clark, to whose pleasing
essay on the subject I am indebted for this part of the
present lectui-e.

Mr. Clark has exposed the erroneous view that was
formally taken of the bot in regarding it as a worm ; he
has demonstrated to us that it is the larva or caterpillar
of a particular species of the genus oestrus or gad-fly. He
has particularized three species of bots ; they however
are rather distinguished from one another by inci-
dents connected with their natural history than by any
specific corporal characters. The first is the oesti-us equi
or large spotted horse-bot, the most interesting of the
three to us in this country ; the second is the oestrus
hemorrhoidalis or fundament bot ; the third, Mr. C. has
named the oestrus veterinus or red bot. Although I shall
make many extracts as I proceed, my limits will by no
means admit of my regularly accompanying this indus-
trious author through his curious details ; and even if
they did, I should still conclude my remarks, by pre-
scribing for the veterinary student the gratifying task
of perusing this small volume himself*. Speaking of

* An Essai/ on the Bots of Horses and other Animals. By Bbacey
Clark, F. L. S. and V. S.

Bots.

453

the (ESTRUs EQUi, Mr. C. says, " As it is necessary to
break into the circle of its history at some point, I shall
begin with an account of the egg, and its deposition
upon the skin of the legs of the horse, which is done in
the following remarkable manner: — When the female
has been impregnated, and the eggs sufficiently matured,
she seeks among the horses a subject for her purpose,
and approaching him on the wing, she carries her body
nearly upright in the air, and her tail, which is length-
ened for the purpose, curved inwards and upwards : in
this way she approaches the part where she designs to
deposit the egg ; and suspending herself for a few se-
conds before it, suddenly darts upon it, and leaves the
egg adhering to the hair : she hardly appears to settle,
but merely touches the hair with the egg held out on
the projected point of the abdomen. The egg is made
to adhere by means of a glutinous liquor secreted with
it. She then leaves the horse at a small distance, and
prepares a second egg, and, poising herself before the
part, deposits it in the same way. The liquor dries,
and the egg becomes firmly glued to the hair ; this is
repeated by these flies till four or five hundred eggs are
sometimes placed on one horse." The parts chosen for
the deposition of these eggs are those liable to be licked
by ihe tongue ; the inside of the knee is a favorite spot,
and next to this, the side and back part of the shoulder,
and less frequently the extreme ends of the hairs of the
mane. Now the common notion is, that the ova are
licked off the skin, and thence carried into the stomach;
but Mr. C. observes, " I do not find this to be the case,
or at least only by accident ; for when they have remained
on the hair four or five days, they become ripe, after
which time the slightest application of warmth and moisr

454

Bots.

ture is sufficient to bring forth in an instant the latent
larva. At this time, if the tongue of the horse touches
the egg, its operculum is thrown open, and a small ac-
tive worm is produced, which readily adheres to the
moist surface of the tongue, and is from thence con-
veyed with the food to the stomach." And it appears,
that the irritations of the common flies is the instigation
of the animal's licking himself ; not however that this
is absolutely necessaiy, for " a horse that has no ova
deposited on him, may yet have bots, by performing the
friendly office of licking another horse that has." The
larva or worm, being hatched and lodged in the stomach,
immediately clings, by means of its tentacula — two dark
brown hooks, between which is its mouth — to the
cuticular coat, which they pierce, though they never
insinuate their points into the muscular or sensitive
tunic beyond it : in this manner, so pertinaciously
does the bot adhere that in our attempts to unhitch it,
it will frequently suffer its hooks to be broken, or even
its body severed, rather than quit its hold. Now and
then, but I believe very rarely, they are found hooked
in the villous coat ; these however are nothing more than
stragglers, bots probably that had, on their arrival in
the stomach, been hastily carried with the aliment into
its vascular part, before they had the power of fixing
their hooks into the cuticular. Here, then, is a fact
which ought to stifle our apprehensions about the pain
and irritation that these animals are said to occasion :
how they can cause either, when they are fastened to an
insensible part, to a part as devoid of feeling in itself as
the very hoofs are, I have yet to learn. The bot thus
transported about the latter part of the summer, while
horses are at grass, remains in the stomach through the

Bots.

453

winter, until the end of the ensuing spring, when, being
at the consummation of this s'tage or form of existence,
it spontaneously disengages itself, and passes with the
chymous matters into the intestinal canal ; where its
stay probably is but short, since it now lies loose
among the alimentary matters, and is eventually cast out
from its animal abode with the dung. Now, it has long
been a question, and one which is not yet set at rest, on
what these worms subsist in the stomach. Mr. C. sup-
poses their food to be the chyme, which, (he says) being
nearly pure aliment, affords probably but little excre-
mentitious residue. I do not however believe that nearly
pure aliment — what we understand by chyle, is found in the
stomach, much less in the cuticular part of it, where, as
far as I have observed, the food itself remains unchanged
even into chyme. But, suppose they were surrounded
by chymous, or even chylous matter, their mouths, in-
stead of floating in it, are opposed to, if not in contact
with, the lining membrane of the stomach, and conse-
quently not conveniently placed for such imbibition: in
fact, their mouths must be, I should imagine, enveloped
and concealed by mucus, as abundance of that fluid is de-
posited upon the surface of the alimentary mass, to sheathe
the stomach from mechanical irritation. For myself, I feel
inclined to think that this mucus constitutes their food ;
and it is one probably that possesses little or no excre-
meutitious matter, since it is itself re-absorbed in many
parts of the body ; but what favors this opinion is, that
there are bots in the sinuses of the head, in the skin, &c.
of cattle, which can have no other sustenance than the
secretions of those parts, a fact that Mr. C. himself ad-
mits ; and that worms in the intestines of animals are
nourished in the same way, is rendered highly probable

456

Bots.

by the existence of the ascaris in the colon and rectum —
guts that contain little or nothing else but what is innu-
tritious.

About the month of June or July it is, that the bots,
having left the gastric region and been transported with
the aliment through the windings of the intestinal tube,
are discharged with the fasces ; and at this period it is
that people discover that their horses (particularly those
that have been at grass the preceding autumn) have
worms ; to get rid of which vermifuges all at once come
into general requisition; but if these well-meaning peo-
ple will only have a little patience, these imaginary
plagues will soon quit the bowels of their horses of their
own accord. The larva, being ejected, lies not long ex-
posed upon the ground, or concealed in dung, but quickly
dries up and shrinks into the state of chrysalis or grub, in
which torpid condition it continues for a few weeks ; aj
the expiration of this lime, " the superfluous moisture
being removed, and the parts of the future insect being har-
dened by drying, it bursts from its confinement, and the fly
appears making its exit at the small end." — " On quitting
their shell" (male and female) says Mr. C. (from whom I
am now citing) " they in a few hours become dry, take
wing, and then seek their mates. The female being
impregnated, searches for a proper subject among the
horses, performs with great solicitude and care her office
of depositing the eggs upon the legs of the horse, in the
manner we have already stated, thus completing the
wonderful round of its operations and history."

The insect of the cestrus hemorkhoidalis or
fundament hot, whose manner of depositing eggs, says
Mr. C. has never been described, or known before,
chooses the lips of the horse for this purpose, " which

Bots. 457

is very distressing to the animal from the excessive titil-
lation it occasions; for he immediately after rubs his
mouth against the ground, his fore legs, or sometimes
against a tree, with great emotion ; till the animal at
length finding this mode of defence insufficient, enraged
he quits the spot, and endeavours to avoid it by galloping
away to a distant part of the field ; and if the fly still
continues to follow and teaze him, his last resource is in
the water, where the testrus never is observed to pursue
him. These flies appear sometimes to hide themselves
in the grass, and as the horse stoops to graze they dart
upon the mouth or lips, and are always observed to poise
themselves during a few seconds in the air, while the
eggis preparing on the extended point of the abdomen." —
" The larva or grub of this species inhabits the stomach
as the former, generally adhering to the white lining, and
is disposed promiscuously in dense clusters after the
same manner; they may however be distinguished from
them bi/ being in general smaller, longer in proportion to
their bulk and rounder ; and I have thought, of a duller
red, or more inclining to a white, than those of the
equi, for they differ in appearance in different subjects."
These bots quit their habitation in the same season of
the year, but are rendered remarkable by their *' sticking
more or less within the verge or opening of the anus,
adhering to its soft lining, and producing considerable
irritation. Indeed 1 once well remember," continues
Mr. C, " being on a tour of pleasure in' the Isle of
Wight, and experiencing much annoyance from these
larvae. The little horse I had hired for the journey be-
came so lazy and unwilling to go on, and moved so
awkwardly, that I could not keep pace with my com-
pany, and I was at a loss how to proceed ; but on casu-

458 Bots.

ally taking up the tail, I discovered three or four of these
insects hanging to the rectum, and their removal in-
stantly proved a cure." Its change to the chrysalis
state, and further transformation into that of insect,
which happens in about two months, is similar to what
befals the oestrus eqni.

Of the CESTKUS VETERiNUS, or red bot, so desig-
nated by Mr. C. in preference to retaining the epithet
nasalis, which conveys a false notion of its habitation,
the same historical detail does not appear to be made
out, for this author commences his account of it by
saying, "The mode of this insect depositing its eggs or
nits, is at present unknown. By watching for them on
the commons in the warm days of the sixth and seventh
months (July and August) it might be detected, I appre-
hend, without very great difficulty. They perhaps
deposit them about the lips or legs, as the former species.
The larva of this species is also not certainly known.
That it inhabits the stomach as the two former species
there is little doubt ; and 1 have taken considerable
pains to search for it at the slaughter-houses, and have
found a species in the stomach which widely differs from
the'equi and hemorrhoidalis, and which I presume may
be the larva of this : though it is possible there may be
a fourth species inhabiting the stomach of the horse, in
which case it may be still doubtful, that I do not posi-
tively assert it to be this larva belonging to the vete-
rinus."

" This larva, if it is the veterinus, may be known
from the two preceding species, being smaller, of a more
tapering or oblong Jigure, and the segments mot e detached
and rounded, shining, smooth, and of a pellucid red or ruby
colour, more particularly at the tail or obtuse end."

Bots.

459

After having described a fourth species, or what he ap-
prehends to be so, from some peculiar characters it pos-
sesses, Mr. C. asserts that he once found the real
chrysalis of the veterinus in the neighbourhood of
Worcester, under some horse dung, a drawing of which
he gives from memory.

The ovum, nit, or egg of the bot then, it appears,
being deposited some time in the autumn upon the hair,
gets licked by the tongue, by the heat and moisture of
which it is instantly hatched, and its larva liberated and
absorbed. With the food the larva is conveyed into the
stomach, where it fixes its residence for the winter by
insinuating its tentacula into the cuticular coat. In
the spring of the year it withdraws its hooks, descends
from the stomach into the intestines, and is carried along
with the alimentary mass to be expelled with the faeces.
Its exposure in the dung is quickly followed by its desic-
cation and contraction into the state of chrysalis, from
which, in about two months, it undergoes its last meta-
morphosis into the insect called a gad-fly.

We now come to what our author calls the " pro-
bable EFFECTS OF THE GASTRIC OESTRl UPON ANI-
MALS," a subject replete with interest, and one that
presents a wide field for speculation, both to the phy-
siologist and natural historian. By a train of argument,
interspersed with some (that appear to me to be) singular
notions, Mr. C. endeavours to shew that bots exert a
salubrious influence in the stomach of the horse by pro-
moting digestion, acting as what he calls vellicatories,
like local stimulants and detractors, on the principle of
counter-irritation. 1 cannot however acquiesce in these
hypotheses, much less admit what this learned writer
has adduced in support of them. That " children of

460

Bots.

cachetic habits breed worms faster than healthy chil-
dren, which may tend to suppress or moderate the
disease they incline to," is an opinion that obtained
with our predecessors in physic, but one which I should
apprehend would find few or no advocates among the
physicians of the present age ; and that sheep in low
damp situations, 6y being infested with worms, may he
presemed from toorse disease, seems to me to be equally
irreconcileable with the sound physiology of the day.
Wliat LiNN^us taught, " that lice, by gnawing or irri-
tating the skin of the head, excite a sort of running
sores among boys kept in filthy work -houses, or con-
fined places, and become strumous or swoln by the
confinement, hi/ this excitement are preserved from coughs,
wheezings, blindness, epilepsy, S^c." might have been
perfectly consistent with the pathology of his time, but
that Mr. C. should repeat it to strengthen his opinions
in this more enlightened age of medical science, I must
say I feel some surprise. And when, in proceeding, I
find it stated that it will not be easy to discover how
far the access of murrain in cattle, glanders, faroy, S)X.
in horses, may be prevented, and moon-blindness, inflam-
mation of the lungs, spasms, splints, 8fc. in any degree
checked or subdued by the presence of these local stimuli —
and in another place, that his horse became fatter in conse-
querjce of having had administered to him about three dozen
of bots' eggs, and that the nasal farcy gleets of horses were
cured by stimulation to the STOMACH,y70/« the ex-
hibition of two powerful astringents, cantharides and sulphate
of zinc, I must add that I depart toto coilo from the views
here taken of the effects, healthful or hurtful, of these
little animals ; and I venture to be the more explicit in
my opinions of these remarks, as Mr. C. says he shall

Bo^s. 461

not be tenacious about the permanency of the founda-
tion they may furnish materials for.

But let us inquire how the operations are to be con-
ducted to which Mr. C. attributes such a variety and
number of beneficial effects — how bots can promote
digestion, and excite irritation and issue by velli-
cation. We must not forget that bots are attached
to a part of the stomach that does not perform any pro-
per digestive function, and that all stimulants or other
substances promotive of digestion, must be applied to
the vascular part, the only veritably digestive surface,
or, it is obvious, they can have no such effect ; more-
over, the cuticular portion of the stomach being inor-
ganic, how can any thing like a determination of blood
or issue be produced in it? Indeed, I do not see with
Mr. C. how they can perform the office of stimuli at all»
unless it be that, by some motion they are capable of,
they may have any such influence upon the mucous folli-
cles placed in abundance under the cuticular coat ; but
then, again, we are not sure that this secretion is
necessary to digestion ! Thus far however, we per-
fectly coincide in opinion — " that the perfect health
they (horses) enjoy with them, (bots) is proof sufficient of
their innocuous nature and harmlessness in a general
way *."

Mr. C. concludes his interesting account of the bots
found in horses with some observations on the most
effectual mode of destroying them. He observes, (and

* I have heard Professor Coleman say, that he knew of one
case where bots appeared to have destroyed ; for, after death, the
coats of the stomach were found eroded in places, as well as the
diaphragm, and some of those animals had made their way into the
cavity of the chest.

462

Bols.

this observation should be iinpiiiited upon our mind)
that — " At the natural annual period of their transforma-
tion they come away readily enough of themselves ; and
if it happens at the time that any medicine has been ex-
hibited, it is considered as proof enough of its efficacy,
and mistaken for the consequence of it : so easy is it
to draw wrong conclusions. Neither opium nor tobacco
given for several days have any effect upon them, as I
have witnessed by opening the stomach after the death
of such and finding them lively and well. We can, it is
true, force the poison down the horse's throat, but we
cannot afterwards get it into the throat of the worm,
who is placed in his own element, and can refuse the
food that does not suit him. Truly is it therefore dif-
ficult to destroy them by means of poison thrown into
the stomach." — " The wisest measure," continues our
author, " for securing animals from their effects is to
prevent their propagation or access, and their habits
expose to us an effectual mode of doing this. The
eggs of the oestrus equi, which are very conspicuous
on the knee, the mane, and the sides of the horse, may
be washed off by a brush and warm water, or still more
effectually removed by a pair of scissars. The same
may be done for the hemorrhoidalis from the lips and
beard."

" The other species being smaller, more i-are, and
probably less troublesome, require therefore less our
consideration."

" In respect to the hemorrhoidalis also, where horses
have been much out at grass the preceding year, they
should occasionally in the warm months of the next
summer be examined for them, when they will be found,
as we have already stated, hanging to the extremity of

Bots.

463

the rectum, and should be removed by the fingers. The
destruction of a single one at this season of the year is
not only the death of an individual and its effects, but
the almost certain destruction of a numerous progeny ;
it is also useful in preventing the irritation which the
spines of the bot occasion to the anus, which irritation
becomes veiy distressing to the animal if he is used on
the road, occasions him to move awkwardly, wriggle
himself about, and to be sluggish, and though beaten
severely he soon relapses again into his awkward man-
ner of going ; which as this happens generally in warm
weather, is most commonly attributed to mere lazi-
ness."

It has been conjectured, that bots might prove ser-
viceable to the animal by aiding the cuticular coat in
the trituration of the food ; but as I do not think that
any proof or incontrovertible argument has been ad-
duced in support of such a power being possessed by
the stomach of the horse, and as I shall have occasion
to discuss the question in another place, I do not con-
ceive it necessary to reply to this conjecture here.

That Nature should have created an animal, and de-
signed it as an inhabitant of the stomach of another
animal, without some good, but, I suspect, unknown
end, I think, in unison with others, highly im-
probable, and irreconcileable with other beautiful
and more-readily-explained operations : I am however,
for my own part, unable to draw up the curtain which
is here interposed between fact and design.

Taking it for granted that bots in some way or other
do good rather than hurt, surely we cannot be solicitous
about removing them ; for, though we cannot demon-
strate their beneficial influence, we can, from all the cir-

464

Bols.

cumstances we have a knowledge of regarding them,
boldly assert, that they are in nowise injurious. Howbeit,
we cannot persuade the world so ; and therefore we
must be prepared to meet the complaints of them who
come to us about June or July, and say that " their
horses have worms, which must be got rid of," with a
remedy for that purpose. Should any other malady
exist at the same time, no matter what, its origin wiU
commonly be traced to the presence of these mischievous
vermin. In all works on farriery, you will find some
recipe extolled as a vermifuge ; which, unless it con-
tain a purgative ingredient, you may at once expunge
as inefficacious ; for we know of no medicine that has
the power of destroying bots in the stomach, and if we
did, are we sure that, even when dead, they would be
detached from its cuticular coat : though, if they were
in its vascular part, they would be subjected to the
action of the gastric juice. No medicine therefore, not
even a purge, can operate as a vermifuge but at a cer-
tain season of the year ; when, as I said before, if you
will but suspend its exhibition for a while, the worms
will all readily pass away without your assistance. But,
if we must prescribe something as a vermifuge, we
have no other resource than a common purge : a dose of
aloes is all that is required, though it is usual to com-
bine it with calomel *, which will certainly render it
more active, and herein resides all the (supposed) spe-
cific virtue of the latter medicine as a vermifuge.

* R Ext. Aloes Vulg. 3vj.
Hydr. Subm. 3j.
Pulv. Zinzib. 31 J.
Syr. Simp. q. s. ut ft. Bol.

465

The Lumbi'icus Teres.

The lumbricus teres or long lohite tvorm, is now and
then found in the bowels of the horse after death ;
though it seldom or never happens, unless per chance
one be voided, that we have any knowledge of its ex-,
istence during life. This worm is white, round, sharp-
ll pointed, and several inches in length, and in form resem-
bles the common earth-worm. They inhabit the small
intestines, mostly the jejunum and ileum, are but
seldom seen in the large guts, unless medicine . have
been given, and never, I believe, have been detected
ll in the stomach. They are more frequently found in the
dog than in the horse. I have read strange accounts of
the injuries sustained from the presence of these
worms in the bowels, but so inconclusive are they,- in
consequence of the remedies employed having been of a
more destructive tendency than the worms themselves,
that I cannot determine what importance should be at-
m tached to them. I have not seen nor heard of any cases
of this description ; at the same time, I do not meani to
assert that they never occur in practice, though I believe
them to be exceeding rare. Apprehensions have been
entertained by some of their staiving the horse to death;
by a consumption of chyle : we have no more reason,
however, to believe that these worms feed on chi/le than
we have of the bots being nourished hy chyme ; on the
contrary, I should argue, on nearly the same grounds,
that their aliment might be the intestinal secretion.

I know of no symptoms on which we can rely that in-
dicate the presence of these wornjs ; emaciation, inordi-
nate appetite, symptoms of pain in the belly,like those of
gripes, unhealthy appearance of coat, a little exsiccated

PART n. 2 II

LKCTURE XLVII.

Oti the Liver.

The liver is the largest gland in the body, and per-
forms the secretion of bile.

Having already (in Lecture the forty-second) de-
scribed the situation and connexions of this viscus, it
will not be necessary to repeat them here.

The figure of the liver varies somewhat in different
animals : its divisions are better marked, and its
edges thinner, in quadrupeds than in the human sub-
ject.

Its color is that of a reddish brown ; this will vary,
however, somewhat in hue, according to the quantity
of blood the gland may contain.

In the human subject and in all quadrupeds, the
liver is partially divided by clefts or fissures in its svib-
stance into lobes, of which there is great variety, as to
number and shape, in the different genera of the latter :
in the horse it is composed of two principal divisions
or lobes, united in the middle by the portio media or
intervening portion, and of two lobuli or small lobes.
The right or large lobe is placed entirely in the right
hypochondrium. Along its concave part, from its
obtuse border, proceeds the lobulm caudatus ; a triangu-

On the Liver.

469

lar portion of liver included within the fold of the liga-
mentum latum dextrum. The other lobulus, having a
circular border with several clefts or fissures through it,
whence it may be denominated the lobulus scissatus,
springs from the anterior and under part of the portio
media. The left lobe, nearly equal in size to the right,
has the general outline of an oval ; indeed this figure
would be perfect were it not interrupted by the union
of the lobe with the portio media.

Eveiy part of the liver, with the exception of the
spaces occupied by the coronary ligament and posterior
vena cava, is so closely invested by peritoneum that the
membrane has the appearance of being a distinct
capsule ; but, though some have described a covering
underneath, as separable from it, which they have
named the tunica cellulosa hepatis, anatomists in
general do not admit of any such or proper tunic.

The liver, like other true glands, is composed of
arteries, veins, excretory ducts, nerves and absorbents,
united together by a particular tissue, to express which
we have the term, parenchyma. Its arteries, named
from the trunk from which they spring, the hepatic, a
branch of the abdominal aorta, are but of small size in
proportion to its bulk, and in comparison with others
which supply the viscera in the vicinity: e.g. if we
contrast the splenic arteries with the spleen, or the
emulgent with the kidney, and then compare them
with the hepatic, and contrast the hepatic with the
liver, we shall find that the latter are remarkably dis-
proportionately small.

In the venous system. of the liver, we discover a
peculiarity, of which no parallel instance is to be found
in the animal economy; not only is it furnished with

470

On the Ldver.

veins that perform the office of returning blood, but it
has others for the purpose of conveying blood to it,
which are to be regarded in the light of secerning
arteries. The trunk they spring from is called the
vena portarum, a vessel formed out of the union of the
splenic and mesenteric veins, which takes place imme-
diately above the pancreas. This vein crosses over the
duodenum, to the right of the hepatic artery and duct,
and proceeds to the concave part of the liver ; about
opposite to the middle of the right lobe, it bifui'cates ;
the right division directly enters the gland, the left
continues its course forward, in company with the he-
patic artery, and sub-dividea into two others, which
penetrate the portio media and left lobe of the organ.
Their branches spread out in an arborescent manner
within the substance of the liver, ramify to great
minut(3ness, and at length radiate into a system of
capillaiy tubes, which, from some peculiarities they ex-
hibit in their arrangement, have been named penicilli.

The hepatic veins, the vessels that return the blood
conveyed hither by the vena portarum and hepatic
artery, are in the horse small but exceeding numerous :
their orifices may be seen, appearing like so many pin-
holes, by slitting open the posterior vena cava.

The hepatic duct, remarkable for the whiteness of its
coats, will be found running along the upper and inner
edge of the right lobe, and receiving in its course many
stoall ductiform tubes from the interior of the gland ;
its trunk afterwards accompanies the hepatic arteiy, to
.the right of which, and below the vena portarum, it
continues its passage to the duodenum. This duct is a
muscular tube, having a membranous lining, large
enough to admit of the introduction of the little finger,

On the Liver.

471

and about three inches in length. It pierces the coats
of the duodenum, about six inches from the stomach, in
conjunction with the pancreatic duct, and opens by an
orifice distinct from the one of that duct ; though the
terminations of both are guarded by one circular flap,
composed of doublings of the inner and muscular coats
of the gut, which performs a valvular function in pre-
venting the entrance of alimentary matters into these
tubes.

The nei-ves of the liver, neither large nor numerous,
for it does not appear to possess much sensibility either
, in health or disease, come principally from the sympa-
thetic ; it receives also a few filaments from the par
vagum. Its lymphatic vessels, on the other hand, are
extremely plentiful and are readily demonstrated : we
have nothing more to do than to insert a small inject-
ing pipe under its peritoneal capsule, and allow quick-
silver to diffuse itself, and we shall instantly fill very
many of them, making a beautiful, vascular,' arborescent
display upon the surface.

The hepatic artery having entered the substance of
the organ, disperses its ramifications through every part,
which terminate not only in nutrient extremities, but
in vessels of communication with all the others ; at least,
if fine injection be thrown in, it will not only pass ittto
the hepatic veins, but also find its way into the branches
of the vena portarum, and those of the hepatic duct ;
in fact, the researches of anatomy appear to ptoVe, that
there is free intercommunicatioh between these dif-
ferent seta of vessels, for if either of the others be in-
jected (except the hepatic v6inS which have valves) th^
same result is afforded. If a piece be torn or broken

472

On. ihe Liver.

off the liver, we shall perceive upon the lacerated sur-
faces numerous little granulary eminences, to which
anatomists have given the name of aci?ii : these small
bodies, which are united together by a fine cellular
web, are^composed of the ramifications of some or all
of the vessels I have enumerated ; but what their inti-
mate structure is, or how or in what manner they are
constituted, remains yet to be explained. Again, if we
closely inspect the surface of a clean cut into its sub-
stance, we shall perceive numerous minute pores, from
which a yellowish fluid may be expressed : these are
the poi i biliarii — the .radicles of the hepatic duct, which
run in company with the arterial and venous ramifica-
tions, repeatedly unite and re-unite until, at length,
they all end in a single tube. Now, to sum up the
functions of these several parts, as far as the most
rational inferences and suppositions will warrant, it is
believed, that the separation of bile from the blood
takes place within the acini, that the penicilli are the
secerning vessels, and that the secreted fluid is re-
ceived by the pori biliarii, and by them conducted into
the hepatic duct. It has long been, and still is, an
undetermined point in physiology, whether the secre-
tion of bile is performed by the vena portarum alone, or
whether the hepatic artery assists in that operation.
It has been said, on one side, that bile could only be
produced from venous blood, and consequently that the
blood of the hepatic artery must be wholly consumed
in the nourishment of the organ ; two cases however
that have occurred in the human subject, where the
vena portarum was wanting, (the vein corresponding to
it , terminating in the vena cava inferior,) the hepatic

On the Liver.

473

artery unusually large, and the hepatic veins were ending
in the vena cava, have refuted this opinion*. An argu-
ment in favor of some bile, under ordinary circumstances,
being secreted from arterial blood, is the communication
which the hepatic artery can be proved to have with the
vena portarum and the hepatic duct ; when we look,
however, at the volume of this gland, and contrast it with
the size of the hepatic artery, or even compare the latter
with the hepatic duct, we shall be convinced that, if it
do secrete at all, it can be but to a very trifling amount,
after it has expended blood enough for the nourishment
of the organ. On the whole, we may probably regard
the hepatic artery in relation to the liver in the same
light as we do the bronchial to the lung, and consider
the system of the vena portarum as the proper biliary
apparatus.

The Gall Bladder, an appendage to the liver
1^ possessed by man and most other animals, is merely a
receptacle for bile, in which that fluid becomes concen-
trated by absorption of its watery parts, and, at such
times as it is required, passes in that state inta ano-
ther duct leading to the duodenum, which also has a
communication with the hepatic, to mix with the chy-
mous mass : this viscus, although one of much utility,
does not appear to be indispensably necessary to the
^ well-being of the animal, as no ill consequences have
resulted from its removal. The horse and some other
quadrupeds have no gall bladder, consequently the bile
flows along the duct, as fast as it is secreted, into the
duodenum : why these animals are not furnished with

W

* One is detailed by Mr. Abernethv in vol. Ixxxiii. of the Phi-
losophical Transactions ; the other by Mr. Lawkeuce in vol. iv.
of the Medico-Chirurgical Transactions.

474 On the Diseases of the Liver.

such an appendage, I shall endeavour to show in the
lectures (»n digestion.

The principal use of the liver probably is to secrete
bile ; I say the principal, for there would appear to be
some other, yet but imperfectly made out : an opinion
broached long ago by those writers who considered the
small quantity of bile produced as inadequate to employ
altogether a viscus of such magnitude, and one that
has received much support from later anatomical and
physiological researches. If the hepatic duct be tied,
or the gland be so diseased that the secretion cannot go
on, the animal, it is said, not only becomes constipated
in its bowels, but suffers much from disordered general
health : hence it has been conjectured, that something
noxious to the animal economy is therein eliminated
from the blood, and discharged with the bile into
the alimentary canal.

The very conclusive experiments of Mr. Brodie
leave us no room to doubt " that the office of the bile
is to change the nutritious part of the chyme into
chyle, and to separate from it the excrementitious
matter It has been imagined also by some, to sti-
mulate in its passage the internal surface of the intes-
tines, and thereby produce a more ready expulsion of
the excrement, which owes its yellow color to the pre-
sence of this fluid.

On the Diseases of' the Liver.

In horses, hepatitis (inflammation of the liver) is by
no means of frequent occurrence ; a fact much more
satisfactorily accounted for, in my opinion, by referring
it to an absence of those causes which generally induce

* Vide No. xxviii. of the Journal of Arts and Science.

On the Diseases of the Liver. 475

hepatic disease in the human subject, than by any in-
ferences we may draw from its singleness or simplicity
of duct ; though, in offering this explanation, I wish the
axiom to be kept in view, that the more compUcated
any organ is in its construction, the more liable it is to
be out of repair. Intemperance in eating and drinking,
passions of the mind, and sedentaiy habits, to which
the majority of these complaints may be referred in the
human subject, cannot be assigned as causes of disease
in horses ; adequate reasons, I think, to account for
the comparative rarity of such cases : continued expo-
sure to heat also produces them in us, so that in hot
climates or during hot seasons, hepatitis is very pre-
valent; whether climate or exposure has any such
effect in the horse, I am unprepared to offer an opinion.
It has been remarked by those who have extended their
pathological observations to cattle, that such as are
stall-fed, as oxen, &c. not unfrequently shew signs of
diseased liver ; and that, in such animals, after death,
there is an unusual yellowness of the fat : under these
circumstances, the exciting causes appear to be a highly
nutritive diet, combined with want of exercise, in the
horse, however, not only are these cases seldom seen,
but they are occasionally, when present, mistaken for
others of a different nature, or altogether disregarded
as unimportant objects of practice ; and T trust that
most veterinary practitioners will bear me out in this
remark, when I allege, as a reason, that, in truth,
diseases of this organ are far from being well marked.
Even in the human subject, a patient who can ex-
press the seat and kind of pain felt, and in whom we
may sometimes detect morbid action in the viscus by

476 On Lite Diseases of the Liver.

pressuiGj cases occur in which it is extremely difficult
to distinguish it from inflammation within the chest ;
how much oftener then must it be obscure in the horse,
who can furnish us with no such signs to direct us in
our diagnosis.

. Dissections prove to us, that this disease has not
always precisely the same seat : in some cases the in-
flammation is confined to the peritoneal tunic ; in others,
the substance of the organ only is affected. The first
will probably give rise to a set of symptoms so much re-
sembling pneumonia, that I doubt much whether any
one could positively say to which they belonged ; of the
last, however, we may and do have now and then, un-
equivocal evidence. What contributes still more to
confound these cases, is, that hepatitis is an occasional
concomitant of thoracic inflammation, so that the horse
will shew a yellowness about the eyes at a time that the
symptoms manifest pneumonic disease ; and to this cir-
cumstance probably we may ascribe the alleged fi'e-
quency of what is called yelloics, by many writers of
works on farriery. Without drawing any anahigical
deductions, from human to veterinary pathology, and
without even adverting to the sensibility of the organ in
a healthy condition, I may state, from my own observa-
tion, that the horse expresses but little pain who labors
under inflammation of the liver itself, and more especially
if that inflammation be of a chronic kind; he may be
inactive, moping, and dull, oft" his appetite, and appear
to suffer much inwardly, but he will exhibit none of
those signs of acute pain which accompany inflamma-
tory affections of the stomach or intestines : at the same
time, chronic affections of the other viscera may render

On the Diseases of the iJver. 477

liim alike spiritless and stupid, so that in fact we can
collect little or nothing certain from such symptoms *.
Our chief dependauce must be on the state of the
bowels, on the nature of the evacuations, and on the
appearance of bile in the system. Costiveness be
present, or the intestinal discharges may be sparing,
( buttoni/,) and not of their ordinary color, from being de-
ficient or altogether void of bihary fluid, though I be-
lieve this to be very uncommon ; on the other hand, it
may happen that purging is a symptom, from a redun-
dancy of bile. Again, jaundice may originate in hepar
titis, which the yellow tinge of the tunica conjunctiva
of the eye, and the skin about the mouth and nose,
together with the high color of the urine, will ma-
nifestly denote the presence of ; this however is
only likely to happen under certain circumstances,
as from compression of the ducts by tumefaction of
the substance of the organ, so that the passage
of bile through them is prevented, or in consequence
of the inflammation extending to the duct itself,
whereby its coats become thickened and its canal con-
tracted. Another symptom, that has been casually no-
ticed, is, that the horse is lame, a hint we have imported
from human practice ; but we must be cautious how we
give this symptom currency, for, though it is true that

* Of the truth of this remark we had about a twelvemonth ago
two unfortimate instances. One was a horse of high vakie that
exhibited all the general symptoms of extreme ill health, without
directing our attention by any thing we could detect, to any parti-
cular part: he evidently grew worse every day, and though we
were inclined to refer his disease to the liver, we were by no means
confident in our opinion. In the course of ten days, death took
place, and dissection shewed the most destructive ravages of dis-
ease in this viscus.

478 On the Diseases of the Live?'.

men, having hepatitis, now and then complain of pain
about the top of the shoulder, the opinion of physicians
in general is, that it is a symptom that is frequently want-
ing, and that its absence is by no means a proof that dis-
ease is not going on in the liver. I have never met with a
single instance of it myself, and have only one authenti-
cated case to adduce here, which is one that is usually
related by Professor Coleman in his lectures. The horse
belonged to the Royal Artillery, at Woolwich, and was
lame in the off fore leg, by which eventually he became
so disabled that he could scarcely project the limb in
attempting to walk : no local cause being apparent,
and the lameness in spite of remedy continuing, the
animal was at length destroyed. On dissection of the
limb, every part of it was found free from disease ; but,
on examination of the viscera, a thorn of great length
was discovered sticking in the substance of the liver.
These then are what may be considered as the diagnos-
tic symptoms of hepatitis ; I have endeavoured to shew
how much reliance is to be placed in any one of them,
and in all of them collectively : of course, they will
generally be attended with the common febrile disturb-
ance— though I have never witnessed much derange-
ment in the respiration, and, as I said before, accom-
panied with dejection and more or less stupor, and by
the intensity of these symptoms and a due consideration
of all the circumstances of the case, we must, if called
on, frame our prognosis.

It is difficult to say what the causes of hepatitis are in
the hoise. External injury, such as a kick or a blow on
the right side, might give rise to it; or, as we have seen
above, a wound o( the organ : perhaps it sometimes
originates in fulness of condition and in the irregularity

On I he Diseases of the Liver. 479

with which many horses are worked or exercised, or in
the total want of exercise.

This disease, like other acute inflammations, may
terminate in resolution. Should its peritoneal covering
only be aft'ected, an opacity and thickening of it, or
some adhesion of it to the contiguous parts, will probably
ensue : I have in two or three cases found it firmly glued,
in this manner, to the diaphragm *. A common termi-
nation of it in the human subject is in suppuration, or
abscess ; and this happens when inflammation has at-
tacked the substance of the gland, and has been pro-
tracted : my father has a recollection of two or three such
cases; but, unfortunately, no minutes were made of
them. I am disposed to think that this disease oftener
assumes the chronic than the acute form; for I have
heard of and seen many instances in which the liver
exhibited morbid appearances after death, though the
horse appeared to have enjoyed perfect health during life.
The most common alteration of its natural structure
seen in these cases, is what is called schirrus ; a disease
that is supposed to originate in the effusion of adhesive
matter into the parenchymatous substance, whereby that
is rendered more compact, is solidified and indurated.
Tubercles also are now and then met with : those that I
have dissected have been of a greyish color, and yellowish
white.

The disease being made out, the treatment is readily
determined on. Bleeding, purging, and counter-irrita-
tion comprehend the efficacious means ; all others I

* Some few years back, a horse, whose malady was not made
out by the practitioner in attendance, died purely from this dis-
ease: at least, inflammation of the liver, and adhesion of it to the
diaphragm, were the only morbid appearances I could find after
death.

480

Jaundki:.

know of, [ regard as empirical or valueless. Sliould it
be an acute case, take away from four to six quarts of
blood ; but if it has the chronic type, I generally draw
two or three, and repeat the operation every second,
third, or fourth day. Purgatives are peculiarly adapted
to these cases, either acute or chronic, in consequence of
their giving rise to the consumption of much of that blood
which must otherwise be returned to the vena portarum
and distend the vessels of the liver ; and, for this reason, it
is important that we do not mistake it for pneumonia,
and vice versa. Give a dose of aloes alone* — no other
purgative will answer the purpose so well, and repeat it
in the course of forty-eight hours, should its operation
have ceased, or in half that interval, should it have not
operated at all; and do this until some impression shall
have been made on the disease. Mercurial purges are in-
jurious— they are direct stimulants to a gland already dis-
turbed and irritated by inflammatory action. Blisters
should be applied as soon as the animal has been purged :
rub from three to four ounces of the infus. lyttee over the
region of the liver, and repeat the application as often
as is necessary to keep up a serous issue. In chronic
cases, blisters are also very useful ; or setons may be in-
troduced in the side.

Jaundice.

Rather an unfrequent disease among horses is
jaundice. And one reason appears self-evident as soon
as we are put in possession of a knowledge of the
causes from which it may proceed. 1 mentioned swell-
ing or compression of the hepatic duct as one, in speak-

* R Aloes Vulg. Ext. 3x.

Syrup. Zingib. q. s. ut ft. Bol. Statmi dandus.

Jaundice. 481

ing of it as a symptom of hepatitis, and probably this is
the most common one. In the human subject, it fre-
quently arises from obstruction of the ducts, either from
collected or concreted bile in them, to which the name of
biliary calculi is given; or it may be the effect of spasm
in the ducts, or in that part of the duodenum where
they terminate : but I am not aware that cases of this kind
have occurred in veterinary practice. And one reason,
I repeat, is obvious. The horse has but a single duct,
through which the bile flows as fast as it is secreted ; it
has no retrogade course to take, no receptacle to collect
in and to concrete into gall-stones : and, as a proof
that this is one reason, dogs and such other of our do-
mestic quadrupeds as have gall bladders, are all of
them much oftener jaundiced than horses. People who
lead sedentary lives, such as corpulent subjects and wo-
men, are predisposed to jaundice; in them, the bile
often grows inspissated in its ducts, and biliary calculi
are now and then detected in the stools : this is a cause
of disorder, as I have said before, that we can but rarely
adduce in veterinary practice.

Jaundice, produced from whatever cause it may be, con-
sists in the absorption of unchanged bile into the circula-
tion, which bile becomes diffused and conveyed to every
part, giving rise to those appearances that are so remark-
ably characteristic of its presence. It does not appear
to originate either in defective or altered secretion ; for,
had the liver not performed its office, how could we ex-
plain the appearance of bile in the system at all ?

Tlie yellow aspect that jaundice gives to the skin, the
mouth, and the eyes, at once betrays its presence.
The skin is everywhere dyed yellow, though the change
13 only visible to us in places bare of hair. The menir-
PA RT n. 2 I

482

Jaundice.

brane of the mouth puts on the same appearance. The
conjunctiva (the membrane lining the eye-Hds) has a
yellowish pink hue, the cornea is obscured, a yellow
sediment may often be perceived floating in the anterior
chamber, and the iris itself is tinged in places with this
yellow dye. The bowels are costive : the excrement
that is voided is hard, butlofiy, and dark-colored, be-
smeared often with a yellow slimy matter, like bile diffused
in mucus, and consists of dryish masses of ill-digested
aliment. The urine is a deep yellow or orange color,
and is sparing in quantity. In the human subject, the
absorption of bile into the system often generates con-
siderable disorder, operates in fact like so much poison-
ous matter, exciting an itching sensation of the skin,
and depressing the strength and spirits of the patient j
and the latter of these effects is often very remarkable in
jaundiced horses. The eyelids are drooping or closed,
the head hangs down, there is evident sinking both of
strength and spirits, and often there is a degree of moping
stupor present, which at times borders on vertigo, so
that the animal walks unsteadily or reels as he moves ;
his pulse is about 60° or 65° ; his respiration is unaffected,
and his flank untucked up.

In the treatment of jaundice our sheet-anchor is purg-
ing. No time should be lost in exhibiting ten or twelve
drams of aloes ; and, if we can insure the administration
of it, the decoction is preferable to a bolus. If there
was much stupor or vertigo present, I would bleed, but
not largely. I would follow up the first dose of aloes
with half-an-ounce in solution every twelve hours until
purgation came on: we need be under no apprehensions
of super-purgatiou in these cases. As soon as the
bowels are freely opened, apply a blister to the right

Jaundice.

483

side, and repeat it every twelve hours. It may be ne-
cessary to recur to the venesection.

Now and then jaundice terminates fatally, and when
it does so, the event is commonly sudden : probably
some time has elapsed before we are called in, the
bowels resist our first dose of medicine, in the mean
time the pulse rises in spite of our recurrence to the use
of the lancet, the skin and extreme parts become cold,
the animal grows senseless and perhaps vertiginous, and
in that state suddenly drops and expires. On dissection,
the liver is found glutted with bile. I found the gland
so prodigiously distended in one case that the right lobe
of it had burst, and displayed a considerable fissure.

Now and then we hear of cases of rupture of the
liver. I have never been present, but at the one mentioned
above, myself ; but I am told tliat large, heavy, draft
horses are more particularly liable to the accident ; and
that it happens in the violent efforts they are compelled
to make in drawing heavy loads.

2 I 2

LECTURE XLVIII.

On the Spleen.

The spleen is an organ of an extended pyramidal
figure, lying between the stomach and false ribs, in the
left hypochondrium.

This viscus owes its color principally to the blood
with which it is glutted after death. Prior to expo-
sure to the air, which reddens it, it is of a blue mottled
or marble hue ; it is much darker however, and resem-
bles the color of venous blood when cut into.

Though its size varies somewhat in different horses,
in a healthy condition, it seldom or never exceeds three
pounds in weight.

The spleen is adapted in shape to the space it occu-
pies, being concave next the stomach, and convex
where it is opposed to the ribs ; it differs altogether
remarkably in figure from that of the human subject;
for it is broad and thick at one end, and lengthened out
nearly to a point at the other.

It receives a complete covering from the peritoneum,
to which it owes its apparent solidity and firmness of
substance ; for, when stripped of this tunic, its texture
is found to be soft, lacerable, and spongy, and to present

On the Spleen. 485

internally all the appearances of a gland; and. as
such any one would not fail to regard it who had not
made himself acquainted with its intimate structure.
It differs remarkably however from a gland, in not hav-
ing any excretory duct : an appendage for which it
has no occasion, as it is not believed to perform any
secretory function. It is now generally supposed, that
the arteries of the spleen, after having branched out
within its substance into innumerable ramifications,
terminate in cells, of a membranous composition^
from which veins, about equal in number, take their
origin. To elucidate this structure, it has been likened
to a piece of sponge, or a honey-comb ; to which, if
blood-vessels were superadded, probably the general
composition of it bears some resemblance. By regard-
ing it as a spongy or porous body, we can account
very satisfactorily for the extreme variableness in the
volume and weight of this organ ; for it is obvious that
it will admit of great latitude in its state of distention,
and that its weight and volume must greatly depend
upon the quantity of blood it may contain. It also pos-
sesses nerves, though they are but small, as well as
absorbents, which vessels are very numerous, and rea-
dily demonstrable by injecting quicksilver under its,
peritoneal tunic.

This viscus receives its blood from the splenic artery,
a large branch of the posterior aorta, which, in running
along the great curvature of the stomach, detaches nu-
merous short ramifications both to it and to the spleen.
The splenic veins, much larger than the arteries, unite
with those of the stomach, and form a vessel that
largely contributes to the production of the vena por-
tanini. Its nerves corac from the coeliac pexus.

486 On the Spleen.

The magnitude and organization of the spleen in the
higher order of animals, together with the constancy
of its presence, are of themselves forcible arguments
to establish its importance in the animal constitution ;
it would appear however, from some facts, not to be
equally useful with other abdominal viscera ; for, if it
be carefully extirpated, the animal will not only sur-
vive, but thrive and do well : indeed, in the human
subject, it has been found after death so disorganized
from disease as to have been apparently incapable of
performing its function during life ; and one case is
related in which it was cut out without the individual
experiencing any great inconvenience from its loss.

From the general resemblance in composition be-
tween this organ and those that are known to be
glandular, very diligent search has been made after an
excretory duct; no vessel of the kind, however, has
over been demonstrated, though more than once have
anatomists been led away with the idea that they had
discovered traces of one. Seeing, then, that the
spleen was without a duct, (and, as I observed before,
there is no want of one, there being no secretion carried
on,) physiologists, compelled to relinquish the notion
of its being a gland, have attempted to explain its use
from what appears to be a faithful description of its
structure, connections, and relative situation.

It would be an idle and a fruitless task for me to
collect and expound here the many theories that have
engaged attention from time to time on the physiology
of tliis organ : rather let me cursorily examine those
which are at the present day considered, if not as more
conclusive, at least more feasible than any that have
preceded them.

On the Spleen. 487

Some are of opinion that the function of the spleen
is connected with the economy of the liver. That, by
retarding the circulation and otherwise altering the nature
of the blood, it renders that fluid peculiarly i\t for the se-
cretion of the bile. Although splenic blood, however,
appears to have had its properties somewhat altered from
that M'hich is found in other viscera, inasmuch as it
is seldom or never seen coagulated, and, as has been
proved by Sir Evebard Home, as it contains a greater
proportion of serum, still we have no decisive evidence
that these changes are wrought in it by the spleen, nor
have we any just reasons to believe that they are essen-
tial to the secretion of bile ; for, as I mentioned in a
former lecture, cases have occurred in the human sub-
ject in which the vena portarum terminated in the vena
cava, and in which the bile consequently must have
been produced from arterial blood alone.

In the face of these objections, others, without any
allusion to the specific properties of splenic blood, have
attributed to the spleen simply the office of altering its
character from arterial to venous, by conducting it
through small and tortuous canals, and detaining the
fluid for a certain time within its cells. The advantages
of this, say they, are evident. The supply of venous
blood from the other chylo-poietic viscera being insuffi-
cient for the purposes of the liver, the splenic blood
makes up the complement ; had such a provision not
been made, a vessel, probably equal in size to the vena
portarum itself, must have been superadded to the arte-
rial system, and this would have demanded a consider-
able augmentation in the aggregate quantity of blood.
The blood returned by the veins of the spleen is cer-
tainly much darker than that which flows in its arteries ;

488 On the Spleen.

and its structure (so far as we are acquainted with it)
will tend to produce this change by retarding the circu-
lation; but, independently of the fact that bile can be
obtained from arterial blood, it appears to me to be
incongruous with other beautiful and harmonious opera-
tions, to suppose that an organ should be constructed
of magnitude and complication like the spleen, purely
for the purpose of undoing what has but now required
the elaboration of the lungs to elfect.

Another, and probably the most ingenious of the
modern theories, is that of Dr. Haighton's. This
gentleman thought, that the spleen acted as a diverticu-
lum to the blood, and thus proved subordinate in func-
tion to the stomach. That, when the stomach is dis-
tended, the spleen being compressed between it and
the ribs, the splenic artery cannot receive so much
blood, and consequently it must flow in abundance into
the gastric arteries, which require more at this time for
the supply of gastric secretion ; on the other hand,
when the stomach is empty, the spleen again expands,
and admits of a considerable influx of blood. It has
been at-gued against this theory, that pressure and coun-
tcrpressure being equal, if the stomach obstructs the
passage of blood into the spleen, the contrary to this
must happen. And so it would if these bodies were
placed under similar circumstances ; but, as the splenic
arteries all run between the stomach and the spleen, and
many of the gastric are entirely removed from such com-
pression, and as the one organ is so much smaller than
the other, it is evident that the pressure and counter-
pressure, though equal in force, are very unequal in
regard to their eflfects. But, although this argument is not
valid, there are some facts that tend not a little to shake

On the Diseases of the Spleen. 489

tliis opinion, and of these probabl)' llie strongest arise
from a survey of these organs in the h-orse : it appears to
be however the least objectionable theory we have, and
is for certain one that has not been adopted without the
concurrence of many nice and difficult experiments.

On the Diseases of the Spleen.

This is an organ but little subject lo disease in
horses ; and when it is diseased, I know of no symptoms
especially arising therefrom.

In two, or three instances, I have found it very much
enlarged, though not, to appearance, in the least al-
tered in texture : in one of them, it weighed fourteen
pounds, two ounces — eleven pounds more than its ordi-
nary weight. This is by no means a very rare occur-
rence in the human subject ; and more particularly in
people that have experienced repeated attacks of inter-
mittent fever; in whom the enlarged spleen is called
the ague cake : how, or why this takes place, however,
is not at all known. Should we, from any circumstance
whatever, be induced to believe that this organ was in a
state of disease, we are to treat the case by the same
rules and remedies as we would one of diseased liver.

In the year 1812, I was called to rather a singular
case — a rupture of the spleen. A horse that was at
strawyard, was seen about seven p. m. manifesting
symptoms of gripes; he was accordingly taken into the
stable, and made to swallow in a drench two ounces of
oil of turpentine. As he appeared to be relieved,
nothing further was done that evening. The next morn-
ing, he had a relapse of the same symptoms in a more
violent degree, of which he died about ten a. m.
Shortly afterwards he was opened ; and the first appear-

490

On the Pancreas.

ance that attracted notice was, that the guts were
stained here and there with blood ; and they were no
sooner removed than from ten to twelve quarts of that
fluid, partly congealed, were found effused into the
belly. At first, I suspected this hemorrhage to have
been caused by the bursting of some important blood-
vessel ; but further examination shewed the spleen to
have been ruptured to the extent of about four inches,
along its convex border, where it is opposed to the false
ribs. While I was inspecting this wound in the spleen,
which was now filled with a coagulum, I was amazed at
the prodigious distention of the stomach with air — in-
deed, it occupied so much of the surrounding space
that I felt inclined to believe that it might, by com-
pression, have been the cause of the rent in this viscus,
which probably happened during some violent effort in
respiration ; for I could find no mark whatever of any
external injury upon the side, either inwardly or outwardly.

Mr. Hendeeson has a specimen of ossification of
the spleen. An abscess, about the size of an apple,
whose parietes are bony, had formed in it next the
stomach, about midway between its base and apex,
from which was liberated, after death, a coffee-colored
purulent fluid. It was taken from a horse much wasted
in condition, that was killed at the slaughter-house.

On the Pancreas.
The pancreas, in common language the sweetbread,
is a glandular organ, situated across the spine in the
epigastric region, that prepares a fluid supposed to be of
use in perfecting the digestive process *.

* For the connections and relative situation of tliis viscus, vide
Lect. xlii.

On the Pancreas.

491

It has no peritoneal covering — the membrane simply
passes over it.

The pancreas has been divided into head, body, and
tail; it has also a fourth part, attaclied to the right side
of the spine, a prolongation from its head, to which
the name of pancreas minor has been given.

Anatomists all agree, that there exists a similarity of
structure between this organ and the salivary glands ; and
what tends to confirm this opinion, is, the resemblance that
the pancreatic fluid bears to common saliva. The pan-
creas is of a pale red or speckled color, and is composed
of many small lobes or lobules, which, though they in-
timately adhere together by a fine cellular tissue, are
perfectly distinct from one another in regard to their
ultimate organization. For every one of these lobules,
or (as some call them) acini, appears to be constituted
of a set of arteries, veins, and ducts, which vessels have
no communication, except through the medium of their
trunks, with those of any other ; so that a certain quantity
of secretion is prepared within, and discharged from, every
one of them : in fact, every lobule may be said to be a dis-
tinct gland of itself, and this is the case in respect to the sa-
livary glands. In the dissection of an injected pancreas, we
may trace many arterial twigs into these acini, which are
detached at right angles from the principal pancreatic ar-
tery as it pervades the interior of the gland ; the veins also
may be seen accompanying the arteries. The duct, which
consists of two main branches, has a similar mode of
ramification. Having been formed at the extreme end
of the gland by the union of several smaller tubes, it
takes its course through the middle of the viscus, re-
ceiving in its way other little ductiform vessels which

492

On the Pancreas.

come from the neighbouring lobules and contribute to
augment its size. Thus formed, the long branch
issues from the body of the gland, the short and larger
one from the head, and pancreas minor ; the two then
unite into one trunk, about an inch in length, which
runs directly from the spleen to the duodenum, and
pierces the latter alongside of the hepatic duct. It is
composed of a thin, pellucid membrane of considerable
strength, and is large enough in its calibre to admit of
the introduction of the finger.

The pancreatic arteries are derived mostly from the
hepatic ; many however come from the splenic, in its
course to the left side of the abdomen, and one or two
from the gastric. The veins are tributary to the vena
porlarum. The small nerves discovered in it, are fur-
nished by the coeliac plexus.

Nothing precise appears to be known about the use
of the pancreatic juice; though, in its nature, it is
generally allowed to resemble saliva. The duct has
been tied, and the gland removed altogether, in dogs,
without any apparent disturbance of the animal's health.
The quantity secreted is believed to be considerable ; at
least, so it would appear from many experiments that
have been made to collect it ; but, like the separation of
bile, it is probably greatest during digestion : indeed, if
we might be permitted to reason from its resemblance in
structure and secretion to the salivary glands, we should
say that it was only at such times that the pancreatic
juice flowed at all. We may attribute to this fluid,
perhaps, the attenuation of the chymous mass; and,
from ita entering the duodenum at the same lime (and
sometimes through the same orifice) as the bile, it may

On the Pancreas.

493

also dilute that secretion, and serve to diffuse it more
uniformly through, or incorporate it with, the alimentary
mass.

In the course of the post mortem examinations at
this establishment, which have neither been few nor un-
productive, no morbid appearance of the pancreas has
been recorded or noticed. In the ox, 1 have heard of
calculi having been found in it.

LECTURE XLIX.

On Digestion.

In my lecture on the stomach, I observed, that ani-
mals alone were provided with digestive organs ; and
that this was so universally the case that even the
lowest orders presented something of the kind in their
constitution ; and that this important fact had prompted
physiologists to designate the stomach as the chief
characteristic between animal and vegetable existence.
It is by means of a digestive apparatus that the food
undergoes those changes which, in the end, assimilate
it to the nature of the component parts of that animal
whose nourishment and growth it is destined to sup-
port. In order to take a comprehensive view of the
process of digestion, I shall commence with the masti-
cation of the food, and its transmission through the
pharynx and esophagus into the stomach ; secondly, I
shall examine what changes it undergoes in that organ ;
and thirdly, I shall inquire in what way the alimentary
mass, after it has entered the intestinal canal, is con-
verted into nutritive and cxcrementitious parts, and
how these parts are separated from each other.

By the natural historian, the horse must be regarded.

On Digestion. 495

in every point of view, as a graminivorous animal;
his natural habits of living are such that he loathes,
even to abhorrence, any kind of animal food ; it will
therefore be unnecessary for me to dilate on this part
of my subject. But we have other (we may call them
anatomical) proofs of his being so ; for, by the rules
laid down for the classification of animals according
to the food upon which they are known to live, we can
satisfactorily demonstrate that the horse differs essen-
tially in his internal conformation from those animals that
feed upon flesh, denommated carnivorous. In the lat-
ter, which are characterized by a savage and voracious
disposition, as animals of prey, the teeth are found to
be sharp and pointed, calculated for tearing the flesh
or breaking the bones of other animals ; the stomach
has no blind pouch, nor cuticular coat, but readily
admits of the passage of the aliment into the intes-
tines ; and the intestinal canal is short, and, generally
speaking, presents but few or no obstacles in its con-
struction to the progress of the alimentary mass — ^which
not only contains more nutriment in less bulk, but is
more easily digested and assimilated. But in gramini-
vorous animals, the teeth are formed either to cut or
bruise substances of a vegetable nature, and, from the
disposition of the molares and action of the jaws, to
grind them in a somewhat similar manner to the opera-
tion of a mill ; the stomach or intestines, or both, are
capacious, and so constructed as to retard the passage
of the ahmentary mass — in consequence of its requiring
longer time than animal food to undergo the necessary
changes. Man, who resembles in some of these pecu-
liarities both the carnivorous and gaminivorous animal,
has by some naturalists been ranked with the former ;

49B Mastication and Deglutition.

while others have maintained that the fruits of the earth,
and not the flesh of animals, was his natural food :
it appears, however, that enough may be advanced on
both sides to prove that he can either be carnivorous or
graminivorous, according to the circumstances under
which he is placed ; or rather, that he is both, and
may be specified as omnivoi'ous.

Mastication and Deglutition.

By mastication, or manducation, vulgarly called
chewing, is meant that operation of the jaws and teeth
by which the food is divided or bruised, and reduced to
such a state as to be easily swallowed. Man and some
animals are pi'ovided with hands or paws for the purpose
of taking food ; the horse and hosts of others are only
enabled to do so by means of a remarkable prolongation
of the jaws, and the combined operations of the lips
and teeth. The lips of a quadruped grazing, are sepa-
rated, and often everted, so as to embrace the herb,
which passing between the jaws, at the time partly
opened, is seized by the incisores, and, by a sudden
acclination of the head, nipped off and committed to
the tongue ; but, in taking food which is already sepa-
rated or divided, the nippers have little else to do than
to assist the lips in gathering it into the mouth in suit-
able quantities. By the actions of the tongue, and co-
adjuvancy of the muscular sides of the mouth, the
abscised portions of aliment are speedily carried up-
ward and distributed over the lateral parts of the cavity,
to be subjected to the operation of the grinding teeth.
By these teeth the food, according to its nature, is
bruised, broken down, or comminuted, and at the same
time mingled with saliva, which is now discharged upon

Mastication and Deglutition. 497

it in abundance from the ducts of the various salivary
glands. These operations are necessary to prepare the
food for the imbibition and action of the juices of the
stomach, and especially the preparative of mastication ;
for, as we shall hereafter discover, there are certain
sorts of provender which, unless they are broken or
crushed in the mouth, are not triturable or digestible by
any operation in the alimentary canal. Those portions
of aliment that have undergone sufficient mastication,
and softening by commixture with saliva, to render
their passage into the stomach unirritating and facile'
are collected together into a mass or bolus of moderate
size upon the dorsum of the tongue, which is made hol-
low to receive them ; whence, by the action of that organ,
aided by the co-operation of the muscles of the cheeks
and fauces, the bolus is propelled upward and back-
ward into the pharynx : the jaws being shut and fixed
at the moment, the tongue pressed against the palate,
the sides of the mouth compressed to prevent its re-
turn, and the velum paiati, which the bolus itself has
forced upward, obstructing its passage into the nose.
The pharynx having received the bolus, by the actions
of the constrictores transmits it into the esophagus, by
the successive contractions of the transverse muscular
fasciculi of which it is pressed onward and lodged in
the stomach.

Though this is the mode in which deglutition is
executed, these several performances, when the food is
masticated, so quickly succeed one another that the act
itself may be said to be but momentary ; indeed, so
rapid is the succession of ^ them that to the common
observer these operations appear to be simultaneous.
To shew that the aliment does pass into the stomach by

PART II. 2 K

498 Physiologif of the Stomach.

muscular agency, and that gravitation has nothing to
do with the act, we have only to remark that a horse
swallows as well with his head dependant as he does
with it erect ; indeed, the act of drinking, which is a
very curious one, is itself a demonstrative proof of it.
The way in which drinking is conducted, is this : — The
lips being immersed in water, and separated for its ad-
mission, the tongue is rendered concave upon its anterior
surface, and projected in close contact with them, along
whose hollowed dorsum, as along a channel, the fluid
mounts as it is imbibed by suction : the want of such
previous collocation of these paits, occasions the con-
fusion in swallowing when we drench a horse. The
animal exerts the power of suction, by first rendering his
mouth inaccessible to the external air, and then forming
a vacuum in it by inspiration, into which the water
rushes from the pressure of the atmosphere upon its
surface, as into the cylinder of a syringe : flowing
along the tongue into the pharynx, it ascends (should
the horse be drinking from a pond) in consequence of
the contractions of these parts, in successive portions,
by the groom called go-downs, through the esophagus
into the stomach.

I shall now take into consideration the

Physiology of the Stomach.
A STJBJECT of vast importance to the practitioner of
human medicine, and one of no inconsiderable moment
to him whose professional avocations are of a veterinary
nature. It is an axiom iu pathology, that unless we ai-e
acquainted with the natural habits of an animal, we
are incapable of arriving at a knowledge of its diseases,
ergo incompetent to treat them; and this principle

FJtysiologif of the Stomucli . 499

applies with equal force to every individual organ of
which the animal is composed — for unless we can re-
cognise healthy structure and economy, how are we to
detect morbid appearances and actions, and to prescribe
remedies to palliate or remove them ? In order that we
may have clear and correct notions of the physiology of
this organ,iet us first consider the functions of its seve-
ral parts separately ; then, the process of digestion as far
as regards the stomach itself ; and lastly, the natural
habits of this animal, in respect to his mode of living :
knowledge that will qualify us to form an opinion how
far his domestic treatment, or " stable management,"
is calculated to presei've this important organ in a state
of health.

First of all let us inquire why Nature, who has given
four stomachs to the ox and sheep, should have re-
stricted so large an animal as the horse to one, and
should have made that one much smaller, in compari-
son to the bulk of his body, than those of man and
quadrupeds in general : a fact of which I have already
given some demonstration by actual comparative ad-
measurement. And what makes this investigation the
more curious and interesting, is, that although the
stomach of the horse will contain so little, his consump-
tion of food is not only greater than that of carnivorous
and many other animals, but the aliment on which he
lives is of that kind which necessarily occupies very con-
siderable space, either in or out of the body. A man
probably will consume about a pound-and-a-half of solid
food at a meal ; a horse, we will say, about six pounds, <
all, or a great proportion, of which may be hay ; and
this, in respect to bulk, will occupy twelve or even
twenty times the space that a pound-and-a-half of any

2 K 2

500 Physiology of the Stomach.

sort of cooked meat or vegetables will ; and yet the
stomach of the latter will not contain three times as
much as that of the former! One natural and self-
evident conclusion from the foregoing facts, is, that the
food which a horse: eats cannot remain long in his sto-
mach— that portions of it must successively pass into
the intestinal canal, at short intervals, during the time
of feeding, in order to make room for those last swal-
lowed. We may also fairly draw this inference : — that
the stomach cannot, either in the empty or distended
state, occupy so much space in the abdomen of the
horse as it does, cateris paribus, in those of other qua-
drupeds ; consequently all parts in its immediate vici-
nity will be less compressed, when it is full of food,
than they otherwise would necessarily have been, had
it been larger. Of the contiguous parts, only the in-
testines and the diaphragm possess the power of
moving. Now, as the former lie principally in the
centre of the belly, and as their vermicular motions do
not tend towards the chest, it would appear that a large
or distended stomach could not much interfere with
them ; but, to the muscular partition between this
cavity and the thorax (the action of which has already
been explained) a crowded abdomen would prove a
heavy incumbrance — would oppose its recession and
embarrass the breath according to the bulk, advance,
and counter-pressure of the viscera in contact with it.
To prove that distention of the stomach does in ani-
mals interfere with the respiration, and embarrass it in
that same degree in which it is exerted, we have only
to select one or two out of the many instances familiar
to us all. Why is it that a man is short-winded after a
full meal ? or that he cannot perform exertion as be-

Physiology/ of the Stomach. 501

fore, without experiencing an uneasy sensation about
the chest? Why is it that a dog, that has satiated
himself with food, will not and cannot pursue his prey
with his usual alacrity and speed ? Finally, why is it,
but from a knowledge of these facts, that we keep our
racers and hunters short of. food and water, prior to
their being put to their arduous course ?

A priori, we shall be led to expect, that the horse of all
such animals must feel the least oppressed — suffer the
least inconvenience from being made to exert himself on
a full stomach ; and that he is so endowed, and super-emi-
nently so, as an animal engaged in the chase, every sports-
man can testify ; indeed, it has been said, and with much
truth, by Professor Coleman, " that he is the only qua-
druped that can be compelled to take violent exertion after
a full meal." It is not a very uncommon practice, though
by no means a prudent one, among those whose hunters
are their hacks on such occasions, to give a horse that has
come nine or ten miles to cover, a good feed of corn
prior to the hounds being thrown off, which he has no
sooner eaten than he is again bridled and afterwards
galloped perhaps for half-an-hour, an hour, or even two,
with little or no intermission : I mention this case to show
what a horse can be goaded to do, and what lie is able to
perform, on a full stomach. But, would the same per-
son, if he were going out shooting, give his dog a belly-
ful.'' Or would he feed his ox just prior to yoking him
to the plough Perhaps, with regard to the dog, it may
be answered that the comparison is not a fair one, inas-
much as it is altogether optional with him whether he
hunt or no; but if we observe the horse in a state of na-
ture, we shall find his habits of life to be such as not
only to confirm this specific energy, but to evince that

602 Physiology of the Stomach.

he has not the same disinclination to take violent exercise
under such circumstances that other quadrupeds have.
Only watch horses at grass — how seldom do you see one
lying down, or apparently disposed to rest himself, or even
remain quiet; on the contrary, most of them are busy
grazing, while others, vigilant and playful, are ever
ready to frisk and gallop about at every frivolous cause of
alarm. Indeed, in this part of his natural history, the
horse appears to differ from almost all other animals.
When a man or a dog has filled his stomach, no longer
urged by the sensation called hunger, he refuses to eat
more, and probably betakes himself to repose ; but a
horse, though he may have consumed twice or thrice as
much as his stomach can contain, feeds on without
showing any signs of satiety or inactivity. But this is not
the case with ruminants ; they having distended their
paunch lie down and commence rumination. It would
seem then, that the stomach of the horse, in comparison
to that of other animals, is made disproportionably small
in order to render him more effective as an animal of
speed and burthen, and in course more useful for the
various and manifold purposes for which he is employed
by man.

What are the respective uses of the coats of the
stomach ? With regard to the peritoneal, it strengthens
the viscus and is supposed to diminish tendency to rup-
ture in cases of over-distention ; it will also prevent
friction, by continually exhaling a serous vapor from its
surface.

Of the muscular coat, I have already mentioned one
use, viz. that of accommodating the organ, in point of
volume, to the bulk of the contained mass ; so that it may
be said, under certain limitations, to be always full:

Physiology of the Stomach. 503

when once however it has received such a quantity of
food as to distend it to a certain degree, the muscular
coat contracts, and by a regular and uniform compres-
sion, squeezes that portion of aliment lying next the
pyloric orifice into the first intestine, at which time
the valve of the pylorus arrests the passage of any gross
and imperfectly digested matters. Another use of this
coat, is to give to the organ a motion, somewhat similar
to that of the intestines, (the peristaltic,) which contri-
butes to the perfect digestion of the alimentary matters
by more equally and thoroughly mixing them with the
gastric secretions.

On the use of the third or cuticular coat, it will be
necessary for me to be more diffuse ; for opinions have
been propagated with regard to the physiology of this
part, which appear to me to be unsupported either by
direct observation and experiment, or even by sound
analogical deductions. It is said, that this insensible
lining serves the purpose of triture — that it comminutes,
crushes, or grinds the food by friction — by a similar mode
of operation as, though in a less degree than, the gizzards
of birds. Now in order to learn how this is, let us
briefly examine the process in these animals. In birds
or fowls, the grain first passes into a membranous
bag, called the craw or crop, where it undergoes some
preparatory mollification, before it is subjected to the
action of the gizzards — organs almost entirely composed
of red, fleshy fibres, whose substance and color denote
the concentration of intense muscular power. Here
it is, then, that the grain taken in whole (for the animal
has no teeth) is bruised — is ground, in fact, as efl'ectually
as if it had been in a mill ; and to demonstrate how ade-
quately and admirably these organs are constructed for

604 Physiology of the Stomach.

the purpose, Spallanzani says, speaking of the tri-
mrative power of the gizzard, " that glass is reduced to
dust by it, pieces of metal broken, and the points of
needles or lancets broken off with impunity *." Seeing
that all triturative power must reside in the muscular,
and that none can be possessed by the cuticular coat, I
was first led to doubt that the gizzard of the fowl and
stomach of the horse at all resembled each other in
function, from a bare examination and comparison of the
organs themselves : the one 1 found to be intensely red,
coarsely fibrous, thick, tough, and stronger, in propor-
tion to its size, even than the heart itself ; the other,
though no one disputes its muscularity, has not that
appearance but under close and accurate inspection, for
its fibres are weak, are pale, white in fact, and in some
places by no means very distinct to the naked eye; alto-
gether the stomach seems to possess little more muscu-
larity than the bladder, and is certainly inferior in that
respect to the rectum. There is another circumstance,
relative to the muscular fibres of the stomach, to which
I would draw attention ; which is, that those encircling
the cuticular, are neither stronger nor more numerous
than those surrounding the vascular lining ; on the contrary,
towards the pylorus they are always most conspicuous,
and often palely reddened. But no one has ever given it
as his opinion that the vascular portion of the stomach
breaks down the food, although it possesses, to demon-
stration, as much power to do so as the cuticular ; and
perhaps no one would ever have attributed such a func-
tion to the horse's stomach at all, had it not been for the
presence of this cuticular lining : it behoves us, therefore,
to examine this as well as the muscular coat. Have
* Vide Spallanzam on Digestion.

Phijsiologif of the Stomach. 505

any other parts similar coverings ? Yes ! the dorsum or
the tongue, the roof of the mouth, and the interior of
the pharynx and esophagus have ; indeed, the linings of
the two latter are continuous with — one and the same
substance with — that of the stomach; and we know for
a certainty that these organs exercise no comminu-
tive action : we believe that they are provided with
such a covering simply to defend them from the mecha-
nical irritation of the ingesta.

Let us now inquire if any, and what facts, demon-
strably true, favor the opinion of trituration within the
stomach, similar to what happens in the gizzards of
fowls. If you feed a horse with corn and grass, and
destroy him shortly afterward, you will find the former
collected in the fundus, and the latter in the pyloric
end, whether the corn have been given before or after the
grass ; in fact, it appears from many similar experi-
ments, that that food which is most difficult of diges-
tion, enters and remains for a time in the cuticular
pouch. But I have never detected any change like
trituration of it there ; on the contrary, as every one
knows, if an oat happens to be swallowed without
mastication, it will continue whole, and will be evacuated
whole in the faeces *. These facts, and the conclu-
sions I have drawn from them, beget suspicion in my
mind that all that has been said about trituration of
food in the stomach only amounts to gratuitous asser-
tion— to assertion based upon some hypothetical no-
tions, to which I cannot subscribe even though I

* Even though oats have been deprived of their husks they will
pass through indigested. Hay or straw not sufficiently divided and
crushed by the grinders, may be often detected unchanged in the
dung.

506 Physiologi/ of the Stomach.

should fail in offering any thing more feasible on the
subject.

Another particularity in the stomach, one to which
I have not till now had occasion to advert, is, that the
cuticular sac lies out of the course which that aliment
takes that passes directly from the esophagus to the
duodenum. Richerand, who has noticed this cir-
cumstance, makes the following remark. " In herbi-
vorous quadrupeds, which do not ruminate, this great
fundus (the blind pouch) forms nearly one half, some-
times nearly the greater part of the stomach, as the
esophagus enters into it very near the pylorus. In
some, as in the hog, the stomach is divided inta two
parts by a circular contraction. The food which is
received into the great fundus of the stomach may re-
main longer in that viscus, as this part of the cavity is
out of the course of the aliment." The experiments I
have briefly mentioned, relative to the transposition of
the various sorts of food, confirm the truth of this
observation ; for, the horse being an animal that is
almost always feeding, much indigested matter must
have escaped at the pylorus, along with the duly-con-
verted aliment, had not the former been so disjwsed of.
Spallanzani, whose valuable work on digestion
abounds with interesting experiments, concluded long
ago, that when the stomach contained more than one
kind of food, that which was the most easily digested
would be the soonest expelled ; and this applies to car-
nivorous as well as to graminivorous animals *. This

* M. Lallemand, however, from some observations and experi-
ments of his, h£fi come to a different conchision — " That aliments
do not escape from the stomach in the order in which they were in-
troduced, and that it is not those that arc first altered by digestion

Physiology of the Stomach. 507

author tells us, that birds are provided with gizzards
for the same reason that carnivorous or other animals
are furnished with teeth — to break down or grind their
food, in order to render it fit to be digested in the
proper stomach. " In ruminating animals, such as
sheep and oxen, which have four different receptacles
for food, the hay or grass descends immediately into
the first and second of these, in nearly the same state
in which they wei'e browsed. Here (continues Spal-
LANZANi, from whom I am now citing) they are sof-
tened by the great quantity of the gastric juices, aa
seeds in the craw of biids with gizzards. But as the
stomachs of ruminating quadrupeds have no sensible
triturating power, and the food requires trituration.
Nature has wisely provided for this by causing it to
ascend, in consequence of a gentle stimulus to vomit,
into the cavity of the mouth, where, by means of rumi-
nation, it receives the necessary predisposition to be
digested by the gastric fluid, as happens to the food in
the stomachs of graminivorous fowls, after it has been
properly triturated by the gastric muscles." In the
page preceding that from which these observations
were extracted, the author remarks, " that the horse
does not chew the cud, but resembles the ox in the mem-
branous structure of his stomach, and the food upon which
he lives. I was therefore desirous (continues Spallan-
zANi) of seeing what changes masticated plants
would undergo by continuing a certain time in the
stomach of this quadruped also, (the horse,) inclosed

that make their exit first; it is those, on the contrary, which con-
taining the least alimentary matter, are most obstinate in the diges-
tive process."

508 Phi/siologij of Ike Stomach.

as usual in tubes. Here too they were digested, as I
learned from some lettuce and trefoil enclosed in two
tubes, which were voided in fifty-two hours." Had
these tubes sustained any injury, contusion, or mate-
rial alteration of form, in their passage through the
alimentary canal, there can be no doubt but this accu-
rate observer would have noticed it : we may therefore
conclude, as Spallanzani's opinion, that the stomach
of the horse possesses no sensible triturating power;
indeed his assertion, " that the horse resembles the ox
in the membranous structure of his stomach>" amounts
to a full acknowledgment of it.

LECTURE L.

Physiology of the Stomach continued.

I ENDEAVOURED in the last lecture to shew the
invalidity of that opinion which attributes a triturative
power to the horse's stomach, alike in kind, but less
in degree, to what is possessed by the gizzards of
birds. I stated, that these organs were altogether
unlike each other ; the one being a thin musculo-
membranous bag, the other a thick and strong hollow
muscle ; that the latter was possessed by an animal
having no teeth, the offices of which it performed by
triture ; that the cuticular coat itself of the stomach
could not act, and that it existed in other muscular parts
where no such function was carried on ; that if, from
any cause, the horse did not sufficiently masticate his
food, it passed through his intestinal canal indigested ;
and finally, that my observations confinned Spallan-
zANi's inference, that the stomach of the horse resem-
bled that of the ox in having no " sensible triturating
power*."

* " It has also been conjectured that the cuticular or insensible
portion performs the office of grinding the food, somewhat similar
to, though in a less degree than, a gizzard. But, if the insensible
portion of a horse's stomach performs the office of a gizzard at all,

510

Physiologi/ of the Stomach.

It will now naturally be asked, what I consider to
be the specific use of the fundus or cuticular portion
of the stomach ? Though an opinion may be thought
precocious from me on a subject regarding which I am
ready to confess my observations and experiments have
neither been numerous nor varied enough to render me
vei*y tenacious of such inferences as I may venture
to deduce, I cannot abandon it altogether without
hazarding the solution I have formed in my own
mind of this very interesting physiological question.
As far as respects the blind pouch itself, without any
regard to its lining, it appears to have been formed
for the purpose of withdrawing a portion of the food
from the regular course of the alimentary canal, and
(Jetaining it until such time as it be fit for the operation
of the gastric juice. Now the questions are, whether the
food undergoes any changes during its stay in the fun-
dus, and, if it does, what those changes are. It is
evident that the cuticle of itself can perform no glandu-
lar function, nor do we find that the aliment deposited
in this part undergoes that conversion which it does in
the vascular end ; in which respect, the fundus bears a
similarity to the craw of the fowl*, and paunch of

( n fact which I veiy much doubt,) it must be inconceivably small in-
deed, inasmuch as we find that oats which have escaped being
crushed by the teeth, though moistened with saliva in the mouth,
and afterwards soaked with the juices of the stomach, are not
burst or broken down in this organ, but are uniformly voided
whole, in every case where the husk over which the gastric juice
has no power, remains entire. But, though we cannot say what
the peculiar office is which the cuticular portion of the horse's
stomach performs," &c. Vide Professor Peall's Work on the
Diseases of Horses, page 306.

* In birds that usually feed, on grain, as the common fowl,

Phj/siologj/ of the Stomach.

511

the ©X or sheep *. Both these organs detain the food
until ithas suffered some change, a change which, though
not absolutely necessary to its mastication and subsequent
digestion, will very materially facilitate both those pro-
cesses ; and this change appears to be purely of a chy-
mical nature — to consist in its being rendered soft by
maceration t in a mucous secretion, which is poured

turkey, pheasant, &c. the esophagus becomes dilated within the
breast, and forms a cul-de-sac, in which the food is detained until it
is softened by maceration in a mucous secretion, furnished by
glands underneath its cuticular lining, preparatory to its trituration
in the gizzard.

* In the ox (and other ruminating quadrupeds) there are four
stomachs. The first, called the paunch, a muscular bag lined by
a thick cuticle, receives the food imperfectly masticated, and with-
out commixture with the secretions of the mouth. The second
stomach called from its being composed internally of numerous
thin folds, the /loney-comb bag, is also lined by cuticle, and like the
first is but a reservoir for unmasticated food : it would appear, how-
ever, to be rather a receptacle for water, while the first contains
meat in a tolerably dry state. Now these parts are so connected
to the esophagus, that the animal can at pleasure regurgitate the
contents of the paunch into the mouth, and there masticate them,
and mix them with the salivary juices, in order to prepare them for
the digestive process: this is called rumination, or chewing the
cud. On being swallowed agam, the aliment passes into the
third stomach, denominated the viany plies, which like the second
is traversed by thin membranous folds, and lined with cuticle. The
fourth stomach, or red hag, at length receives it, and here it is that
the process of digestion may be said to be begun, and to be
nearly completed ; hence it has been designated the true sto-
mach : that this Is the case, we may infer from all the others being
covered by cuticle, from the elaborate preparation that the food has
already undergone, and from the smallness of the alimentary canal
in comparison to the capacity of the four stomachs.

t " The hay and grass descend immediately into the first and
second stomachs, in nearly the same state in which they were
browsed. Here they are softened by a great quantity of gastric

,5 12 Phi/niolngy of the Stomacli.

upon it through numerous orifices in the cuticular
coat*. By maceration, the cohesive force of the most
solid substances may be overcome, but it will not
change their nature ; added to which, we can demon-
strate that the aliment does not undergo digestion in
these cuticular sacs ; it is not very improbable, how-
^ ever, that incipient fermentation may take place in
them, even under ordinary cii-cumstances, and that it
does occasionally and to a very alarming extent in
ruminants, the disease called the hove sufficiently
proves to us; which in fact is nothing more than the
generation of air from the fermentation of green food in
the paunch t-

Now, tben, let us see how we are to apply these facts
to what happens in the cuticular portion of the horse's
stomach. Is it not probable (since we deny its trituia-
tive power) that the food undergoes here such prepara-
tory niollificalion as not only renders it perfectly innocu-
ous, in a mechanical point of view, prior to its entrance
into the sensible and vascular part of the organ, but,
also, more susceptible of the action of the gastric juice i"
The husks of beans and oats, the stalks of hay and
straw, furze, twigs of trees, &c. might, one or other of
them, prove irritating to the delicate and sensitive villi
of the stomach did they not first lie for a time steeped
in mucus in the fundus J; and that these substances

juices, as seeds in the craw of birds with gizzards." Vide Spa l-
LANZANi on Digestion.

* Spallanzani found by introducing sponge into the crop of a
turkey, that he could express from it about seven ounces of mucus,
after it had remained there ten liours.

f Vide Lecture xliv. on Diseases of the Stomach.

X The dog excites vomiting by eating grass, an effect that ap-
pears to be attributable to mechanical irritation of the villous coat of
the stomach.

Physiology of the Stomach. 513

would be more readily digested, in consequence of
being softened, no one, I should think, would be in-
clined to dispute : and now we perceive the reason
why that provender which is hardest, less digestible or
more difficult of solution than other, is lodged for a
time within the fundus. Had the stomach been lined
throughout with the vascular coat, probably the animal
would have required a paunch, ais a preparative receptacle ;
since, however, the food does not require long to be
softened, in consequence of its being already masticated
and mixed with saliva, such an inconvenient appendage
is wisely dispensed with *. In a word, 1 regard the
fundus as a dilatation of the esophagus — as a sort of
paunch or craw, in which the aliment, lying insteeped
in a mucous fluid in a certain degree of heat, not only
becomes softened, but probably undergoes a change
approaching to incipient fermentation f prior to its

* Indeed the similarity in structure, as well as function, of the
horse's stomach to the paunches of ruminaiits, is much greater than
we should at first view conceive. It is true that the capacity of
tJie cuticular portion of that of the former, bears no proportion to
that of the stomachs of the latter; but then, we are to remember
that the horse requires no receptacle for unmasticated food. With
regard to the vascular part of the horse's stomach, how much diflFer-
ence is there in the extent of it and that of the fourth stomach
of the ox?— for that is the only fair way of comparing their diges,
tive organs.

f " GossE, of Geneva, found by experiments on himself, that
animal and vegetable matters, concrete albumen, the white and
tendinous parts of anirrials, pastes made with ' fat arid butliery sub-
stances, unfermcnted or dightly fermentable matters, remain longer in
the stomach than the gelatinoiis parts of animals and vegetables,
fermented bread, &c. ; that the latter only required an hour for tH^ir
solution, while the fornier were hardly dissolved in several hours."
— " However vatious our aliments may be, the action of oiii- '

PART II. 2 L

514 Phi/sio/ogi/ of the Stomach.

being subjected to the action of the true gastric
juices. It does not seem to be absolutely necessary
that the food should undergo this preparatory process
however, nor does every kind appear to require it; for
we know that if grass and corn be eaten about the same
time, the former will (after a short detention) pass
directly through tlie stomach into the duodenum, while
the latter will remain within the fundus. Now, if we
reflect upon this fact, and bear in mind that the horse in
a state of nature is almost incessantly feeding, we shall
develope another apparent use of the blind pouch. In
consequence of its first receiving the food that is swal-
lowed, it is probable that no sudden commixture of raw
or crude matters (unless they be very digestible) with those
already in a state of digestion ever happens ; a circum-
stance that might have been productive of disturbance
and imperfectness in the digestive process, and given rise
to the escape of unchanged particles of aliment into the
intestinal canal ; for, if a horse be fed on but one and the
same sort of meat, it appears to me, that a regular and
successive supply of it is conveyed to the pyloric end,
through the intervention of the fundus, and that none
is directly transmitted into the former from the mouth
of the esophagus.

The aliment having been passed into the left, villous,
or pyloric extremity, designated by some as the only true
stomach, is mixed witli a fluid called the gastric juice,

organs always separate from them the same nutritious principles.
'There is but one food, but there exist several forms of food.'
The most nourishing of vegetable matter is the amylous fecula,
which is more easily digested, from having undergone some fer-
mentation; hence, leavened bread is the best of vegetable ali-
ments." Vide Richerand's Elements of Physiologj'.

Phifsiology of the Stomach. 515

supposed to be a secretion from the villi with which its
internal siu face abounds. Before I inquire however into
the secretion ajid properties of this fluid, and its use as a
digestive agent, it will be proper to make a few comments
on those mechanical and chemical operations formerly
had recourse to, to explain the phenomena of digestion.
Seeing that the food, soon after its admission into the
stomach, was reduced to a soft uniform mass, and that its
properties were not only a;ssiniilaled, but altogether al-
tered, the ancients conceived that this charigewas effected
in a slow and gradual manner by a process something
similar to boiling, or rather to that of maturation in the
living body, which they called coction ; but, since those
notions have been discarded by which the doctrine of
concoction was upheld, the hypothesis itself has fallen
to the ground.

In later times, fevmenlalion has been offered to ac-
count for these changes ; those, however, who have
taken most pains to develope the nature of digestion,
and are most acquainted with the process of fermenta-
tion, are best convinced of the inadequacy of the latter to
explain the phenomena observable in the former operation.
As fermentation is purely a chemical process, if digestion
were conducted on the same principles, we should be
able to imitate the latter out of the body by procuring
such fluids as are produced in the stomach : this, however,
we cannot accomplish. Again, if the food fermented,
the products ought to be such as arise from fermentation
of similar substances out of the body ; whereas, they
arc altogether different. It does happen, it is true, now
and then, that the food ferments ; but this circumstance
lends to confirm all that has been said against fernienta-

2 L 2

■516 Physiology of the Stomach,

tion, inasmuch as it is ever the result of defective diges-
tion ; and then -the products proper to fermentation
make their appearance— such as gases, acids, &c.
giving rise in the human subject to wind on the stomach,
and to hove or flatulency in horses and cattle.

Those who have discoursed of digestion as a species of
putrefaction, the experiments of Spallanzani have
silenced. That persevering experimentalist has proved,
that meat and other substances taken, or forcibly in-
troduced, into the stomach of an animal, in a state of
putridity, were entirely deprived of their putrescent
quality; and that if flesh was eaten in a recent state, it
had not time to run into putrefaction before its gastric
digestion was effected.

Of trituration and maceration, I have already spoken.
Let us now proceed to consider what are the immediate
digestive agents, as far as regards the stomach ; for it
may be here observed, that the aliment is still much
elaborated after its admission into the intestinal canal,
where the process of digestion, begun in this organ, is
perfected. From numerous experiments on digestion,
made on animals of different orders, genera, and species,
among which those of Spallanzani are chiefly enti-
tled to our consideration, it appears, that this process is
effected, as far as regards the stomach, by the action
of a peculiar fluid, with which the aliment is mixed,
called the gastric juice. In consequence of the remark-
able properties that this fluid is known to possess, va-
rious expedients have been adopted from time to time
to collect it, that its chemical composition might be
correctly ascertained : it is found extremely difficult, if
not impossible, however, to obtain it in a state of abso-

Physiologij of the Stomach.

517

lute purity *. Its peculiar power of coagulation, evei^
one is well acquainted with who has noticed the com-
mon operation of turning milk : what is called rennet
by those engaged in the business of the dairy, is nothing
more than the stomach of a calf, prepared in some
particular way, which owes its coagulating power en-
tirely to the presence of gastric juice f- So retentive is
the maw or red bag of this power, or rather so little
destructible is this property of the gastric juice by any
common operation, that the stomach may be washed,
or even dried to a skin, and it will still have the same
effect on milk. Milk then, the serum of the blood,
and any kind of jelly, introduced into the stomach, are
coagulated prior to being digested : a fact infants afford
demonstration of, when their stomachs are disordered^
in rej ecting the milk in a coagulated state. But the most
extraordinary property of the gastric juice, is that of

* Spallanzani procured it first of all, by fasting animals, and
then killing them : in this way he collected some from the gizzards
of turkeys and geese; and, after a fast of two days, thirty-seven
ounces from the two first stomachs of a sheep ; the latter was green,
obviously the effect of some plants, which still remained in the sto-
macii. In order to obtain a still larger quantity from birds, tlris inge-
nious experimentalist put bits of dry sponge into metallic tubes full
of small holes," and introduced them into the esophagus and stomach
of a crow : three of these little sponges afforded 57 grains of gastric
liquot of a turbid yellow color. This zealous inquirer next obtained a
quantity of gastric fluid by e.<iciting vomiting in himself, by means
of tickling his fauces ; the very unpleasant feelings, ho\W3ver, this
experitnent created, forbid its repetition: the ejected fluid was
frothy, sotnewhat glutinous, deposited a small sediment, and be-
came as limpid as water. . _

t To prove that this property was confined to the internal coat,
isPALLANZAifi mixed .small pieces ol the muscular arid peritoneal
coats with milk, without producing any sucTi change.

518 Physiology of the Stomach.

being — I might almost say— an universal solvent : the
liardest bones— nay even ivory itself has been eroded
and dissolved by it in the stomach of the dog. If the
solvent energy of this fluid be in an inverse ratio to the
muscular strength of the coats of the stomach *, we
may conclude that it is as potent in the horse as
in many carnivorous quadrupeds; it would appear,
however, from some experiments of Spallanzani,
that it rather exceeds in quantity than in strength in
ruminants; for in six tubes containing wheat in the
form of seed, flour, and bread, two of each sort, the
one masticated the other not, the latter were not at all
dissolved though soaked in gastric fluid, whereas the
former, which had been previously reduced to a coarse
paste, were in a great measure consumed : even pieces
of plants (according to this author) given to the ox in
this way, without previous maceration, were but slightly
affected, and their color only a little faded. That
the stomach of a horse will digest animal food has been
proved by some trials that were made at the Veterinary
College to support one on flesh alone f. It was given,

* Vide Ree's Cyclopaedia, article " Digestion."

t "Thus we read of animals naturally herbivorous, as horses,
sheep, and oxen, gradually quitting their usual aliment and learning
to live on flesh. I too can produce a recent instance in a young
wood-pigeon, a species of bird universally known to live on any
thing rather than flesh. By dint of hunger, I brought it gradually
to relish^esh so well, that it refused every other kind of suste-
nance, even grain, of which it is naturally so fond. Sucli changes,
whether effected by design or accident, will not excite the smallest
degree of surprise in those who know that, of the various kinds of
food used by man and animals, the gelatinous part supplies the
nutriment : and this exists alike in vegetables and animals. The
example of the eagle among carnivorous, and the horse or pigeon

Physiology of the Stomach. 519

by being made up into balls, for the space of a month ;
the animal, however, gradually fell away in condition,
and at length became emaciated : a result, probably,
not more attributable to the change of diet than to the
insufficiency of the quantities in which the flesh must
have been supplied. Another pecuHar quality of the gas-
tric juice, is its potent antiseptic efficacy. Putrid pieces
of flesh thrust by Spallanzani into the stomachs
of ravens, owls, &c. lost their offensive odor, and were
found to have perfectly recovered from their putrefactive
state : they underwent degrees of correction according
to the time they were suffered to remain in the sto-
mach ; but if they were confined in the esophagus, no
amelioration could be detected— indeed the contrary
was generally remarked.

The aliment, then, having been pressed, by the peri-
staltic action of the stomach and the admission of fresh
food, from the cuticular into the vascular pouch, is there
mixed with the gastric juice, which not only destroys its
remaining force of cohesion or aggregation, but exerts a
solvent power on certain parts, converting them into a
fluid, but leaving the innutritious or indigestible matters
(such as the husks of corn or fibrous parts of hay and
straw) swimming in it : this fluid, which is called chyme,

among herbivorous animals, does not however warrant us to con-
chide, that the former can be universally converted by art or chance
into the latter, and reciprocally; for, on the other hand, Reaumur's
kite and my owls and falcon were incapable of digesting vegetable
stibstances; not that these substances are incapable of affbrdmg
them nourishment, but because the gastric liquor is incapable of •
decomposing them and extracting the nutritious jelly."— Spallan-
zani on Digestion.

520 Physiology of the Stomach.

has a sour, penetrant odor, and varies its color — which is
generally green or yellow — with the nature of the aliment.
This change is earliest perceivable upon the surface of the
alimentary mass, where it first receives the impregnation
of the gastric juice ; gradually it extends in every direc-
tion until it has pervaded the whole. At this time, the
valve of the pylorus is sufficiently contracted to arrest
the escape of any gross, imdissolved matters, but the
chyme flows through as it is formed ; for, as I before
remarked, the aliment does not quit the stomach in the
order in which it entered, but according to its digestibi-
hty or convertibility into chyme. In the horse, the gas-
tric process of digestion is veiy active, and it was ne-
cessary that it should be ; for, he being an animal that
feeds beyond what in others constitutes satiety — disten-
tion of stomach, chyme must be continually flowing
out in order to make room for the aliment he continues
to take in. The duration of this process, however,
will vary with the nature of the aliment, and probably
with the age and temperament of the animal himself.
It is evident that water must flow at once through the
organ, without any detention whatever ; and we may
easily conceive how it can do so without disturbing the
contents of the blind pouch ; when it meets with solid
matters however, in its way, they are apt to be
washed through the pyloric orifice : hence it is a bad
practice to give water soon after a feed of corn ; for
indigested provender in the intestinal canal will have
the same effect as — and is indeed — so much extra-
neous matter, and in this manner the presence of oats
in the bowels may excite a diarrhoea.

I shall conclude this lecture with the relation of two

Physiology of the Stomach. B2\

experiments, which tend to confirm what has been said
on gastric digestion, by showing what passes in the sto-
mach under ordinary feeding*.

* December, 1823. A young female ass was taken up from
grass and kept fourteen hours without food or water. A quartern
of oats was then given to her, which she ate in 25 minutes. Six
hours afterward she was bled to death. The stomach contained
both grass and com ; the former occupied the vascular part, and
the boundary Hne between it and the corn which all laid in the cuti-
cular pouch, precisely corresponded with that formed by the bor-
ders of the sensible and insensible linings. The grass was dark-
colored, soft, and pulpy, and had much the appearance of chopped
or mashed boiled-spinage. The corn preserved its color, was
sheathed in a layer of mucus, was humid, and emitted a faint,
sour odor.

December, 1823. A chesnut horse (glandered and condemned)
was kept without food and water for 48 hours. A quartern of oats
was then thrown into his manger, which he ate voraciously ; six
hours and a half afterward he was bled to death. The stomach was
moderately distended with air, which, when liberated, emitted an
oifensive smell. Most of the corn was lodged in the fundus. Its
color was unchanged; though it was converted into a soft, humid
mass, consistmg of husks, kernels, and parts of kernels, from
which could easily be expressed a yellow liquor, very like the first
milk that a cow gives after calving; into which indeed the remain-
ing undissolved kernels were convertible by a little trituration
between the fingers. The vascular part was filled with this fluid,
and in it were floating numbers of the husks : many of these had the
appearance of entire oate, but on squeezing them they proved to be
empty husks. The duodenum also contained much of this fluid, but;
therein it had a whiter appearance.

LECTURE LI.

*s/- ^s«s^ ^vs^ rfsr>^ ^-^s*-

Physiology of the Intestines,

1 HUS far, I have endeavoured to develope the process
of digestion in the stomach. We have seen that the
aliment becomes therein converted into chyme, and
that the chyme passes into the duodenum. The ultimate
design of digestion, is the separation of the aliment into
nutritious and innutritions or excrementitious parts ; and
how this, the consummation of the process, is accom-
plished, we are about to inquire in tracing the progress
of the chyme through the alimentary canal.

I have already observed, that the duodenum receives
the hepatic and pancreatic secretions, and that these
enter either by one common opening, or by adjoining
orifices ; here they become mixed with the chyme, as it
flows through the pylorus : and now the process of
chylijication — the conversion of the nutritious part of
the chyme into chyle, may be said to be begun.

In my lecture on the pancreas, I remarked that it was
a gland of much similarity in structure to the salivary
glands, and that this analogy appeared to be confirmed
by a comparison of their respective secretions ; for,

Physiology of the Inieslines. 523

allhoiigli the operation of procuring the pancreatic juice
is one attended with many difficulties, enough of it has>
been obtained, I believe, to determine its resemblance
to saliva. Now we cannot for a moment entertain a
doubt that the pancreatic juice is of great — nay essential
service in promoting digestion, and yet we are, in truth,
confessedly ignorant of its precise use in the process. It
is believed by some to possess a solvent power, something
similar to that of the gastric juice, wherebyit completes the
solution of any matters that may have escaped the pylorus
in an unchymous state ; others suppose that it effects a
more perfect separation of chyle from the chymous mass.
Whether one or other or neither be its operation, it does
not appear to be so essential an agent in the production
of chyle as either the gastric juice or the bile, for in dogs
the communication has been cut off altogether between
the pancreas and duodeuum (so that the chyme was en-
tirely deprived of this fluid) without the manifestation of
any very obvious signs of impaired digestion. Far be it
however from me to imagine that Nature would have
formed a gland of the size of the pancreas, and furnished
it with an excretory duct for the purpose of conveying
its secretion into the duodenum, if some end, and that
a wise and important, though hitherto mysterious one,
had not been answered by it in the process of chyli-
fication.

Of the use of the bile we have far less equivocal
notions ; though, on this point, there has been a vari-
ance of opinion, which Mr. Brobie has gone far to
harmonize by some very decisive and satisfactory expe-
riments. This faithful observer found, that " where a
ligature had been applied so as to obstruct the choledoch
duct, (of young cats,) the production of chyme in the

524 Vkijsiolugy of the I/destines.

stomach took place as usual ; but the conversion of
chyme into chyle was invariably and completely inter-
rupted. Not the smallest trace ot" chyle was per-
ceptible either in the intestines or in the lacteals." — " 1
conceive that these experiments (continues Mr. B.)
are sufficient to prove, that the office of the bile is to
change the nutritious part of the chyme into chyle, and
to separate from it the excrementitious matter." But,
in the horse, the bile, which is poured into the gut pro-
bably at the same time with the pancreatic juice, does
not appear to exert its influence so rapidly as in carni-
vorous animals : chyle seems to be less quickly developed
as the aliment continues its passage. In this process, it
is said that the bile itself separates into two parts, a serous
and a resinous one, and that the former, mixing with the
chyle, is reconveyed with it into the circulating mass * ;
while the latter, combining with the faeces, tinges them
of a brown or yellow color, and is ejected with them as
excrementitious. To this, by some is added another
use, and one that, no long time ago, was regarded as its
principal virtue — that of acting as a stimulus to the peri-
staltic motion of the intestines, whereby a regular and
natural discharge of the excrement is maintained. The
facts, however, by which this opinion has been upheld,
appear to be of a very questionable nature : indeed Dr.
Copland goes so far as to say " that we have no more
proof that it (the bile) acts as a purge than that it per-
forms the office of an astringent. How is it (he adds)
if this opinion be correct, that diarrhoea, or a lax state of

* Dr. G; FoRDYCE, however, in his " Treatise on Digestion,"
says that the bile does not unite with the chyle itself, and pass
along with it through the lacteals hito the blood.

Physiology of the Jntestvies. 526

bowels, is so often observed during Interruptions of the
biliary secretion, and especially of the cystic bile *?"

I stated, at another time, that the horse had no gall-
bladder, and that the bile consequently passed into
the intestines as fast as it was secreted in the tubuli
biliferi of the liver : why so apparently useful a part of
the digestive apparatus, and one which is found in
most other animals f, as in the ox, sheep, dog i, hog,
&c. and in the human subject^, should be wanting in
horses, is a question of some interest ; and one which
now engages our attention. Before I proceed how-
ever to inquire why Nature has not furnished horses
with gall-bladders, let me cursorily point out what
purposes such an organ serves when present. That it
is a receptacle for the bile is sufl&ciently evident : it
invariably contains more or less of that fluid after
death ; and during life, as its secretion is probably
always going on, bile must have been continually flow-

* Richerand's Physiology, fourth Edition, with Notes and
Appendix. By J. Copland, M.D.

. f The rat and the mouse (whose stomachs so much resemble
the horse's) have no gall-bladders; the stag, the elephant, the
camel, the dromedary, and rhinoceros may be added to this list;
In the elephant, the gall-duct presents a considerable dilatation in
its course from the liver to the intestines.

X In the ox, sheep, and dog, there are several ducts which con-
vey the bile directly from the liver into the (cervix principally of)
the gall-bladder, called the hepato-cystic.

IT In the human subject there are three distinct ducts: the
ductus hepaticus, which conveys the bile from the liver, and the
ductus cysticus, which conducts it to and from the gall-bladder;
these unite, at a sharp angle, and form one common duct, called
the ductus communis choledochus, which carries the bile into the
duodenum.

526 Physiology of the hilestinen.

ing into the intestines, whether aliment was passing
or not, did not the hepato-cystic or cystic duct convey
it from the liver to the gall-bladder. Moreover, the
gall-bladder serves to improve the quality of the bile
by detaining it until its thin or watery parts have been
absorbed : cystic bile is more concentrated, viscid,
yellow, and bitter than hepatic. For it would appear
that, in those animals furnished with gall-bags, the in-
testines receive only an occasional supply of bile, but
of bile that is thicker and more efficacious than that
which comes directly from the liver ; whereas, in those
that are not there must be a continual flow of bile (sup-
posing its secretion to be going on during digestion
without intermission) of a thinner and less active kind,
into the alimentary canal : in the latter, the quantity
appears to make up for the quality.

Now, let us for a moment revert to the natural habits
of the horse. He is an animal almost always feeding; it
follows, therefore, that the stomach must be as continu-
ally expelling chyme, and that there must be as regular
and frequent an influx of chyme into the alimentary
canal*. How admirably this chimes with the uninter-
rupted supply of bile ! And equally consonant with
these facts are the apparent designs of the peculiarities
of structure of the large intestines. Whereas, in those
animals that have gall-bladders, the supply of food to
the stomach is occasional, its transmission into the

* Other animals, as I observed before, feed only at certain
times: if. they be ruminant, the intervals are employed in chew-
ing the cud ; if carnivorous, in repose. Precisely the same thing
may be remarked with regard to the evacuation of the faeces ; the
dog may void his excrement once or twice a day, the ruminant four
or five times, whereas the horse will dung every hour or two.

Pht/siology of the Jiileslines. 527

(Uiodemim occasional, and the influx of bile occa-
sional ; and so advanced is the digestive process in
the stomach, or so little further elaboration does the
aliment appear to require, that a quick and an occa-
sional peristaltic action was required.

The peristaltic action means those alternate, vermicu-
lar contractions of the muscular coat of the intestines
by which the alimentary mass is made slowly to pass
from the pylorus to the anus. These motions, which may
be seen by laying open the abdomen of a live animal
a few hours after feeding, are not performed in regular
succession, nor are they simultaneous ; the guts appear
to move backward as well as forward, and different
parts of the tube are agitated in irregular alternation.

The chyme in its course, principally in the jejunum
and ileum, is further attenuated by the admixture of a
quantity of fluid, secreted by the villous surface of the
intestines, called the succus intestinalis : this has been
vaguely supposed to be analagous in its properties to
the gastric juice. In addition to this, the chyme proba-
bly mingles with some of the mucus furnished by the
numerous follicles over which it passes.

Before I proceed further with the course of the aliment,
I shall say a few words on chyle. Chyle is a fluid re-
sembling milk, is the nutrient product of digestion, and is
absorbed by the lacteals, and by them conveyed into the
thoracic duct. It is a nice and difficult operation to
collect chyle in sufficient quantity to examine its proper-
ties ; for if we kill an animal after a full meal (which
is the only means we have of obtaining it) we must
content ourselves with what small quantity the thoracic
duct may contain at the time *. About three minutes

* The mode of obtaining chyle is this. About an hour after an
animal has been well fed, having first deprived it of sensibility (by

528

Physiology of the Intesthies.

after chyle has been let out, it coagulates ; though,
like blood, it will remain a very considerable time fluid
if confined within its own vessels. By coagulation,
it separates a thin fluid, which differs from the serum
of the blood in being white, as if a little milk had been
mixed with it ; it is analagous to serum, however, in
concreting into albumen on exposure to heat. The
solid part, like the coagulum of the blood, is com-
posed of fibrine. The following analyses of animal
and vegetable chyle were made by Dr. Marcet*.
Specific gravity 1021.

ANIMAL CHYLE.

Water .
Incipient albumen
Perfect albumen, )
slightly colored )
Fibrine
Salts

Part«.

89

4 fa

IS

VEGETABLE CHYLE.

Water

Incipient albumen
Perfect albumen .
Fibrine

Parts.

From these analyses, we find that animal chyle con-
tains more solid matter than vegetable ; it is therefore,
in that ratio, more nutritious. Another difference be-
tween them, and one in which they bear considerable
affinity to the blood of carnivorous and herbivorous
animals, is that animal chyle runs more speedily into
the putrefactive state than vegetable

pithing it or some such measure) lay open the chest, when, having
turned the right lung aside, you will perceive the thoracic duct
filled with chyle. Before you proceed further, wipe out the chest
with a clean napkin ; then, with a fine (human) lancet, puncture
the duct and collect the fluid in a watch-glass.

* The former taken from a dog fed on animal food, the latter
from one subsisted on vegetables.

f Not perfectly formed.

J Vide Part I. Lecture ii. page 17.

Physiology of the hitestiues. 529

The chymous mass having been received by the large
intestines, and its return prevented by the valvula coli, is
transmitted in part to the ccEcum, and in part to the
colon ; what portion of it the foiiner receives must be
regurgitated into the coecum caput coli, and pressed
through the colon, after the other, before it can
continue its passage : it is evident, therefore, that
the aliment which the coecum receives must be
detained for a longer time than any other. In the
human subject, there is a structure resembling in
miniatnre the pouch of the coecum ; but its size is so
inconsiderable that physiologists do not know what use
to assign to it. In the horse, the coecum is generally
supposed to perform some office analogous to that
of the stomach, and thence has been drawn a compa-
rison of it to a "second stomach." There are two
facts however that weaken this opinion : one is, that all
the alimentary matters do not pass into it ; the other,
that it commonly contains water ; I would therefore
rather regard it as a water stomach than as a digester
of food. If you give a horse a pail of water, and kill
him shortly afterwards, you will find much of it in
the coecum : this simple fact shows that it was espe-
cially designed as a receptacle for fluid. And it
does not demand much cogitation to assign a reason
why the horse should require such a reservoir for
water, when we are acquainted with his habits of
drinking. A man will drink about half-a-pint at a time,
and he will repeat this at four or five intervals in the
day ; but a horse will take in three or even four gallons^
at a draught, and will do this three or four times in
the course of twenty-four hours. With regard to the
man, his stomach can contain it ; but the greater part

PART II. 2 M

530

Physiology of the Intestines.

appears to mix with the aUment in the small intestines,
and there to become absorbed : not so in the horse, the
stomach cannot hold it, unless it be quite empty at the
moment, which it hardly ever is ; the consequence is, that
it flows into the small intestines, and the bulk of it we
find to be received by the ccecum *.

* The quantity of water consumed by a horse, will depend very
much however upon the quality of his food. A horse kept upon
green meat alone, will drink about two pailsful (six gallons) in
the course of the day; fed on dried provender, he will take a pail-
ful three or perhaps four times in the day.
A singular — nay, almost incredible cAse of polydipsia (morbid thirst)
occurred some years ago in the practice of my father, which I shall
here give his own account of " About the beginning of October,
1810, 1 was requested to visit a black gelding, the property of Mr.
Banks, of Deptford. This gentleman, who had possessed the horse
but a few weeks, informed me, that the animal had knocked up in
two or three journeys, and that of late he had reflised his food,
though he appeared to have a vehement desire for water, which, I
understood, had been allowed in but sparing quantities. The animal
showed some general signs of ill health : — his coat was long,
rough, and staring; his belly tucked up ; and he perspired freely
from moderate exercise. His principal malady, however, seemed
to be of a pneumonic nature ; to relieve which, the common
remedies, such as bleeding, blisters, &c. were resorted to : at the
same time, I recommended his having water-gruel to drink in-
stead of plain water. On my next visit, the servant complained
to me of the horse's extreme thirst, which he said was such
' that his whole time was taken up in making water-gruel ;' and
his master (probably at his instigation) wished me to take the
animal under my immediate care, (to Shooter's Hill,) which I ac-
cordingly did on the 3rd of November, by placing him at livery at
the inn opposite my house. In the course of a day or two, the
ostler discovered his appetite for drink, and represented to me that
he consumed ' all the gruel he could make for him.' At this time,
I must acknowledge, my hopes of recovering my patient (from a
malady of the nature of which I was confessedly ignorant) were

Physiology of the Intestines. 531

Now, for the sake of elucidation, let us suppose
that the horse had no ccBcum, and that its deficiency was

declining; when, on visiting him as usual on the 5th and finding
that his inordinate desire for liquids, had not by very large potations
of gruel been appeased, I resolved to ascertain, whether it was the
gruel after which he craved, or whether he had really a preterna-
tural thirst. Now, it was about eight o'clock, a. m. and he had
already taken his usual allowance of gruel, when I ordered the
man to fetch him a pail of water; this he ravenously drank,
another as greedily, a third was swallowed with equal avidity, a
fourth quickly disappeared, and a fifth followed. About a quar-
ter before one o'clock I repeated my visit, and having found my
patient by no means uneasy from the twenty gallons of water (the
pail having been measured) he had already ingurgitated, I was wil-
ling to see if he had any inclination to renew his potations. Accord-
ingly, another pail of water was offered to him, having drunk
which, apparently with undiminished avidity, he looked round in my
face with eagerness for a second; this was followed by a third, a
fourth, and a fifth : in fact, between eight a. m. and one p. m. he
swallowed the prodigious quantity of thirty-eight gallons and one
quart ! Having at length quenched a thirst which I, at one time,
almost began to despair of doing, no more water was given to
him during that day, and medicine was altogether discontinued.
This enormous ingurgitation, as was fore-thought, was speedily fol-
lowed by profuse discharges of urine ; and in this way the bulk of
the fluid appeared to have been disposed of, for no diarrhoea en-
sued, nor was there any consequent sensible perspiration."

" From this time I may date the recovery of my patient. His
appetite, before defective and declining, improved daily ; his desire
for water, though still remarkable, was not to be compared to what
it had been; for, from the 5th to the 13th of November he drank,
on an average, not more than eighteen gallons per diem; his coat,
before rough and staring, grew fine and sleek ; in fine, he became
rapidly convalescent, recovered his condition and spirits, and was
in a few weeks sent home and put to work again."

" After an elapse of three weeks or a month, I met with him
again, in harness; in the course of which interval, he had so much

2 M 2

532 Physiologij of the Intestines.

supplied in the enlarged dimensions of the colon. In
this case, the water must have been received by the colon .
But what would have been the probable consequences of
such a rapid and sudden influx into an intestine already
full, or partly so, of chylous and excrementitious mat-
ters ? This mass must have suffered such dilution that
its passage through the contracted and contorted parts
of the colon could not have been materially retarded,
or rather its stay could not have been prolonged, and
diarrhoea would have been the consequence whenever
the peristaltic action was hurried : to corroborate this,
we have only to advert to the fact of purgation being
often induced by exercise in horses whose bowels, at the
time, are distended with water. Hence, sufficient time
would not have been given for the absorption either of
the water, (which itself must have washed away chyle
from the small intestines,) or of those chylous matters
the residuary chyme may, and I conceive does, contain.
But, as it is, the water, or the bulk of it, stagnates in the
ccecum ; whence it is taken up by the absorbents, to be
ultimately excreted through the urinary emunctories : a
conclusion, the case I have just related of my father's,
I think, sets beyond a doubt. I would therefore
regard the ccEcum, I repeat, rather as the great recep-
tacle for water than a secondary stomach ; though
what portion of aliment is retained may and does un-
dergo further conversion, still it would have suffered
the same change had it at once been received by the

improved in condition and appearance altogether that I covild
hardly recognise him, as the same ill-conditioned, debilitated, hope-
less animal I had been treating so little time ago. Mr. Banks
told me, that he was still ' addicted to tippling,' hut not to any
considerable amount."

Phifsiulogi/ of the Intestines. 533

colon : I have never yet been able to discover traces of
those peculiar, gastric, digestive functions that have
been ascribed to the coecum. As will be seen from
what is past, I am also at variance in opinion with
those veterinarians who assert, that the alimentary
mass, or any part of it, must of necessity pass through
the coecum before it enters the colon.

In the human subject and in carnivorous animals, the
contents of the large intestines are generally considered
as excrementitious ; but in the horse and many other
vegetable feeders, we are not to suppose that the ends
of digestion are fulfilled as soon as the residue of
the chyme passes into the colon. It appears still to
require elaboration, not only probably for the disen-
gagement of fresh chyle, but for the separation of those .
chylous matters left unabsorbed in the small intes-
tines. Hence the great vascularity of the colon, hence
its numerous lacteals ; and now we perceive the uses
of the cells of the colon, and of its flexures, dilatations,
and contractions ; viz. to contain a large quantity of
matter, to prolong its stay, or (what is tantamount to
it) retard its passage, and to afford an extensive sur-
face for the absorption of its watery and chylous re-
mainder. That the colon, from its serpentine figure,
cavernous interior, and local diminutions of calibre,
(especially that at the commencement of the second
flexure,) will retard the passage of its inspissated con-
tents, needs no mechanical genius to discover ; and that
its cells, while they enlarge its capacity, must extend
the absorbent surface, is no less perfectly obvious.

Before it leaves the colon, the residue of the chyme,
having been deprived of its watery parts and become
tainted by the excrementitious residue of the secre-

634 Physiology of the Intestines.

tions, is converted into an inspissated fcecal mass, and
parcelled into small portions in its passage through
the contractions of the colon, which owe their triangu-
lar shape to having beeii moulded within its cells.
Having acquired a peculiar offensive fetor, which is prin-
cipally attributable to a degree of putrefactive decompo-
sition, and a color bearing more or less relation to that
of the food, the dung-balls are pressed into the rec-
tum ; which gut, with the last turn of the colon, forms
a reservoir for their temporary lodgment.

We do not find any formation in the rectum to detain
the feculent matters — on the contrary, every thing
favors their expulsion ; the intestine itself is sti*aight,
or nearly so, and increases instead of diminishing in
calibre, from its origin from the colon almost to its termi-
nation. Its use is to serve as a convenient receptacle for
the faeces, until the animal, prompted by a certain feeling
of uneasiness, or necessitated by an irresistible one of
pain, makes efforts to expel them. Having placed his
hind quarters in a certain convenient posture, the mus-
cular coat of the rectum, aided by the general com-
pression of the bowels by the diaphragm and abdomi-
nal muscles, overcomes the sphincter ani and dislodges
and evacuates the contents.

In the course of this lecture I have refrained from
any mention of the influence of the nervous system in
digestion, because the manifestation of it, though in-
disputable, is but a fact of recent development, and
because I would not run the risk of complicating my
descriptions with the present speculative though highly
important disquisitions on its nature and operation.
What follows, however, appears to be matter of fact, and
this inference fairly deducible from it — that both chymi-

On Vomition.

535

fication and chylification are, in a measure, if not
essentially, vital processes : viz. that simple section of
the nerves going to the stomach retards digestion ; that
section of them, with loss of substance, much inter-
rupts, though it does not abolish the process ; and that
narcotics, when they induce coma, occasion the like
interruption.

In conclusion, I shall offer some observations

On Vomition.

Though his power of rejecting the contents of the
stomach, is no longer questionable, it may, and with
truth, be maintained, that Nature has not endowed the
horse with the faculty of vomition : whenever it happens,
whether the act be a voluntary or an involuntary one, it
must ever be regarded as one out of the course of
nature.

An opinion has been current, that whatever a horse
vomited must necessarily all pass through his nose ; and
certainly the anatomy of the fauces appears to warrant
such a conclusion. This is a mistake however ; for the
depression of the larynx in the act of retching admits of
the escape of some of the discharged matters, and occa-
sionally of a considerable portion of them, into the
mouth. In the case of gastric tympany I have related *,
the animal had, shortly before death, three copious
liquid ejections from the stomach, much of which was
vomited by the mouth.

That we have not ready means of exciting nausea is
still more hypothetical. A dose of aloes seldom fails to
cause it, and we may at any time produce it, to any

* In a note " on the diseases of the stomach." Lecture xliv.

336

On VomitioH.

degree wu wish, and often willi llie most bciielicial
results, by the administration of white liellebore : this
may be carried so far as to excite painful efforts to vomit,
but 1 have not seen the act itself occasioned by it. Hen-
bane and wolfsbane. Professor Pea ll assures us, have
similar eff"ecfs.

Having shown that the horse is susceptible of nausea,
and that he can and occasionally does actually vomit,
through the mouth as well as through the nose, how-
ever painful and unnatural the effort may be to him, I
shall now agitate the old question — why he has not
naturally the faculty of vomitioii. On this subject,
M.GiRARD (p^ie) has written a " Memoir *" which
contains so much practical and conclusive information
that I cannot resolve the question in a more explanatory
and satisfactory manner than by translating that part of
it which relates to the horse.

M. GtRARD commences his Memoir by observing
that " Vomition in domesticated herbivorous quadru-
peds, is a veritable phenomenon, an extraordinary
effort, always accompanied with more or less pain ; and
so much the more important to become acquainted with,
since it is either the signal of a sudden restoration of
health, or else that of approaching and inevitable
dissolution."

After examining the stomachs of the dog and hog, and
those of omnivorous animals in general, and comparing
them in relation to their shape, structure, and position j
M. GiRARD deduces this inference — " From this short
exposition, it would appear that vomition is performed

* " Memoirc sur Le Vomissement contrc Nature clans les Herbi-
vores Domestiques," appended to his " Anatomic Veteriiiaire."
Par J. GiRAKD.

On Vornition.

537

with more or less facility according as the antiperistaltic
motion, the efficient cause of the operation, is uniformly
conducted from one extremity of the stomach to the
other, and as it is thence readily propagated to the
esophagus : this is no hypothetical inference, but one
that appears to be very conclusive, if a comparison be
made of the stomachs of carnivorous animals v^^ith those
of herbivorous monogastrics, which last are justly re-
garded as not having the faculty of vornition." — The
Professor now remarks, that the horse's stomach is
much cui-ved, and deeply lodged under the crura of the
diaphrag-m, at a considerable distance from the abdo-
minal muscles ; that it is so loosily attached that it
varies its position with its volume, and that this posi-
tional variation is favored by the curvation made by the
esophagus within the belly, one about three inches long,
which is received into a fissure of the liver ; and further,
that when it grows large and stretches backward, this
esophageal prolongation is something lengthened and
more or less straightened, whereas the contrary happens
whenever the stomach re-approximates the diaphragm.
" The most important characteristics," continues Gi-
RARD,^ "of the stomachof the horse, compared with those
of the dog and hog, regard its structure. The esophagus
is inserted about the middle of its small curvature,
and consequently very near the pylorus. In piercing
the coats of the stomach, it takes an oblique direction,
as the ureters do in entering the bladder. Within the
stomach, it forms a little furrow which runs very
obliquely, and imperceptibly vanishes : this anatomical
mechanism at once explains why convulsive actions in
the stomach rather tend to contract than dilate the
cardiac orifice. From a little posterior to the place

638

Oil Vomition.

where the crura cross the aorta to the stomach, the
muscular membrane of the esophagus becomes imper-
ceptibly pale, stronger, thicker, and remarkably firm :
this part maintains a permanent state of constriction,
which is only overcome by substances passing into the
stomach." This membrane is continued upon the sto-
mach itself where its fibres are so disposed that the
cardiac portion possesses the greatest powers of resist-
ance and contractibility.— Internally, the lining of the
stomach may also impede indirectly the retrogade pas-
sage of the aliment by the folds it is thrown into, which,
GiRARD is of opinion, have a valvular operation.

" These divers considerations show, that the circum-
stances that unfit the horse, the mule, and the ass, to
vomit, essentially depend- -first, upon the mode of
insertion of the esophagus into the stomach ; secondly,
upon the particular disposition of the muscular mem-
branes of these organs. All other causes are but acces-
sory, or but indirect in their operation."

The remaining part of this Memoir is devoted to the
detail of some interesting experiments and cases, illus-
trative of what has been said, the transcription of which
would spin out this lecture to too great a length.

LECTURE LII.

On Purgation and Purgative Medicines.

By catharsis or purgation is meant, the operation of
certain medicinal substances which stimulate the intes-
tinal canal to evacuate its fsecal contents in a liquid state,
and in greater quantities or at shorter intervals than under
ordinary circumstances. These substances are deno-
minated cathartics or purgatives. The number of them
in use in veterinary practice is veiy inconsiderable when
compared to the catalogue displayed in the therapeutics
of the surgeon ; but before I proceed to particularize
them, I shall take a summary view of the theory of pur-
gation.

In the administration of cathartic medicine we have
two objects in view. The one is, and one, says Dr.
Hamilton *, from which I can hardly suppose that
debility will ensue, to bring off the contents of the
bowels, which are out of the course of circulation, and,
in so far, are already in a manner extraneous to the
body ; the other, to excite a determination of blood to
the internal surface of the intestinal canal, in order
that some of it may be evacuated in the form of secre-
tion. This latter is what is meant by a full purgative

* " Observations on the Utility and Administration of Purgative
Medicines." By James Hamilton, M.D.

540 On Purgation and Purgative Medicines.

effect ; the former, what is understood by a gentle pur-
gative operation : some practitioners however limit the
meaning of the word purgative to the first, and deno-
minate the latter a laxative.

The modus operandi of a cathartic may be thus briefly
explained. Supposing it to be aloes, as soon as it has
undergone solution, partial or entire, in the stomach,
it irritates and reddens the vascular lining, and aug-
ments, if not alters, the gastric secretions : from which
disordered condition of the organ arise nausea and
loathing of food. Secondly, it stimulates the lining of
the intestinal canal, and this is followed by accelera-
tion of the peristaltic action, whereby the contents are
hurried onward to the anus, and by an augmentation,
if not alteration, of the intestinal juices, which is the
principal source of the liquidity and profuseness of the
evacuations. Thirdly, cathartics in general appear to
increase the influx of the biliary and pancreatic secre-
tions : an effect that further contributes to the quantity
and fluidity of the discharged matters.

I shall next cursorily point out the healthy states, and
some of the diseased or disordered conditions of body, in
which we are in the habit of administering cathartic me-
dicines. For purgatives are sometimes given in health as
preparatives or auxiliaries to putting horses in condition ;
whereas they are never given in disease but to remove that
which is the cause of the malady, or that which has more
or less influence in its progress or continuance. The sim-
plest view we can take of the exhibition of a dose of ca-^
thartic medicine, is the expulsion of the fcecal contents of
the large intestines in a sliorter time than they otherwise
would have been discharged : this is what is called
" unloading the bowels," and is the principal intention

On Purgation and Purgative Medicines. 541

in purging horses that have been recently taken up
from grass. But, it is scarcely possible thus to limit its
operation ; for even every laxative that we administer,
must in some degree augment the intestinal secretions,
if not the biliary and pancreatic as well, and thus
remotely be productive of other consequences. When
we improve the condition of a horse in apparent health
by the administration of alteratives, or laxatives, or
cathartics, we are said to accomplish it by urging the
various organs employed in the digestive process to a
more vigorous performance of their functions ; but if
all the amelioration the animal's constitution has evi-
dently experienced be duly estimated, this confined
reasoning appears to be inadequate and unsatisfactory :
there would seem to be disorder or derangement present
somewhere in the system in all these cases, the removal
or rectification of which, either temporary or perma-
nent, was the remote effect of the medicine, and that
on which its salutary efficacy depended. How much
do a few well-timed doses of laxative medicine contri-
bute to restore the condition of a poor horse — how in-
fluential soihng is in inducing a thriving diathesis, and
promoting fatness and sleekness, and every other ap-
pearance indicative of robust health— and yet these
ameliorated states probably were not preceded by any
signs whatever of disorder or disease ! And it is in the
alterative and laxative forms that cathartics are so be-
neficial in promoting health that appears to be flagging :
in fact, they are effectually under such circumstances
veritable tonics.

There are certain manifestly disordered states of body
also in which laxatives are preferable to purgatives in
full doses. In all cases of habitual pursiness or thick-

542 On Purgation and Purgative Medicines,

ness of breath, (from previous organic disease,) in broken
wind and in permanent roaring, in evident imperfection
of the digestive process, and in some cutaneous affec-
tions, their judicious exhibition will often be found to
be eminently serviceable.

Of the direct effects of a full dose of cathartic medi-
cine on the system, we have pretty satisfactory evi-
dence. Not only does it influence the general distri-
bution of blood by causing a preter-natural determina-
tion to the abdominal viscera, but its operation is
attended with a greater consumption of that fluid, in
consequence of there being an augmentation of the
intestinal and probably other secretions. And when we
calculate the extent of the secreting surface of the ali-
mentary canal, and take into our consideration that
there may be an augmented afflux of other secretions to
it, in addition to its own, we shall be able to form some
idea of the loss of vital fluid the system may sustain in
this way : nothing, indeed, can evince to us the debi-
litating effects of cathartics more strikingly than the
quick depression of condition, and with it strength and
spirits, which supervenes upon excessive purgation.
Even as a depletive therefore, next to blood-letting,
catharsis is the most potent remedy we possess ; and it
is chiefly with the intention of determining blood to the
bowels and of drawing it off in the form of secretion,
that we employ purgation in most inflammatory dis-
eases.

I shall now enter upon the consideration of those
substances that are employed as cathartics in veterinary
practice, and shew their doses and medicinal properties
as far as my own experience, united with that of others,
has ascertained them. And here it would give me great

On Purgation and Purgative Medicines. 543

satisfaction to display a list equal in variety and utility
to that available in human medicine ; but I am com-
pelled to set out in my investigation with the dis-
closure of this extraordinary fact — that of all the sub-
stances that have been introduced from time to time
into medicine, or discovered to be poisons, only two are
generally admitted to be safe and efficient as cathar-
tics when administered to horses : and one of them, in
this country, is quite a recent production. It is true
that in most old, and in some modern veterinary
works, there are other substances prescribed as cathar-
tics ; indeed, in some of the former, there are as many
and as various formulae for purges as might be desired ;
but, unless their principal and efficient ingredient is
aloes, either they possess no such power at all, or;
they are uncertain and even dangerous in their opera-
tion.

Aloes, till lately the only serviceable cathartic, still
probably the best in our pharmacopeia, appears to have
been long known to farriers, grooms, and others, who
have been in the habit of giving from an ounce to two
ounces at a dose ; so that twenty or thirty years ago,
before veterinary science had become diffused, a
prevailing cause of fatality was super-purgation : and
indeed, at the present day, to over-doses and injudicious
regimen many horses fall victims that are said to have
caught cold or to have received injury from spurious me-
dicine. Aloes is a drastic purge, and one that for general
purposes, I repeat, appears to be equalled by no sub-
stance with which we are acquainted ; the space of time
however it requires to produce its cathartic effect, and the
acrid and irritating qualities inseparable from it, render
it objectionable and inadmissible in some special cases in

544 On Purgation and Purgative Medicines.

practice. It has been said, that we cannot purge a
horse in less than twenty-four hours, but that we
can open a man's bowels in two, or even one. As
this remark however is grounded upon the effects of
aloes on the horse and neutral salts on the man, the
comparison is by no means fairly drawn ; and to prove
that it is not, there are medicines that will purge a
horse in half that time, and we know that if a man
take a bolus of aloes over-night it will rarely operate
before the following morning. It is rationally deducible
from its length and peculiar conformation that the ali-
mentary canal of a horse will not permit that quick
passage through it that ours will ; and from the attempts
that I have made, by experiment, to produce a less tardy
purgation, though the practicability of it can be de-
monstrated, I am very much inclined to come to these
conclusions : — that the production of catharsis in a
less space of time than twenty hours, will not be un-
attended with risk ; and that this risk will increase into
danger as the means we may use may shorten this or
some such inteiTal.

In veterinary medicine an infeiior kind of aloes is
made use of : — either the hepatic or Barbadoes, or
the caballine or Cape aloes. Some practitioners are in
the habit of exhibiting the former, some the latter —
each party maintaining their comparative efficacy and
superiority by an immediate reference to long and
incontrovertible experience. Though I am no reverer
of experience myself when it rests upon practical affir-
mation alone, if I were called on to arbitrate this point,
I should say, from all that I have been able to collect,
that these apparently contradictory opinions were both
well grounded, and that if practitioners would take the

On Purgation and Purgative Medicines, 545

trouble attentively and impartially to examine the
aloes, and the subjects to whom, and the circumstances
under which, they prescribed this or that aloes, there
would soon cease to be any difference of opinion upon
so plain and palpable a point of practice. Private
practitioners in general, I believe, are in the habit of
making up Barbadoes aloes ; the Veterinary College,
and the whole of the Cavalry and Ordnance Veterinary
Establishments are (and always have been) supplied
with Cape aloes.

The dose, under ordina,ry circumstances, is six drams
of Barbadoes aloes or seven of Cape aloes j for, whether
the latter be obtained from the dregs or sediment of
the former, or whether it be a distinct variety, there
certainly does appear to be this difference in their ca-
thartic virtues : a circumstance of itself, I have no
doubt, that, for want of advertence to, has contri-
buted to keep alive the discordant reports of their com-
parative efficacy. It is a common and a commenda-
ble practice to introduce into the cathartic ball some
essential oil or aromatic ingredient ; for this has the
two-fold effect of imparting an agreeable odor to it, and
of counteracting its harsh or griping effects upon
the bowel *. Though six or seven drams, however, is
what I consider a medium or standard dose, it is evi-

* These formulae may be indiscriminately exhibited.
R Aloes Caballina; 3vij.

01. Esscnt. Menth. Pip. vel Carui gtt. xx.
Saponis Duri 3j.
Theriacae q. s. ut f. Bol.

vel,

Aloes Barbadensis 3vj.
Saponis Duri 3j.
Syrupi Zingiberis q. s. ut f. Bol.
PART II. 2 N

54G On Purgation and Purgative Medicines.

dent that this must be constantly varied according to
the size, make, age, condition, and apparent strength
or constitution of the animal. Should the horse be
strong and bulky, we may, as a general rule, in the
ratio in which he is so, augment the dose to one dram,
two drams, or even three ; on the other hand, should
the subject be slender or diminutive, we shall have
occasion to reduce the dose. Horses with large bellies
and circular chests in general require a dram or a dram
and a half more of aloes than those (equal in height) of
an opposite conformation ; and if they have past their
fifth year, and are " full of hard meat," they will en-
dure the operation of strong cathartics ; but if they
are heron-gutted, narrow-chested, out of condition, or
have been recently taken up from grass, the very same
doses may be followed by super-purgation and death.
Peculiarity of constitution also is not to be entirely
overlooked. Professor Coleman, in his lectures,
used to make mention of a horse of his own that would
purge from the administration of three drams of Cape
aloes; Mr. O'Connor, V. S. Newmarket, informed
me, that a thorough-bred filly of his, only three years
old, although she undement three or four days' prepa-
ration, required fourteen drams of Barbadoes aloes to
produce the ordinary cathartic effect under every ad-
vantage of exercise and dilution, and that a particular
insusceptibility or torpor of bowel had been remarked
in the progenitors of this filly. I may add however,
that racers in general, in consequence of the high
feeding and strong exercise they are inured to, require
large doses of purgative medicine-

When we purpose to administer a full dose of cathar-
tic medicine to a horse whose state of health does not

Oh Purgation and Purgative Medicines. 547

require its immediate exhibition, we commonly diet
him — what is termed prepare him beforehand. We
feed him during the preceding day, sometimes for two
or three days before, on bran or bran mashes in lieu of
corn ; for bran, like green meat, is easily digested, is
not long retained in the bowels, and requires less sti-
mulus to expel it than either corn or hay ; so that a
somewhat less dose of aloes is sufficient when this pre-
parative regimen has been observed. Supposing then
that the horse has been mashed over-night, the purge
should be given early in the morning, either at least
two hours after he has been, or the same time before he
shall be, watered, and not less than an hour before he
shall be fed : in the course of the same day he may be
moderately exercised. The principal part of his food
should now be scalded bran — bran mash, either warm
or cold ; though some hay, but no corn, may be al-
lowed him : during the summer I have not been in the
habit of forbidding green meat. Water, before it is
given to him, particularly in winter, ought to be made
of the temperature of the stable. Warm clothing,
under such circumstances, in cold situations, is always
highly desirable.

The space of time in which aloes produces purgation,
cccteris paribus, will depend upon the state of the bowels
at the time of its administration, and upon the regimen
that may be adopted during the interval— prior to its
operation. Bowels, the contents of which admit of
being made soluble by mashing, and have already
been rendered so by bran or by green food, will often be
affected in twelve hours; whereas those that have
been habituated to an astringent provender— to old
hay and oats and especially to beans, will often require

2 N 2

548 On Purgation and Pin-gative Medimies.

thirty and even forty hours to be moved. The opera-
tion itself will be principally influenced by the regimen
we may pursue at the time, and mostly by exercise and
by watering. If the medicine should not take effect
on the following morning — twenty-four hours from its
administration, which is generally the case, first give
the animal as much water as he will drink, and then
walk him out briskly for about an hour or an hour and
a half, unless he purges ; for as soon as his evacuations
have become liquid and frequent, he ought to be re-
turned into the stable, littered down, and plentifully
supplied with water: warm or cold mashes may be
offered to him, but at this time he will seldom show a
disposition to feed. Should he however at the expira-
tion of his exercise not purge, he will probably eat a
mash on being led into the stable, and be inclined to
drink again : at all events, I would give him at this
time no hay. During the succeeding four hours he
should continue quiet in the stable, and be offered
water hourly, and then, if he continue unmoved in
his body, taken out and exercised a second time ; and
now. after having walked for half an hour without the
desired effect, he may be first gently and then pretty
briskly trotted : I wish it to be understood however,
that he ought not under any circumstances be made to
gallop. The old maxim was, to exert the animal " un-
til he purged or sweated ;" but were we implicitly to
follow this quaint rule, I am inclined to think with Pro-
fessor Peall, that it would in some instances prove
" the last trot or gallop the animal could be made to
perform ;" for all violent means to increase the peristal-
tic motion must evidently have a tendency to excite
inflammation of the bowels. When we first perceive

On Purgation and Purgative Medicines. 549

any signs of purgation, or of laxity — the prelude to it,
we may often, by the subsequent regulation of exercise
and watering, control to a considerable degree the ope-
ration of the medicine ; we may (when we have appor-
tioned the dose nicely) allow it to pass off with a laxa-
tive effect, or we may suffer it to produce its full opera-
tion ; and we may save an over-susceptible or over-dosed
animal from super-purgation and its pernicious conse-
quences * : all this therefore shows the great advan-
tages derivable from paying attention to exercise and
dilution. In the course of the third day, generally
speaking, the dung passes in soft but consistent masses,
and then it is said that " the physic has set ;" on the
fourth day the faeces commonly re-appear of their globu-
lar shape, from which period the animal may be gradu-
ally inured to his ordinary work.

The time then taken up in subjecting a horse to a
full dose of purgative medicine, is three days : — on
the first it is administered, on the second day it ope-
rates, and on the third it sets ; for the three or four
following days however the horse cannot be said to
have completely recovered from the disturbance it has
created in the system ; and hence the practice, when
two or three doses are about to be given, unless under
circumstances of disease, of making the interval be-
tween them not less than a week, is a very necessary
one, both as regard the safety of the succeeding dose
and the benefit derivable from that last administered.
Not, however, that I subscribe to that vulgar and ab-
surd, and till lately to me unaccountable practice, of un-
exceptionably giving three doses, by way of preparation.

• Vide Lecture on Diarrhoea.

550 On Purgation and Purgative Medicines.

to horses that are to be put into condition ; I say till lately
inexplicable, for a friend of Professor P e a l l 's, a veterinary
surgeon, to whom I beg leave to express my obligations
on this occasion for saving me much fruitless research
and probably some unfortunate inferences, received the
following syllogistical statement on this abstruse point
from a groom, an enthusiastic admirer, as well as a
strict follower, no doubt, of the humoral pathology :
— "The first dose merely stirs up the humors, the
second sets them qfioat, and the third carries them all
off!!!"

As CASTOR OIL is Said on good authority to be an
useful cathartic, while others aver that it is not more
efficacious as such than so much common or olive oil,
I shall give the result of my experience of these sub-
stances. To a horse that was constitutionally healthy
and had been mashed the preceding day, Ibiss. of castor
oil was given at ten o'clock, a. m. He purged seoen
hours after, and continued to purge all the next
day. To a farcied horse Ibj. was given at half-past
nine o'clock, a. m. who had been mashed over-night.
He was exercised thrice during the same day without
any signs of purgation ensuing. At three p. m. he be-
came dull and languid, refused his food, and had an
accelerated pulse. These symptoms hourly increased :
— at nine p. m. his pulse was 70*, his abdomen was
contracted, he stood with his hind legs advanced under
his body and his back roached — " all of a heap :" in
fact, he appeared to be suffering much abdominal
pain, though it was not acute enough to produce symp-
toms of gripes. These symptoms continued with little
variation until seven p. m. the next day, at which time
he passed the first liquid evacuation. On the third

On Purgation and Purgative Medicines. 551

day, his dung, which he voided but seldom, was soft ;
these evacuations however always appeared to relieve him.
His health was not restored for several days afterwards.
In order to form some comparison between the medicinal
quaUties of castor and common oil, a glandered horse,
whose general health was good, was subjected to this
experiment. His food being hay only, first he took
Ibj. of the sulphate of magnesia dissolved in Ibiss. of
water, without effect. On the fourth day after this,
Ibiss. of castor oil was given to him. Thirty-two hours
after his dung, which had previously appeared in
balls, fell in small, irregular pieces, as if preparatoiy to
purgation ; no signs of that state of bowel, however,
or of uneasiness followed. On the fourth subsequent
dayj Ibiss. of olive oil (second quality) was adminis-
tered. Next day the dung-balls became soft and were
united in masses ; but no symptoms of purgation en-
sued. In order to ascertain to what degree this horse's
bowels were susceptible of the operation of cathartics,
on the third day from this, 3v. of Cape aloes were
given to him. In the coui'se of the following day he
experienced brisk and profuse purgation. The simila-
rity of circumstances under which these several sub-
stances were exhibited was scrupulously preserved.
From these and other experiments I have come to these
conclusions: — 1. That castor oil, as a cathartic, in
doses of Ibj. and Ibiss, is either inefficacious or very
uncertain — not to add unsafe or even dangerous in its
operation. 2. That olive oil, in the same doses, is equally
unserviceable as a cathartic. 3. That sulphate of magne-
sia, in the dose of Ibj . possesses no cathartic property
whatever. My father, who had previously exhibited these
medicines in large doses separately with similar results.

662 On Purgation and Purgative Medicines.

gave to a horse (destined to slaughter) 01. Ricini Ibij . c.
Magnes. Sulphat. Ibj. solut. in Aqua. On the following
morning (twenty-four hours after) no effect having
been produced, the same dose was repeated. Towards
night his bowels became gently moved ; but in the
cotirse of the night excessive purgation came on, which
was accompanied with nausea, loathing of food, and
symptoms of irritated bowels, and which the next day
ended in death.

Linseed oil however, I have been respectably in-
formed, is a certain and a powerful cathartic. I have
seen it given to five horses, at different times.
Two of them took it in doses of Ibss. In one it pro-
duced purgation in twenty hours ; in the other, it only
relaxed the bowels : they were not exercised. In two
others who were drenched, each of them, with Ibj. of
the oil, it took no perceptible effect whatever. A horse,
about to be destroyed for acute glanders, took Ibiss. of
it. Thirty hours after he purged without exer-
cise or mashes ; and his evacuations strongly impreg-
nated the atmosphere of the stable with the peculiar
disagreeable odor of the oil : the purgation continued
throughout the third day, and then set without any
unfavorable symptoms. I am by no means satisfied
however about the invariableness and safety of its ope-
ration as a cathartic : on the contrary, until I have had
an opportunity of investigating its medicinal properties
further, I shall not prescribe it myself but by way of
experiment.

Gamboge is certainly possessed of drastic cathartic
properties, but as a medicine nearly the same objections
appear to be applicable to it. 3ij. of it purged one horse
in twenty-four hours as violently as if he had taken an

On Purgation and Purgative Medicines. 553

ounce of aloeS. Another was taken off his feed by 3iss.
but not even relaxed in his body. To three other horses
were given doses of sij. In thirty hours after, one ap-
peared nauseated and relaxed a httle ; but no subse-
quent purgation took place. Balls, each of which were
compounded of siij. of gamboge and gtt.xij. of the
essential oil of carraway, were given to three other
horses. Though not one of them was purged, the medi-
cine so much disordered them that they refused their
food during the following day, were tucked up, dejected,
and apparently in much uneasiness or pain from it.
To a horse glandered and farcied, 3iij. were given one
morning and repeated on the following one. On the
third morning the animal was seized with great prostra-
tion of strength, had great difficulty in rising when he
had lain down, and his pulse was very frequent and
scarcely perceptible ; but he did not purge. Several
days elapsed before the animal recovered his wonted
appetite, strength, and spirits. At the expiration of
which (a week) he was destroyed. The vascular lining
of the stomach shewed marks of intense inflammation,
as also did that of the intestines, though in a less de-
gree.— I look- therefore upon gamboge, as I do upon
many otlier medicines which, it cannot be denied, pos-
sess considerable cathartic power, as an uncertain, an
unsafe, and in certain doses a virulent medicine ; and as
one not only of doubtful efficacy, and therefore unser-
viceable in common practice, but as a purge that
ought to be banished altogether from our pharmacopeia.
I have often thought though that it might prove an
useful adjunct to aloes, but I have never made trial
of the combination.

Lastly, it is probably expected that I say something

554 On Purgation and Purgative Medicines.

about a newly-introduced cathartic medicine which for
potency of operation far surpasses any one that has
hitherto been made trial of : I allude to the Croton
Tiglium. I need not enter into its natural history, nor
stop to inquire who first exhibited it in this countiy :
Mr. Hodgson informs me, that it is known and used
in India, its native soil, as a purgative to horses ; and
Mr. John Field, Junior, V. S. London, has, with a
promptitude and professional liberality which demand
my particular acknowledgments, favored me with such
communications as have enabled me to write with a de-
gree of confidence and decision upon its medicinal
properties, for which information those who are un-
acquainted with its virtues must also hold themselves
professionally indebted to the experimental researches
and extensive opportunities of that gentleman. It
appeal's that in India, where the tree is cultivated on
account of its purgative qualities, both the wood and
seeds are medicinally used ; but I believe that the seeds
are the only part of the plant that has as yet been admi-
nistered in this country. Mr. Hodgson tells me, that
the natives are in the habit of roasting the seeds, which
process is found to render them less acrid and violent
in their operation ; and that a celebrated physician in
India prescribes a seed so prepared to be made up
with six grains of calomel into four pills, two of which
he generally directs to be given at bed-time, and the
remaining two after an interval of twelve hours, unless
the bowels be affected. And Mr. Hodgson gave, at
Calcutta, gi-.xxv. of the roasted seeds—joomalgota, as
the Indians have named the plant, to a young healthy
horse, that was exercised and fed as one under the
operation of aloes. At the expiration of thirty hours

On Purgation and Purgative Medicines. 555

the animal passed an evacuation like cow's dung ; dur-
ing the twenty-nine succeeding hours, without any
further exercise, he had twenty-three discharges of the
same consistence. Another horse that took gr.xxx. be-
gan to purge after twenty-five hours, and continued to
pass liquid evacuations for two-and-a-half days : solid
dung also came away at intervals.

There is another tribe of plants — the jatropha, the
seeds of one species of which, the jatropha curcas, in
Hindoostanee bagbarinda, seem to be allied in their
cathartic qualities to those of the croton. Mr. Hodg-
son says, that in India two or three of these seeds (not
roasted) constitute a dose for a man, and that he has
given them to horses, but that his experiments turned
out too inconclusive to hazard any deductions.

The croton seed, as is well knoyyn, in the dried
state in which it is imported, is about the size of a tick
bean, is oval-shaped, and of a dark brown color. If
it be split open, it will be found to consist of a strong
capsule, inclosing a yellow, soft, and an oily kernel,
between which is a light-colored pellicle that adheres
to both, but more closely to the latter, apparently
through the intervention of a furfuraceous volatile
powder which is very apt to fly into the eyes and fauces
in splitting the capsule, where it does not fail to occasion
considerable irritation. The kernel itself is composed of
an oil mostly separable by expression, making up about
one-fifth of its weight, and of a farinaceous residue, con-
stituting the remaining four-fifths, which, from being
caked by expression, requires to be triturated, and is
then presented to us in the form of a hght brown olea-
ginous farina.

Though every part of the seed possesses the purgative

656 On Purgation and Purgative Medicines.

quality, the capsule appears to be the least active when
given internally. Mr. Field exhibited ^ij. of it to a
cart horse vpith no more effect than had been previously
produced upon the animal by gr.xl. of the farina.

The oil, which has lately been admitted into the
London pharmacopeia, is now considered to be one of the
most powerful drastic purges used in medicine ; it has
however maintained so high a price that, were it recom-
mendable, it could not be introduced, as a general cathar-
tic, into veterinary practice. I should say that the
average dose of the oil was gtt.xl. and that this might
be with caution and discrimination increased to a dram.
One hor^ to whom a dram was given, was most
violently purged in twenty-four hours after. Mr.
Sewell gave 3ss. of the oil to an ass about a twelve-
month old, and the following morning, no effect having
been produced, 3iss. more : this was followed by pro-
fuse diarrahcea and symptoms of excessive irritation of
bowel, which ended in death. The mucous coat was
found intensely reddened throughout the intestinal canal.
In a word, from what I have observed myself and been
able to collect from others, I should say that the oil was
most unquestionably a cathartic of great power, but
that its efficacy was not of that certain and definite cha-
racter which would warrant its arbitrary exhibition in
practice : indeed, I cannot divest my mind of the idea
of a species of virulence about it which seems to unfit
it for common use.

Unless it be exceeded in this virtue by the furfuraceous
powder sticking about the pellicle, the farina has been
found by Mr. Field to possess the cathartic quality in
the most eminent degree : and this is the part which
that gentleman is now in the' habit of exhibiting with a

Ot Purgation and Purgative Medicines. bbl

degree of certainty and safety not inferior to aloes it-
self. It may be given in powder, or in tincture, or in
aqueous suspension. In powder, Mr, Field considers
gr.xxx. of it to be equivalent in efficacy to 3vj. of
Barbadoes aloes ; and this we may, in a general way,
regard as the rule whereby we are to dispense it —
reckoning gr.v. as equal to 3j. of the aloes.

The TINCTURE Mr. Field makes, by macerating,
for two or three days, ^j. of the farina in 3j. of rectified
spirit, and then filtering the solution. By this process
the farina is deprived of its cathartic virtue, and we
have a clean, and an elegant preparation, either for in-
ternal or for external * use. But if the tincture is
mixed with water, the mixture becomes cloudy, and a
white filmy precipitate slowly forms and subsides, which
Mr. Field believes (for he has not yet ascertained the
fact) to be the same substance— the purgative essence
extracted by the spirit from the farina : if this be the
case, it would be desirable to obtain this sediment in a
separate state, for it might turn out to be a highly con-
centrated cathartic preparation. When the thicture
however is first thrown into a large body— a pailful of

* Oil of turpentine will also deprive it of its essential property, and
thereby acquire a highly stimulant power. By macerating 9j.of the
farina in 5j. of oil of turpentine, Mr. Field found that he had ob-
tained a verj- acrid irritant to the skin ; for, by rubbing the hip of one
of his cart horses with this solution, and the opposite hip with the
same quantity of plain oil of turpentine, he found that the solu-
tion, in the course of four-and-twenty hours, had excited not only
exquisite tenderness but considerable tumefaction, which ended in
desquamation of the cuticle and separation of the hair, whereas
the turpentine itself only occasioned a little tenderness and irrita-
bility which in a short time altogether subsided.

. 558 On Purgation and Purgative Medicines.

• water, the precipitate is so small and becomes so much
diffused that it will remain for many hours in a state of
suspension, and thus a sufficiency of it to purge may
be voluntarily drunk by the animal if he have been kept
for some time previously deprived of water.

I think that enough has already been said to convince
every unprejudiced mind of the fitness of croton for a
place in our pharmacopeia : were it only for the small-
ness of the dose, and the variety of forms and com-
pounds in which it may be exhibited, it could not fail
to prove occasionally serviceable, when aloes was inad-
ministrable, both to the public and private practitioner ;
and more particularly to the latter, who has now an
opportunity of sheathing a common purge from the im-
pertinent inquisitiveness of his knowing employers. In
a scientific point of view however, we ought to experi-
ence other advantages from it before we subscribed to
its real utility in practice ; for if it differs not in its
effect or operation from aloes — if indeed it does not pos-
sess some advantage as a cathartic over that medicine,
then, as such, it is not worth our consideration : to say,
that to deserve notice it ought to surpass aloes, is too
absurd to merit a reply. The first question then is,
does croton differ either in its operation or effects from
aloes? — the second, if it does differ, does it advan-
tageously and availably so in practice ? — and upon the
answers to these questions I think every unbiassed
inquirer will form his opinions. Croton takes ca-
thartic effect in about the same space of time that aloes
does — certainly not sooner. But, Mr. Field has ob-
served that it does not create those signs of nausea and
sickness which are so generally induced by an aloetic
purge; and that, when it does operate,' the evacua-

On Purgation ami Purgative Medicines. 659

tions are more profuse and watery, in consequence of
its emulging more intestinal secretion, which is followed,
as might be naturally expected, by greater and more
permanent debility of system. It therefore may be
given, I should presume, with advantage over aloes in
disease when it is an object to thoroughly scour the
bowels and sensibly deplete by catharsis ; and in health,
to large, gross horses, overloaded with flesh, that we
wish to put speedily into condition. On the other hand,
Mr. Field has not found that the exhibition of croton
is followed by those beneficial effects upon the digestive
organs which are so conspicuous after well timed and
regulated doses of aloes : here, then, it falls short,
not of our expectations, but of the expectations of those
who assay every new cathartic they meet with by the
standard of a medicine of which, if it were their mis-
fortune, by any accident, to be deprived in the exercise
of their profession, they might lament and say with
our matchless bard —

" You take my house, when you do take the prop
That doth sustain my house ; you take my life,
When you do take the means whereby I live."

END OF PART II.

\* The Series of Lectures will be concluded in </m; Third Part.

J. niLL, rniKTEH, 57, PATEnNOSTEn ROW.

Critical Testimonies in favor oj -the ViRsr Part of these
Lectures.

" THERE is an interest attached to the anatomy' and physiology
of the horse, proportiosate to the value of the animal to man, inde-
pendantly of the study gf jts structure and vital economy as an
object of comparative anatomy. Great encouragement is therefore
given to the improvement of the veterinary art by opening all the
resources of medical science to its professors and their pupils. Con-
sequently, the education of students of farriery is placed upon the
same footing as that of the students of our anatomical schools.
Thus, whilst the art acquires dignity, the rank and emoluments of
the veterinary surgeon partake more of the advantages enjoyed by
practitioners in human medicine than formerly."

" We rejoice in any indications of a disposition to rescue the
treatment of our domestic animals from the barbarism with which
it has been so long envejoped, and to substitute practical deductions
from rational principles for remedies sanctioned by the experience
of grooms and jockeys."

" We look forward with pleasure to the completion of this work.
It will, no doubt, prove an useful book in the hands of those for
whom it is chiefly compiled ; and we recommend it to gentlemen
who are not disposed to trust the care of their hflrses' constitutions
to farriers and grooms, and who are desirous of acquiring a know-
ledge of the principles which form the basis of the veterinary
treatment of our domestic animals." The London Medical and
Thijsical Journal, No. 295, September, 1823.

" To the practitioner in medicine, whether physician, surgeon,
or surgeon-apothecary, the horse is an object of peculiar attention.
This noblest of all animals is the medical man's attendant and de-
voted servant in all his rounds — transporting him from place to
place, through sun and rain, by day and oy night, with mie.xampled
alacrity, patience, and expedition."

" We can have no doubt but that the book is very well adapted to
the veterinary student, and that it is the most scientific, as far as
it yet goes, of any work emanathig from a similar source." The
Medico-Chirurgical Review, No. 15, Decetiiber, 1823.

" The author of this work appears to be well informed in the
principles of medical science. He has viewed, in a very satisfactory
manner, the physiology and pathology of the horse, in relation to
the laws which regulate the human economy, and, indeed, animal
bodies generally. As far as these recommendations may entitle it
to regard, and as far as we are capable of judging of its merits
generally, we consider it a work of considerable excellence." The
London Medical Repository, No. 115, Juli/ 1, 1823.

" Mr. W. Percivall has lately published a very able Series of
Lectures on the Veterinary Art, which afforded me much pleasure
in the perusal. Though redolent of the theatre of dissection, they
may be considered as the best specimen of the ' ^.tyiaray lAxQuifAO.'
of the Veterinary Art, that has hitherto issued from the press, and
must be of essential service to all Students of the profession. —
NiMROD." Sporting Magazine, No. 75, December, 1823.

I