Glasgow University Library

GUL 68.18

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PART THIRD

OF A

SERIES

OF

ELEMENTARY LECTURES

ON THE

VETERINARY ART:

WHEREIN THE

ANATOMY, PHYSIOLOGY, AND PATHOLOGY

OF THE

HORSE,

ARE

ESSAYED ON THE GENERAL PRINCIPLES

OP

iWelrfcal defence*
— ♦

sy

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 anatomes peritus, quia snb hoc medico et artifice, omnia tutissime
et felicisaime peraguntor," — Fahricius ab Aqua})endente.

" Morborum qnoqne te cansas et signa docebo." — Virgil.

LONDON:

Published by

LONGMAN, REES, ORME, BROWN, AND GREEN,

Paternoster Row.

1826

ENTERED AT STATIONERS' HALL.

mix, PRINTER, 67, PATERNOSTFR HOW.

CONTENTS.

LECTURE LIII. Pages
On the Kidneys — Capsule Renal es — Bladder. 1 to 14

LECTURE LIV.

On the Physiology of the Urinary Organs 15 — 29

LECTURE LV.

On Diuresis and Diuretic Medicine — Diseases of the Urinary
Organs 30 — 47

LECTURE LVL

On the Testes and Vesiculae Seminales 48 — 63

LECTURE LVII.
On the Penis and Prostrate Glands .- , 64 — 75

LECTURE LVIIL
On the Female Organs of Generation 77 — 93

LECTURE LIX.

On the Physiology of the Organs of Generation, Male and

Female ......rr ....«•.. 94 — 113

LECTURE LX.

OaCastration 114 •— 131

vi CONTENTS.

LECTURE LXI. Pages
On the Appendages of the Eye 132 to 153

LECTURE LXII,
On the Eyeball 154 — 179

LECTURE LXIII.
On Vision 180 — 202

LECTURE LXIV.
On the Diseases of the Eye 203 — 236

LECTURE LXV.
On the Dissection of the Brain and Spinal Marrow 237 — 259

LECTURE LXVL
On the Origin and Distribution of the Nerves . » 260 — 276

LECTURE LXVII.
The Subject continued 277 — 288

LECTURE LXVIIL
The Subject continued 289 304

LECTURE LXIX.
On the Distribution of the Arteries , 305 321

LECTURE LXX.

The Subject continued 322 335

LECTURE LXXL
The Subject continued , , 335 ggg

CONTENTS. VU

LECTURE LXXII. Pages
On the Distribution of the Veins 354 to 372

LECTURE LXXIIL
On the Distribution of the Absorbents 373 — 386

LECTURE LXXIV.
On Fever 387 — 405

LECTURE LXXV.
On Mange and other Cutaneous AfTections — Grease 406 — 428

LECTURE LXXVI.
On Staggers— Strangles 429 — 445

LECTURE LXXVII.
On Glanders and Farcy (Professor Coleman's Opinions) . . 446 — 464

LECTURE LXXVIII.
The Subject continued (Professor Dupuy's Opinions) .... 465 — 502

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VETERINARY LECTURES.

LECTURE LIIL

Having concluded my observations on the chylo-
poietic viscera, I shall take up the consideration of
those employed in the secretion and excretion of urine,
the URINARY ORGANS as they are generally called,
beginning with

The Kidneys.

The kidneys are two reddish ovoid bodies, situated
in the lumbar regions, whose office it is to secrete the
urine.

In consequence of the kidneys not receiving perito-
neal tunics*, it is usual to regard them as extra-abdo-
minal ; custom however appears to me to be somewhat
capricious on this point, for they are certainly as much
within the cavity as the pancreas, and may, anatomi-
cally viewed, with equal precision be included among
the viscera of the abdomen : indeed, they cannot be

* Vide Part II. Lecture xlii. " Reflection of the Peritoneum."
PART III. B

2 ■ The Kidneys.

properly examined in situ but from within the abdo-
minal cavity ; where they are found a little further
backward than the pancreas, immediately above (or
concealed by, as the horse lies upon his back,) the
small intestines. They repose, one upon either side,
in beds of adipose and cellular substance, by which
principally they are retained in their places, beside
the bodies of the lumbar vertebrae, or rather under-
neath the psoaB muscles, to which they are firmly
attached by this substance, as well as to the vertebrae
themselves. Their anterior ends reach under the last
ribs ; posteriorly they come in contact with the cristae
of the ilea ; and to both these parts they are also tied
by cellular membrane. They receive some support
from the peritoneum as it passes under them, and are
attached by it to the contiguous viscera ; but their
strongest connection is to the spine through the me-
dium of their blood-vessels. The right kidney has
peritoneal attachments to the right lobe of the liver,
and to the head of the pancreas ; the left has a
similar connection with the blind pouch of the sto-
mach, from the pressure of which in a state of dis-
tention it is pushed a little further backward than the
right : the left is also tied to the pancreas and to the
spleen.

The jfigure of the kidney varies remarkably in dif-
ferent subjects : nay, the right is commonly unlike the
left, is less elongated and broader ; in fact, it is a
gland that does not appear to possess any very deter-
minate form : generally speaking it may be said to
represent an irregular flattened oval ; but it is an
imperfect oval, one side is interrupted by an inlet or

c deficiency of substance, technically called the notch,

/

The Kidneys. 3

into which the blood-vessels are received. The uuioui-
tude of the gland, not less uncertain than its form,
estimated by its weight, may be stated in round
numbers to average forty ounces.

To enable me to be more particular and explicit in
my description, I shall divide the kidney into its
upper and under surfaces, its border, and its notch.
The under surface, the part covered by peritoneum,
under which is interposed a partial layer of soft yellow
fat, is partially divided into two unequal lobes by a
fissure running directly across from the notch towards
the circumference ; in many subjects the upper divi-
sion is in part subdivided by a smaller fissure, which
also proceeds transversely from the notch, into two
portions : still it is one continuous or conglobate body,
which is not the case in bears and in the cat tribe,
where these lobes, being perfectly distinct, constitute
it a conglomerate gland. The under surface has also a
middle transverse fissure, but it is less in extent ;
sometimes we find two or three others, but they are
small and unworthy of notice. This is the part
bedded in adipose matter ; but the quantity of adeps,
though considerable in very fat subjects, is inferior to
what is found in the herbivorous ruminant, in whom
it concretes after death into a remarkably white, firm
mass, well known by the name of suet. Now, that the
gland is inverted, the notch is brought more into view :
in some subjects this forms a considerable breach in
the body of the gland, in others it makes Only a part
of the transverse fissure aforementioned ; it is designed,
like the porta of the liver, to give ingress to the blood-
vessels and egress to the duct belonging to the gland.
The border, thick and rounded, narrows and describes

B 2

4 The Kidneys.

the segment of a circle anteriorly ; broadens and
extends into a larger arc posteriorly : by adverting to
this circumstance, and attending to the distinguishing
characters of the surfaces, the kidney of one side may
be known from that of the other when they are both
removed from the body.

The kidney has a capsule of its own which is every
where adherent to its surfaces through the intervention
of a very delicate cellular tissue, and this tissue may
be traced in places into the glandular substance ; at
the notch processes also come from the capsule that
accompany the renal vessels and nerves throughout
their ramification, and serve at once as an additional
tunic to them and a suitable connecting medium
between them and other parts.

The interior of the kidney is rnost adeptly exposed
to view by carrying a horizontal section through its
middle in the line of its long aris. The surface
exposed by this section exhibits two colors, which,
though perfectly distinct, are shaded into each other
by a broad intervening circle of dark red ; the outer
part has a brownish red tint, and is denominated the
cortical substance, because it surrounds the medullary or
tubular substance, as it is called, which has a carnation
hue, growing lighter as it extends inward. These
substances not only differ in color, they differ in con-
sistence, in disposition, and in structure. The cortical
part has an uniform appearance something like that of
the liver, and possesses a texture comparatively soft
and easily lacerable ; the medullary is much closer and
tougher in its composition, and evidently possesses eI
fibrous texture : they are not conjoined in any regular
line, but dark-red denticular prolongations of cortical

' The Kidneys. 5

shoot between the lobulated portions of medullary
substance.

Though the ultimate organization of the kidney can-
not be demonstrated with absolute certainty, it would
appear from the researches of anatomists in general
that there is less speculation interwoven with the
accounts commonly rendered of it than is blended
with those of other complicated glandular structures.
Injections sent into the emiilgent arteries color the
cortical substance, but are not to be detected in
the medullary ; a simple fact that has led to the con-
clusion that the former is principally composed of
blood-vessels : at least this is the common result of
the experiment. To pass over the detail of the means
however whereby we have attained our present know-
ledge, the minute structure of the kidney appears to
be this : — The several divisions into which the emul-
gent artery splits in penetrating the substance of the
gland, 6nd in a multiplied number of smaller arteries,
and they form arches within the cortical substance
from the convexities of which a still smaller set come
off : these minute vessels proceed inward, few (if any)
of them reaching into the medullary part, and end in
little globular bodies that have been resembled to the
acini of the liver and named the corpora globosa : a
sort of arterial arrangement altogether that has been
resembled to grapes as they grow upon their slender
stalks. The corpora globosa were at first supposed to
be cellular ; but later researches afford us reason for
believing that they are constituted of the vessels con-
nected with them, which, instead of terminating in
them, are prolonged and coiled into these globular
forms. From the corpora globosa proceed inward iu

6 The Kidneys.

convergent radii, fasciculi of minute vessels named from
their office the tubuli uriniferi ; which fasciculi are so
disposed in sets (commonly six or seven in number) as
to admit of a resemblance to so many paps or dugs,
and hence have been denominated the processus mam-
millares. These conical fasciculi, which take their rise
in the cortical part, constitute the medullary substance
of the kidney. The papilla or apices of the mammil-
lary processes are received into little membranous sacs,
varying in form and size, named the infundibula, into
which the urine is distilled through the orifices of the
tubuli uriniferi perforating the papillae : the number
of infundibula however is not regulated by that of the
processus mammillares, for one sac may embrace two
or even three papillee. The infundibula, contracting
in their course, converge towards a common centre
until they open commonly by three canals into the
pelvis, whose orifices are large enough to admit the
small end of a common blowpipe. The pelvis is the
common receptacle of the fluids transmitted through
the infundibula ; it is situated about the centre of the
gland, almost surrounded by medullary matter, and
consists of a dense, firm, membranous substance, form-
ing an extended sac which is continuous towards the
interior with the infundibula, towards the notch con-
tracted into a small funnel-shaped outlet having one
continued passage with the ureter : this continuity of
parietal parts has led some to consider the infundibula,
pelvis, and ureter, as one and the same extended
structure ; whether this be the case or not, they pos-
sess a common mucous lining that puts on the same
aspect examine it in which of these parts we may.

The ureter, emerging from the pelvis, descends
t( J

/

The Kidnei/s, 7

out of the notch and then suddenly turns backward
under the posterior end of the gland, passing between
it and the capsula renalis ; it then takes its course
directly backward, a little distance laterally removed
from the bodies of the lumbar vertebrae, crossing ob-
liquely the psoas parvus and afterwards the great iliac
vessels ; here it enters the pelvis by a sweep upward
and outward (embracing within its concavity the vas
deferens and ligamentum rotundum) and becomes
included within the fold of the ligamentum latum, by
which it is conducted to the lateral and superior part
of the bladder ; latterly, it runs in close connection
from the middle of the bladder half-way to its neck
and then imperceptibly vanishes between its tunics.
Though we insensibly lose sight of the tube however it
does not end here, for after having obliquely pene-
trated the muscular coat it travels onward for the
space of an inch between that and the internal coat,
and at length terminates by piercing the latter in the
same oblique line of direction. The diameter of the
ureter near its origin is equal to that of a large-sized
black-lead-pencil, from which it so insensibly dimi-
nishes in calibre throughout its course that we are only
assured of the fact by comparing the anterior with the
posterior portion. That part of the tube not included
within the broad ligament is invested with cellular and
adipose tissue which binds it down in its course. It
is composed of two tunics. The external one is thick,
resisting, and longitudinally fibrous, and is believed to
be muscular : the internal is soft and fine in its tex-
ture ; is commonly rugose lengthwise ; is loosely adhe-
rent to the other ; and is constantly besmeared within
with a mucous secretion to shield it from the urine.

8 The Copsula Renales.

The emulgent arteries, right and left, arise in front of
their respective glands from the sides of the posterior
aorta; each enters the notch, and there divides into
three, or four, or even five principal branches, which,
unlike the trunk, bend in their course and then pene-
trate the glandular substance ; the outer branches
turning in contrary directions, one forward the other
backward, to enter the cortical part at once ; those in
the middle traversing the tubular to arrive at it ;
in which they all subdivide and ramify as afore
described.

The emiilgent veins, which exceed in dimensions
though not ordinarily in number the arteries, corre-
spond in their ramification to those vessels : their
principal branches, three, four, five or upwards in
number, converging within the notch, there unite into
one trunk which accompanies its artery and ends in
the vena cava posterior.

The 7ie7'ves are derived principally from the renal
plexus, and very numerous they are : notwithstanding
their numbers however, and notwithstanding the acute
pain which accompanies active inflammation of it, the
organ in the healthy condition is by no means remark-
able for its sensibility.

The Capsula Retiales

Are two small, elongated, irregularly-formed,
brownish bodies, a right and a left, placed opposite to
the kidneys, between those glands and the spine. The
right, the longer one, lies in contact with the pos-
terior vena cava, and reaches forward to the liver ;
the left, the broader one, and rather obliquely placed,
is opposed to the aorta, and anteriorly is contiguous to

th

The Copmla- lienales. 9

tlie pancreas : they arc respectively connected to these
several parts by loose enveloping cellular substance,
and are furthermore retained in their places by the
peritoneum which covers their under surfaces. Their
magnitude varies with age : in early foetality they are
equal in volume to the kidneys themselves ; their sub-
sequent growth however being less rapid than that of the
kidneys, this equality in the course of time becomes
destroyed. Their outward borders are partially cleft
by several little notches which give them a lobulatcd
appearance. They possess tunics of their own of con-
densed cellular membrane which penetrate beyond the
surface and enter into the composition of their interior.

When lengthwise divided by a perpendicular sec-
tion, the renal capsule shows a palish brown substance
above and below, which is interspersed with vessels
and nerves, is soft and uniform in its texture, and com-
poses full two-thirds of its whole ; and in the middle
a longitudinal whitish part, which, though of a very
loose texture, is evidently not a vacuity ; for, after
some yellowish fluid it commonly contains is expressed
there still remains a loose or cellular structure. The
fluid expressible from this part is said . to vary in its
appearance and quantity with the time of life : in the
foetus it is said to be red and abundant, yellowish and
sparing in the adult, yellower still and more scanty as
age advances. This body receives two or three small
vessels from the emulgent artery or aorta or from both ;
and these have their full proportion of veins. They
have also an adequate supply of nerves coming princi-
pally from the renal plexus. Wliat the disposition or
arrangement of these several component parts may be
remains yet to be developed ; M. Girard says, con-

10

The Bladder.

cerning them, that, although these bodies are plenti-
fully furnished with blood-vessels and nerves, " ils n'of-
frent dans leur organisation aucune disposition qui
puisse faire presumer une secretion particuliere."

The physiology of the capsulae renales remains to
this day an unsolved problem. Not one fact has been
related to light us in the investigation. All that
Haller's indefatigable research and penetrating mind
could discover for certain about them, was, that they
secrete a fluid more required in foetal than adult life,
and that their functions are probably important since
they are found in so many animals.

The Bladder.

The musculo-membranous bag that receives the
urine from the terminating orifices of the ureters.

The bladder occupies the middle and inferior part
of the pelvis, takes the oblique axis of that cavity,
and rests upon the symphysis pubis, having the rectum
over it in the male, the vagina in the female. In the
undistended state this viscus is wholly confined to the
pelvic cavity ; but when full its fundus advances
before the pubes into the abdomen, the advancement
being in ratio with the distention : in the foetus it
rises still more into the abdominal cavity, as a neces-
sary consequence of its proportionally greater develop-
ment, and the narrowness and shallowness of the pelvis
at that period.

In a state of distention the bladder is pretty regu-
larly pyriform, and its parietes are thin and semi-trans-
parent; but when completely empty it assumes the
spheroid figure, and becomes thick and has no vacuity
internally : in fact, it is in that state a little white,

The Bladder.

11

round, firm, and, I may add, solid body. Its capacity
will vary much in different subjects ; and this we have
reason to ascribe principally, from a correlative fact in
human anatomy, to the habit the animal had of retain-
ing the urine ; for it is found that women, whom we
know from motives of delicacy are oftentimes com-
pelled to restrain their inclinations to void their urine,
have generally larger bladders than men : and now
and then in such subjects bladders are found of extra-
ordinary volume.

The bladder is connected by loose cellular adhe-
sions to the pubes, the walls of the pelvis, and the
rectum in the male, the vagina in the female ; but
it is balanced in its proper place and position by
two broad productions of peritoneum expanded across
the cavity from its sides to the walls of the pel-
vis, called its ligamenta lata. These are formed
thus : the peritoneum being reflected upward from
the recti muscles upon the body of the bladder about
its middle, proceeds forward upon the fundus, then
turns back again and covers still more extensively the
upper surface ; at the sides these (under and upper)
layers of the membrane, meeting together, unite and
afterwards proceed in union to the walls of the pelvis,
where they once more split and take opposite direc-
tions. The middle portion of the upper layer of peri-
toneum is reflected upward from the hind part of the
body of the bladder upon the rectum in the male, the
vagina in the female, and thus a peritoneal pouch is
formed between the two. In addition to these attach-
ments, the neck of the bladder is connected to the
pubes by a thin fibrous expansion, the ligamenlum Iri-
aiigulare ; and the fundus receives the insertion of two

12 The Bladder.

round cords which run within the folds of the broad
ligaments, named the Ugamenta rotunda.

The bladder may be distinguished in description
into its fundus, body, and cervix or neck. The fundus
is the round and prominent part presented forward,
is completely covered by peritoneum, occasionally pro-
trudes into the abdomen, receives the attachments of
the round ligaments, and the insertion of the degene-
rated urachus ; (which is in the foetus a urinary conduit
continued along the umbilical cord to the membranes
of the womb). The body is the bulky or capacious
part of the bag ; only one-third of its under surface is
covered by peritoneum, nearly the whole of its upper ;
it is supported by the broad ligaments, has along its
sides in the male the vesiculse seminales and vasa defe-
rentia ; and behind grows suddenly contracted and
ends in the neck. The cervix is the small, circular,
posterior part of the bladder ; it has a light-pinkish
hue, and is comparatively thick and substantial to the
feel ; it has the triangular ligament fixed to it, and is
united at the opposite end to the urethra.

The bladder has three coats : an external one which
is derived from the peritoneum ; a mucous membrane
to which it owes its integrity and principal consistence ;
and a diffuse fibrous texture interposed between the
two which is of a muscular nature. The peritoneal
coaty which forms but a partial covering, is smooth,
polished, and moistened with serous exudation exter-
nally ; but rough and pilous internally, when it is torn
from its adhesions with the muscular : in a word, it in
nowise differs in its properties from the peritoneal
tunics of the abdominal viscera. It serves to hold the
bladder in its proper place and position, and to a

The Bladder.

13

certain stretch to counteract preternatural distention
of it.

The muscidar coat, though it may be demonstrated
through the pellucid peritoneum, is brought more dis-
tinctly into view by stripping ofF that membrane, to
which it is closely and firmly attached by fine cellular
tissue. Pale fasciculi are then seen running irregu-
larly in a longitudinal manner ; and, underneath them,
others which are smaller, taking an equally irregular
course in the circular direction : in the empty or half-
distended state of the oroan both these orders of fibres
assume spiral courses ; this enables them to bear consi-
derable extension without the risk of rupture, while their
cellular connections, being loose, admit of their being-
drawn apart with equal facility. The longitudinal
fasciculi are thickest about the fundus, where they all
converge to its central point ; the circular are strongest
around the cervix : the former exert a special contrac-
tion in forcing the urine towards the neck, constituting
what has been called the detrusor uriiKC ; the latter,
which are ming-led with cellular tissue and some small
veins, giving them the feel of greater substance than
they really possess, form the sphincter vesica of those
who (with no more reason in my opinion) make a sepa-
rate muscle of this part. By the united and regular
contraction of both orders of fibres the parietes of the
bladder may be drawn towards one common centre so
as pretty equally to diminish its capacity in every part,
until the cavity is altogether annihilated.

The mucous coat shows itself exteriorly in the inter-
spaces between the fasciculi of the muscular, covered
only by the interposed cellular tissue which serves as
the common uniting medium of all these tunics. When

14

The Bladder.

the bladder is empty the contractions of the muscular
throw this coat into ruga, which in cases of extreme
contraction assume rather a remarkable appearance :
the cellular tissue interposed between this and the
middle tunic is loose to admit of this, and, from its
being pressed into a pretty regular layer wherein the
vessels and nerves of the organ ramify, it is described
by some as the nervous coat. The internal membrane
is white, soft in its texture, and highly organized ;
besides which it possesses numerous follicles from
whose excretory pores issue a plentiful mucous secre-
tion to defend it from the acrimony of the saline
matters contained in the urine : this mucous matter
being perpetually washed off the surface by the urine
is kept continually renewed ; and it is occasionally
voided in considerable quantities, especially when any
calculi or other irritants are present in the bladder.
About an inch before the cervix, in the sides of the
bag, are seen the mouths of the ureters, whose oblique
insinuations in perforating the parietes operate in pre-
venting any reflux of the urine at the time that the
bladder is contracting, and thereby have completely
the effect of regular valves.

LECTURE LIV.

On ike Phifsiology of the Urinary Organs.

The kidneys are entitled to our earliest considera-
tion as being the organs in which the fluid we call
urine is elaborated from the circulating blood. Were it
required of us to adduce argument or evidence in
support of so palpable a truth as this has become in
physiology we need not seek long for either. The
bare anatomical examination of the urinary apparatus
altogether, conducted by one conversant with the gene-
ral principles of the animal economy, is perhaps enough
to raise suspicions of such a nature in the mind ; but
when the emulgent artery comes to be compared with
such vessels as the hepatic, the coronary, and the
bronchial, which are considered to be the nutrient
arteries of the parts to which they are respectively
going, and these parts come to be individually con-
trasted in bulk with the kidney, it does not appear
unreasonable to draw an indirect inference at once that
secretion of some kind or other must be carried on in
this body, since the blood sent to it far exceeds the
quantity necessary from analogy for the purposes of
nutriment and repair. Setting aside all hypothesis

16 On the Pliyaiology of the Uiiiiuri^ Organs.

and analogical deduction however, we have indisputable
evidence of the facts, that urine is produced in the kid-
ney, and that it passes thence through the ureter into
the bladder. Diseases that suppress the functions of
the kidney, caculous concretions obstructing the pas-
sages, and a fortiori ligatures upon the ureters, arrest
the urinary discharges : during any such morbid or
unnatural condition of these parts not a single drop of
urine is found in the bladder ; in the former case there
is none secreted ; in the two latter the fluid collects
between the place of obstruction or ligature and the
kidney, distending and dilating even to disruption the
mammillary processes, infundibula, pelvis, and ureters.

In this manner may be demonstrated the secretion
of the urine in the kidneys and its passage into the
bladder ; a knowledge no sooner attained by an inquir-
ing mind than the questions, how and by what parti-
cular parts of the organ the secretion of it is effected,
naturally follow in this interesting investigation. So
long however as our knowledge of the minute anatomy
of secreting organs remains so imperfect, so long as we
continue unable to connect particular glandular struc-
ture and arrangement and action with the particular
nature and composition of the secretion resulting there-
from, so long must these questions go unanswered ;
and though in the instance of the kidney, as I stated
before, we have been more successful we think than
in most similar researches, still the amount of this
information does not appear to have been in the least
enhanced by the circumstance. We suppose that the
urine is secreted within the corpora globosa by the mi-
nute ramifications of the emulgent arteries, and that the
tubuli uriniferi receive it from these bodies ; and we

On the Physiology of the Urimny Organs. 17

know that afterwards the infundibuUi collect it from
the mammillary processes and discharge it into the pel-
vis, whence it is carried by the ureters into the bladder.

The blood is here, as everywhere else, the pabulum of
secretion ; but it would appear from some facts touch-
ing the process and from the known composition of the
urine that the serum was the part mostly expended in
its production. Water forms the bulk of both these
fluids ; and they contain saline substances of a similar
nature. What are called the serous exhalations in
the body, and especially that from the membrane
lining the bronchia, influence to a certain extent the
urinary secretion ; hence it is that dropsical subjects,
in whose systems there is such a disposition to serous
effusion, make but scanty discharges of urine ; and
hence it is that by setting up a reversion of ac-
tion in favour of the kidneys we get rid of the dropsy.
But the most remarkable sympathy of function of this
description exists between the skin and the kidneys,
and it is one/that also tends to show that urine is prin-
cipally obtained from the thin or aqueous parts of
the blood. In warm weather when animals per-
spire much there is very little urine voided, and the
reverse of this happens in cold weather ; men have an
opportunity of remarking this in their own persons,
and it is well known to coachmen and others in the
habit of riding or driving that horses who sweat pro-
fusely seldom stop to stale on the road ; indeed so
sparing is the secretion in some instances that when
such horses are put into stables to induce staling they
void so small a quantity that they are occasionally
imagined to labor under what is called " a stoppage."
This then is what we understand by sympathy between

PART HI. C

18 On the Fhysiology of the Urinary Organs.

the skin and the kidneys ; in this manner is there a
sort of equihbrium of function maintained between the
emulgent and perspiratory vessels. Again, it is found,
coeteris paribus, that the quantity of urine will be regu-
lated by the quantity of water drunk. The horse who
drank within the space of a few hours thirty-eight
gallons of water*, shortly after deluged his stall with
urine \ for, as I observed before, this prodigious ingur-
gitation was not followed by purging, though had he
been taken out and sweated a considerable proportion
of it would have passed off by perspiration ; and this is a
case that not only throws light on the aqueous nature
of the secretion, but it also shows us what an enormous
bulk of fluid may be excreted from the system in a
very short space of time in the form of urine. We
might a priori suppose that the serum would also vary
its proportions with the quantity of fluid imbibed :
Professor Coleman many years ago made this ex-
periment to determine the point. He kept a horse for
several days without any fluid whatever; and after-
wards permitted the animal to glut himself with drink.
Now the horse was bled during the continuance of
thirst, and at different intervals after he had drunk
five or six pails-full of water ; and yet the Professor
could discover no variation whatever in the proportion
of the serum to the crassamentum. The urinary dis-
charge was but little during the time of drought, but
returned copiously on a sudden after the animal had
satiated his extreme thirst : from which it appears
that the watery constituents of the chyle are not
permitted to continue in the circulating mass, but are

* Vide Part 11. Lecture li.

On the Phj/siologj/ u/ the Uiinun/ Organs. 19

speedily separated therefrom; and that the kidneys
in cold weather, but the skin when it is warm, are the
principal emunctory for its discharge.

The shortness of the intervals between the taking
of a copious draught and the consequent augmentation
of this secretion, and between the swallowing of food
and the detection of that food by certain properties it
happens to possess in the urine, has led some physio-
logists to think that there must exist a more direct
passage to the bladder than the regular round of
lacteals, circulation, and kidneys. No such special pas-
sage however has ever been discovered ; and even if we
imagined that there were absorbents that could serve
such an office the hypothesis must be supported by the
very serious and responsible admission that there
exists a power in the alimentary canal to form urine.
Independently of all this however, the bare fact that
obstructed ureters and an empty badder are consequent
and unalterable conditions of those parts, though the
evidence be but negative, is sufficient to refute the
above conjecture.

This secretion is one that is constantly going on ;
by night as well as by day, during hot weather as well
as cold, whether little or much or even no water at
all be drunk, though its quantity will be considerably
influenced by these circumstances, urine is continually
passing from the kidneys into the bladder : of this we
may at any time convince ourselves by leaving a
catheter in the bladder, or by referring to those cases
on record, both of malformation and disease, in which
the ureters have opened upon the surface of the human
body. It is not so with secretions in general ; we have

c 2

20 On the Physiology of the Urinary Organs.

reason to believe that supplies of bile, semen, pancrea-
tic juice, 8cc. are only furnished as occasion requires.

Fear and anxiety of mind have a remarkable effect
on this secretion in the human subject, and the same
influence is equally striking among animals. It is by
no means an uncommon occurrence upon a race-ground
to meet with a racer and his jockey who are said to be
"leaky before starting;" on which occasion I should
argue that the feelings of the horse and man were not
widely different. Again, what fox-hunter has not seen
many horses in the field staling at the time that the
hounds were finding in the thick of the covert ? or who
has not seen a cur do the same thing at the sight of a
horsewhip ?

Another distinctive character of this secretion is the
extreme variableness of the product. In health this is
too remarkable to have escaped the notice of the most
casual observer ; and in disease it may be ranked
among those phenomena which remind us how little
we yet know of primary or proximate causes. It may
be observed in a general way that the greater
the quantity of urine secreted, the paler, less acrid
and odorous it is ; and so far imbibition affects its qua-
lity as well as quantity : indeed the urine that rapidly
follows a copious draught is in so diluted a state tha^
it has the appearance of being little else but pure
water, and so has been denominated crude urine or
urina potus. But the urine which is voided a few hours
after feeding, when the food has had its chyle extract-
ed by the lacteals, or that which has been long secret-
ing, is high-colored, acrid, and emits a pungent fetor ;
it is in fact strongly impregnated with the urinous

On the Phi/sio/ogi/ of the Urinaty Organs. 21

properties and such as a chemist would choose for
analysis were he about to examine its composition :
this has been distinguished as the urina chj/ii or con-
cocted urine. But, independently of this variation,
which may be compared to simple dilution of it, the
quality of the urine will be affected by the kind of
food consumed by the animal, and in some instances
in so remarkable a degree partake of its properties that
we may determine the nature of the ingesta simply by
examination of the urine. In the human body, garlick,
onions, asparagus, carrots, and some other vegetable
substances, impart to this fluid peculiar recognisable
fetors ; and beet root and madder alter its color : I do
not know that any one has made any such observa-
tions among horses, but I should not hesitate to predict
similar results were their food materially altered ;
horses in general are fond of carrots, and will feed upon
Swedish turnips, beet root, and mangel wurzel, so that
the experiment might easily be made. The effects
of change of diet however are in no instance more strik-
ingly illustrated than in diabetic persons when the
plan of treatment consists in restricting them to animal
food: Professor Coleman once kept a horse for many
days upon flesh balls, but I am not aware that any
particular notice was taken of the urine, since the
experiment was made with other views than what en~
gages us here. Certain medicinal substances also are
known to affect the urine : aloes heightens its color,
turpentine imparts to it a terebinthine odor, but what
impregnates it with the most pungent and offensive fetor
of any thing that I have ever given is the balsam of
copaiba ; during its exhibition the stable is rendered

22 On the Phi/siologi/ of the Urinaria Organs.

so obnoxious that any one who is acquainted with the
balsam instantly recognises its peculiar unpleasant
odor corrupted by the urinary and alvine excretions.

But we have yet to take notice of the greatest
modifications to which this secretion is subject, those
that are symptomatic of or consequent upon certain
diseases. Some of these variations were particularly
made the subject of observation by the ancients, and
have in former days furnished etnpirics with tests of
a very imposing nature of their pretended superior skill
in curing many internal disorders ; the same have also
served to weave a cloak of ignorance and deception for
our farrier*; in which they seldom fail to wind up their
accounts to the satisfaction of their confiding employ-
ers : on the other hand, modern veterinarians in re-
jecting the popular notions of their predecessors of
seeking for the cause or nature of the disease in the
appearaiice of the urine, seem so completely to have
laid aside the practice that they leave themselves un-
acquainted with what few morbid alterations the urine
really does undergo. We know in the human subject
that what is called the lateritiom sediment denotes the
decline of acute disease ; that the urine is colorless in
hysterical affections ; that it is deficient in its earthy
ingredient pending gout, but abounds in that substance
where there exists mollities ossium : but I know of no
such connected observations in veterinary pathology.
In diabetes the urine of horses, as well as that of men,
may be boiled down to a saccharine matter resembling
molasses or treacle. Occasionally we meet with bloody
urine : this may proceed either from excess of vascular
action, or from injury to the glandular substance or

On the Physiology of the Urinary Organs. 23

any of the mucous suifacfts over which the urine lias
to pass ; and in cases where these passages throw off
more than ordinary secretion or run into suppuration,
mucus or pus will be found mixed with the urinary
discharges.

Having submitted these leading facts in regard to
the process itself, and the variations that have been
noticed in the quantity and quahty of the fluid secreted,
we now come to the consideration of the grand ques-
tion, for what specific design in the animal economy such
a secretion was instituted. Considering the aqueous
constituent of the blood as the material by which the
temperature of the system is kept down by evaporation
from the surface of the body, the kidneys have been
viewed as parts performing a subordinate function to
the skin, simply as a secondary or minor part of the
cooling apparatus. The theory, and a very rational
one it is, is this. The animal requires a certain quan-
tity of perspirable fluid in the blood for the purpose of
conducting heat from the surface during exercise, hot
weather, or any other influence that may raise to, excess
the temperature of the body ; but as this fluid is
sensibly perspired only on such occasions, there re-
quired an emunctory to get rid of it when it is not
wanted for this purpose, which emunctory is the kid-
neys. Moreover, it is urged in favour of this very
plausible theory that this explains why the urinary
secretion is not required in the foetus ; namely, be-
cause the surface of its body is .surrounded by fluid,
and a fluid invariably of the same temperature. For
my part, I look upon this as I do upon that opinion
which ascribes the office of the spleen to be to prepare
blood for the liver : I do not see in any other instances
that such complicated and expensive means are pro-

24 On the Phi/siologi/ of the Vriuary Organs.

vided solely to bring about such comparatively simple
ends, and I feel more disposed to dissent in the pre-
sent case because another office, and in my opinion one
infinitely more consistent with the indisputable im-
portance of the organs, has been assigned to them. Is
it in accordance with the other operations of the animal
economy to set down such a complete organic structure
with all its appendages as nothing but a waste-but to
the skin, a part with which in structure it will admit
of no analogy whatever, and between whose secretions
there is just as little affinity ? Is it likely that two or-
gans should have been so intricately constructed and
organized and placed where they are purely for the pur-
pose of acting in subserviency to a part of such compa-
rative unimportance and simplicity of structure as the
common covering of the body ? I should unhesitatingly
answer. No ! and rather say, with others, though their
assumption may be one that does not directly admit of
proof, that the principal use of the kidneys is to sepa-
rate certain matters from the blood, under the form of
urine, which have become excrementitious either from
having served their ends and become Vv^orn out, or from
their retention in the system being actually prejudicial.
We know that there is a continual change of material
going on throughout the body, that every part becomes
renewed within a certain space of time, and that cer-
tain parts that grow useless become absorbed and car-
ried into the system along with the old materials : con-
sequently there required, not merely a discharging
channel, but an organ having the power to select these
materials out of the circulating mass and elaborate them
into a form convenient for expulsion. But does the
urine afford any evidence of such a material ? Yes ! it
yields a substance named urea, which exceeds in quan-

On the Physiologif of the Urmary Organs* 25

tity all the other substances contained in it, to which
its color, odor, and every other characteristic property it
possesses is found to be attributable ; and this urea we
imagine to be the said excrementitious material so
changed that it may be dissolved in water and with-
out difficulty discharged through the urinary passages :
at the same time this water in the blood, which serves to
hold the urea in solution in the form of urine, is as oc-
casion may require at the disposal of the skin. So far
then I am ready to admit that the kidneys are connected
in function with the skin ; only let it be remember-
ed that this is secondary to the important part they
perform in tlieir rank of complicated glandular struc-
tures.

Healthy urine, as every one knows, is a fluid of an
amber color, of a sharp saline flavor, and of a peculiar,
pungent, offensive odor ; but its color, flavor, and odor
will vary with the circumstances already mentioned
which influence its secretion. Besides urea, of which
the lateritious sediment principally consists, it contains
albumen, commonly some mucus, and different salts ;
all which, in extremely variable proportions, are held
in solution in an equally variable quantity of w^ater.
According to M. Girard, the salts found to predomi-
nate in the urine of the horse and ox are, carbonate of
lime and soda, muriate of potash and soda, and ben-
zoate of soda.

The Bladder, though not absolutely a necessary,
is a very useful part of the urinary apparatus. The
secretion of urine being incessant and its transmission
through the ureters uninterrupted, if there had been
no bladder the urine must have been continually drib-
bing from the animal, thereby keeping up a constant

26 Oti the Phi/sioiugi/ of the Urinary Organs.

fetor, irritation, and excoriation, besides other annoy-
ances, all which may be better conceived than describ-
ed : malformations of this description are on the records
of human medicine ; but I have never met with any
such accounts relating to the brute creation. The
urine then as fast as it collects in the pelves of the
kidneys from the terminations of the infundibula, is
received by the funnel-shaped mouths of the ureters,
conducted by those tubes into the bladder, and therein
deposited by each of them drop by drop. As it con-
tinues to receive this guttatim influx of urine, the
bladder insensibly increases in volume ; its sides sepa-
rate and dilate, the rugse vanish from its interior, and
the parietes of the bag grow thinner and thinner until
they become stretched and attenuated even to a degree
of transparency : this dilatation in the longitudinal dia-
meter is equal to double what it is from side to side
notwithstanding the former only takes place in one
direction ; for the cervix of the bladder being a fixed
point will not admit of elongation, whereas the fundus
being only loosely attached keeps gradually rearing
itself forward, passes the pubes, and protrudes into the
cavity of the abdomen. Urine that has once entered
the bladder cannot possibly return : the oblique insi-
nuation of the ureter between the fibrous and inner
tunics forms so effectual a valve that even air cannot
escape it, and what adds to the beauty and effect
of this valvular contrivance, is, that the obstacle is
strengthened in the same ratio in which the resistence
caused by distention is increased. Whenever a cer-
tain quantity of urine is collected in the bladder a
sense of uneasiness is created which the animal well
knows is the warning to stale : if he does not obey this

On the Physiologi/ of the Urinary Organs. 27

inward call, and particularly if his attention be diverted
at the time by some unexpected incident, the feeling
will die away and the interval of retention be pro-
tracted ; but this remission of the act, althouo;h it
admits of considerable latitude to suit the convenience
of the animal, cannot be prolonged beyond a certain
limit without inducing an irresistible impulse to yield
to the efforts of nature. This desire to empty the
bladder will not be regulated solely by the degree to
which the organ may be distended ; it will be consider-
ably influenced by the habits the animal may have
acquired of staling at longer or shorter intervals. It
is therefore by a voluntary power that we expel urine
from the bladder ; in a state of health no involuntary
discharge ever takes place ; and the act is performed
in this manner : —

The animal (supposing him to be in action) first
stops and places himself in a certain convenient posi-
tion ; he then takes in a deep inspiration, by which
the diaphragm thrusts the abdominal viscera towards
the pelvis and keeps them pressing upon the bladder ;
lastly, still holding his breath, by the exertion of the
abdominal muscles (particularly the transversales) this
pressure is greatly increased, and by the joint-contrac-
tion of the muscular coat of the organ itself is rendered
available in its evacuation. It would appear from
what we have learnt by experiment and from patho-
logy, that these powers acting singly are insufficient to
the end : if the bladder be paralysed all voluntary
efforts to discharge the urine are unavailing, and so
are the contractions of the organ itself when the abdo-
minal parietes are cut away. During the continuance
of the act the impetus of the stream may be increased

28 On the Physiology of the Urinary OrgaihS.

at pleasure, or the cun-ent may be projected by jerks
as it commonly is towards the conclusion : the former
is the effect simply of increased abdominal effort, the
latter is ascribable to the superadded action of the acce-
lerator urinae. But a few drops make their appearance
or the stream is but small at first in consequence of
the time taken up by the voluntary powers in over-
coming the opposition at the cervix of the bladder ;
but, when once this part is dilated the urine flows in
full stream and continues so to do without further
effort, as is seen by the relaxation of the flanks and
the recommencement of respiration, the operation being
continued by the bladder alone. Towards the end of
the act the stream becomes again diminished, and the
last portions of urine are so feebly expelled from the
bladder that their discharge from the urethra calls forth
the contractions of the accelerator urinae. Throuo-h this
same muscle also the animal has the power of sud-
denly arresting or interrupting the stream during
micturition, and of resisting an urgent impulse to stale ;
for it will so effectually compress the urethra all the
way from the bulb to its termination that no effort the
bladder can make can have any effect.

Whatever may be the amount of the contractile
powers of the bladder they are to be considered as
altogether without the pale of voluntary influence ;
there is an inherent or natural tendency in the organ
to contract, as is plainly proved by leaving a catheter
in it, and in cases in which there exists paralysis of its
neck. We can understand how the urine is discharged
from this organ by certain auxiliary forces, and how it
is retained or the stream at pleasure arrested by similar
means ; but it does not appear so easy to demonstrate

Qn the Phi/siologi/ of the Urinary/ Organs. 29

the contrivance whereby the urine is kept from flowing
spontaneously, without admitting (what we have not
been able to develop to our satisfaction by the knife)
the existence of a sphincter vesica : if the part really
does possess this faculty and is the sole and efficient
cause of the retention, I would rather refer its power to
the smallness of the neck and to its beino; made a fixed
])oint, -circumstances which must materially favor its
action, than to any superaddition of muscle which does
not admit of satisfactory demonstration. That it is
no voluntary effort is proved by its unceasing con-
striction during sleep ; that it is not attributable to
elasticity is proved by its relaxation after death ; that
it is a muscular act is vastly more feasible in a
physiological than an anatomical point of view ; be
it what it may however we mus^ acknowledge Its con-
tractility or we cannot account for the closure of the
bladder.

Finding that the urine voided at different intervals
is dissimilar in its properties, physiologists in general
believe 4hat it undergoes some alterations during its
stay in the bladder ; I do not apprehend however that
this is a change of any specific nature, but purely one
referable to the circumstances under which it is therein
lodged. The urina potus indeed appears to pass
through the cavity the same in composition as it was
when received from the kidneys ; but that which is
slowly secreted and is long retained in the bladder,
becomes turbid, acquires a peculiar smell, and is found
to be charged with animal matter : properties (as far
as relates to the bladder) ascribable to some absorption
probably of its aqueous parts, and the admixture of
the secretions from its internal surface.

LECTURE LV.

I SHALL commence this lecture with a few observa-
tions on

Diuresis and Diuretic Medicine.

By diuresis is meant discharges of urine recognised
to be inordinate in quantity and in the frequency of
their return : diuretics are the substances which pro-
mote these discharges. The secretion of urine may be
augmented in two ways ; either by producing an actual
augmentation of that (the aqueous) constituent of the
blood from which the bulk of urine is obtained, or by
introducing a substance into the system which will
turn out to prove a direct stimulus to the kidneys
themselves. I observed in the former lecture that
liquids passed out of the system in three ways, by
cutaneous perspiration, by pulmonary exhalation, and
by urine ; and that augmented drinking was commonly
followed, as a natural consequence, by augmented
urinary discharges, a fact that has given rise to a
common practical observation, " that water is the best
diuretic ; " this however, it will be seen, can only
hold true in a conditional sense, for if the cutaneous
or even the pulmonary surface happen to have the

3

Diuresis and Diuretic Medicine. 31

determination of blood in its favor, the kidneys may
make no more than the ordinary quantity of secretion
though the imbibition have; been considerably more
than usual. This is but rarely the case however in
horses. Man, we know, in warm weather throws off
the largest proportion of fluid by the skin and thus
wards off the heat from his naked surface : animals
having hair dispose of their fluids principally through
the other channels ; the dog cools himself by pul-
monary exhalation ; the horse, who rarely perspires
but under exertion or pain, has probably of all other
animals the most susceptible kidneys.

Substances that promote the secretion of urine may
be either of an alimentary or a medicinal nature.
Mow-burnt hay, foxy oats, and all sorts of high-dried
and fermented provender prove more or less diuretic to
horses unhabituated to such food ; and in a general
way this forms one objection to their use, for nothing
tends to debilitate a horse more than frequent and
long-continued excitation of the kidneys. Diuretic
medicines are both great in number and various in
kind, but they require on our part the exercise of more
precaution in the exhibition of them generally than judg-
ment in the individual selection of them : this is not the
case in the human subject, but it is a practical point
to be minded by the veterinary surgeon if he would
eschew those evils into which the farrier, the horse-
man and his groom, are every day the unknowing
authors of. The neutral salts, particularly nitre ; the
alkalies, uncombined or as they exist in soap ; the
balsams, especially that of copaiba ; the terebinthates
in a remarkable degree ; lytta in a violent degree ;
savin, oxy-muriate of mercury, nitrous oether, and

32 Diuresis and Diuretic Medicine.

some others, all possess diuretic properties ; in ordinary
practice however we seldom use any others but soft
or hard soap, yellow resiij, and common turpentine*'.
The prompt action of diuretics and the debility of
system they have a tendency to induce (though that
is an effect that can only be insured at the expense
of violent derangement if not progressive disorganiza-
tion of the secretory structure of the kidneys) have
led to their use in cases of plethora, and in febrile and
pulmonary affections ; but they are chiefly employed
in dropsies of all kinds. If a horse is brought to us
purely for having anasarcous legs we prescribe for him
a course of what we call diuretic medicine, and w^e
know for certain that his legs in the course of a few
days will become fine. Now, what is the theory of
this ? Is it to be explained by saying that the kidneys
are stimulated by the medicine to secrete more than
the ordinary quantity of urine, and that the absorbents,
as a natural consequence, set to work to make up for
this inordinate abstraction of the watery parts of the
blood by taking up that deposited in the legs ; or is
it that this medicine, which we call diuretic, stimulates
the absorbents, and that the increased action of the
kidneys is ascribable to the augmented influx of lym-
phatic fluid into the circulating medium ? A know-

* R Saponis duri vel mollis 3ij.
Resin. Flav. Pulv. 3ft.
01. carui 3i. m.

Ft. Bol. omni nocte exliibendus.
R Terebinth. Vulg.
01. Juniperi 5i.
Pulv. GlycyrrhizcE q. s.
M. ft. Bol. alternis diebus dandus.

Diseases of the Vnnuri/ Organs. 33

ledge of the bare fact will serve us for every purpose
of practice ; and therefore I shall not take up this
lecture by launching into any theoretical solution of
it ; but proceed forthwith to the

Diseases of the Urinary Orgatis.

The general abuse of diuretic medicine, coupled with
the known susceptibility of the organ itself, renders
the kidney the seat of frequent disordered function, and
every now and then of violent and destructive disease.
The disordered function is probably the result of
increased action, which may or may not amount to
inflammation ; if it do not in the first instance the
frequent repetition of the stimulus does not fail to
give rise to it, most likely in the chronic form, and
this languid inflammation, which within certain limits
would still die away on a total discontinuance of the ex-
citing cause, aggravated from time to time by the same
injurious diuretic influence, becomes at length esta-
blished, and then never leaves the part until it has
even defeated its own progress by inducing disorganiza-
tion, induration, schirrus, ulceration, and suppuration,
&c. : this is a subject however on which we are in the ex-
isting state of veterinary medicine wofuUy uninformed,
and therefore we must content ourselves for the present
with a knowledge of the more tangible form of renal
disease.

Nephy-itis.

Acute injiantniation of the kidney ox kidneys I believe
to be uncommon, viewed as a spontaneous affection ; by
which I mean, a disease arising without any apparent
or assignable cause : its origin may generally be re-

PART 111. D

34 Nephritis.

terred either to excitement of the organ, or to some
sprain or other injury about the loins ; a prudent
practitioner therefore will not fail in cases of this
nature to inform himself of the circumstances under
which the disease has made its appearance, and he
will find that this knowledge will contribute vastly to
lighten him on the road of subsequent investigation.
The ordinary symptoms are— The horse stands wide
and stiffly with his hind legs. In walking he shows an
awkward straddling gait behind : this is more remark-
able when he turns round or is put into a trot, actions
he manifests unwillingness to perform. He probably
expresses tenderness in the neighbourhood of the kid-
neys by shrinking from pressure upon the loins. The
urinary discharges are suppressed altogether ; or, should
any make their appearance, they are frequent, sparing,
high-colored or bloody, or perhaps mingled with pus :
all which will depend on the stage and violence of the
inflammation. The bladder is empty. The system is
suffiering from more or less febrile disorder. Tha pulse
is small and very quick.

The common causes are : the frequent use of acrid
diuretics, feeding with certain kinds of diuretic pro-
vender, or even the long continuance of certain mineral
waters ; overweighting, leaping, suddenly turning or
pulling up upon the haunches during the gallop or
fast trot, by which the loins are sprained or otherwise
injured ; lastly, the irritation excited by calculous
matters within the pelvis.

The diagnosis, being a point of great importance in
the treatment, ought to be carefully made out before
we take any decisive therapeutic measures. We are
most likely to confound nephritis with cystitis : here

Nephritis. 3.3

th e particulars of the history of the case may do mucli
for us ; then we must advert to the peculiarity of
posture and gait, and the total suppression of urine or
state almost equivalent thereto. Sliould there be con-
striction at the neck of the bladder, in which case also
no urine will be discharged, that viscus will be found
on examination prodigiously distended. I know of no
sign that will lead us with any degree of certainty to
infer whether one or both kidneys be affected ; or, if
but one, which of them : and it is of no great import
further than, in the case of but one being affected, the
circumstance will tend to puzzle us in our diagnosis.

I believe the most common termination of cystitis
to be suppuration, not of the cortical part but of the
mucous passages, the infundibula, pelvis, and perhaps
the ureter ; though it may end in abscess of the
entire gland. Condensation, induration, and schirro-
sity of the glandular structure I havo seen specimens
of in the state of preparation. I have heard of
gangrenous and mortified kidneys, but I never saw
• one.

The indications in the treatment are, to subdue the
feverish excitement in the system, and to combat as
closely as we can with the inflammation in the gland
itself by remedies particularly directed thereunto, and
by withdrawing every thing that might have a ten-
dency to aggravate or continue it. Free use ought to
be early made of the lancet ; from four to eight quarts
of blood may be drawn. And that being done, we
are to lose no time in administering a full dose of
purgative medicine : during the interim that this re-
mains inactive we may (after the scybala have been
removed from the rectum) inject at short intervals

D 2

0

36 Diabetes.

copious clysters, wanner than we are in the habit of
using, which will have some beneficial effect as an
internal fomentation and will probably accelerate the
action of the purge. Hellebore will also be found
serviceable in this interim, repeated every four or six
hours until we have induced nausea, a very desirable '
state in this disease. The pulse having been weakened
by the use of the lancet and diminished by the exhibi-
tion of hellebore, we may safely commence counter-
irritation. The common notion that blisters " do
more harm than good" appears to be founded in error ;
for it has been (I may say I believe) proved that
vesication precedes absorption ; if, therefore, a blister
be washed off as soon as it begins to rise we derive all
the benefit without any of the ill effect that the absorp-
tion of lytta (which is an acrid diuretic) would be
productive of. But, if this be questioned, the mustard
embrocation may be spread upon the loins instead of
the blister. The more diluent fluid taken (barley
water, oatmeal gruel, linseed tea, or even plain water)
the better; but I would not drench the horse with
any : at the same time we should take care to get rid of
as much of this fluid by the skin as possible by warm
clothing ; though it pass off by urine however (which
most of it probably will when the inflammation is on
the decline) it will still prove beneficial by diluting the
salts and thereby diminishing the acrimony of the se-
cretion. Scrupulous abstinence should be enjoined from
the use of any food or water having diuretic properties.

Diabetes.

This is commonly classed among renal disorders,
inasmuch as the urine is found to possess a particular

Diabetes.

37

sweet taste or saccharine quality, and to be voided
not only in unnatural profusion but at more frequent
intervals than in health. Though diabetes is an in-
frequent malady among horses we cannot make a plea
of this circumstance for passing it over in silence : no
one can tell how soon he may be called to treat a case
of disease of rare occurrence, and if then he feel him-
self unprepared, though he may administer placebos to
his employer, it is rather vexatious to have afterwards
to reflect that his unfortunate patient, brute as he is,
might have been saved had he fallen into other hands.
Though the saccharine property of the urine and pro-
fuse staling are the circumstances upon which we must
rely to lead us to the detection of diabetes, it appears
that neither of these symptoms singly is essential to its
existence ; for, in the human subject the secretion has
been known to be saccharine and yet remain unincreas-
ed, and to be augmented but inodorous and destitute of
saccharine matter, a form of the disorder that has
been distinguished from diabetes meUitus by the epithet
insipidus: I am not certain however whether we are
warranted or not in makino- a like distinction, and so
I shall collect what information I can about the first
of these disorders.

The urine is discharged so often and in such immode-
rate quantities that it has been known in the human sub-
ject to exceed in weight the ingesta (solid and fluid) al-
together; and Dr. Rollo, who has given an account of
such cases *, detected a daily loss in the weight of these
patients : indeed, some such notion seems to have been
entertained by those who named the complaint diabetes.

* In his work—" Cases of the Diabetes MeUitus"

38

Diabetes.

Thirty-six pints of urine it is said have been voided in
one day by a diabetic man ; I am not in possession of
any similar particulars in regard to horses. The urine
itself is limpid, light-amber-colored, pecuharly odorous,
sweet in taste, and yields, by a process of evaporation,
a saccharine matter possessing properties very similar to
treacle or molasses. These alterations in the quantity
and quality of the urine are accompanied with other
symptoms, which, should those signs escape our no-
tice, (or that of the groom rather) are very likely to
call our attention to the presence of the malady : these
are, remarkable voracity of appetite, intense thirst,
tardy febrile action, dryness and roughness of coat,
falling-ofF in condition, and dullness and unwillingness
to move, followed by general emaciation, extreme debi-
lity, and even death. Its attack is imperceptible, its
progress slow and commonly for some weeks continues
unobserved, for the animal may have the malady for a
considerable time without shewing any very evident
signs of its existence. I do not know that any analysis
has been made of the urine of diabetic horses ; but Drs.
Black and Rollo have found thatjift. of saccharine
matter was afforded by a pint of that voided by a di-
abetic man ; whereas, a pint of ass' milk yielded but
3ft. and the same measure of cow's milk only half that
quantity.

To enter into the theory of this disorder in detail
would take up too much of the present lecture ; I shall
thereibre confine myself to one or two current observa-
tions. These urinary phenomena by some physicians are
regarded as the result of morbid action of the kidneys,
or of an inflammation in them of an indolent or specific
character, ascribing to the organs a power of cenvertino

Diabetes

39

certain parts of the blood into saccharine secretion,
the same as the mammEe appear to do ; the answer com-
monly given to which hypothesis is, that if the kid-
neys can assume the operation of one gland, why not
of another, and secrete bile and semen, &c. The
opinion more generally entertained at the present day
is, that this saccharine secretion has its origin in some
defect in the digestive or assimilatory process ; and this
opinion is supported by the facts— that sugar is one of
the principal and earliest products of digestion and that
chyle is known to contain a considerable proportion of
it; that the vegetable nature of diabetic urine is
proved by its turning acidulous instead of running into
putrescency as common urine does, and by its being
fermentable with and sometimes without yeast; that
a peculiar stomach-affection usually precedes and ac-
companies diabetes ; that an animal diet or abstinence
from all vegetable and sugar-yielding substances will
speedily remove the characteristic symptoms ; and that
dissection has not developed any morbid alteration in
the kidney but what may be referred to simply in-
creased glandular action, viz. some enlargement of the
gland, especially of the uriniferous portion of it.

The exciting causes of diabetes it appears we know
but little about. If it can be proved to originate in
deranged function of the stomach or other of the chylo-
poietic organs, we must look for the cause either in the
nature, quality, &c. of the provender, or in some kind
or other of organic dyspeptic affection. On the other
hand, if it be viewed as a renal disorder we must search
among those causes that operate more particularly on
the kidneys. It has been attributed to over-work, di-
uretics,- &c. but without any apparent or receivable
reason.

40 Diabetes.

To the surgeon I can imagine the treatment of a case
of diabetes to be an affair of some degree of perplexity ;
wavering as his mind probably is about the uncertainty
of its seat and nature, and having before him the ani-
mal diet system of Dr. Rollo, and the antispasmodic,
tonic, astringent, and antiphlogistic plans of other ac-
credited physicians, he has nought to resort to but the
result of his own experience, or, if that be too limited,
those impressions which his mind may have received
from the public or private practice of another. This is
a dilemma from which the veterinary surgeon however
is in part relieved : animal diet he cannot for obvious
reasons have recourse to ; indeed, I do not think my-
self that he can to much advantage diet the animal at
all ; his views therefore may be exclusively directed to
medical treatment. Ammonia may be made trial of, on
the principle of its being one of the principal compo-
nents of animal matter ; sulphur and the sulphurets,
as having a similar influence and being aperient ; alka-
lies, calcareous and testaceous substances, to correct
acidity ; oak bark and forge water as tonics ; &c. &c.
but, for my own part, I would rather proceed on the
antiphlogistic plan. I would bleed, but not largely, if
the pulse indicated increased action, and repeat the ope-
ration if any benefit seemed to result from it. I would
give mild purges, and in the intervals perhaps hydra-
gyrus c creta. I would also institute counter-irritation
upon the loins ; if not by blisters, by the mustard em-
brocation or some stimulating ointment that possesses
no diuretic ingredient.

The diseases of the bladder may be com-
prehended under the heads of cystitis, paralysis, and
calculus.

41

Cystitis.

Injlammation of the bladder may attack the peritoneal,
muscular, or mucous coat, or it may confine its action
to the neck. I know nothing about the first of these
affections but as a concomitant or extension of perito-
nitis ; in which case, in addition to the regular set of
symptoms, there will be shown to be present irritability
of the bladder, by frequent small discharges of urine :
this however will require no material variation in the
remedial measures. And I cannot discover any im-
portant therapeutical advantage to be derived from
drawing a line of distinction, even admitting it to be at
all times practicable, between inflammation of the mus-
cular and mucous coats ; I shall therefore proceed to
treat of these affections together.

The prominent symptom of either of these forms of
cystitis will be frequent and painful efforts to stale, in
which the animal will void his urine in very small
quantities ; for, observe, the irritability of the bladder
may be exalted from two causes, either from an in-
creased excitability to action in the muscular coat, or
from the irritation to which the mucous coat is exposed
from the cessation or alteration of its secretion ; and
both these causes have their foundation in inflammation.
Febrile symptoms will keep pace with the virulence of
the disease going on in the bladder. Without advert-
ing to other affections, renal as well as vesical, how-
ever, this solitary local symptom will not bear us out
in our diagnosis. The supposed disease in question
may be nephritis ; though we may suppress our suspi-
cions on this head providing there be, in the aggregate,
much urine voided, and that urine unaltered in quality ;

42 Cystitis.

and providing the peculiarity of posture and gait and
the tenderness about the loins be absent. Inflamma-
tion of the neck may also give rise to the same symp-
tom; but from this it may at once be discriminated by
ascertaining whether the bladder is full or empty : this
may be done by an experienced hand by pressure be-
fore the pubes, but the more certain mode is examina-
tion per rectum.

This is rarely a spontaneous affection. Almost always
we may detect some local cause of irritation, such as
calculous matter or some other irritant in the urine.
Professor Coleman relates in his lectures the cases
of two mares that were the property of Gen. Brown-
rig, in whom the mucous coat of the bladder was in-
tensely inflamed, in one indeed mortified, with ero-
sions through the viscus, in consequence of the introduc-
tion of some acrid caustic substance by the coachman,
who, it appeared, w^as extremely desirous that the mares
should go to horse : the death of one prior to the arrival
of the Professor threw light on the nature of the other's
sufferings ; and she was recovered by active depletion
and the copious injection of warm water into the bladder.

The treatment consists in taking away from four to
six or eight quarts of blood ; in administering from
eight to ten drams of aloes ; in promoting diaphoresis
to the utmost of our power ; in affording an abundant
supply of plain water or some mucilaginous drink ; in
giving one or other of the alkalies to soften the urine ;
in instituting irritation before the pubes, but not by
blisters, unless they be carefully washed off as soon as
vesication takes place ; in the frequent administration
of enemse until purging has begun ; and, in the female.

Cystitis. 43

in injecting from time to time some soothing, mucila-
ginous, alkaline fluid into the bladder.

Inflammation of the neck of the bladder
will give rise to the same frequent and painful strains
to stale as denote the last affection, and these efforts
may also from time to time be productive of sparing
discharges of urine ; for it often happens that a little
fluid will make its escape from the bladder in this
state of preter-natural distention. This throws a cloud
of obscurity over such cases in horses which, as is
justly observed by Professor Coleman, the surgeon
has seldom to cross his way ; for the case of a man
having this disease admits of solution in a great
measure by ascertaining the space of time since he last
voided his urine, whereas in the instance of the horse
this is a piece of information we can seldom obtain,
or, if given, rarely place dependance on the report.
In fact, as a general rule of practice, in all vesical
affections we ought early to ascertain per rectum the
state of the bladder, and not trust to this or to that
account, or even, to the neglect of this indispensable
duty, to the symptoms themselves however well-marked
and decisive they may appear to be.

It seems that we are quite in the dark about the
origin of this disease. It has been referred to spasm.
All that we appear to know about it, is, that it is an
affection that creates expressions of great suffering ;
but fortunately one of infrequent occurrence.

The first step to be taken, and that without delay, is
to reheve the distended bladder, or the consequence
may be its disruption. We are told we must pass the
catheter. Most unquestionably this is a very desirable
measure and would turn out to be a very effectual one

44 Cystitis.

should it prove to be practicable ; but this I apprehend
it will not be found to be in every case. What is to
be done then ? The bladder must be tapped. Now
there are two ways of proceeding in this operation :
one consists in carrying a trocar into the rectum and
plunging it through the gut into the prominent bladder
below ; the other in thrusting the trocar through the
recti muscles immediately in front of the pubes, where-
by the bladder will be penetrated behind its peritoneal
covering, and consequently the abdominal cavity left
uninjured. Considering the horizontal position of the
animal, and knowing the comparative facility with
which these operations are performable, there exists no
question in my mind which ought to be preferred ;
indeed, I doubt (for I never ventured upon the high
operation) that the urine would be expelled throuo-h
the rectum ; whereas the dependance of the opening
made in the front of the pubes singularly favors its
discharge. Having once introduced the trocar I would
endeavour to confine it there by a contrivance of tapes
and rollers until I could succeed in passing the cathe-
ter. In the mean time, the same remedies as are
recommended for the other forms of cystitis ought to be
put in practice in this.

Passing the catheter in the male subject is
not the same simple operation in a horse that it is in
a man. In the latter, an inflexible instrument havino-
a certain curve may with facility by a skilful surgeon
be passed down the penis through the urethra into the
bladder : not so in horses, in whom the urethra of the
male makes two such sharp and sudden flexures under
the ischial arch that all such attempts must prove
abortive. To surmount this obstacle the way in which

2

Calculus. 45

we proceed, is this— We first pass a whalebone or
common bougie as far as the ischial arch, at which
place its extremity may readily be felt in the perineum ;
we then make an incision, guided by the end of the
bougie, so as to lay open the urethra to the extent of
three-fourths of an inch ; through which artificial open-
ing we introduce a female catheter and easily push it
onward (the canal from that part being horizontal)
into the bladder.

I have nothing to offer about paralysis of the
BLADDER ; indeed, I know nothing of its existence but
as an occasional consequence of disease or injury of
the spine, to which part in course our attention must
be directed to afford permanent relief.

Calculus *.

U RiNARY calculi, rather an infrequent formation
in horses, are mostly found lodged within the pelves of

* Mr. Sewell did me the kindness to call my attention to the
following detail in time for insertion as this Lecture was going
through the press : —

" Wells, Somerset, August 9, 1824.
" The following account of the extraction of a stone from a horse's
bladder has been communicated to me by Mr. W. Mogford, who
was some years ago my pupil and assistant, and is now a respecta-
ble practitioner at North Low, near Oakhampton, Devon. Should
you think it worth the notice of your readers, I will thank you to
insert it in your valuable Journal. I am, &c. James White.

"The horse is the property of James Veal, Esq. near Hather-
leigh, Devon. When taken up to be broke, he was found very res-
tive, kicking off most of those who attempted to ride him : in con-
sequence of this he received very rough usage, and has since been
ridden rather hard. When Mr. Mogford was desired to attend

46

Calculus.

the kidneys : tlie reason of which is, as the Professor
has long told us, the horizontal position of the trunk ;

him, he observed a peculiar stiffness in the movement of the hind
legs, urine of a high colour and pungent smell, and a dribbling of
urine from the penis for some time after staling ; pulse between 70
and 80, and hard. By bleeding freely, clysters, fomenting and
embrocating tlie loins, and a week's rest, he appeared sufficiently
recovered to be sent to grass. He soon leaped over the gate of
the field, and, crossing the country, got back to some pasture where
he had been usually kept. This exertion caused a return of his
complaint, and Mr. M. was again desired to attend him. He
found him in the same state as before described. Wishing to
examine the bladder, he introduced his hand into the rectum for
that purpose, and immediately felt a hard substance, which ap-
peared to him to be a stone in the bladder. He communicated
the circumstance to Mr. Fisher, surgeon, of Hatherleigh, who
could not be persuaded that it was a stone, until he had made the
examination himself, when he also felt it distinctly. Mr. M. then
proceeded to the operation in the following manner : —

" Having drawn out the penis from the sheath or prepuce, he
passed a rod of whalebone up the urethra, until the end of it could
be felt in the perineum. He then cut down upon the end of the
rod, and through the opening thus made in the urethra he intro-
duced a director, and with a probe-pointed bistoury continued the
opening as far as the left side of the anus. He then introduced his
right hand into the rectum, and the two fore-fingers of his left
hand into the bladder, and, without any difficulty, pushed the
stone against the middle finger, by which he guided it to the neck
of the bladder, and then easily forced it out through the opening in
the urethra. The stone weighed rather more than four and a half
ounces. Some parts of the stone appeared to have been broken
off, and left in the bladder : these were easily removed by means of
a bit of soft sponge tied to a whalebone probe, and some warm
water. The wound quickly healed, except a small orifice, through
which a part of the urine still passes ; but the horse has worked
hard since, and suffered no inconvenience from it. INIr. M. has
no doubt that a stone of seven or eight ounces might be thus
extracted."— Med. and Fhy. Journal.

Calculus.

47

did the ureters descend as they do in man there can
be no doubt but that most of the stones would be
found in the bladder; as it is, calculus in the blad-
der is a rare occurrence. La fosse, in his " Dictio-
naire d'Hippiatrique," gives an instance of stone in
the bladder which occasioned pain and trouble in
staling, and frequent urinary discharges ; this led to
an examination per rectum, and the stone was felt,
and afterwards extracted by an operation similar to
the one parctised in human surgery. I have never
had an opportunity of operating myself ; nor am I in
possession of the particulars of any recent operation of
the kind. Many years ago the operation was about to
be undertaken by my father at Woolwich ; but the
horse was suddenly seized with convulsions and died
in the interim of suspense. The stone was found
within the cervix, ulceration had made holes through
the bladder, and two pails-ful of urinous fluid were
measured out of the abdomen which had created
intense inflammation of the peritoneum.

An unobjectionable and ready mode of ascertaining
the presence of stone is, in my opinion, manual exami-
nation per rectum while the animal is thrown upon his
back, this being the position in which the calculus will
in the male impress the gut : in the female, the vagina
is the channel of introduction. Were I however called
to a case of this description I should not proceed by
" cutting for the stone ; " I should give the decided
preference to the operation of dilatation, one that,
it strikes me, with an instrument properly constructed,
is singularly applicable, not only in the female but in
the male subject, to veterinary practice.

LECTURE LVI.

On the Male Organs of Generation.

The male animal, though his part in the business
of procreation appears to be but simple when compared
with the tedious and critical process of generation in
the female, is nevertheless provided with an assemblage
of organs whose individual structures and functions we
may rank among the most complicated in the system.
These organs consist of glandular bodies whose office
it is to prepare the fluid necessary to impregnation —
the testes ; of canals and receptacles to conduct and
contain the prolific fluid — the vasa deferentia and vesi-
cula seminales ; and of an instrument to transmit this
fluid into parts formed to receive and dispose of it in
the female — the penis and its apperte nances.

The Testes.

The two testicles, the truly essential organs of pro-
creation in the male, hang between the thighs within
a bag called the scrotum : a part I shall commence
my description with.

The scrotum or purse consists of a loose produc-
tion of the common integuments, laterally continuous

The Testes.

49

with the skin covering the flanks and thighs, in front
with the sheath of the penis, and behind with tlie
perineum: a term under which may be comprehended
the space between the scrotum and anus. The skin
forming- the scrotum is thin and soft in its texture,
generally black, and is clothed with fine downy
hair, long and bushy around its sides, short, scanty,
and hardly perceptible about its inferior parts. The
prominences of the testicles produce a longitudinal
crease in the middle of the scrotum, named the raphe,
of which a faint trace extends into tlie perineum : this
crease denotes the line of attachment of the septum
scroti. Prior to the appearance of the testicles the
purse is comparatively small and insignificant, con-
sisting merely of some loose folds of skin ; but during
their descent from the belly it becomes gradually
developed, and the wrinkles from extension by degrees
disappear.

On cutting through the integuments of the scrotum
we expose a pale, yellowish, fibrous layer of substance
which is considered to be muscular ; indeed by some
it is described as a distinct muscle and named the
dartos ; by others it is regarded but as a continuation of
the faschia superficialis abdominis. Its fibres, which
run longitudinally, are strongest where they cover the
testes ; they are extended anteriorly into the cellular
substance of the sheath, and posteriorly are continued
upon the root of the penis. This substance loosely
adheres to the skin by cellular membrane, and is still
more loosely connected by similar interposition to the
parts within. It is certainly distinctly fibrous in com-
position, but its fibres possess a density and toughness
and a yellow cast which accord more Avith the pro-

PAET III. E

50 The Testes.

parties of ligament than muscle ; and furthermore, I am
acquainted with no physiological fact that warrants
such an inference, for the scrotum of the horse does
not corrugate from the application of cold or other
stimuli as that of a man is known to do ; we cannot
therefore avail ourselves of the contractile power of
the scrotum, at least not to the same extent as some
human anatomists have done, to strengthen suppositions
of the presence of a dartos. This fibrous layer is most
loose and abundant along the middle of the bag,
where its expansions from either side unite and are
reflected upward in inseparable union with each other
in the space between the testes, forming in this manner
the septum scroti, which consequently extends from the
raphe to the under and posterior part of the penis, and
serves to prevent one testis from encroaching upon or
interfering with the other.

The cellular membrane of the scrotum, which may
be considered as the third layer of substance entering
into its composition, is interposed in the greatest abun-
dance between the fibrous expansion and the peritoneal
coverings of the testicles. Being very long and loose
in its texture, and destitute of any adipose matter, the
parts it connects are extremely moveable upon each
other and admit of considerable extension.

Continued from the faschia superficialis abdominis
upon the spermatic cord, and thence into the fibrous
texture of the scrotum (which, as I remarked before,
has been regarded as a prolongation of it) is a thin,
cellular, and fibrous expansion ; and underneath this
runs a layer of fleshy substance that has, when con-
trasted with the surrounding white parts, a remarkably
red aspect : this is the cremaster muscle. Its

The Testes. 6i

fleshy fasciculi have a tendinous origin from the inter-
nal oblique and transversalis muscles at the internal
ring, whence they pass obliquely backward upon the
cord, are reflected forward and inward with it through
the external ring, and end slantwise in a digitated
margin, just as the cord joins the testicle ; from these
digitations several slender flat tendons descend and
expand upon the inferior surface of the tunica vagi-
nalis, with the substance of which they become so
interlaced that we lose all further trace of them.
These tendons add greatly to the firmness and resist-
ance of the vaginal tunic, rendering it more efficient
as an external covering and protection to the testicle*
The muscle itself aids in the suspension of the testis,
and in action will retract it as high as the ring : it is
more especially called into action at the time of coition
— at the moment probably that semen is passing from
the organ into the urethra. This is a comparatively fee-
ble muscle in the human subject, and is commonly an
involuntary one ; though there are persons that can
draw their testicles up at will. In order to give some
notion of the forcible action possessed by the cremaster
in the horse, I would simply desire those who are in
the practice of castration to reflect on the force required
at the moment that the testicle is graspfed by the hand
to counteract its retraction. When the testes hang
low, and feel Joose and pendulous within the purse,
which is stretched and rendered thin and flaccid by
their weight, it is according to a vulgar notion a sign
of debility : the parts are found in this condition after
the act of coition, and this circumstance probably has
given rise to the above supposition ; and so far reason-
ably enough, for then the cremaaters become relaxed

E 2

52

The Testes.

both from the fatigue consequent upon their long-con-
tinued and forcible contraction, and from a general
sense of debility or dullness which is known after the
act to take temporary possession of the system alto-
gether.

The first or external covering of the testes, one
common to it and the cord, is a borrowed one from the
peritoneum, commonly known as the tunica vaginalis.
The acquisition and reflection of this covering will not
be clearly understood until the descent of the testicle
has been explained ; it may just be observed here, that
it is a continuation of peritoneum formed into a loose
vagina or sheath, which begins at the internal ring,
proceeds with and envelopes the cord, and, lastly, covers
in the same loose manner the testis and epididy-
mis ; so that if the bag be punctured and air or liquid
be impelled into the cavity, the fluid will readily dis-
tend it and mount into the abdomen, inasmuch as
both cavities have a free communication at the inter-
nal ring. The vagina however does not end in single
investment of the testis ; along the superior and
anterior border of the epididymis we find it fixed but
not terminated ; for here it becomes reflected, first
upon the epididymis, then upon the testis, and lastly
upon the cord, so as to give them all a second covering,
which only differs from the first in being everywhere
in close adhesion with the parts it invests : this last
production is called by way of distinction the tunica
reflexa or tunica vaginalis testis ; it must not be for-
gotten however that they are both peritoneal produc-
tions— one and the same continuous membrane. The
vaginal cavity has a smooth polished surface, and this
is" constantly bedewed with a limpid, colorless, serous

The Testes.

53

fluid, which in the operation for castration spirts out
the instant the knife or cautery has penetrated the
tunica vaginalis : it is an accumulation of this fluid
that constitutes hydrocele, a disease that has no exist-
ence, I believe, in the horse abstractedly from abdo-
minal dropsy.

The testes, with their appendages, the epididymes,
constitute the apparatus secretory of the male sperm or
semen : the penis, as I stated before, being simply the
instrument of transmission. We have already seen
that these bodies, though pendulous, are not loose
within the cavity of the scrotum ; we have found them
enclosed in peritoneal tunics, confined by cellular and
fibrous envelopes, and fenced in their respective apart-
ments by the septum scroti.

The general figure of the testis is that of an oval
flattened at the sides ; the magnitude, that of the
egg of a hen : M. Girard says, that the left is
generally a little larger and more pendent than the
right. The testis is suspended within the scrotum by
the spermatic cord ; and in such a position that its
long axis corresponds to that of the body ; it has
therefore anterior and posterior ends; to the latter is
joined the termination of the cord, while the vas defe-
rens departs from the globus major of the epididymis
which is attached by a ligamentous band to the former :
it has also an inferior or convex border, along which are
seen the tortuous windings of the spermatic artery ; a
superior or straight border to which is attached the epi-
didymis ; and two convex sides free and unconnected.

The spermatic cord, the substance through which
the testicle is connected with the cavity of the abdo-
men and by which it is suspended within its scrotal

54 The Testes.

apartment, is composed in the following manner : —
\st. It has four coverings there is immediately under
the skin the faschia superficialis ; next, the cremaster ;
thirdly, the tunica vaginalis ; and lastly, the tunica
vaginalis reflexa : within the cavity formed by the
vaginal tunics it is that the intestine is protruded in
inguinal and scrotal hernise ; the hernial coverings, con-
sequently, exclusive of the sac, are th^ /aschia and the
cremaster muscle. 2ndly. The component parts of
the cord are — a. The arteries which are two in
number : the artery of the cord, a small branch of the
external ihac, which ramifies and expends itself upon
the cord ; and the spermatic artery which, having
arrived at the internal ring, enters the inguinal canal,
runs within the posterior part of the cord, growing
tortuous as it descends, serpentines along the superior
border of the testis, between it and the epididymis,
winds round the anterior end of the gland, and lastly
reaches the convex border where it becomes extremely
convoluted and where its branches are principally dis-
tributed. In its descent it detaches small unimportant
twigs to the adjacent parts ; and as it approaches the
testicle becomes surrounded by an assemblage of
venous vessels, b. The veins, comparatively numerous,
accompany their corVespondent arteries ; the spermatic
veins indeed may be said to make up the principal
bulk of the cord, for they are not only numerous, but
large and flexuous, and as they approach the testis
form a sort of plexus which has got the name of corpus
pampiniforme : these return their blood into the poste-
rior vena cava. c. The nerves, which are derived
from the hypogastric plexus, also accompany the sper-
matic artery ; they are small but sufl&ciently numerous :

The Testes.

56

though the testis does not possess great sensibility in
health, we may vouch for its being acutely sensitive in
a state of disease, d. Absorbents are both large
and numerous in the cord. They are readily found
alongside of the venous trunks ; and not infrequently
may be filled by introducing mercury into the sperma-
tic artery, e. The vas deferens, though commonly
considered as a constituent of the cord, it must be
remarked, takes at first a solitary course, remote from
the blood-vessels ; seeing that it springs from the
summit of the head of the epididymis, which part
surmounts the fore-end of the testicle, in order to go
the nearest way to the cord, its course, which begins
with a series of convolutions gradually unwinding as it
proceeds, becomes necessarily oblique nearly as high as
the external ring, where it joins the blood-vessels, and
continues to accompany them posteriorly through the
inguinal canal ; at the internal ring it leaves them,
turns inward and ascends into the pelvis, where we
find it creeping along the side of the bladder infolded
in peritoneum to get to the cervix, crossing under in
its course first the umbilical artery and then the ure-
ter ; at length it terminates by rather a contracted
orifice within the mouth of the duct of the vesicula
seminalis, just behind a little eminence in the urethra
— the caput galinaginis, about an inch posteriorly to
the cervix of the bladder. Within the inguinal pas-
sage this duct is accompanied by the artery of the vas
deferens, a long slender branch of the epigastric. Its
canal, flexuous until the duct has joined the cord, but
straight in its subsequent course, is not uniform
throughout in calibre ; the area of its tortuous part is
large, but as it becomes straight it grows contracted ;

56 The Testes.

having entered the pelvis it gradually enlarges again,
and acquires unusual volume in running along the
side of the bladder ; and the canal of the enlarged
portion presents a reticulated structure, which gives its
exterior an irregular, tuberculated appearance ; the
most contracted part is that in union with the duct of
the vesicula seminalis, which is a comparatively small
cylindrical conduit. The parietes of this duct are so
remarkably thick and firm to the feel that we distin-
guish it at once by the fingers from the other parts of
the cord : they consist of two tunics ; the external one,
in which its thickness consists, is white, fibrous, and
approaches in appearance to cartilage ; the internal one
is thin and fine in texture, muco-membranous in its
nature, and here and there incloses a reticulated struc-
ture. The different constituent parts of the cord are
connected altogether by cellular substance destitute of
fat ; and from the circumstance of the parts in geheral
being more bulky below the ring the cord increases in
breadth and thickness as it approaches the testicle.

The close or intimate tunic of the testis is perfectly
distinct from its vaginal coats, and from its conspicuous
whiteness is called the tunica albuginea. Though it
may be stripped off in places by the fotceps, and the
separation may be also affected by diffusing quicksilver
into the cellular texture uniting them, the tunica re-
flexa so intimately and uniformly adheres to this
tunic, that, the former being transparent, they appear
to constitute but one and the same covering. The
albuginea however is much denser and firmer in its
nature, and nmch resembles the other fibrous mem-
branes, particularly ttie dura mater, both in appearance
and texture : like that membrane it is extensile and

The Testes.

57

contractile, but neither suddenly nor greatly so, and
imparts a compactness and firmness of feel to the
inclosed structure which the latter, deprived of it, is
not found to possess. Over the convex part of the
gland this tunic is perforated by numerous holes for
the transmission of the spermatic blood-vessels ; inter-
nally it is connected by these vessels to the substance
of the testis, also by a fine cellular web, and by
numerous little processes that traverse the gland per-
pendicularly, serving to hold the internal parts toge-
ther as well as aiding to preserve the form of the whole,
and which are generally described as the septa or sep-
tulce testis.

On cutting^ into the testicle we find that it consists
of a soft pulpy substance of a pale brown color, and
that this by being nipped and drawn out by the forceps
is extensible into numerous whitish threads of extreme
exility which may occasionally be elongated to a consi-
derable degree : it is believed that these are the semi-
niferous tubes. Like other secreting organs, the testis
receives into its composition congeries of arteries, veins,
nerves, and absorbents, the peculiarity of structure
chiefly residing in the arrangement of the secretory
and excretory parts of the apparatus ; it is imagined,
in the instance before us, that this consists in many
vascular coils or complexures which are only separated
from one another by the septulse, and that these, inde-
pendently one of the other, possess the power of secre-
tion. After the spermatic trunk has dispersed its
ramifications over the albuginea, numerous twigs are
transmitted through that tunic into the interior of the
gland : from these, capillary arteries spring, which, it
is presumed, communicate witli the tiibuli semitiiferi.

58 The Testes.

but in what manner anatomists have not been able to
detect ; for in the old subject these tubes are constantly
plugged with secretion and so foil those who make
attempts to inject them, and in the young subject,
before they begin to secrete, they are not sufficiently
developed to admit of the examination. If quicksilver
be suffered to pervade the arteries by its own weight
it is found to return by the veins ; and in a preparation
of the testicle of a dog at present before me the absor-
bents have been filled from the same source. Within
the posterior end of the testis the seminiferous tubes
assemble from the different parts of the interior and
unite into a set of larger tubes of the same description,
which are disposed after the manner of network, and
hence have got the name of the rete ; then, from the
rete proceed another set of similar tubes still larger,
about a dozen, I believe, in number, from the testis to
the epididymis, constituting the sole medium of com-
munication and the principal one of connection between
the two, which are the vasa efferentia. In addition to
these minutiae, we may notice that the superior border
of the testis is marked by a broad white line ; this
denotes the situation of a supposed canal, and is gene-
rally mentioned as the corpus Highmorianum.

The EPIDIDYMIS is extended along the superior bor-
der of the testicle, upon which it rests, and to which it
is connected by the tunica vaginalis reflexa. Its ends
are bulky in comparison to its middle : that receiving
the vasa efferentia, the smaller one, is the caput or glo-
bus minor ; the other, giving rise to the vas diferens, is
the globus major — the part farriers call the nut. The
interior of this appendage to the testicle exhibits a
structure entirely vascular the vasa efferentia unite

The Testes.

59

and re-unite until they form a single duct of whose
numberless and very remarkable convolutions the globus
major is entirely constitued : these tortuosities, which,
when squeezed, freely emit semen, will admit of being-
unwound for a considerable extent so as to have the
length of the duct calculated with very tolerable exact-
ness from beginning to end, which has been found to
amount to several yards. It is small at its formation,
but grows imperceptibly larger in making its endless
windings and turnings until at length it assumes the
size of the vas deferens, in which it ends. Its various
convolutions are connected together by cellular mem-
brane, and are interspersed with a sparing supply of
blood-vessels.

The course of the semen then is this — It is secreted
by the capillary coils of the spermatic artery, from
which it is received by the tubuli seminiferi ; these
tubes convey it into the rete, and the rete discharges it
through the vasa efFerentia into the epididymis, from
which it is conducted by the vas deferens into the ure-
thra.

It is a singular fact, that the organs whose structure
we have been investigating are originally formed in a
situation remote from that in which they are destined
to carry on their functions : " the colt has wo testicles,"
is the common observation of the uninformed on these
matters, and we know ourselves that the purse is without
them, but we also know that they exist ready-formed
within the abdomen, and that they will descend at a
certain period of age into their proper receptacle, the
scrotum. During the fcetal state we find them more
or less developed, tinged with a blush of red, lodged
underneath the psoas muscles, in contact with the in-

60 The Testes.

ferior borders of the kidneys, covered and retained in
their situations by peritoneum, and concealed by the
intestines around them. Here the organ receives its
arteries from the contiguous trunk — the posterior aorta ;
the vas deferens runs forward to meet it ; and the cre-
master likewise turns forward instead of backward :
there being at this time no such thing as a spermatic
cord. Thus placed, the testicle may be regarded as
one of the glands of the abdomen ; indeed, it has con-
siderable similarity to the kidneys in receiving its vessels
from the same contiguous source, and in sending a long
duct backward into the cavity of the pelvis ; and there
does not appear to be any conclusive reason why it
should not perform the same office in that situation
that it does in the scrotum, and particularly since it is
known that in birds they remain and secrete there
during life. From the part where the blood-vessels en-
ter we find growing a whitish substance which is ex-
tended backward, diminishing in breadth as it recedes,
through the ring, where the fibres of the cremaster may
be traced upon it, and whence it is prolonged into the
scrotum, growing still narrower until it vanishes : this
substance, regarded by some simply as a ligament, was
considered by Mr. Hunter, as the guhernaculum or
pilot by means of which the testis is directed in its pas-
sage from the cavity of the abdomen into that of the
scrotum. Quitting the spot where it has been formed
and matured, the testicle gradually retrocedes, guided
by the gubernaculum, until it arrives at the internal
ring, which, at this time (like every other part of the
parietes) is closed by peritoneum ; this temporaiy ob-
struction the testis overcomes by drawing the membrane
with it through the ring and carrying the pouch made

The Testes,

61

thereby down into the scrotum ; the gubernaculum at the
time undergoing a complete inversion. This accounts
then for the production of the tunica vaginaHs, and
explains how that membrane comes to be doubled or
reflected ; for the testis receiving originally (as an abdo-
minal viscus) a close and adherent peritoneal tunic, and
acquiring another, which forms a loose covering, as it
passes through the ring, must necessarily have two ;
and since both are derived from one and the same mem-
brane, it follows that one must be a continuation of the
other. These elongations of membrane, though in
most places in constant contact, are prevented from ad-
hering together by a continual exhalation of their natu-
ral serous secretion ; any interval that may subsist be-
tween them in course communicates with the cavity of
the abdomen through the ring, a part that remains open
through life : this however is not the case with man ; in
his body the communication is cut off, after the testicles
have descended, by a natural contraction and obliter-
ation both of the ring and the inguinal passage. In
many instances one, in some few both, of the testicles
are known to have remained within the belly through
life. As we are unacquainted with the immediate cause
of their descent, so we are unable to give any rational
explanation of this phenomenon. I have understood,
that in many of these cases the glands have been found
to be imperfectly developed : this however is not with-
out exception.

Man and many other animals have their testicles
within the scrotum at the period of birth : in the hu-
man foetus they begin to move about the seventh month ;
about the eighth they reach the groins; and before
birth arrive in the scrotum. But, in the horse, they

62

The. Vesicuia Seminales.

do not pass through the ring until the sixth or seventh
month after birth, and are seldom let completely down
into the scrotum before the expiration of the twelve-
month. In some cases, one testicle will not make its
appearance for a considerable time after the other ; and
as the operation for castration is seldom long delayed
after the first year, this will account for the rigs (as
horses having but one testicle are called) with which
we meet every now and then. Again, instances are
not wanting in which one testicle has descended to the
ring and there remained through life.

The Vesicula Seminales

Are two, oblong, membranous sacs, placed conti-
guously to the terminations of the vasa deferentia,
which have been so denominated from a supposition
that they were receptacles for the semen. They occupy
the lateral intervals left between the bladder and the rec-
tum with their internal prominences, while their exter-
nal are opposed to the sides of the pelvis ; they are
principally sustained in their places by the bladder : in
relation to each other they represent in situ the two
sides of a triangle, for their posterior extremities are
nearly in contact, while their bases diverge as they ad-
vance and leave a considerable breadth of interspace.
The longitudinal channel between the bladder and ve-
sicula is occupied by the vas deferens. The vesicuia
is confined in its situation by cellular connexions with
the bladder and rectum, the walls of the pelvis, and the
vas deferens.

These bodies have a near approach to the pyriform :
anteriorly they present broad round bases which are
elongated posteriorly inta contracted circular necks.

The Vesicul(C Seminales.

63

and the necks end in ducts of some length which may
(to carry the resemblance on) be said to represent the
stalks of the pears ; they incline however to convexity
superiorly and to flatness inferiorly, and their surfaces
are rendered uneven by some tubercular eminences.
The parietes of the vesicula are distinguishable into
two textures. The external one, when cleared of the
enveloping cellular substance, is white, and, though
soft to the feel and not so thick as the outer tunic of the
vas deferens, possesses considerable density and tough-
ness, and in some parts, particularly around the base,
assumes a fibrous texture : these fibres are described as
muscular, and certainly the functions attributed to the
vesiculse appear to demand such a supposition were we
unconvinced of its truth from anatomical inspection,
which, I should say, we are. This tunic is lined with
a membrane, whose surface is of the papillary description
and everywhere presents to view (through a magnifying
glass more plainly) numerous pinhole-like perforations
which are the orifices of subjacent follicles furnishing
the whitish, viscous, jelly-like secretion peculiar to
these bodies. Their ducts are of considerable volume,
not greatly inferior even to the urethra itself : they pro-
ceed backward in a convergent direction in union with
the vasa deferentia, alongside of the membranous part
of the urethra, and terminate behind the verumontanum.

LECTURE LVII.

Penis.

'X HE penis or yard is an organ of large dir^iensions in
the horse species, capable of projection and retraction,
ordinarily concealed within a loose and pendulous dou-
bling of skin at the inferior and posterior part of the
belly. It is not only destined for the important office
of impregnation, and made the seat of that enjoyment
experienced by the male during the copulative act ; but
it serves the subordinate purpose of a convenient con-
duit for the discharge of urine.

The sheath in which the penis is inclosed, and by
which, unless it be in a state towards erection, it is
concealed from view, is nothing more than a prolonga-
tion of the common integuments, having one part with-
drawn within the other and puckered so as to form a
sort of corrugated bag, corresponding to the prepuce
in man, whose dimensions vary with the degree of re-
traction of the peiiis. Posteriorly the sheath is conti- ^
nuous with the scrotum ; anteriorly it is cleft and has
two large pendent folds of skin, proceeding from the
sides of the vagina propria penis, with a broad deep
furrow between them, and extending along the belly as

The Penis. 65

far forward as the navel. In most horses these parts
are dark-colored or black ; in some they are clothed
with fine, long, downy hair ; in others they are infe-
riorly almost bare, having but a few scattered short
hairs which are only perceptible on close inspection.
But there is so much variety in all these particulars
that any single description accurately and minutely
drawn will not apply with precision to another indivi-
dual. Near the borders of reflection of the sides of the
sheath, in the ordinary state of the parts, grow two
small papillee or teats resembling the dugs of the mare ;
they present, in a less perfect degree, the same inter-
nal structure and are perforate at their apices : they are
not to be found however, I believe, in all horses, and it
is the practice of some cutters to take them off at the
time of castration ; Girard observes with truth, that
they are largest in the ass species. Internally, the sheath
— the vagina propria penis, exhibits two large, circular,
tegumental plications : the outer and larger one is formed
by an involution of the external vagina, and exhibits
internally numerous corrugations, which, though by no
means regularly ranged, for the most part run in cir-
cles around the inner plication, the veritable preputium
glandis penis, whose internal surface is also puckered
into circular corrugations, but smaller, and still more
numerous, and more irregularly disposed than those of
the former. These plications are nothing but a conti-
nuation of the common integuments disposed after this
manner to admit of the projection and erection of the
penis, a state in which they, together with their corru-
gations, are extended and annihilated ; the skin com-
posing them however is of a kind remarkable for its

PART III. F

66 The Penis.

fineness and softness of texture, for its black or mar-
bled complexion, and for the excretory pores of myriads
of little subjacent glands which are so closely packed
that it is hardly possible to introduce the point of the
scalpel through it without penetrating one or more of
them. These involutions of skin are supported in their
corrugated form and connected to the body of the
penis by an interposed stratum of cellular substance
which is so loose and abundant as to readily admit of
their sliding over each other, and of the penis being
protracted and retracted with the greatest facility.

From the inner plication the skin is reflected upon
the penis, extending forward and giving a complete
covering to the part named the glans penis. This part
exhibits a veiy remarkable corrugated aspect which I
cannot resemble to any thing so nearly as to the leaf
of a curled cabbage : its cellular substratum is shorter
and more condensed than that of the sheath, it not
being designed to be protracted beyond the penis ; and
like the inner plication it is destitute of those glands
with which the outer is so thickly studded.

The glandules odorifercB are those numberless little
brown follicular bodies that are set in the internal
part of the outer vaginal fold, and discharge a white
caseous matter through their excretory pores upon the
surface. This secretion, which has a peculiar odor, pre-
serves the sensibility of the parts and facilitates their
slipping backward and forward ; it is occasionally found
collected in considerable masses between the outer and
inner plications, even, it has been said, so as to plug
the orifice of the urethra and cause retention of urine :
knowing this, will put us upon our guard, and lead us

The Penis.

to inspect the part in cases where the cause of reten-
tion is not apparent. The surfaces covered by the inner
plication are lubricated by a mucous secretion.

There is yet another involution of the skin. This
takes place at the extremity of the organ, v^^here a lit-
tle cul-de-sac is formed, in the centre of which pro-
trudes the end of the urethra, a part also covered by a
reflexion of this thin, hairless, corrugated integument.
Around the end of the urethra is a little recess partially
divided into two chambers, commonly containing con-
creted masses of a peculiar unctuous secretion : tlie
use of this excavation is not veiy apparent.

The penis inferiorly receives a covering from the fa-
schia superficialis abdominis, lateral portions of which
descend from the flanks and unite along its middle : as
we approach its root the faschia grows stronger, and
exhibits a fibrous texture. The organ derives consider-
able support from this covering.

The penis is constituted of five distinct parts,
which appear to view without the aid of dissection or
disarrangement : viz. the two corpora cavernosa, which
form the middle and sides, the largest proportion of
the organ ; the glatis penis or head, the anterior protu-
berance ; the corpus musculosum urethrce, making up the
inferior portion ; and the plexus venosus, surmounting the
corpora cavernosa. But, before I proceed to describe
these several parts, I shall point out the muscles belong-
ing to the organ.

Erectores penis, a pair of short, thick, fleshy
muscles covering the roots of the penis and the sides
of the perineum. They arise by broad attachments
from the inferior and posterior parts of the tuberosities

F 2

68 The Penis.

oftheischia; mostly fleshy in substance, but blended
with a thin expansion of tendon superiorly, they take
a convergent course, upward and forward, enveloping
the crura penis into which they are extensively inserted.
Their office is to promote the influx of blood into the
organ at the time that it is erecting ; and when in that
state more completely to distend its body by pressing
still more blood into it from the crura.

Triangularis penis is a thin, triangular, fleshy
production, spread upon the upper surfaces of the
small prostrates, extended from them to the large pro-
strate to which it is attached, and surrounding the inter-
mediate or membranous portion of the urethra. Its fi-
bres, which are palish, run across the bottom of the
cavity of the pelvis above the ischial arch from one is-
chium to the other, and have loose attachments to those
bones through the intervention of the cellular substance
in which they are invested. It will contract the mem-
branous part of the urethra in action, and have probably
some effect in discharging fluids from the prostrates.

Accelerator urin;e. This muscle is incorpo-
rated with and may be considered as forming a part of
the penis itself. It springs from the middle and pos-
terior part of the bulb of the urethra, where it is joined
by some scattered fasciculi coming on each side of that
body from the perineum. It takes its course along the
under part of the penis, and may be followed for some
short way upon the glans, forming throughout its ex-
tent a complete fleshy covering to the urethra. It will
aid in the forcible expulsion of the urine; but it is
principally exerted, I imagine, in the ejection of the
semen.

The Penis.

69

The corpora cavernosa penis, the principal
parts in respect to bulk in the constitution of the organ,
parts whose erectile capacity fits it as the instrument of
copulation, extend from the ischial arch to the glans
penis, insinuating their extremities for some little way
under the flattened portion oT the latter. They are at-
tached by means of two branches, the crura penis, to
the posterior ends of the tuberosities of the ischia, and
to the sides of the ischial arch, where they are clothed
by the erectores penis ; from these attachments they con-
verge along the branches of the ischium and under the
summit of the ischial arch form a union. The attach--
ment of the penis to the pelvis is considerably strength-
ened just below this union of the crura by two suspen.
sory ligaments which fasten the sides of the cavernous
bodies to the pubes. These cylindrical bodies, then,
conjoined in one common tunic, continue their passage
forward to the glans penis within the suJjstance of
which they terminate by two rounded protuberances.

The corpora cavernosa are composed of a ligamen-
tous sheath of unusual thickness and toughness, com-
mon to them both, whose fibres, running in every di-
rection, are so interlaced and matted together that it
not only defies our industry, to unravel it, but is even
impenetrable unless when sharp instruments, and they
with no ordinary force, are made use of. It is not every-
where uniform in thickness however : it is compara-
tively thin over the crura and where it is opposed to the
urethra, those parts being sufficiently supported and
protected by their muscular coverings. Their inter-
nal structure, spongy, reticular, or honeycomb-like in
its arrangement, is found to involve three different
textures. First, numberless little tendinous cords,
which are processes from the ligamentous sheath, un-

70 The Penis.

equal in size, run irregularly from one side of the in-
terior to the other : these are crossed in the middle by a
perpendicular set which are broader and stronger, and
so arranged as to resemble the teeth of a comb ; hence
these last, which form the partition between the cor-
pora cavernosa, have been collectively named the pecteti.
Thus, preternatural distention of the organ, and conse-
quent liability to rupture, are guarded against both la-
terally and perpendicularly. Secojidly, the inter-
spaces are filled with a pale-red spongy substance in
which may be distinguished cylindrical processes taking
a longitudinal course : these M. Girard pronounces to
be " evidemment musculaires ;" and I see reason for so
considering them, though I think it is a case in which
we ought to seek confirmation of the fact from physi-
ological or experimental inquiry and not entirely rely
upon anatomical evidence. Thirdly, these cylindrical
bands are surrounded and connected together by a cel-
lular structure that would appear to result from some
peculiar venous arrangement : at least, the small veins,
which are here far more numerous than the arteries,
have everywhere the freest communication with these
apparent cells.

The cavernous structure is especially supplied with
blood by a large vessel, the internal pudic artery, a
branch of the obturator artery, which enters the crus,
giving off several small branches to the other parts of the
organ. The pudic nerves, two in number, springing
from under the ischial arch, are seen entering the cor-
pus at the same place, one before, the other behind the
artery. The internal pudic veins, which are large and
numerous, divide here into two sets, one accompany-
ing the arteries, the other the nerves, after they have
quitted the penis.

Tke Penis.

71

The clans penis is the large, irregular, fungous
protuberance, forming the anterior part of the organ,
which is vulgarly called its head. This part puts on
a very different appearance when distended from the
state in which we find it in the dead animal : it then
presents a broad surface anteriorly surrounded by a
prominent inflected border, which is turned back for
some distance above, but altogether deficient below,
where there is a notch or division of the glans. The
lateral portions are prominent, incorporated supe-
riorly, separate and divergent inferiorly : posteriorly
they are terminated by a contracted circular part,
whose prominent border is the corona glandis. From
the corona extends along the dorsum penis a flattened
substance of an oblong oval figure, which is the poste-
rior or terminating portion of the glans. In the middle
of its anterior surface is a prominence that marks the
termination of the corpora cavernosa ; and below this
is a circular fossa having in its centre the projecting
orifice of the urethra. Altogether, the glans may be
regarded as a part by which the penis is surmounted
to enable the animal to direct the semen with certainty
into the womb of the female, whose inouth is precisely
its counterpart in form.

The internal corrugated production of sheath and
the reflected portion by which the glans is immediately
covered have already been described : underneath this
last we find a fibrous case, of a ligamentary and cellular
texture, holding together the internal structure. The
interior exhibits a honeycomb appearance, is through-
out composed of a soft spongy tissue, in a high degree
distensible and elastic, which some are of opinion is
nothing more than a congeries of veins : whether this

72 The Penis.

be wholly or in part true, venous vessels are found
among the cells, and become large and more conspicu-
ous towards the posterior portion, from which spring
those veins that afterwards so suddenly enlarge and
multiply upon the dorsum penis, forming there that
remarkable, convoluted, venous assemblage, the

Plexus venosus penis. A structure that may
be considered probably as a development of the glans ;
and one that, when distended with blood, in the erect
state of the organ, constitutes no inconsiderable part
of its volume. Though the veins composing it have
free and frequent communication, yet, being furnished
with valves, this communication is not such as will
permit us to fill them with common injection contrary
to the course of the blood : so that when we mean
to distend them with wax we introduce the pipe into
the substance of the glans. Towards the root of the
penis these venous convolutions diminish in number
and volume, and at length end in front of the symphy-
sis pubis in three or four veins of ordinary size, which
are here joined by the epigastric and superficial femoral
veins and then proceed into the pelvis to arrive at the
trunk of the internal iliac vein.

The urethra is a membranous canal extending
from the bladder to the extremity of the penis and
affording a passage for the urine and seminal fluid.
Arising from the neck of the bladder, the urethra, in
its way to the outlet of the pelvis, runs at first horizon-
tally backward with a slight curve downward between
the lobes of the great prostrate, embraced superiorly
by the portio media of that body, and arrives at the
small prostrates, which are situated upon its sides :
this intermediate portion is called the membranom part;

The Penis.

73

incorrectly however, for we find that it is encircled by
some of the fibres of the triangularis penis. Behind
the small prostrates it suddenly bulges or swells in
volume, which part is named the bulb : it is here that
the accelerator urinse begins, the muscle that incloses
the canal during the remainder of its course, and is in
fact a part itself of the urethra. From the bulb the
urethra suddenly curves downward and shortly after
sharply forward, passing under the ischial arch, the
tuberosities bounding it laterally, at which place it is
joined by the crura and subsequently surmounted by
the corpora cavernosa. At the extremity of the organ
it is surrounded by the glans, and terminates in the
centre of the anterior part of that body in a prolapsus
of membrane covered with a reflection of fine skin by
an open orifice which is insulated from the glans by
the fossa running round it. In turning round the
ischial arch the urethra has extensive cellular attach-
ments to the bone ; but it is principally retained at its
curvature by the suspensory ligaments of the penis.
The length of the urethra is nearly two feet, and it is a
canal of considerable dimensions, so that I can with fa-
cility introduce the handle of the scalpel into the orifice,
though that is the smallest part ; for, after it has pass-
ed the bulb, it pretty regularly diminishes in calibre
all the way to the orifice : the canal at the curvature
measuring, when distended with wax, Jour inches in
circumference ; near the orifice, not more than two.

The interior of the canal exhibits a smooth, polished,
lubricated surface, having a pale blush ; in fact, it does
not differ from that of any other mucous membrane,
unless it be that its mucous follicles are larger and
more numerous, whose orifices are here called lacuna.

74

The Penis.

It is continuous, and appears to be one and the same
texture, with the mucous membrane of the bladder.
About an inch and a half from the neck of that viscus,
within the membranous part of the canal, is a little
eminence named the verumontanum or caput galinaginis,
at whose root open the ejaculatory ducts : the use of
this tubercle (which I believe has not been noticed)
appears to me to be, to perform the office of a valve
to the orifices of these ducts, preventing any influx of
the urethral fluids. Upon either side of it are many
small perforations through the membrane : these are
the excretory openings of the ducts of the great pro-
strate. A little in the rear of the verumontanum, are
several, small, papillary eminences, perforated through
their centres, and longitudinally ranged in two distinct
sets : these are the openings through which the ducts
of the lesser prostrates discharge their secretion.

The bulb of the urethra is a longitudinal prominence '
beginning immediately behind the lesser prostrates and
proceeding with the canal around its curvature ; not
indeed ending there, for it may be traced on, consi-
derably shrunk in volume, even to the glans penis :
the continuation of it being the part corresponding to
the corpus spongiosum in human anatomy, a name it
hardly merits in this instance. It has a cellular ar-
rangement internally which we may regard in the same
light as the spongy structure of the glans itself: in-
deed, if we might be allowed here to draw a comparison
between these parts in a man and in a horse, the
spongy body being more developed in the penis of the
former, the glans in that of the latter, we should say
that the glans was an expansion of the corpus spongi-
osum, and that the glans in the horse and the corpus

The Prostrate Glands. 76

spongiosum in man bore strong evidence of some pecu-
liar venous arrangement.

The Prostrate Glands.

These bodies are three in number: a sinofle laro;e
one situated at the neck of the bladder corresponding
to the gland of the same name in the human subject ;
and two small ones which answer in situation to two
little glandular bodies occasionally met with in man,
named from their discoverer Coivsper's glands.

The great prostrate embraces the neck of the
bladder and incipient portion of the urethra, both
superiorly and laterally, being placed between those
parts and the intestinum rectum ; consequently it is
supported by the two former. It is firmly bound to
these parts by cellular adhesion ; and has also a cellu-
lar connection in front with the vesiculae seminales, and
above with the rectum. We distinguish in this gland
two lateral lobes and a uniting middle portion, which in
man Sir E. Home has described as the third lobe, in
consequence of its assuming frequently the lobular
form when in a state of disease. The lobes are enve-
loped in incompact cellular cases, have exteriorly a
conglomerate disposition, and are of a palish brown
color. Internally, this body possesses a spongy or cel-
lular structure, diffused through which are sets of thin
membranous tubes, very large for the size of it, which
are readily inflated, and then are seen to open, through
orifices before described, around the base of the veru-
montanum. The gland secretes a whitish liquor re-
sembling thin mucus, which mingles with the sperm
at the time of its ejection, but for what particular
purpose has not been satisfactorily determined.

76

The Prostrate Glands.

The lesser prostrates are placed at the sides
of the urethra contiguously to the posterior part of the
bulb, where they lie upon the branches of the ischium.
Each of them is about equal in bulk to one of the
lateral lobes of the large prostrate. They are included
in loose cellular sheaths continuous with the substance
of the triangular muscle. In figure they are flattened
ovals. In color they are also a pale brown ; but it is a
much lighter shade than that of the large one. Their
exterior is even and indicate their structure to be of
the conglobate kind. The interior exhibits a more
uniform appearance : a longitudinal section through
the middle displays an arborescent membranous struc-
ture, which is seen by the use of the blowpipe to be
the system of excretory ducts, whose papillary termi-
nations in the urethra have been already pointed out.
These glands also secrete a peculiar fluid which is
ejected in commixture with the sperm.

LECTURE LVIII.

On the Female Organs of Generation,

The sexual apparatus in the female are usually
classed for the convenience of description into those
oroans which are external and those which are internal:
the former being constituted of certain parts that ad-
mit of examination without the aid of dissection ; the
latter of such as are so placed that they cannot be
brought into view but by laying open the cavity of
the pelvis. The external organs comprehend the vulva,
labia, commissure, clitoris, and meatus urinarius.

The vulva or pudendum is the broad slit com-
mencing a little below the anus and extending down-
ward between the quarters. A more correct term for
it is the Jissura magna or sinus pudoris, since the word
vulva is not infrequently used to denote the external
parts altogether, taken as a whole. This fissure is
longest and most conspicuous in breeding mares, in
consequence of some loss of tone sustained by the labia
in parturition. The space between the anus and vulva
is what we call the perineum in the female. The two
lateral prominences forming the fissure are

78 On the Female Organs of Generalion.

The labia pudendi. They are composed exte-
riorly of doublings of the common skin, which here
exhibits a particularly fine and soft texture, is hairless
and in most mares black, and is preserved moist and
supple by a 'sebaceous secretion continually exuding
from minute pores in their opposed surfaces. But the
labia owe their bulk principally to adipose substance,
and this accounts for the variations in regard to promi-
nence they undergo in conformity with the age as well
as the embonpoint of the animal. With this fatty
substance is blended a fibrous texture, and so intri-
cately that the one cannot be demonstrated separately
from the other, nor can their mutual connection and
arrangement be minutely made out : this fibrous tex-
ture gives the labia firmness, resistance, and elasticity.
Between this mixed substance and the skin we find
scattered fasciculi of pale fleshy fibres : these come
from the perineum, grow larger and more conspicuous
,,as they descend, and form a union below the inferior
commissure with similar fasciculi coming from the
opposite labium. Some consider these fasciculi collec-
tively as forming a distinct muscle, and give them the
name of sphincter vagina. They will unquestionably
perform such an office ; but, I know of no occasion on
which they appear to be so manifestly called into
action as when a mare, just after staling, is ejecting the
stagnating drops of urine from the vagina by repeated
eversions of the labia and os vaginas. The labia are
lined by a mucous membrane (the same as that which
lines the vagina) which is continuous with the skin
covering them externally, has a smooth humid surface,
a pinkish hue, (unless it be at the season of the vene-

On the Female Organs of Generation. 79

veal oestrum, when it is deeply reddened,) and is perfo-
rated by the discharging mouths of numberless mucous
follicles.

The Commissures are the parts uniting the labia
above and below. The svperior cornmissure is extended
into a sharp angle and joins the perineum ; the inferior
is obtuse or rounded off, and is bounded by a hollow,
the fossa navicularis of some, at the bottom of which is
lodged the

Clitoris. This miniature resemblance of the male
organ is brought into view by widely dilating the
vulva ; and not only in its appearance is it strikingly
like the penis but it is found to bear the same close
comparison in structure. Its extremity is invested in
a doubling of thin and delicate skin which is hairless
and commonly marbled, or, if not, black, or wholly
white : this part corresponds to the prepuce of the
penis. It is firmly attached to the pubes by two short li-
gamentous prolongations, forming its roots, which unite
into a cylindrical body, from two to three inches in
length in a state of distention, and this consists of two
spongy canals separated by a pectinated fibrous parti-
tion and inclosed within a dense, firm, white tunic : in
fact it is a structure altogether the counterpart of the
corpora cavernosa penis. To this is added a bulbous
end similar in form and composition to the glans penis ;
and through it is a perforation out of which may be
squeezed a sebaceous matter that serves to anoint the
part and preserve its aptitude for that sensual enjoy-
ment of which it (as well as the glans penis) is known
to be peculiarly susceptible. To the clitoris belong a
pair of muscles named singly the

Erector CHtondis. They take their origin from the

80 The Internal Parts.

perineum, where their fibres are mingled witli those of
the sphincter ani, and are inserted into the upper and
back part of the cHtoris. Their office is to erect that
body and protrude it into the vagina in the act of
coition.

The meatus urinarius may also be shown with-
out the aid of dissection, and this is a stage of the
inquiry in which we ought to make ourselves well
acquainted with its situation ; but, as it is united in
structure with the vagina, I shall postpone its consi-
deration until I have described that canal.

The Internal Parts
Are the vagina, uterus, Fallopian tubes, JimbricE, and
ovana.

The vagina is a musculo-membranous canal of
large dimensions extending from the vulva to the
uterus.

It is situated within the cavity of the pelvis, having
the bladder below and the rectum above it, to both of
which it has broad cellular attachments in addition to
the reciprocal connection of all three parts through
reflections of peritoneum. To the rectum it is closely
and firmly attached, by cellular membrane, along its
upper side ; to the cervix, and to the upper half of
the body of the bladder, which is not covered by peri-
toneum, its inferior and anterior part is connected by a
broader and looser cellular band \ and the extreme
parts of the canal in front, both superiorly and infe-
riorly, are aj)plied against the peritoneal pouches
formed between the uterus and rectum above, and the
uterus and bladder below.

The figure of the vagina, when it is distended, is

The InteriMl Parts.

81

that of an oblong cylinder ; but in the collapsed state
its sides are in contact, and it will vary its form ac-
cording to the full or empty condition of the bladder
and rectum ; and when they, especially the latter, are
distended the lono- axis of the canal will be from side
to side, with the exception of its orifice which will have
the long vertical diameter preserved by its union with
the vulva. The most capacious part of the canal is
the posterior, there it even exceeds the dimensions
either of the bladder or rectum ; the part joined to the
meatus urinarius is considerably contracted, but from
thence it gradually widens to the outlet.

The leno th of the canal is about eiohteen inches. Its
course is horizontal : its axis however does not exactly
preserve the straight line, it rather shows an inclina-
tion to the curve of the rectum.

The vagina at its commencement from the vulva is
much thicker in its parietes than elsewhere, which is
partly owing to a coating of strong muscular fibres,
and partly to two cellular or cavernous membranous
bodies, one upon either side, which have some resem-
blance in structure to the interior of the glans penis ;
they are inclosed in membranous coverings, surrounded
by adipose substance, and show signs internally of
having recently contained blood. I know of no appel-
lation in use for these bodies : M. Girard calls them

hulbes vaginah ; " I see no impropriety in naming
them the corpora cavernosa vagina.

The vagina in composition is partly muscular and
partly membranous. The orifice of it is clothed in that
strong, red, circular, fleshy band which forms the
sphincter vaginjE, and the adjoining part of the canal
is also encircled by some considerable fleshy fasciculi ;

PART III. G

82

The Inteiiial Parts.

but the part most compacted, and most thickly and
regularly coated with muscular fibres, is that which is
contracted — which receives the urine as it flows from
the meatus urinarius, though the fasciculi hereabouts
are not so red, nor so strong, as those blended with the
sphincter. Farther forward than this the vagina is
substantially composed of membrane ; there are indeed
colorless fibres taking various directions scattered over
its surface, but they present no very unequivocal marks
of muscularity though they are commonly considered
to be of that nature : fibres apparently similar to these
are also found underneath the red fasciculi posteriorly,
but there they take a longitudinal course.

The membrane of the vagina, the part of which it is
integrally constituted, is one of the mucous class, and
one that possesses considerable density, extensibility,
and resistance. Its exterior surface is rough and floc-
culent from the adhesion of muscle and other parts.
Its interior is smooth and polished, humid from secre-
tion, and has a very pale pinkish cast ; unless the mare
be under the influence of the venereal oestrum, and
then its redness is considerably heightened and its
secretion abundantly augmented. In the ordinary
state this membrane is thrown into folds, larger in
breeding mares than in others, technically called
ruga, which proceed without much regularity from its
outlet to its uterine end. Follicles furnishing the mu-
cous secretion are scattered about underneath the
membrane ; and their orifices are generally most con-
spicuous within the more capacious part of the canal.

Considerably in advance of the clitoris, altogether
about four inches in the collapsed state from the en-
trance of the vulva, is an opening leading from the

T/ie Liten/af Parh. 83

lower part of the canal large enough to admit with
ease any one of the fingers : this is the ori/ice of the
meatus urinarius, and it is a part with the situation of
which we cannot be too famiUar as upon the knowledge
will principally depend our skill in passing the cathe-
ter. The conduit into which it leads is about two
inches in length ; and its course is downward and
forward : it is surrounded below by the muscular fasci-
culi of the vagina, and covered above by its lining-
membrane. The instrument therefore (which should
have more curve than is commonly given to it) must
be introduced so as to follow this oblique direction,
which will be accomplished by elevating* the handle of
it as soon as the point is pushed into the meatus. The
orifice of the meatus is guarded by a doubling of the
vaginal membrane, which hangs over it and serves the
purpose of a valve : care must be taken to elevate this
by means of the instrument ; or, should there be any
difficulty experienced in doing this, the left hand may
be carried per vaginatn to the part itself as an assistant.

The large and conspicuous cauliflower protuberance
at the bottom of the vagina, is the cervix uteri : it will
be described with the

Uterus. The wofub is a hollow, musculo-mem-
branous organ, united to the anterior part of the va-
gina, and destined for the reception of the fruits of
impregnation.

The uterus of the mare is one of a striking and
peculiar figure ; its bodi/, which is the bulky, oblong
part, bifurcates anteriorly into two comua or horns : I
hardly know what the whole is like in figure, unless
the vasrina be taken with it and then in a mare that
has ,never been fecundated they very much resemble

G 2

84

The Internal Parts.

altogether an insect of the beetle tribe, the vagina
representing the bottle or body, the uterus the head
and netfk, and the cornua the horns. But, during the
period of gestation the womb undergoes an almost
incredible augmentation in volume ; and it never after-
wards recovers its original or virgin state of contraction.
We distinguish then in the uterus, body, horns, neck,
and mouth.

The body is the oblong or cylindrical part, growing-
out of the anterior portion of the vagina, in the centre
of which it is terminated internally by the os uteri, and
is giving origin in front to the horns. Its upper and
under surfaces are convex, most prominent towards the
middle ; its corners or angles are round ; and it is
evidently formed altogether to give capaciousness with-
in. This part lies wholly within the pelvis, between
the bladder and rectum, and is entirely covered by
peritoneum.

The cornua or horns, having risen from the body at
an acute angle with each other, take a progressively
divergent course to the loins under the broad plates of
the ilea ; they are therefore not entirely confined to the
pelvic bason. Their length and size will be much
greater in breeding mares than in others, though their
volume altogether will be less when compared with the
capacity of the uterus : indeed in virgin mares the
diameter of a single horn is little exceeded by that of
the womb itself. In figure they are cylindrical ; they
bend upward in their course ; and they terminate in
round extremities, to which are loosely appended the
ovaries, through the medium of the Fallopian tubes.

The cervix or neck of the uterus is the rugose portion
protruded backward into the cavity of the vagina.

The Internal Parts. 85

which from its flower-like appearance the French have
fantastically named "la fleur epanouie it is a part
however that can only be said to be demonstrable in
a virgin uterus in the undistended state — inflate these
parts and the cervix will disappear ; and one that
during gestation undergoes certain remarkable changes.
The vertical slit or oval-shaped aperture in its mid-
dle is the OS uteri or mouth of the uterus. The peculiar
florulent aspect of the cervix is owing to its being
enveloped in a prolongation from the lining mem-
brane of the uterus, which is uniformly puckered into
many ruga as it passes through the os uteri : around
the sides of the cervix these rugae become continuous
with those of the vaginal membrane. This is a part
that receives an especial abundant supply of mucous
secretion.

Independently of its union with the vagina, the
uterus is confined in its place by two broad productions
of peritoneum which attach it to the sides of the pelvis,
named the ligamenta lata uteri. They are formed in this
manner — The peritoneum which is reflected from the
bladder covers the under parts of the body and horns of
the uterus, their upper parts receiving a similar covering
from another portion of the same membrane derived
from the rectum ; the two portions then unite at the
sides of the uterus and continue in union to the oppo-
site parts of the pelvic parietes : this arrangement of
the membrane in fact divides the pelvis into two cavi-
ties, or rather blind pouches, one existing between the
uterus and bladder, the other between the uterus and
rectum ; at the same time it serves to connect these
parts mutually to each other. The cervix consequently
receives no peritoneal covering. These ligaments sus-

m The Internal VaHs.

tain between their layers the vessels and nerves belong-
ing to the organ, preserve its equilibrium during gesta-
tion, and aid in retaining it in its proper centrical
situation.

Underneath the peritoneal tunic of the uterus, united
to it by a short cellular tissue, is a dense fibrous struc-
ture possessing a considerable degree of strength and
extensibility, which is generally thought to be muscu-
lar; and the fibres have certainly that appearance,
though their direction is very various, some running
circularly, others deeper-seated longitudinally, and
others again decussating these. But, about the cervix
in particular, where the fibres are strongest, most col-
lected, and often have a pale bloody tinge, the muscu-
lar structure is most assumed ; though, after all, the
presumptions of its muscularity seem rather to be drawn
from a physiological than an anatomical source.
During the period of gestation this tunic not only ex-
periences considerable extension, but may be proved to
undergo veritable accretion. Inwardly it is opposed
and adherent to the internal tunic ; but their connec-
tion, which is also cellular, is looser than that existing
between it and the peritoneal covering.

The cavity of the uterus, having the same irregular
figure as the exterior, has three outlets : — one of con-
siderable size communicating with the vagina, through
the OS uteri ; two others of very small size through the
extremities of the cornua, leading into the Fallopian
tubes, the situations of which are denoted by two little
whitish eminences visible upon the internal surface.
The membrane lining the cavity is one of the mucous
description ; it has a more vascular and villous appear-
ance than that coating the vagina, but, like it, is thrown

The Internal Paris.

87

in the collapsed state of the organ into numerous rugae,
which pervade the cornua as well as the body and bear
some comparison to an irregular network : these rugae
are larger and looser in mares who have bred several
foals. The surface is everywhere copiously furnished
with mncous secretion by subjacent follicles whose ori-
fices are visible to the naked eye.

The Fallopian tubes are two trumpet-shaped or
conical canals, having a remarkably serpentine course ;
running within the folds of the ligamenta lata from the
extremities of the cornua uteri to the ovaria.

The tube commences by an aperture in the cornu
having an elevated whitish margin, which is scarcely
large enough to admit a small silver probe ; from this
it proceeds forward, folded in peritoneum, and extreme-
ly convoluted until it reaches the ovary, to which it be-
comes attached ; it then begins to enlarge in its dia-
meter, grows less convoluted, and serpentines along
the posterior side of the ovary, until it has got to the
fissure of that body, at which part it ends in a fringed
doubling of membrane, named the corpus Jimbriatum,
by a funnel-shaped irregular opening, which is turned
backwards, large enough to admit an ordinary-sized
black-lead pencil. The corpora fimbriata hang over the
fissures of the ovaries, concealing them indeed from view,
and are unattached and float about loosely with those
bodies w ithin the abdominal cavity.

These tubes, when stripped of their peritoneal en-
velopes, show a fibrous texture, and when opened ex-
hibit a rugose, villous, raucous surface, very similar to
that of the internal membrane of the uterus. They
are amply supplied with blood-vessels which make their
way to them between the layers of the broad ligaments.

88 The Internal Parts.

The ovARiA or female testicles are two egg-shaped
bodies, situated farther forward than the Fallopian
tubes within the cavity of the abdomen, at the distance
of an inch and a half from the cornua uteri. They
receive close coverings from the anterior portions of the
ligamenta lata, by processes of which they are loosely
attached to the spine in their situation beneath the ilea
and a little behind the kidneys : indeed the left ovary
has a peritoneal attachment to the left kidney. So
that if it were our intention to extract them, the inci-
sion should be carried along the crista of the ileum, and
the hand introduced in a direction backward and in-
ward.

These bodies are about the size of walnuts. They
are not regularly oviform : they have deep fissures in
their posterior sides which are occupied by the corpora
fimbriata. Taking them and the Fallopian tubes toge-
ther, they bear a striking resemblance at first view to
the testicles and their ducts in the male.

Underneath their peritoneal coverings, the ovaries
have whitish fibrous tunics, dense and inelastic in their
texture, which warrant the comparison generally made of
them to the albugineous tunics of the testicles. Inter-
nally the ovaries are composed of a whitish spongy sub-
stance, in which are in some instances found little vesi-
cles containing a yellowish glairy fluid, in others one
or more dark yellow or brownish substances named cor-
pora lutea : the vesicles are the ova which from im-
pregnation take on further development ; the corpora
lutea denote the parts from which vesicles have burst,
and consequently only exist in the ovaries of those
mares whose organs have been engaged in the genera-
tive process. Prior to the age of gexual intercourse

The Mammce. 89

these bodies are small and white ; but as soon as the
season of copulation is at hand, they grow large, red-
den externally, and present many yellow spots or
streaks throuo;h their substance within.

The arteries supplying all these parts are — 1. The-ua-
ginal artery, a branch from the internal iliac, which
accompanies the obturator artery and then dips down
upon the side of the vagina, upon which it branches
out in various directions, sending some ramifications in
its way to the rectum, and transmitting others to the
uterus and bladder. 2. The uterine artery, a branch
from the external iliac, coming off after the ilio-lumbar,
and distributing its branches principally upon the cor-
nu uteri. 3. The spermatic artery, coming from the
aorta, is convoluted in its course, and supplies the ova-
rium, corpus fimbriatum, and Fallopian tube.

The nerves are derived from the hypogastric plexus.
Both the vessels and nerves take their passage between
the layers of the broad ligaments, insinuate themselves
underneath the peritoneal covering, obliquely pierce
the substance of the muscular tunic, and ramify ex-
tensively between it and the internal membrane.

Before I proceed to the physiology of generation I
shall give the description of two glands, which, though
unconnected with these organs in an anatomical point of
view, are in function concurring to the same important
end — the continuation of the species : these are the

MammcE.

The mammse, vulgarly called the udder, are two flat-
tened oval-shaped bodies depending between the thighs
from the posterior and inferior part of the belly.

In quadrupeds, with but few exceptions, this is the

90

The Mamma'.

situation of the mammae ; in the human species and in
the ape tribe they are attached to the breast. The ad-
vantages resulting to the quadruped, who has no power
of erecting himself or handling his young, from this si-
tuation of the mammae, are, that they are well protected
by the trunk above and the thigh on either side from ex-
ternal injury, that they are conveniently placed for the
foal, and that they do not in the least interfere with
progression.

In fillies and virgin mares the udder is so small that
there hardly appears to be any ; and in mares who have
not had more than one or two foals it also regains nearly
its original flatness ; but in this last instance the dugs
are commonly left larger, looser, and more pendulous
than formerly, in consequence of the reiterated exten-
sion of them by the foal : a circumstance on which we
may rely with tolerable certainty for a knowledge of
this fact. In mares who have had several foals the udder
remains prominent or pendulous and has a flabby feel ;
and this is a state we cannot well mistake. Towards
the latter end of gestation this part undergoes further
evolution, swells and grows firm to the feel, and be-
comes distinctly visible as we stand behind the mare.
Within a few days of parturition secretion begins and
the udder grows turgid with milk ; it does not however
acquire its full distention until the foal has drawn it for
a few days, from which time it maintains its volume
with little variation during the period of lactation.
Soon after the foal begins to forsake the teat the secre-
tion of milk diminishes, and this is followed by a con-
traction of the bag which goes on gradually until it has
resumed nearly or quite its former flatness. In a state
of full evolution then the udder assumes a hemispherical

The Mamma:. Q\

form, and acquires a firm plump feel ; at other times it
is soft, flabby, more or less pendulous, and has no defi-
nite figure nor volume.

The outer covering of the udder is an extension from
the common integuments of the belly ; it is thin and
fine in its texture, is commonly black, and is clothed
with a few long downy hairs growing thinner as they
approach the dug, immediately around which the skin
is without hair. Underneath the skin, adhering to
it by intervening cellular membrane, is spread over the
gland a white, elastic, ligamentous covering, inter-
spersed with several fibrous bands, which is derived
from the faschia superficialis abdominis : this serves to
give support and compactness to the glandular struc-
ture, and in consequence of detaching processes into
the interior among the lobules to strengthen their inter-
union one with another.

The interior of the mamma has a light yellowish as-
pect, and evidently possesses a lobulated structure,
which is held together by a fine cellular tissue here and
there interspersed with granules of fat. It is consti-
tuted of glandular masses, irregular in magnitude and
form and loosely connected one with another, each of
which masses is composed of a number of lobules closely
compacted and united together : a composition altoge-
ther that accounts for the loose or knotty feel which the
gland is well kilown to possess. These insulated lobu-
lous portions receive small arteries in numbers from the
parent arterial trunk, from whose terminations arise
(we do not precisely know in what manner) the tubuli
lactiferi. These numberless little tubules, by repeatedly
conjoining one with another, become at length several
demonstrable canals, radiating from every part to as-

9^ The Papilla.

semble in the teat, still uniting one with another in
their course, and occasionally dilating into considerable
reservoirs for holding the secretion. The lactiferous
conduits are continued through the substance of the
dug, wherein during its relaxation they are so serpen-
tined or coiled that milk cannot spontaneously flow
from them ; but in the distended state of that body, or
when it is drawn out in the act of suction or milking,
these ducts are rendered straight, and the milk, either
from internal or external pressure, is readily forced out.

The papilla or teat, which depends from the most
prominent part of the udder, near its middle, is conical,
black, and hairless. Its tegumental sheath is of the
same description as that covering the bag, from which
it is derived, only it is perforated at the apex by three
holes to give issue to the milk ; and underneath this is
a second tunic which comes from the elastic ligamen-
tous covering also of the gland. Through these open-
ings, one of which is commonly conspicuous for its
size, the milk is discharged from the conduits of the
lactiferous tubes. When the udder becomes charged
with milk it flows into the teat and distends it ; and as
the secretion is probably influenced in animals, as
it is in the human subject, by anxiety for the young,
the animal evinces this feeling by a state of distention
, of these parts. The dug, as has been remarked be-
fore, enlarges during the season of lactation, and it
does not afterwards recover its original volume so
nearly as the udder itself does, a fact, I repeat, that
may lead, when the first sign is wanting, to the disco-
very of mares that have bred.

Sucking is apparently an operation purely mechanical.
The teat is seized and so closely compressed by the lips

The Papilla. 93

of the foal that the imbibing effort which follows has a
tendency to produce a vacuum in the lactiferous tubes
now rendered straight from extension: this is coun-
teracted by the pressure of the atmosphere upon the
surface of the udder, and the consequence is, that the
milk is forced from its reservoirs into the mouth in the
same manner that water is impelled into the barrel of a
syringe from raising the piston.

LECTURE LIX

✓ ys^^ >■ ^^^^ ^V^/- ✓•^^ ✓^^-^ *v*^ ^-^-^ r^-^N^

0« ^Ae Physiology of the Organs of Generation,
Male and Female.

Xn the course of our inquiries into the anatomy of
these organs we discovered some remarkable points of
correspondence between them in the female and in the
male, to wit, the clitoris and penis, the ovaria and
testes, and the os uteri and glans-penis ; but now that
we have come to their physiology we shall find that
they are so mutually dependent for the exercise of
their functions and conspire in such manner together
to the common object of these functions, that they will
conveniently and perhaps advantageously come into
the same physiological investigation. This common
object is no less than the devolopment and reproduc-
tion of new beings. It might be supposed that the
part the male takes in fecundation is comparatively a
very unimportant one ; it must be remembered however,
that the copulative act is the essential first cause, that
therein the action of the organs is mutual and sympa-
thetic, and that the result is the generation of a new
animal bearing a likeness to one or both of the parents ;
from which it would appear, although the physical

On the Phyaiology of the Generative Organs. 95

part of the male is simply to project the sperm into the
female, who alone has the power of rendering it effica-
cious, that the influence of the sperm is much greater
in the generative process than we seem to have any
notion of, or at least than we have been able to reveal
the nature of in physiology.

The office of the testes being to furnish the fecun-
dating liquor (which we call semen or sperm) we consi-
der* them to be the most important part of the male
apparatus. These organs do not descend into the
scrotum for some time after birth, and it is not until
the animal is considerably advanced in growth and
strength that they carry on their glandular functions :
this, the period of puberty, is denoted in animals as
well as man by some remarkable changes both in body
and propension. In man the pubes become covered
with hair, the beard makes its appearance, the voice
alters, the sexual organs undergo their full development,
menstruation begins, and the mind is taken captive by
a novel and irresistible influence. In quadrupeds this
epoch is marked by luxuriant growth of hair, particu-
larly of the mane and tail, by alteration in the voice,
by the production of the crest or horns or both, by the
emanation of a peculiar odor from the body, by the
further evolution of the organs, and by the manifesta-
tion of the oestrum in the female and of an indomitable
lustful passion in the male. All that we know about
the secretion of the sperm, is, that it is elaborated in
and by those capillary ramifications of the spermatic
artery that have some indefinable communication with
the tubuli seminiferi, and that these tubes are always
to be found full of secretion ; of which fact, in addition
to the anatomical evidence formerly given, we have this

96 On the Phydology of the Generative Organs.

proof, that ligature of the spermatic arteries, though it
does not mortify the testicles, destroys the prolific
powers of the animal. In regard to the semen itself,
it is a white viscous fluid, having a peculiar faint odor,
and has been found to contain myriads of animalcule
or vermiculi, as they have been also denominated from
their supposed resemblance to worms ; not only how-
ever have conjectures been broached about the form and
size of these almost inconceivably minute corpuscules
of vitality, but chimeras have found their way into
print even of their sex and mode of generation. To
chemical analysis, according to Girard, the horse's
sperm yields four-fifths of a peculiar animal matter ; the
remaining ingredients being mucus, muriate of potash
and soda, and carbonate and phosphate of lime.

The removal of the testicles not only deprives the
animal of the power of impregnation but even renders
him after a time insusceptible of any sexual appetite,
and is attended with other enervating consequences.
Sir A. Cooper has informed us, that a man from
whom he took both testicles continued to feel venereal
desires for some months afterwards, and to experience
the usual emission and sensations in the performance of
the coital act, but that both the power and inclination
gradually grew weaker during the time, and that he
became so perfectly emasculated at the expiration of a
twelvemonth that he was not even capable of an erec-
tion. In like manner castration operates in horses, not
only depriving stallions of their amorous fury but con-
verting the most outrageous into meek and even spirit-
less geldings : in addition to which we have to notice
this curious fact, that, should the operation be per-
formed at the time that the animal is changing or about

On the P/u/siologi/ of the Generative Organs. 97

to change his coat, the process will be interrupted or
suspended altogether until the return of the shedding
season, and in the instance of the deer the horns will
not be cast as usual during that year. But the loss of
one testicle does not take away or even diminish (that
we have any proof of) either the procreative faculty or
the sexual appetite : rigs appear to get foals as well
and to cover as frequently as stallions, nor do we per-
ceive any difference in men under such circumstances ;
we may therefore conclude that the popular notion of
their comparative imbecility is not well founded. There
is this remarkable difference however in the generative
functions of animals in general and those of the human
species, that the former only show themselves in vigour
at certain seasons whereas the latter are in a continual
state of activity ; and this seems to go far to account
for the comparative moderation and governable nature
of the amorous passion in the latter : this periodical
excitement has such an influence on the testicles in
birds that they grow large in the coupling season, but
shrink into very small size when they are no longer re-
quired to furnish secretion.

The use of the vesiculae seminales has long aflbrded
subject for disputation, and even at the present day
admits of more than one explanation. The ancients con-
ceived that they generated the semen. This erroneous
notion was no sooner discarded than followed by the
plausible one, that, although they did not form, they
contained semen, and were to be considered as reser-
voirs for that fluid. Mr. Hunter was the first to
erect a doubt in opposition to this theory ; and he
ultimately adduced some ingenious experiments toge-

PAKT rii. H

98 On the Physiology of the Generative Organs.

ther with several well-selected cases to show that this
opinion was not founded upon fact. Among other ob-
servations made by this distinguished physiologist, he
discovered that these bodies contained to all appear-
ances and tests the same fluid in geldings as in stal-
lions ; and that in men who had for a long time before
death been deprived of one testicle there was no disco-
verable difference whatever in the properties of the fluids
found in the rightand left vesiculse. In fine, if Mr. Hun-
ter's researches into their physiology be not of that
character that would warrant us in coming to the same
conclusion with him ; at least they have led to a de-
monstration that the vesiculae do themselves furnish
a particular fluid of the nature or appearance of mucus,
and that the semen, if it really does ebb from the
direct channel into these bodies, is therein so mixed
with their secretion that it evades the ordinary tests
of detection ; and further, that in this diflfused or
diluted state it is ejaculated from the penis. This
doctrine — that no semen enters the vesiculae, requires
some satisfactory explanation of the production of
seminal emissions in the very short space of time in
which they are known to be demanded and furnished.
Mr. Hunter supposed that the testicles were at the
moment excited to action sympathetically with the pas-
sions of the mind ; and we may add that the secretion
which it is known they always contain probably requires
but little addition to render it available : the extreme
length, exility, and tortuosity of the seminal tubes
however appear to weaken much the force of this sup-
position ; while, on the other hand, the opinion that
semen is collecting at other times within the vesiculae

On the Physiology of the Generative Organs. 99

receives no small weight from the experimental result,
that fluids injected into the vasa deferentia find their
way into these sacs.

The sperm receives further augmentation at the time
of its emission from the prostrates. The secretion fur-
nished by these glands is white, opaque, thick, and
viscous, bearing considerable resemblance to mucus,
and appears to be well adapted as a vehicle for the
semen ; the ejaculation of which it is believed to facili-
tate by the addition made to the bulk of the latter, and
by the glibness it diffuses over the seminal fluid as it
passes along the urethra. So far as a menstmum or
vehicle is operative, it may be said also to contribute
to the efficacy of the semen, injected, diffused, and
mingled with other secretions as that fluid must be
in the organs destined for its reception in the female.

The accomplishment of sexual congress requires that
the penis be in a state of erection : the testicles at
the time are drawn up close to the belly by the cre-
masteres, and the contractile powers of the vesiculae
and vasa deferentia, aided by the accelerator urinae and
levatores ani, are supposed to be exerted in the ejacu-
lation of the seminal fluids. The distention of the
penis with blood, which is the cause of erection, is
occasioned by an increased action of the pudic arteries
and the consequent accelerated influx of blood into the
corpora cavernosa and thence into the glans penis, in
which accelerated local action the veins do not partici-
pate from the interposition between them and their
arteries of this spongy and vascular structure ; the
result therefore is congestion of blood within the
penis, and this effect is considerably promoted as the
distention increases by the mechanical obstruction to

H 2

100 Oti the Physiolog}/ of the Generative Organs,

the return of blood occasioned at its root by the approxi-
mation of the organ to the pubes and the compression
of the trunks of the veins there between it and the
bone.

In the rutting or covering season animals are found
to grow restless and unruly, and to be disposed to ram-
ble from their pastures ; indeed, unless permitted to
seek their mates they will often refuse their food, and
even undergo considerable privations, suffering extenu-
ation of body partly from this cause and partly from
nervous disquietude : so domineering and influential in
the system is the periodical sexual passion. Numerous
and remarkable are the instances in proof of this ardent
amorous attachment among quadrupeds : the train of
followers allured by a bitch at heat, the number of
miles a dog-fox is known to ramble in quest of the
female, and the implacable fury of the bull, are among
the more familiar of them. No sooner does the stallion
come to the knowledge of the horsi/ condition of the
mare than he becomes fired with an energy and a
courage unknown to him at other times ; nothing will
pacify him so long as he imagines she is within his
reach, he grows impetuous and unmanageable and re-
quires means of restraint unused before to confine him
in his stable or prevent him from breaking loose when-
ever he is led out. At the time that he is suffered to
approach the female his whole frame exhibits the height
of animation : his nostrils are dilated to their utmost
to gratify his lecherous sniffs ; his eyes flash with ner-
vous and passionate expression ; his actions and
carriage altogether, Avhile they display gracefulness,
manifest intense vigor j and he evinces no less irascibi-
lity towards any one who would thwart him in his

Oh the Physiology of the Generative Organs. 101

impetuous course than lustful ardor for the object
before him. The presence of this influence in the sys-
tem is attended in some animals with a peculiar fetor of
from the body, and a remarkable hardness and toughness
of muscle which renders them unfit for food : the he-
goat is a striking instance of these changes ; but they
are also manifested by the stag, ram, bull, and others.
Absorption of accumulated semen has been offered by
way of assigning a cause for these phenomena ; and,
granting the fact — one that the constant state of pleni-
tude of the seminiferous tubes and the presence of
numerous absorbents in the gland render highly pro-
bable, the rationale, as far as it goes, is very plausible,
supported as we find it to be by the link in this chain
of observations, that castration removes or greatly miti-
gates these effects.

By implanting such a vigorous and irresistible im-
pulse into the sensual constitution of animals has Na-
ture excited the congress of the sexes and insured the
perpetuation of their species ; and so salutary is the
moderate or seasonable performance of this act that
animals are found to be improved both in health and
strength by it : but the line of moderation is not to be
stepped over with impunity ; preternatural excitement
of the organs — overstraining their functions, never fails
|o shorten the term of their capabilities to renew their
offices, and, if carried to excess, to prove highly in-
jurious and destructive to the system altogether. It is
well known that bulls who have much gregarious inter-
course seldom retain their lustful vigor longer than
two or three years ; and that stallions also who cover
many mares in the course of the season suffer by it a
permanent reduction or debility of stamina.

102 On the Physiologij of the Generative Organs.

Let us now pass over to review the functions of the
organs belonging to the female. I have already made
some allusions to what is called the covering or rutting
season^ by which is meant that period of the year dur-
ing which the female parts are in a state of aptitude for
giving due effect to the sperm conveyed into them by
the penis of the male. This periodical condition of the
organs furnishes us with a mark of distinction, as it
relates to generation, between the human female and
animals in general. Woman becomes at the age of pu-
berty, and continues to be until the decline of life, the
subject of a discharge from these parts which from its
reo-ular return with the moon or month has got the name
of catamenia or menses ; this flux has been found to con-
sist of blood destitute of fibrine, and is supposed not to
be a mere sanguineous effusion but to result from a sort
of secretory process carried on by the mucous mem-
brane of the uterus. The natural effect of this dis-
charge is, to preserve the organs in a perpetual fit state
for conception ; for it is found that women who do not
menstruate from the uterus do not conceive. Animals
are not so by nature. Though there are some appear-
ances, vulgarly denoted by the term heat or heats, that
might lead us to an opposite conclusion, such as deter-
mination of blood to the parts, more or less mucous dis-
charge, and that occasionally even tinged with blood, yet
this is but an uncertain and infrequent return, much influ-
enced by the season, by no means assuming that regular
and determinate character of the menses in women, and
is one that only continues during the influence of the sex-
ual oestrum, and so long, but no longer, sustains the
organs in a fecundating condition. Mares become the
subjects of this salacious influence at the approach of

Oft the Physiology of the Generative Organs. 103

summer, when they are said to be horsing, and show it by
redness and prominency of the vulva, and by the emis-
sion at intervals in considerable quantities of a whitish
mucous fluid, the odor of which proves a peculiarly po-
tent incentive to the male : these appearances are found
to be accompanied with general turgescence, reddening,
and increased excitability of the whole genital appa-
ratus, and more particularly of the uterus which now
opens its mouth, dilates, and disposes its cavity for the
reception of the prolific fluid. Some mares will take the
horse shortly after they have foaled ; but the ninth or
tenth day is the regular period of return of the oestrum,
which ordinarily continues for four, five, or six days ;
after which it commonly returns at intervals of three
weeks. Among the circumstances, natural and ar-
tificial, that have any influence on the production or re-
turn of the oestrum, we may mention condition, tempe-
rature, and various artificial stimulants as the principal.
Animals who are in the vigour of health, without show-
ing much disposition to obesity, who live well, are not
over-worked, and particularly such as are fed upon sti-
mulating provender, are more so disposed than others :
indeed mares low fed, ill treated, and hard worked,
seldom show that they are horsing at all. Animals in
general, particularly birds, copulate during the spring-
er summer ; to which fact may be added another, though
less notorious not less true, to demonstrate the opera-
tion of heat, which is, that animals transported from
warm to cold climates seldom copulate and more rarely
breed after their removal : mares are commonly found
horsing in the month of May or June. There can be no
doubt but that there are various substances promotive
of this condition of the parts, and their eflect appears
to be simply that of excitation ; certain of these will

104 On the P/n/siologi/ of the Generative Organs.

operate through the system, the others are mere local
stimuli : some grooms, I am told, are in the habit of
very roughly using such substances and occasionally in-
flicting thereby considerable local injury. Animals are
also capable, other circumstances favoring, of having
certain salacious sensations aroused in them by the
male which proves a great promoter of the oestral con-
dition : this is well known to breeders, who are in the
habit at the proper season of having mares they are de-
sirous to have fecundated frequently teased by the stal-
lion. Age must also be taken into this account: mares
are incapable of fecundation prior to the twentieth
month or second year of their age, and become barren
in advanced life.

The horse no sooner quits the mare after copulation
than she rejects, it would appear, the greater part if
not the whole of the prolific liquor she has just received ;
to prevent which it is a common practice with grooms
to press the tail or a wisp of straw forcibly against the
vulva so as to close the orifice. There is also a practice
in vogue of dashing a pailful of cold water upon the
loins or quarters, with a view of diverting the excita-
biUty of the genital parts. The female ass is often well
beaten or spurred afterwards as a still more eflfectual
diverter. Girard tells us, that the Arabians fatigue
the mare they intend to have covered in order that she
may repose after coitus and so lessen the uncertainty of
being fecundated.

Impregnation ordinarily puts an end to the oestral
discharges by causing permanent closure of the os
uteri ; this however is not invariably the case, for some
mares will receive leaps and appear to be horsing even
at an advanced period of fecundation. It becomes a
very interesting question in opening the abstruse subject

On the Pht/sioiogt/ of the Generative Organs. 105

of the physiology of female generation, to ask to what
part in particular the semen is designed to be applied ;
for, since this fluid is no less than the primum mobile
of generative action it cannot be an affair of indifterence
in what manner it becomes disposed of : it must either
be deposited in the vagina and there remain ; or be in-
jected into the uterus and lodge there ; or pass on
through the Fallopian tubes to the ovaries. However
simple this question may appear, hardly any physio-
logical problem has given birth to more controversy.
Haller says, that he once found semen in the uterus
of a sheep. Mr. Hunter discovered it there in a bitch
that was killed instantly after copulation. Dr. Haigh-
TON has made a series of experiments with rabbits to
throw light upon this subject which have led to some cu-
rious and interesting results. He divided the cornua
uteri, the natural consequence of which proved to be,
complete obliteration of them : this not only destroyed
the power of conception, but all inclination to employ
the means. After this, he divided one tube only, which
in many instances was followed by conception : corpora
lutea, which, according to the Doctor, are never formed
but after conception, were produced on both sides, but
foetuses only on the sound side. But how came it that
conception took place when the communication be-
tween the ovary and uterus was intercepted ? The ex-
periment goes to show, that it is not necessary that se-
men should be brought into actual contact with the
ovary to produce conception, since impregnation was
not permitted until forty-eight hours had elapsed from
the time the tube was divided. But why did not foe-
tuses also form on the intercepted side since it is pre-
sumed that conception actually took place there ? In

106 On the Physio/ogi/ of the Generative Organs.

answer to this the Doctor gives us the experimental
fact, that the division of the tube at any period after
conception but before the germs have passed into the
fimbriae, will equally prevent the appearance of foetuses ;
but, if the rudiments of the new animal have already
passed into the tube, the actions of the parts suffer no
interruption. To what, then, are we to ascribe con-
ception? The Doctor answers, to sympathy. The
subject admits, I think, also of a glimmer of light
from a review of the genital parts in horses especially :
the comparative lengths of the vagina and penis, and
the adaptation in form of the end of the latter to the os
uteri, afford presumptive evidence at least of the design
of Nature, that these parts should come together.

The injection of semen then into the uterus appears
to be all that the female receives from the accession of
the male : the notion that she herself emits any semi-
nal liquor in the act is now dropped ; it being pretty well
ascertained that the said emission is no more than a
mucous discharge from the vagina. A knowledge of
this fact might lead one to inquire whether the office of
the male could not be supplied by artificial means, sup-
posing that we could obtain in every case the proper
masculine Hquor. Spallanzani has proved that this
is practicable : he tells us that " he has succeeded as well
as if the male himself had performed his proper func-
tion ;" and a singular corroborative case is given by
Mr. Hunter ; but my limits are too confined to do
justice to these interesting facts in detail, and there-
fore I shall pass them over.

We have next to investigate the phenomena and ap-
pearances following copulation and conception. On
these points Dr. Haighton's accurate and connected

On the Physiology of the Generative Organs. 107

observations * particularly merit our notice. In rab-
bits (with which his experiments were made) the only
observable difference from the first to the ninth hour
after coition, the animal being in high venereal condi-
tion, was a greater turgescence of vessels of the parts,
as if preparatory to some important action. 2. In twelve
hours after coition projecting vesicles were seen that
had lost their transparency and become opaque and red ;
from which, when punctured, a fluid of the same color
escaped. 3. At 24 hours the vesicles projected
more evidently, and their thickened parietes, mani-
festing the formation of corpora lutea, had become
more apparent. 4. At 48 hours the vesicles seemed
to be in the very act of bursting, and a seraitransparent
substance of a mucous-like consistence was beginning
to protrude from some of them. The fimbriae were
preparing to receive their contents, for they had em-
braced the ovaria to such a degree that only a small
portion of the latter could be seen. 5. In five days and
twelve hours the foetal rudiments had escaped ; but the
cavities of the ovarian vesicles had suffered but little
diminution. Their ruptured orifices were manifest.
6. During the third, fourth, and fifth days there remain
ed but little vestige of cavity, consequently the corpora
lutea may be considered as perfectly formed.

We may consider then, as received facts, that
the germs or rudiments of the future beings exist in the
ovaria prior to impregnation ; that they escape at a
certain time subsequent to impregnation from the ova-
ria into the Fallopian tubes ; and that they gradually
pass backward into the uterus. No sooner has the
oestrum ceased and fecundation is insured than the

* Vol. Ixxxvii. " Philosophical Transactions."

108 On the Physiologic of the Generative Organs.

turgidity and reddening of the ovaria (in common with
the other parts) subside, and one of these bodies takes
on a new action. A little, black, circumscribed tumor
makes its appearance in this ovarium, which is the ca-
lyx or cup wherein is formed or at least contained the
ovum or germ ; after the expulsion of the ovum the ca-
lyx exposes a black cavity which gradually closes in ,
consequence of a thickening and growth of its parietes
and then includes a vesicle containing a yellowish
fluid, and thus becomes what is called a corpus luteum :
a certain mark of impregnation whether there be any
discoverable embryo or not. It is a curious fact that
the fimbriae should spread out, advance, and grasp the
ovarium at the period of the bursting of the calyx and
that they both should be so consentaneous in their ac-
tions. Not however that this law is universally uner-
ring ; for extra-uterine foetuses are heard of, and these
are believed to have fallen into the belly from defective
co-operation, owing to some mysterious cause or other,
in these parts ; indeed, for aught we know this is a
lapsus that may happen much oftener than is made sen-
sible to us, and the fallen ovum come to nothing. Un-
less the ovaria exist then in a sound or efficient con-
dition the female not only loses all amorous desires
but no longer possesses the faculty of procreation : even
the removal of one ovary was found by Mr. Hunter to
have a marked effect on the fecundity of the animal.
Spaying therefore is an operation that reduces the fe-
male to much the same state to what castration does the
male.

It has become a question of some magnitude among
accoucheurs whether it be possible to impregnate a fe-
male a second time in whom fecundation has already

On the Physiology of the Generative Organs. 109

taken place. In consequence of the season of amour
being limited in animals it is not an inquiry that we
can pursue to much advantage ; but instances have pre-
sented themselves in human medicine in which foetuses
of different degrees of development have been discovered
in the same female, and such are usually adduced as
instances of super-foetation ; these cases however have
not been received as conclusive evidence, and so the
point still remains uncleared up.

The primitive source of the new animal and the mode
of its production are subjects naturally creative of more
than common interest in the mind, and have proved to
be the fruitful beds of speculations and hypotheses.
Such of them however as are worthy of our attention
we may include in the three following propositions.
1 . That the foetuses exist ready-formed in the sperm of
the male, and only seek a nidus for their evolution
and growth within the body of the female. 2. That the
germs pre-exist in the female, and only require the
stimulus of the masculine liquor to dislodge and deve-
lop themselves. 3. That the production is a neutral
or rather a mutual one, both sexes concurring in its
formation.

After we have been engaged in examining the various
parts of the complex apparatus destined for the pur-
poses of generation in the female it is rather extravagant
or at least unreasonable to suppose that these several
organs should have been formed merely to afford a ha-
bitation or a nidus to a being already created and only
requiring further evolution and growth ; indeed, know-
ing as we do that the embryo arrives in a very indis-
tinct state of existence and at a very early period or
being within the uterus, were this notion well founded

110 On the Physiology of the Generative Organs.

I do not see what functions there would be left for the
ovaria and Fallopian tubes to perform at all ! This is
an hypothesis therefore that has deservedly met with
but few supporters. The opinion that germs pre-exist
in the ovaries and only require impregnation to develop
themselves, the ostensible father of which is the inde-
fatigable Spallanzani, who first discovered pre-exist-
ent germs in a species of frog, has met with advocates
among the most celebrated physiologists ; though there
are some formidable difficulties in the way even here.
The semen being proved to be indispensably necessary
to impregnate the germ or ovum, where or how does
this operation happen? Dr. Haighton has shown
that the marks of conception, corpora luiea, may ap-
pear though all communication between the uterus and
ovary is cut off ; but that foetuses will not be produced
unless the ova have been received by the tube. This
would appear to show that the ova are rendered prolific
by the semen within the uterus ; but, then, how comes
it that foetuses are now and then brought to perfection
within the Fallopian tubes and even within the cavity of
the belly ? since they can not receive any such semi-
nal contact ? It has been ascertained, if a bitch (say
a greyhound) be lined by several dogs of various
breeds that she will not bring forth more whelps than
if her intercourse had been confined to one, but that
she will probably produce one of each race : the expla-
nation given to which is, that the ova arriving in suc-
cession from the ovaria in the uterus, fall into the semi-
nal fluids of the different dogs. Again, in birds we
know that a single coition is sufficient to fecundate a
great number of eggs though they are produced at dif-
ferent and even remote periods. That the foetus then

On the Physiology of the Generative Organs. 1 1 1

comes from the female in the beginning there appears
but little reason to doubt, especially after we have pe-
rused the mass of evidence brought in support of this
opinion by Spallanzani both from the animal and
vegetable kingdoms ; but, still, the subject is open to
have shadows of obscurity cast over it by some few
facts no less embarrassing in their nature than they are
notorious for their truth, among which may be men-
tioned— the likeness the offspring bears to its parents,
both male and female ; the transmission of ingenerate
diseases, idiosyncracies, and discriminative confor-
mations: and, to perplex us the more, it is observed
that these peculiarities do not commonly transcend to
the succeeding generation.

Then again, there is fhe hybridous production to add
to this chain of mysterious facts. We well know that
certain different species of animals will breed together
and that the progeny will partake not only of the phy-
sical characters but of the dispositions of both ; and
the next wonder is, that this hybrid animal is not itself
generate : such is the mule commonly so called. There
are also hare-rabbits, wolf-dogs, fox-dogs, &c. but the
most curious productions of all are the jumarts, the off-
spring of the bull and mare, the ass and cow, and the
bull and she-ass, an account qf which has been ren-
dered byBouRGELAT. Some hybrid animals too have
been known to propagate their kind ; and by fecun-
dating such for several generations from the seed of the
male of the same species, animals have been produced
bearing no resemblance whatever to the race from
which they have originally sprung.

Lastly, I have to make mention of an occurrence
which is calculated to throw a fresh light altogether upon

112 On the Physiology of the Generative Organs.

this department of physiology. It has long been regard-
ed as a physiological axiom, that impregnation is essen-
tially necessary to the production of new beings, and we
have already seen that it is the most prevalent opinion
at the present day that such productions originate with
the female. Refraining however from any comment on
this doctrine I shall give the particulars of the occur-
rence alluded to. It has always been customary with
my father (who has now served thirty years as Ve-
terinary Surgeon in the Artillery) to inspect the abdo-
minal and thoracic cavities in particular of horses
destroyed for glanders. In one of these inspections a
tumor, about twice the size of the testicle itself and
of an oblong ovoid figure, was found four inches behind
the left kidney, suspended by a slender fibrous band
six inches in length. The tumor proved on section
to be composed of a white, dense, fibrous capsule, ap-
proaching in its texture to cartilage, which in some
places exhibited patches of the true osseous character.
Its cavity is divided by septa crossing each other, of the
same fibrous and patchy-osseous composition as the cap-
sule itself, into nine unequal and irregular but perfectly
distinct cysts. One of these cysts contains an ounce
or more of common yellow fat; two others are filled
with substances bearing strong marks of resemblance
to cerebrum and cerebellum ; in two more are contained
two fangless molar teeth, displaying in perfection both
bony part and enamel, and surrounded by unconverted
pulpy matter ; the sixth cyst shows an incisor nearly
perfect ; the seventh lodges a bony structure, an imper-
fect representation of the os maxillare superius together
with its sinus and alveoli ; the eighth contains medullary
matter, and gives growth to a small cuspidatus or

On the Phifsiology of the Generative Organs. 113

tusk : the ninth encloses numerous lono- liolit-trownish
hairs whose roots arc implanted into globules of adipose
substance. Two small arteries were discovered within
the substance of the connecting; band a'oina- to the
tumor ; but these unfortunately were not traced to
their origin. The horse from whom this tumor was
taken was to external appearance a gelding, was seven
years old, and otherwise presented nothing remarkable.

Many years ago Dr. Baillie published in the
Philosophical Transactions the case of a girl who was
not apparently more than 12 or 13 years of age, in
whom the hymen was perfect and the uterus undeve-
loped as it usually is at puberty, the other marks of
which state were also wanting, whose ovarium was
converted into fat, hair, and teeth : tliis girl, he pre-
sumed, could not have received impregnation, and the
case led the Doctor to depart from the received axiom
in physiology and offer a conjecture, that impregnation
was not necessary to such productions. A proposition
that afterwards received corroboration from the discovery
of a tumor containing hair and teeth in Ruych's collec-
tion, which the Doctor informs us, is said by the cele-
brated collector to have been found in a man's stomach.
The veterinary case however above detailed leaves no
doubt of the fact, or in the Doctor's own words (for
he has also published it) " fully establishes the truth
of my opinion." I do not mean to aver that this tumor
might not have been a degenerated or converted testi-
cle ; but whether it was or was not, the production is no
less conclusive evidence in this point of view, and must
be regarded as a phenomenon both singular in its kind
and inexplicable in its origin.

PART III.

LEC'i URE LX.

On Castiation.

The lustful propensities of the stonehorse and his
intractability under such influence have long rendered
the practice of castration general in this country, where
horses are in the habit of being stabled together and
where the use made of them is such that they have fre-
quent intercourse with one another. The stonehorse
is in many respects an animal of exalted condition
when compared with the gelding : his noble crest, the
richness of his coat, his general gracefulness of form,
his majestic and animated action, his tuneful and
deep-sounding neigh, his hardihood, his vigor and
incurbable mettle at the sight of the object of his
appetence, all proclaim him to be in courage, constitu-
tion, and stamina, a superior animal to the compara-
tively mild, docile, and tractable gelding. Superiorities
of a similar description are evinced by the bull over
the ox, the ram over the wether, the boar over the
barrow ; but these entire males manifest in the season
of concupiscence a formidable ferocity and intolerance
of approach that we are not accustomed to see in the
stonehouse, and which oftentimes render the manage-

On Casiration.

115

ment of them rather a perilous undertaking. But there
are animals in which certain of these qualifications
seem to be reversed, among which the geldings appear
to enjoy the advantages of greater corporeal deve-
lopment ; for after emasculation they are found to
grow to an enormous size, to far surpass both in stature
and bulk the uncastrated males : of this nature are the
rabbit and capon in particular. Even these animals
however are inferior to the perfect males in energy and
spirit, and turn out to be comparatively meek and
hannless creatures. Before attempting to unriddle
these facts I shall bring forward one other which will
go some way to reconcile their apparently contradictory
results ; and that is, that animals who are castrated
prior to the age of puberty grow to a large size, but
that after secretion has begun in the gland such effects
are considerably less marked. Now, two explanations
are offered in solution of these phenomena. It is said,
that the influence this secretion is seen to have on the
nervous system, and the vital energy expended in its
production, will sufficiently account for the unequal
growth and development of the body. There is no
proof however of this consumption of material in the
seminal secretion, and though it were allowed to be
true, still, as the secretion at the early period of life is
not commonly expended but, we believe, absorbed, no
loss would thereby be sustained : indeed, there seem to
be some reasons for believing that these effects are
ascribable to the absorption of semen into the system,
as I hinted before in speaking of the physiology of
generation.

The common practice with breeders in this country
is to have their colts cut as 8090 as the stones can be

I 2

116 On Castration.

felt at the bottom of the purse, which can generally be
done about the expiration of the first year ; though
there are veterinary writers who inform us, that castra-
tion is sometimes performed at three months : I should
apprehend that the operation must prove an arduous
one, and a perilous one too, because the testicles at
this early period are, as we full well know, within the
cavity of the abdomen. Occasional exceptions are made
by breeders to this rule of cutting early, where particu-
lar individuals are defective about the crest and are
of sufficient value to pay for this superadded chance of
improvement. The hope is certainly not ill-founded ;
but it is too much, as is too commonly the case, to
expect its fulfilment in the course of the following year ;
for, if the characteristic features of the stonehorse are
referable to the absorption of semen, how can we reason-
ably look for their development before there is any
sperm secreted ?

The operation of castration in itself is one the suc-
cessful performance of which gains us but little credit
though its unfortunate issue may irretrievably lose a
man his professional reputation. Why the scales
should be so unequally and unfairly balanced is a ques-
tion I will leave to those persons to decide who mete
out praise and censure with characteristic arbitrariness
and inconsideration, and who would heartlessly blast
the professional name of a man because a favorite colt
happened to sink under his knife, though that knife
were handled never so dexterously, as if they them-
selves were all publicans in the temple and unsearch-
able and infallible in their undertakings ! No man of
liberal ideas and sentiments would think of attachino^
blame to a medical practitioner unless he had good

On Castration.

117

reasons for believing that professional ignorance or
inattention had occasioned the grievance ; and no prac-
titioner who is thoroughly master of his art and is con-
scious of having done his duty, has any reason for
listening one moment to the reproach of his employer
when that reproach is given vent to without either
reason or reflection. What has not a little auo-mented
this evil, is, that there are men existing in diminished
numbers denominated gelders, who will take upon them-
selves the accomplishment of the operation at a small
premium, and with whom the attached responsibility is
an affair of little or no consideration, since they are
callous to all conscientious feelings, and enjoy a cele-
brity of too itinerant a nature to be injured by any
local misdemeanor. Some of these gelders certainly
operate with considerable adroitness ; but this need not
excite our surprise when we hear of the great practice
they have, a practice exclusively confined to castration,
not only of horses but of domestic cattle in general ;
watch them however when any thing happens contrary
to the ordinary course of events, either during the ope-
ration or subsequent to it, and they will be seen con-
founded, at a loss what step to take, or flying at
random to expedients and rapidly sacrificing at the
shrine of ignorance a life that would have been per-
fectly safe had it been intrusted to the hands of one
acquainted with the rationale of his proceedings.

The object we have in view in the emasculation of
horses is not to deprive the animal of the procreative
faculty so much as to render him insusceptible of sex-
ual excitement ; though to accomplish the one we must
naturally effect the other. Two operations are in prac-
tice for this purpose. One consists in so disorganizing

118

On Castration.

the secretory structure of the testis that no semen can
be ever afterwards secreted; the other in extirpating
the gland : it has indeed been proposed to intercept
the supply of blood by tying the spermatic arteries,
but I have understood that this will not incapacitate
the animal from experiencing amorous desires. A wri-
ter on castration in the human subject says, ** the
effect on the physical constitution of man is the same,
whether the testicles be injured by contusion so as to
break down their natural texture ; whether the spermatic
vessels be obliterated, leaving the testicles entire ; or
whether these organs be wholly removed by excision."

Before any operation be undertaken, particularly on
horses who have passed the adult period, and more
especially on such as have hunted or raced, it is a
proper precaution to examine the scrotum in the erect
posture in order to ascertain that it be free from her-
nia ; for its presence is by no means an uncommon
occurrence, at the same time it is one that ought to
make us pause before we come to a determination to
operate, if not deter us altogether from the operation.
In several such cases the intestine has presented itself
on the vaginal cavity being laid open, and this has
been followed by such volumes of gut as to baffle all
efforts to restrain or return them ; for, soon after the
escape of intestines, they become distended with air,
red and turgid with blood from constriction at the ring,
and these consequences would end in mortification did
not humanity prompt the destruction of the animal
before his sufferings experienced such dreadful aggra-
vation. When manipulation proves unavailing in such
a case, aided by the liberation of the contained air by
puncturing the bowel with a pin, should that be deemed

On Castration. 119

advisable, Professor Coleman proposes to make an
opening into the belly, near the umbilicus, large enough
to admit the hand, and through its introduction to
draw in the protruded guts ; were I in such an unfor-
tunate dilemma however, I think I should perfer dilat-
ing the abdominal ring, the scrotal opening too if
necessary, proceeding in fact as I would in operating
for hernia. Should we succeed in replacing the bowels
we are to give up all thoughts of extracting the tes-
ticle ; for, when we have strongly united the lips of
the external wound by the quill suture we shall find
that the testicle will materially assist in blocking up
the passage and preventing the descent of the bowel.

The season of the year, should the operator not be
confined to any particular time, is also to be taken into
consideration. I would not operate during the season
of changing the coat, nor even just prior to that period,
for fear of interrupting the process or checking it
altogether ; neither would I choose frosty nor sultry
weather ; but above all it is advisable to suspend the
operation when the flies abound. If the subject have
passed the colt period of age 1 would recommend a
dose of aperient medicine before the operation be under-
taken, unless he should be already living on green food
and then this preparative is unnecessary. He may
also be kept fasting the night before.

The operation, as I stated before, has for its ra-
tionale the incapacitation of amorous excitability, and
this object may be carried into execution, by effecting a
permanent cessation of the secretory functions of the tes-
ticle or by the entire extirpation of the gland . The prac-
tice in some parts of the Continent is to place the testicle
between two hard substances and bruise it in such

120

On Castration.

manner and degree as to destroy its texture ; at least,
this is the object of the bruiser, though the veritable
effect is to excite inflammation which commonly ends
in the effusion of adhesive matter and ultimately con-
verts the glandular structure into a shrinking mass of
callus or schirrus. I should be under apprehensions
myself however of the supervention in some of these
cases of a suppurative or even a gangrenous termina-
tion, and of an accompanying peritonitis or febrile com-
motion of system that might end fatally.

I have heard of excising the epididymes without the
testicles, and portions of the vasa deferentia with them.
There can be no doubt but that the operation would be
followed by a loss of the faculty of procreation ; but
the question to us is, will it reduce the animal to a
state of imbecility or placability ? because, unless it
have such an effect it will not answer our purpose.

Various modes have been put into practice of remov-
ing the testicles. The simplest, and I may add the
barbarous one, is that of tearing them out. The stone
is first laid bare by incision, then firmly grasped by the
hand and torn from the bag. In young animals this
operation is not found to be followed by any hemorrhage
of consequence : the cord is the part that ruptures,
and the lacerated arteries retract within its fringed
ends and become plugged with coagulum until they are
sealed in the ordinary way by effusion. Lambs, pigs,
rabbits, fowls, and other young or small animals, and I
understand in some parts of the country yearling colts,
are thus castrated. Professor Coleman has seen this
operation (which may be literally called extraction)
tried on an old stallion with success : one testicle was
torn out without any subsequent alarming hemorrhage ;

On Castration.

121

and after the lapse of a few days the other was ex-
tracted : had both cords been ruptured in the first
instance, for obvious reasons fatal hemorrhages are
likely to have ensued.

Excision has been practised : the same operation that
is performed on the human subject. An incision is ex-
tended from the abdominal ring nearly to the bottom
of the scrotum, in a line with the cord, which is thereby
laid bare. The cord is then freed from its surrounding
connections, and a ligature carried through it between
the vas deferens and the blood-vessels so as to include
only the latter, and tied with sufficient force to stop
the circulation. Next, the cord is divided half-an-inch
below ^e ligature ; and lastly, the testicle is dissected
out of its cellular bed. The lips of the external w^ounds
are brought together by suture, and the ligatures upon
the cords are suffered to hang out between the stitches.
The chief objection to this mode of castration in horses
is their disposition under such circumstances to perito-
nitis, which arises from the abdominal ring remaining
open : inflammation is readily propagated along the
cord, from the scrotum into the abdomen, and it ap-
pears more likely to follow the application of ligature
than that either of the potential or actual cautery.

Before I enter on the consideration of the mode of
extirpation generally adopted in this country I shall
give some instructions for managing, casting, and fetter-
ing the subject for the operation. Let us take by way of
example a colt that not only remains up to this time un-
broke but one that has not hitherto been haltered. The
first thing to be accomphshed is to contrive to slip upon
his head a flat hempen halter, with which it is advis-
able, should he prove very refractory, to tie him up for
a time that he may hiive an opportunity of abating his

122

On Castration.

repugnant spirit by hanging back and tugging at the
halter : in some instances it proves an excellent quie-
tus to fatigue him by lunging in a fallow field or upon a
dunghill. As soon as he has become tranquil or sullen
enough to bear approach, an attempt may be made to
put a twitch around his nose or his ear ; not however
that this is always necessary or even recommendable,
for I have known colts prove more manageable without
any such check. Having led him to the place where we
intend to cast him it becomes a question with what
means we are provided for this purpose. If we have
hobbles and we can manage to put them on, they are
certainly the preferable means of security ; and the best
mode of using them is this — Cast the horse in the ordi-
nary way, and turn him when cast upon his off side ;
then pass round the near hind cannon a piece of broad
web made for the purpose, or, if that be not at hand,
the hobble of a side-line, and having released it from
the hobble connecting it with the other legs, slip the
web into the heel, and draw the foot forward and con-
fine it against the shoulder by passing the web or rope
around the neck and a second time around the leg or
through the ring of the hobble, after which the web or
rope may be made fast, though it is the safer practice to
have it held by ttvo men : one man will be strong enough
to maintain the extension of the other three legs. A
fourth man will be required at the head, whose duty,
the moment the animal is cast, is to place his knee
upon the neck so as to cushion it in the hollow behind
the ear ; at the same time he ought to raise the nose
with the halter from the ground in order to prevent ob-
struction of the nostrils, and every time the animal
struggles force the head backward, which he will find
will add considerably to his counteractive power in

On Castration. 123

keepiug it from rising. But it may so happen that hob-
bles are not obtainable, or that they cannot be buckled
round the legs of a wild and unruly colt : what is to be
done in either of these cases ? A rope is to be provided
about thirty yards in length and two inches in diameter
— a cart rope will answer the purpose very well and can
generally be procured ; this is to be equally doubled
and formed in the middle by a double knot into a loop
sufficiently large to admit the head through and hang
upon the neck and shoulders with the knot turned
downward after the manner of a harness-collar. The
two ends of the rope coming from the knot in front of
the breast are then to be passed between the fore legs,
extended obliquely backward, carried round the hind
fetlocks within the hollows of the heels, brought for-
ward again on the outside, passed under the collar rope,
and a second time carried backward on the outward
side of. all, and extended to its full length in a direct
line behind the animal : having thus fettered him it
will be found that his hind feet may be drawn un-
der him towards his elbows with the advantages of a
double pulley. Prior to the pull being made it is a good
preparative to place his hind feet, if we dare venture to
handle them, in advance, so that less work may re-
main to be done by force. Two pullers are required
for each rope, and the men ought to be stationed di-
rectly behind the colt as near as convenient to his
quarters, it being now impossible for him to kick ; and
in pulling they ought to exert themselves all at once,
and no less forcibly and simultaneously than suddenly,
so as to take the animal by surprise : this will prevent
much retrocession. The moment the animal is thrown
the man at the head must knee it down in the manner

124

0?i Castration.

afore-described, while the pullers are continuing to haul
the legs forward : when the feet are drawn near
to the elbows the pull must be steadily maintained
until the rope has been twisted once or twice more
round the fetlock ; one rope is then to be carried back-
ward, the other forward, and both are to be firmly
kept by assistants in a state of extension. The colt
may now be turned upon his back and propped in that
position by a bundle of straw placed against either side
of the body. Thus will every facility and perfect safety
be afforded to the operator.

A part of the old practice consists, as a preliminary
to the operation, in unsheathing and drawing out the
penis in order to cleanse it and afterwards lubricate it
with oil or lard ; the end proposed in doing which is,
I have a notion, to render the protraction of the organ
more facile to the animal in the event of much subse-
quent tumefaction : if I be right in my rationale all I
shall remark about the preparative is, that I doubt the
fact aijd consequently cannot reasonably be expected to
become an adopter of the practice.

The first step the operator takes, after having pro-
vided and conveniently arranged his instruments and
whatever else he may be likely to require in the course
of the operation, is to place himself immediately be-
hind the animal and proceed to handle the scrotum in
search of one of the testicles ; for, strange as it may
seem to one who has not been in the routine of such
practice, in consequence of the testicles not having
completed their descent, the power the cremaster has
over them, and their irritability at early age, it often
happens that they are not very readily found, and when
found with some difficulty retained within the imper-

On Castration.

125

feet grasp of the hand : should this prove to be the
case the operator may include the testicle together with
the skin covering it betw^een the clams*, taking care
however not to make use of more compression with the
clams than is necessary simply to prevent its escape.
The scrotum is now to be laid open by extending a lon-
gitudinal incision in the course of the inferior border of
the testicle from its anterior to its posterior end ; which
incision may be made either with a scalpel or the actual
cautery : those who use the knife aver that less inflam-
mation ensues ; those who employ the iron affirm that
this increase of inflammation is more than compensated
for by the opening remaining longer unclosed, and by
the suppression of some trickling hemorrhage which is
apt to confuse the progress of the operator. It is not a
point of great importance ; but, for my own part, I de-
cide it in favor of the knife. Should the first incision
have not penetrated the tunica vaginalis, this mem-
brane is now to be divided in the same manner as the
skin has been ; this is no sooner done than the testicle
springs from its sac, an event commonly announced by
a violent struggle, during which the cremaster exerts its
utmost to withdraw the testicle : of this circumstance
the operator should be aware, for, unless his grasp or
clams be firmly maintained at the moment, the testicle
will escape and recede to the ring ; and this is a slip
that not only evinces a want of foresight and dexterity
on the part of the operator, but is attended probably
with considerable inconvenience and protraction in the
operation. Not however by any means that the operator
is to make any active opposition to this convulsive ef-
fort ; his duty is firmly to maintain his hold and keep up

* The clams in common use have not sufficient curvaUue.

126

On Castration.

a steady and obstinate resistance, patiently awaiting the
remission of the struggle which will be followed by relax-
ation of the cremaster and will give him the entire com-
mand of the testicle. This over, the clams (which may
or may not have been preparatively lapped with a broad
skein of fine tow) are to be applied upon the naked cord ;
but they are not to be closed for compression until tlie
vas deferens has been divided and liberated from their
teeth, a precaution that will save the poor brute a great
deal of suffering, and therefore one, I feel convinced, I
have no occasion to inforce on any other grounds, though
I might do so on the principle of its admitting a more
effectual compression of the blood-vessels. Also, before
the clams are finally closed the place of section of the
cord must be determined. No invariable rule of direc-
tion can be given for this : if it be left too long it is apt
to hang out of the wound afterwards and retard the
process of union ; indeed I have known the end of it
swell into a fungous excrescence which greatly embar-
rassed the practitioner to destroy ; on the other hand, if
it be cut veiy short and the arteries happen to bleed
afresh after it has been released from the clams, the
operator will find it no easy task to recover it from the
retraction of the cremaster. The natural length of the
cord, which will mainly depend on the degree of de-
scent of the gland, is our only guide. Having marked
the place of section, the clams are to be shut sufficiently
close to stop the circulation and hold the cord between
their teeth without any risk of its slipping : at this time
they may be fastened or riot as it happens to suit the
convenience of the operator.

The actual cautery employed may be either the coitt-
mon firing iron with rather a sharper edge than is re-
quired for ordinaiy firing, or it may be an iron with a

On Castration.

V27

straight instead of a curved edge and made additionally
thick at the back in order to retain the heat longer : I
have been in the habit of operating with the former my-
self, and I must confess I do not see any reason for
changing it. The cautery should be heated to that de-
gree at which it begins to turn red ; irons in general in
veterinary practice are used too hot, the common notion
being the hotter the iron the greater the benefit con-
ferred by it : a farrier's aphorism which the sooner we
get rid of the better. The cauterization is to be made
about three quarters of an inch from the surface of the
clams ; for, should secondaiy hemorrhage ensue, this
spare piece of cord will be found particularly service-
able ; but the cord is not to be severed by one continued
application of the iron, no ! reiterated searings are to
be made with a quick sawing movement of the hand,
and not twice together precisely in the same place unless
hemorrhage require it, so as to leave the cord, when
it is completely divided, with a fringe-like extremity :
the withdrawment and re-application of the cautery
must be regulated by the smoke arising from the sear-
ing, which may from time to time be puffed away by
the operator. When the testicle has been removed,
providing there be no bleeding, the clams may be very
cautiously and slowly opened in order to ascertain whe-
ther the hemorrhage be completely staunched or not ;
should it not be, the places of eruption are to be seared
again, and may be so with a fresh heated iron, or the
heel of the one in use ,• but, if the bleeding be already
effectually suppressed surely there can be no good rea-
son for the re-application of the cautery, a practice
much too prevalent, or for subsequently sprinkling and
melting upon the part powdered resin : I deny the as-

128

On Castration.

sumption that this resin renders secondary hemorrhage
less hkely to happen, for reasons I have no time to en-
ter into here, and I consider the practice injurious in as
far as such a brittle asperous material is calculated to
become a source of internal irritation. Should the sper-
matic artery break out repeatedly afresh after several
partial cauterizations, which is every now and then the
case, especially in old subjects, a new surface should
be exposed by shifting the clams a little higher, and
burning off the spare piece of cord : this will submit the
vessel anew to the operation of the iron. As soon as
the hemorrhage appears to be staunched, the cord is not
to be released at the moment, nor all at once, nor care-
lessly : let all remain quiet for a minute or so, squeeze
from a sponge some cold water over the parts, and af-
terwards with slowness and caution dilate the clams so
as to liberate the cord little by little.

The operation concluded, I recommend that the
animal be housed. Turning out afterwards, even sup-
posing that the season, both from the absence of flies
and the congeniality of weather, permit, I am decidedly
averse to : I know very well that it is the practice of
several respectable and experienced veterinary surgeons,
but it is one from which I have witnessed some unto-
ward results and therefore one 1 have reasons for
discountenancing. A roomy, loose, ventilated box in
my humble opinion is the best apartment for him, and
green meat when it can be procured the most suitable
provender ; the surface of his body should be kept
warm ; and a purge may with prospective benefit be
administered to him. For my own part, to speak con-
scientiously,. I believe that the less that is done over
and above this the better for the future welfare of the

Ou Castration. 129

animal ; I know that it is the common practice to
** open the holes" the second day after the operation,
and that there are practitioners who are in the habit of
introducing digestives as they are pleased to consider
them ; and I am perfectly well aware that the slough-
ing extremities of the cords must come away and that if
the openings close immediately after the operation they
cannot be discharged ; but, in reply to all this I say,
that where the iron has been employed the wounds can-
not unite by the first intention, and that they rarely or
never do after the employment of the knife because
they are left unconfined by suture or any means purpose-
ly that they may not. Not that there can be much harm
done in simply breaking down any new adhesions that
may have formed in the openings within the space of
forty-eight hours ; but, what I object to, is, the irresist-
ible -propensity to do something when all is doing that
ought to be doing by the spontaneous operations of the
parts themselves. If a healthy purulent discharge make
its appearance on the second or third day, and the
swelling of the scrotum, extending more or less along
the belly, be moderate, the case may be regarded as
proceeding favorably ; if, on the other hand, there
should be no issue, the parts much and extensively
tumefied, or there be no swelling at all without issue,
pus is most likely confined and requires vent giving to
it by insinuating the finger through the openings and
detaching the lips of the wounds from their surround-
ing adhesions, which may either be caused by some
inspissated blood or other discharge, or be the result of
the adhesive inflammation.

There is yet another operation that has been devised
for removino- the testicles, and one that does not want

PART III. K

130

On Castratio)t.

advocates : I mean that accomplished by means of the
potential cautery. Some years ago certain obscure person
or persons, of whose names I am not advised, obtained
considerable celebrity for this operation, which they
declared surpassed all others in the safety of its per-
formance and the little subsequent inconvenience and
pain experienced by the animal. The caustic they used
was, and, for aught I know, remains a secret : one
however has been experimented of late years and ap-
pears to answer the end extremely well. The usual
method of operating is this —

Provide four fluted pieces of wood, each about four
inches in length : four such pieces of elder from which
the pith has been scooped, about half an inch in dia-
meter, will completely answer the purpose. Fill the
channels of them with a paste composed of oxymuriate
of mercury finely pulverised and mucilage or any soft,
mouldable, adhesive substance that will not affect the
virtue of the caustic ; and afterwards fasten the ends
of them together in pairs so that they may be opened
and shut to a certain limit like a pair of clams. This
done, the animal is to be cast and secured in the ordi-
nary manner, the testicle bared, and a pair of these
caustic clams applied upon the cord at the determined
place of section, in the same manner in which the
metal clams are put on ; after which the loose ends are
to be brought together and tied with force enouo;h to
compress the blood-vessels of the cord and prevent the
clams from slipping. The other cord being similarly
served, both testicles are left dangling out of the scro-
tum, which is prevented from descending over them by
the sticks, and the animal is suffered to rise. In this
condition he is turned loose into a box. Twenty-four

On Castratioti. 131

hours afterwards the testicles are to be amputated with
a common scalpel below the clams, and the clams to
be taken away. The parts are left then much in
the same state as after the application of the actual
cautery ; I therefore need not say anything about after-
treatment.

This operation is said to be followed by less inflam-
mation and its consequences, swelling and discharge,
and they to be of shorter duration, than what are pro-
duced by the actual cautery ; and for this reason to be
safer in its result and particularly recommendable for
stallions who have arrived at or passed the adult period :
it is one that I have not practised myself, but I have
this report of it from unquestionable authority. I once
made a similar experiment with potassa fusa and soft
soap on an ass. On feeling the testicle an hour after-
wards, for only one was experimented on, it dropped
into my hand, and the animal died on the fifth day
following of peritonitis.

K 2

LECTURE LXI.

On the Eye.

We have now the pleasing task before us of inquir-
ing into the conformation and texture of that curious
organ to which the animal owes the extraordinary fa-
culty called vision. The parts constftuting the visual
apparatus being both numerous and various, I shall
make a classification of them into those parts immedi-
ately concerned in the production of vision, and those
which are but auxiliary to the function ; in other words,
into the eyeball and its appendages.

The Appendages.

Regarding their several offices in a general view
it will be found that the eyeball was furnished with the
parts I am about to describe for the purposes of protec-
tion, motion, and abstersion ; so that, as we shall discover
in the course of our investigations, though no one of
them can be taken away without manifest damage to
the organ, they are but accessary not absolutely neces-
sary to the operation of vision.

In viewing the exterior of the eye in man what
characteristically attracts notice is the supercilium

The Appendages, 133

or ei/ebrow, that ornamental arched eminence, clothed
with hair, upon the superciliary ridge of the frontal
bone, which forms so striking a feature and marks such
expression in the human countenance, while it serves
as a shade to protect the eye from descending glares of
light and from foreign bodies coming in the same
direction. Although eyebrows are not allowed to the
horse by veterinary writers, the elevations formed by
the orbital processes of the frontal bones have similar
relation to the eyes to what the same parts have in
man ; and these eminences in addition to their common
pilous coverings are furnished with many long hairs,
which, though they are rather stragglingly planted, for
the most part slant outward and are disposed in arches :
call them therefore by what name we may, they are
evidently designed to intercept vivid rays and foriegn
matters descending upon the eye.

The PALPEBR.ii or eijelids are those moveable cur-
tains in front of the eye that occupy the space compre-
hended within the circular ridge of the orbit. There
are two of them : — an upper and a lower /id. The
upper bemg much the larger and more moveable one,
will cover a proportionably broader segment of the eye-
ball. Both being capable of retraction and expansion
we find them in the former or ordinary state, particu-
larly the upper, drawn into wrinkles which run in
curves and have some effect in the expression of the
eye : in general these wrinkles are more strongly
marked in old horses. The lids are separated by a
transverse aperture or slit, at the extremities of which
they have angular junctions denominated the carithi or
a?ig/es of the eye: the superior or temporal angle is
sharp, is situated in respect to the other in the direc-

134 The Appendages.

tion of an oblique line drawn upward and inclined
outward, and has a loose and moveable attachment to
the tarsal ligament ; the inferior angle is extended and
rounded off, and is firmly fixed to the tendon of the
orbicularis. The palpebral aperture exposes more or less
of the eye in different animals and individuals : in
man and in the pig much of the white of the eye is
seen ; but in the horse and in quadrupeds in general
the transparent part only is exposed, unless when the
eye happens to be turned to one side. The diameter
of this opening will also account for the impression
made upon us that one individual has a large or full
eye, another a small or sunk eye ; for I believe that the
magnitude of the eyeball itself will be found to vary
but inconsiderably, or not sufficiently to explain this
apparent diversity. The loose portion of integument
entering into the composition of the upper lid is pro-
longed from the skin covering the forehead ; that of
the lower lid is derived from the face. Many short
horse-hairs, but not more than three or four long ones,
are planted into the upper lid, growing in the same
direction as those upon the orbital prominence above ;
but from the lower lid stand erect six or seven hairs of
considerable length, having no regular arrangement,
which appear to be stationed there as sentinels to'
give the alarm to the organ of approaching danger ;
for, if by any accident one of them be touched by an
insect or any foreign body in its way to the eye, the
lids are thrown involuntarily into a convulsive twinkle
with such alertness as almost for a certainty to shield
the organ from impingement. The internal surfaces of
the lids are shaped into regular concaves to adapt thcni
to the globe of the eye with which they are everywhere

The Appendages. 135

in exact appositiorr. They are lined by the conjunctive
membrane. The hems of the lids, the ciliary borders
as they are called, are considerably firmer and some-
thing thicker than other parts, but this augmented
thickness diminishes towards the temporal angle : they
limit our view of the eyeball, across which the upper
border swells into a curve, while the lower proceeds
nearly in a straight line. Each of these borders has
two facings or margins : the anterior margin is set with
a row of horse-hairs denominated eyelashes ; the posterior
is hairless and smooth, broadens as it approaches the
inferior canthus, and slopes a little inward in such
manner that when the lids are closed a triangular-
shaped conduit is formed by their approximation, by
which the tears are conducted into the piincta. The
edge of the lid, the boundary line between the two mar-
gins, presents a series of pinholes, which are the orifices
of the ciliary glands: they give issue to a sebaceous
secretion that serves to prevent adhesion of the lids
during sleep, also the escape of the tears as they run
along the triangular canal.

The cilia or eyelashes are those long, fine-pointed
horse-hairs growing from the anterior margins of the lids.
They are generally black, unequal in their lengths, and
are implanted in ranks, two, three, and four deep.
They are much longer and their ranks are more regular
in the upper than in the lower lid : in the former they
grow thin and are discontinued altogether towards the
upper canthus ; in the latter the same thing happens
in approaching the lower canthus. Now, it requires
but little discrimination to perceive that this is the
most advantageous arrangement they could have in
both lids : it is obvious from the position of the head

136 The Appendages.

that light coming from above will dart upon the tem-
ple, while that which is reflected from the ground will
be directed to the nasal canthus ; consequently, the
cilia are suitably disposed to intercept rays in either
direction.

The eyelids in composition are cuticular, muscular,
cartilaginous, and membranous ; also, I may add,
glandular, vascular, and nervous. These several parts
and textures are most developed in the upper lid. The
skin covering and composing the lids, is thin, fine, soft,
and very extensible in its texture ; it becomes more
attenuated as it approaches the ciliary borders, around
which, to a broader extent in the lower lid, it is desti-
tute of hair. This marginal portion, which is com-
monly black, in some horses pied, is pierced by the
eyelashes, perforated by the! ciliary holes, and turns in
to join the conjunctive membrane from which it can
only be distinguished along the line of union by their
respective colors.

The orbicularis palpebrarum consists of a broad sub-
cutaneous stratum of fleshy fibres encircling the lids,
which are most numerous and strongest in the lower
lid and around the inferior angle. These fibres are
attached to, indeed they may be said to arise from,
through the medium of a dense firm substratum of cel-
lular texture, the bones forming the rim of the orbit ;
they have also an origin from a little ligament at the
inferior angle which attaches the caruncle there to the
OS nasi. Around the superior angle the fibres coming
from above decussate those that are ascending. They
are extensively inserted by cellular tissue into the skin
of the fids around their borders. The use of the orbi-
cularis is to approximate or shut the eyelids ; and if it

Th(t Appendages. 137

do this forcibly it will at the same time throw them
into wrinkles : its action is most manifest on the
upper lid. Although this is the only muscle employed
in the closure of the lids it does not appear to be in
action during sleep ; in that state it seems that the
lower lid is perfectly stationary, and that the upper
slides into apposition with it from a natural tendency,
referable to elasticity and conformation, which it has so
to do when it is released from the action of the leva-
tores, the same as what we see happen when those
muscles are paralysed. Similar reasoning appears to
apply to dormant animals, at least the length of time
they continue asleep seems to favor it ; for it is contrary
to analogy and unphysiological to suppose, that the
orbicularis, which at other times is seen only to be
roused by volition or excitement to the eye, should
maintain its action, and for such a duration, after both
these stimuli have been withdrawn. In voluntary
action the lower lid is seen to be raised a little to meet
the other ; but it recedes afterwards by its own elasti-
city. The fibres are so disposed at the nasal angle that
in action they will also compress the lachrymal sac.

Underneath this muscle is found a dense, tough,
Jibrous expansion ; and interposed between the two is a
long, loose, cellular tissue which admits of very free
motion between them. This fibrous substance is the ex-
panded tendon of the levator palpehrce superioris : a mus-
cle that will be described hereafter. It may be traced
completely over the tarsal cartilages ; indeed we only
lose sight of it when we come to the border of the lid.

The tarsus or tarsal cartilages are the substances im-
parting the firmness of feel and the elasticity to the
borders of the lids which I have already had occasion

138 The Appendages.

to notice. There are two of them, a superior and an
inferior: the superior tarsus is the broader and more
convex cartilage ; indeed they correspond nearly in
shape and size to their respective lids. They are con-
vex outwardly; concave, to clasp the eye, inwardly.
They have thick and firm ciliary margins, but grow
thin as they recede from the borders of the lids and end
in fibrous expansions which connect them to the rim of
the orbit, and hence have got the name of the tarsal
ligaments. The tarsus is fibro-cartilaginous in texture ;
but it is so intimately united with the tendon of the
levator and beset with the ducts of the ciliary glands
that it can scarcely be said to be demonstrable in a
separate and perfect state : in short, th& tarsi are the
flexible shapes upon which the other soft parts are
stretched, preserving by their elasticity the form of the
lids, keeping them in constant apposition with the
eyeball, and serving to approximate them when not
counteracted by muscular force. At this stage of the
dissection we gain a view of

The ciliary or Meibomian glands. These are so many,
little, white, follicular bodies, whose canals are large
enough to admit a pin, vertically ranged in parellel
lines like the pipes of an organ along the borders of the
lids, within grooves made for their reception in the
concave part of the tarsal cartilages. They are dis-
tinctly visible when the lids are everted through the
thin lining membrane. They vary somewhat in calibre,
but more in length : they are longer in the upper than
in the lower lid. Viewed through a microscope, each
row, upper and under, is found to consist of a congeries
of very small spheroid bodies, every one of which is
considered to be a distinct gland and to have an excre-

The Appendages. 139

tory duct. They secrete an unctuous or a sebaceous
matter which may be squeezed out from the mouths of
their ducts, the ciliary orijices, in taper portions resem-
bling small white worms. The several textures we have
been examining, including the lining membrane yet to
be described, are all connected together by a fine cellu-
lar tissue entirely destitute of fat : adipose substance
here would not only have proved burdensome and in-
convenient to motion, but by accumulation must inevi-
tably have permanently closed up the eyelids ; the
same as what occasionally happens from serous effu-
sion, to which they are from their loose contexture
particularly permeable.

I'he tunica cotijiinctiva is the membrane which lines
the lids and from them is reflected upon the eyeball :
hence the derivation of the epithet conjunctiva ; it is
also called the tunica adnata from a notion that it arises
from or grows to the globe of the eye. To convey a
familiar notion of its extent and reflections, I may
remark, that if I introduce a probe or my finger be-
tween the lid and the eyeball and attempt to push it to
the back of the orbit, I find that I am suddenly arrested,
and that I cannot effect my purpose, try where I may,
in consequence of meeting with a doubling of con-
junctiva; nay, more ! I find I am unable to touch any
part but what is covered by this membrane. For, after
it has given u complete lining to both the lids, even to
their edges where it is pierced by the ducts of the
Meibomian glands, and" after it has given coverings to
the membrana nictitans, caruncula lachrymalis, and
puncta lachrymalia, it leaves the lids and becomes
reflected upon the globe, to the anterior hemisphere of
which it also gives a complete coating ; so that it is the

140 The. Appendages.

angle of reflection of this membrane that forms the
boundary between the shut and open cavities of the
orbit, between the tangible and intangible parts of the
globe, and that prevents my probe or finger from
reaching the bottom of the eye. Being the common
investmg and connecting membrane of such moveable
parts, we find it running into loose folds in passing from
one part to another, and these folds are furnished with
abundance of cellular tissue. To trace its connections
— along the line of the cilia it forms a union with the
common skin ; in passing backward it adheres closely
to the tarsi, and afterwards has a loose connection with
the tarsal ligaments ; it gives the membrana nictitans
a close covering but is thrown into folds around its
base ; lastly, it adheres but loosely to the opaque cor-
nea but is intimately and inseparably united with the
transparent part : indeed, so perfectly is the membrane
incorporated with the latter that the existence of such
a covering has been doubted ; the continuation however
has obtained of late years the passport of our best
human anatomists, which, with the corroboration of
some remarkable circumstances connected both with
health and disease, appear to have set the question at
rest. The conjunctiva is not thrown into wrinkles as
the skin is when the lids are opened ; the elasticity of
its cellular connections in general, and particularly that
which it has with the adipose matter at the bottom of
the orbit, which from being stretched will recede again,
effectually prevents subsequent corrugation. The con-
junctiva presents two ample surfaces : the adhering
one is rough, lax in texture, and flocculent ; the loose
surface is smooth, glossy, and humid with secretion.
In texture, it is no more than a finer sort of cellular

The Appendages, 141

membrane condensed so as to be rendered firm and re-
sisting-, in which are distributed numerous blood-vessels
that give it a carnation hue. There are some striking-
varieties however in its organization, notwithstanding
it is everywhere one and the same continuous mem-
brane : e. g. the conjunctiva palpebralis possesses
numerous blood-vessels from which, as we know, it
appears commonly red ; the conjunctiva sclerotictE is
comparatively thick and is pulpy in texture, only shows
a straggling red vessel or two, and from the nature
of the part it covers ordinarily appears immaculately
white ; whereas, the conjunctiva corneoe is particularly
thin and dense, and is transparent, and in a perfectly
sound state has no appearance whatever of vascularity ;
indeed, as I said before, vessels were some years ago
denied to it altogether, and their existence probably
would be disputed now did not inflammation of the part
occasionally afford us ocular demonstration of them.

The eyelids receive their vessels from the orbito-
frontal, facial, and temporal arteries. Their veins ter-
minate in the corresponding venous trunks. They
derive their nerves from the fifth pair, and are very
sensible and irritable parts.

Comparing the eye to a window, the lids may be
regarded as the shutters ; their uses being to exclude
light and to protect the organ from all violence or acci-
dent. Light being its natural excitant, exclusion puts
the organ into a state of repose, and enables it to
recruit those energies which intense or long-continued
vision may have weakened or exhausted. During
sleep the lids are closed for this end ; not however
that this is absolutely necessary, for if the nervous
excitability be withheld or suspended, the organ is

142 2%e Appendages.

equally less in a state of repose, as is the case with those
individuals who sleep with their eyes open. Even the
act of winking has a refreshing effect from intercepting
the lio-ht but for an instant.

The membrana nictitans, by farriers called the
haw, is a concavo-convex cartilaginous body, lodged
behind the inferior canthus, between the eyeball and
the side of the orbit. In a perfectly healthy condition
of these parts only the cuticular margin of this sub-
stance is visible, and that preserves the line of the
transparent cornea ; but in a morbid or preternatural
state of sensibility it is protruded forward and en-
croaches more or less upon the transparent part of the
eye. In a detached state it approaches in figure to an
extended triangle, of which the short side is turned
forwards, the lengthened angle backwards. The ante-
rior part is thin, very elastic, and is bounded by a
crescentic edge, terminated by two salient angles, by
which it is shaped to the inward third of the circumfer-
ence of the cornea ; it increases in substance but grows
narrow posteriorly, and there ends in a thick, obtuse,
conical point which is sunk into the adipose substance
at the bottom of the orbit : thus it covers the inner
and inferior side of the globe, about one-third of its
whole superficies. Inwardly, it is evenly concave to
adapt itself to the globe ; outwardly, it is unevenly
convex and clothed with adeps. \yith the exception
of the posterior end, this body is enveloped in con-
junctiva, which, though it adheres closely to the thin,
so loosely invests the thick part that very free and
extensive motion is admitted. The crescentic margin
is edged with cuticle commonly black, sometimes pied,
and this is the only part that is visible externally.

The Appendages. 143

Though it has got the name of a membrana it has a
thin piece of cartilage for its base, to which it owes
its shape : this cartilage is thin and pliant, becomes
thicker and more resisting posteriorly, and is interposed
between two tough brownish substances of a ligament-
ous nature, the outer of which is double the thickness
of the inner.

Writers on comparative anatomy treat of this body as
a third eyelid. In birds it certainly answers this pur-
pose in the ordinary way, and in some quadrupeds too ;
but it appears to have been given to these animals for a
purpose which the lids alone could not accomplish, or
at least not perform with the same ease and effect. If
you make a feint to strike the eye of a horse you will
perceive that the convulsive twinkle of the lids is ac-
companied by the momentary sliding of the membrana
nictitans over the eyeball, the same as a man would op-
pose his arm, or a shield if he had one, to ward off the
blow : in this case therefore it affords greater protection
to the organ than w^hat the lids offer. But its chief
operation appears to be one for which the lids are by no
means well adapted. If a foreign body happens to
lodge in the eye of a man, the lids frequently rather tend
to retain than dislodge it ; and, were it not for his
hands, it would occasionally remain and create dread-
ful irritation : so it would be with a horse were he not
provided with a membrana nictitans, which here serves
him in the place of hands in performing an office to
which the lids in a general way are of themselves inade-
quate. Why was the monkey not furnished with a
membrana nictitans ?^ Because he can make use of
his fore paws after the manner of hands. The eye of a
man therefore, as well as that of a monkey, is, ab-

144 ''//<' Appendages.

stractedly considered, an imperfect organ compared
with the eye of a horse ! What supervenes upon tlie
admission of any insect or foreign substance into the
eye, a rare occurrence among horses, is this — The con-
vulsive twinkle consequent upon the accident commonly
carries the foreign body underneath the lid, where it
soon creates irritation and pain ; tears are then shed in
profusion, and the membrana nictitans during the time
is repeatedly slid across the eye : in one of these efforts
the irritating substance is dislodged from its place, and
in the next probably withdrawn upon the convex part
of the membrane, from which it is subsequently washed
away by the tears. But, as this part has no muscle
whatever in its composition nor any attached to it, how
is it put into motion ? In this manner — The space at
the bottom of the orbit unoccupied by the globe is com-
pletely filled with adeps, the globe therefore cannot be
retracted without displacing some of this fat, that being,
as we well know, liquid in the living subject and conse-
quently incompressible ; and as the globe, when it is
retracted, is drawn with an inclination inward, it is the
fat next the nose or that in which the membrana is cu-
shioned which will give way. It is quite evident what
the result of this must be. The fat is forced against the
membrana, and this moveable substance is projected,
guided by the eyelids and confined by the conjunctiva,
over the transparent cornea, which it more effectually
covers from the circumstance of the globe being at the
same instant turned inward. The retracting muscles re-
laxmg, the adeps from its own inherent elasticity slips
back into its place and draws the membrana nictitans
along with it.

The lachrymal gland. To obtain a full view of

The Appendages. 145

this part in situ the orbital arch must be removed. Un-
derneath this process of bone we find the gland, covered
by the common aponeurotic lining of the orbit, sup-
ported by the eyeball, cushioned upon the levator pal-
pebrse in fat and adipose membrane by which it is con-
fined in its situation. It is a pale, yellowish, delicate
mass, of an irregular figure, moderately convex supe-
riorly in accommodation to the bone, inclining to the
concave inferiorly to adapt it to the globe, of whose
upper and outer surface it occupies the summit. Its
thickest and broadest part is turned forward ; it grows
thin and narrow behind. It is a gland of the conglome-
rate class, being constituted of many lobules, resem-
bling externally those of the salivary glands, connected
together by a delicate and easily lacerable cellular tis-
sue ; and these lobules are themselves composed of
granules, which receive the terminating ramifications
of the supplying arteries ; from the granules also spring
the radicles of the excretory ducts, and they by their
interunion with one another form a set of tubes that open
upon the surface of the conjunctiva lining the upper
lid, not far from the superior angle, by seven distinctly
visible orifices, large enough to admit an eye-probe,
whose margins are marked by slight eminences upon the
conjuctive membrane. The office of this gland is to se-
crete the tears ; and they are conveyed and poured by
its ducts upon the surface of the conjunctiva, where they
become diffused, partly by their own weight and partly
by the motion of the lids, over the transparent part of the
eye. The tears consist of a watery fluid, having a brack-
ish flavour from some saline impregnations they contain,
and from the same cause possessing slightly irritatmg

PART III. L

146 The Appendages.

properties, so that when long or often discharged upon
any bare part they are vei-yapt to occasion excoriation.

The caruncula lachrym alis is a little black or
pied tubercle, whose magnitude varies somewhat in
different horses, lodged within the inferior canthus,
between the eyelids and the eyeball. Only that part of
it is black or pied however which is visible without
disturbing the lids, and this is owing to a covering it
receives from the skin, which turns in for that purpose
at the can thus. Its base is clothed in conjunctiva, and
this is continuous with its cuticular covering. From its
cuticular surface grow several very fine, short hairs. It
is glandular in its composition, being constituted of a
structure which it is said may be resolved into mu-
cous follicles : be this the fact or not, it is found to
yield a mucous matter by expression after death, and it
is not uncommon during life to find a little mucus col-
lected within the canthus. It appears to serve the pur-
pose of directing the tears into the puncta lachrymalia
as they flow against it along the triangular canal.

The puncta lachrymalia are two small circu-
lar holes, large enough to admit the end of a comiAon
silver probe, more distinct in the living than in the
dead subject, one through the inward margin of either
lid near the root of the caruncle. The superior punc-
tum is ordinarily smaller than the inferior, and the lat-
ter is nearer to the caruncle. The puncta are the open-
ings of two little canals, named the lachrymal conduits,
that are formed within the substance of the lids. The
superior of them is somewhat longer than the inferior.

They are both lined with conjunctiva, which assumes
a finer texture at the entrance of the puncta. They

The Appendages. 147

take an oblique direction inward to terminate in the
lachrymal sac; the superior one slanting downward,
the inferior also inclining; a little downward but at the
same time bending forward.

The lachrymal sac is a small membranous bag-
lodged within the funnel-shaped bony hollow that leads
into the canal in the os unguis, behind and rather be-
low the little eminence upon the orbital ridge of that
bone, which forms a very convenient guide to find iU
Our English veterinarians have roundly denied the ex-
istence of this sac ; and such contradictions as the one
here present must exist so long as people will not give
themselves the trouble to look before they venture upon
description. The front of the sac is crossed by the fi-
bres of the orbicularis, which operate in discharging its
contents ; and it has also a connection with the tendon
of that muscle. The posterior part of the sac adheres
firmly to the os unguis. It is composed of a dense^
white, fibrous membrane, and this is furnished with a
lining from the conjunctiva. The sac corresponds
nearly in figure to the funnel-shaped hollow in which it
lies : it is broad and capacious above, where it is j^erfo-
rated by the lachrymal conduits ; but contracted belo\y,
where it is joined to the ductus ad nasum. The inter-
nal surface is uneven, and is lubricated by a mucous
secretion. This sac is the reservoir into which the tears
flow from the lachrymal conduits ; and from which Ihey
are pressed, in the action of winking, into the ductus
ad nasum : gravitation also in the ordinary position of
the head may assist their defluxion.

The ductus ad nasum is a long membranous ca-
pal, beginning from the contracted bottpm of the la-
chrymal sac, running within the bony passage through

L 2

148 The Appendages.

the OS unguis, then along a canal in the os maxillare
superius, between that bone and the os turbinatum an-
terius, to terminate at the inward and inferior part of
the nostril, upon the cuticular surface there, by an
oblique oval orifice, which, from being constantly open,
conspicuously strikes our view whenever we dilate the
nostril. The precaution of its termination upon the
cuticular part was evidently taken to prevent the tears
from trickling upon and irritating the membrane of the
nose. In the first part of its course the duct diminishes
a little in its calibre ; from about its middle however
it begins to enlarge again and soon after acquires its
former diameter. After having emerged from its bony
passages the duct makes several flexures which though
inconsiderable are sufficient to render the introduction
of a probe through it at this part an affair of some
difficulty. The membrane composing the duct appears
to be a continuation of that which lines the sac : in its
passage through the bones it is strengthened by a fi-
brous sheath. Its internal surface is shielded from the
salineness of the tears by a mucous secretion. Its office
is that of conveying away the tears contained within the
sac and of discharging them at the external nostrils.

The tears, as they issue from the ducts of the lachry-
mal gland, are dispersed over the front of the eye, for
the purpose of preserving the transparent part of it
humid and bright, by the operation of winking ; and as
they make their way to the bottom of the eye by gravi-
tation they naturally run along the triangular canal to
the inner canthus and become directed by the caruncu-
la into the puncta, which, it is thought, imbibe them
by some peculiar vital action and not by any supposed
capillary attraction. When the tears overflow their

The Muscles of the Eyeball 1 49

proper channels and trickle down the side of the face,
the eye is said to be watery : this is commonly the con-
dition of the organ on the approach of opthalmia ; it
arises also in states of common mechanical or chemical
irritation ; and in the human subject weeping is in-
duced by excessive pain, and by certain emotions of the
mind, particularly grief. Augmented secretion of tears
may be the effect of inflammatory action in the gland
itself ; but it is more frequently perhaps the result of
sympathy.

The levator PALPEBRiE suPERioRis yet re-
mains to be described. The horse has three muscles
properly belonging to the eyelids : viz. the epicrarnus,
which was put into the cranial region ; the orbicularis ;
and the one now before us. This is a pale, long, slen-
der muscle, spread upon the top of the globe something
after the manner of a fan, within a bed of fat, with the
lachrymal gland above and the sclerotica below it. It
derives its origin from the very bottom of the orbit,
above and rather to the inner side of the four straight mus-
cles of the eyeball, from the inner and upper part of the
foramen opticum, by tendinous adherence. The muscle
broadens from its origin as it proceeds over the globe,
and passing anteriorly between the lachrymal gland and
conjuntiva ends in an aponeurosis which is implanted
into the whole breadth of the border of the lid. Its of-
fice is to elevate the upper eyelid. The act of winking
is rather the effect of alternate relaxation and contrac-
tion of this muscle than of any antagonizing action of
the orbicularis : though I do not mean to deny but that
the latter may slightly assist the operation.

The Muscles of the Eyeball
Are seven in number : four are denominated from

1 50 The M uscles of the Ej/eha it.

their course recti ; two, ohliqiii ; one from its office, re-
tractor. As the straight muscles arise from the same
place, take similar courses, and have corresponding ac-
tions, we may include them all foiir under one descrip-
tion. Their names are the

Rectus Superior vel Levator Oculi,
Rectus Inferior vel Depressor Oculi,
Rectus Externus vel Abductor Oculi,
Rectus Internus vel Addcuctor Oculi.
These muscles are found between the globe and apo-
neurosis of the orbit, concealed by the fat which fills the
interspaces between them. They have contracted ten-
dinous and fleshy origins from the circumferent parts of
the foramen opticum, the optic nerve taking its course
in the midst of them from which they gradually recede
as they approach the eyeball. Diverging a little from
one another in their course, they run at nearly equal dis-
tances in direct lines across the globe to the anterior
part of the tunica sclerotica ; where they are inserted
by short expanded tendons at opposite points into the
globe. The rectus superior will elevate the eyeball ;
the inferior will depress it ; the externus will turn it
outward ; the internus, inward. The simultaneous ac-
tion of all four muscles will retract the globe within the
orbit. The combined action of any two of them con-
tiguous, will turn the globe in an oblique or interme-
diate direction.

The obliquus superior vel Trochlearis traverses
the inner and upper parts of the orbit. It also comes
from the border of the foramen opticum, but it takes
a circuitous course and exceeds any of the recti in
length. It first makes for the inner side of the cavity,
running between the globe and its aponeurosis, where
it passes through a cartilaginous pulley of a particular

The Muscles of the Eyeball, 151

constiuctioii ; it then turns round upon the summit of
the globe, crosses under the tendon of the rectus supe-
rior, and becomes at length inserted into the upper and
outer part of the sclerotica, near to the place of inser-
tion of the rectus externus. It will give the globe a
rotatory motion, in a direction inward and downward.

The obliquus inferior is a shorter muscle and
one probably of more power than the last-described.
It has an oblique situation at the inferior and anterior
part of the orbit. It takes its rise from a little pit in
the OS unguis, behind the lachrymal opening. Its
course is oblique, outward, upward, and backward, and
it thickens in substance as it proceeds. It crosses un-
der the tendon of the rectus inferior and becomes
finally fixed into the under and outer part of the scle-
rotica, close to the junction of the white with the
transparent part of the globe. This muscle will also
give the eyeball a rotatory motion, but in a contrary
direction to the action of the superior oblique. To
illustrate the reciprocal action of the oblique muscles
and its effect on the eye, Mr. Hunter used to direct
a person to look at a windmill when its sails were in
motion. Both acting together they may perhaps ad-
vance the globe a little ; such as appears to be the case
when vision is very staring or earnest, as in fright.

The retractor oculi. In the midst of the
straight muscles, surrounded by fat, at the back of the
globe, we find this, the seventh muscle, one that is
peculiar to animals. It arises from the edge of the
foramen opticum both by tendinous and fleshy fibres.
After this it becomes divisible into four portions, which
are united by cellular tissue, having in the very middle
of them the optic nerve. Its fibres spread outward as

152 The Muscles of the Eyeball

it advances, and are afterwards implanted in an ex-
panded form into the posterior part of the globe, occu-
pying about one-third of the superficial sphere. The
retractor, as its name indicates, will draw the eyeball
backward ; in which operation it will be assisted by
the recti when the four contract altogether. It is this
retraction that puts the membrana nictitans in motion.
The retractive force exertible by the eye is probably
much greater than we suppose it to be : Professor
Coleman in the course of his experimental operations
some years ago for cataract, found himself necessitated
to employ a counteractive force estimated at no less
than 20 lbs. in order to keep the eyeball from receding.
The several divisions of this muscle may act singly also
and thereby co-operate seemingly with any one of the
recti individually.

In addition to the contents of the orbit already
spoken of, viz. the lachrymal gland, the levator palpebrae
superioris, and the seven muscles belonging to the eye-
ball, there are, besides the globe of the eye itself, some
vessels and several important nerves met with there.
There is the optic nerve, sheathed in dura mater, in the
middle, entering at the foramen opticum and penetrat-
ing the back of the globe ; the nerve of the third pair
supplying three of the recti, the inferior oblique, and
the levator palpebrse, besides contributing to the for-
mation of the lenticular ganglion ; the nerve of the
fourth pair running to the trochlearis ; the nerve of the
sixth pair to the rectus externus ; and the opthalmic
artery whose ramifications are distributed to the globe
and the various parts connected with it ; and the op-
thalmic vein also which returns the blood into the
cavernous sinus.

The Muscles of the Ei/ebalL 153

These several parts -are cushioned and packed in an
abundance of soft fat which serves to connect them
together, and at the same time accurately fills up the
interspaces. Being in a state of semi-fluidity during
life this substance readily accommodates itself to the
various movements of the globe, which ordinarily it
bolsters forward in front of the orbit, though it is every
now and then forced to one side and then drives before
it the membrana nictitans. That this is one of its
principal purposes is shown by there being compara-
tively much less of it in man. In cases of extreme
emaciation part of this fat becomes absorbed, producing
that appearance called sunk-eyed.

The orbit is lined with a dense, firm, fibrous sheath,
having the appearance of dura mater, of which it is
said to be a continuation. It has fibrous attachments
to the bony inequalities and foramina at the bottom of
the orbit, and by several threads is fastened to the back
or rough part of the zygomatic arch. It is thickest
and offers most resistance at the outer and upper parts
of the cavity where bony parietes are wanting. It
serves to hold the contained parts together and to pro-
tect them from external injury ; and it offers resistance
to the impulse of the fat whenever the eyeball is
retracted.

LECTURE LXII.

The Eyeball

The ball, globe, bulb, or apple, of the eye, so variously
denominated from its spherical form, may be regarded
as an optical instrument of complex but singularly
beautiful construction into which the rays of light are
received and by which they are in their passage in
such manner refracted and inflected as to be collected
into focal points and thereby to represent a correct
image in miniature of the object from which they are
radiating.

In order that we may perfectly understand the posi-
tion of the eyeball in the head, the manner in which it
is sustained in this position, and the various motions it
is capable of, and thereby form correct ideas of the axis
and range of vision, it is necessary for us to renew our
acquaintance with the orbits. The orbit is an imper-
fect socket formed by unequal pieces of bone coming
from the ossa frontis, malae, unguis, temporis, ethmoi-
des, et sphenoides, in the following manner and pro-
portions— Of the external ridge : the superior and
anterior part, about two-fifths of the whole circumfer-
ence, is formed by the orbital process of the os frontis ;

The Eyehdli, 155

the inferior and anterior part, about one-fifth, by the os
unguis ; and the remaining two-fifths by the ossa raalsc
et temporis, in the ratio of three to one. Internally,
the floor is constituted of the orbital plates of the ossa
unguis et malie ; the side by that of the os frontis and
by the' os planum ; the back parts by the ossa ethmoi-
des et sphenoides. The socket is of an irregular figure :
looking into it in front it has the appearance of being
of a conoid or pyramidal form, but then on examination
we find that the roof and one side are deficient, that
the eyeball is guarded in those places only by bony
arches, which, though they are firmly stayed and well
placed to ward off attacks in the most dangerous direc-
tions, seem to leave the organ exposed in others. This,
however, is far from being the case. In the recent
subject, not only a considerable part of the vacuity be-
hind is occupied by the condyle of the posterior max-
illa, but the remainder of the space, posterior to the
orbital sheath, is filled with adeps : and this serves as
a bulwark to the globe behind, while it freely admits of
the motions of the jaw. But, what principally de-
mands our attention here is the sheath lining the orbit.
We have lately examined this and found it to possess
considerable density, firmness, and resistance, and to
be thickest at the external and superior parts ; and we
now perceive that it was made so because there it has
to supply the place of bone. The socket formed by
the sheath is described by some as conical, by others as
pyramidal ; perhaps it bears the nearest approach to the
latter form, though, like other anatomical comparisons
to geometrical figures, it will be found not to possess
mathematical precision : for, the basis of the pyramid,
instead of being equidistant at every point from the

156 The Eyeball.

apex, is obliquely truncated in a direction outward and
downward ; to which may be added, there is a pro-
minence of the boundary edge next the nose which
contributes with this truncation to give the eye a
sunken appearance on that side, while the outer part
of the globe projects a little beyond the socket. The
orbital ridge has a quadrilateral figure ; the external
side is the longest, the inferior one the shortest, the
vertical to the transverse diameter being in the ratio of
seven to six : the line of the internal side is interrupted
by a notch. The axis of the orbit directs a horizontal
line more outward than forward, more forward than
downward : this line intersects another horizontal line
drawn directly forward at an angle of about 10". and
one drawn directly outward at about 20°. ; the inclina-
tion downward however will of course vary with the
position of the head. The axis of the eyeball is not
exactly that of the orbit, though it also takes a direc-
tion more outward than forward ; for, in the ordinary
position of the head, it is perfectly horizontal, and, in
consequence of the prominence of the eye next the
temple, inclines more forward than the orbital axis,
probably by 10°. : the motions of the eye will in course
vary its axis considerably and especially in the lateral
direction. In fact, the eyes, placed as they are in the
head, command nearly a whole sphere of vision : the
horse therefore is amply provided with visual means for
seeking food and avoiding danger.

The eyeball is placed within the anterior or capacious
part of the orbit, nearer to the frontal than the tempo-
ral side, with a degree of prominence peculiar to the
individual and within certain limits variable at his will.
In front the ball is suspended by the eyelids, laterally

The Coats or Membranex.

and posteriorly it is slung by its seven muscles, and
posteriorly it is also retained by the optic nerve ; which
muscles and nerve, together with its blood-vessels, are,
as we have seen, enveloped in fat ; and this fat forms
a bolster for the globe, as has also been pointed out,
maintaining it in a due state of advancement, and ma-
terially assisting in preserving its proper position and
giving steadiness to its movements.

The magnitude of the globe varies something in
different individuals. Its figure is a compound of two
spheres of different diameters, united in front by an
elliptical line. The small sphere, or rather hemisphere,
projects in front from the large one, and is transparent;
the large sphere, the less imperfect one, is flattened
.posteriorly and prominent around its sides, but is
opaque : the former, from its apparent resemblance to
horn, has been named the cornea, or, to distinguish it
from the latter which is sometimes called the cornea
opaca, the cornea lucida vel transparens. The diameter
of the globe, according to Girard, exceeds its axis
by about a line-and-a-half : (trois millimetres:) this is
the reverse of the relative dimensions of the human eye,
of which the axis exceeds the diameter by nearly a line.

The visual organ is composed — \st. of certain mem-
branous parts, mostly opaque, called coats, investing
and protecting the contents of the globe ; 2ndly. of a
series of diaphanous parts or refracting agents ; ^dly.
of a nervous lining which receives a representation of
the object seen and transmits the impression along the
optic nerve to the sensorium.

The Coats or Membranes
Are, the tunica sclerotica, choroides, retina, cornea,

158 Tke Coats or Membratm.

and the iris. The three first of these membranes form
the opaque case containing the transparent parts, and
are, properly speaking, the coats of the eye, being con-
centrically arranged one within another like the layers
of an onion ; the cornea is the sight of the eye, the
watch-glass, as it were, fitted into this case ; and the
iris is the coloured partition internally between the
light and dark compartments of the organ, with a hole
through its centre by which they communicate.

The tunica sclerotica, so named from its
hardness or firmness, composes the white part of the
globe, extending from the insertion of the optic nerve to
the cornea, and forming about four-fifths of the whole
superficies. Behind, it receives the insertion of the
fleshy fibres of the retractor, and in front it is strengtli-
ened by the implantation of the tendons of the four
reoti, which have been erroneously supposed to expand
over the part covered by conjunctiva and account for
its shining whiteness, whence the expansion has been
named the tunica albuginea ; but, in point of fact, no
such expansion exists, the remarkable whiteness of the
part being referable to the transparent glossiness of the
conjunctiva itself. In other places the surface of the
sclerotica is padded with fat. Its union with the cor-
nea is so neat and perfect that one has been said to be
a continuation of the other ; but the sclerotica mani-
festly differs from the cornea, not only in being opaque,
but in its texture and organization, and also in its
diseases. Moreover, either maceration or putrefaction
disengages one from the other, and then it is demon-
strable that the surrounding margin of the elliptical
opening of the sclerotica is bevelled off for the purpose
of overlapping and nicely fitting the edge of the cornea

The Coats or Memhraues.

159

which is also sloped off, but in the contrary direction.
The sclerotica is thinner upon its nasal than its tem-
poral side, though it terminates in front in a thickened
border all round ; but it is thickest at its posterior part,
near the centre of which is a small round aperture for
the admission of the optic nerve : this opening is situated
towards the inner and inferior part of the globe, and
appears, when examined internally, as a white cribri-
form spot. The internal concave surface of the sclero-
tica is in close contact with the tunica choroides, from
which it commonly receives a dusky stain, the natural
effect of transudation after death : these <Joats are
weakly connected together by a very delicate cellular
tissue, as well as by blood-vessels and nerves which
find their way in great numbers to the choroid coat
through pinholes in the sclerotica most numerous round
about the entrance of the optic nerve and in the vicinity
of the corneal border in front. The sclerotica possesses
this peculiarity over other ocular textures, that it re-
tains its figure in the detached state equally the same
that it does when distended and connected with other
parts, and that it will regain its shape after deformity
or distortion immediately the pressure (should that have
been the agent) is removed ; even femall excised por-
tions manifest the same elastic properties : so far is
this from being the case with the other component parts
of the eyeball, that, we shall find, there is but one of
them but what is directly or indirectly dependent upon
the sclerotica for the preservation of its form, and that
one (the chrystalline lens) is unable to recover itself
after its shape has once been destroyed. Some anato-
mists consider this tunic to be an expansion, either a
laminated or an entire one, of the sheath of the optic

160

The Coats or Membranes.

nerve : whether one or other or neither be the case, we find
their union to be intimate, and continuity of fibre to be
the uniting medium. Its fibres, which are dense, firm,
and elastic, and remarkable for their whiteness, are of
the same nature apparently as those that compose liga-
ments and tendons ; they take every variety of di-
rection, and are so strongly interwoven and matted to-
gether that no force the fingers can exert will lacerate
it : indeed, they are found to decussate so generally
throughout the tunic that the opinion of its being divi-
sible into layers seems to be destitute of anatomical
evidence. The principal use of the sclerotica is to
give configuration, support, and protection to the form-
less and delicate parts encased within it. It also affords
attachment to the muscles moving the globe.

The cornea, also called the transparent cornea, is
the part completing the spherocity of the eyeball in front
by filling up the elliptical vacuity left by the sclerotica,
forming rather more than one-fifth of the whole super-
ficies. In ordinary vision in quadrupeds (not overlook-
ing that notable exception, the hog,) this is the only
visible part of the eye ; they have not therefore, accord-
ing to the common meaning of the term, any white to
their eyes ; at least none is apparent but on such occa-
sions as when the animal, without turning his head,
looks behind him, a glance that generally betokens
slyness, if not viciousness : and this, I imagine, is the
origin of the vulgar assignation of vice to a horse who is
in the habit of shewing the white of his eye. The con-
vexity of the cornea, which varies somewhat in different
individuals, is greater than that of the sclerotica ; it
being, as was said before, the segment of a smaller
sphere let into the segment of a larger one. The figure

The Coats or Membranes. 161

of the circiimferent outline of the cornea is horizontally
elliptical ; not a perfect ellipsis however, for the part
turned inwards is bounded by an arc of larger sweep
than that turned outwards: a remark that will serve us,
so long as we remember that the optic nerve pierces the
inner and inferior part of the globe, to distinguish a
right eyeball from a left in the detached state. The
vertical diameter of the cornea bears the same relative
ratio to its longitudinal that five does to eight. Its
margin is cut aslant to fit that of the sclerotica, by
which it is overlapped ; in this manner the surfaces of
apposition are considerably broadened and their union
so much the more strengthened : indeed, their union
is so firm that as much resistance is opposed to their
mechanical separation as to the laceration of either of
their textures. Its convex surface is covered by con-
junctiva, continued over it from the sclerotica, upon
which its limits are marked by a black elliptical line re-,
lieved by a dusky shade : this part of the membrane how-
ever is so condensed and attenuated that it is perfectly
diaphanous, a circumstance that has given rise to doubt
and even denial of the continuation ; the fact however
is now admitted to receive indubitable evidence after
long protracted maceration. At first view we might su-
spect that the cornea itself, being so pellucid a part, was
thin and delicate in its texture; but, in point of fact,
it approaches in density, firmness, and resistance to
the sclerotica ; for neither one nor the other are we able
to rend with our hands, even with the aid of the forceps.
If an incision be made across the cornea, lamina after
lamina may be stripped off; and while we are doing
this we cannot but notice that the surface is continuaJly
freshly bedewed with a limpid serous fluid oozing from

PART HI. M

162

The Coats or Membrafies'.

the cellular interstices : some suppose that this wateiy
exudation is pent in cells during life, and that its escape
and diffusion after death is the cause of the filmy ob-
scurity of the cornea which so speedily follows the ex-
tinction of life. If the cornea be macerated, it swells,
turns opaque, and becomes soft and flabby, and in this
condition it is very readily separable into its component
laminae, in consequence of their cellular adhesions, which
in the recent eye are dense and compact, being now lax
and filled with fluid ; indeed, the laminse may be felt by
squeezing them between the fingers, sliding one over
another: for all this however we cannot correctly deter-
mine their number, but we can find that the anterior
layer is evidently continued from the conjunctiva scle-
roticae. When closely examined in this state the la-
minae show signs of a fibrous texture ; and the density
and toughness of the cornea favour this idea, as also
does the circumstance of its blood-vessels being both
small and scarce. In the healthy condition they are too
minute to admit red blood, though red vessels are seen
commonly enough in opthalmia. Nerves have not
been traced into its substance, nor do its laminae appear
to be sensible, with the exception of the anterior one,
which has the same feeling as other parts of the con-
junctiva : this is a strong fact to show their identity.
Since, then, this is a part that possesses such firmaess
and mechanical resistance, we must consider that it was
made so tough to complete the eye-case in front ; at the
same time, from being transparent, it is perfectly per-
meable to light, and as such is operative in the pro-
duction of vision.

The iris, so denominated from the brilliancy of its
aspect and the variety of its tints, is that part from the

The Coals or Membranes, lb'3

appearance of which is vulgarly assigned the color of
the eye. In order to examine it we must excise the
cornea, behind which it is extended, like an internal
eyelid, for the purpose of regulating the quantity of
light going to the bottom of the eye. Its terminating
edge being fixed all round just behind the cornea, they
will both have the same figure in outline ; but as the
cornea is concave and the iris flat an interval is left
between them, deepest in the middle, and this is called
the anterior chambevy to distinguish it from another
space behind the iris denominated the 'posterior chamber.
It has a perforation horizontally elliptical through its
middle which forms the pupil, or what is vulgarly called
the sight of the eye : the aperture is rather nearer to the
inner than the outer, to the upper than lower side of
the globe, and this in course is attended with a corre-
sponding variation in the breadth of the iris at these
places. The diameter of the pupil will vary, and so
indeed will its figure occasionally, according to the
condition of the organ and. the quantity of light to
which it is exposed. The outline of the pupil, both
above and below, is interrupted by several, little, black,
pendulous bodies, which are the corpora nigra.

We distinguish in the iris two flat faces, and two
elliptical margins. The anterior face, the veritable iris,
is noted for its brilliancy, and for its color which varies
in different individuals. It is a remarkable fact that
this variety of color of the iris corresponds with that
of the hair : bay and chesnut horses have hazel eyes ;
brown horses have brownish eyes ; and very dark brown
or black horses, eyes of a still darker dusky-brown
shade. This correspondence is also observable in hu-
man eyes, but the diversity of colors of the irides of

M 2

X64 The Coats or Membranes.

men is infinitely greater than what we see among any
one species of animals. Cream-colored and milk-
white horses have wall-eyes ; and Albinos have red
eyes : in both which instances the iris is destitute of
any coloring matter whatever. Both eyes are com-
monly alike in color and shade ; thongh now and then
it happens that one is a light, its fellow a dark eye.
Upon the anterior face are visible two broad elliptical
belts, the inner of which may be distinguished from the
outer by being a little darker-colored ; and upon the
latter are discernible several plicae, of which two are
more elevated and conspicuous than the rest ; the inner
of these two plicae forms the boundary line of the belts,
and casts a shade upon the inner belt that gives its
* surface the effect of distance when viewed in the living
eye. — The posterior face of the iris is covered with a
thick stratum of black mucous matter derived from
the pigment, which, from imparting to it the color of
a grape, has got the part the name of uvea ; and it
would appear that the colour of the iris (the nature
and production of which yet remain a mystery) is
essentially dependent upon the uvea ; for if the pig-
ment be washed off the iris is rendered colorless. In
wall-eyes, in which the uvea is wanting, the iris is white ;
so it is in Albinos, in whose eyes there is the same
deficiency. This surface has likewise a division into
two by a prominent elliptical fold in the middle : the
larger one has numerous convergent striae upon it which
run in radii from the outer margin, where they look
almost like continuations of the ciliary processes, and
terminate in this prominent fold ; the inner and lesser
division is a plane oval surface, apparently without
striae, perforated in the centre by the pupil. The

The Coats or Membranes.

165

greater or ciliari/ margin of the iris is embraced by the
ciliary circle, and has a broad attachment to the choroid
coat besides, through the continuation of the pigmen-
tum nigrum. — The lesser or pupillari/ margin, rendered
black and prominent by an edging from the uvea,
hangs loose and floating in the aqueous humor, con-
stitutes the boundary line of the pupil, and gives at-
tachment to the corpora nigra. — The pupil, then, is
nothing more than a hole in the iris, oblong or elliptical
in the same direction as the cornea, whose diameter
varies w^ith the intensity of the light to which the eye
is exposed. There are animals however in which the
pupil does not ordinarily correspond in figure with the
cornea, in consequence of its varying its relative dimen-
sions as well as its size under such circumstances : ^
e. g. in the cat, the cornea is circular, but the pupil
during the day is elliptical in the vertical direction,
though at night it is circular also ; and, indeed, the
pupil of the horse, widely dilated from amaurosis or the
influence of belladonna, likewise assumes the circular
figure.

All that we know about the structure of the iris, is,
that it is apparently a fibrous membrane divisible into
two layers, which are abundantly pervaded by arteries
and nerves and thickly coated behind with uvea ; and
that this division of it cannot be carried through the
pupillary margin, there its layers becoming inseparable.
Its fibres are believed by some to be muscular, the
quick and free motions of the part forming the princi-
pal grounds of their argument ; for the fibres by their
own admission are too minute to admit of anatomical
demonstration. Professor Coleman found them well
marked in the eye of a greyhound that had been long

1C6 The Coats or Membranes.

inured to cunning coursing in a rabbit warren. Not
only however do these fibres elude all anatomical test
of their nature, but they are insensible to the common
mechanical and chemical excitants of other muscles,
and even to galvanism. — The arteries of the iris come
from the long ciliary, and are arranged so as to form
two circuli arterosi upon its anterior face, corresponding
to the two prominent plicae thereon : from these, minute
branches are detached which are so numerous that
they of themselves appear to constitute the basis or
essential part of its texture. The ciliary nerves lavish
their branches upon the iris, but on account of their
minuteness they defy all attempts to make out their
distribution.

The motions of the iris consist in contraction and
dilatation, and the dimensions of the pupil are con-
versely regulated thereby : when the iris is contracted
the pupil is dilated, and vice versa ; the pupil however
is never shut so completely as to exclude light altoge-
ther. Its motions are involuntary, excited by the pre-
sence of light, and, coeteris paribus, are regulated by
the quantity admitted or the suddenness with which it
is admitted into the eye. This action however is not
the effect of direct stimulus, but is a secondary or
sympathetic result ; for light has no visible operation
on the iris itself, the impression is made upon the
retina: in gutta serena (paralysis of the optic nerve)
the pupil becomes dilated and the iris remains motion-
less ; and when the pupil is closed so that light cannot
get to the bottom of the eye, the pupil is likewise
fixed. Furthermore, the motions of the iris are in-
fluenced by the magnitude and distance of the object
of vision : when the eye is intently viewing a near ob-

The Coats or Membranes.

167

ject or one very small, the pupil becomes contracted ;
but, if the object be removed to a distance, or it have
a wide surface, the pupil becomes dilated. During
sleep the pupil is contracted. After death it remains
in that state, either contracted or dilated, in which it
happened to be at the instant of the last expiration,
and cannot by any means we may employ be re-excited
to action. The efficient cause of these motions remains
undeveloped.

The corpora nigra. I have given this name to
the little, globular, black bodies which are attached
around the pupillary margin of the iris; and I have
done so because I am not aware that any appellation
has been assigned them by the veterinarians of this
country : Girard, speaking of them, says, " que
I'ouverture pupillaire offre communtment quelques tu-
bercles noirs, sortes de prolongemens franges, replies
en dehors, et nommes fungus ; " but the term fungus
sounds to our ears so much like disease that I consider
this a sufficient reason for not adopting it. By this
laconic description of Girard's (for this is ail he says
about them) it would appear that they are not unex-
ceptionably present : I have not myself remarked their
deficiency unless where the pigment was wanting.
There are commonly three of them, about the magni-
tude of peppercorns, ranged eri masse along the upper
margin of the pupil, something nearer to the outer
than the inner comer, and the largest is placed out-
ward-most, unless we reckon a very small one indeed
which is generally found beside it. Along the under
edge there are hkewise three, sometimes four of them,
but they are comparatively inconsiderable, not being
larger than pins' heads. The corpora nigra superiora

168 The Coats or Membranes.

hang more or less over the pupillary opening in fronty
the corpora inferiora project just enough to interrupt
the regularity of the pupillary line. I am inclined to
regard them as productions of the black pigment : they
have similar fringed or velvety surfaces, and appear to
be resolvable into the same mucous substance, and to
be continued from the uvea— to be in fact uveal excres-
cences. Professor Colemam has seen these bodies
as large as the largest garden peas without their t;eem-
ing to interfere at all with vision.

The tunica choroides is the black, soft, deli-
cate texture immediately covered by the sclerotica. It
extends from around the termination of the optic nerve,
by which it is perforated, in accurate contact with the
internal surface of the sclerotica, as far fomard as the
edge of the cornea, where it ends in the ciliary circle :
and the sclerotica and it are connected by a very fine
cellular web, by intercurrent blood-vessels, and by the
ciliary nerves. — If that part of the sclerotica in union
with the cornea be removed, we shall expose, imme-
diately behind the vanishing edge of the latter, a whitish
circular belt about two lines in breadth : this is named
the orbicularis ciliaris, ciliary circle, or ciliary ligament.
It forms the medium of union or line of demarcation
between the choroides and iris ; and this is the place
where the sclerotica has the firmest connection with the
choroides, and through that connection also an inter-
mediate one with the iris. The basis of the ciliary cir-
cle is nothing but condensed cellular membrane ; but
the ciliary vessels and nerves in their course pervade it
and form a sort of vascular and nervous plexus, which
circumstance has given rise to some other names for it.
The ligament may be stripped off' altogether with the

The Coats or Membranes. IGO

forceps ; it adheres however with most tenacity to the
choroides. Fontana has described in the human eye
a triangular canal in the cellular tissue between the
sclerotica and this ligament ; but, for my own part, I
cannot find ar^y such cavity in the eye of the horse. —
The inner surface of the choroides is accurately applied
in every point to the tunic internally placed, the re-
tina ; though so closely applied however they nowhere
adhere, either by vascular or cellular connection. Ex-
ternally, the choroides presents everywhere a black
surface ; internally, only the anterior parts are black,
its posterior concave, about one half of the entire
internal superficies, being of a brilliant variegated green
tint : the black part is called the nigi'um pigmentum ;
the green, the tapetum lucidum. The basis of the
structure of the choroides consists in vascularity : arte-
ries and veins in countless numbers enter into its com-
position, and these are connected together by a fine
cellular tissue. Though this fact has been ascertained
however, the arrangement of the vessels is a question
that does not seem to this day to have been satisfactorily
determined : some being of opinion that there are two
strata or sets of vessels, an external one of veins, which
they call the vena vorticosa, and an internal one of ar-
teries, to which has been given the name of tunica liays-
chiana ; while others place the veins upon the inside.
— Les ai teres," says Gfrabd, " distribuees a la sur-
face exteme forment une couche premiere, unie a une
lame interieure, dans laquelle se rendent les veines."
It is perhaps sufficient for us to know that this tunic is,
with least difficulty in the situation of the tapetum, se-
parable into two layers ; that these layers consist al-
most entirely of blood-vessels, which cross and inter-

17a

I'he Coats or Membranes.

cross one another so as to form a vascular network very
difficult if not impossible to unravel ; and that its arte-
ries come from the ciliary, and its veins pour their blood
into the opthalmic vein. In order to examine the struc-
ture of the choroides it should be freed from the color-
ing matter adhering to it, and this cannot be done with-
out suffering it to remain some days in water which is
very apt to impair its texture. This adventitious sub-
stance is spread over both its surfaces, but the inner
layer is thicker and more consistent and more detennin-
able in its limits and disposition than the outer. The
outer, the entirely black one, the veritable nigrum pig-
mentum, begins just behind the ciliary ligament and
appears to be uniformly continued over the whole of the
posterior hemisphere ; the inner one, partly black and
partly green, lines the dark chamber, fills up the inter-
stices between the ciliary processes, and coats the pos-
terior face of the iris. The colored part, which is called
the tapetum or carpet, or from its brightness the tapetum
LUCiDUM, is not found in the eyes of men, birds, or
fishes, and in quadrupeds it is seen of different colors :
in the horse, it is pea-green ; in the cat, it is yellow ;
in the stag, it is blue. In all however its relative situa-
tion is the same : it makes a circular sweep to a certain
extent around the entrance of the optic nerve ; in the
horse, it spreads wider superiorly than inferiorly, occu-
pying the posterior half of the dark chamber, that part
which is within the axis of vision. In a perfectly fresh
eye, the tapetum is bright and its limits are distinctly
marked ; indeed, with pains, it may be stripped cleanly
off the sclerotica, and even without staining the fingers
in so doing • but putrefaction destroys its verdure and
consistency, and converts the whole pigment into a thin.

The Con ts or Mem b r a ties . Ill

*

sooty, semi-fluid matter, readily diffusible in water, and
which leaves a dusky stain upon the sclerotica and other
parts in contact with it. The pigmentum and tapetum,
apparently the same substance, differing only in color,
are supposed to be a peculiar secretion from the vessels
of the choroides, a secretion of a mucous nature, only
that it is contained within a very fine, soft, and delicate
cellular tissue by which it is held together. Mr. Hun-
ter compared it to the rete mucosum ; and there would
appear not only to be a similarity in composition but
also some mysterious relationship existing between them
in regard to their formation ; for, in Albinos, purely
white and cream-colored horses, white rabbits, ferrets,
&c. in whose eyes the pigment is deficient, the rete
mucosum is also wanting : this accounts for the delicate
whiteness of their skins, and for the redness of their
eyes, in which the blood circulating in the vessels of
the choroid is seen through the pupil unobscured by co-
loring matter. Leaving the ciliary circle, the choroides
makes a sudden inflexion inward behind the iris, and
then turns intensely black ; this inflexion considerably
contracting the space the tunic was formerly spread
over, there results a superabundance of substance, which
we find to be disposed in puckers or plaits, arranged in
parellel lines like radii around the circumference of the
chrystalline lens : regarding the doubling and plaits to-
gether as a whole, the part is named the corpus ciliare ;
but the plaits by themselves are called the processus ci-
liares. These processes behind repose upon the soft
bed of the vitreous humor wherein they make counter-
impressions ; the membranula corona ciliaris (which
will be described hereafter) being interposed. The cor-
pus ciliare is coated with pigment of the blackest dye.

172 The Coats or Membranes.

the interstices of the processes in particular are thickly-
bespread with it : this explains its remarkable black-
ness at this part, and accounts for the radiated circle of
black stri(£ marked upon the surface of the membranula
ciliaris, after the processes have been stripped off. In
order to examine the structure and connexions of the
corpus ciliare the pigment should be washed off; it will
then be found to be continuous at the ciliary circle with
the choroides, to possess the same vascular basis as
that tunic, and in fact in nowise to differ from the cho-
roides but in its disposition and arrangement. The in-
ternal part of the choroides at the place of inflection
presents to minute inspection, or through a magnifying
glass, numerous delicate and faintly-marked stripes,
arranged in parellel radii, which are the ciliary strict ;
and every two or more of these striae unite afterwards to
form a single plait or ciliary process, which runs direct
to the chrystalline lens, growing broader as it proceeds,
adhering in its way to the membranula ciliaris, which
is behind it, and terminating with an angular point
against the capsule of the lens, with which, though in
contact, it has no connection whatever. The best view
we can have of these processes is obtained by making a
perpendicular section of the eye and looking at them
through the remaining portion of vitreous humor : a
broad, black, well-defined line will then be seen, show-
ing their union with the choroides ; and in consequence
of their posterior edges having a greyish cast we are en-
abled to distinguish their interstices filled with black
pigment; they are also seen to vary in length, but not
perceptibly in breadth.

The retina, so called from its supposed reticu-
lated texture, is the third or innermost tunic. The

The Coats or Memhnmes. 173

optic nerve, having reached the inner and inferior
part of the globe, pierces the sclerotic and cho-
roid coats, and in its passage through them grows
somewhat contracted in its diameter : havino- arriv-
ed at the internal part the nerve swells' into a lit-
tle, white, eminent papilla (appearing as a white spot
in the living eye) from whose circumference issues in
white radiating lines a medullary pulp which spreads
over the entire surface of the dark chamber, sus-
tained internally by the vitreous humor, accurately
applied to the choroides externally, but having no ad-
hesions whatever until it bas reached the corpus ciliare.
In an eye perfectly recent and unprepared in any way
for the examination, the retina appears to terminate on
a sudden, by a defined edge, at the black circle upon
the ciliary body, by adhesion there to the tunica vitrea ;
it is asserted however by some anatomists that it does
not end but only grows much thinner here, afterwards
extending almost imperceptibly between the ciliary pro-
cesses and tunica vitrea and proceeding to the capsule
of the lens ; and this part, they say, in consequence of
being much compressed, puts on the appearance of
nervous striae : whereby, they add, its connection with
the iris becomes established. — During life the retina is
transparent, the choroides shines through it and gives
color to the pupil ; but speedily after death it loses its
transparency and exhibits a dead or opaque whiteness :
immersion in spirits of wine produces this opacity at
once and gives to the membrane a little firmness. It
appears merely to be an expanded mass of nervous
pulp ; but, scraping the surface of it as it floats in
water shows it to be resolvable into a pulpy or medul-
lary part which becomes dispersed in the fluid, and an

174 The Humors.

extremely delicate membrane whose texture has been
found to be almost entirely vascular : the latter forming
the basis or vascular network upon which the former
is spread, and by which it is nourished and supported.
This membrane is intimately united with the edges of the
opening that gives passage to the nerve, and receives
its vessels from the central artery of the retina which
takes it course through the axis of the optic nerve.

The Humors

Are three in number, viz. the aqueous, ckrystallme,
and vitreous ; and they occupy in succession the spaces
in the anterior, middle, and posterior parts of the
globe.

The aqueous humor escapes as soon as the cor-
nea is punctured, and the cornea itself falls afterwards
into wrinkles, showing that the tension of the one is
owing to the presence and pressure of the other. It
fills the interval between the cornea and chrystalline
lens,' insulating the iris by which the whole space is
divided into two cavities, named the anterior and pos"
terior chambers : these chambers consequently commu-
nicate through the pupil ; but they are very unequal in
their dimensions, the posterior being nothing more than
a very narrow chasm between the uvea and the lens,
surrounded by the ciliary processes whose points may
be said to project into it. The aqueous humor is a
bright limpid fluid, and in its properties bears a great
resemblance to the vitreous, in the state in which the
latter drops from its cellular case : they are both com-
pounded of albumen, gelatine, and muriate of soda,
suspended in a watery menstruum. This humor, as
well as the others, has a capsule of its own ; at lea.st,

The ilumon.

175

we infer so from analogy, or rather from the separabi-
lity of a thin transparent lamina from the concavity of
the cornea which has not the fibrous character of the
other corneal laminae, and which some have been able,
they say, to trace upon the iris ; though no one, I
believe, has seen it enter the pupil : this membrane is
supposed to secrete the humor ; and, if we may judge
from the rapidity with which the fluid is reproduced
after it has been let out, its secretion is by no means
either a difficult or expensive process.

The chrystalline lens, though a solid body, is
always considered as one of the humors ; it is named
chrystalline from its resemblance to chrystal, and lens
from its shape. It is lodged between the aqueous and
vitreous humors, the latter presenting in front a hollow
bed for it, surrounded by the ciliary processes and
parted from the iris by the posterior chamber. The
lens is inclosed within a capsule of its own, by whose
attachment to the tunica vitrea it is retained in its
place, assisted by the membranula corona ciliaris.
This capsule, the tunica chrystallina of some, is denser,
firmer, and more resisting than the tunica vitrea;
it cannot be shown to have any adhesion to the lens
itself, there being between them an aqueous moisture,
which some regard merely as a post mortem exudation,
while others consider it as necessary during life to pre-
vent adhesion of the contiguous surfaces, and call it the
aqua vel aquula Morgagni, from its discoverer. The
anterior part of the capsule is thicker, stronger, and
more elastic than the posterior part ; though the latter
is something strengthened by the membranula ciliaris,
and is closely, but not inseparably, united by a fine
cellular web to (and therefore is not, as some have

176 The Humors.

supposed, conlinuous in substance with) the tunica vitrea.
Successful injections show the vascularity of the cap-
sule ; and those who believe in the existence of a liquor
Morgagni, suppose it to be a secretion from these ves-
sels, which themselves are derived from the central
artery of the rentina.

The lens in figure approaches more or less to a sphere ;
it is not uniformly spherical however, but is composed
of the segments of two unequal spheres, the posterior
of which has more convexity than the anterior.
Though perfectly transparent, it has this peculiarity
in its composition — that it is soft externally but gra-
dually increases in firmness and density of substance
from the superficial to the central part, which latter is
denominated its nucleus. It appears to be placed as it
were in a state of insulation within the capsule ; for we
cannot detect any cellular, vascular, or other direct con-
nection between one and the other, and we constantly
find both their surfaces moist with the liquor Morgag-
ni, which renders them so slippery that whenever the
capsule is wounded the lens readily makes its escape.
— The nature and composition of the lens is a subject
still open to- inquiry : as it is in other doubtful and
obscure cases, where anatomical tests forsake us hypo-
thesis is ready to supply their place, and, as in the pre-
sent instance, now and then furnishes us with some
ingenious and plausible conjectures. Dr. Young*
thought that at one time he saw in the lens of a bul-
lock's eye muscular fibres with intersecting tendons,
to which he ascribed the power of augmenting its
sphericity: indeed Mr. Hunter had a notion that

* You KG " On Natural Philosophy."

t

The Humors. 177

it possessed a power of varying its figure, and had
made some allusions to a fibrous structure. These sup-
positions, however, of a fibrous texture, have all sprung
from examinations of the lens in an opaque and al-
tered state : so long as it remains pellucid, though
its substance certainly does come away in spherical
iaminfE, there appear no grounds for ascribing a fibrous
composition to it. Notwithstanding the physiological
ingenuity therefore of these hypotheses, all that we are
absolutely warranted in offering upon the subject of its
composition is rather the result of chemical inquiry
than any demonstrable knowledge we possess of its or-
ganization. In the living animal, it is as transparent as
the clearest chrystal : after death it gradually loses its
pellucidity, and more rapidly when immersed in water, by
which it is converted into an opaque pulpy mass. Even
if it is simply squeezed between the fingers it turns
opaque : a change ordinarily explained by saying, that
we have destroyed its organization and extravasated its
fluids. Acids and alcohol have the same effect that
boiling water has upon it ; they convert it into an
opaque, white, firm body, such as we see it in the
head of a boiled fish. It is found to be chemically
composed of albumen, gelatine, and water ,• and this
seems to be the sum and substance of our pi*esent
knowledge of its conformation. Neither blood-vessels
nor nerves have ever been traced into it ; nor are we
certain that it is organized at all, unless we receive as
proofs the ordinarily assigned tests of organization — the
phenomena of growth and morbid changes.

The vitreous humor fills the posterior con-
cavity of the globe, tlie dark chamber, nearly four-fifths
of its whole interior. It is of the consistence of thin

PART III. N

178

The Humors.

jelly, and from its pellucidity and glassy appearance
has got its name. It is moulded to the form of the
cavity containing it, and lies in contact everywhere
with the retina, though there is no connection between
them unless the ciliary artery can be considered one.
Beyond the boundary line of the retina it is covered
by the corpus ciliare ; and in front is scooped into the
form of a hollow bed for the reception of the lens. — If
this tremulous mass be pricked or otherwise wounded, a
transparent fluid drops from it, very like water, leaving
behind a thick and gelatinous part which at length
becomes condensed into a membranous substance : this
residue, which contained the humor, and is said to be
disposed for that purpose in small cells, varying in fi-
gure and size, is called the tunica vitrea vel hyaloidea.
Opposite to the corpus ciliare this membrane is double:
one part of it lines the hollow containing the lens ;
the other advances under the ciliary processes, for
whose reception it is arranged into an equal number
of radiated longitudinal folds, with depressions between
them, .which proceed to the border of the lens and
adhere to the anterior circumference of its capsule.
The portion of black pigment between the ciliary pro-
cesses and these plicae adheres to both; so that when
the processes are stripped oft' the plicae are seen
marked with a regular series of black striae forming a
radiated circle aronmd the lens, which appearance has
obtained the name of membranula corona ciliaris for
this folded portion of membrane. This being the ar-
rangement of the divisions of the hyaloid membrane, it
follows that there must exist a triangular interval or
canal around the capsule of the lens, which forms the
base of it, with indentations in its front side : this is

21ie Humors.

179

the canal of Petit or canalis Petitianus. This canal has
the breadth of the corpus ciliare, behind which it is
readily inflatible. It has no communication with any
other part. — ^The fluid which escapes from the punc-
tured mass, though of greater specific gravity, is much
the same in appearance as the aqueous humor, from
which, I believe, it only differs in the proportion, not
in the number or nature, of its ingredients : viz. al-
bumen, gelatine, common salt, and water.

The arteria centralis retinca takes its course through
the middle of the vitreous humor to the capsule of the
lens ; but we cannot discover any distinct signs of
vascularity or organization in this delicate tremulous
mass.

N

LECTURE LXIII.

^s^sT /s^>^ ^-^^^ ^■^^ ^ ^ ^ ^

On Vision.

Having made himself acquainted with the anatomy
of the eye — with the composition, texture, organiza-
tion, relative situation and connections of its several
constituent jjarts, the student may regard himself in
the situation of an optician who possesses an exact prac-
tical knowledge of the construction of a telescope or
microscope without being able to give the rationale of
its operation : the latter looks through the instrument
he has made, and pronounces the work to be well exe-
cuted ; the former is struck with the apparent simplicity
of structure of the visual organ, contrasted with its
wonderful powers, (with which he has been practically
acquainted from his birth though he has never perhaps
contemplated their sublimity until now,) but, like the
optician, after he has finished his examination, still
remains unqualified to expound the philosophy of vi-
sion. The reason is obvious. Light is absolutely and
indispensably necessary for vision — no animal could
see in a state of (were there such a one as) total
darkness: the phenomena of vision are all produced
through the medium of light, and consequently all op-

On Vision.

181

tical results must have the same origin ; it follows
therefore, that our knowledge must not remain limited
to the structure of the organ or instrument itself, but
be extended to the nature of light and the laws by
which it is regulated before the mind can be prepared
to comprehend the theory of optics and philosophy of
vision.

Various hypotheses, characterised by their respective
depths of ingenuity, have been framed on the nature
of light. The immortal Newton taught, that light
consists of subtile particles emitted in straight lines
from luminous bodies in every direction with great force
and inconceivable velocity. Of luminous bodies there
are three classes, or, in other words, there are three
sources from which we derive light : the great fountain
of light is the sun, the illuminator of the universe ;
secondly, light is artificially produced by combustion ;
thirdly, there is phosphorescent light, which is either
natural or artificial, and is of many and various kinds.
Lisfht derived from one or other of these sources does
not appear to differ in regard to the properties we are
about to discover in it ; it is therefore unnecessary for
us to seek for any distinction between solar and terres-
trial light. Considering light as material, the minute-
ness of its component particles or corpuscules beggars
all description, and not only sets language at defiance
to convey, but baffles human conception to form, any
idea of its state of divisibihty : to what can the imagi-
nation compare that which is said to be considerably
less than one millioneth part of one millioneth of an
inch ! or, that of which it has been computed that a
candle while burning emits every second of time a
thousand times a thousand million of times as many

182 On Vision.

particles as the grains of sand the whole earth contains,
supposing every grain to measure one-hundredth of an
inch in diameter, and the light emitted to be a compo-
nent part of the burning body !

With such incredible, nay, inconceivable velocity
does light move that its motion has been thought to be
instantaneous ; and so limited is the extent of vision
upon the face of our globe that it would not probably
have enabled us to detect the fallacy of this concep-
tion ; astronomy however has not only furnished us
with proofs that its motion is progressive, but even with
data at what rate it travels. Now, it has been averred,
that Flying Childers (a celebrated racer) could run at
the rate of a mile in a minute ; a shot from a cannon
would have travelled in the time about six miles be-
yond the goal ; the sound of the cannon whould have
reached about six miles further during the minute ;
whereas, light ! darts through a space of 200,000
miles while the pendulum of a clock makes one vibra-
tion !

I have said that light emanates in straight lines from
luminous bodies in all directions : a candle placed in
the middle of the room equally illumines everything
around it, and the light which ray eye or any object in
the room receives, may be regarded as so many straight
lines, consisting of series of particles of light, drawn
from it to the flame of the candle,, which lines are
technically called rai/s ; unless when they shoot in ra-
diance directly from the sun, and then they are named
beams or sunbeams. If a ring therefore be held between
the eye and the flame of the candle, it is evident that
the rays passing through the ring must collectively
form a perfect cone of light, of which the eye is the

On Vision.

183

base the candle the apex or emanating point. Suppos-
ing that the rays meet with no interruption they con-
tinue to diverge to their farthest extent ; their divergent
tendency however is found to diminish in the long run
in inverse ratio to the distance, insomuch that at a
great distance their divergence is so trifling that it is
not cognizable by the laws of optics ; and so the
extreme rays have been called, to distinguish them
from those nearer to the source of light, 'parellel rays.
Again, the light immediately emanating from the can-
dle is intense and effectual ; that proceeding from the
same body at a distance is faint and weak : this
is attributable to the rapid dispersion of the particles,
and to the lengthening of their intervals, which latter,
it is found, bears an exact ratio to the square of the
distance.

When a ray of light impinges any body it is either
reflected, or absorbed, or transmitted. By reflection is
meant, the recoil of a ray from the surface of a body
which it has impinged but cannot permeate : it is simi-
lar in result to the rebounding of a ball or any elastic
body (for reflection is peculiar to elastic bodies) from
the surface of a wall against which it has been thrown :
the ball meeting with resistance recedes or turns back,
not, it is supposed, from a continuation of its former
force but in consequence of its elasticity. Hence, re-
flecting bodies are called opaque, in contradistinction
to others which give passage to Hght, and which are
therefore said to be transparent. It is by reflection of
light that objects are rendered visible to us, and that
they appear to us of this or that color. Metals
possess the property of reflection in the highest degree,
more especially when their surfaces are made smooth

184

On Vmon.

and bright : hence arises the employment of them in
common lanterns. Glass is another equally if not still
more potent reflector : the representations in a mirror
are formed by reflection ; its quicksilvered back refuses
transmission to the rays, which consequently become
reflected, recoil and strike the eye of the observer.
Lastly, respecting reflection, it is a law, that the angle
of reflection is ever equal to the angle of incidence :
this is evinced when I behold an object in a mirror
though neither the object nor my eye is placed opposite
to it ; for, it will be found, that a straight line drawn
from my eye to the glass will form the same angle with
its surface that one drawn from the object does. This
is the principle on which the camera obscura is con-
structed .

Light, in impinging some bodies, in permeating
others, becomes absorbed or extinct. Bodies of every
composition and color possess this property in a degree ;
but some vastly more than others. Opaque absorb
much more light than transparent bodies ; and black
more than any other color : white, least of all.

Those bodies, I repeat, which light freely permeates
are distinguished as transparent ; they are also named
media, since they transmit the fluid from one place to
another. In entering a transparent medium whose
density is dissimilar from the one it has just left, a ray
turns from the rectiUnear line it was pursuing before
and takes another inclination, tending either towards
or digressing from the perpendicular according as the
new medium be more or less dense than the former one
was : the perpendicular being that ray which falls per-
pendicularly upon the surface of the medium, and one
which, for that reason, proceeds in the same undeviating

Oh Vision.

185

straight line in which it entered. This deviation of the
ray from its former course is called refraction, which
literally signifies broken: and the ray actually is bent
or broken at its very point of entrance into the new me-
dium. The familiar illusion of immersino- a stick in a
pail full of water, by which the stick appears to be bent
or broken at the surface of the water, and the immersed
part to be more elevated than it really is, is a good
illustration of this ; but, raise the stick upright and it
will appear perfectly straight to the bottom of the pail.
It is not the stick, we know, that is bent; it is the
rays of light reflected from the part under water which
become broken in shooting into air, and which conse-
quently produce in our vision the optical illusion of a
broken stick : were it possible to place the eye of the
spectator under water the portion of stick standing out
of the pail would appear bent, but, then, the bend
would be in the contrary direction. Facts and experi-
ments akin to this one have led to the induction of two
of the general laws of refraction. 1. A ray of light, in
passing from a rarer to a denser medium, is drawn to-
wards the perpendicular. 2. But, in passing from a
denser to a rarer medium, it is turned from the perpen-
dicular. To which may be added, in a general sense,
the denser the medium the greater the refraction.
There is yet another law which deeply interests us to-
wards the understanding of the theory of vision. And
that is — a ray impinging a curved surface of another
medium will be refracted after the same manner as if
it fell upon a plane placed in contact with the curve at
the point of incidence : in other words, the effect of a
dense transparent body of a convex figure will be to
collect and unite the rays all into one common point.

186

Chi Vision.

which we c.ill the J'ucus ox focal point ; while that of a
dense concave body will be to separate and disperse
them. What is meant by a focus is practically shown
by the use of a burning-glass, as it is commonly called :
this, we know, requires to be held at a certain distance
from the object destined to receive the effect, in order
that the rays may all be refracted as they pass through
and collected afterwards into one lucid spot ; and this
spot is denominated ih^ focus from the circumstance of
its being found to impart heat. Glasses having convex
or concave surfaces are called by opticians lenses ; and
there is a variety of them in use to answer different
purposes ; without, however, inquiring what these seve-
ral glasses and their respective uses are, it is absolutely
imperative upon us to prosecute to a certain extent the
analysis of the common lens or we cannot fully under-
stand the optical operation of the chrystalline of the
eye. The axis of a lens is determined by a right line
drawn through it perpendicularly to its two surfaces,
and which, when both these surfaces are convex, neces-
sarily passes through both their centres : from which it
is manifest that no lens, unless it be perfectly spherical,
can have but one axis. Now, if a ray of light strike in
the line of its aiis, it will pass through the lens without
experiencing any refraction ; but, if an oblique ray im-
pinge, it will be refracted, and, providing the lens be a
convex or a plano-convex, refracted inward so as to
intersect in some point the line of its axis, should both
be extended, or, what comes to the same thing, so as
to form a focal point with a ray coming in a similnr
manner from the other side : the oblique rays being
refracted in lines drawn perpendicularly to tangents
carried through the points of refraction. All the rays

On Vision.

187

however falling upon its surface will not have one and
the same focus ; those which impinge farthest from the
axis will meet soonest after refraction, and this effect is
increased, cateris paribus, in direct ratio to the thickness
and convexity of the lens. This cursory view of the
nature of light and the laws of reflection and refraction
will serve to prepare the mind for the consideration of the

Uses of the different parts of the eye.
The contents of the globe we have found to consist of a
series of diaphanous parts of various forms and densi-
ties which are freely permeable to light, and whose com-
bined operation may be stated summarily to be, to col-
lect the rays, reflect them in their passage, and bring
them to a focal point upon the retina : the share of re-
frangibility each part singly possesses can only be rough-
ly estimated until their respective configurations, relative
densities and proportions, shall have been accurately as-
certained ; data that can alone enable us to make this
calculation with mathematical correctness.

Rays of light radiating from any object of vision form
cones whose apices are the points of radiation and whose
bases impinge the cornea : the rays that chance to fall
upon the sclerotica or any other opaque part are reflect-
ed, as are also those that strike the cdrnea in a very
oblique direction, beyond a certain angle, and this re-
flection it is that diffuses the lustre around the transpa-
rent part of the eye which is so characteristic a feature
of animation, and one that the painter's art can but
very imperfectly imitate.

The cornea serves then to collect the rays and to
refract them towards the ocular axis : it is, metaphori-
cally speaking, the glass or window of the eye, the
part of the case formed to admit the light ; for it sup-

188

0?i Vision.

plies the place of the sclerotica in front, in containing
the aqueous humor and resisting external injury. Its
size and figure, and the position of the eye in the head,
give the horse a commanding lateral view. The horse
enjoys a much wider range of lateral vision than man,
and he can direct it backwards which the latter is una-
ble to do ; this extensive and varied view serves to
guide him with more certainty of success in his rambles
over ample plains of pasturage in quest of food, and
must prove a great advantage to him in the season of
danger ; indeed the faculty of retrospection seems to
have been given him with the same design that the re-
troaction of the ear was, to enable him the better to elude
pursuit : it is said that the hare in the chase will often
turn one ear backward to gathei' the sounds of her pur-
suers while she keeps the other presented forward to
avoid perilous encounters in her course ; if this be true,
may she not possess the power of thus advantageously
disposing of her eye-sight ? That hares can and do di-
rect their view backwards is proved by the fact of some
being known in the course to run blindly against trees
or posts chancing to stand in their way, and dash
themselves to death. But there is an additional reason
why a horse should possess retrospection ; for, since
his principal weapons of defence are his heels, with
what degree of certainty could he have directed their
stroke without this faculty ?

The AQUEOUS humor maintains the convexity of
the cornea, and gives steadmess and support to the iris
in motion, keeping it at proper distances from the cor-
nea and lens, and preserving the figure of the pupil :
it also refracts the rays of light. In the human subject,
the cornea is said to have too much convexity in some

3

On Vision .

189

instances from nial-conforn\ation, tlu; eft'ect of which is
to convero;e the rays to a focus too early — before they
have arrived at the retina, and consequently to render
such persons near-sighted : I am not clear in my mind
about the existence of this preternatural convexity in
horses, though there are goggle-eyed staring counte-
nances occasionally seen which might reasonably raise
such suspicions, especially if such horses proved to be
very shy. A man has it in his power to correct this im-
perfection in a great measure by the use of concave
glasses ; but, in horses, should it ever show itself, it
must be regarded, I fear, as irremediable. The eyes
of old persons commonly suffer some diminution of their
general tension, the natural consequence of the perma-
nent activity of the absorbent system through the de-
cline of life, and this detracts more or less from the re-
fractive force of the organ ; the consequence is that
these people grow long-sighted, i. e. the rays do not
converge early enough, and therefore they require con-
vex lenses as additional refractive agents.

The iris plays a very important part in adapting
the eye to vision. Being extended like a curtain through
the middle of the aqueous humor, it will limit the quan-
tity of light admitted, compelling those rays that do gain
admission all to pass through the very middle, the
densest and most convex part, of the lens, or permit-
ting others to accompany them through the superficial
and softer parts of that body, according as it is at the
time in a state of dilatation or contraction. In a weak
light the pupil becomes dilated in consequence of the
contraction of the iris, in a strong hght the reverse of
this happens ; and, if the eye be exposed on a sudden
to a glare of light after having been kept closed or ob-

190

On Vision.

scured for a time, so dazzling and irresistibly exciting is
the effect that vision is altogether intercepted for the
moment by the complete closure of the pupil : however,
the organ speedily accommodates itself to the intensity
of light, the iris again contracts, though very limitedly,
and distinct vision is restored. It has also been ob-
served, that the iris vs^as dilated in looking at a near
object, but contracted in viewing a distant one ; and
this observation has been brought forward to show,
that the iris has the power of adjusting the eye to dis-
tances : the fact itself however has by no means been
accurately examined, and the inference has turned out
to be a very vague and insupportable one; for, in
looking at the sun the pupil is greatly contracted, and
it will be much more contracted in viewing a small than
a large object, though both be placed at the same dis-
tance from the eye. Indeed, the facts altogether seem
to bring us back to our former induction, and to be
only reconcileable on the principle, that it is by the
quantity of light that the iris regulates its motion, which
is paramount to distance, though the latter will influ-
ence them when the magnitude of the object and the
light by which it is viewed remain unaltered. A remote
object requires more light to render it. visible than a
near one, and the pupil is contracted in viewing the
latter, not that it may adjust the eye to the distance,
but that it may exclude the light which is now super-
fluous and which would consequently operate against
distinct vision. The effect of light on the iris is not so
striking in horses as in a man's eye : were a surgeon
called on to examine the iris of the former he would
pronouuce it to be sluggish in its motions. Any attempt
to frame a reason for this would necessarily involve us

On Vision.

191

in the unsettled question — What is the efficient cause of
these motions ? It is certainly not any inherent suscep-
tibility to light in the iris itself, as has been imagined ;
for, if a strong light be thrown upon its surface while
the pupil is closed, no action whatever is produced ; ad-
mit the light however to the interior of the eye and the
pupil will instantly vary its dimensions according to the
intensity or quantity of the light. * This very naturally
engendered an opinion, that the iris moved in sympa-
thetic connection with the impressions light made upon
the retina, whose exquisite sensibility, it was said, re-
quired an internal guard to moderate the light admitted ;
but, if this were the true explanation amaurosis ought to
be accompanied by a motionless pupil, and the activity
of the one ought to be regulated by the susceptibility
of the other ; which, though generally, is not unexcep-
tionably the case, for instances now and then present
themselves, in human medicine particularly, in which
the iris is found to retain its moving faculty and activity
even though the eye itself is amaurotic. This notable
exception however, though it tends to increase the per-
plexity of the subject, does not put aside the result of
all our ordinary observations, that the iris is consider-
ably influenced by the condition of the retina and by
the effect that light has upon the nerve. Independently
of this physiological connection, a mutual sympathy
constantly exists between the iris of one eye and that
of the other : though one pupil be permanently closed
and impenetrable to light yet will the iris of that eye,
providing it preserve its soundness, undergo the same
movements as that of the healthy eye ; and this is a
fact that we should bear in mind at the time that we
are examining eyes. Mr. Lawrence has observed,

192

On Vision.

that during sleep, in that quiescent state of the organ
which accompanies the repose of the external senses
and the sensorium, and the general relaxation and rest
of the voluntary muscles, the pupil of the human eye
is greatly contracted ; and, to add to this list of irre-
concileable and inexplicable phenomena, the same dis-
tinguished surgeon informs us, that he has seen two
cases in which all tKe parts supplied by the third pair
of nerves — the three recti, the obliquus superior, and
the levator palpebrse superioris, were paralysed, so that
the lid could not be raised and the globe was drawn to
one side, and yet, in both cases, the pupil was largely
dilated ; not from the optic nerve being insensible to
light as might be supposed, for, when one of the pa-
tients looked through a small opening made in a card,
producing what may be called an artificial pupil, vision
became perfect.

By what power or agency the iris moves, has not, no
more than the nature of the excitation required to pro-
duce motion, been yet discovered. It was reasonable
to ascribe its motions to muscularity, and it was natural
to regard the fibres said to exist in its texture as the
muscles themselves ; but, anatomy has not furnished
us with indubitable evidence on this point, and there
are some strong objections to be raised against any
arguments that may be built upon analogical deduc-
tions. Light, which according to this doctrine is
the natural stimulus of these muscular fibres, appears
to produce the very contrary effect to what stimuli do
on other muscles ; the stronger the light is the more
dilated or relaxed is the iris ; and in this same condi-
tion we find it during sleep while the voluntary mus-
cles are all relaxed : moreover, mechanical and chemi-

On Visioti.

193

cal stimuli of all kinds, and even galvanism, fail to ex-
cite any action whatever in it after death.

The cokpora nigra, I am of Professor Cole-
man's opinion, serve as shades to the pupil ; with this
advantage, that they not only intercept but extuiguish
light. When the i)upil contracts into the form of an ob-
long slit, leaving an aperture in the middle only, these
pendulous bodies are seen to project in front of the
aperture ; on the contrary, when the pupil is dilated
they are elevated, and so much so when the dilatation
becomes extreme that they are scarcely visible. Their
operation appears to me to be this —When the animal
is grazing, in which dependent position of the head
solar rays would be particularly annoying to him, the
corpora nigra superiora are projected over the pupil to
intercept and extinguish them, whereby the pupil can
be kept in a state of comparative dilatation to admit
light from the pasture immediately around him ; with
the exception of that place which he has just passed
over, the rays reflected from which will strike so ob-
liquely that they also will be arrested by the corpora
nigra inferiora.

The chrystallin f-: lens is the part that possesses
the refractive property in the highest degree. And the
rays in their passage through it undergo a decussation
which is in perfect accordance with the principles of
optics : hold the lens up and view the candle through
it and the candle will appear inverted, the same as it
would through a common lens. The chrystalline, in
fact, is an optical instrument for converging the rays
and bringing them to a focus upon the retina ; when
therefore it is removed for cataract it becomes necessary
to supply the deficiency by a highly convex glass with-

PART III. o

194

On Vision.

out which the patient can enjoy no useful vision. This,
after all, is but an imperfect substitute for it however ;
for it must be remembered that the lens diminishes in
density from the central to the superficial parts, soften-
ing nearly to the consistence of the aqueous humor on
one side, to that of the vitreous on the other : a pecu-
liarity in its composition which, it is believed, serves
to correct the tendency to aberration * consequent upon
the sphericity of the cornea. Another advantage aris-
ing from this structure is, that the lens will transmit
the rays without reflecting any of them from its anterior
surface, or causing any to be reflected from its pos-
terior side, which, according to the laws of optics, it
must have done had the superficial parts possessed
greater refractive force than the aqueous and vitreous
humors contiguous to them : an effect that would have
weakened the retinal picture. Thirdly, opticians reck-
on that this peculiar structure renders the eye achro-
matic or colorless; i.e. that it refracts the pencils of
rays without decomposing them into their primitive
rays, which are colored : an effect that requires consi-
derable optical skill to avoid in the construction of tele-
scopes and microscopes by duly proportioning the radii
of the curvatures of the different lenses, and one that

* Aberration, in optics, is this — Rays of light impinging the sur-
face of a lens will not all meet iu one and the same focus, if the
lens be convex, nor will they have the same virtual focus should it
be concave ; those rays which strike the surface of the former
most distantly from its axis will converge the most, and the differ-
ence will be greater in proportion to the thickness of the glass and
the extent of its spherical segments. This compels the optician to
make his lenses as thin as possible ; even thereby however he can-
not obtain one common point of convergence, nor is it iu his
power unless art can imitate the structure of the chrystalline.

On Vmon. 195

in the eye must have been productive of indistinctness
or confusion in vision. In fine, the chrystalline lens
transmits the rays without reflection, and refracts them,
whatever be their degree of obliquity, in such ratio to
their different points of transmission that each pencil
forms a focus with uniform precision, be the distance of
the object of vision what it may, upon the concavity of
the retina.

The vitreous humor appears to be for the pur-
pose of giving sphericity to the dark chamber of the
eye, in order that the retina may be spread smoothly
and uniformly over its coxicavity, and thereby display
ample surface for the representation of objects of vision :
at the same time, being perfectly pellucid, it offers no
interruption to the rays of light in their passage to the
retina.

The dark chamber I have described to be the cavity
filled by vitreous humor. It may be compared to a
camera obscura, the pupil representing the aperture
through which light is admitted into that optical ma-
chine ; for it appears no less necessary to produce vivid
representations that reflected or superfluous light should
be extinguished in the eye than that the room of the ma-
chine should be in a state of total darkness. The ni-
grum pigmentum of the choroides and ciliary processes,
and the uvea, may be said to constitute the darkening
apparatus ; for, these parts being perfectly black absorb
the rays that strike against them. This, in man, is the
case with eveiy part of the choroid surface ; for, though
the pigment is rather a brownish than a jet black, it
reflects probably little or no light : but, in the horse
and other quadrupeds the part of the pigment fight
and brilliant, which we call the tapetum, instead of ab-

o 2

196 On Vision.

sorbing the luminous rays striking through the retina,
reflect them back upon the membrane ; an effect that,
though it probably weakens the picture in a strong
light and renders the eye less tolerant of such rays,
produces a more distinct retinal impression in a feeble
light ; thus giving these animals the advantage by
night, the time when they are prowling about in search
of prey or food. In the horse the tapetum is a varie-
gated pea-green, a color probably selected from its
harmonizing with that of his pasture, and so establish-
ing a congeniality between the incident and reflected
rays, a circumstance that would seem to favor this par-
ticular kind of vision, and enable him to graze at night
as well as by day ; and this description of vision is
still further promoted by the greater extension of the
tapetum over the upper than the under part of the
chamber. Prudently, therefore, does the benighted
traveller act who commits himself to the guidance of
his horse when his own sight can no longer penetrate
the darkness he is journeying through ; his faithful
steed will pick out the road home when his rider can
hardly see the animal's head before him : and this is an
advantage the horse mainly derives from the reflection
of the tapetum, though the comparatively large dimen-
sions of the cornea, and correspondently dilated pupil,
must also be taken into the account, in consideration
of the quantum of light admitted. It is this reflection
of light from the bottom of the dark chamber that
gives the strikingly beautiful illumined appearance to
the eyes of cats in the dark, and the sea-greenness
to the pupils in horses. Those animals in whom the
pigiAent is altogether wanting, see in the dark with
still more distinctness : ferrets, who seek their prey in

On Vision. 197

dark holes under ground, have eyes of this description.
The rays then that fall so obliquely that they pass
through to the nigrum pigmentum become absorbed ;
while those that impinge within the sphere of vi-
sion and strike the tapetum, become reflected, the
more direct through the pupil diffusing through it
a beautiful lustre, the more oblique against the uvea
and ciliary body where they also become extin-
guished

The retina is the part upon which the object of
vision is depicted, and the optic nerve conveys the im-
pression made thereby to the sensorium. A question
has arisen, whether the retina be susceptible of impres-
sion in every part. Excepting the place where the
optic nerve enters we have no evidence that it is not ;
but, since a perfect image can only be formed upon that
part which is within the axis of vision, and since the
mind is intent upon that image alone, other objects,
imperfectly formed from being without the visual axis,
are not recognised by the sensorium : the farther ob-
jects are painted from the axis the greater this imper-
fection, until rays enter too obliquely to produce any
effect at all. Though the limits therefore to the admis-
sion of light are only bounded by the pupillary opening,
distinct and perfect vision is confined to that part of
the retina upon which the oblique rays meet in focal
points with those that strike the middle of the cornea
at right angles and proceed in straight lines through
the centres of the pupil and lens to the bottom of the
eye, which points are called the visual or optic axes.
Most objects of vision being situated below the line of
the head, these axes in general fall above the porus
opticus ; did they strike upon that place, it is said.

198

On Vision.

they would take no effect ; in proof of which is brought
the following experiment — Hold two objects at arms'
length in the same lateral line, near to each other,
directly in front of one eye, and then shut the opposite
eye ; this done, move one of them in a direct line out-
ward while the view is kept steadily fixed upon the
other : it will be found that the one in motion will
disappear for an instant ; and this is explained by
saying, that just as it disappeared the visual axis struck
upon the porus opticus. Perfectly distinct vision re-
quires that the object, as well as the organ itself,
should be fixed ; when anything is seen in motion, the
image, though perfectly made, is of too fleeting a
nature to make that impression upon the nerve which
the sensorium requires for accurate and minute exami-
nation. Calculations have been made about the time
of duration of the impression, particularly in regard to
luminous objects of which it is the most effective and
lasting : the familiar optical illusion of the circle of
light produced by whirling round a lighted stick proves
that the impression really does remain after the object
has been removed.

Of the refractive operation of the lens the effect
is, on the principles of optics, that those rays which
impinge the upper part of the cornea strike the lower
part of the retina, and vice versa, in consequence of
their intersecting one another m their passage through-
the lens ; it necessarily follows therefore, that the
image painted upon the retina must be an inverted
one. And to prove to demonstration that it is so ; take
a fresh eye, carefully dissect off the posterior parts of
the sclerotic and choroid tunics so as to bare the retina
in an entire state, over which, if it be found necessary

On Vision.

199

to support the humors, may be laid a piece of thin
oiled paper ; this done, present the cornea to the flame
of a candle, and a miniature picture of the candle will
be seen upon the retina, burning downward. Now,
what is the reason of our seeing objects in their true
position, since the retinal picture is indisputably an
inverted one ? This has long been a problem of consi-
derable curiosity and interest in vision. Some philo-
sophers have contended that we really did see objects
turned upside down, but that we detected the illusion
by touch , and by habitual experience at length corrected
in the mind the visional deception : this might seem to
deserve some attention in the human subject, but it
is obvious that animals must behold things reversed all
their lifetimes had they no other means save the sense
of touch to rectify their view ; but, in truth, there is
no reason to believe that infants are so deceived ; and
we know that persons born blind see objects in their
right position the moment their sight is restored. Be-
sides, if this were true, even those who are experienced
ought to see things reversed for the first time ; whereas
we know that they are not thus misled. The most
plausible rationale of this phenomenon, is, that it is not
the picture painted upon the retina but the object itself
that the sensorium takes cognizance of ; that certain
sensations are excited in the brain by the impressions
made by light without any reference to what part of the
retina may have received them : were this not the case
we should be constantly subject to mis-conception in
the form and position of things ; for it is quite irrecon-
cileable with every rule of perspective and painting to
suppose that objects could be represented, such as we
see them, in the eye.

200

On Vision.

There is another phenomenon in vision that has exer-
cised the inventive genius of the philosophical world ;
which is, there being two eyes, and consequently two
retinal pictures, why is not vision double ? With refer-
ence to what has just been said in explanation of the
inverted image, it may be answered, that, as it is not
the picture but the object itself that is mentally seen,
though two impressions ai'e made upon the nerves but
one sensation is produced in the sensorium ; and this
rationale has been pursued further, by ascribing the
cause of only one sensation being excited to the im-
pressions being made upon correspondent points of
the retinae ; in support of which is adduced the
child's trick of pushing the eyeball to one side with
the finger, which we know causes double vision, aris-
ing, it is said, from altering the visual axis of the
impressed eye. If this be sound theory, it may na-
turally be asked, why do not persons who squint see
double then, since the visual axes in them certainly
cannot accord ? To this query it is replied, that, as
squinting in most cases arises from defective vision in
one eye, the other alone is used for sight; and from
habit the impressions received by this eye are so strong
compared with those taken by the imperfect one that
the latter pass away unnoticed.

How much two eyes extend the view, and what
advantages are thereby obtained I need not expatiate
on ; but I would call attention to a disputed point con-
nected with this part of our subject. It is said that in
intent vision we only exert one eye, and that the object
consequently is not diminished in lucidity and distinct-
ness by closing the other. It appears to mc however
that this only holds true of persons who have acquired

On Vision.

201

the habit of employing one eye on such occasions more
than, or to the total exclusion of, the other ; and that
I can myself perceive objects plainer with both eyes
open than with only one. It is argued against this,
that vision then ought to be doubly strong, since the
object is equally seen by both eyes. But, we do not
find that double impressions excite doubly strong sen-
sations in instances of common feeling, and why should
we look for such a result in this particular sense ? The
loss of one eye does not enfeeble sight because the
other acquires greater energy, though it much contracts
the field of vision. It is said to render the conception
erring ; and the case of mis-judgment of distances is
the one commonly brought forward to show this. All
I can say on this point, is, that the best hunter I ever
possessed, a horse gifted with extraordiliary powers for
leaping, was a one-eyed horse ; and this animal carried
mc through a hunting season, principally with Lord
Derby's deer-hounds, without, to ray recollection,
making a single blunder in leaping : he had a cataract
when I bought him, and therefore I cannot say how
long he had lost his eye-sight.

That peculiar beauty in the structure of the eye by
which it adjusts itself to the distance of the object
of vision, forms a subject yet open to inquiiy. The two
prevailing theories of the day are rather to be consi-
dered as prepositional than as superseding the necessity
of future investigation. One hypothesis is, that the
focal distance is regulated by alteration in the figure of
the lens, which seems to involve the supposition of its
muscularity. The partisans of the other theory con-
tend that this cannot be wholly true, or else, how could ^
the eye preserve this faculty after the operation for

202

On Vision.

cataract ? I'hey say, the organ is adj usted by the com-
bined actions of the four straight muscles, which, by
compression of the globe, lengthen the axis of vision,
push the lens and ciliary body forward and thereby
increase the curvature of the cornea. To say the least
of this latter theory, it is a very ingenious one, and,
though with the other destitute of proof, carries with
it a verisimilitude that the former cannot boast of.

■i

LECTURE LXIV.

A^SA ^S^^ «S^S^ ✓.A^ ^^*NA AvAsT ^S/N*' ./S^S^

0/1 /Ac Diseases of' the Eye.

TThE diseases to which the eye of the domesticated
horse is obnoxious, when compared in number with the
many set down by opthalmic writers to the organ in
man, are certainly very few ; but there* is one among
them that has proved in all ages of veterinary medicine
so pestilential, and that even at the present day so
obstinately pursues its end in spite of all remedial
measures, that this of itself, in my humble opinion, is
a sufficient reason for us to become well acquainted
with the anatomy and physiology of the eye, and pay
more than ordinary attention to it in a state of disease.
But there is another reason, not less cogent, one that
is ingeniously urged by Professor Coleman in his
lectures, why we ought to cultivate this knowledge,
and be vigilant in the season of disease, which is this —
If a man have disease or defect of his eyes and a sur-
geon is only able in part to relieve him so that he
regains but an imperfect vision and that vision through
the aid of glasses, he is grateful and goes away satis-
fied ; but, if a horse be brought to us whose eyesight
is lost and we cannot restore it to a state of, or ap-

1

204 On the Diseases of the Eye.

proaching to, perfection, without any assistance from
the optician, our art has proved of little service to the
horse, and probably has been productive of conse-
quences mischievous to his owner; for, so long as the
animal continued blind, under the judicious governance
and guidance of his rider, he proved himself to be still
very useful ; but now that he can perceive glimmers of
light and imperfectly view the objects in his road, he
mistakes one thing for another, shys at what he was
familiar with formerly, and turns out a very troublesome
servant. There is yet another motive for possessing
this acquisition. The community finding how indis-
pensable it is that the horse's eyesight should be per-
fect, are in the habit of consulting us on the soundness
or healthiness of his eyes. But how, I would ask,
is that veterinarian prepared to answer this question in
all its bearings and relations who professes merely to
know practically a sound eye from an unsound one ?
Such a man may silence the groom and very possibly
gull his master ; but the very first time he encounters
anybody whose estimation is worth seeking, he will be
set down as an ignorant pretender. And since this
inquiry is a very interesting one I shall make here an
observation or two concerning it.

The horse whose eyes become the subject of inspec-
tion is ordinarily placed in such a situation that light
may fall upon the eye but in one direction, and to in-
sure this being in the axis of vision, the face should
not be presented to the rays (which is the common
practice) but the side of the face ought to be turned
with a certain degree of obliquity so as to confront the
eye directly with the light : not however that this is
often required by those who are accustomed to such

Oti the Diseases of the Eye. 205

inspections, nor even expedient in every case, for there
are eyes that can be viewed plainer in the open light.
To an experienced veterinary oculist the aspect of
health is so familiar, and the ordinary imperfections so
striking, that he pronounces the organ at the first
glance into its interior to be sound or unsound ; and
here the inquiry too frequently ends : there is perhaps
some unnatural appearance in the eye, no matter what
or how it originated, and a certificate is granted vouch-
ing for its unsoundness. But, should the horse have
been brought for the purpose of having a detailed and
correct opinion given of the nature, cause, duration,
and probable termination of the malady, or to be sub-
jected to prompt and decisive treatment, then does the
mere man of practice wallow in his ignorance, while
the accomplished professional man unravels every link
in the chain of disease, fully and satisfactorily explain-
ing its nature, boldly and effectually administering his
remedies. There is no more ready mode of qualifying
oneself for this important part of one's duty, the discri-
mination between soundness and unsoundness, than
that of accustoming oneself to the appearances of eyes
in perfect health : judgment itself is but comparative,
the better therefore we become acquainted with the
signs of health the more nicety shall we be able to
exercise in the detection of disease. In these inspec-
tions we should not depart satisfied with barely looking
into the organ : we ought to compare one eye with the
other ; mark the prominence of the membrana nicti-
tans ; the transparency and convexity of the cornea ;
the pellucidity of the aqueous humor; the color and
brilliancy of the iris ; the color, figure, and size of the
pupil; the magnitude, blackness, and prominence of

206 On the Diseases of the Eye.

the corpora nigra ; and last but not least of all, repeat-
edly mark the activity with which the pupil alters its
dimensions on suddenly admitting light to the eye.
These are the leading features to be borne in mind in
the inspection of either sound or unsound eyes : what
states and appearances of parts denote health I need
not recapitulate ; and those that characterize disease
will be detailed hereafter.

The eye is liable to inflammation, common or
specific in its nature and consequences, to cataract,
and to amaurosis: but, before I proceed to analyse
these affections I must be permitted to make a few re-
marks on some opthalmic maladies to which the horse
is not subject. This may at first appear a strange and
irrelevant digression ; but, I must defend tlie charge
by informing the student, that there are published ac-
counts abroad of the diseases of the eyes of horses
with authority enough attached to them to mislead the
tyro ; and I hold it to be no mean acquisition to us, as
travellers upon the high road of fact and truth, to be-
come acquainted with the by-roads of fallacy and mis-
representation*.

* It is very natural for a man to sit himself down in his study
and imagine, since he finds llie same description of mucous, serous,
and fibrous textures— of muscular, glandular, and nervous struc-
tures in a horse's that he does in a man's eye, that the one should
be aflFected -w'xih many, if not all, of the disorders to which the
other is known to be obnoxious ; but, in point of fact, the human
eye, according "to Dr. Rowley, who has written a work entitled
'■^ A Description o/" 118 of the Principal Diseases of the Eye," is
liable to disorders exceeding in number the horse's maladies altoo-e-
ther; and there not only exists this wide difference in regard to
number, but there is one opthalmic disease to which the horse's eye
is exceedingly prone which is not to be found at all in the lon^

207

Common or Simple Opthalmia.
Though no distinctions are made either in the na-

catalogue of those affecting the human eye, nor equalled by any
one of them for its irremediably destructive tendency. Here is
then a memorable example to show the folly and danger of erecting
a nosological fabric upon an analogical foundation. We appear to
trace the signs or effects of inflammatory action, variously modi-
fied, in almost every individual texture of the eyeball and its appen-
dages in man, and no one could rationally deny the possibility of
such occurrences among horses ; but, if I am to be guided by such
deviations from health as are herein seen in the course of practice, I
must exclude the nominal affections I am about to notice, for which
some writers have with their pens inoculated the horse.

Affections of the tarsus, in which, either from defective or morbid
secretion in the Meibomian glands, the eyelids are found adhering
together after having been kept closed all night, the horse is exempt
from : I do not even remember to have seen a single case of op-
thalmia in which this was a concomitant symptom. Of what is
called fistula lachrymalis, a very troublesome disorder consisting in
obstruction of the nasal duct whereby the sac becomes distended
and the tears run over the face, 1 never saw an instance of myself ;
though Professor Coi-EMAN mentions a solitary case in his lectures.
The disease known by the name of purulent or jnij-iform opthalmia
is unknown in veterinary practice : either in the form it assumes
in children, when it produces such excessive tumefaction of the lids
that the surgeon opens them with the utmost difficulty, or is com-
pelled to relinquish his efforts altogether, to gain a sight of the
conjunctiva, which is found to present a wrinkled and villous sur-
face, and to pour forth a thick yellow matter in surprising profu-
sion ; or in the contagious form in' which it attacks the adult, called
the purulent, contagious, or Egyptian opthalmia, when the eyelids
are also so tumefied that it is exceedingly irksome and painful to
force them open, and a thick yellow matter is discharged over the
face which will communicate the same disease if applied to a
healthy eye, and which, if bold and effectual measures be not taken
early, will speedily occasion ulceration and rupture of the cornea,
and thus end in the total destruction of the organ.

208 Common or Simple Opthalmia.

ture or tendency of common inflammation seated in the
same textures, yet there are two remarkable points in
which this affection circumstantially differs in the eyes
of men and those of horses. First, as it attacks the
human eye it is considered as a spontaneous or idiopa-
thic affection, and has been so named — opthaimiiis dio-
pathica; but the affection in horses has, I believe I
may say unexceplionably, some apparent or assignable
cause. The animal appears to be exempt from this
affection on the same principle that he is less subject
to idiopathic disorders in general, not by nature per-
haps any more than man, but from a less irregular mode
of living, a mode that art can do little to subvert :
were it possible to induce the horse to indulge in the
excesses of luxurious fare, and to lead altogether such
an indolent and intemperate mode of life as passes with
too many of us for refinement, the same disordered
states of the chylo-poietic viscera would probably alloy
his pleasures, the same morbid excitement and its per-
nicious consequences pervade his system as is never
absent from theirs who spend their days so contrarily
to the designs of Nature, so ruinously to themselves.
Secondly, robust persons whose habits of life dispose to
plethora are especially liable to an inflammation attack-
ing at one time both the external and internal tunics
of the eye — an opthalmia characterised by a general
scarlet redness of the organ ; by chemosis ; (a deposition
of lymph underneath the conjunctiva ;) by violent
pains in the eye, shooting through the head, and often
by a sense of the globe, from actual enlargement, being
too large for the orbit ; by a general tumefaction of parts ;
and by the inflammatoiy fever consequent upon such
violent local symptoms. In horses, on the other hand,
the seat of common inflammation is the conjunctiva :

Cummun or Simple i)pl/ia//nia. 209

unless in an event of direct inffniy to the parts I do not
remember to have seen a sinole case of common mter-
nal opthalmia.

The seat then of common opthahnia is the conjunc-
tiva, and its causes are external ; its nature, on the
principles of inflammation, is simple, and its symptoms
are few and characteristic. The principal symptom is
redness, by the extent and intensity of which is mainly
to be reckoned the violence of the attack ; for it may
vaiy in degree from simple vascular congestion, a con-
dition denoted by a vivid carnation hue of the palpebral
conjunctiva and the appearance of some red vessels
upon the sclerotic, to the state of acute inflammation,
evinced by the bright scarlet tint of the lining of the
lids, by a thick vascular network covering the opaque
cornea, from which numerous red vessels shoot into
and obscure the transparent part : these states of the
membrane are only to be correctly estimated by evert-
ing and closely exarainmg the lids. Chemosis is rarely
or never seen. There are in general no signs of any
considerable pain : the animal feeds as usual, seems
undepressed in spirits, and appears to be unaflected
constitutionally ; a circumstance that harmonizes well
with the yielding texture of the membrane, as well as
with the little pain felt by ourselves when similarly af-
fected. There is commonly a flow of tears over the
face, attributable to participation in the increased ac-
tion by the lachrymal gland. The eyeball itself being-
free from inflammation, aversion to light is not one of
the primary symptoms, though it may supervene as a
casual one should the ocular vessels sympathize with
those of the lids ; notwithstanding that, however, the
lids will continue contracted and the haw protruded so,

PAHT 111. P

210 Common or Simple Opthalrnia.

long as any cause of irrit)si.tion remains ; a circumstance
that is apt to induce us erroneously to think that the
eye is also affected. Vision is impaired only in the
most violent of these affections, when the transparency
of the cornea is diminished or destroyed by vascular
plethora or the effusion of adhesive matter. The up-
per lid being- ordinarily the seat of injuiy may be more
or less tumified, and such a case may end in abscess
of the lid ; but these parts seldom or never swell spon-
taneously.

In regard to the causes of common opthalrnia, I have
already averred that they are local and mostly apparent,
not constitutional: Professor Coleman and our best
modern veterinary writers all concur in this etiology ;
and I may add, that the disease would never probably
have appeared in print in any other form had the sub-
ject not fallen into hands that have shown themselves
unqualified by experience to pen any very correct or
useful information about the matter. The ordinary ex-
citing cause is mechanical irritation : a blow from a
whip, a bite from another horse, the insinuation of a
hayseed or other irritant underneath the lid, are the
common excitants ; though it rarely happens that fo-
reign matters lodge in the eye, the consequent flow of
tears and the reiterated action of the membrana nicti-
tans being commonly effectual in their removal.
■ The treatment of these cases is in general very
simple. Many of them get well spontaneously after the
irritant has been removed : others have an inflam-
mation excited which requires immediate and active
antiphlogistic measures, such as will suggest them-
selves when we come to detail the treatment of specific
opthalrnia. Should there be present any signs of the

^Specific Opthalinia. 211

retention of the foreign body, uhe most likely situation
to find it, is the concavity of the upper lid ; by elevat-
ing which from the globe or everting it by means of a
probe, Vie shall probably discover a hayseed or particle
of dirt sticking in the conjunctiva.

I may remark here, that it every now and then hap-
pens that a horse gets his eyelid, commonly the upper
one, torn from a bite or from hinging it in the point of
a nail or hook that may chance to be fixed near him in
the stable. I have had two or three such cases, in
which the border of the upper lid holding the cilia was
so rent in the longitudinal direction that it hung merely
by a strip of skin over the front of the eye. These ac-
cidents aflbrd the veterinarian an opportunity of dis-
playing a skill and neatness in the use of the needle,
which may turn out no little to his credit. The torn lid
requires to be nicely adjusted and sewn up with a small
needle and a single thread ; and the sutures should be
cut and removed twenty-four hours afterwards. The
part may be kept wet with cold water ; unless the horse
be very shy about the head, and then this had better
be dispensed with. Should tumefaction of the lid and
redness, &c. of the eye ensue, the case must be treated
as one of simple opthalmia.

Specific Opthaimia.

The moon-blindness of the farrier's nosology, so
named by them from a belief that its relapses were in-
fluenced by the changes of the moon and from its al-
most certain termination in blindness, is the specific
opthalmia of our veterinarians ; but what the latter
mean by specific, I have not been able to make out,
unless it be used as an epithet to denote that this is a

p 2

212 Specific Opthaimia.

disease whose nature or theory is not understood : at
least such appears to be its interpretation in the instance
before us and in glanders and farcy which are also called
specific diseases. Professor Colem a n, who at an early
period of his professional career made this disease the
peculiar object of his investigations, has put to flight the
incorrect accounts in which its medical history was in-
volved together with the absurd and mischievous prac-
tice grounded thereon, and he has set the subject in a
light reconcil cable with that of modern pathology ; but,
after all, though we may have got rid of palpable ab-
surdities, have we advanced in our knowledge of its na-
ture or devised any efi'ectual mode of treating it ? I
fear not ; however, let the sequel of this account be
the answer.

This disease, it would appear from the ordinary ac-
count of the case, generally makes its attack at night.
The groom discovers in the morning that the horse has
got a " bad eye," and he seldom fails to report either
to his master or the veterinary surgeon in attendance,
that the animal must either have received a blow or
some foreign matter in the eye in the course of the
night. And indeed the eye itself betrays appearances
externally that seem to favour this fallacy of the groom's ;
for the upper lid droops, giving the organ a weak or
gloomy aspect, the haw projects, and tears flow over
the under lid and bedew the cheek : but, when we
come to inspect the interior of the organ we find the
cornea so dull that the iris can hardly be seen, and the
eye so impatient of strong light that considerable efl?brts
are made by the lids and haw in opposition to any at-
tempts we may make to distract the lids by force. The
most effectual mode of obtaining a full view, is to turn

Specific Opthairnia. 213

the head from any direct or strong light, and then the
animal will open the eye sufficiently to admit of inspec-
tion. The pupil will be seen more or less narrowed, to
contract with unusual celerity and force when turned to
the light, and to have a hazy aspect through the dull
filmy cornea ; the iris also will have greatly suffered in
brilliancy and perhaps will show some partial or a gene-
ral appearance of discoloration. As the disease proceeds
the cornea continues to lose its lustre and pellucidity
until we can no longer distinctly see through it, which
may be the consequence of its increased vascularity or
of some interstitial eftiision ; even the aqueous humor,
I believe myself, grows turbid, so that from both these
causes we can obtain but a very imperfect view of the
iris : there are cases however in which the iris turns of
a dead amber hue, from a coating of adhesive matter,
before the cornea becomes obscured. The corpora nigra
also after a time lose their jetty blackness, and the
pupil becomes so contracted that we can hardly see
throuijh it at all. These internal marks of disease are
attended generally with conjunctival inflammation : in
some cases the membrane becomes intensely reddened,
red vessels clothe the opaque and crowd around the
margin of the transparent cornea across which numbers
of them shoot in serpentine lines ; in other cases the
conjuntival affection is less violent. It is to the tumid
condition of this membrane that the fullness and ten-
derness of the lids and the apparent enlargement of the
haw are owing, and that the eye itself seems shrunk
and more retracted than under circumstances of health.
In the more advanced stages hypopyon is often present :
and the case may, 1 am told, terminate in suppuration of
the whole globe and consequent disruption ; but 1 have

214 Specific Opthalmia.

not met with the occurrence in my own observation -
Light opaque spots are occasionally seen upon the cor-
pora nigra, showing that they are also participators in
the morbid alterations. But the common ending of all
this inflammatory disorganising action is cataract : as
the inflammation abates the iris gradually contracts
again, disclosing a hazy greyish pupil which would ap-
pear to result from the effects of disease in the substance
of the lens, and which we know practically to prelude
to a cataract ; for, I repeat, ultimately, almost all these
cases proceed to the formation of cataract. The pupil
at the same time may or may not become contracted
and rendered a fixture from adhesions : very commonly,
where the other eye is sound the pupil of the cataractous
one moves in unison with its fellow. The iris is more or
less permanently altered in aspect and color. The cornea
may have recovered its pellucidity or be clouded with a
white and permanent inter-laminal deposition. These
are in general the only visible alterations of structure ;
but it seldom happens, I believe, that the retina and vi-
treous humor, not to mention other less important parts,
are free from organic impairment. Occasionally we
meet with eyes which are nothing but bulbous masses
of disorganization and alteration of structure. The
cataract perhaps has been thrust through the pupil into
the aqueous humor ; or it has driven the iris before it,
and that has grown to the transparent cornea ; perhaps
the vitreous humor too has made its escape into the front
chambers, whereby all the parts are so cemented toge-
ther that scarcely a vestige of healthy aspect remains.
In some cases I have found the lens in the dark cham-
ber, floating about in the vitreous humor; and in
others, both the lens and its capsule on examination

2

Specific Optkalmia. 215

have proved to be partly converted into bone. But to
particularize the infinite varieties of states and appear-
ances to vi^hich the organ is reduced by this destructive
malady, would far exceed my present limits and do so
to very little purpose.

Some writers regard the conjunctival affection as the
principal, others as the primary disease. To the former
it is scarcely needful to reply. The latter, I am inclined
to believe, rest their opinion upon the conspicuousness
of the more determinable sign of inflammation, viz. red-
ness, in that part, beyond other signs perceptible only
on close and accurate inspection in the interior of the
eye. But, the irritable iris, the contracted pupil, and
the general dullness and muddiness of the transparent
parts, together with their subsequent change of color
and aspect, are symptoms that denote morbid action
within as strongly as redness and swelling do without
the organ : it argues therefore, to say the least of this
opinion, a narrow view of the case to reason upon such
slender premises though they be undeniable facts. If
the disease were primarily conjunctival why should it
so invariably extend to the globe ? Common inflam-
mation we know hardly ever does so. And why should
not the disease destroy also the texture of the conjunc-
tiva if that be its primaiy or principal seat ? So far
from doing this however is it, that the membrane we
know seldom or never sustains any injury. It might
with infinitely more reason, in my opinion, be desig-
nated iritis than considered either principally or prima-
rily as an opthalmia conjunctiva.

It must not be inferred from the description here
given of its ordinary or regular course that the disease
proceeds rapidly and without intermission to the total

216 Specific Optlialinia.

destruction of the organ ; on the contrary, it is compa-
ratively tardy in its progress, and effects this final de-
struction by relapsing after considerable intervals of ap-
parently restored healthy action : the paroxysm com-
monly continues for a month or six v^reeks, and then
subsides altogether ; leaving the eye, should it have
been the first and not a very violent attack, to appear-
ance unimpaired, only that it may evince rather more
susceptibility of light than the sound eye, shedding per-
haps a tear or two and twinkling a little when suddenly
exposed, and having its haw rather more irritable and
prominent than the opposite one. The disease is seldom
seen in both eyes at the same time : a paroxysm will run
through its course in one eye, and in a month or two
afterwards a fresh attack will show itself in the other ;
or, should that not prove to be the case, almost to a cer-
tainty a relapse will invade the eye first attacked ; pass-
ing through certain inflammatory stages, and afterwards
leaving the organ more or less impaired in structure and
of course in function. Its ordinary mode of proceeding
is to attack alternately first one eye and then the other
until both have experienced such morbid alteration of
structure, the most conspicuous and common mark of
which is cataract, that the animal is left permanently
and incurably Wind. This general and complete disor-
ganization is ordinarily followed by a cessation of the pa-
roxysms; not invariably however, for there are cases in
which they continue to return even after vision is totally
lost. Raiely both eyes, I repeat, show this disease at the
same time ; but I have seen many cases in which I have
not been able to detect it in the opposite eye, though
it has pretty regularly relapsed in and ultimately de-
stroyed the other. In short, in regard to the violence

Specific Oplhaliniu. 217

and duration of the paroxysms, the length of the remis-
sions, and the relapses and alternations, the disease is
not reducible to any known laws, either physiological
or pathological.

More or less lingering febrile action invades the sys-
tem during the continuance of the paroxysm ; but it is
too mild seemingly to be productive of any indisposition,
ior the animal retains his appetite and spirits, though
at the same time his pulse denotes febrile disorder, and
his secretions and excretions perhaps manifest the same
indication : should he be kept at work however during
the opthalmia an inordinate disposition to perspire may
probably be remarked, together with consequent dull-
ness or unusually early symptoms of lassitude. If it be
a local affection therefore it is one that makes some im-
pression upon the system at large. But, Professor
Coleman views it as a constitutional disorder ; and I
think I shall be able to show that this opinion, so far
from being erroneous, is one that we ought to keep
steadfastly in view inasmuch as it may be regarded
as a beacon to direct us to the discovery of its origin :
it has certainly taught us practically a pretty certain
mode of warding off its attack. Some of our modern
practitioners are in the habit of drawing an analogy be-
tween this disease and gout, and so they call it " the
gouty opthalmia. " These disorders assuredly both very
commonly make their attack during the night, and
both disappear after an uncertain duration, and return
at irregular intervals ; but, here I apprehend the com-
parison (if such it can be called) must end : so far as we
are acquainted with their etiology, they arise from very
different causes, and are seated certainly in very differ-
ent parts ; while one is in a great measure controllable

218 Specific Opthalmia.

by art, but the other pursues its course with but little
variation or intermission in spite of all our boasted
efforts.

In the course of his researches into the origin or pro-
duction of this opthalmia, Professor Coleman from
extensive observation was led to believe that the same
contaminated atmosphere which is known to engender
glanders and farcy, sows the seeds of disease in the pre-
sent instance. Horses running wild and breathing the
untainted open air are never thus affected, " at least,
I never saw such a case," says the Professor ; and of
those that are domesticated, fami and coach and post
horses are the common subjects of opthalmia; and so
were formerly the cavalry horses, when they stood in
ill-paved, ill-drained, unventilated stables. Some
writers suppose that it never attacks mules or asses ;
but this is a mistake : the mules belonging to the army
in the Peninsula were quite as often the subjects of dis-
eased eyes and glanders and farcy and mange as the
horses were ; indeed, it struck me forcibly, at the time
I was serving with the British Artillery there, that the
mules especially suffered from malignant diseases con-
tracted in ill-constructed filthy stables. Shall we say,
by way of a summary rationale, that the effluvia arising
from the breath, perspiration, urine, dung, &c. gene-
rate an animal poison, and that this, being in a gaseous
form, is diffused through the atmosphere of the stable,
and with it carried into the system through the medium
of the air-passages, skin, or alimentary canal, most
likely by the first but possibly by all of them, wherein
it breeds disease in the circulating fluids, which breaks
out, under a local form, in the lungs, skin, nose, eyes,
&c. ? or, shall we say, that these parts are affected lo-

'Specific Optkuhnia. 219

cally in the first instance and subsequently contaminate
the system ? Let us postpone the consideration of an
answer until we come to include glanders in the same
family of poisonous influences. Professor Coleman
adduces as proofs that it is not a local affection. — Is^.
The constitutional derangement, which he says may
often be traced to the digestive organs and skin, and is
in some respects unlike simple irritative disorder. 2dli/.
The character of the inflammation, which is neither so
acute nor so rapidly progressive as simple opthalmia
often is, and yet the one readily yields to proper treat-
ment, while the- other obstinately continues its course.
3dli/. The eye may be locally exposed to volatile ammo-
nia or any animal effluvium we can obtain by artificial
means, and no such effect will be produced.

The most rational indication in the treatment of a
disease is that founded on the solution of its cause —
cestimatio causoe ssepe solvit morbum, is a maxim
which it would be well for those veterinarians who are
so given to stumbling upon cures to have their pre-
scription-books indorsed with : it might save them
much fruitless labor and anxiety and perhaps no little
credit in the course of their well-meant but ill-judged
investigations. It may be said, that we have skipped
over the proximate cause of this disease. Had I any-
thing satisfactory to offer upon the subjct I should
cheerfully embrace this opportunity; but as I have
not, I must leave it in the hands of those who gave
the opthalmia the epithet specific. It is certainly a
species of inflammation, and is apparently constitu-
tional in its origin though local in its consequences ;
we may therefore betake ourselves to the adoption of
antiphlogistic means, and apply them constitutionally

220 Specific Opthalmia.

as well as locally, though we shall fail to make that
impression which we do in simple phlegmon, and ul-
timately have the mortification to learn, that our ef-
forts, though they may have delayed, have not
prevented the fatal issue, permanent and irremediable
blindness. It is the common practice to draw blood,
and now and then we appear to do so beneficially :
the evacuation should not be sparing, and the jugular
vein of the same side as the affected eye will be
opened with the concurrent advantages of local and
constitutional depletion. The temporal artery is some-
times chosen, but in my opinion without prospects of
equivalent . eflfect, since none of its branches run to
the eyeball. The angular vein is opened with still less
benefit. Blood may be locally drayvn also by leeches
and by scarification : the former, generally speaking,
are too expensive for veterinary purposes ; the latter
may prove beneficial in simple opthalmia when there
is considerable vascular turgidity of the conjunctiva,
but cannot be expected to do much good here. But
to show how very ineffectual the abstraction of blood
occasionally proves, I may state here, that Professor
Coleman, after having drawn as much blood as the
system could withstand, has placed ligatures around
the carotid and facial arteries ; nay ! he has even
taken the pains to excise from the front of the eye
one by one the red vessels that were seen shooting
from the opaque into the transparent cornea, and
seared the parts around the line of separation after-
wards, and yet this has only put a temporary check
to the inflammation ; after a short lapse of time the
paroxysm has returned in all its former violence and
obstinately persisted in its destructive course. If

Specific Opllia/mia. 22\

bleeding: do mitigate or shorten the duration of the
paroxysm, and I conceive that it generally does so
myself, it is much more efficacious in the early
than the late stages ; and in order to derive the full
effect we must draw blood until we have sensibly
diminished the foite and frequency of the action of the
heart : this is the only chance we have of bleaching
the eye by venesection. Doubt seems to hang over the
practice of purgation. I have certainly seen purges
relieve the vascular tension, particularly in the early
stage ; but I must add, that I have occasionally
looked in vain for the same apparent relief : Professor
Coleman informs us, that he has attended cases in
which the paroxysm, though abating at the time, was
evidently renewed by purgation ; and he believes that
the debility consequent on this operation is likely to
pre-dispose the animal to a fresh attack. I have often
remarked, especially towards the decline of the in-
flammation, that the eye became considerably clarified
by blisters, applied upon the temples or cheeks ; they
are not very cleanly remedies unless one be washed off
before another be applied, and then there can be no
such objection made to their use : I do not advocate
the farrier's practice of rubbing a liquid blister indis-
criminately over the eyelids and parts adjacent; it
stiffens and disfigures the lids, and runs into the eye,
and often aggravates instead of relieving the disease.
Setons in the vicinity may be productive of some
benefit in the chronic stages. Professor Coleman
has exhibited calomel and the hydrarg. oxy-murias,
and I have pursued his steps, but without the desired
effect : the mouth may be rendered sore in the course
of three or four days, so sore that the horse will cud his

222 Specific Upthalmia,

food, and this effect may be carried to salivation, and
consequent starvation from inability to masticate, and
yet the disease continue unabated and apparently un-
influenced. Various tonic and other medicines have
been administered at random in hopes of drawing a
prize : but they have one and all turned out blanks.
The cupri sulphas was started as a specific when I was
a pupil at the Veterinary College ; but it has proved
to be only "a nine days' wonder." I have made
trial of the liquor arsenicalis, the sulphate and subcar-
bonate of iron, and various preparations of barytes ;
they have all however failed to arrest or even check
its progress. The advocates for the locality of this
affection, those who build their hopes of cure upon
various eye-powders and eye-washes have been equally
foiled in their attempts : I do not mean to deny the
occasional utility of them as co-operative with consti-
tutional measures, but of themslves they are next to
valueless. The vinum opii and the liquor plumb, sub-
acetat. dropped into the eye will often afford tem-
porary relief, even in the primary stage ; but the as-
tringent metalUc solutions, particularly those of zinc
and copper, should be studiously abstained from so
long as any active inflammation continues. Simple,
poppy, and chamomile fomentations are recommended
to us by medico-veterinary writers : they are very
harmless remedies, but the evil is, they are occasionally
very teasing in their application ; for a horse is that re-
fractory sort of animal that, when he has a sore eye,
has no notion of holding his head still to have it
played with. He may probably without much trouble
permit his eyelids to be wetted occasionally with cold
water or the lead wash, and I believe that will answer

Specific Opt ho /mi a. 223

the purpose quite as well. Light and air being stimu-
lants to the organ in health, it most undoubtedly
ought to be shielded from both in disease ; and this is
a part of the treatment commonly too much neglected :
the animal should be placed in a dark but properly
ventilated stable, or winkers or shades ought to be
worn by him : blinds are apt to do more harm than
good by confining a heated atmosphere around the eye.

By the judicious employment of some or all of these
means we commonly do, or are apt to think we do,
hasten the departure of inflammation and ward off or
mitigate some of its consequences ; but an experienced
practitioner is too well aware of the liability and for-
midable certainty of a relapse to repose any faith in the
duration of a truce so obtained ; and therefore his ordi-
nary advice to the owner is to dispose of his horse
during the interval of remission. Knowing, therefore,
as we do, that such horses are continually changing
owners, it is a qualification of the first importance to us
in practice to be able to discriminate between an origin-
ally sound eye and one that has been visited with this
malady : vision may possibly be unimpaired in the
latter, but we are not to suffer our opinion to be lulled
to rest upon such a slippery pillow as this. Any single
one of the following appearances may, unless its origin
can be satisfactorily traced to simple opthalmia, excite
our suspicions ; but a combination will certainly war-
rant an unfavorable prognostic — A sunken or gloomy
aspect of the eye altogether, compared with the other ;
prominence of the membrana nictitans ; vascularity or
pinkness of the conjunctiva ; a watery state of the eye ;
dimness or cloudiness of the cornea, particularly around
its margin ; dullness or discoloration of the iris ; cor-

224 Cataract.

pora nigra yellowish or whitish or spotty ; pupil smaller
than the other, perhaps hazy or milky, or containmg a
minute white speck in its centre, which is an incipient

Cataract.

An opacity partial or complete of the lens or its
capsule or both, is called a catarau : and this is one,
and the most common one, of the effects of internal or
idiopathic opthalmia. A grey or white speck is first
perceivable in the very centre of the pupil which slowly
and gradually enlarges until it quite blocks the aper-
ture : vision grows less and less distinct during its for-
mation ; but, even prior to the speck being visible it is
found that human vision is something disturbed. The
growth of the incipient speck during the time that the
organ is suffering from opthalmia is commonly rapid ;
but, as soon as the inflammatory action has subsided
its progress becomes comparatively slow, and now and
then it appears to remain quite stationary. For, as
soon as cataract has formed the inflammation generally
begins to decline, and the eye seldom receives another
attack : there are however, as I stated before, some
exceptions to this. And it is also, I believe, an ascer-
tained fact, that, not only does the inflammation per-
manently leave the cataractous eye, but, should the
other have remained free from the disease it is in less
danger of being attacked ; under such circumstances
therefore a cataract is hailed as a favorable omen : this
is explicable seemingly on the principle of sympathy
which is known to have great influence in opthalmic
pathology, and the circumstance has been considered
weighty enough to recommend the artificial destruction
of one eye in disease to preserve the other in health.

Cataract. 225

It is found that persons who have imperfectly formed
cataracts see best in weak lights, the pupils being then
dilated and giving admission to more rays through the
circumferent and unobscured parts of the lens : no
doubt, the same thing happens with horses, but when
once their vision becomes confused they grow so shy
and troublesome that they would prove more serviceable
perhaps in a state of total blindness. The presence of
cataract in the eye of the horse is not so manifest as in
that of man ; in the latter the defect is clear and deter-
minable, in the former it is often hazy and has occa-
sionally given rise to dispute of its existence even
among professional men : the rationale of which is,
that the natural French-greyness of the pupil of the
horse makes but a weak contrast with the greyish white
speck when compared with that formed by the dark
pupil of a man. In order to descry an incipient cata-
ract (for one fully formed is seen plain enough) view
the eye in various lights and directions, compare the
pupils, and if one appear smaller than the other look
very narrowly into the centre of the former, and there
will probably be perceived a speck scarcely larger than
the head of a pin : but, should no speck be discernible
and yet the pupil be small and have a hazy aspect,
examine the activity of the iris, the result of which exa-
mination, though it must not singly be considered as
determinate, may serve to increase your suspicions, and,
coupled with other appearances and considerations, lead
to a pretty correct conclusion.

Cataract may either be capsular or lenticular ; or it
may be both, and then is termed mixed ; and a lenti-
cular cataract may be firm, fiuid or milky, or caseous in
consistence : the first is the common variety among

PART III. Q

226 Cataract.

horses. Though there may be other causes for its pro-
duction in the human subject, in whom cataract, it is
said, may be of scrofulous, arthritic, venereal, heredi-
tary, congenital, or local origin, I believe that it will be
found to be invariably in horses one of the consequences
of opthalmia ; for in cases where no signs of increased
action have attended its apparent formation, they may
be generally discovered to have existed at no very re-
mote period preceding it. I do not mean to assert that
it never happens without inflammation : I have heard,
and so far I believe, that it does ; but it certainly is
comparatively a very rare occurrence. Since we are
professedly ignorant of the structure or composition of
the lens, since we cannot even take upon ourselves to
say for certain whether it be an organised body or not,
it is not reasonable to expect that we should be able to
unfold the nature or formation of cataract ; but it cer-
tainly appears, at least in horses, rational to view it as
an effect of inflammation, and having from facts and
circumstances come to this speculative deduction, here
our knowledge of the subject may be said to end*.

* In the human subject, cataract, it is said, has been cured by
internal remedies. Be this worthy of credit or not, there have cer-
tainly been well-authenticated cases of spontaneous cures happen-
ing in various ways : surgeons however at the present day place no
reliance upon these doubtful and casual results ; they have recourse
at once to an operation which has for its object the removal of the
opaque body out of the axis of vision. There are three modes in
practice of effecting this. One, termed couching, consists in de-
pressing the lens into the dark chamber, where it cannot interfere
with vision. This operation is performed with a needle of a par-
ticular make, which the surgeon introduces through tlie sclerotica,
about two lines distant from the margin of the cornea, and one
line below the transverse diameter of the globe; he directs its point

Catamcl. 227

Possessing a smattering of tliese proceedings, per-
sons often come to us and ask, why such operations are

to the summit of the cataract, and then gradually brings it round
in front of the lens, behind the ciliary processes ; which done, it
becomes visible through the pupil ; the point is now raised again,
its flat side is applied to the upper part of the lens, and by a gentle
s.weep' of the needle the cataract is deeply buried in the vitreous
humor. There is auotlier operation with the needle, but it is one
commonly confined to cases of congenital cataract. In this in-
stance, the needle is thrust into the transparent cornea near its
junction with the sclerotica, and carried with its flat side opposed
to the iris parellel with and close to that membrane, taking especial
care not to wound it ; here, the object is to lacerate and destroy
the capsule only, to an extent equal to the circumference of the
pupil, and then simply to sink the needle into the body of the lens;
or, another method is, to penetrate the sclerotica with the needle
about one-eighth of an inch from its union with the -cornea, push
the point almost to the centre of the lens and then turn it forward
through the pupil, and afterwards backvvard again, so as to break
both the lens and its capsule into many pieces and drive them be-
fore the needle into the aqueous humor ; the principle of both these
methods being to expose the substance of the chrystalline to the
aqueous humor, which is believed to be a solvent for it, whereby
in process of time the cataract becomes dissolved and absorbed,
and the other parts ultimately recover their original integrity and
transparency.

But the most finished operation is extraction. A spear-pointed
knife, varied a little in make according to the conceptions of the
operator, is thrust through the cornea just above its transverse dia-
meter and before its union with the sclerotica, and is pushed, with
its side parellel with and close to the iris, through the same portion
of cornea opposite, until about one-third of the blade is protruded
from the eye ; after which it is pressed slowly downward that it may
cut its way out below : this makes a section of rather more than
one-half of the cornea, and on the neatness and cleanness of this
section mainly rests the credit of the operator. This done, a
needle, made of nealed gold (to render it the more pliable) is in-

Q 2

228

Cataract.

not performed on horses. In answer to this inquiry we
cannot go the length to say that such an operation is
impossible, but we may with truth declare it to be
impracticable ; and add to this, that, were it practica-
able, it is one that, the least reflection would convince
these querists, can never prove serviceable to such an
animal as a horse. Professor Coleman informs us,
that, after contending with difficulties that rendered
the performance extremely hazardous and the event
almost to a certainty ruinous, he did succeed in com-
pleting the operation for extraction, and the way in
which he proceeded was this — He was compelled first
to fix a double tenaculum into the opaque cornea to
resist the action of the retractor, which resistance he
calculated to be equal to half the force exertible by a
man's arm : by this means the globe was kept advanced
and tolerably steady, and at the same time the mem-
brana nictitans was retained within the orbit. Should
the eye break loose during the operation, it will be so
forcibly withdrawn that the vitreous humor will be
driven through the section ; and the same thing is likely
to happen if the globe be set at liberty suddenly or
incautiously. But, even granting that the operation
has been managed so as to afford some prospect of suc-
cess, the compression occasioned by the joint-operation
of the retractor and membrana nictitans squeezes out
the aqueous humor just as fast as it is secreted or,

troduced through the pupil, and the capsule of the lens is punctured
and torn by means of it : in consequence of this, the lens immedi-
ately escapes and falls against the pupil, and is afterwards forced
out, through the aperture, by a little gentle pressure upon the
globe.

Cataract.

229

should union eventually take place, the iris is almost
for a certainty implicated in the adhesions : and thus
it happens that all our hopes are defeated and all our
argument silenced by such a string of unfavorable and
disastrous events. The Professor therefore has wisely
and humanely relinquished such attempts.

These however are only the difficulties (perhaps not
all of them) met with in performing the operation : let
us now inquire into the obstacles to its practicability at
all. Every man who pretends to a knowledge of optics
must be perfectly aware that after the loss of the lens
the eye requires that art should in some way or another
supply the deficiency, furnish the organ with another
refractor, or how can the rays be concentrated upon the
retina ? Glass is the material used for this purpose,
and it is variously fashioned into spectacles and other
forms convenient for our use ; but I should entertain
no hopes myself of the services of a spectacled horse,
much less should I be a volunteer to ride him ! But,
even suppose for a moment that we could contrive a
pair of spectacles for him, I should like to know how we
are to ascertain what particular lens was adapted to
his sight ? and which glass suited him for near vision,
and which for distant vision ? Independently however
of all this, there is yet another objection to the opera-
tion, one that the practitioner should constantly bear
in mind. Cataract in the eyes of horses being, as
I stated before, almost invariably a sequel of inflam-
matory action, and various other parts being at the
time likewise the seat of disease, it is rarely unaccom-
panied with morbid alterations in other textures : in
fact, it too often happens that there is a total disorgani-
zation of the whole contents of the globe ; unless,

2

230 Opacities.

therefore, we can perform miracles as weli as operations,
and restore all these altered parts to their pristine con-
dition, we had better never think of handling a cata-
ract-knife.

Opacities.

We meet in practice with two kinds of opacities
or films upon the cornea ; and it is of importance
that we should be able to make a distinction between
them, because one is very often removeable, the other
never is.

The permanent opacity is the result of that interstitial
alteration of texture which is one of the sequelae of
the specific opthalmia. It has a yellow or brown tinge
when it first makes its appearance ; but afterwards it
changes to a diflfused muddiness over the whole cornea,
thereby completely destroying both its lustre and pel-
lucidity. We must take care however not to confound
this with the turbid condition of the cornea resulting
from vascular distention and concomitant effusion : this
is one of the symptoms of the opthalmia itself — is only
present with the inflammatory action ; the other is a
sequel of it, remaining the same in the interval of re-
mission, and consists in fact in an organic change of
the corneal texture.

The other species of opacity has been distinguished
by Mr. Tr a vers by the term, nebula ; and the cornea
has, in fact, a truly clouded appearance. This is a
conjunctival affection : its superficiality is evident on a
lateral glance of the eye ; and it is moreover distin-
guishable from the other by its remarkably white as-
pect, and still more certainly (when we can obtain the
information) by its origin. The common forerunner of

Opacities, -231

the nebula is a blow or bite ; though it may result from
a violent attack of conjunctival inflammation: in one
case it consists of adhesive matter deposited to fill up
the breach ; in the other it resolves itself into a thick-
ening partial or entire of the conjunctive membrane.
It is not uncommon to see the whole cornea obscured
in this way in the course of a few hours in consequence
of external injuiy. So long as the adventitious matter
remains unaltered or unorganized, so long I apprehend
there remains a probability of its being removed ; but,
when once it has become organized and assimilated
with the corneal substance, I should conceive that it
must be viewed as a permanent blemish : the elapse of
time therefore becomes an important inquiry and con-
sideration in our prognosis.

Should appearances denote inflammatory action, that
ought to be first subdued by proper antiphlogistic means ;
for it very often happens that with its subsidence dis-
appears the opacity. Should that turn out not to be
the case, we may next make use of some escharotic or
stimulating application in order to excite increased vas-
cular action afresh, and thereby arouse that of the
absorbents. The agent employed for diis purpose
should fall short of an escharotic ; but evtn caustics
may be used provided they are reduced down to tliis
point. There is an endless variety of colly ria and eye-
powders recommended for the«e cases. Farriers are
very fond of blowing finely powdered glass into the
eye, which operates simply as a mechanical irritant.
Calomel, similarly used, has a chemical effect also. I
prefer myself an eye-water to an eye-powder : it is ap-
plied, I think, both with more facility and effect. One.

232 Amaurosis.

or the other of the subjoined collyria* will commonly
answer our end : it should be injected with a small
syringe introduced into the outer canthus. Laxative
and diuretic medicine exhibited at intervals will often
prove serviceable.

Amatirosis.

More commonly called gutta serena, the glass-eye of
farriers, denotes that state of the nervous structures
immediately concerned in vision in which they are
partly or entirely insensible to light. The characteris-
tic symptoms of this disorder are, a preter-naturally
dilated and motionless pupil, which, so far from be-
traying any visible defect, has an unusually lucid or
glassy aspect. Though this is the case commonly in
the human subject, yet, in man, there are many nota-
ble excej)tions ; such as the pupil retaining its proper
dimensions and being capable of motion, or even be-
coming actually more contracted than in health :
and there are cases on record in which the activity
of the pupil has become increased. I know of no such
varieties myself among horses : in them amaurosis is
simply a state of nervous insensibility, referable in every
case that has hitherto come to my knowledge to injury
or disease of the brain. The effect can also be at any

*R Hydrarg. Oxy-Mur. gr. j.
Aquae Distillat. ^. M.
or this,
R Argenti Nitrat. gr. iij.
Aquae Distillat. 5j. M.
Fiat coUyrium simel in die injiciendum in canthum externum
oculi afFecti.

Worm in the Eye. 233

time artificially produced by the application of bella-
donna to the eye. Professor Coleman relates the
case of a horse of his own who received a blow upon
the side of the head from falling backward. After the
fall, hemiplegia invaded the opposite side of the body,
and the corresponding eye became amaurotic. Here,
then, the brain, not the eye, was affected. Bleeding,
purging, and stimulants to the insensible eye, recovered
this horse. The case probably would not have termi-
nated so favorably , had both eyes become paralytic.
There are cases of amaurosis, I am told, to be met
with in which there is no discoverable cerebral affec-
tion ; I do not doubt it, but, for my own part, when
there was no other cause apparent I should always
direct my curative means principally to the brain ; and
they should be of a depletory description. But, as this
is a disease of rare occurrence, and one about which
our knowledge is yet very limited, I shall not waste
time in speculation and hypothesis. In conclusion,
it falls to my lot to broach an interesting subject
which seems either entirely unknown to our veteri-
narians, or, at least, to this day, has remained unno-
ticed by them : I mean

Worm in the Eye.

My own attention has been so recently called to the
subject that I have not had time to investigate it, or
even give it much consideration ; all I profess to do
here is, to state some particulars relating thereunto,
the perusal of which probably may gratify those who
are curious and desirous of any information contribu-
tive to our stock of professional knowledge. In a letter,
dated June 24th, 1825, from my cousin, who is station-

234 Worm in the Eye,

ed with his regiment at Meerat, in the northern part ol
India, I received the following communication.

In low humid situations in India, where fogs are pre-
valent or where there is stagnant water, especially after
an unusually wet season, worm in the eye is a very com-
mon occurrence ; it is also seen occasionally in other
parts during the cold months, from the beginning of
October to the latter end of February, and particularly
during the continuance of an easterly wind. And what
seems very remarkable, is, that these horses are fre-
quently affected at the same time with what the Indians
call knmmiree, which means weakness in the loins. I have
had to treat two cases since I joined the regiment (1824)
both of which occurred within the cold season. The
first was shewn to me the very day after I arrived by
the farrier-major, who reported the horse to have re-
ceived some injury, and the eye to have been bad for
the preceding fortnight. At this time the lids were
shut, the conjunctiva was highly inflamed, the cornea
was obscured from common nebulous effusion, and its
vessels were filled with red blood. On close inspection
I could discern a small white worm floating about in the
aqueous humor, at one time rising to the superior, at
another sinking to the bottom of the chamber. The
following morning I determined on giving this little im-
prisoned intruder its liberty. To this end I punctured
the cornea close to its sclerotic margin ; which done,
the worm escaped with the humor, and was received
upon a napkin. It resembles a piece of fine white
thread, and belongs to the genus Jilaria ; it measures
about one inch and a quarter in length and grows finely
pointed at either extremity. Viewed through a micros-
cope it has the appearance of catgut, and five luminous

Worm in the Eye. 235

marks are distinguishable upon one end of its body
which we suppose to be the head ; farther backward
there is an irregular luminous spot, and from this two
brilliant lines run parellel to the other extremity. After
the operation I employed simple antiphlogistics, and
the horse was sent to his duty six weeks afterwards
with an opaque patch upon the cornea which resisted
all our ordinary remedies. — The second case unfortu-
nately I did not see, owing to indisposition, until the
third day after its reported attack, at which time the
eye had the same general aspect as the first ; though
the serjeant-major informed me that it had appeared
dull for some days before, but that the corneal opacity
had formed in the course of one night. I treated this
case as I did the first. In the first fortnight the upper
half of the cornea became clear again, but the remaining
nebula did not disappear for two months after that ; how-
ever, I effected its entire removal in the end, and I
think I should have been equally successful in the for-
mer case had its origin been of more recent date. If
the worm is suffered to remain, the case terminates in
blindness."

** I have been favored lately with some observations
on the presence of these worms in horses by W. Twin-
ing, Esq. (Surgeon to the Commander in Chief) who
has written on the subject in the Medical Society's
Transactions at Calcutta, from which I will now give
you an extract. — He says Sir E. Home mentions (in
his ' Lectures on Comparative Anatomy,') that the arte-
ries of the ciliary processes in the horse are comparatively
very large ; and that Sir E. is led to believe that the
two species of worms, the strongi/ius and Jilaria, found
alive in the aqueous humor of that animal in India, ob-

236 Worm in the Eye.

tain access through these arteries ; and this opinion is
the more probable since similar worms are known to be
occasionally present in the blood. Mr. T. also observes,
that wonns of the same kind have been found in the
stomach and intestines of horses by Drs. Gibb and
Hartman, Superintendants of the Company's Studs ;
also, by the latter gentleman, in the cellular membrane,
about the loins in particular, in great numbers, and to
their presence there Mr. T. ascribes the kummiree : so
that what has hitherto appeared to be a strange and un-
accountable sympathy between the eyes and the loins,
is probably nothing more than the same affection preva-
lent in the system generally. Mr. T. adds, that seve-
ral circumstances concur to render it probable that the
ova of the filaria equi are received into the stomach with
the food, and that these ova, taken up by the absor-
bents, flow with the blood into various parts of the
body favorable to the development of the worm, which
having been accomplished, its further progress may be
impeded by its augmented size. Sir A. Cooper's ob-
servations on worms found within the cceliac artery of the
ass may be considered corroboratory of all this ; though
it must be confessed the subject yet lacks elucidation.
Dr. Gibb, who has now had the management of one of
the Company's Studs sixteen years, has had on an
average twenty of these cases annually. I have got the
two worms I extracted preserved in spirits, and look
forward to the pleasure of depositing the preparation
before many more years have elapsed in my uncle's
museum.

"Charles Percivall,

"V. S. lUh Light Dragoons."

4

LFXTURE LXV.

Dissection of the Brain.

In my lecture " on the brain and nervous system* " I
defined the brain to be, " that soft white mass which
fills the cavity of the skull." I therein observed, that
the brain in horses was but small when compared to the
bulk of the body ; and that it was divided into three por-
tions the cerebrum, cerebellum^ and medulla oblongata.
I also stated, that it had three coverings or membranes ;
the dura mater, pia mater, and tunica arachnoides.
I then proceeded to speak of the texture and organiza-
tion of the brain and nerves, and concluded with some
general observations on their physiology. It now re-
mains therefore to inquire into the particular anatomical
conformation of the brain, and to make ourselves ac-
quainted with the appearances and relative position of
its several constituent parts, not only that we may be
able to assign particular places of origin to the nerves,
but that we may have clearer notions of the seat and
nature of cerebral diseasesf-

* Lecture x. Part I. which had better now be read over again,
f In order to expose the brain for dissection, after having de-
nuded the anterior and lateral parts of the cranium, first, the

238 Disection of the Brain.

In raising the bony cap we meet with considerable
resistance from the connections between the bone and
dura mater, which, I stated formerly, are of a cellular,
fibrous, and vascular nature : when these have been
torn through, the surface of the membrane shows here
and there bloody spots, which are the ruptured mouths
of the blood-vessels. In describing the texture and
disposition of the dura mater in the lecture referred to,
I made mention of certain expansions or processes, and
canals or sinuses belonging to it : I shall now proceed
to point them out.

The processes are formed by duplications of the
membrane, and are two in number : the falx and the
tentorium. The falx or longitudinal process, so named
from its being resembled to the blade of a scythe, and
indeed the comparison is a striking one, is that expan-
sion of the membrane which descends for a short dis-
tance betwen the lobes of the cerebrum. It takes its
rise from the crista galli, including that process between
its laminae, from which it curves forward and upward,
adhering in its way, first to the frontal, then to the
entire length of the sagittal suture, growing broader
as it proceeds; at length it terminates upon a thin
transverse plate of bone, a process of the os occipitis
anterior, where its laminte split, diverge, and disappear
in continuity with the tentorium. Whatever may be
the use of the falx it seems to be a part whose presence
can be dispensed with ; for I have a cranium now be-

frontal bones should be sawn through transversely, in a direct line
with the summits of the orbital arches; the saw should then be
directed longitudinally, on either side, from the extremity of the
transverse sectio-n, through the temporal muscle, so as to carry the
mcision above the condyloid process of the occiput.

Disseciiou of (he Brain. 239

fore me in which it may be said to be deficient ; at
least, all such appearance consists in a small triangular
piece of membrane which does not project more than
an inch from the tentorium : and this cranium belonoed
to a young horse who was perfectly free from any phre-
netic disorder. The falx is commonly said however to
stay one lobe of the cerebrum from falling or pressing
upon the other when the head is inclined to one side.

The tentorium or transverse process is extended, like
an arch, from the cerebral plate of the os occipitis along
the sides of the cranium to its base, whence, greatly
diminished in breadth, it may be traced onward to the
body of the os sphenoides, where it vanishes in the
common covering of the dura mater. It is composed
of two laminae : one is continuous with the falx ; the
other joins that portion of the membrane which covers
the cerebellum. The tentorium is equally divided by
the falx into two lateral portions. There is some varia-
tion to be seen in different subjects in the figure and
extent of this process, but I have not remarked that it
is ever deficient. It forms a transverse intersection
within the cavity of the cranium, or partial septum be-
tweeen the cerebrum and cerebellum, and appears to
be of service in fencing these important parts in their
proper places, and keeping them, during the various
motions and positions of the head, from pressing upon
each other.

The sinuses most worthy of notice are — Thesuperior
or longituditial sinus, which runs within the duplicature of
the falx, along its superior border. It begins in a nar-
row channel, gradually widens and assumes a triangular
figure as it proceeds backward, and terminates with
the falx at the cerebral process, where the lateral

240

Dissection of the Brain.

sinuses and it all conjoin their canals. Internally, this
sinus presents to view an uneven surface upon which
the veins are seen terminating by large open orifices
that discharge their blood in the same direction which
the stream takes within the sinus itself ; here and there
also are some slender cords crossing the canal from side
to side, which serve to strengthen its parietes and pre-
vent over-distention.

The two lateral sinuses are formed within the duplica-
ture of that part of the tentorium which is attached to
the temporal and occipital bones ; one extending to the
right side, the other to the left side. They begin at
the cerebral process, where the longitudinal sinus ends,
and they terminate at thfe foramina lacera basis cranii
in the jugular veins. Their canals are also triangular,
and are intersected with fibrous filaments. They re-
ceive veins both from the cerebrum and cerebellum.
' The cavernous sinuses, so named from the cavernous
appearance of their interior which includes a structure
having some resemblance to the corpus cavernosum
penis, are formed out of the dura mater upon the body
of the OS sphenoides. These cavities are remarkable
from receiving some important nervous trunks in their
passage from the brain, and for lodging the teraoinations
of the internal carotid arteries. They commonly com-
municate with the

Sub-occipital sinuses. These are also of membranous
formation, and are found upon the cuneiform process
of the OS occipitis, running longitudinally to the fora-
men magnum. They receive veins from the cerebellum '
and posterior parts of the cerebrum.

The dura mater removed, we expose the membrana
arachnoides. I have but little to add to the description

Cerehruni.

241

already given of it. It is with difficulty demonstrable
from its close and uniform application to the pia mater ;
we may now and then however succeed in raising it by
inflation, and the most favorable places for the experi-
ment are, the base of the medulla oblongata, and the
fissures made by the lobes of the cerebellum. From
its extreme tenuity and total apparent want of blood-
vessels, it is so transparent that the parts underneath
appear to be without any such covering : at least, this
is its aspect in health ; but, in the human subject, in
whom these parts are more developed, it is said in a
state of inflammation to betray some appearance of
vascularity. Between this membrane and the dura
mater is exhaled a vaporous secretion.

In regard to the pia mater, I may remark, that the
processes detached by it into the substance of the brain
are only in contact with the cortical parts ; and that
the numerous blood-vessels which are seen ramifying
upon it, are for the purpose of transmitting others of
smaller size into the interior of the cerebral substance,
which, though they here appear to pervade only the cor-
tical, are ultimately destined for the supply of the
medullary matter. This membrane not only clothes
the convoluted exterior of the cerebral mass, passing
from one hemisphere to the other, over the surface of
their uniting medium, the corpus callosum, but it also
gains admission into the ventricles and lines them,
and envelopes and confines in their proper places the
plexus choroides.

Cerebrum.

The largest portion of the cerebral mass, and that
which presents itself to our view on raising the skull-

PAHT HI. R

242

Cerehrum.

cap, is the cerebrum. It is lodged in that capacious
elliptical chamber which is formed in front by the parie-
tal bones, behind by the ethmoid, sphenoid, and poste-
rior occipital bones, laterally by the temporal bones,
inferiorly by the roofs of the frontal sinuses, and by the
ethmoidal plates, and superiorly by the tentorium.
The visible surface of it may be said to represent a con-
vex semi-oval, of which the broader end is turned up-
ward. It is equally divided by a longitudinal fissure
along its middle, into which the falx cerebri descends ;
and its divisions, which are perfectly symmetrical, both
internally and externally, are denominated hemispheres.

In parting the hemispheres, so as to admit light be-
tween them, by which a few small inter-passing vessels
and some weak cellular connections are lacerated, we
perceive a white, longitudinal body, covered by pia
mater, uniting the hemispheres at the bottom of this
fissure : this is the corpus callosiim. Each hemisphere,
separately regarded, has an outward waved or convo-
luted surface, which is adapted to the undulated con-
cavity of the skull-cap ; an inward perpendicular plane,
which is opposed to the opposite hemisphere ; and a
base, divided into lobes, the description of which I shall
postpone until the interior parts have been examined.

In the dissection of the brain I shall pursue the cus-
tomary method of the schools of anatomy, and in des-
cribing its several parts preserve the names used in
human phrenology so long as T find them applicable to
the correspondent appearances. The first step consists
in making a clean horizontal section of the brain, pa-
rellel to its present convexity, by laying the knife flat
upon the surface of the corpus callosum and making a
sweeping cut, with its edge first inclined a little up-

Cerebrum.

243

ward then a little downward, through one hemisphere
at a time. There being no distinguishable parts in the
abscised portions, they may be cast away ; but the sur-
face which their removal has exposed being one that
presents the greatest superficial extent of medullary
substance that can be shewn atone view, the appear-
ance altogether has been described as the centrum
ovale *. The form and disposition of the corpus callosum
are now demonstrable. It is placed in the centre of
this medullary convexity, with which it is continuous in
substance ; it is narrower below than above ; it unites
the medulla of the two hemispheres in the middle ; in-
feriorly, it passes between the hemispheres, turns back-
ward and terminates at the base of the brain, in the crura
cerebri ; superiorly, it joins the fornix, and spreads
upon the hippocampi ; and anteriorly, it may be said to
form the roof of the lateral ventricles. Running along
its surface are two prominent lines of medullary mattef,
between which is a longitudinal linear depression named
the raphe.

By making a longitudinal incision through the cor-
pus callosum, on either side of the raphe, we penetrate
a cavity in the innermost part of the brain, which,
with its fellow within the opposite hemisphere, we dis-
tinguish as the lateral ventricles. Having freely opened
it, we find a watery fluid within, which serves to keep
its parietal surfaces constantly wet, and to prevent ad-
hesion of them. The figure of the ventricle, both from

* The cortical matter however cannot be all pared away — it will
intrude in places and interrupt the uniformity of the surface: in-
deed, the horse's brain will less admit of being carved into such
an aspect in consequence of the proportionably greater quantity of
cortical substance in its composition.

I? 2

244 Cerebrum.

its construction and from the inequalities of its con-
tents, is extremely irregular. It extends as far forward
as the front incurvation of the corpus callosam, from
whence a winding canal is continued forward and down-
ward to the base of the anterior lobe of the cerebrum,
where it ends in a small circular conduit that leads into
the ethmoidal ventricle : this canal, from its being re-
presented to wind in its course like a horn, has got the
name of the inferior cornu. From the superior part of
the cavity, another flexuous passage, smaller than the
former one, taking a direction outward, then down-
ward, and lastly forward, leads to the base of the brain,
through the substance of the middle lobe, and there
has a blind termination ; from which circumstance, and
from its cylindroid figure, some call it the digital cavity,
others the superior cornu. The ventricles are lined (and
the parts within them covered) by an extension of pia
mater, which finds its way into them along with the
vessels forming the choroid plexus. By this membrane,
whose vascularity appears to be lower than that of the
pia mater elsewhere, the watery fluid, it is supposed,
is secreted : unlike serous cavities in general however,
the ventricles appear to hold water during life ; for, if
an animal is put to death suddenly, and these cavities
are opened with all possible expedition, water, and not
vapor, is uniformly found in them.

We now come to what are considered as the contents
of the lateral ventricles. They are — the corpora striata,
the hippocampi, the plexus choroides, the fornix, and
the thalami nervorum opticorum. But, a view of all
these parts cannot be obtained until we have reflected
the corpus callosum ; prior to which being done, that
body should be cautiously raised in order to show the

Cerebrum. 245

Septum lucidum, the translucent medullary partition
between the ventricles, which extends perpendicularly
along the corpus callosum in front, and is attached to
the fornix behind. It is broad inferiorly, grows gra-
dually narrow superiorly, where it ends in a point, at
the angular junction of the corpus callosum with the
fornix. It consists of two thin laminse of medullary
matter, included between and supported by the mem-
branous linings of the ventricles, in the middle of which
is a fissure oi; small cavity, by some described as the
Jifth ventricle, but generally known as the fossa Sylvii.
Sometimes this fissure is very demonstrable and glis-
tens interiorly with moisture ; at other times it is hardly
perceptible.

When the corpus callosum is turned back, four large
and remarkable eminences present themselves, two upon
each side of the septum lucidum. The two inferior,
and most bulky, are the corpora striata. They rise out
of the lower and back parts of the ventricles, project
into the middle of those cavities, where they become
broad and approach the septum, growing narrow and
receding from each other above, below extending along
the anterior cornua. Externally, they have a thin la-
mina of medullary matter, but this is somewhat ob-
scured by the cortical substance of which their interior
is exclusively composed.

The two superior eminences, smaller and whiter than
the last, whose anterior extremities lie between the pos-
terior of the corpora striata, are the hippocampi. These
bodies, remarkable for their prominence and whiteness,
occupy the superior spaces of the ventricles, where
they He in contact with the septum ; but, in proceeding
backward, they diverge, stretch first outward, then

246 Cerehrum.

downward, and lastly forward ; in fact, they descend
into the superior cornua, and there end in bulbous ex-
tremities, called the pedes hippocampi. This descent or
elongation, which may be denominated the crus hippo-
campi, is continuous above with the crus fornicis, but
below it gets to the outward part of the crus fornicis,
and gives off a thin, plaited, medullary border, which
may be said to be an extension of the corpus fimbria-
tum. Their medullary covering appears to be continued
from the corpus callosum ; their internal cortical sub-
stance, which is interspersed with medullary striae, ori-
ginates from the very middle of the hemispheres. If
sliced, they will be found to consist of alternate laminae
of medullary and cortical matter.

Deeply lodged in the channel between the corpus
striatum and hippocampus, lies a red, soft, vascular
substance, consisting of a plexus or collection of minute
blood-vessels, invested in an extension of pia mater,
called the plexus choroides. This plexus first makes its
appearance from behind the fornix ; inferiorly, it ends
abruptly in a round bulbous mass ; superiorly, it sends
down a process into the superior cornu. The arteries
composing it come from the posterior arteries of the
cerebrum : they enter the interior of the brain along a
fissure, which in one place is a complete canal, exist-
ing between the posterior lobes of the cerebrum, and
gain admission into the ventricles around the sides of
* the fornix. Its veins assemble and form a large branch,
the vena Galenij which branch unites with a similar one
coming from the opposite plexus ; the two conjoined
make a single trunk, and that proceeds upward, along
the above mentioned fissure.

The fornix is that part which receives the posterior

Cerebrum. 247

border of the septum lucidum. It is extended, after
the manner of an arch, between the corpora striata be-
low and the heads of the hippocampi above, where it
forms a j miction with the corpus callosum, which it
meets at an acute angle. It has four processes or
crura. The two inferior crura spring from the corpus
albicantium, at the base of the brain ; in their course
forward from which, they approximate and unite into
one main crus or pillar ; thus united, they wind up-
ward, describing an arc, and, as soon as they make
their appearance within the ventricles, constitute the
body of the fornix. The superior crura, which are com-
paratively slender, proceed from the upper end of the
fornix, wind upward and then descend into the superior
eornua of the lateral ventricles, where they grow taper-
ing and at length end in sharp-pointed extremities.
Their anterior or concave edges, which are thin, unat-
tached, and somewhat uneven, have been named the
coipora Jimhriata ; their posterior borders are continu-
ous with the crura hippocampi : along their fimbriated
edges run the lateral processes of the plexus choroides.
The middle part or arch of the fornix is unattached ; but
its superior or broad part is contiguously applied behind
to the thalami, and adheres to them through the inter-
vention of a fine membrane, investing the vessels of the
choroid plexus which are ramifying hereabouts, named
the velum inierpositum : from the circumstance of the
back of the fornix being imprinted by these vessels with
many minute linear grooves, mostly running obliquely,
this surface of it is commonly described as the li/ra,
psalterium, or harp.

Having divided and refiected the fornix, and turned
back the heads of the hippocampi, we bring into view

2

248

Cerebrum.

the thalami nervorum opticoruin. These bodies are also
said to be in the lateral ventricles : more properly
speaking, they form the upper and back parts of those
cavities. They are white, conoid in form, narrow and
approximated inferiorly, where they lie between, and
rather behind, the corpora striata ; broad and directed
opposite ways superiorly ; in front they are opposed to
the fornix, which they in a measure support ; and be-
hind they contract into medullary bands — the tractus
optici, which turn round the crura cerebri to the base of
the brain. Upon these bodies the separate portions of
the plexus choroides unite into a single vascular cord,
which takes its course in. the canal between them,
and makes its exit from the brain in the fissure left
between the posterior lobes of the cerebrum. The
thalami are firmer in their composition than the corpora
striata ; like those bodies however they are cortical
within, thinly striated with medullary matter.

In the groove between the thalamus and corpus stri-
atum, partly covered by the plexus choroides, runs a
conspicuously white, medullary band, designated the
centrum semicirculare geminum, vel t(Bnia semicircularis .

The contiguous parts of the thalami, flattened and
closely applied, are united in one broad circular place
by pulpy cortical matter, which union is called their
commissura mollis.

Immediately behind the fore part of the fornix, runs
transversely a firm medullary cord, which is extended
in a curved direction, on either side, into the substance
of the corpus striatum : this forms a band of connection
between the hemispheres, and takes the name of com-
missura inferior cerebri.

Superiorly, above the commissura mollis, is another

Cerebrum.

249

medullary cord, similar to the one last mentioned, but
shorter and smaller, which is the commissura superior
cerebri.

Just over the commissura inferior, between it and
the commissura mollis, between and in front of the
optic thalami, under the arch of the fornix, is a trian-
gular hole, called the foramen commune inferius. Now,
as the lateral ventricles communicate under the arch of
the fornix it is evident that both of them must open
into this foramen ; and as this foramen leads into the
third ventricle, it follows that this cavity and the lateral
sinuses must reciprocally communicate by means of it.

Between the commissura mollis and the commissura
superior is another foramen, which would also be one of
like communication were it not covered and closed by
the velum interpositum, which is here spread over the
surfaces of the thalami, and traversed by the vessels of
the choroid plexuses.

The third ventricle, as it is called, is nothing more
than the fissure which exists between the thalami, in
consequence of their partial divergence, below and be-
hind the commissura mollis, in the medium line of the
brain. The floor or back part of this narrow oblong
cavity, is constituted of the crura cerebri.

Leading from the inferior part of this ventricle is
the infundibulum, a passage that is small at its com-
mencement, but gradually enlarges to its termination,
which is in a blind extremity, in front of the corpus
albicantium, at the pituatury gland. Superiorly, under
the superior commissure, is a passage leading from this
cavity into the fourth ventricle, the iter a tertio ad
quartum ventriculum, which is situated in the cerebellum.

250 Cerehrum.

Over the third ventricle, deejDly lodged between the
summits of the thalami, above and rather before the
superior commissure, we ^wd. the pineal gland — a little,
conoid, greyish body, marked by a slight depression
along its middle, enveloped in pia mater, which it de-
rives from the vessels of the choroid plexus, and at-
tached by that membrane to the thalami, and the
tubercula quadrigemina, which are placed behind it.
From its base or inferior part proceed two little peduncles
or foot-stalks, which run along the top of the superior
commissure, and are implanted into the crura cerebri.
The structure of this little orsfan remains unknown.
It is possessed of considerable finnness ; it is deeply
reddened and highly vascular within ; but I have not
remarked that it contains earthy matter, as is the case
so frequently with that of the human brain.

Above the third ventricle, behind the pineal gland,
and immediately over the iter a tertio ad quartum ven-
triculum, are four considerable eminences, the tubercula
quadrigemina — or rather higemina, since they are di-
vided into the two nates and two testes. The nates,
the foremost and by much the largest of these bodies,
separated by a groove from the testes, and by a deep
perpendicular fissure from each other, present semi-oval
exteriors, of a mixed composition, cineritious and me-
duUaiy, and are in intimate union with each other and
with the testes. The testes, much smaller than the
nates, are also ovoid in figure^ but their long diameters
are placed contrariwise— transversely. In their com-
position they are alike also, as well as in their connec-
tions, both being joined to the crura cerebri, by which
they are supported.

251

Cerebelliun.

In order to guard against a common misconception
of the relative position of this part, I shall repeat
here what I took occasion to lay some stress upon in a
former lecture* — that the three divisions of the horse's
brain are similarly lodged, in regard to their cranial
case, to what the correspondent parts in man are, but
that when we view them as the animals naturally stand,
their relative situation is altogether altered. The cere-
bellum (as in man) occupies that compartment in the
basis of the cranium which is formed above and be-
hind by the anterior occipital bones, laterally by the
petrous portions of the temporal bones, and superiorly
and anteriorly by the tentorium ; that septum being
deficient inferiorly and anteriorly to give passage to
the crura cerebri to form a junction with the cerebel-
lum, while the vacuity admits also of the projection of
the anterior vermiform process, which is the only portion
of the latter that does not rest upon the tentorium.

In volume, figure, and aspect, the cerebellum is at
once distinguishable from the cerebrum. It is only
one-sixth of the size of the cerebrum. Its figure is
irregular — it has two oval ends, placed transversely,
united in the middle by a broad and prominent vermi-
form belt : its lateral dimension exceeds its longitudinal.
Its aspect is lobular or convoluted ; but it is every-
where so striated with deep transverse fissures that
its appearance is different from any other part of the
organ.

The cerebellum is superficially divided into three ob-
long lobes : — a middle lobes, and two lateral lobe. The

* Part I. Lecture x. p. 145

252

Ceiehelluni.

lateral lobes, which are opposed to the posterior lobes of
the cerebrum, are small and ovoid ; the middle lobe is
prominent, arched, and subdivided into lobuli by several
sulci, conspicuous for their depth, crossing its upper
and under surfaces. The anterior and more prominent
part of this lobe, which is received into the great
fissure of the cerebrum, is denominated the anterior
vermiform process ; the continuation of it, along the
summit of the head, forms posterior vermiform process.

In the cerebellum, the disposition and proportionate
quantities of medullary and cortical matters, are re-
versed, with regard to the cerebrum. Here the cortical
substance exceeds the medullary in quantity, and, in-
stead of forming the outward parts, pervades the inner-
most. Slice the cerebellum horizontally, and these
substances present a laminated appearance ; make a
vertical section of it, and they are so disposed as to
give the surface an arborescent representation, usually
denominated the arbor vita.

Within the cerebellum, or rather between it and the
tuber annulare and medulla oblongata, which last form
its back part, is situated the fourth ventricle. Begin-
ning above the testes, where it is perforated by the iter
a tertio, it extends upward and backward to the extre-
mity of the medulla oblongata, where it ends in a
sharp angular point, which, with a groove running from
it along the floor of the ventricle, anatomists have
resembled to a pen, and thence called the calamus
scriptorius.

Extended across the inferior and anterior part of the
ventricle, closing the cavity between the testes and lower
extremity of the anterior vermiform process, is a mem-
brano-medullary curtain, the vehim vel valvula Vie us-

Poslerioj' Surface of the Brain. 253

SEN 11. It is supported at the sides by two medullary
productions, remarkable for their whiteness, the pro-
cessus a cerebello ad testes, which some regard as the
columns of the valve.

The choroid plexus of the cerebellum is found, lying
crosswise, in the posterior part of the fourth ventricle,
between the cerebellum and medulla oblonofata. It
nowise differs in its composition from the plexuses of the
lateral ventricles. It is distributed into three principal
divisions : one lies in the middle of the calamus ; the
other two, lateral, are lodged in fissures in the cere-
bellum, occupying the spaces between it and the tuber
annulare.

Posterior Surface of the Brain.

The base or posterior part of the cerebrum is divided
into six lobes : two inferior or anterior, and two middle,
which rest upon the alae of the ethmoid bone, and two
superior or posterior, which are lodged in the fossae of
the squamous portions of the temporal bones.

Upon the middle lobes are two broad prominences
w^hose surfaces are remarkable from being perfectly
smooth : these are the bases of the corpora striata, the
parts from which the olfactoiy nerves are seen taking
their origin.

Above these, in the middle of the brain, are two ob-
long medullary eminences intimately united together :
these are the crura cerebri. They rest upon the alas of
the sphenoid bone. They take their rise from the in-
ferior and middle lobes of the cerebrum, and are con-
tinued into an ovoid protuberance above them, named
the tuber annulare. Though medullary without, the

254 Posterior Surface of the Brain.

crus, when cut deeply into, exhibits a cineritious hue,
and the part that is the most darkly shaded has been
called the locus niger.

Seated between the crura is a small, hemispherical,
medullary eminence, distinguished as the corpus albi-
cantium. Tn the human subject this body is double;
and there is some appearance of a depression along its
middle in the horse. It is medullary without, but has
a tinge of cortical matter within.

Winding obliquely downward, around the crura, pro-
ceeding from the terminations of the thalami, are the
tractus optici : they are to be regarded as the roots of the
optic nerves, with which they are continuous. They
are entirely medullary.

Higher up and more outward than the crura cerebri,
are the crura cerebelU — two stout, cylindroid, medullary
cords joining the lateral lobes of the cerebellum to the
tuber annulare. These parts consist of a prolongation
of the medullary substance which forms the trunks of
the arbor vitse.

The tuber annulare vel pons Varolii, whose situa-
tion now I need not point out, may be said to be consti-
tuted of the united substances of the crura cerebri and
crura cerebelli : it is, in fact, the common termination
or medium of junction of the cerebrum and cerebellum.
It is supported by the cuneiform process of the posterior
occipital bone. Its surface is marked by a shallow
depression along its middle, which gives it the appear-
ance of having lateral eminences. Internally, the tuber
exhibits a mixture of cortical and medullary matter.

Above and below the tuber, centrically situated, are
little round depressions or blind holes, which are ge-

Medulla Oblongata, — Pituatury Gland. 255

nerally described as the foramina cava, superior et in-
ferior. They serve as places of lodgment for small
plexuses of blood-vessels.

Still higher than the tuber is placed the

Medulla Oblongata.

The smallest division of the cerebral mass. It rests
upon the cuneiform process of the occipital bone, and
is continued upward and backward to the foramen mag-
num. Regarded in an excised state, it is of an oblong,
quadrilateral figure. It has a deep fissure along its
middle (in which runs the basilar artery) that divides
it into lateral portions. Contiguous to this fissure, ris-
ing from the sides of it, are two longitudinal eminences,
called the Eminenticc pyramidales. From the lateral
parts project two other eminences, named the Eminen-
tice Olivares. The upper surface of the medulla oblon-
gata forms, with the tuber annulare, the floor of the
fourth ventricle. Though, like the tuber annulare, it is
composed internally of a mixture of the cortical and
medullary substances, its shade is lighter than that
body.

Lastly, remains to be considered the

Pituatury Gland.

A REDDISH body, of an ovoid form, seated upon the
sella tursica, within a fold of the dura mater. It has a
membranous capsule, surrounded by cellular adhesions,
by which it is firmly retained in its place, whence it is
not dislodged even though the cerebral mass be taken
out. It has the appearance of being highly vascular ;
it is however of a lighter color internally than externally,
and puts on a mottled aspect in places. — The ancients
entertained a notion that it received a fluid from the

256 Medulla Spinalis.

brain, which they called pituita, through the infundi-
bulum, and transmitted it to the nose ; but we find that
these parts have no communication whatever : in short,
its real use is totally unknown.

Medulla Spinalis.

The spinal marrow is that extended cylinder of brain-
like substance which is continued from the posterior
part of the medulla oblongata through the entire length
of the spinal canal. Lodged within a cavity whose form
is continually undergoing more or less variation, it nei-
ther completely fills nor precisely fits that cavity : in %om&
places it swells in size, in others it grows contracted ;
everywhere it has the appearance of having shrunk from,
or of being disproportionably small for, the canal in
which it is contained.

It is inclosed in the same membranes that envelop
the brain ; but, in addition to them, the superior liga-
ment of the spine serves as a covering and defence to it
below. To this, and to the periosteum lining the canal,
its proper theca is loosely attached by cellular, adipose,
and gelatinous matter. Its dura mater is derived from
that which covers the brain : in being continued through
the foramen magnum the membrane is contracted into
a cylindrical sheath which loosely incases the marrow,
and is generally described under the denomination of
theca vertebralis. About the beginning of the sacrum,
the theca narrows ; it recedes from the sides of the canal,
and, having inclosed the termination of the marrow, is
extended into a point and lost upon the cauda equina.
The dura mater is connected to the membranes under-
neath, the membrana arachnoides and pia mater, by a
fine cellular tissue ; and these coverings have the same
relation to the marrow that the same membranes have to

Medulla ^Spitto/is. 257

the brain, of which they may be considered prolong-
ations.

The spinal marrow, stripped of its membranes, is
cylindroid in form, flattened along its upper and un-
der surfaces, each of which is marked by a longitudi-
nal linear fissure : these fissures, of which the inferior
is the more conspicuous one, are continuations of those
that traverse the medulla oblongata, they equally di-
vide the marrow into two cords, and serve as conve-
nient tracts for the spinal blood-vessels. In places,
also, some transverse fissures or little wrinkles are ap-
parent, which are evidently for the purpose of admit-
ting of certain degrees of elongation and contraction, in
order to guard against extension or laceration of the mar-
row under any motion or altered position of the spine.
The marrow varies in its dimensions at different parts ;
and also somewhat in its form. At its beginning, from
the medulla oblongata, it is large, from which to the
fifth cervical vertebra it gradually grows less in circum-
ference ; here it swells again, but again diminishes in
entering the first dorsal vertebra ; along the back it is
small and nearer approaches the form of a perfect
cylinder ; but in the loins it grows flatter than ever, and,
a third time, increases in size, until it reaches the
last lumbar vertebra, from which it begins to taper, and
continues so to do until it at length ends in a pyra-
midal point within the second piece of the sacrum.
Around its termination come off several large nervous
cords, which are continued along the canal, and ex-
tend, some of them, into the coccyx : altogether
they have been resembled to a horse's tail, and thence
denominated canda equ/na.

In the year 1808 Mr. Sew ell conveyed in a letter

PART III. s

"258 Medulla Spinalis.

to Sir E. Home, which was afterwards read to the
Royal Society, the particulars of what he conceived to
be a canal running from the fourth ventricle through the
whole length of the spinal marrow, containing a limpid
colorless fluid, and lined by the memhrana arachnoides
or a membrane very like it; but, since this, M. Bel-
LENGERi, of the College of Medicine of Turin, has
proved, that this supposed canal is in truth a median
furrow dividing the spinal marrow into six bands ;
he has also shown that the roots of the spinal nerves,
both anterior and posterior, are triple. This discovery
has opened an entirely new field of physiology, and is
leading rapidly to very important results affecting patho-
logy-

The nerves given off by the spinal marrow are twen-
ty-nine pairs. They originate, the same from either
side, by superior and inferior fasciculi or bundles of fila-
ments, which pierce the theca vertebralis in several
places, from which they derive cellular sheaths in their
egress. The cervical and dorsal nerves, for th.e most
part, arise from the marrow opposite to the foramina
through which they make their exit from the spine ;
but the posterior lumbar and sacral nerves proceed
obliquely backward before they turn out ; and some of
the latter, and all the coccygeal nerves, run longitudi-
nally down the canal before they quit it. The filaments
composing the fasciculi are themselves small ; they
bear a proportion in size and number to the nerves of
which they are the roots. Threads of communication
may be seen, oftenest in the neck, running from
one set of fasciculi to another. The superior fasciculi
are separated from those which arise below, by a
, strong, white, fibrous band which runs along the side

Medulla Spiualis. 259

of the marrow, and has a puckered attachment in one
particular place to the theca, between every pair of
nerves, on either side ; inwardly, it is intimately joined
to the pia mater : this band, which is denominated
from its several pointed connections the ligamentum
denticulatum, prevents that injurious extension of the
nerves, when the spine is forcibly flexed, which might
occasion laceration of their medulla. In the space be-
tween the vertebrae, the superior fasciculi converge
and form a ganglion, from the opposite side of which
many filaments arise and proceed with the inferior fasci-
culi and join them, and thus form the trunk of the
nerve.

LECTURE LXVI

Origin and Distribution of the Nerves.

Xt has been observed, in speaking of the nervous sys-
tem in a former lecture, that there are in all forty-six
pairs of nerves : ten coming from the brain, are distin-
guished as the cerebral nerves ; thirty-six from the spi-
nal marrow, denominated the spinal nerves. The nerves,
being symmetrical in number and distribution on either
side of the body, take their origins by pairs, and these
pairs are numbered, and so distinguished from one
another, according to the order in which they arise,
proceeding from below upward within the head, from
before backward within the spine. In addition to this
distinction of ordinal number however, every pair of
cerebral nerves has obtained a particular epithet signi-
ficant of the specific purpose they serve, the part they
supply, or else some peculiarity in their division or
distribution. With these remarks, I shall commence
with the origin and distribution of the

CEREBRAL NERVES.

First Fair or Olfactory Nerves
Arise from the corpora striata, along the posterior

Second Fair or Optic Nerves. 261

borders of which bodies the medullary bands or roots of
them may be traced as high up as the middle lobes of
the cerebrum. These are the largest of the cerebral
nerves, are bulbous at their origin, pulpy in texture,
and exhibit, when cut into, comparatively to their
size, large cavities, which are walled in by a layer of
medullary matter, inclosed within a thinner one of cor-
tical substance. These cavities, which some erro-
neously describe as ventricles of the brain, since they
evidently belong exclusively to these nerves, are conical
m figure : from being capacious inferiorly, and gene-
rally distended with fluid, they contract upward into
small circular canals, which lead throuo-h the trunks
of the nerves into the anterior cornua of the lateral
ventricles. Girard calls them the ethmoidal sinuses;
but, as this would create confusion in our nomencla-
ture, it would be better to name them the olfactorij
sinuses. This, the tubular portion of the nerve, is
sheathed in dura mater. From its abrupt or truncated
termination against the cribriform plate of the ethmoid
bone, are transmitted numerous, soft, nervous fila-
ments, which pierce the foramina of this bony plate,
and enter the nose, where they undergo a further sub-
division, and are at length widely dispersed over the
schneiderian membrane.

Second Pair or Optic Nerves.

If we may be allowed to estimate the importance of
nerves by their magnitude, the optic will hold the
third rank among those of the brain, being exceeded
in size only by the lat and 5th pairs. They take their
roots from the posterior, contracted, and incurvated
parts of the thalami nervorum opticonim. At first

262 Third Pair or Motores Oculorum.

they wind forward and downward, around the crura
cerebri, which radical parts of them have obtained
the name of tractus optici ; in doing this they approach
each other, (in which relative course they are singular,
all other pairs diverging) and at length form a junction
— an intermixture, some say a decussation, of their fibres,
(in which they are also singular) just below the corpus
albicantium. Then, they become again two separate
nerves, proceed downward and forward through the
foramina optica, and enter the cavities of the orbits.
Here each nerve continues this oblique course, sur-
rounded by the muscles of the eye, and penetrates the
inner, inferior, and posterior part of the eyeball, with-
in the interior of which it expands and forms the re-
tina. In its whole course, it is inclosed within a
sheath prolonged from the dura mater, forming one
more peculiarity in its distribution.

Third Pair or Motores Oculorum

Take their origin, by several filaments, from the in-
ward parts of the crura cerebri, about their middle.
The trunk of the nerve, thus formed, first runs obliquely
outward, across the back of the crus, then turns down-
ward and enters the cavernous sinus, wherein it is
covered by a sheath of dura mater, and continues its
course through the foramen lacerum orbitale, inwardly
placed to the other nerves, into the orbit. In entering
the cavity, the nerve divides into two branches. The
smaller is generally received by a single muscle— the
levator oculi. The larger branch subdivides into seve-
ral others : the longest of these runs round the eye-ball
and penetrates the obliquus inferior ; the two or three
others run to the adductor and depressor muscles.

Fourth Pair or Pathetic— Fifth ' 263

Upon the outward side of the optic nerve, between it
and that part of the motor ocuH horn which the branch
nerves spring, is situated the opthalmic ganglion.
This little body is principally constituted of branches
from the third pair ; but it also receives a filament or
two from the sixth. The nervous threads transmitted
by the ganglion surround the sheath of the optic nerve,
and pursue their course over it, penetrate the globe of
the eye, and run to be dispersed upon the iris.

Fourth Pair or Pathetic.

Thesk, the slenderest of the cerebral nerves, take a
filamentous origin from the summits of the testes,
whence they proceed outward between those bodies
and the crura cerebelli, creep round the crura cerebri,
and are seen at the border of the tentorium entering the
cavernous sinus. Having coursed the anterior boun-
dary of the sinus encased in dura mater, it takes re-
fuge again in a small bony canal, constructed for its
passage, in front and rather to the outward side of the
foramen lacerum, which conducts it into the orbit. Its
destination is the superior oblique muscle of the eye,
to which it exclusively distributes its ramifications.

Fifth Pair or Par Trigerniiium.

These are the largest nerves of the brain. They
take their beginning by a multitude of filaments from
the crura cerebelli, and forthwith run for security into
the cavernous sinuses, where they are covered and pro-
tected by distinct sheaths of dura mater. Each nerve
within the sinus suddenly swells in bulk, and thus is
said to form a ganglion : and certainly the enlargement
is darker-colored than the nerve itself, but, it does not

264 Fy^f^ Pi'^'' i^^'' Trigemmum.

put on the common appearance of, nor is it of the
same texture as, those little knots or swellings in other
parts which we are in the habit of calling ganglia.
Waving this remark however, and considering it as a
ganglion, we say that three nerves depart from it ; and
these we denominate, from the parts which they are
principally destined to supply, the opthalmic, the an-
terior maxillary, and \he posterior maxillary nerve.

The opthalmic nerve, the smallest of the three
divisions, proceeds for a short M'ay down the sinus in
union with the superior maxillary ; inclining fomard
however it soon leaves that nerve, and takes its passage
through the foramen lacerum orbitale into the orbit.
As it emerges from this opening it splits into three
branches : — the lachrymal, the supra-orbitar, and the
lateral nasal branch.

The lachrymal branch, at its origin, comprehends
two divisions. One is a long single nerve that ascends
behind the muscles of the eye, through the fatty matter
at the bottom of the orbit, winds over the angle formed
between the zygoma and the frontal orbital process, and
ends in subcutaneous and anastomosing branches about
the forehead. The other consists of several filaments
which run forward over the fatty matter enveloping the
eye, and are distributed to the lachrymal gland, con-
junctiva, and ciliary glands of the upper eyelid.

The supra-orbitar brunch takes the same superficial
course across the roof of the orbit to the inner angle of
the orbitar ridge, where it passes through the foramen
supra-orbitarium, and afterwards ramifies upon the skin
covering the forehead. It gives off a twig or two to the
adipose matter of the eye, and sends a branch to the
upper lid.

Fifth Fair or Par Trigcmimon. 265

The lateral nasal branch, the largest of the three,
makes a sudden turn inward, and runs between the le-
vator and retractor oculi, and after having detached a
considerable branch to the membrana nictitans, it en-
ters again the cavity of the cranium through the fora-
men orbitale internum, from which it takes its passage,
by one of the holes in the cribriform plate, into the
chamber of the nose. Herein, it creeps along the top
of the anterior turbinated bone within a bony and mem-
branous canal, immediately covered by the more pro-
minent part of the os nasi, and sends its ultimate
branches to the false nostril and wino; of the nose.
Near its origin, this nerve sends a fine filament or two
to the opthalmic ganglion.

The second division or anterior maiiUary nerve,
much larger than the opthalmic, leaves the cranium
through the foramen rotundum of the sphenoid bone, and
takes its passage through the canalis infra-orbitarius,
whence it emerges, covered by the levator labii supe-
rioris, upon the face : here it splits into several large
branches, denominated the facial nerves ; or, altogether,
from their being imagined to sprout from the trunk
after the manner of the claws of the foot of a goose,
the pes anserinus. But, prior to its entering this
canal, it detaches several branches of importance.
1. A branch which pursues the same course, along the
floor of the orbit, to the inner c anthus, where it sends
filaments to the under eye-lid and lachrymal duct, and
disperses its remaining ramifications upon the contiguous
skin. 2. Several long filaments which descend upon
the tuberosity of the anterior maxilla, penetrate the
bone, and furnish twigs to the antrum and the two su-
perior molar teeth. 3. The largest branch is the spheno-

266 Fifth Pair or Par Trigeminum.

palatine or lateral nasal nerve, to which the foramen
spheno-palatiiium ^ives passage into the nose, wherein
it divides into two sets of filaments. One of these fas-
ciculi is spread over the lateral parietes of the nasal
cavity ; the other ramifies over the sinuses, and trans-
mits a filament of considerable length along the pos-
terior border of the septum which passes through the
foramen incisivum superius to the roof of the mouth.

4. A slender branch which goes to the velum palati.

5. The palato-maxillary nerve is a considerable branch
which traverses the canal of that name in company with
the palatine blood-vessels, and disperses the majority
of its ramifications over the soft palate ; though some
of its longer ones may be followed through the foramen
incisivum inferius into the upper lip.

The terminating or facial branches of this division,
which remain to be described, in general comprehend,
at their exit from the foramen infra-orbitarium, two
large and two small nerves. The principal branch de-
scends in a straight line upon the side of the face, and,
about midway between the foramen and front of the
hp, shoots forth into many smaller branches, which are
dispersed over the side and surrounding border of the up-
per lip. These nerves recieive communicating filaments
from the anterior facial branch of the portio dura, and
with them form an intricate and important plexus upon
the fore and lateral parts of the face. The branch next
in size to this takes a similar course, anteriorly to the
last, and distributes its ramifications to the nares and
muscles clothing them externally. It detaches one
long filament which turns round the smooth crescentic
border of the anterior maxillary bone, and goes to
the muscles internally situated. One of the small

Fifth Pair or Par Trigeminum. 267

branches, which takes its course anteriorly to all the
others, runs directly to the levator labii superioris.
The smallest branch of the four is one of conniiunication
with the portio dura.

The third division, the posterior maxillary nerve,
the largest of the three, leaves the cranium through the
lowermost nook in the foramen lacerum basis cranii, and
runs forward, defended by the branch of the posterior
jaw, across the middle of the pterygoideus, and enters
the foramen maxillare anterius. Its branches are — 1.
A reflected branch which runs up in front of the parotid
gland and joins the portio dura as the latter turns round
the border of the masseter. 2. The buccal nerve,
which pierces the superior portion of the pterygoideus,
crosses behind the tuberosity of the superior maxilla,
penetrates the buccinator, and buries itself in the sub-
stance of the cheek, through which it may be traced
into the lower lip. 3. Twigs to the pterygoideus. 4.
The gustatory nerve, a branch nearly equal in size to the
trunk itself. This, which by itself may be considered
as a trunk, and one of importance too, descends by the
side of the tongue, penetrates that organ about its mid-
dle, and vanishes in its tip. a. Its first branch is a long
one that takes the same direction as the main (maxil-
lary) trunk, and enters a medullary foramen in the
branch of the jaw. b. The gustatory then gives off the
dental, a long slender nerve which courses the side of
the posterior maxilla, concealed by the submaxillary
gland to which it sends twigs, as far as the symphysis,
where it enters a small foramen and sends its ultimate
ramifications to the roots of the incisive teeth, c.
Many twigs which are detached laterally by the nerve as
it courses the substance of the tongue : t^ey take an

268 Seventh Fair or Auditory Nerves,

oblique direction, and are destined for the supply of the
gustatory papilla?.

The posterior maxillary nerve itself, having entered
the interior of the bone, takes a longitudinal course
close to the roots of the teeth, into the fangs of which
it detaches branches as it passes them, while others ra-
mify in the diploe. Through the foramen maxillare an-
terius, the remaining portion of this nerve emerges from
its bony conduit, and then splits into two branches ;
of which the anterior subdivides into several smaller
ones which ramify upon the integument of the under
lip ; the posterior runs for some way without giving off
a single twig, it then ends in four or five long filaments
which expend their ramifications in the interior of the
lip.

Sixth Pair or Abducent es
Arise, by means of filaments, from the medulla ob-
longata, by the side of the fissure along its middle, near
to its junction with the tuber annulare. This nerve
penetrates the cavernous sinus behind the fifth pair,
and therein, running between them and the carotid ar-
tery, it meets with the opthalmic nerve and accompanies
it through the foramen lacerum into the orbit. Here,
it gives off two or three filaments to the retractor
oculi ; but its principal destination is to the abductor,
among the fasciculi of which its ramifications are
equally distributed.

Seventh Pair or Auditory Nerves.

This pair includes two separate nerves on either
side : one, from its remarkable softness, is denominated
the portio mollis ; the other, in contra-distinction, the
portio dura.

3

Seventh Fair or AuflUory Serves. '2C)[i

The pobtio mollis takes its rise from the floor of
the fourth ventricle, by the side of the crena of the
calamus scriptorius. It turns round the medulla ob-
longata, and then passes directly outward and enters
the foramen auditorium internum. Having gained ad-
mission into the vestibule of the internal ear, it resolves
itself into divers pulpy filaments which pierce a perfo-
rated bony plate, and ramify over the various parts of
the labyrinth

The PORTio dura arises from the place of union
of the medulla oblongata, tuber annulare, and crus
cerebelli ; and takes its passage through the foramen
auditorium internum, inclosed in the same sheath of
dura mater with the portiom ollis. At the bottom of
the meatus auditorius internus, it detaches two slender
but important branches. 1. The chorda timpani, a
long slender filament which proceeds into the cavity of
the tympanum, crosses therein the neck of the malleus,
makes its exit again by a small foramen, and, descend-
ing to the root of the tongue, forms a remarkable
union with the lingual nerve. 2. The other also runs
in the vicinity of the tympanum, but then it pur-
sues afterwards the course of the Eustachian tube.
Deeply seated under the os temporis within the fauces
at its exit, its branches become distributed over the
parts in the immediate vicinity.

The portio dura then departs from the internal ear,
issuing from the bone by the spiral canal, deeply bu-
ried under the parotid gland, and gives off the auricular
nerves, of which there are three principal divisions.
1. The anterior auricular nerve ascends over the fleshy
root of the anterior part of the ear, w^here it detaches
some branches which unite with others coming from

270 Seventh Pair or Auditory Nerves.

the lachrymal branch of the first division of the fifth
pair and form a sort of plexus — the anterior auricular
plexus. Its remaining branches are dispersed upon the
skin thereabouts. 2. The posterior auricular nerve, less
in size, mounts the back of the ear, in company with
the blood-vessels, distributing branches to the muscle
about its root, and ending in vanishing ramifications
upon the skin of the ear. 3. The internal auricular,
the least considerable of the three, enters the concha
for the supply of the inward parts of the external ear.
4. Parotideal branches, two, three, or four in number,
ramifying within the substance of the gland, and trans-
mitting other smaller filaments to the covering skin.
Against the articulation of the posterior jaw, the portio
dura is joined by a considerable branch from the pos-
terior maxillary nerve. Augmented in size by this
union, the portio dura emerges from the substance of
the gland, and turns round the cervix of the jaw along
the outward side of the temporal artery. Having
mounted upon the masseter it divides into two princi-
pal branches. The posterior one obliquely crosses the
muscle, a little anteriorly to its middle, enveloped in
cellular membrane, detaching many filaments in its
passage to the fibres of the muscle, but more and larger
ones to the skin, and some few of communication with
the anterior branch, and then ramifies subcutaneously
upon the muscles of the lower lip, and upon the side
of the lower jaw. The ajiterior branch descends over
the fore part of the masseter, a little posteriorly to the
zygoma, likewise clothed in cellular substance, furnish-
ing in its course muscular, cutaneous, and communi-
cating filaments ; having left the masseter, it inclines
forward, undiminished in size from the ramifications it

Eighth Pair or Par Vagum. '27 1

has already produced, and shortly after ends hi an
arborescent expansion over the inferior and anterior
part of the face. It sends some filaments to the mus-
cles thereabouts, and to the upper lip ; but its principal
ramifications go to join those of the anterior maxillary
nerve.

Eighth Pair or Par Vagum.

This pair is constituted of two nerves on either side,
so that it may be said to be double : — the accessory or
additional one is denominated the glosso-pharyngeiis,
the other is the proper par vagum. They arise by
many filaments from the corpora olivaria, and make
their exit through the foramina lacera basis cranii, in
company with the nerves next to be described. Having
left the skull, we find them lodged, secure from injury,
with the nerve of the ninth pair, in a hollow space
to the inward side of the condyloid process of the
occiput.

The glosso-pharyngeus, by much the smaller of the
two, ndw quits the par vagum, and, turning round the
internal carotid artery, runs forward and downward
upon the side of the pharynx, insinuating itself among
the constrictor fibres, whence it proceeds to the root of
the tongue and there disappears. Its branches are —
1. At its origin, a reflected branch which joins the
portio dura just before that nerve pierces the parotid
gland. 2. Two branches to the constrictors of the
pharynx. 3. Before it reaches the tongue, the nerve
splits into three or four branches which ramify and
vanish in the base or root of that organ.

The proper par vagum, having disunited from the
glosso-pharyngeal nerve, proceeds downward and back-
ward to join the carotid artery, in the same cellular

272 Eighth Pair or Par Vagum.

sheath witli which, to the outward side of the vessel,
it takes its course along the neck to the chest. Its
cervical branches are — 1. Two or three fine filaments
to the superior cervical ganglion. 2. The pharyngeal
branch, which is reflected upon the side of the pharynx :
whose filaments are — a. To the esophagus, b. One
received from the sympathetic, c. The continuation of
the nerve, which is expended in the substance of the
pharynx. 3. Two slender branches to the carotid ar-
tery, upon the coats of which they ramify, unite, and
ultimately split into twigs which form a sort of plexus
around the vessel at its bifurcation, from which other
filaments are sent along the parietes both of the exter-
nal and internal carotids. 4. The laryngeal branch,
which crosses above the carotid artery, then winds
downward upon the side of the pharynx, in its way to the
larynx, and enters a perforation through the posterior
ala of the thyroid cartilage.

At the posterior part of the neck the par vagum in-
clines upward, and is found above the carotid artery,
between which vessel and the axillary artery it con-
tinues its course, through the space between the two
first ribs, into the chest. Having entered the thoracic
cavity it runs within the superior mediastinum ; but it
has a somewhat different relative situation on one side
from what it has on the other : the right nerve adheres
in its passage to the side of the trachea, crosses above
the root of the right lung, alongside of the esophagus,
and gains the under surface of that tube before it leaves
the chest ; whereas, on the left side, the nerve accom-
panies the anterior aorta, and crosses the root of the
posterior aorta to reach the esophagus, to the left and
upper side of which it pursues its course as far as the
the diaphragm.

Eiohth Put/ or Par TV/ov////. 273

Its brandies within the chest are — 1. Filaments to
tlie tracheal plexus, which consists of an assemblage and
intercommunication of nerves, mostly from the sympa-
thetic, around the lower part of the trachea, within the
space between the two first ribs. 2. Two or three
smaller branches to the cardiac plexus. 3. A single
branch, of considerable importance, denominated the
recurrent nerve. 4. Branches to the anterior pulmonary
plexus. 5. Reflected branches to the posterior pul-
monary plexus. And, on the right side, in addition to
these, the nerve furnishes a still larger branch which is
directed forthwith to the heart; in its passage however
it subdivides into two cords, and these branch out as
they approach the base of the organ, and penetrate the
parietes of the auricles.

The recurrent nerve of the left side originates from
the par vagum by the side of the anterior aorta, and
coils round the root of the posterior aorta, including
that vessel in a sling as it were ; but, on the right side,
it leaves the trunk as the latter passes the first rib,
winding forward within the angle formed between the
anterior aorta and its first large branch — the posterior
cervical artery. The recurrent nerve, so denominated
from its retrograde course, then takes the first part
of its reflected passage above and outwardly to the
par vagum ; by degrees however in running up the
neck it approaches the trunk, gains the inner side of it,
and along the anterior half of the neck is found be-
tween the carotid artery and the trachea. Having
reached the top of the air-tube, it spreads into many
fine terminatino- branches, several of which run to the
muscles of the larynx, though the principal of them
creep along the sides of the thyroid cartilage and end

PART III. T

274 Eighth Fair or Far Vagum.

in ramifications upon the membrane of" the glottis. Its
branches are — 1. Filaments to the pulmonary plexus ;
and, on the left side, some also to the cardiac plexus.
2. Filaments to the posterior cervical ganglion. 3.
Long slender branches both to the esophagus and tra-
chea in its passage up the neck.

The pulmonary plexuses, hiferior and superior,
consist of networks of nervous filaments, some of which
are of large size, surrounding the great vessels constitut-
ing the roots of the lungs. They are composed of
branches and threads of nerves from the par vagum and
recurrent of one side, and of similar ramifications from
the opposite side : the inferior plexus clings to the tra-
chea at its division, and spreads under the bronchiffi
and pulmonary vessels ; the superior, which receives
several reflected branches from the par vagum, lies be-
hind the roots of the lungs, and is less considerable
than the inferior. From these plexuses the numerous
iiervous filaments are derived which cling to the rami-
fications of the bronchife and pulmonary vessels for
the supply of the parenchymatous and vascular struc-
tures and lining membrane of the lungs. — Moreover
the pars vagum, in the chest, detaches many twigs to
the esophagus, which interlace its muscular coat by
uniting with others from the opposite nerve : in this
manner another plexus is produced which is named the
esophageal.

The par vagum having entered the abdomen, cling-
ing to the sides of the esophagus, the nerve on one
side is differently distributed to that on the other.
They both run to the stomach ; but the left nerve,
prior to reaching it, divides into two sets of branches.
One of these pursue their course backward and spread

Accessory Nerves to the Eight Pair. 275

over tlie upper part of the organ, sending filaments to
the cardia, and others along the small curvature which
communicate with the ramifications of the right nerve ;
the other crosses above the stomach to the left side,
taking the course of the gastric artery, and joins the
great semilunar ganglion. The right nerve, smaller
than the left, as soon as it reaches the cardia, splits
into many branches which traverse the small curvature,
where they form communications with the left, and
spread their ramifications upon the under part of the
organ : some of them run to the pylorus also, and
others go to join the hepatic plexus.

Accessoj\y Nerves to the Eight Pair. i

These nerves are considered as accessory to the for-
mer in consequence of their being found in close con-
nection in issuing from the cranium. The accessory
nerve itself is formed within the vertebral canal,
by the concurrence and union of several filaments de-
rived from the side of the medulla spinalis, one or two
of which may generally be traced down to the place of
origin of the fourth or fifth cervical nerve. In its course
into the head it receives many other fine threads from
the marrow, and in the cranial cavity joins the par va-
gum, with which and with the nervus glosso-pharyn-
2:eus, all inclosed in one and the same sheath, it de-
scenda through the foramen lacerum basis cranii. Be-
neath the atlas, the accessory nerve leaves its compa-
nions and sphts into two divisions. — The anterior di-
vision runs downward and forward, and penetrates the
belly of the sterno-maxillaris, among the fasciculi of
which it may be followed, transmitting numerous lateral
twigs in its course, down to the very origin of the mus-

T 2

276 ISlmth Pair or Lingnaks.

cle. The posterior division turns round the transverse
process of the atlas, and takes a waving course between
the levator humeri and splenius, obliquely across the
side of the neck to the top of the scapula ; where it
plunges into the rhomboideus brevis, and vanishes in the
muscular substance. This division receives filaments
of communication from several of the cervical nerves,
and furnishes ramifications to the muscles over which
it passes.— The branches of the trunk of the accessory
nerve are— 1. To the par vagum, at its exit from the
skull. 2. Some small filaments to the anterior cervical
ganglion. 3. A filament of communication with the
sub-occipital nerve.

Ninth Pair or Linguales

Arise, behind the eight pair, from the corpora oli-
varia, pass out of the cranium through the foramina
condyloidea anteriora, and are first found, in company
with the par vagum, against the inward sides of the coro-
noid processes. This nerve takes its course obliquely
downward, along the branch of the lower jaw, runs
between the pterygoideus and the larynx, and then insi-
nuates itself between the muscles forming the root of the
tongue. Having penetrated the substance of this organ,
the nerve pervades its middle, accompanied by the lin-
gual artery, and ends in a ramous expansion in its tip.
The branches of this nerve are — 1. Some small ones in
its course, to the hyo-glossus longus ; one of which,
remarkable for its length, runs to the termination of
that muscle, detaching many filaments in its way. 2.
Lateral branches, which come off in a half penniform
manner, within the substance of the tongue, and ramify
extensively among the fibres of the other lingual muscles.

LECTURE LXVII.

In the last lecture I gave the anatomy of those
nerves which may be said properly to belong to the
head : the nerve next to be described is one that di-
vides its branches, pretty equally, between the head
and the neck.

The Sub-occipital Nei"ce,

By some writers considered as the first of the cervical
nerves, has a filamentous origin from the place of junc-
tion of the medulla oblongata with the medulla spinalis,
and passes out through a foramen in the anterior part
of the body of the atlas. It then splits into a superior
and an inferior division. The superior division, larger
than the inferior, we find deeply buried in muscle upon
the transverse process of the atlas, where it spreads
into several small branches, of which two only are
worthy of remark, the others being quickly expended
in the contiguous muscles. One of these is a deep
muscular branch, which penetrates the mass of muscle
upon the occiput ; the other ascends over the vertex,
and ramifies upon the inward and back part of the ear.

The inferior branch, the longer one, turns round the
transverse process of the atlas, and runs through a fo-

278 Cervical Nerves. — First Cervical Nerve.

ramen in the anterior wing of it ; it then winds down
towards the windpipe, and transmits its ultimate ra-
mifications to the thyroid gland, summit of the tra-
chea, and some lymphatic glands thereabouts, and
to the sterno-maxillaris and sterno-thyro-hyoideus.
Its filaments are — a. Some to the deep-seated muscles
in front of the atlas, b. Two or three to the anterior
cervical -ganglion, c. One of communication with the
lingual nerve.

Cervical Nerves.

I HAVE already shown in what manner these nerves,
which consist of seven pairs, originate from the cervi-
cal portion of the spinal marrow, and how they pass
out on either side, through the foramina which are
formed by the articulation of the vertebrae : I may add
here, that each pair of nerves are numbered, by way
of distinction, after the vertebra immediately behind
which they make their exit ; and that every nerve, as
soon as it has issued from the spinal canal, becomes di-
vided into a superior and an iriferim- fasciculus, which
are directed to the correspondent parts of the neck.

First Cervical Nerve

Makes its exit from the spinal canal by that larg,e
intervertebral gap which exists between the atlas and
vertebra dentata. The superior fasciculus of it consists
of several branches ; I shall only notice one however
which is larger and longer than any of the others, all
of which soon penetrate the contiguous deep-seated mus-
cles. This branch is reflected backward upon the side
of the second vertebra, and is continued obliquely up-
ward under the complexus, to which muscle its ramifi-

Second Cervical Nei-ve.

279

cations are distributed. It sends backward a ramus of
communication to the second cervical nerve. — 'The in-
ferior fasciculus is composed of two principal branches.
The superior branch, more considerable than the in-
ferior, turns forward and becomes superficial. It crosses
the transverse process of the atlas, and there sends a
subcutaneous ramification along the panniculus, to the
angle of the jaw. The main branch is then continued
upward, detaches another — a posterior ramification to
the panniculus, and ascends to the root of the ear ; here
it ends in several small branches, the shorter of which
supply the muscles of .that part, while the longer creep
up the concha and ramify upon its outw^ard surface.
In its course, it communicates with the accessory nerve.
The inferior branch passes downward and forward upon
the longus colli, to which it sends filaments, leaves
that muscle to ramify in the levator humeri, and ulti-
mately disappears among the fibres of the panniculus.
This branch has also a communication with the

Second Cervical Nerve.

This is a nerve whose distribution is involved in a de-
gree of complexity in consequence the number and di-
versity of its ramifications. The superior fasciculus in-
cludes three or four branches of considerable size. 1.
Is found ramifying over the inward surface of the splenius.
2. Runs to the spinalis colli. 3. To the complexus. 4.
To the first cervical nerve, and to the complexus minor,
extending to the occiput.- — The inferior fasciculus fur-
nishes mostly superficial branches. 1. One turns for-
ward and communicates with the accessory nerve. 2.
Winds backward and ramifies superficially over the
splenius. 3. Pierces the levator humeri, and expends

t

280 Third and Fourth Cervical Nerves.

itself in subcutaneous ramifications. 4. Creeps along
the under surface of the levator humeri, sending off
one or two long subcutaneous filaments. 5. Is a fila-
ment of communication with the

Third Cervical Nerve.

This is also a nerve whose muscular branches are
numerous and intricate. The superior fasciculus is split
at its exit into several large and some small branches.
1. Some short twigs to the spinalis colli. 2. A large
branch to the splenius. 3. and 4. Long winding
branches, which run upon the ligamentum subflavum
and vanish in the substance of the complexus. 5. A
single branch to the spinalis colli. — 7'Ae inferior fasci-
culus is composed of two principal branches. The in-
ferior branch turns round the articulation formed be-
tween the third and fourth vertebrae, and spreads its ra-
mifications upon the longus colli. The superior branch
winds upward for a short way, and subdivides into three
smaller ones, of which two run to the levator humeri,
and the third pierces that muscle and ends in subcuta-
neous ramifications : from one of the former branches
a filament of communication runs to the

Fourth Cervical Nerve.

Its superior fasciculus turns round the vertebrae and
separates into three or four large branches which sup-
ply the contiguous parts of the spinalis colli, splenius,
and complexus.— r/ic inferior fasciculus, the more con-
siderable and important one, gives off at its origin some
twigs to the longus colli ; it then runs down a short
distance and detaches — 1. A large branch to the sple-
nius. 2. A small one to the lonirus colli. 3. A lon<^-

Fifth and Sixth Ccrviml Nerves. 281

filament which passes backward, covered by the levator
humeri, to assist in composing the phrenic nerve. 4.
Several long terminating branches, which may be traced
upon the levator humeri, over the point of the shoulder.
This nerve communicates with the fifth cervical by a
small circumflex filament, and sends a considerable
branch backward which also joins it.

Fifth Cervical Nerve

Makes its appearance between the fifth and sixth
vertebra). Its superior fasciculus forms a set of deep
muscular branches which are mostly destined to the
spleniiis. The inferior fasciculus comprehends three
principal branches. 1. Runs to the point of the
shoulder, where its ramifications are principally ex-
pended in the levator humeri : at its origin it sends a
twig to the longus colli. 2. A large branch to the ser-
ratus magnus. 3. The most important of the three,
takes a deep-seated course to the point of the shoulder :
there it sends off — a. A small branch to the phrenic
nerve. 0. One of communication to the sixth cervical
nerve, c. One that descends obliquely outward to con-
tribute to the formation of the humeral plexus.

Sixth Cervical Nerve

At its exit, divides. The superior fasciculus, com-
paratively small, turns round the articulation, runs up-
ward and penetrates the serratus magnus. — The iiferior
fasciculus, remarkable for the number and large size of
its branches, passes backward under the transverse pro-
cess of the seventh vertebra. It furnishes — 1. Some
twigs to the longus colli. 2. A long filament to the
posterior cervical ganglion. 3. A filament to the phrenic

282 Seventh Cervical ami Diaphragmatic Nerves.

nerve. 4. Large branches running to the formation of
the humeral plexus.

Seventh Cervical Nerve.

The last of these nerves comes out between the
seventh cervical vertebra and the first dorsal. Its supe-
rior fasciculus, very inconsiderable, consists only of a
small branch which is expended in the serratus mag-
nus. — The inferior fasciculus comprises a large, flat
nerve, which is directed backward to join the humeral
plexus. In its way it forms a broad union with the
first of the dorsal nerves, and detaches a branch to the
sympathetic nerve.

The Diaphragmatic or Phrenic Nerve,

Principally formed by the union of branches from
the fifth and sixth cervical nerves, and generally by the
addition of a small filament from the fourth, takes a
solitary course down the neck, along the inferior border
of the scalenus, enters the chest just above the root of
the axillaiy artery, and traverses the side of the peri-
cardium to reach the tendinous centre of the diaphragm,
where it is divided and spread out into many divergent
ramifications.

Dorsal Nerves.
Of these nerves there are eighteen pairs. In issuing
from the marrow they are directed obliquely backward.
Like the cervical nerves, they are regularly numbered
in succession ; and present, at their exit, superior and
inferior branches ; but these branches are less in size,
and evolve fewer ramifications. The inferior branches,
commonly called the intercostal nerves, run, in company

Dorsal Nerves.

283

with the intercostal blood-vessels, along shallow furrows
in the posterior edges of the ribs, between the internal
and external intercostal muscles, and direct tlieir
course to the sternum.

The superior branches turn immediately upward be-
tween the transverse processes, pierce the intercostal
I muscles and mount upon the back ; here they proceed
obliquely upward, deeply buried in muscle, at lenglli
grow very small and become superficial, and end in
subcutaneous ramifications upon the faschia of the
back. These nerves grow smaller as they are given off
more posteriorly. The anterior divisions of them fur-
nish branches to the muscles of the dorso-scapular
region ; the middle and posterior, to the muscles of the
dorsal region : the hinder nerves also send a few fila-
ments to the loins.

The intercostal nekves require that we enter
a little into particulars. The

First nerve is of large size, and its principal portion
is destined to the humeral plexus. The proper inter-
costal nerve is but a slender branch. It is remarkable
for its solitary course : the other intercostals, for the
most part, accompany the intercostal vessels, whereas
this maintains a middle course between the first and
second ribs, and ramifies upon their lower extremities.
It is also distinguishable from all others but the second,
in not furnishing any cutaneous ramification.

The second nerve detaches, near its origin, a consi-
derable branch which describes an arch downward in its
course over the belly of the longus colli, and afterwards
joins the first nerve. Its intercostal branch, which
is rather larger than the first intercostal nerve, runs for
some distance along the muscular space, and then

4

284 Dorsal Nerves.

accompanies the intercostal blood-vessels, and, like the
first, ends in ramifications near the sternum.

The third, fourth, fifth, sixth, and seventh intercostal
nerves, furnish, each of them, a long cutaneous filament
which ramifies among those muscles of the costal re-
gion exterior to the ribs ; they then pursue their course
downward, incline forward between the cartilages, and
expend their extreme ramifications among the muscles
of the sternal region.- — The other intercostal nerves,
with the exception of the last, having reached the lower
ends of the ribs, do not continue their course between
the cartilages, but quit the intercostal spaces and tra-
verse the under surfaces of the cartilages to the mus-
cular parietes of the abdomen, where we find them
pursuing their way in parellel lines, nearly at equal
distances from one another, between the transverse and
internal oblique muscles, to the rectus, in the substance
of which they branch out and are lost. From the
thirteenth nerve, and from each of those posterior to it,
before they leave the intercostal spaces, comes off a
large cutaneous branch, which, deviating from the con-
tinuation of the trunk, takes an oblique direction
backward, and ramifies extensively upon the aponeuro-
sis of the external oblique muscle.

The eighteenth or last intercostal nerve forms an ex-
ception to this general description. It quits the last
rib at its origin, and stretches obliquely backward,
passing close under the extremity of the first lum-
bar transverse process. Soon after this it splits into
two branches : the smaller one, which is directed back-
vt^ard across the abdomen, at first passes between the
external and internal oblique muscles, but afterwards
insinuates itself among the fibres of the former, and

1

humhar Nerves.

285

ends in subcutaneous ramifications ; the laroev one
traverees the flank and extends for a considerable way
between the internal oblique and transverse muscles.

Lumbar Nei'ves

Correspond in number to that of the lumbar ver-
tebrce. They issue through the spinal foramina in the
loins, and are, at their exit, distinguishable into supe-
rior and inferior divisions. T/ie superior divisions^ of
minor importance, are reflected upward and sent into
that mass of muscle which forms the loin ; and having
distributed the majority of their branches to it, they
pierce the faschia lumborum and terminate in sub-
cutaneous filaments. The inferior divisions require to
be distinctly considered.

The first nerve runs obliquely across the transverse
process of the second vertebra, under the sacro-lum-
balis, and at the end of the third transverse process
divides into two branches. The inner one makes di-
rectly for the anterior spine of the ilium, over which it
passes, and disperses its last filaments in an arbores-
cent manner upon the iliacus, covered by its faschia.
The outer branch takes a sweep outward, between the
external and internal oblique muscles, around the spine
of the ileum, and extends along the anterior border of
the tensor vaginae nearly to the stifle, and there ends
in subcutaneous ramifications upon the faschia lata.
Its other branches are — 1. To the last dorsal nerve.
2. To the sympathetic. 3. To the second lumbar
nerve.

The second nerve, though generally double from its
origin, is smaller than the first. It has communica-
tions with the first nerve and sympathetic, and sends

286 Sacral Nerves.

back a small branch to the formation of the crural
nerve. It also sends twigs to the psoae. Its principal
divisions are two. One is stretched along the iliacus
outwardly, and continues its passage along the fore
part of the haunch, where it becomes subcutaneous and
ramifies over the stifle. The other division crosses
the ilio-lumbar artery, just below its origin, and takes
nearly a similar course to the inward part of the haunch,
where it disperses its ramifications upon the skin and
faschia : in its way, it detaches a considerable branch
— the spermaticus exfermis, which passes through the
abdominal ring, and sends twigs, in the male, to the
scrotum, and a filament along the cord to the testicle j
in the female, filaments go from it to the uterus, udder,
and external labia.

third nerve is almost wholly consumed in forming
the crural nerve. It sends a small branch to the sym-
pathetic, another to the psoas, and a third backward to
the obturator nerve.

The fourth nei-ve detaches a filament of communica-
tion to the sympathetic, and then joins the others in
contributing to the production of the crural nerve ; but
it also sends a considerable branch to the obturator
nerve.

The fifth nerve communicates with the sympathetic,
and then subdivides into three considerable branches :
one contributes to the formation of the craral, another
goes to the obturator, and a third splits and sends one
portion to the gluteal but a much larger one to the
sciatic nerve.

Sacral Nerves.
Of these nerves we reckon five pairs. The anterior

Coccifgeal, Nen^es. 287

nerves are of very large size ; the two last are much
diminished in volume : they all take an oblique di-
rection backward, and traverse the lateral parietes of
the pelvis.

To facilitate their description, we may consider
these nerves also as consisting of superior and inferior
fasciculi.

The superior fasciculi make their exit through distinct
foramina upon the upper part of the sacrum, and are
there buried under a thick mass of muscle : a few fila-
ments from them pierce the faschia above and become
subcutaneous, and hence extend and ramify upon the
outer part of the haunch.

The inferior fasciculi, remarkable for their large size,
are of much more importance to us. The first nerve
largely contributes to the origin of the sciatic ; but it
also sends a considerable branch to the gluteal nerve.
It communicates with the sympathetic and second
lumbar nerve. The second nerve communicates with the
third and sympathetic, and then sends off two large
branches. One joins the sciatic ; the other continues
backward and disappears among the coccygeal muscles.
The third nerve has similar connections, and also joins
the sciatic ; but the major part runs backward, along
the side of the pelvis, and penetrates the muscles of
the haunch. The fourth nerve, being similarly con-
nected, is principally destined to the supply of the
bladder and rectum, and muscles of the anal region.
The fifth nerve runs backward and plunges into the
heads of the coccygeal muscles.

Coccygeal Nerves.
Generally speaking, we find four pairs of them.

288 Coccygeal Nerves.

Like the sacral, they issue from the spine by two sets of
foramina, and are therefore best considered as divided
into superior and inferior sets. The sympathetic not
extending thus far, they have no connection with it.
In other respects they do not importantly differ from
the other spinal nerves.

The superior fasciculi pass out obliquely backward,
communicate with the last of the sacral and with one
another, distribute many muscular branches, and end in
subcutaneous filaments. From the two or three last
originates a considerable nervous cord, which penetrates
the erector coccygis, and may be traced among its fibres
to the extremity of the tail.

The inferior fasciculi likewise communicate with one
another. The first nerve receives a branch from the
last sacral, and detaches one to the perineum. Poste-
riorly, they'all end in one common nervous cord, some-
what larger than that above, which runs between the
depressor and curvator coccygis, branching out in its
course, and ends in filamentous ramifications at the
point of the dock.

V

LECTURE LXVIII.

Nerves of the Fore Extremity.

With the exception of some cutaneous filaments ra-
mifying over the point of the shoulder and extending
thence to the arm, the fore extremity receives all its
nerves, which are comparatively large and numerous,
not to add complicated, from the axillary, better named
the humeral plexus ; and this plexus is constituted, in a
manner that has already been shown, by a small branch
from the fifth, by the principal portions of the sixth and
seventh cervical nerves, and by the main division of the
first dorsal nerve. The plexus, thus formed, resolves
itself into several large nervous trunks, generally about
seven or eight, which surround the axillary artery,
whose particular course and destination I shall now pro-
ceed to demonstrate.

The external thoracic nerves, commonly six
or seven in number, arise from the humeral plexus, and
are dispersed upon the breast and side. Three or four
of them run obliquely downward to give branches to the
pectoral muscles. The others take a backward course,
and send branches to the serratus and latissimus dorsi.
One branch is found turning round the posterior border
of the triceps, whence it becomes superficial and rami-

PART III. U

290 'Nerves of the Fore Extremity.

fies among the fibres of the panniculus/ running thence
into the skin.

The scapular nerves may be distinguished into
the anterior, the posterior, and the subscapular nerves.

The anterior scapular nei've is reflected upward and
forward, in company with the artery of that name,
winds round the anterior costa of the scapula, between
the subscapularis and antea-spinatus, to which muscles
it sends off branches in crossing the dorsum scapulae,
and stretches its ultimate filaments into the triceps.

The posterior scapular nerve, after detaching a branch
to the subscapularis, dips between that muscle and the
triceps. There the trunk splits into several branches
which run into the triceps, teres minor, and shoulder-
joint : one of them is continued upon the outside, round
the cervix humeri, where it becomes subcutaneous,
and ends in the insertion of the levator humeri.

The subscapular nerves, two, three, or four in num-
ber, run upward from the plexus between the scapula
and the chest, and enter the substance of the subsca-
pularis.

The spiral nerve, the largest of the nervous
trunks furnished by the axillary plexus, arises behind
the humeral artery, and runs with the vessel for a short
distance. It then leaves the artery and turns round
the back of the os humeri, between the bone and the
large head of the triceps, and is to be found, covered
by that muscle, coursing the outward surface of the
body of the same bone. Next it plunges deep among
the heads of the extensor^ ; then, much diminished in
size, it insiduously creeps round the neck of the radius,
and penetrates the head of the flexor metacarpi exter-
nus, among the fibres of which its remaining ramifica-

Nerves of the Fun E.vtremity. iyl

tions are expended. Its branches are — 1. Near its
origin, three or four long branches are sent down to the
triceps. 2. Lower down, a branch is separated which
pierces that muscle and gains the front of the elbow
joint, where it escapes through the faschia and takes its
course under the skin covering the arm, and ramifies
upon the fore and outward part of the knee : this nerve
may be distinguished as the external cutaneous nerve.

3. Several considerable branches which penetrate the
heads of the extensor muscles.

The radial nerve clings to the humeral artery,
with which it descends to the inward side of the elbow-
joint, and runs down behind the vessel, along the back
of the radius, to the knee ; there it passes under the
posterior annular ligament, and then continues its course
with the artery, and, as soon as it has descended upon
the leg, takes the name of the internal metacarpal
nerve. Its branches are — 1. Which comes off the
trunk a little below its origin, from its size and impor-
tance is distinguished as the musculo-cutaneous nerve.
After accompanying the trunk for a short way, it leaves
the parent nerve and crosses obliquely behind the flexor
brachii, passing between that muscle and the coraco-
humeralis, to both of which it sends filaments ; it then
winds forward and re-appears upon the upper and fore
part of the arm, where it becomes subcutaneous, rami-
fies upon the faschia, and prolongs its ramifications over
the knee upon the metacarpus. 2. A small slip de-
tached opposite to the elbow-joint which is distributed
to the heads of the flexor muscles. 3. In its course
down the arm, several small twigs to the flexor muscles.

4. Above the knee, a communicating slip separates,
which obliquely crosses over the fleshy terminations

292 Nerves of the Fore Extremity.

of the flexors and joins the ulnar nerve as it passes the
joint.

The ulnar nerve which, at its origin from the
plexus, holds a middle situation between the radial and
the nerve before described — the spiral, also accom-
panies for a short distance the humeral artery. In its
course to the elbow it preserves the line of the os hu-
meri ; there it runs over the inward and back part of the
joint, glides down the arm concealed by the posterior
borders of the flexores metacarpi, inclines a little in-
ward before the tendon of the flexor medius to reach the
back of the knee, where it is found under the posterior
annular ligament, within a dense faschial sheath, creep-
ing along close to the inner edge of the trapezium. From
this, it gains the border of the tendo perforans, and be-
comes the external metacarpal nerve. Its branches are
— 1. Soon after its origin, one that may be called the
internal cutaneous nerve, which runs over the elbow-
joint and ramifies in the loose cellular substance about
the inward part of the olecranon. 2. Three or four con-
siderable branches which penetrate the heads of the
flexors, are detached also to the joint. 3. A little
above the knee comes off" a branch which pierces the
faschia and becomes subcutaneous. After having de-
tached some twigs to the back part of the knee,
this nerve runs along the outer and back part of
the cannon to the fetlock, where it disperses its ra-
mifications. 4. A short but considerable branch to the
back of the knee, which sends twigs into the joint.
5. A branch is sent off" immediately below the knee,
which turns suddenly forward and disperses its ramifica-
tions in front of the leg.

The metacarpal nerves, internal and external,

Nei-ves of the Hind Extremity. 293

continue down the leg along the borders of the flexor
tendons, over the fetlock-joint, where they become the
plantar nerves ; these pursue their course, behind their
corresponding blood-vessels, to the posterior part of the
foot, which they penetrate to the inner sides of the
lateral cartilages. About midway between the knee
and fetlock, the internal nerve sends a branch ob-
liquely over the flexor tendons which joins the external
nerve : with this exception, their branches and ultimate
destination are the same on either side. Their branches
are — 1. Filaments dispersed upon the flexor tendons.
2. A large and important branch that comes off just
above the fetlock-joint, and runs obliquely forward, and
distributes its ramifications to the outward and fore
part of the pasterns, and then ramifies upon the coronet.

The plantar nerve detaches — 1. A branch opposite to
the fetlock-joint that runs, before the trunk, directly to
the lateral cartilage, over which its divisions are dis-
persed. 2. A large branch from the posterior part of the
trunk, just before it dips behind the cartilage, which
passes backward, and sends its filaments into the fatty
frog. 3. Behind the cartilage comes off a branch
which winds forward through a foramen in the ala of
the coffin bone, to go to supply the laminae. The trunk
then enters the foramen in the posterior concavity of the
coffin bone, in company with the plantar artery, and
there divides, and distributes its ultimate branches
through the foramina around its edge to the sole.

Nerves of the Hind Extremity.

We have now to examine the course and distribu-
tion of some large nerves which owe their formation
to the concurrence and union of several of the lumbar
and sacral nerves, in a way that has already been

294 Ne?-ves of the Hind Eitremity.

pointed out ; nevertheless, in commencin<>: my descrip-
tions of them, I shall again briefly revert to the manner
in which they are constituted.

The CKURAL NERVE is derived partly from the
second, but principally from the third, fourth, and
fifth lumbar nerves. It is concealed at its origin by
the psose muscles ; shortly afterwards however it makes
its appearance under the last transverse process of the
loins, which it crosses obliquely, and proceeds directly
backward, in a line with the external iliac artery, to
the outward side of, and rather higher than, the vessel,
but not in contact with it. In crossing; the tendinous
and fleshy insertions of the psoas magnus and iliacus,
it splits into several parts, and these plunge into the
thigh between the rectus and vastus internus, distri-
buting their branches laterally to them and to the
vastus externus behind them. Its branches are —

1. Which comes off* at its root and runs still more
obliquely outward than the trunk, and distributes its
filaments to the iliacus, psoas raagnus, and pectineus.

2. The most considerable and important branch takes
its course along with the trunk, between it and the
artery ; but, instead of leaving the vessel, continues
to accompany it for a short distance below the pubes ;
it then emerges forward upon the faschia lata, and
divides into two cutaneous filaments : of which, one
runs into the stifle and ends in ramifications upon the
fore part of the thigh ; the other is continued down,
in company with the vena saphena, distributing twigs
to the skin covering the inward and anterior part of
the thigh and leg, where it often sphts into two
branches, and is traceable with the vein as low as
the fetlock.

The obturator nerve, contributed to by the

Nerves of the Hind Extremity. 295

third, but principally formed by the fourth lumbar
nerve, sweeps round the brim of the pelvis, first
above, and then to the inner side of, the external
iliac artery, and passes through the anterior nook
of the foramen magnum ischii, detaching some twigs
to the obturator muscles in its passage, and is then
found sunk in the haunch, behind the pectineus, but
before the short and long heads of the triceps, to
which muscles it gives branches, and afterwards creeps
under the gracilis, upon the inner surface of which it
branches out and expends its ultimate filaments.

The gluteal nerve receives a tributory ramus
from the last lumbar, but owes its formation princi-
pally to the first sacral nerve. It leaves the cavity
of the pelvis through the foramen in the anterior part
of the sacro-sciatic ligament, and winds round upon
the dorsum ilii, in company with the gluteal artery,
and is entirely expended in the substance of the
gluteus maximus.

The sciatic nerve, the largest in the body,
having derived its origin from the last of the lumbar
and three anterior of the sacral nerves, immediately
after its formation quits the cavity of the pelvis
through a hole in the anterior part of the sacro-sciatic
ligament, proceeds backward in contact with that
ligament, passes between the hip-joint and the tu-
berosity of the ischium, and plunges deep into the
substance of the haunch. Here we find it split into
three large branches — the popliteal nerves, which are
lodged in an inter-muscular hollow, bedded in adi-
pose membrane, having the semitendinosus and semi-
membranosus posteriorly, the biceps to the outward

296 ISlervea of the Hind Extremity.

side, and the large head of the triceps to the inward
side : in passing through the foramen it detaches three
or four branches to the head of the biceps, about the
same number to the semitendinosus, and two or three
to the semimembranosus. Of the three large nerves
into which the trunk divides — The first and principal one
takes an oblique course between the bellies of the gas-
trocnemii, leaves those muscles where they become
tendinous, and runs to the hock between their tendons
and the muscles of the deep posterior crural region,
clinging to the faschia which envelopes the latter.
At the hock it separates into two nerves — the internal
and external metatarsal nerves : the former runs over the
tendon of the flexor pedis, and upon the leg creeps
along the inward and anterior border of the flexor
tendons ; the latter passes between the tendon and the
base of the os calcis, and pursues a like course upon
the outer side. Their subsequent course and ulti-
mate distribution are the same as those of the plantar
nerves of the fore extremity. Its branches are — 1. A
long branch which at first runs with the popliteal
trunks, then passes between the gastrocnemius ex-
ternus and lower end of the semimembranosus, and
makes its appearance upon the faschia covering the out-
erside of the thigh, where it sends off many cutaneous
filaments, and ramifies over the outer part of the
hock. 2. A long slender branch to the gastrocne-
mius internus. 3. Several filaments to the skin and
faschia, above and about the hock.

The second popliteal nerve passes also between the
bellies of the gastrocnemii, above the first, detaching
twigs to them in its passage, and then spreads into

Sympathetic Nerve. 297

many branches which penetrate the heads of the flexor
muscles of the foot, and send filaments into the stifle-
joint.

The third popliteal nerve, leaving the others, winds
round to the outer part of the thigh, between the gas-
trocnemius externus and the semimembranosus ; there
it crosses the head of the peroneus, and then suddenly
turns down, running between that muscle and the exten-
sor pedis, along with the anterior tibial artery, and takes
its course with it to the middle of the cannon, whence,
instead of accompanying that vessel between the me-
tatarsal bones, it pursues its way along the side of the
large metatarsal bone, over the fetlock-joint, and ter-
minates subcutaneously upon the side of the pastern.
Its branches are — 1. A small one to the semimembra-
nosus. 2. A filament, or two, to the gastrocnemius
externus. 3. A large branch that runs along the
peroneus, under the faschia, and ends superficially in
front of the hock. 4. Branches to the flexor meta-
tarsi and extensor pedis. 5. Various small subcuta-
neous filaments in the remainder of its course.

Sympathetic Nerve.

This nerve, designated sy/wpa^Ae^zc from the univer-
sal influence which it has in the nervous system, is one
no less remarkable for its vast nnd vital importance in
the animal economy than it is for its extensive dis-
tribution all over the body, from the head to the tail,
for its ganglia, for its plexuses, the number and com-
plication of its branches, and its frequent intercourse
and connexion with other nerves belonging to the
head, neck, chest, abdomen, and pelvis. Indeed,
late experimental researches lead us to consider it as
a nervous system of itself, or at least one that renders

298 Sijmpalhetic Nerve.

the parts to which it furnishes nerves, independent
organs, less under the influence of the sensorium, and
altogether free from the controul of the will. The
sympathetic nerve may be said to take its beginning
from an oblong reddish body, which is found at the
base of the cranium, beneath and in front of the
atlas, denominated the anterior cervical ganglion. I
would observe here however, that the several nerves
connected with the ganglia, (however I may treat of
them in my descriptions) may be considered either as
emanating from the substance of the ganglion, or as
contributing to its formation.

The anterioj' cervical ganglion may be said to be formed
principally by two branches which are sent down from
the fifth pair, the larger of which accompanies the in-
ternal carotid ; by two or more fine filaments which
are traceable to the edges of the petrous portion of
the temporal bone, and are probably derived from
the sixth pair; and by two or three other nervous
threads accompanying the eighth pair, which seem
to spring from the medulla oblongata *. These branches
then, we will say, it receives. It transmits filaments

* I am by no means satisfied however about the origin of these
threads of nerves, which are so fine that I have not hitherto been
able to follow them distinctly through the dura mater, whose fibres
so much resemble the nerves themselves. Of the two branches
said to come from the fifth pair, Girard traces the larger one
to a ganglion under the occiput, opposite to the origin of the
Eustachian tube, which he calls the sub-occipital ganglion; the
other, he says, joins a little ganglion in the cavernous sinus.
From the sub-occipital ganglion, he traces two or three filaments
onward to the fifth pair, at their origin ; and one or two, much
larger, he finds, which seem, he says, to be destined to the me-
dulla oblongata. Vide Girard's Anal. Gen. Edit. II. Tom. II.
page 129.

Sj/inpathetic iSerVe. 290

of communication to the par vagum and its laryngeal
branch, to the glosso-pharyngeus, the accessory, and
the inferior branches of the sub-occipital and first cervi-
cal nerves. Posteriorly, it sends off a filament which
crosses to the carotid artery, where it divides and
anastomoses with the carotid branches of the par
vagum. At its posterior extremity the ganglion grows
smaller and ends in the sympathetic nerve, which,
at first, has the appearance of being a continuation
of it. At its origin, this nerve is deeply lodged be-
tween the carotid artery and par vagum ; it takes
its course along the neck likewise between them ;
indeed, it is so closely united with the latter that,
being invested in the same cellular sheath, at first
view they appear but as one nerve : they are readily
' distinguished, however, in being disunited, by the
comparative small size of the sympathetic. At the
bottom of the neck, this nerve lies within the angle
formed between the carotid and vertebral arteries;
it then runs outward above the vertebral artery, over
which we find a bulbous enlargement of it, which
takes the name of the posterior cervical ganglion.
The only branches given off by the cervical trunk of
the sympathetic, are several threads of communication
which it has with the par vagum, as they proceed
backward together.

The posterior cervical ganglion, smaller than the an-
terior, is formed under the first dorsal vertebra. Froni
it pass — 1. A large branch, and sometimes a smaller
one with it, to the sixth cervical nerve, by which
it has a mediate communication with the five ante-
rior cervical nerves. 2. A branch to the seventh
cervical nerve. 3. A filament to the first dorsal nerve.

300 Sympathetic Nerve.

4. Another to the second dorsal nerve. 5. Branches
to the tracheal plexus. 6. Filaments to the recurrent
nerve. 7. To the cardiac plexus.

The tracheal plexus is an assemblage and in-
tercommunication of nerves, furnished by the par
vagum and recurrent as v^^ell as the sympathetic, which
ramify over the under surface of the trachea as it
passes between the two first ribs, from which filaments
are transmitted to the cardiac plexus. It supplies this
part of the air-tube, and also the contiguous portion
of the esophagus.

The cardiac plexus, constituted of larger
branches from the same nervous trunks, and also of
filaments from the tracheal plexus, which are readily
traceable to the roots of the large bloodvessels, is
formed for the supply of the heart.

From the posterior cervical ganglion, the sympa-
thetic continues its passage backward, under the
articulations of the ribs with the spine, to the dia-
phragm, which it pierces in company with the posterior
aorta. Between the heads of the ribs it presents lit-
tle knots — dorsal ganglia, which correspond in number
to the intercostal spaces. These ganglia are of very
small size when compared with the cervical, and give
off, each of them, two filaments to every intercostal
nerve. — As the sympathetic nerve pursues its route
along the spine, it grows flat, spreads out its fibres,
and at length separates into two branches, one of
which, by means of frequent reinforcements from the
ganglia as it passes by them, ultimately attains a
larger size than the original parent nerve : this,
from being destined to supply the abdominal viscera,
is named the greater Splanchnic nerve. Before it

Si/mpathetic Nerve. 301

leaves the chest, while running along the crus of the
diaphragm, the sympathetic detaches another branch,
which turns backward upon the crus in the form of an
arch in escaping from the cavity, denominated the
lesser, secondary, or accessory splanchnic nerve, whose
destination is nearly similar to that of the former.

These three nerves, the two splanchnics and the
sympathetic, make their entry into the abdomen along
the under side of the crus of the diaphragm : the
splanchnics are then thus distributed. The greater
splanchnic turns downward, and contributes its branches
to the formation of the semilunar ganglion ; the lesser
splanchnic likewise sends most of its branches to that
ganglion, but it also transmits two or three long fila-
ments backward to the renal plexus : and both the
splanchnics detach communicating filaments to the
sympathetic.

The semilunar ganglion, then, is constituted of branches
from the left division of the par vagum, and of almost
all those of the splanchnic divisions of the sympathetic.
This ganglion partakes of the semilunar figure, lies
close under the posterior aorta, at the root of the
coeliac artery, and occupies the space between that ves-
sel and the anterior mesenteric artery. It consists of
a number of small ganglia, connected one to another,
and is surrounded by a plexus of nervous filaments ;
which little ganglia have been denominated the cccliac.
From the irregular convex border of the semilunar
ganglion, nervous filaments shoot in various directions,
which, from having been compared to the rays of the
sun, have been denominated altogether the solar plexus ;
from which divergent filaments, the several minor plex-
uses of the abdomen may be said to derive their for-

2

302 Sifmpathetic Nerve.

I mation, taking names according to the viscera they are

particularly designed to furnish with nerves. The first
I shall notice is

The splenic plexus, which is a network of small nerves
surrounding the splenic artery. It sends some fila-
ments to the pancreas, but the majority of its detach-
ments run to the spleen.

The hepatic plexus consists of a similar nervous inter-
lacement around the hepatic artery : it is very exten-
sive ; for it winds round the vessel from its origin to its
teiinination in the porta of the liver. It transmits fila-
ments— 1. Along the phrenic arteries to the diaphragm.
2. To the stomach. 3. To the pancreas. 4. It then
divides into right and left hepatic plexuses, which cling
to the arteries of the same names, and accompany
them in their ramifications through the liver.

The anterior mesenteric plexus is a vast assemblage of
nervous filaments, intricately wound round the trunks
of the anterior mesenteric arteries, which furnish nu-
merous filaments that proceed along with these vessels,
greatly exceeding them in number, to ramify within
the substance of the small intestines, the coecum, and
coecal portion of the colon.

TJie aortic plexus^ a name given to the frequent inter-
communication of some fine filaments which are sent
backward along the posterior aorta from the solar
plexus, with two or three contributory branches from
the trunk of the sympathetic. Most of the filaments
derived from it, pass on to form

The posterior mesenteric plexus, one that is likewise
re-inforced by branches, which are comparatively large
in size, from the sympathetic. It transmits nerves to
that part of the colon left unsupplied by the anterior

Si/rnpathetk Nerve. 303

mesenteric plexus, and to the rectum : some few of
them also ramify in the substance of the mesocolon,
and others run into the lymphatic glands seated within
the folds of that membrane.

The hypogastric plexus, removed still further backward
than the posterior mesenteric plexus, consists of divers
delicate nervous filaments ramifying upon the aorta,
and spreading themselves, entangled in cellular sub-
stance, about its bifurcation. This plexus is also mul-
tiplied by branches coming from the sympathetic. The
filaments which depart from it run to the pelvic viscera
and the organs of generation.

The renal plexus is a more important one ; it is pro-
duced by the intercommunication of a few filaments from
the lesser splanchnic nerve with numerous others from
the solar plexus. It is found close to the aorta, immedi-
ately behind the anterior mesenteric plexus. It conceals
the origins of the emulgent arteries, spreads round them
in their passage, and sends filaments in company with
their branches into the substance of the kidneys. It
also furnishes with nerves, the capsulae renales, the
renal glands, and the beginnings of the ureters.

The sympathetic nerve in the abdomen travels over tlie
sides of the bodies of the lumbar vertebrae, below the
articulations of the ribs, covered by the crura of the
diaphragm, and thus pursues its course into the pelvis.
Here likewise it forms ganglia, which correspond in
number to that of the lumbar nerves ; and from eveiy
ganglion come off two filaments : one of which runs to
the correspondent lumbar nerve the other crosses the
aorta, and, by joining the aortic plexus, communicates
with nerves coming from the sympathetic of the other
side.

304 Sympathetic Ne9've.

From the loins, the sympathetic descends into the
pelvis, where it takes its course laterally along the body
of the sacrum. Five sacral ganglia, corresponding to
the five sacral nerves, w^ith which they communicate,
are found here, and between them run in arches across
the sacrum several intercommunicating filaments. In
quitting this bone, the nerve grows so small, and is so
firmly adherent to the ligamentous covering of the os
coccygis, that I have not yet succeeded, to my mind,
in ascertaining the precise manner in which it finishes
its course : it is said, however, to do so by forming a
union with its fellow.

\* I take this opportunity of acknowledging the services af-
forded me in the dissection of the nerves by Mr. Bean, V. S., who,
I believe, is now in practice at Durham. Unwearied assiduity and
unusual zeal had qualified him in an especial manner for such an
undertaking; and I hope that he is now enjoying that support
■which his professional acquirements will always render him de-
serving of.

LECTURE LXIX.

Distribution of Arteries.

It has been observed, in former lectures, that the
more perfect animals are formed with two distinct and
complete arterial and corresponding venous systems ;
and that these vascular systems, though both transmit
the same blood, have no intercommunication but through
the medium of the heart, which, in fact, is a double
organ ; and that one system is solely employed in the
pulmonary circulation, but that the other pervades
every other internal organ and extends to the remotest
parts of the body : the pulmonari/ system was described
with the lungs ; it is now my intention to trace the ra-
mifications of the

Aortic System.

These may be compared, as a whole, to a short but
straggling and very branchy shrub or tree of luxuriant
but extremely irregular growth ; and their number and
distribution may be presented in idea to the mind by
recalling to memory, that no organized part, the lungs
even not altogether excepted, is without few or many
of them. To follow the course or give distinct names

PART 111. X

306 Aortic System.

to the very small branches, would answer no useful prac-
tical end, while it would heavily encumber our minds
to carry such a vocabulary about with us ; and though
we succeed in a general way in discovering their desti-
nations, to say precisely in what structure or arrange-
ment they ultimately end in too many instances yet
needs further demonstration : I shall therefore not dwell
on these points of description, (many of which have
already been discussed) but direct my observations to
those vessels in particular whose size, situation, or
connection, may render a knowledge of them important
in operations, cases of hemorrhage, or physiological
and pathological researches.

'The AORTA, the main trunk of the large arterial sys-
tem, rises out of the base of the left ventricle in a ver-
tical direction in the space between the left auricle and
the pulmonary artery, which vessel, by inclining forward
as the aorta leans backward, leaves visible on a side view
a small angular portion of the latter. The length of the
trunk is about two inches ; and the ascent takes place
opposite to the body of the fourth dorsal vertebra, be-
low which it bifurcates into two curved vessels of un-
equal dimensions, the aorta anterior and the aorta pos-
terior.

The only branches furnished by the main trunk are
the coronary arteries, which arise near its root, just
over two of the semilunar valves. The right coronary ar-
tery emerges from between the pulmonary artery and the
right auricle, winds round the fissure separating that
cavity from the right ventricle, and turns down under
the termination of the vena cava, withinthe furrow di-
viding the ventricles, upon the side of the heart, dis-
tributing lateral ramifications in its course which pene-

Anterior Aorta.

307

trate the substance of the parietes, and ending in small
spiral branches near the apex cordis. The left coronary
artery in passing out between the pulmonary artery and
left auricle, sends off a large branch which encircles
the other auriculo-ventricular fissure ; it then takes its
course downward within the ventricular furrow upon
the left surface of the heart, distributing lateral
branches which supply the parietes forming this side,
and ending in spiral ramifications which extend quite
around the apex cordis, and anastomose with those
upon the opposite side-

Anterior Aorta.

The anterior, smaller, and shorter division of the main
trunk, whose length falls somewhat short of an inch,
in ascending, bends forward, and divides below the
body of the third dorsal vertebra into the right and left
arteriae innominatae vel communes. The course of this
vessel is under the windpipe and rather to the left of
it, within the space of the mediastinum. The trunk
itself furnishes no branches ; but its bifurcations give
origin to those large arteries which are distributed
over the breast, neck, head, brain, and anterior extre-
mities.

Arteria Innominate^ vel Communes.

The right artery is considerably longer than the left,
and measures nearly as much again in circumference in
consequence of its forming the common carotid artery
or the trunk from which the two carotids spring, after
it has detached branches to the right side correspondent
in size, number, and distribution to those into which
the left division resolves itself. These vessels form a

X 2

308 ArtericE Innominate vel Communes.

very acute angle as they leave the anterior aorta, and
pursue their course horizontally forward, diverging very
gradually as they advance : the right is placed lower
than the left, and lies more immediately under the
windpipe, having the vena cava anterior upon the
other side of it ; the left describes a curve upward in
passing forward, inclines outward and gets under the
esophagus : both branch out about the middle of the
space between the two first ribs, where the right ends
in the two carotid arteries, the left in the vessels I shall
now describe, which, as was observed before, are
nearly the same on one side as on the other.

1. The dorsal artery generally comes off in
one common root with the next vessel. From its origin,
it curves upward and backward to perforate the second
intercostal space, which it does very obliquely close to
the posterior edge of the first rib, a little below its
head; out of the chest it pursues the same oblique
course, crossing over the transverse process of the
second dorsal vertebra, and then ascending upon the
spines of the withers, among the muscles attached to
which its ramifications are expended. Its branches
worthy of names are — a. Superior Mediastinal, a twig
detached near its origin to the mediastinum, h. An-
terior intercostal, a branch sometimes nearly equal in
size to the dorsal itself, given off just before the vessel
penetrates the intercostal muscle, by which the second,
third, fourth, and fifth intercostal arteries are furnished :
the reason for this is, that the posterior aorta, from
which all the posterior intercostals spring, is too far re-
moved from these ribs to send vessels to them ; their
deficiency therefore was conveniently supplied by the
anterior intercostal. The intercostal branches follow

Arteria Innominattv vel Communes. 309

the posterior margins of their correspondent ribs, each
running within a shallow groove ; midway however
between the vertebrae and sternum they leave the ribs for
the middle of the intercostal spaces, and end in several
slender ramifications, some of which may be traced as
low as the sternum, there anastomosing with similar
ones coming from the internal pectoral artery. The
intercostals in their course detach twigs to the pleura,
but more especially supply the intercostal muscles.

2. The postkrior cervical artery, arising
in common with the dorsal on the right side, but by a
separate root on the left, takes an opposite direction
to that vessel, inclining forward and upward. It tra-
verses the upper part of the first intercostal space,
piercing the muscle filling it with considerable obliquity,
and then ascends in a winding course between the
transverse processes of the first dorsal and last cervical
vertebrae, upon the body of the latter, where it turns
forward, and runs as high as the vertebra dentata, close
to the roots of the ligamentum nuchae, covered by the
complexus major to which its ramifications are princi-
pally distributed. Besides some small and unimportant
branches within the chest, it gives off the first intercos-
tal artery, which descends behind the first rib and anas-
tomoses with twigs from the internal pectoral.

3. The vertebral artery is a vessel of consi-
derable size, and is important from being one of the
principal conduits of blood to the brain. It arises with
a sort of bend from the upper part of the arteria inno-
minata, immediately opposite to the first rib, so that if
a knife were thrust into the chest behind the rib the ar-
tery would just escape puncture. The right is at xia
origin placed lower than the left, and deviates some-

310 Arteries Innominate vel Co7nmunes.

what less from a straight line in proceeding close under
the transverse process of the seventh cervical vertebra
to enter the foramen through that of the sixth. They
then continue their passage to the head, passing di-
rectly through the foramina of the fourth, third, and
second vertebrae, wherein they run securely barred from
external injury, and, arriving at the atlas, make a curve
upward upon its transverse processes, proceed through
the posterior pair of foramina, and enter the foramen
magnum. In its course along the neck, the vertebral
artery detaches several short branches of considerable
size which turn round the transverse processes and
ramify among the deep-seated muscles. It also
sends some smaller ones inward, which enter the inter-
vertebral holes for the supply of the medulla spina-
lis and its membranes. Under the atlas, the vertebral
trunk receives a large vessel of communication from the
internal carotid : but I shall suspend its further descrip-
tion until we come to investigate the vessels of the
brain.

4. The internal pectoral artery, less in
volume than the vertebral, leaves the trunk below, op-
posite to the origin of that vessel above, protected by
the first rib, along the posterior and inner margin of
which it descends in a perpendicular direction towards
the sternum. Leaving the lower extremity of the rib,
it makes a broad sweep downward and backward, and
descends upon the internal surface of the second bone
of the sternum ; it afterwards diverges gradually from
its fellow, traverses the ends of the cartilages of the pos-
terior true ribs, and, having crossed that of the last,
splits into two divisions. One of these ascends upon
the internal part of the chest along the border of the

Arteria: Innominatcc vel Communes. 311

seventh true cartilage, thence it crosses the false carti-
lages, detaching slender ramifications to them which
anastomose with some of the posterior intercostals, and
makes its way towards the flank, and disperses its ulti-
mate branches among the muscles there, some of which
reach far enough to communicate with the ramifications
of the circumflex artery of the ileum. The other divi-
sion, generally considered as the continuation of the
trunk, being rather the larger one, pierces the sheath
and makes its appearance upon the upper surface of
the rectus, over which it ramifies extensively, sending
branches out that anastomose with the epigastric.
Exclusively of these divisions, the trunk detaches mus-
cular branches along the first rib, inwardly anterior
mediastinal vessels, larger branches to the muscles of the
sternum, and inferior mediastinal, and also thymic twigs.

5. The exteknal pectoral artery, compara-
tively small and unimportant, comes off" from the under
part of the trunk, makes a turn downward in front of
the sternum, and distributes its ramifications among the
pectoral muscles : this artery is in some subjects de-
rived from the internal pectoral.

6. The inferior cervical artery, longer and
larger than the afore-described vessel, arising from the
common trunk opposite to or in company with it,
makes its exit from the chest below the vertebral ar-
tery, and then bends outward. At the bottom of the
neck it divides into several branches : these run prin-
cipally to the contiguous muscles, though some few
ramify within the adipose substance in the neighbour-
hood, and others are destined to the absorbent glands
hereabouts.

7. The seventh and last branch, and largest if we

312 Axillary Artery.

except the carotids on the right side and the continua-
tion of the main trunk on the left, is the

Axillary Artery,

The source from which spring all the arteries
OP THE FORE EXTREMITY. This vessel IS SO situatcd
between the scapula and the trunk that not only is it
out of the way of all injury, but it cannot be got at for
the purpose of demonstration without detaching the
limb from the side. It arises within the chest from
the arteria innominata, gains exit by making a sudden
turn around the first rib, rather below its middle, cross-
ing the lower border of the scalenus in the turn ; it is
first directed outward in this flexure and then back-
ward, and at length reaches the inner part of the head
of the humerus where it makes another turn backward,
and afterwards takes the name of brachial artery. Its
branches are — 1. The external thoracic extends back-
ward across the arches of the ribs, taking the same
course as the vessel called the " spur vein/' and supply-
ing the muscles thereabouts. 2. The humeral thoracic
runs to the point of the shoulder and gives its branches
to the levator humeri and shoulder-joint. 3. The dorsa-
lis scapula ascends in a flexuous manner obliquely upon
the shoulder-joint, crossing the insertion of the sub-
scapularis ; it then runs for a short way along the
anterior costa, around which it afterwards continues to
reach the antea-spinatus. 4. The subscapularis, a large ar-
tery which also arises from the upper part of the trunk,
but near to its termination. It creeps upward along
the posterior costa, screened from view by the edges of
the subscapularis and teres major, to both of which
muscles it detaches laterally several small branches.

Axillary Artery. 313

and ends near the posterior angle of the bone. It gives
otr a considerable branch at a short distance from its
origin which proceeds in a waving line across the inner
surface of the triceps, and ends in the panniculus
carnosus ; and another, a deep-seated one, about the
middle of the costa, which is principally expended in
the head of the triceps.

The humeral artery descends from the inner
and back part of the head of the os humeri in an
oblique direction to the inferior and anterior part of the
body of the bone, where it divides into the ulnar,
spiral, and radial arteries ; on its inner side, it has the
spiral and ulnar nerves ; in front, the radial nerve ; and
behind, the humeral veins : and it is covered internally
by the pectoralis magnus, to which it sends some small
branches. But its principal branches are — 1. One
near its origin which crosses the bone to get to the
flexor brachii, and sends twigs to the shoulder-joint.
2. A posterior branch, arising a little lower down, which
bifurcates and enters the triceps. 3. Near its termina-
tion, another anterior branch to the flexor brachii.
Where the artery divides, it is covered by the humeral
plexus of veins, and by the absorbent glands of the
arm.

The ulnar artery consists of a common root
from which spring three or four vessels of considera-
ble size running in waving lines upon the inner side
of the lower end of the humerus. The upper one,
commonly the largest, is directed to the ulnar, splitting
however before it reaches the bone, and sending one
branch upward upon the olecranon, and another down-
ward to the heads of the flexors ; to which muscles the
other branches of this vessel are exclusively distributed.

314 Axillary Artery.

The spiral artery, the outermost division, turns
round the os humeri, passing under tlie flexor brachii
and sending a recurrent branch to it, to arrive at the
front of the head of the radius, where it splits into
several branches of which — 1. Some run into the elbow-
joint. 2. Others larger and more in number penetrate
the heads of the extensors. 3. Two long slender ones
descend upon the radius, under the extensor muscles
to which they give branches in their course, as low as
the front of the knee, and there end in ramifications
about and into the joint, anastomosing with others
coming from the radial.

The radial artery, the principal division of the
humeral, continues its descent along the radius, inclin-
ing as it descends from the inner to the back part of
that bone ; so that if it were designed to cut down upon
it about the middle of the arm, the incision should
correspond to the inner edge of the radius, from which
the faschia must be first detached, and afterwards the
flexor metacarpi internus. The radial nerve, which
here accompanies it, runs first upon its outer side
and subsequently gets behind it. A short way above
the knee, it splits into the metacarpal arteries. It
gives off" — 1. Small vessels to the elbow-joint. 2.
Various branches to the flexor muscles during its
course. 3. The medullary artery of the radius, about
one-fourth of the length of the bone downward.

The small metacarpal artery descends, within
a cellular sheath, along the inner and back part of the
knee, more outwardly situated than the large one, from
which it is separated by the posterior annular liga-
ment. It continues its descent along with the meta-
carpal vein (which runs to its inner side) till it gets

Axillary Artery. 315

below the knee, where it bifurcates and transmits its
divisions down the front of the suspensaiy hgament —
between it and the cannon bone. It sends off — 1. Cu-
taneous branches over the front of the knee, which
anastomose with the spiral. 2. Ramifications to the
front of the cannon. 3. To the suspensary ligament.

The large metacarpal artery, which may be
regarded as the continuation of the radial trunk, con-
tinues it course down the leg by the side of the tendo
perforatus, passing with it at the knee under the pos-
terior annular ligament, inclosed within a cellular
sheath of its own. As it proceeds, it inclines to the
side of the tendo perforans, and in approaching the
fetlock, gets in advance of that tendon ; just above
the joint, where it is situated between the tendo per-
forans and the suspensary ligament, it splits into three
vessels. The middle division gets between the bifur-
cated terminations of the ligament, and between it and
the bone forms a transverse arch, from which three
recurrent arteries retrace in a flexuous line the suspen-
sary ligament, and form communications with the small
metacarpal artery : the lateral divisions become the
plantar arteries. From the arch below come off two
lateral branches which descend into the joint.

The plantar a^tizui^^, external dirvdi internal, in
the fore extremity result from the bifurcation of the
metacarpal, in the hind from that of the metatarsal
artery : I prefer this appellation for them because it
denotes their destination at once, and because it saves
us the useless division of a trunk only six inches in
length into three arteries, and because our descriptions
and memories are not clogged by it as they are by the
"large pastern," and the "small pastern," and the

316 Axillary Artery.

" coffin arteries." Their general distribution is the same
both in the fore and hind feet.

These arteries, in emerging from their origin behind
the flexor tendons, form the two sides of a triangle, the
base of which, turned downward, is represented by a
line drawn across the backs of the sesamoid bones, the
apex being the point of bifurcation. They descend the
fetlock upon the sides of the sesamoids, in company
with their viens which run in front of them, and with
the plantar nerves which proceed behind them ; in this
part of their course they describe corresponding curves
outward to conform to the prominence of the fetlock,
and henceforward pursue the same uniformity in course
and distribution, so that we need only for the future
make mention of one. In its passage over the sesa-
moid, the outer edge of that bone rose between it and
the flexor tendon, but in quitting the fetlock, the ar-
tery again approaches the tendo perforatus and runs
beside it to its termination in the head of the os co-
ronae, at which place the artery sinks behind the carti-
lage into the substance of what is called the " fatty
frog." Inclining forward in its subsequent descent,
the artery next passes the inner and upper extremity of
the ala of the os pedis, where it enters a groove scooped
in that bone which conducts it, obliquely forward and
inward, to the foramen in the posterior concavity of
the bone. Here we lose sight of it altogether — the
knife and forceps no longer avail us to discover its pro-
gress and destination : either the bone should be chi-
selled away or (the vessels being previously injected)
be eroded by maceration in an acid ; we shall then
detect the artery in the interior of the coffin-bone, mak-
ing a turn outward again, and subsequently another

I

I

I

Axillary Arteri/. 317

inward, in the course of which it meets with its fellow ;
the trunks then coalesce, and in so doinor form an arte-
rial semicircle corresponding to the circumferent line of
the edge of the os pedis, which has been very properly
named by the Professor, the circulus arteriosus* . The
plantar vessels and nerves are invested in their descent
to the foot by cellular substance, which bind them
loosely to the parts contiguous to which they pass ; this
accounts for their canals being flexuous when distended
with injection or when the foot is flexed upon the fet-
lock : a circumstance that seems to have escaped the
notice of writers on the foot. The branches of the
plantar artery are many and important. After detach-
ing some small ramifications inwardly to the fetlock,
posteriorly to the flexor tendons which anastomose with
their fellows, and anteriorly to the extensor tendon
which are also anastomotic, it sends off — ■

1. The perpendicular artery , a little above the mid-
dle of the OS sufFraginis : this slender branch descends
upon the side of the bone, inclining forward, and ends
over the coronary ligament in anastomosis with its fel-
low, forming an arch, presenting its convexity down-
ward, called the superjicial coronary, from which ema-
nate about eighteen small descending arteries that run
directly over the coronary plexus of veins, whose prin-
cipal function it is said is "to secrete the crust." I
would remark here however, that, although I believe
what I give to be the general arrangement of these
arteries, there is so much variation that I cannot
vouch for the correctness of this description, however
I may stand amenable for its accuracy. The trunk

* Professor Coleman, " On the Foot of the Horse." Vol. II.

318 Axillary Artery.

having detached various small unimportant branches
backward, one great design of which appears to have
been to preserve free and continual intercouse with
the opposite trunk, it next sends off, below the pas-
tem-joint. —

2. The transverse artery, which proceeds directly
across the front of the os coronee, underneath the ex-
tensor tendon, to join the corresponding branch from
the other side, the two together forming the superior
coronary circle: this pours most of its blood through
two short lateral conduits, the communicatiiig arteries,
into the inferior coronary artery ; other short twigs are
sent both upward and downward from it. The two

' that have been described may be considered as the
anterior branches of importance ; let us now proceed
to those arising posteriorly: the first we need notice
particularly is —

3. The artery of the frog. It comes off opposite to
the pastern -joint, and descends obliquely inw^ard
through the substance of the fatty frog, wherein it
bifurcates : both divisions take nearly the same di-
rection, one passing down upon the side of the cleft
along which it continues, distributing branches in its
course to the toe of the frog, and forming communi-
cations with the vessels of the sole ; the other ramifies
over the heel of the frog, and sends branches outward
to the cartilages. ,

4. The lateral laminal artery leaves the trunk just as
the latter reaches the os pedis, passes through the fora-
men in the ala, and proceeds within a superficial groove
to the front of the foot, distributing branches upward
and downward to the laminse, and disappearing through
a small foramen in the anterior and lateral part of

Axillary Artery. 319

the coffin, which it enters to fomi a communication
with the circulus arteriosus. From this vessel, a
branch descends upon the side of the bone to join the
circumflex artery.

5. The circulus arteriosus, resulting from the coali-
tion of the main trunks, preserves to a certain extent
around the toe of the coffin the same curve interiorly
that is made by the exterior edge of the bone itself,
at the distance of about an inch above it. From it
arise two principal sets of vessels.

1. The anterior laminal arteries, numerous, small,
short branches springing from the front of the circulus,
and making their exit through the various foramina in
the front and sides of the coffin to ramify among the
laminae, anastomosing with the descending and lateral
coffin arteries.

2. The inferior communicating arteries, " thirteen,
and sometimes fourteen" in number, according to the
Professor, arise from the convexity of the circulus
arteriosus, and descend through the foramina in front of
the coffin, a little above its boundary edge ; having
made their exit, they continue the same direction to
gain this edge around which they are all received by
the—

3. Circumjiex artery, which is commonly described
as encircling " the toe" of the coffin-bone. Then,
again, from this vessel spring —

The solar arteries, (which may be so named from
their radiated arrangement,) thirteen or fourteen in
number, which, though they run from the same chan-
nel, do not " take their origin immediately opposite
the termination of the vessels into the circulus arte-
riosus." These vessels are destined for the supply

/

I

320 Axillary Artery.

of the sole, upon wliicli they run in radii, at pretty
equal distances, whose common centre is the toe of the
frog, where they end in communications with the ar-
teries of that body.

One great and evident design in the distribution of
arteries, is, so to direct them in their course that they
maybe out of the way of injury and pressure, or else,
so to arrange their communications that the pressure
to which they are on occasions unavoidably subjected
may not altogether arrest the circulation. No part
of the body exhibits a more striking illustration of
the latter than the arterial arrangement we have just
been examining. This object indeed seems to have
been carried further in the foot than elsewhere ; the
ultimatum being rather to furnish an unceasing flow
of blood (and an equable secretion of horn consequent
on it) than to provide against unavoidable or accidental
impediment, a point that has been argued in a very
convincing manner by the Professor in his observa-
tions on the foot. I do not however concur altogether
in opinion with this ingenious physiologist when he
infers, that this arrangement of the arteries "must im-
pede the passage of the blood, and render the circula-
tion slower:" certainly, "on mechanical principles,"
such would be the result ; but we must remember that
the arteries are not passive tubes, indeed there appears
reason to believe, on the contrary, that they them-
selves take a very active part in the circulation, and
if such can be shown to be the case (knowing that
they are constantly filled with blood) their distribu-
tion or arrangement can have, I apprehend, no such
effect : in opening the circumflex artery I have inva-
riably found that the blood flowed from it as fast as

1

Axillary Arterij. 321

from any other vessel of the same diameter in the body.
— Furthermore, the Professor justly remarks, that the
circulus arteriosus is " more complete than is found in
any part either of the horse or the human subject.
If one trunk be totally stopped, the circle below will
not be distended with the same force, but as completely
filled as before." — That " the anterior coffin (circum-
flex) artery must be j)erpetually filled with blood, so
long as one vessel remains entire." — And that the
arteries pass through the substance of the os pedis
** to prevent pressure on them ;" but " if the veins
had returned their blood through it, the bone must
have been made so porous as to have rendered it too
weak to support the weight of the animal."

PART III. t Y

LECTURE LXX

The Carotid Artery.

The ripjht arteria innominata, having detached seven
important branches which vary but little in their mode
of origin, and not at all in their general course and dis-
tribution, from the seven arteries into which the left di-
vision resolves itself, becomes the common carotid, a
large vessel about an inch in length, emerging through
the upper part of the anterior opening of the chest,
having the trachea between it and the spine above, the
vena cava anterior below it, and dividing as it quits
the cavity into the right and left carotids. These ar-
teries bend upward from their origin, diverging as they
mount the neck so as to leave a space between them
for the windpipe ; having climbed the sides of which,
they closely embrace and cling to it for the first part of
their course ; towards the middle of the neck however
we find them gradually inclining, as they ascend, to
its posterior and lateral borders, the line of direction of
which they preserve during the remainder of their
course*. Having reached the top of the larynx, the

* The carotids lie more deeply the higher they proceed up the

The Carotid Arteri/. 323

carotid of either side splits into three divisions : — the
external and internal carotids, and the ramus anastomo-
ticus: here, though the trunk itself becomes deeply
lodged in soft parts, its situation is well indicated by
the larynx, with which it is in contact, below, the
transverse process of the atlas above, the angle of the
jaw a little in advance of it, and the coronoid pro-
cess farther removed above and before it : a deep
incision corresponding to the posterior border of the
stylo-maxillaris, would sever the artery at or very close
to its division. This vessel detaches — 1. Several
unimportant muscular branches in its progress rip the
neck. 2. The thyroideal artery, coming off opposite to
the top ring of the trachea ; a branch of no mean size
which turns round the windpipe and enters the sub-
stance of the thyroid gland. In its way, it furnishes the
laryngeal, a small artery that perforates the ligament
uniting the cricoid and thyroid cartilages, and is dis-
persed upon the membrane lining the larynx : in some
instances this forms a branch of the main trunk. The
common division of the carotid is into the three vessels
just named ; but not infrequently we meet with a fourth
coming from the point of ramification, the additional
one being the facial artery ; and occasionally we only
find a simple bifurcation of the vessel into the external
and internal carotids.

neck : each is covered by the sterno-maxillaris ; and the readiest
way to find the vessel is to make a cut along the upper border of
this muscle, and depress it with the finger or handle of the knife.
The artery is separated, except at the bottom of the neck, from the
jugular vein by a thin partition of muscular fibres ; the par vagum
accompanies it outwardly, and the sympathetic nerve runs between
tlie two.

324

Tite External Carotid Artery

Is the larp^e division, which may justly be regarded as<
the continuation of the trunk of the common carotid
itself. It takes a flexuous course, first curving down-
ward behind the angle of the jaw, where it crosses the
insertion of the stylo-maxillaris, by which it is here
defended from injury ; it next makes a curve upward
and forward, crosses the membranous sac of the fauces,
and passes between the stylo-maxillaris and cornu of
the OS hyoides, deeply buried under the parotid gland ;
it then makes a third curve which directs it forward,
along the posterior border of the branch of the jaw, and
to that it afterwards corresponds until it bifurcates,
which it does immediately behind the neck of the con-
dyle. This artery is so bedded in glandular substance,
surrounded by venous and nervous trunks, and pro-
tected by neighbouring bony prominences and muscles,
that but a small, and that the upper, portion of it is
safely accessible to the knife : rather more than an inch
below and behind the condyle, it is comparatively super-
ficially lodged, being there only covered by the anterior
tiiin border of the parotid and a thick aponeurosis, in
addition to the common integuments. The first branch
of the external carotid is the

1. Submaxillary artery: it comes off behind
the cornu of the os hyoides, just as the carotid is going
to make its second curve, and ranks next in size to the
trunk itself. It takes an oblique course downward and
forward within the sub-maxillary space, preserving at
first the hne of the coniu ; it then crosses the lower
portion of the pterygoideus, and reaches the posterior
border of the branch of the jaw, about one-third of its
length downward, which it turns round to arrive upon

The External Carotid Artery. 325

the face : here it becomes subcutaneous, distinctly
perceptible to the feel, and very conveniently compres-
sible, on which account it is the vessel ordinarily se-
lected to convey a knowledge of the state of the pulse.
In ascending upon the side of the jaw, the artery cor-
responds to the anterior border of the masseter ; it does
not reach however the alveolar processes before it ends,
by a pretty equal division, in the facial and inferior
labial arteries. — Its branches are — a. The ascending
pharyngeal, which mounts obliquely over the cornu of
the OS hyoides, and ramifies upon the side of the pha-
rynx, giving off commonly a laryngeal twig or two in
its way, and another to the velum, which in some in-
stances is derived from the submaxillary itself, b. Va-
rious inconsiderable branches to the pterygoid muscle
and parotid gland, c. The lingual, nearly or quite
equal in magnitude to the submaxillary itself. It first
bends its course obliquely inward, detaching a few
twigs into the submaxillary space ; it then splits into
two arteries, the ranine and the sublingual. The ra-
nine, the larger one, the apparent continuation of the
lingual, turns downward and proceeds in a flexuous
manner along the under part of the tongue, serpen-
tining between the muscles and transmitting many
branches into the interior; it continues of large size
even to the tip of the organ, wherein its extreme ra-
mifications are expended. Its ramifications have no
anastomosis in ordinary cases with those of its fellow of
the other side ; though I have a head before me in which
the two ranine arteries communicate by a large cross
branch at the root of the tongue. The sublingual artery
winds along the under and outer border of the tongue,
preserving a more superficial course than the former.

326 The External Carotid Artery.

It supplies the sublingual gland, and distributes its
longer branches over the membrane and papillae of the
tongue, d. The submental artery leaves the submax-
illary contiguously to the internal side of the jaw, a
little before the latter vessel begins to make its turn.
It follows the course of the branch of the jaw, nearly
preserving the line of its middle, detaching twigs prin-
cipally to the pterygoideus and mylo-hyoideus, and
transmits its furthest ramifications into the substance of
the gums internally, e. Anterior masseter branches, one
large, or two or three small vessels, coming off in the
course of its ascent upon the external side of the jaw.

The inferior labial artery courses the side
of the jaw, occupying nearly the same site externally
to what the submental does internally, invested in the
cellular and fleshy substance belonging to the buccina-
tor. It is principally destined for the supply of the
glandular substance of the under lip, wherein it anas-
tomoses with the corresponding vessel. It gives off —
a. Slender ramifications to the investing cellular sub-
stance, b. Buccinator arteries, c. A large branch to
the angle of the mouth, which distributes buccal twigs
in its course, and then bifurcates, sending its divisions
respectively to the upper and under lips, along their
lateral borders : these form the superior and inferior co-
ronary arteries of the lips.

The facial artery ascends upon the side of the
face, with an inclination forward and downward, cross-
ing the buccinator a little in advance of the anterior
border of the masseter. Having run as high as the
level of the bony ridge from which the masseter arises,
it detaches a large branch, and then winds upward and
spreads into an arborescent expansion upon the upper

The External Carotid Artery. 327

and fore part of the face. a. It mostly sends one or
two masseter branches backward. b. Buccal twigs from
both sides, c. The superior labial, the branch whose
origin has just been shown, takes its course below the
false nostril, to which it sends ramifications, to the
upper lip, wherein it anastomoses with the terminating
branches of the palatine arteries and with its fellow.
d. Long slender branches, commonly two, to the false
nostrils, e. Terminating ramifications to the cellular
substance and skin covering the fore part of the face,
which anastomose with others making their exit from
the infra-orbitar foramen, and also with some straggling
twigs escaping from the cavity of the orbit.

2. The parotideal branches are those we may
consider next to the submaxillary branch of the exter-
nal carotid. They are too variable in number, size,
and mode of origin, to admit of particular descriptions :
they come off as the vessel continues its course under
the gland.

3. A large branch, internally, to the pterygoideus.

4. One much longer, externally, the posterior mas-
seter artery.

5. The posterior auricular commonly comes
off immediately opposite to the last-mentioned branch .
It emerges from underneath the parotid gland, and as-
cends in a direct line to the back of the concha of the
ear, where it splits into three divisions, which thence
proceed along its dorsum to its tip, distributing branches
right and left which anastomose freely with one another
and the other auricular arteries, and thereby form a
beautiful vascular network. It gives branches to the
parotid gland, muscles of the concha, meatus audito-
rius externus, and raembrana tympani.

328 The External Carotid Artery.

6. The temporal artery, the anterior auri'
cular, and the internal maxillary, may be considered
as the terminating branches of the external carotid.
The temporal leaves the trunk just as it is emerging
from the depth of the parotid gland, curves upward
and forward around the neck of the jaw, a little below
the condyle, which serves as a guide to cut down upon
it; from this, it runs in a straight line towards the
outer circumference of the orbit, just opposite to which
margin it dips into the substance of the masseter so as
to elude further trace without the aid of dissection.
We find it henceforward corresponding in course to the
line of the maxillary ridge, sending branches down to
the muscle, and freely anastomosing with the anterior
and internal masseter arteries.

.il7. The anterior auricular artery, arising
in common with the former, inclines in an opposite di-
rection, upward and backward, and is deeply seated at
first under the parotid gland. It ascends to the fore
part of the root of the ear, and ends in short ramifi-
cations to the anterior muscles of the concha, and in
other superficial ones which anastomose with the an-r
terior auricular arteries. It sends off — a. Branches to
the temporal muscle, b. An internal auricular branch,
which enters the concha. c. A subcutaneous branch,
which descends upon the forehead and anastomoses with
the supra-orbitar arteries.

8. The internal maxillary artery is deeply
placed to the inside of the articulation of the jaw, a
little below the condyle, between the neck of the in-
ferior maxilla and the upper extremity of the cornu of
the OS hyoides. It pursues a winding course, first
bending inward then downward, to the bottom of the

The External Carotid Arlerif. 329

orbit, where it separates into four arteries. In its way
to the orbit, it gives off— 1. Deep temporal branches,
several small arteries, variable in number, some of
which run into the pterygoid muscle, while others,
longer ones, ascend in the space behind the orbit, ra-
mifying within the adipose matter there, and penetrat-
ing the lower portion of the temporal muscle.

2. Long slender twigs to the soft palate, to the ear,
and to the articulation of the jaw.

3. The inferior maxillary^ a small artery of consider-
able length, which creeps down the branch of the jaw,
crossing the pterygoid muscle, to enter the foramen
maxillare superius in company with the nerve of the
same name ; within which canal it distributes branches
to the roots of the molar teeth and to the diploe, and
then makes its exit, greatly diminished in size, through
the foramen maxillare inferius, upon the side of the
mouth, where it is lost in anastomosis with the inferior
labial artery : in some instances, the latter artery sends
a twig into this hole in place of one coming out. The
vessels in which the internal maxillary terminates are —

4. The supra-orbitar artery, which traverses the
upper and inner part of the roof of the orbit, and leaves
the cavity through the foramen supra-orbitarium, and
is lost in slender ramifications in the cellular membrane
upon the forehead, anastomosing with the temporal
branches of the anterior auricular, and ascending deep
temporal arteries.

5. The ocular, under which name are included a
bunch of arteries arising from the bottom of the orbit,
which are distributed to the fatty matter thereabouts,
to the muscles of the globe, and to the lachrymal gland,

330 The External Carotid Artery.

eyelids, and ductus ad nasum. One in particular,
larger than the others, named the lateral nasal branch,
enters the cavity of the cranium through the foramen
orbitale internum, and after forming a communication
there with the anterior cerebral artery, turns round and
enters the nose through the ethmoidal cells to be dis-
persed upon the Schneiderian membrane.

^6. The infra-orbitar, a considerable branch which
enters the infra-orbitar canal, in order to supply the
anterior molar teeth and medullary substance of the
bone with blood : having served this purpose, it sends
its remaining twigs out upon the cheek, through the
maxillary hole there, where they anastomose with the
ramifications of the facial artery.

7. The palato-maxillary, the largest of the terminat-
ing divisions of the inferior maxillary artery, enters the
foramen palatinum superius, descends through the pa-
latine canal, re-appears upon the roof of the palate,
and follows the tract of the palatine groove, some
short distance removed from the sides of the molar
teeth, and inferiorly makes a curve inward, just above
the roots of the front teeth, to take its passage through
the foramen incisivum, in front of which it joins its
fellow : from this remarkable arterial union issue seve-
ral branches, some of which run down to supply the
glandular structure of the upper lip, while others are
directed upward upon the external nares, and the deep-
seated ones penetrate the dilatator narium and depres-
sor labii superioris; many of them anastomose with
the terminating ramifications of the superior labial
artery. This artery gives off some few branches to
parts at the back of the orbit, before it enters the fora-

Ramus Anastomoticus. 331

men ; and other short twigs, as it courses the palate. —
Sportsmen and farriers have a practice of cutting
through the bars and severing this vessel in order to
detract blood on any occasion of emergency : the ar-
tery however seldom bleeds much — it soon retracts into
its cellular case and fonns a coagulum, on which ac-
count the operation is, generally speaking, both harm-
less and ineffectual.

The second and smallest division of the external
carotid is the

Ramus Anastomoticus.

It leaves the trunk of the carotid, commonly at the
angle formed by the external and internal carotids,
crossing the latter in proceeding to the spine. Deeply
seated under the parotid gland, in its course it describes
an are backward, which, in the ordinary position of the
head, nearly corresponds to the under border of the
stylo-maxillaris. From below the coronoid or styloid
process, it turns under the transverse process of the
atlas, where it joins the vertebral artery, as soon as the
latter has passed through the foramen in that bone.
From about the middle of the arch comes off

The occipital artery, a vessel nearly equal in
magnitude to the trunk itself, which pursues a flexuous
course to the occiput, first ascending upon the coronoid
process, and then climbing the occipital ridge to reach
the vertex. Its branches are — 1. A long, slender,
deep-seated one, which mounts upward and enters the
cranium through the foramen lacerum to be dispersed
upon the dura mater : this is sometimes a branch from
the anastomotic trunk. 2. Twigs forwarded to the

332 Internal Carotid Artery.

temporal muscle. 3. Terminating ramifications to the
straight and oblique muscles of the occiput.
The third division of the carotid is the

Internal Carotid Artery.

This vessel, whose calibre is not more than half that
of the external carotid, is deeply lodged within the
submaxillary space, whence it ascends to the base of
the skull, crossing the upper extremity of the cornu of
the OS hyoides inwardly in its course, which is rendered
remarkable by several tortuous turns : it first curves
backward, next inward, then upward, and lastly for-
ward, to reach the anterior part of the foramen lace-
rum, through which it enters the cavity of the cranium.
It is accompanied in its course by one of the princi-
pal forming branches of the jugular vein, by the eighth
pair of nerves, and by the sympathetic. At its en-
trance into the skull, we find the artery lodged within
the cavernous sinus, wherein it makes two more turns,
one forward, the other inward, from which last flexure
comes off a vessel named the

1. Arteria communicans, which runs in a direc-
tion upward and backward, passing under the crura
cerebri, to join the basilar, with which it makes one
continued vessel, thus forming one side of the circulus
arteriosus, to be presently described. — After having
given off this vessel, the internal carotid pierces the
dura mater, and takes its course upward alongside of
the optic nerve, and just over the optic decussation
splits into four principal divisions. At the point of
division however, or prior to it, are sent off— 2. Two
or three long branches of small size which run forward

Interna/ Carotid Arleri/. 333

and spread their ramifications upon the anterior and
inferior portions of the dura mater.
The four principal divisions are

1. The anterior cerebral, which advances by
the side of the optic nerve, and in front of its decussa-
tion transmits a considerable branch across, which unites
with a similar one coming from the opposite division,
thereby forming a vessel nearly equal in size to the
internal carotid itself, named the arteria corporis callosi :
this is reflected upward and forward around the corpus
callosum, and pursues through its entire length the
tract of the raphe, detaching as it proceeds numerous
lateral twigs for the supply of that body. The ante-
rior cerebral artery now subdivides into several branches,
which, with the exception of one, are distributed over
the anterior lobes of the brain. This one,

The opthalmic artery, leaves the cranium through
the foramen lacerum orbitale, in company with the
nerve of the same name, and, at the bottom of the or-
bit, after forming some anastomoses with the orbital
artery, furnishes a twig to the lachrymal gland, long
ciliary arteries to the choroid coat and iris, and the
central artery of the retina.

2. The middle arteries of the cerebrum,
which come off together at right angles from the trunk,
take a flexuous passage between the anterior and
middle lobes, and ramify extensively within their sub-
stance.

3. The internal artery of the cerebrum,
which arises a little higher than the former, pursues the
course of the tractus opticus, and winds round to the
tubercula quadrigemina.

334 Vertebral Artery.

The remaining vessek of the brain are derived from
the

Vertebral Artery.

This artery enters the cranial cavity through the
foramen magnum, and makes its appearance upon the
cuneiform process of the occipital bone, where, about
opposite to the middle of the medulla oblongata, it
unites with its fellow, the two forming a shigle trunk
denominated the basilar artery. The vertebral itself
o-ives off — 1. Posterior arteries to the dura mater. 2.
Ramifications to the medulla oblongata.

The BASILAR ARTERY SCUds ofF —

1. The posterior arteries of the cerebel-
lum, which leave it as it passes under the medulla
oblongata, wind upward round that body, and cross
over to the cerebellum, to the posterior portions of
which they are distributed. — The basilar artery then
continues its course under the tuber annulare, detaching
lateral branches as it advances, and next passes be-
tween the crura cerebri, where it bifurcates. Its bifur-
cations proceed but a short way before each of them
subdivide into two vessels : one runs forward to meet
the communicating artery ; the other is the

2. Anterior artery or the cerebellum,
which winds outward, around the crura cerebri, thence
crosses to the cerebellum, and is principally expended
within its lateral lobes. — Below the origin of this ar-
tery, from the sides of the arterial circle come off three
or four considerable branches, the principal of which is
the

Posterior artery of the cerebrum. This

Vertebral Artery. 335

is directed obliquely backward, across thecrus cerebri
and tractus opticus, and then mounts upon the pos-
terior lobe of the cerebrum and distributes its ramifi-
cations.

The circulus arteriosus, then, is completed
anteriorly by the transverse branch of the anterior cere-
bral divisions ; laterally, by the cormnunicating arteries ;
and posteriorly, by the bifurcations of the basilar artery.

LECTURE LXXI

r-rf *^»^»

J%e Posterior Aorta, ''^

Considerably longer and larger than the ante-
rior, is the main trunk from which are derived the
arteries of the abdomen, pelvis, and posterior extremi-
ties, in addition to the posterior intercostals and some
few of the thoracic arteries. It commences opposite to
the fourth dorsal vertebra, at some little distance re-
moved from the spine ; from its origin, it curves first
upward and then backward, having the pulmonary
artery on its left, the termination of the windpipe on
its right ; having reached the bodies of the dorsal ver-
tebrae, it enters the superior mediastinum, and afterwards
takes a straight course along the spine, inclined to the
left side, having now the esophagus and vena azygos
to the right, the thoracic duct to its left. This portion
of the vessel, often distinguished as the thoracic
AORTA, gives rise to many branches, but they are but
small. '*
1. The bronchial arises from the inferior part of
the curvature of the trunk, bends its course downward
and forward to the root of the left bronchial tube,
where it divides into two—the right and kft bronchial

The Po.alerior Aorta.

337

arteries. These vessels penetrate the lungs in company
with the bronchiae, to the branches of which they cling
in the course of their ramification within the substance
of the parenchyma.

2. The esophogeal also springs from the conca-
vity of the arch, near to the former, sometimes before
it, and then proceeds backward and to the right, to
reach the esophagus. Here it splits into a superior and
iiifetior artery, which course the entire length of the
tube, distributing branches right and left over its sur-
face, and terminating at the cardiac orifice in anasto-
mosis with the gastric artery.

3. The intercostal, the remaining branches, come off
in pairs from the sides of the vessel, to supply all
those intercostal spaces posteriorly to the last, which
received a branch from the anterior intercostal artery.
These arteries preserve the lines of the ribs, running
close to their posterior borders, and end about the infe-
rior parts of the chest and abdomen in anastomosis
with the internal pectoral and epigastric arteries. They
furnish, near their origin, small branches which enter
the vertebral canal through the spinal holes, and also
numerous muscular twigs during their course.

Having detached these small vessels, the posterior
aorta continues its passage between the crura of the
diaphragm into the abdomen : in makhig its exit from
the chest however it gives rise to two small arteries, or
to a single branch which afterwards forms two, named
the

Phrenic or diaphragmatic arteries, right
and left. These vessels penetrate their respective crm-a,
in whose substance they ramify, and ultimately dis-
appear upon the cordiform tendon. Within the abdo-

part III. z

338

The Posterior Aorta.

men, the aorta continues to be firmly fixed to the spine
by means of its several vessels and cellular attach-
ments, and thus proceeds, still inclined to the left side,
as far as the last lumbar vertebra, under the body of
which it splits into four large arterial trunks. Prior to
this division, the abdominal aorta gives off —

1. The c(eliac artery, which is nothing more
than the common root of the splenic, gastric, and he-
patic— arteries that in some instances have separate
origins : it is springing from the under part of the
trunk, a little posteriorly to the origin of the phrenic.

2'he splenic artery, the middlemost of the divisions
of the coeliac, takes a winding course to the left side
of the cavity, turns forward along the greater curvature
of the stomach, running between it and the concave
part of the spleen, and at length ends in the left gastric
artery. Soon after its origin, it gives two or three pan-
creatic arteries as it passes that gland. Many consi-
derable branches to the spleen from the convexity
of its flexure ; whilst, from the concavity of it are
passing smaller but longer branches upon the greater
curvature of the stomach. It is prolonged beyond the
tapering termination of the spleen, distributing shorter
branches to the stomach as it proceeds, and continuing
to encircle the organ towards its right extremity, from
which is coming to inosculate with it, ^he right gastric
artery.

b. The gastric artery, the smallest of the ccEliac divi-
sions, runs forward to the small curvature of the sto-
mach, between the layers of the omentum, splitting
before it reaches the organ into two branches that take
the names of superior and inferior gastric : they spread
their ramifications, in an arborescent form, upon the up-

llie Posterior Aorta. 339

per and under surfaces of the stomach, and they anas-
tomose with those of the right and left gastric.

c. The hepatic artery, the largest of the cccliac divi-
sions, proceeds before the pancreas to the right side of
the cavity, and winds forward over the pyloric end of
the stomach. It gives off — 1. Divers small branches
to the pancreas, as it passes by the gland. 2. Near the
pylorus, it sends a considerable branch to the beginning
of the duodenum, which, as soon as it reaches the in-
testine, bifurcates : one division, the duodenal, retro-
grades along the gut, and ends in anastomosis with
branches coming from the anterior mesenteric ; the
other, the right gastric, crossing the gut, proceeds to
the great curvature of the stomach, where it inosculates
with the left gastric. The hepatic artery itself is conti-
nued forward to the porta of the liver, where it divides
into the right and left hepatic: the right, the larger
and shorter one, after giving off a considerable branch
to the portio media, turns back to reach the right lobe ;
the left also gives off a branch or two to the middle
portion, but they are but small, and then runs to the
left, along the left fissure, to penetrate the other lobe.

2. The anterior or great mesenteric is the
next vessel to the cceliac, a little behind which it is
arising from the under part of the posterior aorta. The
trunk of this artery is extremely short ; but it is of
large size — aneurismal indeed in the ass species, and is
the parent stock of a numerous collection of extensive
ramifications. From its origin it passes directly down-
ward within the layers of the mesentery, detaching
from behind some slender twigs to the pancreas in its
descent, and then suddenly separates into a set of
larger branches, (commonly from eight to twelve in

7/2

•

340 The Posterior Aorta.

number) varying in length and size, from which are
derived— fl. A branch that runs to the duodenum, vv^ith-r
in the concavity of M^hich it divides into two small
ones, which turn in opposite directions and form arches,
one with the duodenal artery, the other with the next
mesenteric, from the convexities of which arise other
small transverse vessels, which encircle the intestine
and ramify to great minuteness under its peritoneal
covering, forming altogether a beautiful vascular net-
work, b. A collection of branches of considerable
length, more uniform than the rest, run backward for
the supply of the other small guts : these in like man-
ner run in arches and inosculate, and furnish an abund-
ant supply of nutrient and secerning vessels, c. Two
branches, shorter than the others, proceed to the cos-
cum caput coli, whence they run along the sides of the
coecum, sending off numerous transverse branches
which encircle the gut and anastomose freely witli
each other, d. Several long and short branches to the
colon, which furnish with lateral ramifications, distri-
buted after the same manner, the ccecal portion of the
gut, and its two great flexures or arches : the last of
these branches, which is directed towards the sio-moid
flexure, is met in anastomosis by the first of the pos-
terior mesenteric.

3. The renal or emulgent arteries leave the
aorta at right angles, one on each side, either immedi-
ately opposite or somewhat posteriorly to the origin of
the preceding vessel. They pass in straight lines di-
rectly outward, and each enters the notch of its appro-
priate kidney, and therein divides into three or four
large branches which penetrate the glandular sub-
stance. The right is the longer one, in consequence of

2

*

2'he Posterior Aorta. 341

the inclination of the aorta to the left side and its
having to cross the vena cava posterior in its course.
It furnishes in its way — a. Twigs to the enveloping
adipose membrane, h. A small artery destined for the
supply of the capsula renalis : in some instances this
last vessel comes from the aorta ; rarely, from the ante-
rior mesenteric.

4. The spermatic arteries, right and left, in
comparison to their diameter, are the longest in the
body, springing near to each other from the under part
of the aorta, about midway between the origin of the
renal arteries and its bifurcation : in some instances
these vessels come from the posterior mesenteric. They
pursue divergent and flexuous courses backward, pass
out of the abdomen at the internal abdominal rings,
and there enter into the constitution of the cords with
which they proceed to the testicles. In the female,
these arteries run within the layers of the broad liga-
ments to the ovaries to which they are principally dis-
tributed ; but they also transmit branches to the Fallo-
pian tubes and to the horns of the uterus.

6. The posterior or small mesenteric, the
last of the abominal arteries, a much longer vessel than
the anterior mesenteric, comes from the under part of
the aorta, commonly very near to the roots of the sper-
matic arteries. It descends within the folds of the
mesocolon, and distributes its principal branches to the
left — to the sigmoid flexure of the colon ; the others
run backward and ramify upon the anterior portion of
the rectum : their arrangement and distribution are
similar to the colic ramifications of the anterior mesen-
teric. The anterior division anastomoses with the pos^

342 The Internal Iliac Arteries.

terior of the great mesenteric ; and the posterior forms
communications with the other arteries supplying the
rectum.

6. Five or six pairs of lumbar arteries,
according to the number of vertebrae, are also fur-
nished by the posterior aorta. Arising in pairs from
its sides they wind upward, covered by the psoas par-
vus, follow the inter-vertebral spaces, pierce the fibres
of the intertransversales lumborum, and ramify and
expend their branches among the muscles covering the
loins. In the course of their ramifications they con-
tract communications with the last of the intercostals
and circumflex of the ileum. Near their origins, each
detaches a branch which enters the vertebral canal by
the correspondent spinal foramen, also twigs to the
psoas parvus and intertransversales.

Under the last lumbar vertebra the aorta bifurcates
into two pairs of large and important arterial trunks : —
the external and internal iliacs.

The Internal Iliac Arteries

Arise by a kind of second bifurcation from the
trunk ; for there is still a continuation of the aorta
after it has given off the external iliacs ; and this forms
a remarkable difference between it and the division of
the corresponding vessel in the human subject, the
horse having no common iliac arteries. The internal
iliacs, though larger than the external, are extremely
short ; they diverge from the parent trunk backward
and outward, and hardly quit the body of the vertebra
before each gives off a large branch, the artery of the
bulb ; it then runs a little further, and by the side of

*

The Internal Iliac Arteries. 343

the sacral articulation splits into three nearly equal
divisions : — the obturator, gluteal, and lateral sacral
ai'teries.

The artery of the bulb, I repeat, springs from
the under and outer part of the internal iliac, and then
runs backward along its outer side, where we find it
placed between the trunk and the external iliac vein,
which latter at the same time is a little above it. It
makes a sweep backward, around the sides of the pelvis,
to which it is closely bound by peritoneum and cellular
adhesions, then insinuates itself between the laminae of
the sacro-sciatic ligament, and continues along the
upper border of the ischium to the ischial arch, the
side of which it turns round to reach the bulb of the
penis, wherein it terminates. In the female, this ar-
tery sends its terminating branches to the bulb of the
vagina and lining membrane of that canal. It gives
off — 1. The umbilical artery, or rather the remains of
that vessel, which in the foetus nearly equalled in size
the iliac arteries themselves, and was surpassed by
none in regard of importance. In the young subject
these vessels commonly remain pervious as far as
the bladder ; but in process of time they degenerate
into the round ligaments of the bladder ; in the descrip-
tion of which organ notice has already been taken of
them. 2. Sundry small vesical branches, in passing, to
the bladder. 3. In leaving the pelvis, the prostatic
artery, which detaches twigs to the vesiculae seminales,
but distributes its ultimate ramifications to the pro-
strates. 4. Divers branches, anal and perineal, to the
posterior portion of the rectum, anus, and parts com-
posing the perineum.

344 The Internal Iliac Arteries.

The obturator artery, the lowermost of the
divisions of the internal iliac, corresponds in the first
part of its course to the brim of the pelvis, in which it
is accompanied by the crural nerve ; it subsequently
inclines upward to gain the posterior nook of the fora-
men obturatorium vel magnum, where it runs through
the perforation in the obturator ligament. It then
turns round the branch of the ischium, and in front
of the bone ends in division into the ischiatic, pubic,
and internal pudic arteries. Its branches are — 1. The
arteria innominata, one of very large dimensions which
comes off not far from its origin from the iliac. This
proceeds backward and outward, close under the pelvic
margin, crossing obliquely the external iliac artery and
the pso8B and iliacus muscles, and dips deeply into the
substance of the haunch, wherein it sends branches
downward to the rectus, upward to the tensor vaginae.
2. Ramifications to the obturator muscles and ligament,
in passing through the foramen. Its divisions are —
1. The ischiatic, which turns down upon the back of
the haunch, passing opposite to the hip-joint, and dis-
tributes its branches to the triceps. 2. The pubic runs
backward along the branch of the ischium, and is
expended in the large head of that muscle. 3. The
internal pudic artery turns inward and backward round
the ischial arch to the root of the penis, where it splits
into two sets of branches, a. One set penetrate and
end in the crus penis. h. Two or three branches
belonging to the other set run further forward and
pierce the fibrous case of the corpus cavernosum. c.
One or two slender branches of the same run along the
dorsum penis, d. Another accompanies the pudic

The Internal Iliac Arteries.

345

nerve to the extremity of the oroan. e. Besides which
there are sundry cutaneous twigs.

The gluteal artery, the middlemost of the iliac
divisions, shortly after its origin leaves the pelvis through
the hole in the sacro-sciatic ligament, at the anterior
nook of the notch, in company with the sciatic nerve,
which runs behind it : immediately that it has made
its exit, it splits into two or three branches of large
size whose ramifications are destined principally for the
gluteal muscles, though some descend to aid in the
supply of the posterior femoral muscles.

The lateral sacral artery runs directly back-
ward, following the sides of the sacrum, to which being
closely bound by cellular adhesion it necessarily takes
the slight curve of that bone : having reached the
coccyx it splits into two long, slender, terminat-
ing branches. It furnishes — 1. Sacrospinal branches,
five or six in number, which enter the spinal canal
through the internal sacral foramina. 2. The peroneal
artery, a branch as large as, or even larger than,
the trunk itself, of which it might be more correctly
perhaps considered as the continuation. It soon di-
vides into several ramifications, of which — a. many
run to the gluteal muscles ; b. while others descend
upon the back of the thigh ; c. and a third set are dis-
tributed to the anal muscles, and to the skin and cel-
lular substance of the perineum. 3. The lateral coccy-
geal artery, one of the terminating branches of the la-
teral sacral, runs close to the side of the os coccygis,
even to its extreme point, preserving the line of direc-
tion of the trunk, diminishing in diameter as it re-
cedes, and distributing numerous branches laterally to

346 The External Iliac Artery.

the Coccygeal muscles. 4. The inferior coccygeal artery,
rather larger than the lateral, takes the same course
along the inferior and lateral part of the bone, and may
also be traced to the tip. It sends down a long slender
twig or two to the anus ; the remainder of its branches
are distributed to the coccygeal muscles.

The middle sacral artery is a very inconsi-
derable branch coming off, generally, from the trunk at
its angle of bifurcation into the internal iliacs. It pro-
ceeds a little way backward upon the middle of the sa-
crum, and then vanishes.

The External Iliac Artery ,

Right and left, results from (what may be significantly
described as) the frst bifurcation of the posterior aorta,
which takes place underneath the body of the last of
the lumbar vertebrae. It takes the same oblique direc-
tion (outward and backward) as the internal iliac, but
it is less in diameter, and bears no comparison in re-
spect to length. The best guide to its situation is the
brim of the pelvis ; considering the bowels to be re-
moved, it runs along this brink of the cavity, uncovered
by any thing but peritoneum, following the bony cur-
vature outward to its termination, which we mark upon
the same brim about midway between the symphysis
pubis and anterior spinous process of the pelvis, from
which place it plunges into the prominent mass of mus-
cle forming the inside of the thighs. The vessel gives
off—

1. The circumflex artery of the ileum, a
large branch that departs from the outward side of the
trunk, near its origin. It winds directly across the loins

Th£ External Iliac Artery. 347

to the flank, covered only by peritoneum, crossing in
its way the two psoas and the iliacus ; ariving in front
of the anterior spinous process of the os innominatum,
it spHts into two vessels, which take opposite courses :
one inclines backward, penetrating the transversalis, to
which and to the originating portion of the internal ob-
lique muscle its ramifications are distributed ; the an-
terior and longer division curves forward between the
transverse and internal oblique muscles, and sends its
ramifications to them, but principally to the latter, with
the exception of its ulterior twigs, and they run on and
form communications with the last intercostals. These
vessels also anastomose, among the muscles, with the
lumbar arteries.

2. The artery of the cord, which in other
cases comes from the last-described branch, or from the
aorta itself, arises from the under part of the vessel, a
little further backward than the circumflex. This is a
very slender vessel, but of sufficient length to run ob-
liquely backward to join the spermatic cord and proceed
with it through the inguinal canal, for the general sup-
ply of the parts entering into its constitution.

3. The arteria profunda femoris is a very
large branch which may be said at its origin to mark the
extent of the iliac artery posteriorly and the femoral
anteriorly, or one that may be considered to be given
off by either of the trunks at the place where they in-
dividually change their names. The profunda plunges
at once into the thick of the haunch, and then makes
an oblique curve round the neck of the os femoris,
passing under the short and long heads of the triceps.
Having reached the posterior quarters, it sends its ra-

348 The ExtcnuU iliac Arlery.

raifications principally into the biceps. Before this
vessel dips into the substance of the thigh it gives rise
to a large branch,

The epigastric artery, which at first makes a curve
backward, downward, and outward, in doing which it
turns round the inward margin of the internal ring,
running at the time between the peritoneum and the
tendon of the transversalis ; next, it makes a sweep out-
ward and subsequently upward, in the course of which
it gradually insinuates itself between the disgregated
tendinous fasciculi of that muscle until it at length is
found pursuing its way between the transverse tendon
and internal oblique muscle. It then continues its
passage forward, within the sheath of the rectus, along
the upper and inner border of that muscle, furnishing
as it goes ramifications from its sides, and at length
ends in anastomosis with some ramifications coming in
a contrary direction from the internal pectoral. In
passing the ring, it gives origin to a considerable branch
which turns round the crescentic borders of the ten-
dons forming that aperture and then splits into several
small arteries. Of these — a. A twig runs to the groin
and ramifies among the adipose membrane and absor-
bent glands there, b. A long slender branch makes
it* way to the ring and descends upon the cremaster;
this is furnished however in some instances by the ex-
ternal iliac, c. A subcutaneous twig to the thigh, d.
The external pudic, the largest and longest of these di-
' Visions, when this is their arrangement, for the origin of
these vessels is attended with much variety : it runs
forward, invested in the subcutaneous cellular substance
of the scrotum, sending ramifications to the tunica va-

The Femoral Artery. 349

ginalis, and the skin, and continuino- forwardjiipon the
penis, where it inosculates with the superficial rami-
fications of the internal pudic.

The Femoral Artery.

Regarding the profunda femoris as a limb of the
external iliac, we descend to the femoral artery, the
subsequent continuation of the same trunk. This ar-
tery proceeds in an oblique direction down the haunch,
preserving nearly the line of its middle ; it might ap-
pear from its origin, and from no part of it being
brought into view by the removal of the faschia, that
it directly plunged deep among the muscles ; this how-
ever is by no means the case, for the upper half of the
vessel may be considered, in an anatomical sense, as
superficial : an incision carried along the prominent
anterior border of the gracilis, separating it from the
sartorius and pushing the latter forward, at any point
in the upper half of the thigh, will immediately expose
the vessel. The beginning of the trunk, which is
curved outward, is covered by lymphatic glands of the
groin ; it is then overlapped by the thin posterior edge
of the sartorius, and subsequently by the anterior bor-
der of the gracilis, running rather below the middle of
the thigh within a triangular space formed by the ap-
proximation of the two ; here the vessel dips deeply
into the muscular substance, having the long head of
the triceps on its inner part, the bone on its outer, and
afterwards takes its course between the heads of the
gastrocnemius externus into the hollow at the back of
the stifle, wherein we find it close to the joint, but
nearer to the outer than the inner side : opposite to the

330 The Femoral Arterii.

liead of the tibia it bifurcates into the anterior and
posterior tibial arteries. The femoral trunk is accom-
panied by its vein, which is placed at first behind and
then gets to the outer side of it ; and the principal
branch of the crural nerve runs for nearly one-third of
the way along the outer side of it also : they are all three
invested in some loose cellular substance. The anterior
branches are — 1. The inguinal, one of large size arising
in the groin, covered at its origin by the lymphatic
glands, to which it sends twigs ; it then crosses under
the sartorius, to which it also sends ramifications, and
gets between the vastus internus and rectus, where it
splits into two divisions which penetrate those muscles.
2. Three or four small branches to the sartorius. 3. A
long slender one to the side and front of the stifle.
Its posterior branches are — 1. A considerable one to
the gracilis, which detaches twigs to the long and short
heads of the triceps. 2. A small one that turns in-
wardly to the vastus internus. 3. A branch supplying
both the long and large heads of the triceps. 4. One
that turns round the back of the bone about the middle
of the thigh for the supply of the biceps. 5. One
large or two smaller branches sent along the posterior
border of the gastrocnemius externus, from which re-
current ramifications ascend to the triceps. At the
back of the stifle come off* the popliteal branches, four
or five in number, taking opposite directions, which
are destined for the supply of the joint: one runs down
upon the posterior tibial muscles ; another, the recur-
rent branch, climbs the back of the os femoris and
anastomoses with the descending ramifications of the
profunda femoris.

The Tibial Arteries,

Anterior and posterior, are to be regarded in no other
light than the bifurcated continuation of the femoral
trunk : this division, I before remarked, happens at the
back of the head of the tibia.

The posterior tibial artery, the smaller of
the two, is curved outward at its origin ; it then de-
scends along the posterior deep region of the thigh,
inclining all the way from the outer to the inner side,
at first between the flexor pedis and the popliteus,
which is behind it, subsequently between the former
muscle and the flexor pedis accessorius, and at length
between the tendon of the last-named muscle and the
inner, posterior, and inferior part of the body of the
tibia. Just above the hock, it inclines inward again
and gets deep-seated between the lower end of the
flexor pedis and the bone, where it ends in bifurcation.
Its branches are — 1 . One, which comes off a short dis-
tance from its origin and runs into the flexor pedis^
2. The medullary, which enters the medullary foramen
in the upper and back part of the tibia. 3. Unim-
portant twigs to both the flexors. Of its terminating
branches — the external one proceeds round the outside
of the hock, ramifying there subcutaneously and anas-
tomosing with some articular twigs of the anterior
tibial ; the internal continues down the leg over the
tendon of the flexor pedis, within a cellular sheath
formed between that tendon and the root of the os
calcis, in company with the internal metatarsal nerve,
and creeps along the inner edge of the metatarsal bone,
between the flexor tendons and suspensary ligament,

352 The Tibial Arteries.

ending at the lower part of the cannon in divers small
ramifications. At the hock, this artery sends off one
or two recurrent branches which ascend upon the root
and back of the os calcis, and anastomose with others
coming down from the posterior tibial.

The anterior tibial artery no sooner leaves
the common trunk than it suddenly turns forward and
passes between the tibia and fibula to the fore part of
the thigh ; here we find it between two veins, crossing
with very gradual obliquity the outer part of the bone
to gain the front, which it does about midway between
the stifle and hock ; it then continues to descend be-
tween the outer border of the flexor metatarsi and the
bone until it reaches the front of the hock ; here it
makes another sweep outv^'ard, and ultimately arrives
in the channel between the external and large metatar-
sal bones, where it becomes the metatarsal artery. Its
branches are — 1. Some small recurrent articular, which
ascend to the stifle and communicate with the popli-
teal branches. 2. Various muscular branches, in its
course down the thigh. 3. Divers, small, articular
and cutaneous branches, as it obliquely winds from the
front of the hock to its outer and anterior part. 4. A
slender metatarsal artery which descends upon the front
of the cannon, adhering to the bone, along the inner
edge of the extensor tendon, whose ramifications,
mostly cutaneous, are distributed over the inner and
fore part of the leg, the terminating ones reaching as
low as the fetlock.

The metatarsal artery pursues its course,, un-
accompanied by any vein, along the above-noticed chan-
nel for two-thirds or thereabouts of the length of the.

The Tibial Arteries.

353

leg ; it then passes between the internal and large
metatarsal bones, and gains the posterior part of the
latter, between which and the suspensary ligament, a
little above the fetlock, it divides into three vessels :
one forms an arch (as in the fore extremity) from which
come off the recurrents, and they anostomose with the
posterior tibial artery ; the lateral divisions become the
plantar arteries.

Henceforward, the arteries correspond in the fore and
hind extremities ; one description therefore suffices for
both.

PART HI.

LECTURE LXXII.

Distribution of Veins.

The veins over the body generally have a similar
arrangement and distribution to tlie arteries, though
they are perhaps at least double the number of those
vessels : where we find an artery, we almost invariably
find a vein, and very frequently meet with two veins ;
besides which, there are many veins that have no ar-
teries accompanying them. In our descriptions of the
arteries, every now and then, we met with some no-
table variations from the ordinary or general distribu-
tion ; but the veins vary greatly more in their course
and division into branches than the arteries, inasmuch,
indeed, that any description of them in one subject,
however accurately drawn in that instance, will never
hardly be found correct in every particular when ap-
plied to another. Like the arteries, they are arranged
in two general systems : the one, consisting of the pul-
monary veins, exclusively belonging to the lungs, has
been already described ; the other, distributed over the
body generally, forms the subject of our present in-
quiry. With this last is connected a peculiar venous
arrangement subservient to the liver, which is often

The Anterior Vena Cava. — The Jugular Vein. 355

made a distinct consideration of, under the title of the
St/stem of the vena porta.

The two main venous trunks, the ven^ CAViE,
anterior et posterior, correspond to the anterior and
posterior aortas ; the one is the main returning venous
conduit belonging to the fore parts of the body, the
other that into which the veins ultimately run coming
from the hind parts : these trunks, with their various
ramifications, consequently, are totally unconnected,
one with the other, and this circumstance furnishes us
with a convenient division of the whole into the vessels of'
the anterior and those of the posterior vena cava.

The Anterior Vena Cava

Forms the main or common trunk of the veins re-
turning the blood from the head, neck, parietes of the
chest, and fore extremities. It is a short vessel, but
one of considerable volume, ending by a bulky termi-
nation in the summit of the right auricle, having the
trachea above, and the anterior aorta to its right, and
with both included between the layers of the medias-
tinum. The anterior cava is principally formed by the
concurrent union of the jugular and axillaty veins, and
is situated at its formation in the space between the
two first ribs, about midway between the sternum
and vertebrae ; it also receives the pectoral, vertebral,
dorso-cervical, and inferior cervical veins, and the vena
azygos, which augment its volume in its course to the
heart.

The Jugular Vein.

This forms the principal venous conduit from the
head and neck, corresponding in course and ramifica-

2 A 2

366 The Jugular Vein.

tion to the carotid ; we have therefore a right and a
left jugular vein, and it is quite unimportant which we
take by way of description. The jugular vein takes its
rise at the foramen lacerum basis cranii, from the ter-
mination there of the lateral sinus of the dura mater,
from which it receives the blood returned principally
from the cerebrum, partly from the cerebellum. Con-
cealed at its origin by the condyle of the jaw, it de-
scends to the inward side and behind the neck of the
condyle, deeply buried under the parotid gland ; lower
down, it makes its appearance behind the branch *of
the jaw, and there joins the external carotid artery,
along with which it continues its course into the neck.
In this part of its course it receives the following
branches of importance — 1. The auricular veins,
anterior and posterior, and also internal, varying in
their number and mode of termination, which are seen
descending over the root of the ear. 2. The tempo-
ral, a vein of considerable size, taking its course
along the upper side of the temporal artery. 3. The
INTERNAL MAXILLARY, a large vcin found in com-
pany with its arteiy : in its course it receives the
blood of many small veins — the palato-maxillarif, infra
and supra orhitar, ocular, inferior maxillary, and deep
temporal. 4. The parotideal, numerous veins from
the parotid, and some also from the submaxillary
gland. 5. Branches from the masseter and pterygoid
muscles.

6. The occipital vein, a long flexuous branch
descending from the head along with the occipital ar-
teiy. It brings blood from the occipital sinuses, re-
ceives veins from the posterior lobes of the cerebrum,
and from the cerebellum ; also veins from the dura

The Jugi(/ar Vein. 357

mater, and several muscular branches in the course of
its descent.

7. The submaxillary vein, the most consider-
able branch of the jugular, so large indeed compared
to the continued trunk that some regard the two toge-
ther as a bifurcation of the common jugular. It is
formed upon the side of the face by the concurrence of
the facial, labialy and varicose veins, whence it turns
round the branch of the jaw, between the artery of the
same name and the parotid duct, and joins the trunk
by the side of the trachea, just below the parotid
gland. In its course it receives other veins which like-
wise contribute to its volume, of which the principal
are — the submental, sublingual, lingual, phajyngeal, and
superior laryngeal veins. The facial vein results from'
a ramous expansion of small veins upon the side of the
face, receiving one or two branches, one of which i»
commonly varicose, from the masseter. The labial vein
is formed by the union of a plexus of venous branches
coming principally from the angle of the mouth, joined
by others both from the upper and lower lips. The
varicose vein is a vessel deeply buried in the substance
of the masseter, descending obliquely along the furrow
made by the approximation of the jaws when the
mouth is shut, and is one remarkable for having na-
turally a large varix or reservoir for blood at its origin :
not however that this is the only varicose vein, for the
temporal commonly bulges more or less, as well as a
vein from this muscle already noticed ; but this is the
largest specimen of so remarkable a formation. I believe
that these varices serve to guard against stagnation or
congestion in the brain and its membranes, and from

358 The Jugular Vein.

consequent rupture of their sinuses and delicate veins,
by receiving the blood at the time that the circulation
is interrupted or impeded from the motions of the jaw.

The jugular trunk having received the submaxillary
vein in the space between the larynx and vertebra den-
tata, proceeds down the side of the neck, covered by
the cervical portion of the panniculus carnosus, within
the channel fonned by the lower border of the levator
humeri and the upper one of the mylo-hyoideus ; by a
layer of oblique fibres coming from the former of which
muscles it is separated from the carotid artery and
trachea, which run to its inward side and rather below
it; in its course down the lower half of the neck how-
ever it gets deeper-seated, approaches the windpipe,
and afterwards runs in company with the carotid ar-
tery. It terminates in the anterior vena cava within
the space between the two first ribs. At or near the
junction of the submaxillary, the jugular vein receives
some small veins, principally thyroideal ; during its
course it also receives many small branches — cutaneous,
muscular, and tracheal veins. Near its termination it
receives a considerable branch, the superficial brachial
vein, which arises in front of the radius, about two-
thirds of the length of the bone upward, from the main
brachial vein, and ascends along the anterior border of
the biceps, and continues upward in the hollow between
the breast and the arm, winding as it proceeds a little
outward, to reach the jugular: this by farriers is called
the plat-vein— \t is the one we are in the practice of
opening for lameness in the shoulder. It receives some
unimportant muscular and cutaneous branches in the
course of its ascent.

359

The Vertebral Vein

Is the fellow vessel to tJie vertebral artery, taking the
same course, on either side of the neck, from the head
to the chest, through all the foramina in the transverse
processes of the cervical vertebrce with the exception
of the last. This vein has communications with the
occipital sinus and posterior cerebral veins, but it owes
its formation principally to the veins coming from the
medulla oblongata, and the spinal marrow and its
membranes : it also receiTes vessels from the deep-
seated muscles in the vicinity. It takes its course
along the upper side of the vertebral artery, and ends
in the anterior vena cava, just behind the first rib.

The Axillary Vein

Forms the main channel for the return of the blood
distributed by the divisions and ramifications of the
axillary artery (to which it corresponds) to the various
parts of the fore extremity. Its forming branches may
be arranged into sets, a superficial and a deep-seated
set : the former run for the most part immediately
underneath the skin ; the latter, exceeding them in
number and size, accompany the arteries among the
muscles ; we meet however with divers vessels of com-
munication between them in their course. It will faci-
litate the description of these vessels, and be the most
natural mode of proceeding, for us to descend at once
to the foot and trace them from their origin ; I shall
therefore first direct my attention to the

Plantar veins. There is not perhaps a piece of
vascular structure in any part of any animal that, can
be exhibited as a specimen of greater beauty of venous

360 The Axillary Vein.

arrangement than the foot of the horse : the sole dis-
plays a curious and intricate network of small veins,
and the laminae in every part show the same reticular
venous ramification, altogether giving the foot really
quite a covering of venous netting. We have seen
that the arteries of the foot elude pressure, and conse-
quent impeded or interrupted circulation, by running
through the interior of the os pedis ; we now perceive
that the veins, running all outside, (for, to have ad-
mitted them also through it, the bone must have been
perforated in so many places that it would have been
inadequate to the superincumbent burden,) guard
against the impediments necessarily occasioned to the
circulation in some of them by the numbers of commu-
nicating canals which are provided in every direction :
in addition to which, we may recall to mind, that they
have no valves. ,

The veins of the sole pour their blood into the veins
of the laminae, with the exception of some few of the
posterior most, and they end in the veins of the frog.

The veins of the lamina increase in size towards the
coronet, and gradually unravel themselves so as to col-
lect into a great many plexuses or bunches ; these run
directly upward, crowd through the substance of the
coronary ligament, and afterwards form the superficial
coronary vein. From them, larger branches proceed
laterally which are again joined in communication
by the deep coronary, a vein commonly double ; after
which, the larger veins upon the sides diminish in
number, and all conjoin into two or three branched
which, opposite to the pastern-joint, unite into a single
vein.

The veins of the frog, after ramifying in the form

The AxUlarif Vein. 3^

of network over that body, ascend along the inward
sides of the cartilages into the heel, converging and
growing larger as they leave the foot, and making a
single branch at the pastern-joint, which runs up and
unites, a little above the head of the os sufFraginis,
with that coming from the lamina?, thereby forming the
l)lantar vein. '^V

The plantar vein in its ascent preserves the line ill
front of the plantar arter^', accompanying that vessel
till they both unite with their fellow trunks of the bp^
posite side and become metacarpal. In itis course)'it
is joined by the perpendicular vein, besides other smaU
unimportant branches: at its termination, it receives
one or two veins of considerable size which emerge
from the fetlock-joint. '

The metacarpal veins, two in number, result
from the union of the plantar, which takes place just
over the tops of the sesamoids, in the channel between
the flexor tendons and the suspensary ligament. These
veins pursue their course up the leg, one on either side,
along the same channel between the tendons and the
ligament, to the back of the knee, where they end in
a remarkable anastomosis, which is formed by a trans-
verse branch equal in diameter to either of the trunks.
The internal metacarpal vein accompanies the artery,
having that vessel behind and the inner small metacar-
pal bone in front ; the external vein, the smaller and
deepe^-seated one, also preserves the Hne of the splint
bone on the other side, but it is more inwardly placed.
These vessels receive in their course cutaneous veins
from the front of the cannon, and at theit- origin one or
two descending veins from the back of the leg. There
is some variety commonly found in regard to the

362 The Axillary Vein.

number and disposition of the anastomosing and other
branches at the back of the knee ; but there are ordi-
narily two principal venous trunks, one of which as-
cends over the inner and back part of the joint, having
tlie artery behind it, the other mounts close to the
inward border of the trapezium. As they pass the
joint, these vessels receive the blood from the anterior
and posterior articular veins. A little above this, they
communicate by a short and free anastomosis, and
afterwards run on to form the superficial and deep-
seated veins of the aim.

The superficial brachial vein, the cephalic
of the human subject, the plat-vein of our farriers,
continues to ascend along the inner side of the radius,
inclining very gradually forward, until it has arrived
at the elbow-joint; here, it crosses obliquely over to
the front of the biceps and pursues its ascent upon
that muscle towards the point of the shoulder, to the
inner part of which it creeps round, and then plunges
inward to reach the jugular vein, in which it termi-
nates. This is one of the superficial veins of the arm,
it being covered only by the skin from its origin to
its reaching the shoulder-joint ; and is, as I observed
before, the vein we commonly let blood from. In
its course, it receives divers cutaneous and muscular
branches which contribute to augment its volume a
little ; and besides, contracts anastomoses with the
other veins of the arm, among which should not be
overlooked a large and remarkable conununication it
has with the humeral vein, just before it leaves the ra-
dius, through the medium of a branch which runs
directly upward.

The radial veins, arising from the junction of

The AiUlary Vein. 363

the metacarpal veins above the knee, two in number,
take the course of the radial artery, and a little above
the shoulder-joint concur with the anastomotic branch
coming from the superficial brachial to form the hume-
ral vein. They receive many muscular branches as
they ascend, and also anastomosing vessels from the
ulnar and superficial veins.

The ulnar veins are divers small vessels taking
the course of their respective arteries. One of them,
apart from the others, is connected with the humeral
by a separate canal, and makes a curve upon the in-
ward part of the elbow -joint towards the olecranon, and
afterwards runs down over the side of that projection
along the backs of the flexors, where it becomes super-
ficial, to its termination at the knee. The others all
end by a common trunk in the humeral vein, about its
middle.

The humeral vein, the production of the union
of the anastomotic branch from the superficial bra-
chial with the radial veins, is a large vessel extending
along the inner side of the humerus, in contact with
the bone. The humeral artery, which accompanies
this vessel, is at first concealed between the bone and
the vein, but higher up the artery gets in front of the
vein. It receives small veins from the joint, and divers
others from the muscles around, whose number is inde-
terminable, and whose course is best leamt by a refer-
ence to that of the arteries. It receives a considerable
branch from the triceps.

The axillary vein is the continuation of the
humeral, augmented by the accession of the triceps
vein. The axillary artery joins the limb directly op-
posite to the shoulder-joint, and the vein runs inime-

364

The Pectoral Veiu.

diately below and alongside of it. It follows the future
course of the artery, turning with it round the first
rib, to join the vena cava anterior, wliich it does at the
place where that vessel receives the jugular. Its
branches are — 1. The subscapular vein, one of consi-
derable size accompanying the subscapular artery, re-
ceives as it runs along branches from the triceps and
subscapularis, corresponding- to the arteries, and either
joins the root of this vein or the termination of the
humeral. 2. The dorsalis scapula follows the course of
the artery of that name, bringing blood from the antea
and postea spinati, and terminates about midway be-
tween the chest and shoulder. The remaining branches
of this vein come from the parietes of the thorax.
They are — a. The humeral thoracic, comprising two or
three veins, corresponding to the arteries so called, the
original ramifications of which come from the muscles
^bout the point of the shoulder, b. The external iho'
rack is a long vein traversing the lower part of the
chest, in a horizontal direction behind the arm. A
great portion of it runs subcutaneously, and is dis-
tinctly traceable in the living animal through the skin,
from which circumstance it has been noticed by horse-
men and named from its situation the spur vein. It is
originally formed upon the abdominal parietes by the
union of two convergent branches, which are derived
from the integuments of the sheath, or, in the female,
the mammae : it receives also, as it crosses over the
ribs, other small veins which likewise contribute more
or less to its volume.

The Pectoral Vein
Answers in cour.se and distribution to the pectoral

The Dorso-Cemical 6f Inferior Cervical Veins. 365

artery. It originates in branches from the abdominal
parietes, continues to receive laterally accessory vessels
in its course, and ascends along the inner and posterior
border of the first rib, in front of the artery, to reach
the lower side of the vena cava anterior.

The Dorso-Cervical Vein

Consists of two divisions ramifying with the dorsal
and posterior cervical arteries, and bringing blood from
the muscles which they supply. It also receives the
anterior intercostal vein, the companion of the artery
so named, which is the common trunk of the veins
belonging to the second, tliird, fourth, and fifth inter-
costal arteries.

The Inferior Ceivical Vein

Is the vessel or vessels running down the inferior
part of the neck in company with the inferior cervical
artery. The principal branches are muscular, though
some come from the skin and absorbent glands in the
vicinity.

The Vena Azygos.

The last and only single branch of the vena cava an-
terior, in the upper and back part of which it ends, just
as the trunk opens into the auricle. It arises, as far
backward as the loins, by some small straggling veins,
and takes its course across the bodies of the dorsal
vertebrae, on the right side of the posterior aorta, grow-
ing somewhat larger as it advances towards its termi-
nation, where it forms a remarkable curvature down-
ward, to reach the trunk. It receives at its origin
many veins from the neighbouring muscles, those of

366 The Vena Azygos. — The Posterior Vena Cava.

the loins in particular ; but its destined office is to
bring the blood from the posterior intercostal veins —
from 12 to 13 of them on the right side, from 8 to 9
only on the left, in consequence of its being placed
itself inconveniently for the reception of more of the
latter : had the vena cava posterior been placed along-
side of the posterior aorta, a vena azygos would not
have been required ; it may be said, therefore, to sup-
ply the want of that vessel along the spine.

The Posterior Vena Cava.

This is the correspondent venous trunk to the pos-
terior aorta, returning the blood from the parietes of
the abdomen and pelvis, the urinary and genital or-
gans, and the posterior extremities. The internal and
external iliac veins, unlike their accompanying arteries,
join and form two common iliac trunks, from the
union of which, upon the last vertebra of the loins,
results the main trunk now under consideration.
Thus formed, it takes its course under the bodies
of the lumbar vertebrae, runs along the great fissure
of the liver, perforates the cordiform tendon, and
pursues its way directly across the cavity of the chest
to the posterior and inferior part of the right auricle.
In its passage it is joined by the lumbar, spermatic,
renal, hepatic, and diaphragmatic veins.

The lumbar veins, correspondent in number and
course to the lumbar arteries, result from the union of
small veins coming from the muscles clothing the loins ;
they receive in their subsequent passage, each of them,'
a branch emerging from the vertebral canal, and after-
wards join the main trunk at right ano-les.

The spermatic vein ascends in company with

The Common Iliac Veim. 367

its artery, runs forward with it within the abdomen,
and terminates in the under side of the vena cava pos-
terior, occasionally uniting first with its fellow into one
common vessel.

The renal or emulgent veins, formed by
branches emerging from the pelvis of the kidney, which
commonly exceed in number the divisions of the ar-
tery, accompanies the renal artery to the spine, and
ends in the under and outer part of the main trunk.
The left vein is longer than the right in consequence
of having to cross the aorta. They receive the veins
belonging to the capsulee renales.

The hepatic veins, many in number, spring from
the terminations of the vena portse and hepatic artery,
pervade the parenchyma of the liver, and end in the
vena cava, as it runs along the great fissure, by nume-
rous orifices resembling pinholes.

The phrenic or diaphragmatic veins. From
the arborescent venous display upon the surface of the
diaphragm ascend six branches of considerable size ;
these however conjoin afterwards and make but two on
each side, which enter the trunk as it perforates the
tendinous substance.

The Common Iliac Veins

Are formed under the sacro-iliac symphysis by the
union of the external and internal iliacs. Their course,
which is veiy short, is obliquely forward under the last
vertebra of the loins, where they unite and constitute
the main trunk. They receive however — 1. A consi-
derable vein resulting from the union of small branches
coming from the psoas and iliacus. 2. The circumflex
vein of the ileum, from ramifying with its artery. 3.

368 The Internal &> External Iliac Veins.

At their junction, the middle sacral vein, an azygos
vessel of small size, corresponding to the artery bearing
the same name.

The Internal Iliac Vein :

- Is extremely short — in fact it is nothing more thaii
the cbmmon root of the two venous trunks by which it
is said to be formed, viz. the ischiatic and lateral sacral
veins. Its situation is the entrance of the pelvis, a
little outwardly to the sacro-iliac symphysis.

The ischiatic vein, situated upon the side of the
pelvic cavity, midway between the external iliac and
lateral sacral veins, consists of a short but bulky trunk,
and of a collection of large branches uniting to fonn
it at the upper opening of the great sacro-sciatic notch.
These branches may be distinguished into an internal
and an external set. I'he internal comprise veins com-
ing from the bladder, anus, perineum, and, in the male,
from the bulb and prostrates — in the female, from the
vulva and corpora cavernosa vaginee. The external
consist of veins coming principally from the gluteal and
obturator muscles.

The lateral sacral vein originally comes from
the tail, being formed there by two or three slender
coccygeal veins ; it runs forward along the side of the
sacrum, receiving other veins in its course, viz. 1 . Peri-
neal veins, a collection of small branches coming from
the back of the thigh, gluteal muscles, perineum, and
anus. 2. Sacrospinal branches, small veins issuing from
the spinal canal, through the internal sacral foramina/*

The Exter,nal Iliac Vein ;
Is found running along the inner and upper side -of

Vlie Femoral \'fiii.

369

the external iliac artery, taking-, indeed, all the way
precisely the same course as the artery. It extends
from the bifurcation of the posterior vena cava to the
place where it leaves, in company with the artery, the
brim of the pelvis, the vein after that becoming femo-
ral. As it departs from the cavity of the belly, this
vessel receives the

Inguinal vein, one of rather laree size comino;
from the groin, which owes its formation to a consider-
able branch emerging from the muscles of the thigh ;
and a superficial or cutaneous abdominal vein, which
runs in a serpentine manner along the abdomen, after
taking its rise as far forward as the cartilages of the
ribs, where its branches form communications with the
cutaneous veins of the thorax : it is a very conspi-
cuous vessel in milch cows, and is vulgarly pointed
out as the milk vein.

The Femoral Vein

Is the continuation of the iliac trunk below the brim
of the pelvis ; and the main channel into which the
deep-seated veins of the hind extremity pour their
blood. 1 shall commence my description of the veins
of the hind extremity from below, having already pro-
ceeded so with those of the fore extremity ; but it will
not be necessary for us to descend so low as the foot,
for the plantar veins are similar both behind and be-
fore : we may begin therefore at the leg.

The large metatarsal vein having ascended
about half-way up the cannon, by the side of the flexor
tendons, leaves them and takes an oblique course over
the bone to reach the anterior and inner part of the
hock, where it sends down an anastomotic branch un-

part nr. 2 a

370

The Femoral Vein.

der the tendon of the flexor metatarsi, from which an-
astomosis with the small metatarsal vein, and from the
accession of a branch coming from the hock, results the
i^NTEEioR TIBIAL VEIN or veins, for there are
commonly two veins accompanying the anterior tibial
artery. They run between the tibia and fibula to the
inferior and posterior part of the os femoris, and there
are joined by the posterior tibial vein, and all three
unite to form the femoral.

The posterior tibial vein is a continuation of
the small metatarsal vein, which latter corresponds in
comparative size and course to the small metacarpal
vein. It runs in company with the posterior tibial ar-» ^
tery, receiving various muscular branches in its course
and also the medullary vein of the tibia.

The femoral vein is one of large size. It begins
at the place of union of the two last-described vessels,. ;
runs behind the femoral artery, and ends in the exter- ,
nal iliac vein. It receives various large muscular veins,
corresponding to the principal branches of the arterial k
trunk, as well as veins from the stifle-joint, and the^:,:;
medullary vein of the os femoris. Also, about two^j^
thirds of its length upward, it is joined by the saphena u

The vena saphena major, the principal superfi^r'r
cial vein of the hind extremity, takes its rise, at the
inner and fore part of the hock, from the large meta^ 3
tarsal vein, where a branch from this trunk ascends
obliquely round the inner side of the joint to join thsoo
vena saphena minor. It then makes an oblique ascent.
up the middle part of the thigh, covered only by the,-
skin, and higher up plunges inward among the mua.^-5o.
cles to join the femoral trunk. At the hock, -it hfts.ftns

The Vena Porta. 37

remarkable anastomosis with the anterior tibial vein,
thus establishing a communication between the deep-
seated and superficial veins : it also receives many cu-
taneous and muscular branches in its course ; but these
are too variable in their number and distribution to
come very usefully into any general description.

The vena saphena minor springs from the small
metatarsal vein. It runs directly up the back of the
hock, over the root of the os calcis, and pursues its
course upward along the front of the gastrocnemii, and
ultimately joins the femoral vein. It anostomoses with
the greater saphena, and receives in its course both cii-'
taneous and muscular branches.

The Vena Porta.

The veins of the chylo-poietic organs have a pecu-
liar and distinct arrangement from those of the body
in general, and on this account a separate description
is commonly given of them. They receive blood, as
we have already seen, in a similar manner to other
parts, but they return their blood into a channel which
conveys it all through the liver, instead of conducting
it immediately into the vena cava posterior ; this chan-
nel is the vena portae, a vessel principally formed by
the union of the splenic and mesenteric veins, though
it is contributed to also by veins coming both from the
stomach and pancreas.

The splenic vein, in company with its artery,
occupies the fissure of the spleen, makes a circuit in a
flexuous manner towards the right side, receiving- in its
way branches from the stomach, omentum, and pan-
creas, besides all the veins of the spleen, and at length
ends in the vena portae.

2 B 2

372

The Vena Porta.

The mesenteric veins, anterior and posterior,
bear much correspondence to their arteries. The ante-
rior one is of large size, being constituted of those
numerous ramifications which are distributed over the
small intestines together with the arteries ; it also re-
ceives branches from the coecum and coecum caput coli,
some few from the stomach, and some from the pan-
creas. The posterior mesenteric runs obliquely forward,
after having received branches correspondent to those
of its fellow artery.

The vena porta, at its origin, is concealed by the
pancreas, immediately above which its formation taki^s
place. From this, it runs under the beginning of the
duodenum, on the right of the hepatic duct and artery,
to the concave part of the liver. About opposite to
the centre of the right lobe, the vein splits into two
divisions : the right immediately enters the substance
of that lobe ; the left is continued forward with the
hepatic artery, and, as that vessel does, bifurcates to
supply the left and middle lobes. ,

LECTURE LXXlll.

in

Distribution of the Absorbents.

HAVE already spoken in general terms of the struc-
ture and physiology of these vessels, and given an a(^-
count of their diseases ; it only remains for me, there-
fore, to point out their distribution. Prior to corn-
mencing this inquiry however, I shall make a few ob-
servations on their ramification, and point out the me-
thods usually adopted to discover them. ^
The absorbents in general from every part of the body
become ultimately united into two main trunks, by which
the absorbed fluids are poured into the large veins in the
vicinity of the heart. Generally speaking, they ac-
company the veins ; but they are comparatively minute
to those vessels, vastly more numerous and valvular,
still less constant in their calibre and particular distri-
bution, and, lastly, form more frequent anastomoses and
tortuosities in their course. Furthermore, they perfo-
rate or end in and take fresh origin from lymphatic
glands in their way ; though some terminate in the con- \
tiguous venous trunks : some, indeed, even retrogade
for a certain distance ; while others split into two or
more branches which re-unite farther on and form once
more a single tube.

374 Distribution of the Absorbents.

The lymphatic glands are lodged in various unex-
posed places in the body, enveloped in loose cellular
and adipose tissue, which renders them moveable to a
certain extent in accommodation to the motions of the
parts to which they are attached. We find these glands,
commonly in groups or clusters, sometimes solitary,
under the tongue, in the throat, along the neck, in the
axillae, about the roots of the bronchioe, within the
mediastinum, at the roots of the mesenteric vessels,
within the pelvis, and in the groins.

The superficial and deep-seated lymphatics communi-
cate frequently with one another, and both send off
anastomotic branches to whatever solitary absorbents
there may be running in the vicinity; but the glands
themselves are mutually linked together by many rami-
fications which run from one to another, and form therte-
by a continued series of communications.
■^'' The following are the best methods of demonstrating
ihe absorbents *. In an animal opened alive, some
hours after it has been fed, the lacteals are seen turgid
with chyle ; they may also be made visible by throwing
colored thin fluids into the intestines ; or, by making
ligatures on the trunk of the anterior mesenteric artery,
which must necessarily include the trunk of the absorb-
ents. " An eye accustomed, readily distinguishes
lacteals upon the intestines from arteries and veins,
even when they are collapsed and empty : punctures
may be made with a lancet, and the vessels injected
with quicksilver by means of a tube formed expressly
for that purpose. I have sometimes injected lacteals
from punctures made by the sides of veins, where I

* These methods are drawn from the accurate researches ^'of
Mr. Cruikshank.

Distribution of the Absorbents. 375

knew they must be, though they were then invisible to
the naked eye."

Upon the hver and lungs lymphatics are frequently
visible, and may be injected by py.nicturing one of the
small branches ; but the valves almost always make the
injecting of them from the trunk to the branches im-
practicable. Pressure in the course of the absorbent
circulation will commonly force from the extreme
branches into the trunks some little reddish or brownish
fluid, making the latter visible, which may then be
punctured and injected. — Wateiy fluids throvk^n into the
arteries, veins, or ducts of glands, very commonly g^t
into the absorbents and render them visible. — One of
the best methods is to previously inject the arteries and
veins of the part, and afterwards macerate it for some
days ; putrefaction then takes place, air is generated
in the cellular membrane, whence it gets into the
orifices of the lymphatics, and uniformly fills their
branches. — The best subject for these injections is one
^whose limbs are without fat and are dropsical, but not
too much so.

" In parts where glands are to be found, it is only ne-
cessary to puncture the gland and introduce a tube
filled with quicksilver, or push the pipe into its sub-
stance without any previous puncture. The mercury
thus fills the cells of the gland, and from these the lym-
phatics. The thoracic duct itself is most successfully
injected in the same way, that is, either from glands up-
dn the mesentery, upon the bodies of the lumbar verte-
bree, or those upon the inside of Poupart's hgament." —
When vessels are injected, and very much resemble
lymphatics, the best method of determining whether
they are or are not lymphatics, is to trace them to the

376 The Thoracic Duct.

nearest l5^mphatic glands : if they terminate in them
in the usual manner, they are lymphatics/'

No English veterinarian, to my knowledge, has up
to the present day -been at the pains to demonstrate
practically the particular distribution of the absorbing
vessels of the horse ; we have hitherto travelled onward
analogically, and so, I have a notion, should we conti-
nue to do, had not our French professional contempo-
raries furnished us, as well as themselves, by their
praise-worthy exertions in the cause of science, with
materials to fill up this lamentable hiatus in veterinary
anatomy: Professor Girard, whose Traite d'Anato-
mie Veterinare'' does no less credit to the talent and in-
dustry of its author than honor to the veterinary school
over which he presides, has presented us with an article
on the ramification of the lymphatics which I shall
translate, and take the liberty to transcribe into this
lecture.

Ibi The Thoracic Duct. . . ... ^ . ou

The largest, longest, and most remarkable of tJi^
lymphatic vessels, in which terminate the majority of
the lymphatics of the body, is situated within the tho-
rax, on the right side of the dorsal vertebrae, between
the aorta and the vena azygos ; it receives the lympha-
tics from the posterior extremities, pelvis, parietes and
viscera of the abdomen, head, neck, withers, and left
anterior extremity.

" It takes its origin under the loins in a dilatation or
sinus, very variable in its form and dimensions, situated
at the root of the great mesenteric artery, and named
the receptaciihimch7/li ; it directs its course forward, en-
ters the thoracic cavity by the aortic perforation through

The Receptaculum Chyii. 3^7T

the diaphmt^m, extends along the bodies of the dorsal
vertebrge until it arrives opposite to the base of the
heart, where it curves downwurd to cross over to the
left side, in its way to the anterior opening of the thorax,
and, as it leaves the spine for this purpose, runs ob-»
Uquely over the trachea and esophagus ; having reached
the left side, it stretches forward to the beginning of the
anterior vena cava, and terminates, against the middle
of the anterior border of the left first rib, in the base of
the left axillary vein : not infrequently, it ends in th«
right axillary ; in some instances, even, in the beginmag
of the anterior cava. At its termination it dilates and
forms a sinus, whose mouth, opening into the vein, is
guarded by a broad valve so disposed as to prevent any
reflux of blood into the duct * ; it has also a ligamen*.
tons band around it at this part which confines it to the
vein receiving its contents.

" This canal shows but little uniformity in its calibre;
in some places it is strait, in others varicose : it is
not uncommon to find it detaching one and even several
branches in its course, large or small, which either re-
main separate, or else after running a certain distance
rejoin the main channel.

" The Receptaculum Chyli.

■ "This reservoir, (also named ' la citerne lombaire,')
forms the point of general confluence of all the lympha-
tics of the posterior limbs and abdomen, and that from
which originates the thoracic duct : it is maintained by
the aorta on one side, the vena cava posterior on the

* " Notwithstanding this valve, blood often gains admission into
the canal ; this is observable in all cases of violent death, or in
which struggles and convulsions attend expiration,"

378 Lymphatics of the Posterior Extremities.

other, and is formed by the union of five or six large
lymphatics, of which two or three come from the en-
trance of the pelvis, two or three others from the me-
sentery, a single one from the environs of the stomach
and liver,"

The Professor here makes a classification of all the
Ijrmphatics of the body into those that proceed to the
abdominal and those that run to the thoracic portion of
the duct.

1. Lymphatics discharging their Contents
INTO THE Abdominal Portion of the Tho-
racic Duct.

"1. Lymphatics of the Posterior Extremities.

"These are distinguishable into the superficial and
deep-seated. The first originate particularly from the
skin and subcutaneous cellular tissue. They form divers
ramifications which accompany the superficial veins j of
which the most remarkable attend the vena saphena ma-
jor, frequently anastomosing with one another, atid
forming altogether an anastomotic network. All thes6
lymphatics run to the subcutaneous inguinal glands,
which are lodged upon the superior and anterior part of
the thigh . }

" The deep-seated lymphatics take their rise from the
foot, ascend along with the plantar veins, continue up-
ward among the muscles in company with the deep-
seated veins, corresponding in their principal divisions
to those vessels, and proceed to the inguinal glands.

*' All the lymphatics of the posterior limbs assemble
at these glands, and here form a plexus, from which
several large branches depart and traverse the iliac
glands, clinging to the sides of the iliac vessels, and

Lymphatics of the Pelvis. 379

discharge their contents into the pelvic branch contri-
buting to the receptaculum chyli.

" 2. Lymphatics of the Pelvis.
'* The vessels coming from this cavity run in part to
the inguinal glands and in part to the internal pelvic
glands. The superficial lymphatics about the pubes
and the outlet of the pelvis run and join those of the
extremity ; those of the perineum and anus enter the
cavity, and are accompanied by those coming from the
croup and tail, both proceeding to the glands within the
interior of the pelvis. All the deep-seated lymphatics
accompany the veins, make for the pelvic glands, form
unions with the others, and run and empty themselves
into the main pelvic branch, wherein their lymph mixes
with that coming fnom the inguinal glands.

The lymphatics of the urinary and genital organs,
included in the pelvic cavity, also traverse the glands
lodged therein, and unite with those of the parietes of
the pelvis. Those of the scrotum enter the inguinal
glands, as also do those belonging to the sheath and
penis. The ramifications derived from the testicle and
spermatic cord take the course of the veins, and pene-
trate one or two of the lumbar glands lodged at the en-
trance of the pelvis. The lymphatics of the mammae,
which are also divisible into superficial and deep-seated,
run to the inguinal glands, and anastomose with the
superficial set belonging to the inferior parietes of the
abdomen ; but, before they reach these last glands they
pervade those of the mammae.

" 3. Lymphatics of the Parietes of the Abdomen.
" These vessels, in general but little developed, for

380 Absorbents of the MescHfen/.

the most part run to the inguinal glands. The super-
licial set of the lower parietes accompany the cutaneoas
(inguinal) vein, anastomovse with the lymphatics of the
scrotum and mannna?, and traverse the glands in the
groin : some of them direct their course forward along
with the cutaneous (external thoracic) vein of the thorax,
unite with the superficial lymphatics of that part, and
proceed to the axillary glands. The deep-seated vessels
of the belly run in company with the epigastric vein,
and go to the inguinal glands, or else they accompany
the pectoral vein, and pervade the glands in front of the
thorax.

*' The superficial or subcutaneous lymphatics of the
loins join either those of the croup or those of the
flanks : the deep-seated, which spring from the perito-
neum, muscles, or spinal canal, perforate one of the
internal lumbar glands, and pass onward to terminate
in the main pelvic branch.

'* Among the lymphatics of the abdominal surface of
the diaphragm, those issuing from the peritoneum and
muscular texture make almost all for the main hepatic
branch ; some others take the course of the phrenic
veins and form a union with those of the thoracic side
oi'. the muscle. "

"4. Absorbents of the Mesentery . t^??
i£^« THE mesenteric branches, ordinarily two or three
in number, the most considerable of which is constantly
united to the great mesenteric artery, receive all the
vessels continued from the mesenteric glands, as well as
those coming from the mesentery and intestines. '"^^
''The mesenteric absorbents, extremely num'er6ii^t'
arc sustained between the layers of the mesentery

'LymphaLics of the Liver, Sloinacli, 6)C. 381

where they form a vascular network ; many of them is-
sue from the exhalent surface of the mesentery and in-
testinal tube j others take their rise from the interior of
the intestine, from which they imbibe chyle. All these
vessels converge towards the lymphatic reservoir, cling-
ing in their passage around the mesenteric veins ;
some however taking a solitary course at a greater or
less distance from any bloodvessel : having arrived at
tlie root of the mesentery, they pass through one or
two, sometimes three, of the mesenteric glands, and
afterwards join the principal lumbar lymphatics. The
absorbents of the coecum and coecum caput coli run to
the glands set at intervals along the intestinal tube,
whence they proceed to the receptaculum chyli. (jioi

^jLymphatics of the Liver, Stomach, Spleen, and

Omentum.

" The hepatic trunk comprises the lymphatics issuing
from the liver, stomach, spleen, and omentum : this
branch of the receptaculum chyli not uncommonly con-
sists of two divisions, and receives, in addition to the
above-mentioned vessels, many ramifications from the
crura of the diaphragm.

" The lymphatics of the liver, extremely numerous^
are distinguishable into a superficial and a deep-seated
set. The first arise more particularly from the exhalent
surface of the organ, creep along upon its peritoneal
capsule, and there form a plexus of close and intricate
network. Those from the anterior surface make one or
two large branches which perforate the diaphragm, en-
ter the thoracic cavity, unite with the lymphatics from
the coTdiforai tendon, and proceed to the fore part of

382 Lympkalics of the Liver, Stomach, ^,c.

the thoracic duct ; whilst those of the posterior surface
enter the glands placed around the great fissure, where
they unite with the deep-seated set.

The deep-seated hepatic spring from the parenchyma
of the gland, cling around the divisions of the hepatic
artery and hepatic veins, issue from the interior of the
viscus by the great fissure, run to the glands there, and
afterwards proceed with the superficial to the main
hepatic trunk.

" 2'he h/mphatics of the stomach, of which the super-
ficial come from the external surface, the deep-seated
from its cavity, follow the veins, and are distinguisha-
ble into a superior and an inferior set. The former
take the direction of the lesser curvature, perforate the
glands thereabouts, and go to join the absorbents of
the liver ; the latter run over the greater curvature,
enter the glands arranged along the fissure of the
spleen, form communications with the lymphatics of
that viscus and those of the omentum, and depart to
contribute to the hepatic trunk.

" As to the lymphatics of the spleen, the superficial,
like those of the liver, come from the periphery of the(>9^
organ and enter into a thick and complicated network ;
the deep-seated issue from the interior, and contract
with the former numerous anastomoses. Alono- the
fissure of the spleen these vessels become united, form
large branches which follow the course of the splenic
veins, and anastomose with the lymphatics of the great
curvature of the stomach ; both sets then run to the
great fissure of the liver, and there terminate in the
hepatic trunk.

" The lymphatics of the omentum accompany the ve-

Lymphatics of the Parietes of the Thorax. 383

nous ramifications, and either join those of the great
curvature of the stomach, or the superficial absorbents
coming from the ccecum caput coli ; those around the
pylorus anastomose w ith the pancreatic, and accompany
them to the hepatic trunk.

*' The lymphatics of' the pancreas also run with the
divisions of its veins, and join either those of the liver
or those of the spleen ; some proceed directly to the
common hepatic trunk.

" Besides these three portions or lymphatic trunks
which constitute the receptaculum chyli, the abdominal
portion of the thoracic duct also receives the lymphatics
of the kidneys and renal capsules. These vessels, dis-
tinguished into superficial and deep-seated, perforate
the glands placed, internally, next to the parts from
which they spring, and empty themselves into the supe-
rior side of the thoracic duct.

II. Ramifications terminating in the Tho-
racic Portion of the Main Common Duct.

" This, the terminating portion of the thoracic duct,
receives the lymphatics transmitted from the internal
dorsal, bronchial, and cardiac glands, and those either
from the left axillary glands, or from the sublingual
and guttural glands. In this numerous series we find
the lymphatics of the parietes and viscera of the
thorax, of the head, neck, and left and anterior extre-
mity.

1. Lymphatics of the Parietes of the Thorax.

"The super-ficial absorbents of the chest take their
rise either from the surface of the skin or else from
the subcutaneous muscles ; they form several large

384 Lyinphatks of the Thoracic Viscera.

branches which accompany the thoracic cutaneous vein,
unite with the superficial lymphatics coming from the
anterior parietes of the abdomen, and proceed to the
axillary glands.

The deep-seated set take divers directions and pass
through different sets of glands. The pectoral, which
anastomose with ramifications from the abdomen, fol-
low the pectoral vein, and reach one or two glands at
the entrance of the chest. The intercostal spring from
the pleura and intercostal muscles, accompany the in-
tercostal veins, pervade the internal dorsal glands, and
terminate by several branches in the thoracic duct.
The lymphatics of the fleshy part of the diaphragm unite,
some with the posterior intercostal, others with the
pectoral ; those coming from the crura run to the dorsal
glands, where they anastomose with the intercostal ;
those from the cordiform tendon anastomose with the
deep hepatic, run forward between the layers of medias-
tinum, nearly to the heart, and enter the cardiac glands.

2. Lymphatics of the Thoracic Viscera. ,

"The absorbents of the different organs contained
within the thorax, traverse one or several of the bron-
chial or cardiac glands, and afterwards form divers
branches which end in the thoracic duct. The pulmo-
nary lymphatics, very numerous, are distinguished into
superficial and deep-seated. The first take their rise
from the surface of the lungs, creep along under their
enveloping membrane, and make for one or more of the
bronchial glands. The deep set, which originate from
the air-cells and from the areolae of the parenchymatous
tissue, follow the divisions of the pulmonary veins,
run to the root of the bronchiae, there unite with the

1

J

Lymphatk^ of the Head. ■ ' 385

^superficial, and perforate one or two of the ))ronchial
inlands.

»n>' The cardiac lymphatics derive their origin, either
from the surfaces (both exterior and interior) of the
heart, or from the muscular substance of the organ ;
they mount upon the curvature of the posterior aorta,
and disappear in the cardiac glands.
If ** The lymphatics of the superior part of the medi-
astinum and of the esophagus join, some the intercos-
tal, the others the bronchial ; those coming from the
anterior part of this membranous partition, from the
thymus, trachea, and esophagus, unite, either with the
pectoral, or else with the cardiac and anterior inter-
costal.

"3. Li/mphatics of the Head.

-The lymphatics of the head form two planes, a
superficial and a deep one. The superficial pursue the
course of the cutaneous veins, and run in part into the
sublingual, in part into the guttural glands. The deep
vessels, which come from the nostrils, fauces, palate,
Stc. also run to the subHngual and guttural glands, in
which they unite with the superficial. From these two
groups of glands, through which pass the lymphatics
of the head, depart several large branches, two or three
of which descend upon the anterior face of the tra-
chea ; others follow the passage of the deep and sub-
cutaneous veins, unite with those of the neck, and
descend to the front of the chest. Almost ail these
vessels terminate in the thoracic duct ; some few
alpne on the rigiit side ending in the right axillary
trunk.

EifAfttf in. 2 c

386

" 4. Lymphatics ofthe Left Fore Extremity.

" Th e lymphatics of this member present the same
disposition as those of the posterior limbs, and are
divided into superficial and deep-seated. The former,
consisting of divers ramifications, accompany the su-
perficial veins ; the more considerable of them forming
a plexus which accompanies the cutaneous (superficial
brachial) vein of the limb. The deep vessels originate
from the foot, muscles, and bones, pursue the divisions
of the deep veins, and plunge into the axillary glands,
wherein they unite with the superficial, and whence
they extend to the thoracic duct.

" The Right Terminating Trunk of the Lymphatics.

"This very short lymphatic canal is obliquely situ-
ated at the entrance of the thorax, upon the transverse
process of the last vertebra of the neck, extending in a
direction from above downward tind from without in-
ward, and terminating most commonly in the right
axillary vein ; though in some instances it joins the
thoracic duct, or else ends close by the side of it. —
This lesser trunk is formed by the lymphatics coming
from the right axillaiy glands, and some from the right
lung, and right side of the neck and trachea."

LECTURE LXXIV.

-m-^ ^-^^ ^s/v ^■r^

On JPerer.

IjEST the title of this lecture may startle the dis-
ciples of our present school of veterinary medicine I
beg to qualify it in limine by premising, that it is my
intention herein fully and deliberately to investigate
the subject with a view of coming to safe practical con-
clusions on two long-standing and still-pending ques-
tions of very great interest and importance to us, viz.
Are horses liable to fever 1 And, if they are, what is
the nature or kind of fever to which they are subject ?

These are two very plain questions, and one would
think, after between 30 or 40 years' experience, ques-
tions that might be promptly, plainly, and satisfactorily
answered ; so far however are the accounts, both writ-
ten and oral, from being conclusive that I know of no
subject about which there is more wavering, nay, dis-
cordance and discrepancy of opinion, than that of fever.
Ancient veterinary works yield nothing of interest on
the subject ; most of the old English writers on far-
riery, as well as the French, give descriptions of fe-
vers of various kinds ; Messrs. Feron, White, and
Blaine treat of fevers ; Professor Peall, though his

2 c 2

388 On Fever.

work includes the principal diseases to which horses
are hable, devotes no part of it to fever; Professor
Coleman, when I was a pupil, appropriated no lecture
in the whole course to the subject of fever. In order
that we may set about this investigation with minds in
some degree prepared to meet the subject, comprehend
its various bearings and relations, and ultimately draw
up judicious and safe answers to the foregoing ques-
tions, let us first take a cursory view of what the most
eminent human nosologists have defined fever to be.

Our word fever appears to have come to us from the
French word Jievre, for the two are very like, and the
latter is derived from the latin noun Jebris, which is
related to the verb ferveo, signifying / am hoi : an
origin that is perfectly accordant with the symptom
most likely to attract the attention, namely, the in-
creased warmth perceptible in the skin. Here we per-
ceive an analogy between the words fever and inflam-
mation ; the latter coming from the Latin noun Jiaiuma,
flame, and that again from the Greek verb ^Xeyw,
which signifies / burn, as if the one was a local heat
or burning, the other a general heat ; and this, in point
of fact, we shall find to be the case. We must not
run away with tlie idea however, that the essence of
fever consists in increased temperature of body ; for
this is an indication that has frequently been known to
be absent during the whole course of the disease, and
when present is only to be regarded as one of its pro-
minent or characteristic symptoms. But, let us see
what the most eminent physicians have set down as the
signs or symptoms collectively constituting fever ; for
it has been correctly observed by modern patholo-
gists, that, so far from any one of them being essential

On Fever. 389

to its existence, each has been known to be absent, and
all occasionally present, whei'e there has been no fever.

BoERHAAVE, the late distinguished professor of me-
dicine at Leyden, says, in his Aphorisms — " In every
fever, arising from internal causes, there is always a
shivering, a quick pulse, and heat, varying in degree at
different times of the fever." And further on — " These
symptoms indeed are present in eveiy fever, but the
QUICK PULSE alone is present through its whole course,
from the beginning to the end, and by that only the
physician judges of the existence of fever."

Dr. CuLLEN, the late learned professor of medicine
at Edinburgh, in his Si/stema Nosologicum, has ar-
ranged five orders under his class pyrexia, or febrile
diseases, viz. I. Febres, simple idiopathic fevers. II.
Phlegmasia, inflammations attended with fever. III.
Exanthemata, eruptive fevers. IV. Hamorrhagict, he-
morrhages attended with fever. V. Projluvice, fluxes
attended with fever. His general characterization of
pyrexiae is this — " Post horrorem, pulsus frequens,
calor major, plures functiones laesa?, viribus presertim
artuum imniinutis*." To his first order, comprising
fevers properly so called, he gives this definition —
" Prsegressis languore, lassitudine, et aliis debilitatis
sio-nis, pyrexia, sine morbo locali primariof."

Dr. FoRDYCE, in his " General Doctrine of Fevers,"
presents us with a description of an ague, a febiis inter-
mittens of Dr. CuLLEN, as a specimen of pure fever,

• " After shivering (or a sense of coldness) a quick pulse, in-
creased heat, disturbance of several functions, prostration of
strength."

■\ '* Pyrexia, without any primary local disease, following larx?
o;uor, lassitude., and other signs of debility."

390

On Fever.

of which he considers the others (as indeed did Dr.
Cull EN before him) as variations. Now, an ague is
a periodical fever characterized by three stages, viz. a
cold, hot, and sweating stage or crisis : the symptoms
I subjoin in a note in order that we may have this as-
sumed prototype of human fever before us*.

By these eminent physicians continued fevers were
regarded as variations of the intermittent ; indeed, as I

* Fever generally commences with " languor, weariness, weak-
ness, diminished sensibility, cold and trembling, pain in the back.
Rigor, horror, horripilatio, (the technical terms for shivering) suc-
ceeds ; the skin becomes pale and dry; the tongue, dry and foul,
with thirst; transparent urine; costiveness; and suppression of
other secretions; pain,in the limbs, joints, and forehead — delirium.
Anxiety follows ; oppression and swelling about the praecordia ;
frequency of pulse ; quick and laborious respiration ; thirst, flatu-
lencies, loss of appetite, nausea and vomiting. Unless these, the
symptoms of the first stage, destroy the patient, they are followed
by the second stage or hot ftt, consisting in — Rigor and horror,
heat arising from the praecordia and diffused from thence over
the body irregularly, unequally, and with flushing ; a strong, full,
obstructed pulse ; or a very frequent, small one ; pain in the
head, and joints ; stupor and dilirium ; universal soreness ; red-
ness arising in different parts irregularly ; the urine high-colored,
but perfectly transparent ; sweating in the head and breast, or
over the whole body ; partial secretions. — The symptoms of the
first stage arc gradually relieved. At last — the crisis — the pulse
becomes free ; all the secretory organs are relaxed ; hence the skin
grows soft, and moist, and returns to its natural color; the tongue
likewise is soft and moist; the belly is open; and the urine is
discharged in greater quantity ; if transparent when voided, after
a little time it becomes turbid and opaque, and at last deposits a
copious sediment : the secretions are often greatly increased ■
there arises a copious and universal sweat, or a purging, or a
great flow of m'me."— Elements of the Practice of Medicine, by
Geo. Fordyce, M.D. F.R.S

On Fever.

391

observed before, all febrile diseases were referred to the
paroxysm of this one as the archetype. And this ap-
pears to have been assumed as the standard by which
we are to determine the question of the occurrence of
fever in horses. But, what can be more unpathological
than such a notion as this ? In the human frame even,
fever puts on such various aspects that (as an ingenious
writer remarks) " fancy rather than sound observation"
seems to have led to the above ascription of such affinity
between them ; but, to pretend to make a human inter-
mittent the prototype of fever in horses, is surely stretch-
ing analogy in medicine to an unwarrantable extent !
If we can prove that fever in horses is essentially/ the
same in its nature, so far as we can judge from its prin-
cipal symptoms, its general causes, its common pro-
gress and termination, we do all in my mind that is re-
quired to establish its existence ; but, we can do more,
its symptoms individually will even admit of a compa-
rison with those of human fever, and to me too plainly
indicate the same derangement of the system at largo
to be reasonably ascribed to any other origin.

There is a fever to w hich man is more subject than to
any other, commonly called injiammatory fever, tech-
nically named by Dr. Cullen, sijnocha, and thus de-
fined by him — Calor plurimum auctus ; pulsus fre-
quens, v^lidus, et durus ; urina rubra ; sensorii func-
tiones parum turbatae *." In fact, this is a fever cha-
racterized by a greater development of the hot stage of
the intermittent ; for the cold stage is here frequently
absent altogether, and when present is always consider-
ably less marked ; and the hot fit is not followed by any

* " Heat, much increased ; pulse, frequent,, strong, and hard ;
urine, high-colored; sensorial functions, but little disturbed."

392^ On Fever.

regular sweating stage. During its progress, reniis--.
sions may be evident or not ; and the inflammatory ex-^
citement may continue all through, or the latter stages
may be marked by symptoms of weakness and nervous-
ness, which belong to a fever of debility denominated
ti/phus.

The numerous forms of human fever distinguish them-
selves in practice into two general classes : those aris-
ing from causes operating on the system at large, or that
originate without any apparent cause, denominated
primanj or idiopathic fevers ; and those arising from in-^
flammation or any other local affection of a particular
organ, hence named secondary or symptomatic fevers.

With these observations before us on the definition,
symptoms, and classification of human fever in general,
I shall, prior to submitting opinions practice has long
established in my mind, make a few extracts from the
most popular veterinary authorities on the subject of
fever in horses. jiouuiib dun .ant

lis ;s|mt«^ld n3ftv# jufJ

Gibson makes three classes of fevers: simple continued fevers,
compound fevers, and epidemic fevers. The first, he say^, " appears
from the writings of Seignior Russini, Solleysel, and other
foreign authors, to be very frequent in hotter climates; and I have
frequently met with it among our own horses, in the summer
especially, when the weather has been hot and sultry, and the air
much rarified." He ascribes their origin to hot and bciraulating
diet, and certain atmospherical temperaments, " for I have known/'
lie adds, several horses in this fever, at the same time, and in
different places, where no other visible cause could be assigned for
it." The symptoms he gives, are — restlessness, beating at the
flanks, eyes red and inflamed, tongue parched and dry. The horse
looks lively instead of being dull^ and is " very attentive to any
noise," the reverse of which is the case in complicated fevers. Loss
of appetite. " His ears and feet generally feel cold, or alternately
hot and cold."— Other parts commonly hotter than ordinary. Urine

On fevei-: 393

high-colored. Thirst. — "Complicated or compound fevers are de-
nominated malignant, putrid, or' pestilential." — "Malignant fevers
are not nncommon in horses, though few practitioners, for want of
a competent knowledge in such things, have been able to distin-
guish them from severe colds, or other diseases attended with fever-
ish symptoms."

Bracken, Gibson's contemporary, though he does not questioit
— indeed he acknowledges the occurrence of the other fevers men-
tioned by Gibson, only however gives a detailed account of one
which he calls symptomatic fever, though it is evident, that, accord-
ing to the views entertained by the former writer, it is also idiopa-
thic ; for he says that very hot weather, suppressed perspiration,
&c. may bring it pn. The signs of fever, according to this author^
are " violent heat, and fulness of the vessels, a beating of the heart
and flanks much quicker than ordinary; a dryness in the mouth
with roughness of the tongue ; continual watchfulness and restless-
ness." He concludes witli saying, — " I tliink it needless to enu-
merate all the different kinds of fevers, such as putrid, pestilential^
hectic, intermitting, and the like."

Bartlet, whose compendious and pithy work contains no mote
concerning fever than the treatment, observes that " warm cloth-
ing, with dilution, and abstinence from diet, will go great lengths ;
but when bleeding and gentle evacuants are joined to these, the end
is generally accomplished in a few days.''

That keen and clever but censorious writer, Taplin, commences
his description of fever thus truly and remarkably. " The observa-
tions and reflections that first induced me to perceive the absolute
necessity of some reformation in the practice of farriery, never
influenced me more in a conviction of that want than did a tho-
rough investigation of the subject before us." He divides " febrile
disquietudes simply into two kinds, the symptomatic and the in-
flammatory."— " The pathognomonic or certain signs are, a uni-
versal heat and disordered pulse, a palpable disquietude and tnieasi-
ness ; shifting from place to place; the horse labors under difficult
respiration, his mouth is very dry, his tongue is parched and hot,
he declines food, but receives water : sometimes seizes his hay with
seeming eagerness, then drops it in disappointment ; the body is
generally costive, and in the early state of the disease there is a
proportional obstruction of urine."

394

On Fever.

Ferok says, " Horses are subject to one species of fever only- —
But when a horse is taken with a fever, it is much more dangerou$
than when thai malady visits 7nan. — Fever in animals is seldom a
primary disease, being always associated with and originating from
a variety of diseases, such as catarrh, strangles, pneumonia, frac-
tures, &c."

White says, "The fevers of horses bear very little analogy to
those of the human body, and require a different treatment. — lean
distinguish only two kinds of fever, the one idiopathic or simple ; the
other, symptomatic. The simple fever does not occur so frequently
as the symptomatic, nor is it by any means so formidable in its ap-
pearance.— The following arc the symptoms of simple fever —
shivering, succeeded by loss of appetite, dejected appearance,
quick pulse, hot mouth, and some degree of debility : the horse is
generally costive and voids his urine with difficulty. The disease
is often accompanied with quickness of breathing, and in a few
cases, with pain in the bowels, or symptoms of colic. — When a pain
is symptomatic it is not perceived by shivering, nor is it so sudden in
its attack as simple fever. When the symptoms mentioned are
joined by difficulty of breathing and quick working of the flanks,
with coldness of the legs and ears, we may conclude that an in-
flammation of the lungs is the cause of fever."

Mr. BtAiNE brings up this cursory exposition of the opinions of
our latest veterinary writers who have treated on fever, and ob-
serves, " that fever in the horse does very seldom exist as a primary
affection; and that it still less frequently remains in an original
idiopathic state without being transferred to some one particular
organ. Mr. B. divides fevers into simple or idiopathic, epidemic or
catarrhal, malignant epidemic or catarrhal, and symptomatic.'' In re-
gard to the first, Mr. B. observes — "Pure fever is certainly a rare
occurrence in the horse ; but I am disposed to think that it is not
so much its extreme rarity which renders its existence disputed, as
that his constitutional tendencies are such as seldom allow general
fever to prevail in him, without a more active and local transla-
tion of the inflammation to some vital organ. — In my own prac-
tice I have certainly met with this (inflammatory) fever.— The
symptoms that present themselves are, first, a shivering fit, in
which the skin is corrugated, and shakes violenllv ; the hair stares,
and the legs, ears, and muzzle, feel intensely cold— To these some

Chi Fever.

395

degree of heat succeeds, and the horse resumes nearly his usual
habits; until the second cold fit occurs, after which the pulse
becomes increased in frequency and fulness. The skin is found
alternately hot and cold, with occasional partial sweatings ; the bow-
els rumble and are flatulent, and general uneasiness without acute
pain is manifested by restlessness and frequent shifting of position .
The inner surface of the eyelids and nostrils is slightly increased in
redness ; thirst is present, and costiveness is also common, but the
respiration is not greatly accelerated." Should this, the first stage
of fever, not prove to be the prelude to any local disease, but re-
main " purely idiopathic, which, though very seldom, does now
and then happen, a series of symptoms supervene, seldom invariably
the same in any two subjects, but with sufficient general characters
to describe them as follows : — The pulse continues to have a corded
feel, but loses still more of its fulness and increases in quickness ;
the skin also becomes moist, the eyes weep and appear red and in-
flamed ; and while the nose secretes a thin acrid fluid, the mouth
is usually hot and dry. The urine at first is gradually secreted in
larger quantities, and becomes of an opaque color. It is not unusual
also for the hind legs to swell, and sometimes likewise serous de-
posits take place about the head, the throat, or along the chest and
belly ; and when these ocoir early in the complaint, I should con-
sider them in this, as in the epidemic catarrh, rather as favor-
able indications ; that is, I have found the irritative fevers of the
horse, so accompanied, more tractable than others without : but I
think I have observed the reverse of this to be the case in the fevers
in horned cattle. — What I have just described may be considered
as constituting the middle and principal stage of this fever, to which,
under favorable circumstances, there succeeds a softer and less
frequent pulse ; the countenance looks more lively ; and although
the muscular weakness rather increases, the irritability lessens ;
the secretions also return to their natural state ; the mouth feels
cool and moist, and the heat of the body becomes lessened, as well
as regular and equable throughout ; slight symptoms of returning
appetite likewise appear : under which circumstances a resolution
of the fever is formed. An unfavorable termination I have never
seen, and consequently I cannot describe the more mortal symp-
toms."

To these accounts, I have considerable satisfaction in having it in

396 On Fever.

my pow6r to subjoin the results of a similar investigation, contained
in the French V^eterinary Journal, in an ingenious article, entitled,
" Existe-t-il, en mcdecine vet'crinaire, des exemples bien constates de ficvres
essent idles V by the lamented son of the present Professor Giraro,
whose talents and professional ardor manifested great promise in
the cultivation and improvement of veterinary science. He winds
up a cursory review of the principal French veterinary writers on
fevers with these conclusions.

" 1st. That SoLLEVSEL, Garsault, Bourgelat (and Dela-
BiERE Blaine), though they admit the existence of essential (idio-
pathic) fevers in domestic animals, leave us to discern, by the man-
ner in which they express themselves, that they do not write from
actual observation, but only conform to the general opinion.

**2(7. That Lafosse and VoLPi (veterinary professor at Milan)
Qo not believe in its existence.

"•■ 3rf. That Vitet describes fevers as they are found in works on
humah medicine, and that he has been followed by Rozter and
others.

"'**4?A. That the later authors who have mentioned fevers, are
allcopists, their readings being merely varied conformably to cer-
tain new doctrines of the day.

" bth. That the observations reported in the ' Instructions Vett-
rimires,' so far from offering any proofs of the existence of fever,
militate in favor of a contrary opinion.

** 6th. That the malignant, petechial, and typhoid fevers, and the
epizootics of the eighteenth century, &c. have been found, on ex-
amination after death, to be attended with marks of violent in-
flammation in different organs, more especially in the digestive
viscera.

" 7ih. Lastly, that we are not warranted, by the observations in
our possession, in considering that fever can exist in domestic ani-
mals independently of organic lesion somewhere ; that the word
fever, whether it be used to denote diseases attended with danger, or
a salutary effort of nature to free the system of some noxious agent,
ought to be interpreted, a group of symptoms which indicate or
represent more or less faithfully an inflammation, (local ?) JRe-
cueil de Medecine Vcter. Cahier de Septembre, 1824."

M. Da MOisEAU has presented us with a case of intermittent
fever in the horse, the only accredited observation of the kind, I

On Fever. 3^

believe, recorded in veterinary medicine, and one of considerable
importance to us here, on which accounts I shall transcribe it.

" On the '2d of December, 1807, about three o'clock in the af-
ternoon, a stallion suddenly manifested inquietude. The pulse was
small, contracted, and intermittent; mouth hot; tongue coated
witli a blackish fur; mucous surfaces saffron-colored; painful ten-
sion of the right hypochondrium ; stiffness about the spine ; re-
spiration short and laborious. This was followed by universal
coldness; he stood all of a heap; the coat lost its gloss and
stared ; the pulse became almost imperceptible, and the eyes
greatly downcast. After three quarters of an hour, the vital ener-
gies appeared revived ; the coat shone, the pulse grew very quick.
(90 ill a minute.) This stage lasted nearly half an hour, and then
he broke out into a profuse sweat ; the pulse was full and soft,
natural in frequency ; the symptoms gradually disappeared ; ap-
petite returned, and vigor and animation. On the 6th inst. at the
same hour, another paroxysm. On the 7th and 8th, intermission.
On the 9th, paroxysm less violent than the two preceding. From
which day the paroxysms became irregular; the ague appeared to
assume the tertian type ; at length, it became quotidian : it left exr
treme weakness behind, and the recovery was not completed
until March. Correspond, de Fromage de Fetigrc. Tom. iv.puge 48."

On this, and two other cases of minor interest, (one of meningo-
gastric fever, the other of mucous fever,) M. Giraru comments
thus. "The observations of M. Damoiseau are incomplete, in-
convincing, and valueless, (sans J'orcc ct sans valeur,) because the
subjects could not be anatomically examined, and because they
appear to have been no more than cases, either simple or com-,
pound, of gastro-enteritis. — And we can much better explain
the intermissions of fever by regarding them as the results of di-
vers phlegmasife, than by considering them as idiopathic, since we
have an inflammatory affection (specific opthalmia,) in which the
intermission is well defined, and which nevertheless is never pre-
ceded and rarely accompanied by febrile commotion." Loc. cit.

Here, then, we have presented to us the observa-
tions and opinions of the principal veterinary writers,
French and Italian as well as English, on the subject

398

On Fever.

of fever : and it constitutes a mass of evidence altogether
that I cannot, injustice to its authors, and in consider-
ation of what I have of my own to advance, pass over
without comment. It is with considerable hesitation
that I join in sentiment with Girard, and with him
have to pass such a sweeping censure as he has done iii
his second corollaiy, that most of these writers, " s'expri-
ment de maniere a laisser entrevoir qu'ils n*en ont jamais
observe eux memes, et qu'ils ne font qu'obeir a I'opi-
nion generale;" but, really, when one comes to criti-
cally examine their accounts, and compare them one
with another, one can hardly refrain from coming to the
conclusion, that their descriptions were originally de-
rived from human medicine, and have been but variously
modified to suit the prevailing doctrines of the day, from
the time of Gibson and Bracken and Bartlet.
It is pretty evident that Gibson, to use the words of
Taplin, "has gone through a system of imaginary
fevers; and regularly transferred the observation and
language of ancient ' authors upon the diseases of the
human species to the constitution of quadrupeds."
Taplin dismissed the complicated or compound — the
imaginary fevers of these authors, and simply consider-
ed them as idiopathic and symptomatic ; he however has
passed by the main question without any practical
remark whatever, and seems totally to have neglected
the study of morbid anatomy. Feron quite staggers
credit when he states that fever is much more dan-
gerous in a horse than in a man. White has pru-
dently abstained from " dabbhng in troubled waters:"
he has not forgotten however to bait his chapter on
fevers with some antimonial powders, which he knew are
so grateful to the palates of his Newmarket readers, for

On Fever.

399

which they ought, in veneration to his memory, out of
common gratitude, erect him a statue in the middle of
the round mile. I am sorry to see so respectable and
experienced and persevering a practitioner as Mr.
Blaine, led away by the accounts to be found in va-
rious old authors of epidemic and malignant fevers, be-
cause the descriptions, unsupported as they are by the
evidence of actual observation and morbid anatomy,
are not of that stamp that deserve implicit reliance,
and because modern practice, so far from confirming,
goes directly to gainsay them. There seems no rea-
son to doubt that epidemic, or rather epizootic and
sporadic diseases have made such ravages as Gibson
and OsMER and several old French authors have re-
ported, but there is great reason to doubt that these
diseases were not idiopathic fevers: the symptoms,
such as are put down to them, are mostly referable to
certain phlegmasiae, and their true seat and origin
would have been discovered in all probability had these
authors been more diligent inquirers after such practical
facts as can alone render such accounts of value to us.

M. GiRARD, who has taken up the subject in a very
proper and praise-worthy manner, and has manifested
considerable penetration in reviewing the accounts of
the French authors, is, it is plain to perceive, a disciple
of M. Broussais, who would place the fons el origo of
fever in the stomach and bowels, and explain the phe-
nomena of intermissions and remissions by asserting the
intermittent character of the local inflammation, which
GiRARD further exemplifies by a reference to the spe-
cific opthalmia. But, we have no more reason, indeed,
in my humble opinion, not near so much to give fever
a habitation in the abdomen as we have to enthrone it

400

On Fever.

in the head, with Dr. Clutterbuck ; for the brain,
rather than the stomach, seems to stand foremost in the
order of organic derangement. But, it would appear
from the full range of observation, that no part of the
body can be said to be insusceptible of inflammation in
human fever, though, at the same time, no organ is
invariably or exclusively affected : nay ! indeed, some
tell us that inflammation is not essential to fever at all
— that it is merely a casual occurrence in fever ! Be
this however as it may, all I wish to contend for is, that
botli idiopathic and symptomatic fevers exhibit the same
form, characters, and species, and require the same
general means of cure ; and that, were it not for the local
affection, it would be difficult or impossible to distin-
guish them. And if there be no apparent or discover-
able difference in these fevers in a man, though we
know that one proceeds from some local malady, while
the source of the other is wholly a mystery to us, are
we not, to reason at least analogically, warranted m
ascribing the presence of an idiopathic fever to a horse,
when the animal shows the same set of symptoms,
without manifesting signs of local inflammation, which
he exhibits after a violent local injury ? However,
it is not my intention to rest the question upon any ne-
gative evidence ; and therefore let us now come fairly
to the point, and see how far we can demonstrate it by
the tests of actual practice.

We will suppose, for the sake of illustration, that a
horse leaves his stable perfectly sound and well, but in
the course of his journey " picks up a nail and that
this nail penetrates the foot deeply, and occasions
poignant pain with excessive lameness : I could scarcely
have selected a more common case than this. Such

On Fever.

401

an accident, as every one knows, is speedily followed
by acceleration of the pulse and respiration, by heat of
skin, loss of appetite, derangement of the secretions
and excretions, and signs of more or less sensorial dis-
turbance. I should like to know by what name I am
to desicvnate this constitutional affection if I am not to
call it J'ever ? And, if I may be allowed to give this
the' appellation of fever, how am 1 to distinguish in
my nomenclature the very same set of symptoms when
they arise without any apparent injury, or rationally
Assignable local phlogosis ? I say rationally assignable
local disease because I know that this last by some
will be called injiammation of the lungs, and for this
sage reason, because the breathing is increased ; but,
was not the breathing increased in the case of the nail in
the foot ? And is it not likewise increased in gripes,
and enteritis, and staggers, and all other acute and
painful affections? There is as much reason to regard
it as an inflammation of the heart as one of the lungs,
and greatly more to consider it as an affection of the
stomach or head, or of both. To show that symptomatic
and idiopathic fevers are, at least in horses, one and
the same disorder, they are continually running one into
the other. The case of the nail in the foot is one irf i
which the febrife originate at the same time with or
very soon after the local symptoms ; such also are burns,
injuries of the head, &c. And, as Professor Thomson
t^lls us, as local inflammation gives rise to constitutional
febrile symptoms, so idiopathic fevers of all kinds, in
their turn, often give rise to, or at least are accompa-
nied by, local inflammatory symptoms. It is very"
possible therefore that a fever may prove the prelude to
catarrh of pneumonia, indeed it is a conmion result

PARI III. '2 Ti

402 O/i Fever.

since we know from practice that these affections are
often so ushered in ; but, for all this, fever is no more
catarrh or pneumonia than it is gripes or staggers, as
postmortem examinations will plainly show.

The fever, then, to which the horse is both idiopa-
thically and symptomatically subject, is neither more
nor less, than the sj/wocAa of Dr. Cullen, common or
simple or inflammatory fever. And so plain a point of
practice is this, in my humble opinion, that we might
as well attempt to deny the existence of inflammation
in horses, as fever. What seems to have led to the
denial has been, the over-eagerness to show the palpable
absurdity of the accounts of the old writers : in very
properly casting away such trash, we have overlooked
the real state of the case ; or, at least, we have not
been patient and unbiassed practical observers, true
and faithful reporters of our observations, but have
suffered our minds to be prejudiced, and our opinions
to be taken into bondage, by those to whom we are too
apt to look up with oracular reverence. To contend,
as GiRARD has done, that fever is meningo-gastritis,
is to reason rather from consecutive disordered function
than from general views of the case ; and to prove that
organic lesions have existed in the very few fatal cases
of fever which are known to occur in any individual's
practice, is not to demonstrate that such constituted
the febrile disorder ; or, why are such not found likewise
in fever from a nail in the foot? The symptoms of
these fevers are precisely similar ; they are only charac-
terized by certain superadded marks or expressions of
local injury or disease, which define the principal ma-
lady to be of some other class, and the febrile connec-
tion to be of a secondary or symptomatic kind : when

On Fever. 403

these signs of local disturbance are not present, and
yet the symptoms are evidently those of common fever,
we are as much entitled to credit in our practice for seat-
ing it in the head, as we are for giving it the name of
meningo-gastritis, pneumonia, catarrhal fever, &c. &c.

Let us now, in conclusion, call to mind, in an order
as natural as we can, the general symptoms of this
most common disorder, common, simple, or inflamma-
tory fever. Should we perceive its approach, we shall
generally disicover that the horse first shows signs of
dullness and heaviness, by hanging down his head,
and manifesting more or less disinclination to move ;
this will probably be followed by symptoms of chilli-
ness, such as staring of the coat, coldness of the sur-
face of the body and extremities ; and I have more than
once seen an actual rig-or or shiverino; fit. These
symptoms may precede those essential to the constitu-
tion of the fever, but they are not commonly heard of,
and in many cases do not take place at all. They are
succeeded by a warm skin, a hot and dry mouth ; a
quick, full, and hard pulse ; respiration perceptibly in-
creased, but not remarkably so, the animal drawing
his breath apparently with more weight or labor than
celerity and pain ; loss of appetite ; costiveness ; uri-
nary discharges altered ; general sensibility more or
less increased. The case of ague related by M. Da-
mo ise a u is a very remarkable one, and bears so well
upon this disputed point, that I see no other way of
supporting a denial of the fact than that of doubting
the existence of any idiopathic or essential fever, as M,
GiRARD has implicitly done, both in men and horses.

In regard to the causes of fever in horses, in the idio-
pathic form nothing seems to operate so generally in

2 D 2

404 On Fever.

its production as change of temperature; it is how-
ever also occasioned by over-exertion, or any cause that
may dispose to plethora of system. It would appear
to be epizootic at certain seasons, and probably may
be also sporadic ; but we lack observations upon these
points.

The indications of cure are those grounded upon the
common principles of inflammation. Venesection is
generally advisable : but we have seldom to bleed
largely, and not often have to repeat it. Purgatives
are the principal internal remedies. They may be suc-
ceeded by hellebore and diuretics. Nitre is a favorite
nostrum of most horse-owners ; and White has gulled
them with gratuitous praise about antimony : the one,
I need scarcely repeat, is a mild diuretic ; the other,
in White's doses, is just as effectual as his squills,
ammonia, and aniseeds are in the cure of broken
wind.

It is very natural for one to ask, as Girard has done,
by what morbid appearances we characterize fever.
Certainly not, I should answer, by any that may
be found in the stomach and bowels. Put the same
question to any eminent human pathologists, whose
minds are unbiased by any favorite theory on the
subject, and a similar equivocal reply will be returned.
Mr. Blatne says, that he has never witnessed fatality
ascribable to fever.^ I have. I have seen several fatal
cases — I have had horses brought to me after hunting
with the most unequivocal symptoms of fever, and those
horses have died, and no organic lesion whatever has
been discernable after death : I know that many mo-
dern practitioners will say that these were cases of
pneumonia, and Girard probably would have named

Fever.

405

them meningo-gastritis ; though, in the cases to which
I alhide, neither the lungs nor the bowels bore marks
of disease. These however are "comparatively rare
cases ; generally speaking, fever m horses is a very
mild and controllable malady ; unless where it is con-
tinually receiving fresh excitement from the som'ce
which gave it rise, as in the secondary form, and
then it not infrequently resists remedy and ends in
death.

LECTURE LXXV.

On Mange, and other Cutaneous Affections.

-IVIange, a name we derive from the French de-
mangeaison, is a cutaneous affection so well known in
its confirmed stage that, had I not reason to believe it
occasionally presents itself in a dubious form at an
early period, any description of its characteristic ap-
pearances might probably be dispensed with. Inve-
terate mange is marked by bare white patches upon the
skin, particularly upon those parts which are thinnest
and most vascular and sensitive ; from these bare
places the cuticle, which has turned white, desqua-
mates and peels off in branny scales, leaving the cutis
underneath exposed, and in the first instance red,
owing to a spot of extravasated blood ; afterwards
however its surface emits some morbid matter which
exsiccates and scabs the spot over. The skin is arid
and harsh to the feel, and often, particularly upon the
side of the neck, is puckered into wrinkles. The parts
remaining covered show more or less progress towards
the same morbid condition : the hair is thin and staring
upon them, it has an unnaturally dry rough feel, and
in places may be plucked out in bunches with the

On Mange, and other Cutaneovs Affections, 407

greatest ease. The desquamated white cuticle, the red
spot or scab, and the unresisting eradication of the
hair, may be taken as the diagnostics of mange.

Mange in horses appears to be a disease of similar
nature to mange in dogs and itch in man : at least.
Professor Coleman says, he has often had reasons for
suspecting that persons looking after mangy dogs have
transferred the disease to horses; and Mr. Blaine
informs us, that he has seen the itch taken from mangy
horses more than once. The disease in all three in-
stances appears to originate in little pimples ; these
form vesicles ; and the vesicle bursts and leaves behind
a small red spot : the pimples seem to exist in great
numbers, more particularly in parts where the skin is
thin, and to run one into another, so as to form, in the
inveterate stages, broad irregular patches, which be-
come covered with a dry, white, morbid cuticle. The
roots of the hair would appear to be secondarily alfected
from the cutis ; for the coat does not come off until
mange has existed some time, and even then, the stub-
born inherence of some hairs in the very middle of the
mangy places is very remarkable. The parts commonly
manged are the face, particularly around the eyelids
and about the muzzle, the sides of the neck, the withers
and shoulders, the armpits, and the thighs.

It seems that mange may be generated either from
immediate excitement to the skin itself, or through the
medium of that sympathetic influence which is known
to exist between the skin and the organs of digestion.
We have, it appears to me, an excellent illustration of
this in the case of mange supervening upon poverty ; a
fact too notorious to be disputed, though there may be
different ways of theorizing upon it. It may be said, in

40<S On Mange, and other Cutaneous Afections.

regard to man, that personal uncleanliness is almost
always combined with poverty, and therefore ought to
be taken into the account ; this argument however
cannot be pushed far in respect to horses and dogs, for
poverty and uncleanliness in them by no means go con-
secutively together, and one frequently exists without
the other. In the place of poverty, Mr. Blaink has
put dehilitij : mange, he says, has three origins ; " filth,
debility, and contagion." Now, with all due deference
to this respectable veterinarian, whose experience has
probably been much greater than ray own, I really do
not conceive that he is \varranted in ranking deOility
among the causes of mange ; for, if it were one, how
numerous would be the cases where poverty had no
place whatever ? Nothing, I apprehend, can more de-
bilitate horses than excessive w'ork, various diseases,
and the long-continued use of certain medicines, and
yet this debility, which is as direct and extreme as it
can be, is not succeeded by mange. But, turn a horse
upon a common where the pasture will just serve to
keep him alive, and it is probable that his poverty will
be attended with mange ; whereas, had the same ani-
mal been turned into good pasture, though all other cir-
cumstances were the same, the certainty is, that he
would not have become manged. It is this last fact that
makes me sceptical about the production of mange from
a dirty or filthy condition of the coat : one animal is
just as likely to foul his skin as the other, and the one
that grows poor breeds mange, while the other comes
up fat and healthy. It is true, that poverty and filthi-
ness often go together ; but in this and other instances
they are distinguishable, and this I take to be the only
light in which the subject can be fairly viewed. Ana-

On Mange, and other Cutaneous A (feet ions. 409

logy may be brought in support of a contrary opinion ;
but, where facts can be adduced that bear directly
upon the point in question, I am little disposed to con-
sult evidence coming from any indirect quarter, however
strong the light it may reflect. How poverty operates
in the production of mange I do not pretend to know,
further than that it seems to originate in some pecu-
liar derangement in the organs of digestion; and
that when produced it does not appear to be curable by
internal remedies, though the rectification of that de-
rangement, and consecutive improvement of the general
health and condition of the animal, indisputably con-
duce to the restoration of the healthy state of the
skin. It is so far a local disease therefore that it does
not appear to be removable by constitutional means ;
but, I think we must admit that it may have, at least
in horses and dogs, a constitutional origin.

There is no question, I believe, but that mange is
the most contagious disease to which horses are ob-
noxious. Horses have been known to take it from
being curried with the comb used about a mangy sub-
ject: the fluid included in the pustules most probably
contains the infectious matter ; for it is absolutely ne-
cessary for contact, mediate or immediate, to take place
before the disease can be communicated. My father,
in my recollection, has had as many as two hundred
horses manged in the Infirmary at Woolwich at one
time : I do not mean to insinuate that these animals
all caught the disease, but it appeared to us highly
probable that contagion was principally operative in
the mischief.

In the human subject, as every one has heard, sul-
phur is the ' remedy for itch ; and the various expcri-

410 On Mange, and other Cutaneous Affections.

ments made by surgeons at different times appear to hare
gone so far to establish this fact that there would seem
to be a something in sulphur that combats itch more ef-
fectually than any other application with which we are
acquainted. Mercurial preparations will also cure itch,
but they are not so certain in their operation as sul-
phur. This has led to a pretty general use of sulphur
in mange ; but, though I do not mean to call in
question the success of those who employ it, I must
contend that it falls short in efficacy of what I am
about to recommend : at the same time, those who are
prepossessed in its favor will find the subjoined formula,
I believe, as neat and convenient, and as curative as
any of the sulphurous compositions*. Leaving sul-
phur, we have displayed to us' a vast variety of appli-
cations for mange : we have ointments, liniments,
lotions, Sec. in abundance — choice enoug-h even to
satiate the nostrum-seeking disciples of White. Fe-
RON tells us, that the application of blisters in the
mange, if properly modified and judiciously applied, will
be found a real specific in this distemper, but their ap-
plication must sometimes be repeated more than once."
Had he said cantharides properly modified and ap-'

* R Sulphuris ^vj. , , .^^

01. Communis fcj.
Terebinth. Vulgaris Jij. M.

or this,

R Sulphuris 5iv. \
Vcratri Rad. pulv. Jij.
Hydrarg. Oxy-mur. pulv. 5j.
01. Communis ibj. M.

The Sulphur Vivum, which is cheaper, will answer this purpose
quite as well, I believe, as the Sublimed Sulphur.

, On Mange, and other Cutaneom Affections. 411

plied one might have been inclined to make trial of it ;
but a blister over the whole surface of the skin appears
to me to be such a formidable remedy that I take it
the animal had better remain manged. If it be worth
while to insert any of them here, I may as well give
a liniment that w^s commonly used at the Veterinary
College some years ago * : what the present remedy is
I do not precisely know. After all however, and I can
speak with confidence, because several hundreds of
horses — perhaps I might say thousands, have experi-
enced its efficacy, I know of no local application equal
in effect to a mixture of Barbadoes tar and train oil f :
it gently stimulates the surface, suppresses the morbid
irritation, restores healthy action, and ultimately so
supples and softens the skin that it acquires the feel
of chamois leather, and the coat its former fineness
and glossy aspect. If the season admit of it, a sunny
day is to be preferred for inungation : the operation
should be perfomied with a soft brush, with which the
ointment ought to be well rubbed into the affected
parts. A second inungation may be required at the ex-
piration of a week, and, about the same interval, should
the case be an inveterate one, probably a third, and
even a fourth. Horses who are standing in the stable
will be benefitted also by soiling and paying some
attention to their digestive functions ; but the best
situation for mangy horses is the grass-field, where
they may be turned out together, and even, I believe

* R 01. Communis fcj.

Spts. Terebinth. Jiij. Misce, deinde adde

Hydrargyri Oxy-mnriat. 3f$. solut. in Acid. Muriatic. 3ij.

f R Petrolei Jiv.

01. Communis ftj. M. fiat liniment, tcjtid. applicand.

412 On Man^ef and other Cutaneous Affections.

without risk, with sound horses, providing they are
previously thoroughly anointed. Though it is not ab-
solutely necessary, or invariably considered worth the
trouble, to wash these subjects with soap and warm
water before the dressing is renewed, I am of opinion
that it is a part of the treatmeat that ought not to be
disrep-arded when the weather is warm, unless the
horse be at grass, or be about to change his coat, in
which cases a single final ablution may be all that is
required. Eveiy article of saddlery and stable furniture
which may have rubbed against his mangy surface, it
will be requisite to soak and thoroughly cleanse before
they be used for other horses ; and the stall (together
with its rack, manger, &c. in which he stood in a state
of disease) ought at least to be properly washed with
soap and boiling water, if not fresh limed or painted.

Very often, horses are brought to us on account of
rubbing various parts of the body, particularly the root
of the tail, the mane, and perhaps the head and neck
as well : the hair is ruffled and worn by the friction ;
indeed, sometimes the places are rubbed quite bare.
The cutis however remains commonly unabraded, and
the hair, though worn down by friction, still firmly
adheres by its roots : to which may be added, there is
no appearance of pustule, nor are there any red spots.
These cases are generally referable to what is vulgarly
called " heat of blood," or, in medical phraseology, to
plethora and constitutional excitement ; and therefore
require some mild antiphlogistic course, such as a dose
or two of purgative medicine, perhaps the abstraction
of a small quantity of blood ; with which may be re-
commended, increased exercise to produce occasional
sweating, and bran mashes in lieu of corn once or twice

\

On Grease. 413

a day. I am in the habit of prescribing also for these
subjects one of the subjoined lotions*, with which the
parts rubbed should be sponged frequently in the
course of the day.

Now and then we see horses, particularly in the
spring of the year, suddenly breaking out, over the body
generally, into lumps or pimples : this eruption is called
by our farriers a surfeit. Though commonly the at-
tendant of full condition, it seems to arise from some
mysterious derangement or other in the digestive ope-
rations ; for it will often disappear as suddenly as it
came on, in which respect it bears some analogy to
urticaria or nettlerash in the human subject. A case
of this description was treated by my father last sum-
mer which was no less remarkable for the number, size,
and universality of the lumps, which were as large as
common marbles, than for disappearing in the course
of a few hours on one day, and breaking out afresh
on the third or fourth day following ; and this was
repeated several times. The treatment for these cases
consists, in bleeding, according to the apparent dis-
position to plethora ; ifi exhibiting alterative or laxa-
tive medicines, alternated with mild doses of calomel,
hydrarg. c creta, or blue pill ; and in directing walking
exercise for three or four hours in the course of the day.

On Grease.

Grease may be defined to be, an issue from the cuta-
neous pores of the heel of a peculiar, greasy, offensive
matter; and may be said, invariably, to originate

* R Acid. Sulphuric. 3 ft-
Aquae Ibj. M.

R Hydrarg. Oxymur. 3ij.
Aquae Rij. M.

414 On Grease.

in inflammation, or at least in increased vascular
action.

The heel of the horse bears some analogy to the ax-
illa of the human subject; it is furnished with cutane-
ous glands of a particular kind which supply a secretion
of an oily or ceruminous nature, differing from any other
in appearance and odor ; and this secretion lubricates
the skin, supples and softens it, and protects it from
the irritation of dirt, and, to a certain degree, from
the contact of moisture. Mr. Blaine considers the
inflammation, of which grease is the consequence, to
be of a specific kind; but, looking into its symptoms,
its progress, and the circumstances under which it makes
its appearance, I really do not see the necessity of
calling any specific influence into our ratio symtomatum.
The peculiar nature of the morbid matter is what Mr.
Blaine rests this hypothesis upon; but I can see
nothing more in the case myself than that, the structure
of the part being peculiar, inflammation brings forth a
secretion from it which in its natural as well as morbid
condition is also peculiar. However, not to dilate on
this point, one that admits of a variety of elucidations,
grease, I repeat, originates in inflammation, and on
the principles of simple phlegmon we shall find its phe-
nomena and causes to be explicable, and its cure cer-
tain. Professor Coleman's theory on the production
of grease used to be this — The heels being very remote
parts from the heart, and the circulation in consequence
proportionably weak in them, a congestion or stagna-
tion of blood takes place within the capillaries, which
those vessels have no other way of relieving themselves
of but by pouring it forth in the foim of grease. All I
have to say about the actual condition of the capillaries

0» Grease.

415

myself, is, that, as the case resolves itself into one of
inflammation, I should conceive that those vessels may
at one time be in a state of increased, at another of
diminished action, according to circumstances ; that the
tumefaction was rather a consequence of effusion than
of distension : and that au2:mented secretion mijjht re-
Bult from increased action as well as from an oppressed
or debilitated circulation. Professor Peall draws a
comparison between grease and chilblain in the human
subject. " The disease is, in truth," he says, " the
chilblain of the horse." So far that they are both
local cutaneous inflammations in parts remote from the
heart, and induced by vicissitudes of heat and cold,
there certainly is an analogy ; but grease differs from
chilblain in that which constitutes its very essence, viz.
in its characteristic sign being that of a peculiar greasy
issue, nothing of which kind happens in chilblain : in
fact, one is seated in a part of the skin furnished with
a peculiar glandular apparatus ; the other aflects an
ordinary part of the same tissue, simply because it is
exposed, and in consequence subjected to a debilitated
or disturbed circulation.

The etiology of grease throws considerable light upon
its veritable nature. Horses who are at pasture or in
strawyards, in situations, in fact, where heat and cold
are not naturally, and cannot be made artificially, sud-
denly operative upon the heels, rarely have grease. Those
that have grease in stables are mostly coach and cart
horses, having thick fleshy heels, and white legs, who
are very subject to get their heels wet and do not com-
monly have such pains bestowed upon them to dry
their legs as hackneys, hunters, and racers have: in-

416 On Grease.

deed, among the latter, grease is a very uncommon
disease. Such horses also stand in stables hot and
filthy from dung and urine, the very exhalations from
the litter of which, ammoniacal and stimulatino- as
they are knovra to be, may, as Professor Peall
plausibly argues, prove an additional excitement.
Grease formerly made great ravages in the Cavalry and
Ordnance service ; whereas, at the present day, the
disease is scarcely known. This change for the better
is ascribable to three causes : to the proper ventilation
of the stables, the greater attention paid to grooming,
and to the presence of a veterinary surgeon who checks
in the outset any such casual occurrence. I have heard
Professor Colemajs[ say, that that soldier deserves
punishment whose horse has become greasy ; and I per-
fectly agree with him — it is, as the cavalry are now sta-
bled and shod in this country, in the power of every
dragoon to preserve his horse free both from grease and
from thrush.

Light-chesnut and white-legged horses have been re-
marked to be more particularly the subjects of this dis-
order where great numbers have been simultaneously
affected. The autumnal and winter seasons, and cold
and wet springs, are the times when grease prevails,
and particularly in frosty weather when snow is present :
great numbers of cavalry horses have been attacked on
return from camp. The condition of system under the
influence of which horses change their coats is said to
favor its production. The hind legs are the parts
commonly greased ; it is seldom found in the fore legs :
the rationale of which is, that the hind heels are fur-
ther removed from the heart, ergo, more predisposed to

I

On Grease. 417

inflammation ; and, at the same time, are more ex-
posed to the vicissitudes of heat and cold, from their
liability to get wet, and the little comparative pains
taken to dry them afterwards, ergo, have the exciting
causes applied in a more forcible degree. The same
principle of reasoning applies to horses who are light-
chesnut-colored, have white legs, or are changing their
coats. By no means an infrequent cause of grease,
when proper management is wanting, is a blister to
the hind leg ; and, if any thing goes to prove the simple
or common nature, as well as the locality of the inflam-
mation, it appears tome to be this ; Mr. Blaine how-
ever admits this most fully, and yet he contends for
the specific nature of the disease : I cannot, I must
acknowledge, reconcile all this ; analogy, which one
might be apt here to resort to, turns decidedly against
Mr. Blaime's pathology.

^ Sainbel, who wrote ^' An Essay on Grease," for
which he was presented with a prize by the Royal So-
ciety of Medicine in France, thus commences his paper
— *' The grease is in general a cutaneous chronic alfec-
tion, sometimes mflanimatory, sometimes infectious ; and
I have known it contagious : it invades the legs of
horses, asses, and mules ; but seldom attacks those of
the ruminating species." We are told that cow-pock
had its origin in the transfer of the matter of grease
from the heel of the horse to the teat of the cow, and
that the disease may be communicated to the human
subject by inoculation with this matter, the same as
with that taken from the ulcerated teat of the cow ;
some have gone further than this, and said that glanders
and farcy could be generated in this way : the accounts
of these strange transactions however have made but lit-

PABT III. 2 E

I

418 On Grease.

tie impression, for we hear nothing of them nowadays,
and this is not a very bad criterion of their want of
truth and foundation altogether. I have heard Profes-
sor Coleman say, that there never was a well authen-
ticated case of cow-pock being produced from grease ;
and, I verily believe myself (though I do not know
that the fact has been satisfactorily experimentalized on)
that there is no truth of its being communicable among
horses. In certain seasons and situations the disease is
certainly sporadic ; but, then, the causes are too mani-
festly operating among horses under the same circum-
stances to refer its production to infection or contagion.

The symptoms of grease, in its simplest form, are — an
exudation of a greasy, offensive matter from the skin
covering and surrounding the heel, attended with pre-
ternatural heat, redness, tenderness, and occasionally
general tumor of the heel and fetlock. Soreness or
lameness on first leaving the stable is commonly per-
ceptible ; though it is seldom in sufficient degree to call
attention to the disorder, the first intelligence of which
is commonly communicated by the groom. And here I
may remark, that the presence of grease is a pretty in-
fallible test of negligent grooming ; for, as may be in-
ferred from this exposition of its nature and causes, a
horse whose heels are kept dry and clean, and never suf-
fered to grow dry of themselves after having become wet,
will be in little danger of contracting grease. Should
the diseased action not be corrected, the inflamma-
tion extends up the leg, which in consequence takes
to swell, and grows warm, and tender on pressure ; so
great indeed is the morbid sensibihty of the heel often
in this stage that if the part be but touched the animal
instantly catches his foot off the ground, evincing

On Grease. 419

considerable pain. The greasy issue, by this time aug-
mented in quantity, stands in large drops among the
hairs, which grow strong and show an inclination around
the point of the heel to become bristly. No affection
causes more pain or soreness on motion than grease,
the heel itself being so very moveable and sensitive
a part ; when both hind legs are violently affected,
the animal is often so lame that when first taken
out he can but with great awkwardness (evidently
from excessive soreness felt, particularly in extending
the heel) even walk at all ; after he has walked for
some time however, this soreness diminishes greatly or
entirely leaves him, and he will trot with much appa-
rent freedom : this accounts for the many greasy horses
we see in constant use. We may explain this relief,
by saying, that exercise has produced some absorption,
and this has taken off the distention and consequent
tenderness and inability to the free motion of the joint,
and has moreover provoked a copious secretion which
has abundantly lubricated and softened the skin of the
heel, and thereby further diminished its morbid sensi-
biUty. As this does not therefore incapacitate the animal
from working, the case is sometimes neglected and
becomes inveterate grease. Pustules arise in various
places, mostly around the upper and back part of the
heel, in consequence of the irritation occasioned by the
discharge ; these burst and expose a raw surface from
which granulations arise in clusters resembling (as
Sainbel happily expresses it) *'the outward coat of a
pine-apple :" these pustular excrescences are called by
our farriers grapes. The morbid action of the skin con-
tinuing unchecked, grapes, which are nothing more in

2 E 2

420

On Grease.

their origin than granulations springing from an inflamed
surface, shoot out into irregular spherical forms and at
the same time swell considerably, so that many of them
(though they vaiy greatly in size) grow as large as
segments of marbles ; in the course of time they be-
come of a schirrous or rather a cartilaginous texture, and
1 have found them assuming the nature of horn, which
would appear to be their natural tendency or ulti-
mate change. The skin itself all this time is gradually
altering its texture : it becomes morbidly thickened,
and assumes a cartilaginous toughness and hardness in
accordance with the grapy excrescences ; I have got a
preparation before me in which it is thrice its natural
thickness, but I have never met with it horny.

Altogether, the heel in this condition puts on the ap-
pearance, were it not for the color, of a full-blown cau-
liflower : and this seems to be the maximum of viru-
lence. In the mean time, also, the hair has gra-
dually fallen off, so that the grapes are either quite bare
or very thinly bestrewed with hairs which stand out
after the form of bristles from a hog's back. A puru-
lent greasy discharge, here and there tinged with blood,
issues from the skin not yet covered or altered by grapes,
the fetor of which is intolerably noisome ; at the same
time, there is something in the odor of it which is pecu-
liarly characteristic of the disease. Inveterate grapes
are intensely reddened from their high degree of vascula-
rity, and are exquisitely sensitive, giving great pain when
touched or pressed. They commonly sprout from the
upper and back part of the heel ; rarely from the coronet,
(to which the disease extends occasionally,) but very often
from the hollow of the heel ; though it frequently hap-

On Grease.

421

pens that they spread up the hind part of the leg, they
rarely reach the hock. The leg acquires in some cases
an enormous bulk, so that the limb from extreme sore-
ness as well as swelling, is considerably pained and in-
convenienced in action : in fact, the part altogether, to
use Sain B el's translated expression, is " a cumbersome
mass of disease ;" and, I may add, a most obnoxious
member from the rancid oily issue which is continually
running from the crevices between the grapes, mingled
with the purulent bloody matter discharged from the
ulcerated surfaces of the grapes themselves.

The treatment will be very simple, or be more or less
complicated, according to the duration, stage, and
virulence of the disease. Professor Coleman, in
lecturing on this part of our subject, has always shown
more than ordinary solicitude in inculcating the doc-
trine, that, as wet or moisture is the common cause
of grease so in any form it will, generally speaking,
prove injurious in the treatment. This appears to me
however to admit of such qualifications as will go al_
most or quite to undermine the general assertion. In
the first place, we certainly are not warranted in lay-
ing it down as an axiom in medicine that what bi/
predisposition gives rise to a malady is not to be em-
ployed as a remedy, else why are snow and ice-water
recommended as the best remedies for chilblains? —
cold affusion in fever, pneumonia, See? for, I must
remind you here, that moisture is not the exciting,
but the predisposing cause of grease : the disease
would not follow its application at all unless the heels
had re-action excited in them from other causes. And
in the next place, even this wet or moisture under cir-
cumstances the most favorable to the production of

422 On Grease.

grease, viz. in a hot stable, would not in all pro-
bability give rise to any such ill consequences were
the circulation kept up until the parts became dry
again, instead of suffering it to be rendered weak and
tardy by the cold resulting from evaporation : a prin-
ciple which, once understood, will direct us in the pro-
per use of wet applications for grease, should practice be
found to give them the preference.

Let us now proceed to give the remedies ; and, in
so doing, endeavour to divest the subject of treatment
of that complexity in which our best authors seem
to me to have obscured it by paying more attention to
one another than to the simple dictates of practice.
For the sake of simplification, let us put down our
cases summarily, and then prescribe for them.

Should the case be a mild and recent one, auo--
mented issue be the only ailment, some simple as-
tringent application will be all that is required*.
A powder is generally employed, after which I myself
prefer the form of ointment §, and for this reason : that,
as the astringent powder has a tendency to suppress
the secretion, the discharge will, sooner or later, be-
come arrested altogether, at which time, the heels

* H Piilv. Aliiiniilis

■ Bol. Ariucn. aa p. req. M.

or this,
\\ Pulv. Carb. Ligni

Calamirice aa p. s^. M.

§ P< Tiilv. Altiminis 3ij.

Ungt. Simplicis . M.

or this,

R Ungt. Citiini

Simplicis p. vcx\. M.

On Grease. 423

being dry, the ^kiii grows hard and contracted and
disposed to crack, all which, I conceive, is in a great
measure prevented by the unguent artificially smeared
over the surface. Though I ordinarily use the pow-
der, therefore, in the first instance, I substitute some
mild astringent unguent as soon as the discharge has
become suppressed. Should the legs be oedeniatous,
walking exercise twice a day in a dry and clean place
will be beneficial, and a diuretic ball may be adminis-
tered every other night.

But, in a case in which the heels are hot and
tumefied and tender — in other words, in which inflam-
mation is very active, I have no hesitation in saying
that we ought to mitigate it in the first instance by
assuasive means before we think of employing astring-
ents. Some recommend fomentations, but they are
inconvenient applications and possess no advantage
over a common poultice. And of all poultices the bran
poultice, from an absorbent property it possesses,
is one of the best. Where there is much fetid dis-
charge however, and a degree of malignancy about
the case, a poultice of charcoal is to be preferred, one
that possesses still greater astringency and is com-
monly attended with the best consequences. At the
same time purgation should be put in practice, low diet,
and even in some cases the abstraction of a little
blood from the thigh will be advisable. As soon as
the inflammation has subsided, astringents may be
employed ; they will require however to be stronger *

* R Cupri Sulphar. 3ij.
Ahiminis 3ft.
Bol. Armen. ^. M.

424

On Grease.

than those used for slight cases, and (what is very
important to remember) they ought, not merely to be
smeared over the heels, but spread upon pledgets of
tow and kept applied, by means of bandages, for
two, three, and even four days together, without tak-
ing the horse out of the stable; during which time
it is a part of my practice to give a strong dose of
purgative medicine, should that not have been done
before : at all events, the bowels should be kept
moved. On the third or fourth day, when the ban-
dages come to be removed, the legs will commonly be
found much swollen, but the heels very considerably
improved. It will then depend upon their condition
whether the bandaging and liniment are to be re-
newed, after the horse has been walked out for at
least two hours, or whether the cure be thousrht suf-
ficiently advanced to be completed with mild astrin-
gent applications, powders and subsequently oint-
ments. Also give, from time to time, diuretic balls.
Rowels are not adapted to do much good in grease. It
is very important that due attention be paid to exer-
cise. After having been under the operation of the
bandaged dressings for two or three days, the animal
will require, for at least two hours, to be walked

£t contere in pulv. subtiliss. deinde adde
01. Commun. ^iij-
Ut fiat linimenium.

or this,
R Cupri sulphat.
Calaniinne aa §j.
In pulv. redact, et miscc cum
01. Commun. ^iv.
Or, the Citrine ointment, made thin with oil, may he used.

On Grease.

425

about, prior to any repetition of the dressings ; or,
should it be a case not requiring bandages, exercise
for one hour ought to be given both in the morning
and afternoon. It is also of some inij)ortance that the
animal stand in a clean and ventilated stable ; and if
it be large enough for him to be let loose in, that is
by far the most suitable.

In consequence of grease being comparatively a
rare disease io what it was twenty years ago, and from
the improved state and diffusion of the veterinary
art, it is by no means common nowadays to meet
with an inveterate case of chronic malignant grease ;
and, indeed, such cases are not to be desired, for they
are vastly troublesome and tedious to treat, and in
the hands of timid and inexperienced practitioners
are not recoverable at all. In the year 1821 a case
of such duration, virulence, and malignancy was sent to
my father to treat, which, in the end he completely re-
stored, that I do not think I can draw up a more sys-
tematic and efficacious plan of treatment than the
perusal of this case affords ; I shall therefore relate it.

June I9th, 1821. Admitted a chesnut mare, seven
years old, rather low in condition, who has had grease
for these last two years. The disease originated in
the ordinary way, and has arrived at its present height
and malignancy from neglect, continued exertion of
the parts, and occasional mal-treatment. All four
heels, but particularly the hind, are studded with
prominent grapes, thinly clad with bristled hairs,
through which their bare surfaces appear intensely
reddened, and here and there are issuing blood. In
places where there are no grapes the skin exhibits a

426

On Grease.

red, rough, elephantiasical aspect. The grapes ex-
tend for several inches above the fetlock ; but. they are
all situated at the posterior parts of the legs. The
hollovs^s of the heels are entirely covered with ulcerated
grapes. A greasy and extremely offensive matter
issues from every part of the morbid surface, which
lodges in the crevices between the grapes as if so miich
oil had been poured thereon. On the same afternoon
on which she was admitted, my father submitted her
to the following painful operation. Having properly
secured her standing, with a sharp scalpel he com-
menced paring off the grapes from the hind heels,
upon a level with the surface of the skin, in doing
which he found it necessary to have firing irons near
him to staunch the hemorrhage as he proceeded'
which, owing to the high vascularity of these excres-
cences, was very considerable; the cautery however
was prepared to be used with another object, that
destroying the morbid surface from which the grapes
had so long been growing. All the larger grapes
having been in this manner removed, (which proved
to be cartilaginous, some even horny, in their com-
position) the remainder of the diseased surface was
lightly seared over, and the mare was returned to the
stable, and dressed with the following liniment, which
was spread upon pledgets of tow, and they were con-
fined by many-tailed bandages : —

R Cupri Siilphat. in pulv. 5j.

Ahiminis Jiv.

01 Communis Ife ij. M. pro Linimento.

Both the hind and fore heels (although the latter
had not been operated on) were dressed with this ; and
a brisk purge was given afterwards.

On (i reuse.

427

24M. The ' diseased parts were covered over with
sloughs ; these being wiped off, the surface presented
a raw and highly vascular appearance, and now show-
ed distinctly the smaller grapes that had been left
unpared. She was cast, the fore legs were operated
upon as the hind ones had been, and the hind legs
were also rid by the knife and cautery of many more
grapes, which before were hidden by larger and more
prominent excrescences. She was afterwards dressed
as on the first occasion; and some of the Unguent.
Ferri Acetatiswa.ii applied to her frogs, in which thrushes
had made their appearance since last dressing

27th. Since the 24th some little fever has been
hanging about her; her appetite has been impaired,
she is tucked up, and has evidently suffered from
pain. She was walked out, and afterwards dressed
as before.

30th. A raw surface pretty free from grapy excres-
cences now presents itself. Her legs were simply
smeared over, without any pledgets or bandages, with
the ointment, and (the weather being warm) she was
afterwards turned into a grass paddock.

.lull/ 4th. An ichorous discharge, but which is not
very offensive, issues from the ulcerated surfaces.
Ointment repeated.

Wi. The surface looking florid and healthy. What
grapes still remained unpruned were to-day touched,
by means of a feather, with nitric acid. They in-
stantly turned yellow, and a process of solution began
in them. The surface generally was washed with
Sol. Cupri Sulphatis— 5j.— ad Jj.

Wth. Sloughs caused by the acid, turning out, and
leaving deep excavations. Blue solution repeated.

428

On Greaie.

\5th. The heels have begun to granulate, and in
places are showing signs of cicatrization. Unguentum
Aluminis.

30t/i. Since the I5th the dressings have been mild,
and such as are promotive of the granulating process.
The heels are making great progress towards health.

After this, nothing worth mentioning was done.
Not only a new surface, but in most places a new
skin, was eventually formed, and the mare was ulti-
mately restored to her master perfectly sound, with
some trifling induration of the parts which had so
long been the seat of this noisome disease.

LECTURE LXXVI.

On Stass^ers.

This is a generic name for affections of the brain,
taking its origin from a common and prominent symp-
tom denoting tliem, that of the horse reehng or stagger-
ing in his attempts to walk. The brain is an organ
much less exercised in the brute creation than in man :
the latter derives from it the various passions and intel-
lectual faculties comprehended under the term mind;
the former has simply superadded, by it, over and above
common sensibility, instinct and reason enough to pro-
vide himself with food, avoid danger, and seek sexual
intercourse. As might be inferred from this diminished
importance and use, the organ in animals is consider-
ably less subject to disease.

In horses, the brain may be actually or primarily
diseased, or it may be sympathetically or secondarily
affected ; and these affections will, in certain stages,
give rise to the same symptoms ; so that, were it not
for other concomitant circumstances, we should be
unable to distinguish them. I shall first show how the
organ is sympathetically affected.

No fact is more notorious in physiology than the sym-

430 On Staggers.

pathy constantly operating between the head and the
stomach : a violent blow upon the head makes a man
sick at stomach, and disordered digestion is the com-
mon cause of head-ache. What disorders the human
stomachy generally speaking, is food improper in quan-
tity or quality, or taken at improper intervals. Now,
let us apply these few simple and general facts to horse
pathology. Horses who are kept long fasting and then
have provender spread before them in profusion, will be
likely to glut themselves until they have crammed their
stomachs with food and an uneasy sensation is created
which deprives them of any appetite for more. This
uneasiness is manifested by the following symptoms.
The animal becomes dull and drowsy, and grows insen-
sible to what is passing around him ; he hangs his head
under the manger, and loathes what food remains be-
fore him ; the drowsiness and insensibility increasing,
he rams his forehead against the rack or any resisting
body before him, stands fixed in that position, and falls
into a state approaching lethargy : this last is the most
remarkable, and may be regarded as the diagnostic
symptom. The pulse is either unaltered, or it is slower
than in health — about 40. He labours somewhat
in drawing his breath, though his respiration in this
stage is not commonly accelerated. If he be suddenly
roused however, both the pulse and respir-ation will be
momentarily hurried. When led out, he walks un-
steadily or staggers about. His extreme parts are cold ;
his bowels obstinately constipated ; and, according to
Mr. Blaine, who sets it down as a constant and in-
variable symptom, though I must confess I have over-
looked it myself, there appears a yellowness of the mu-
cous membranes of the nose, eyes, mouth, and rectum.

On Staggers. 431

Unless he be relieved from this lethargic and insensible
state, he is gradually aroused from it by symptoms of
inflammation of the brain, which commonly make their
appearance in a more or less marked degree before death ;
but the delirium does not mount to that heio-ht which it
does in what is called, in contra-distinction to this,
which has received the epithet of sleepy, mad stag-
gers.

Professor Coleman considers that this disorder
takes its rise from over-distention of the stomach. He
was once consulted about some horses among whom
there had been a strange and unaccountable fatality,
and he found that they were in the habit of conti-
nuing at work for ten hours together during the day,
and on their return home at night were abundantly sup-
plied with food. The Professor, with his wonted pene-
tration, soon discovered the source of the evil; and
ordered, for the future, that the horses should be fed
in the middle of the day also, by means of nose-bags ;
which salutary practice put flight to the epizootic.
Now, this is certainly a strong case to show the sto-
machic origin of the malady ; and yet I cannot refrain
from entertaining doubts that, after all, over-distention
is the exciting or efficient cause. Else, how comes it
that gastric tympany * does not likewise produce stag-
gers ? The stomach is quite as much, nay, more dis-
tended in one instance by air than it is in the other by
food : for I have seen two cases in which it has burst,
and in another the organ was full thriee its ordinary vo-
lume. If mechanical distention be the cause, surely
here it was in full force, and ought to have been effec-

* Vide Part II. Lecture xliv. page 424, in a note.

432 On St agger a.

tive! Mr. Cordeaux V. S. Royal Artillery, has
lately done me the favor to communicate to me from
Ireland an account of two fatal cases, both of which
succeeded voracious feeding after long-continued hun-
ger : in one of them, the stomach with its contents
weighed 45 lbs., the other wanted only a few ounces of
50 lbs. ; they were both enormously distended. But,
if distention be not the exciting cause of the cerebral
derangement, what is it ? I cannot divine myself, un-
less it be the presence of such a load of raw indigested
matters in the stomach, whereby its functions are de-
ranged, and its surface for want of secretion probably
irritated by them; for Mr. Blaine tells us, that in
every case that he has examined, there has been "an
inflamed state of the depending portio?i of the great cur-
vature of the stomach towards its pyloric orifice " differ-
ing from any other inflammation of the part — one sui
generis, and he has therefore named the disorder,

"specific inflammation of the STOxMACH."

I must protest myself that I have a great aversion to
the epithet specific as it is commonly employed in medi-
cine, because it seems to interdict all further inquiry,
and yet does not, after all, help us out of our difficul-
ties ; and it is for this reason that I do not consider the
point worth contending until we come to discover in
what this specific inflammation differs from that which
is common in its nature. What is called the hove in
cattle is commonly mentioned here byway of illustrat-
ing this part of pathology ; but, I should say that the
hove was a tympanitic aflfection, that air and not food
stretched the paunch, and it strikes me that the symp-
toms are not those expressive of pain in the head, but
of pain in the belly : could the head here be proved to

On Staggers. 433

be affected, it would certainly operate in favor of the
theory of distention.

The treatment of this disease has been notoriously
unsuccessful: Mr. Blaine says, "I never witnessed
a successful issue." It may be deemed arrogant in me
to attempt to show cause for this universal failure, but
I cannot help thinking but that we have been strangely
erring in pointing out remedies for this malady. Of
what avail can we expect our aloes and our oil, &c. to
be, introduced into a stomach, as they are, already
crammed to distention with indigested food ? Phlebo-
tomy certainly will tend to relieve any congestion or in-
flammatory action there may exist in the brain ; but,
the main question for us to consider, is, whether it can
have any effect in unloading the stomach. Practi-
tioners are in the habit of expressing their surprise
at the obstinate apathy of the bowels ; whereas, is it
reasonable to suppose that 12 or even 20 drams of aloes
can have any effect when they can pass no further than
the stomach ? Assuredly, in some few cases it is pos-
sible that active stimulants may make such an impres-
sion upon the stomach as to excite contraction in it ; in
the generality however, the atony consequent upon the
over-distention seems to render that hope even bi^t^ a
forlorn one. It is perhaps more easy to expose the in-
efficacy of such means as these than to point out mea-
sures likely to prove effective in removing the cause of
the evil. Now that we have got tubular probangs, and
can without much difficulty pass them into the stomach,
in my opinion it would be advisable so to do, and in-
ject through the tube a quantity of any tepid innoxious
fluid, and thus endeavour to evacuate the contents of
the stomach by copious dilution : the insensible state in

PART HI. 2 F

434 On Staggers.

which the animal is at the time, is veiy favorable for
the experiment ; and it is one that I shall certainly put
into practice the first opportunity I may have. This
should be followed by a potent purgative in a fluid form,
combined with some stimulant*, and a detraction of
blood, large in proportion to the apparent signs of con-
gestion in the brain, or gastric inflammation, and to the
duration of the disorder. These evacuations should be
followed up by blisters to the head, and over the region
of the stomach ; and the purgation may be promoted by
enemee. After this, hellebore will be found particu-
larly serviceable in abating any impulse of blood to
the head, combined with aloes or calomel as often
as the bowels appear to require their action renew-
ing.

What is vulgarly called mad staggers is neither more
nor less than

Inflammation of the Brain — fhrenitis, 2i3 it is
technically named. Bracken considered it as an
apoplectic affection ; but the lethargic stage is not
marked by that suspension of sensation and voluntary
motion, and that profound sleep, which characterize
apoplexy, and we know from experience that this stage
is only the prelude to the phrenetic paroxysm which con-
stitutes the veritable mad staggers. Mr. Blaine, I
conceive, has very properly refused to adopt that ap-
pellation, and has substituted for it phrenitis.

It appears that what we call sleepy staggers may de-
note disorder either of the stomach or head ; but, that

* R Decoct. Aloes.

Tincfc. Cardamomi vel Zingiberis aa ]fej. M.
Fiat haust. statim exhibend et repetend. p. r. n. or the tinctura
crotonis may be substituted for the decoct, aloes.

On Stas;ore?^s. 435

the stomach-affection never gives rise to mad staggers.
Now, as the mad staggers is commonly ushered in by
the lethargic or sleepy symptoms, it is a point of vital
importance in practice to be able to distinguish between
these affections, in order that we may know fw certain
whether our remedies must be directed to the head or to
the stomach. Mr. BlaixNE gives us as diagnostics,
the yellowness of the eyes and mouth, and '^spasmodic
twitchings" of the skin, which, he says, eminently cha-
racterize disorder of the stomach : I cannot charge my
memory at the present moment with these characteris-
tics ; but, I would add, that here, as in many other dis-
orders, the circumstances of the case ought to form, in
my opinion, a very prominent feature in the diagnosis.
The horse may be attacked at grass, as well as in the
stable, or there may have been a previous long absti-
nence, or food of a luxuriant nature may have been
supplied in improper abundance, all which circum-
stances would lead ijis to refer the malady to the sto-
mach. On the other hand, an evident disposition to
plethora, an attack immediately following excessive ex-
ertion, or continued exposure to a meridian sun, would
induce us to look to the head.

There are particular states or affections of the brain
in which the animal manifests the same somnolency and
lethargy as characterize disorder of the stomach : horses
so affected will stand, commonly with their heads
thrust against some hard body, with their eyes closed,
and doze or sleep until they actually fall down on a
sudden, often backward, in the stall; this, suddenly
awaking them, startles and alarms them greatly, they
hastily get up, but soon relapse into their former stupor.

2 F 2

436 On Staggers.

There is in the eye of such horses a remarkable stare
■ — a fuhiess and stupor that seem to express a sense
of weight in the head, which is hung down under the
manger in a state of extreme dejection. The pulse
at this time is often not more than 40° ; never, I be-
lieve, does it exceed its ordinary frequency, unless any-
thing happens to rouse him, such as the shutting of a
door or suddenly approaching him, and then it instan-
taneously rises into extreme quickness, from which
it as suddenly sinks again into its former tardiness.
In some cases, the breathing is stertorous. His ap-
petite all this time is not so much impaired as one
would expect : place hay or corn before him, and rouse
his attention to it, and he will probably commence
feeding ; and yet, such is occasionally the irresistible
somnolency that I have seen the animal fall into a
doze literally with the hay in his mouth. The bowels
participate in this torpor, and are obstinately consti-
pated. These lethargic symptoms may continue for
several days, and at length end fatally ; or they may be
succeeded by the phrenetic paroxysm, which is still
more likely to prove fatal. The symptoms are those of
wild and furious delirium. The first warning we have
of its approach may be commonly gathered from the
rising of the pulse, acceleration of the breathing, and
the renewed lively aspect of the countenance. The eyes
become animated, have a vacant and alarming stare, and
the pupils dilated ; the conjunctiva is flushed ; the nos-
trils are erected, their lining membrane highly redden-
ed, and the breathing grows quick and painful. The
pulse becomes full and strong, and very irregular ; at one
time it is very quick, at another it intermits ; or now it

On Staggers. 437

is hurried, now it sinks again. Fits of delirium seize
him from time to time : lie furiously dashes himself
about, throws himself down, lies in a state of tempo-
rary insensibility, his eyes appearing as if ready to
start from their orbits, his pupils dilated, glassy, and
insensible ; suddenly he rises from this comatose state,
and either becomes again convulsed with phrensy and
pain, or relapses into stupor and somnolency, from which
he is only roused by another fit of delirium. Approach
to such an animal is attended with considerable danger ;
for, now and then, while attempts are making to ad-
minister medicine to him, he will throw his head up,
be suddenly seized with vertigo, rear up, reel round
upon his hind legs, and precipitate backward with
such dreadful force that those in attendance conclude
every such fall must prove his destruction. As ho
grows worse, instead of lying in a state of insensibility,
after the fall, he will pant and perspire and perhaps
foam at the mouth with pain ; convulsions seize him from
time to time, and he will often survive in this dreadful
agony for many hours, unable or unwilling to rise
again, until death put an end to sufferings which defy
all human interference.

The state of the brain in staggers, generally speaking,
appears to be, in the beginning, that of simple conges-
tion or unequal distribution of blood ; this, if it be
not timely diverted, runs into actual inflammation, of
which many and various are the consecutive effects : the
first of these morbid states would appear to be de-
noted by the stupor and somnolency present ; the ap-
proach of the last seems to be manifested by the rising
of the pulse and the indications of delirium. In most
of the heads I have examined, I have found vascular

438 On Staggers.

distention of the membranes, minute bloody specks
upon the divided surfaces of the cerebrum, turgidity of
the plexus choroides, and more water than natural
within the lateral ventricles. In one instance I could
detect nothing unusual in the brain but a remarkable
yellowness of the substance of the cerebellum: this
horse also had considerable disease of the liver; the
gland was very dark colored, nearly black in places,
and its texture had become so soft that the finger easily
made way through its substance. Professor Cole-
man folates one case in his lectures in which no other
morbid appearance could be discovered but an intense
inflammation, approaching gangrene, of the Schneide-
rian membrane, not only throughout the cavities of the
nostrils, but also extending over the frontal and max-
illary sinuses ; and another case, in which a tumor was
found within one of the lateral ventricles.

Soon after my father entered the service of the Ord-
nance, at Woolwich, it became the custom there to
turn horses, who had become low in condition and stale
upon their legs from work, into the marshes to recruit
their strength. During the months of July, August,
and September, no case was more common than an at-
tack of staggers among these horses ; which my father
attributed to the luxuriant pasture they were suddenly
turned into, (which invariably loaded them with fat and
consequently plethorised their systems,) combined with
the dependent posture of the head, and the sultry heat
they were exposed to in marshes destitute of places for
shade : this practical observation made on a laro-e
scale throws considerable light upon what I have ad-
vanced on the etiology of staggers.

The horses above alluded to were speedily relieved.

On Staggers. 439

providing they were timely attended to, by the free
and immediate use of the lancet : indeed, every com-
mon farrier knows that you must bleed freely in stag-
gers, but there are none of them, I will venture to
say, and but few veterinarians, I am apprehensive,
who carry phlebotomy to the extent they might and
ought. One would think, from our knowledge of the
distribution of bloodvessels, that we could not draw
blood from a more favorable source than the jugular
vein ; it is my duty however to remark here, that
some practitioners give the decided preference to the
temporal artery. In a late communication from my
friend Mr. Cordeaux, he informs me, ** that he has
seen eminently good effects from bleeding from the
temporal artery in six or seven instances ; and that
two cases, which were considered as hopeless, after se-
veral ineffectual bleedings from the j ugulars, recovered,
he verily believes, from an accident that befel them
during the night, by which the pins were torn from
their temples and considerable quantities of blood es-
caped and were found next morning in the manger."
This last remark of Mr. Cordeaux's corroborates
the advice I have given of taking care to bleed pro-
fusely : most of these subjects will bear to lose six or
eight, and some even ten quarts of blood. In my
own practice however, in cases of urgency, in which
congestion has existed for some considerable time, and
the circulation has become tardy and oppressed, I have
at times found the jugular veins to be the only sources
from which I could draw blood in any quantity, a
circumstance that invariably renders the prognosis
highly unfavorable. The next consideration is purga-
tion. The common saying is, ^' purge a horse with

440 On Staggers.

staggers and you cure liim ;" and there is much truth in
the observation, for we know that hardly any one thinks
of purging before he has bled the animal, so that the
purge is acting under the most fiavorable circumstances.
I would give 5fs. or 9ij. of the pulvis crotoiiis in com-
bination with the same quantity of calomel, and I
should prefer the form of a drink to that of bolus.
The decoction of aloes however is little or not inferior,
that I am aware of. Promote their action by aloetic
enemae, taking special care that the rectum is first
cleared of its contents by manual operation. I would
follow up the first dose of purgative medicine by
diminished doses exhibited every twelve hours, until
copious purgation was established : there is little dan-
ger of super-purgation under such circumstances. In
the intervals, between the repetition of the purges, hel-
lebore should be administered every six hours in doses
of ^fs. or even 5]. providing the first quantity make
no impression : nothing, bleeding excepted, operates
more effectually in diminishing the force and celerity
of the current of blood to the head than the excite-
ment of nausea at stomach. Having by these means
sensibly weakened the impulse of the carotid circula-
tion, the head should be shorn and blisters applied
over the forehead, occiput, and temples; and they
should be renewed every six hours until vesication be
abundantly produced. The legs are generally very
cold in the lethargic stage, and then there can be no
objection to stimulation of them by applications of
turpentine, mustard, cantharides, or simply hot water ;
but I should not pursue this practice, did they re-
main cold, in the phrenetic stages : I prefer simpler
means, such as friction, &.c. which may be practised

On Strangles. 441

without fear of increasing the vascular excitement.
We are recommended by some to insert a rowel under
the jaw : rowels and setons too are not likely to be
productive of harm in the acute stage of phrenitis,
for neither of them will take any effect unless the
pulse sink ; but, if we would have recourse at once-
to effectual measures, these harmless means may be
postponed until the violence of the inllammation has
been subdued.

On Strangles.

"The strangles," says Gibson, has been compared
by the French and other foreign writers to the small-
pox in men because to both the young are more in-
cident, and because the strangles " never seizes horses
but once. But however that may be, it is certain the
strangles is a critical swelling, which when it breaks
and imposthumates, discharges somewhat obnoxious to
the constitutions of young horses, by which they arc
usually rendered more healthful than they were be-
fore." Bracken, commenting on this comparison,
(of Soleysel's,) satirically remarks, ''that, on
strict scrutiny, it will be found only flourishing upon
the matter, as is too commonly the practice with long-
winded authors. For, the strangles are produced from
catching cold, or from what we tei^i perspiration ob-
structed." Taplin, who lashes the pathology of
SoLEYSEL and Gibson, in his usual unsparing
style, tells us that strangles consists in the elimination
from the system of an " accumulation of impurities"
imbibed with the food in colthood ; and that this
" lurking viscidity is roused from its latent communi-
cation with the juices, and called into action by

442 On Strangles.

bringing the frame into sudden exertions and con-
stant exercise," — for, experience demonstrates, he con-
tinues, that twenty horses have this distemper after
being taken to work, to every one attacked with it"
in colthood. White manifests unpardonable igno-
rance of the nature of strangles when he begins his
description with, "This disease consists in an inflamma-
tion of the membrane of the throat and nose, and S7celling
of the glands under the throat." Professor Peall
leaves the question of its nature and tendency unagi-
tated. Mr. Blaine is the only writer, I have perused,
who has offered any thing in the shape of theory con-
sistent with the present state of our pathology. He
says, independently of its attacking horses about the
adult period, and only once, it may be characterised
as a catarrhal affection, accompanied with a specific
phlegmonous inflammation of the cellular substance
in and around the parotid and submaxillary glands,
tending in most instances to abscess."

About the adult period of life, between the fourth
and fifth years, and more particularly at the season
when catarrhal and pneumonic affections are most
prevalent, horses in general become the subjects of a
diffused swelling under the jaw which in farriers' cant
is called strangles. This tumor consists in a circum-
scribed inflammation, having all the characters of sim-
ple phlegmon, attacking the subcutaneous cellular
substance included between the branches of the jaw,
which in consequence becomes gradually filled and
distended with effusions of lymphy and serous matters,
acquires a firm and solid feel, tenderness on pressure,
and a sense of unnatural heat. This commonly pro-
ceeds to suppuration, ending, to all appearances, in a

On Strangles. 443

common submaxillary abscess. Now this, and this
alone, constitutes strangles : there are in books a va-
riety of other symptoms described, but they are all
concomitant or accidental, none, but this, being, pro-
perly speaking, essential to its existence. The usual
concomitants are — membranous inflammation, giving
rise to soreness about the throat, reddening and dis-
charge at the nose, and perhaps cough ; tumefaction
of the salivary glands, producing pain and difficulty
in deglutition ; and, lastly, some slight febrile com-
motion of system. Cynanche trachealis, pneumo-
nia, and, some say, glanders, may supervene upon
strangles.

By those who consider it necessary to expatiate
upon the diagnosis of strangles and glanders, the
diffusive nature of the submaxillary swelling in one,
and its circumscribed limits and adhesion to the bone
in the other, are generally laid much stress upon ; but,
really, this of itself is a very insufficient and even a
dangerous guide ; for, I have known many cases in
which strangles has approached so gradually and in-
sidiously, appearing to begin in swelling of the sub-
maxillary salivary glands, that upon this naked and
unnatural distinction the case might have been pro-
nounced to be glanders. The true and safe diagnosis,
so far as relates abstractedly to the submaxillary tumor,
is to wait a while, and the case will soon manifest
itself, if it be strangles.

To what this affection, one to which horses appear
to be by nature subject at one time or other of their
life, is attributable, I will not pretend to conjecture ;
and I acknowledge myself equally in the dark in re-
o-ard to what or any salubrious change it may effect

444 On Strangles.

in the system. All I know about its specific character
consists in the universality of its attack, the age of
the subject, and the slight accompanying febrile de-
rano-ement. Even in these— its peculiar characters,
however, it manifests great irregularity: Bracken
says, " although I have bred several colts myself, not
one to my remembrance ever had the strangles, and
this I attributed to their being kept well and warm
in winter." A colt bred by my father had the disease
at six months' old; and Mr. Coward informs me,
that he has seen the disease three months after birth.
In some cases, the attendant fever is so slight that
it is hardly discoverable ; and in others there does not
appear to be any fever at all. So that, I repeat, even
the peculiarities, or specific characters of this disease,
discover much irregularity.

Taplin says, in concluding his account of stran-
gles, " it is necesary to be remarked, and well remem-
bered, that the disease we are now treating of, by
neglect and inattention, sometimes degenerates into
a confirmed glanders and this, 1 believe, still to be
the prevailing opinion : the inquiry would involve us
in the latter subject, and therefore I shall postpone it.
It is now quite time, I think, that the notions of in-
fection or contagion being a part of the nature of
strangles were dropped : at least, everyday occur-
rences, and some few experiments that have been
made, tend to disprove these unqualified vulgar pre-
judices.

The treatment of an ordinaiy case of strangles is
an affair of peculiar simplicity. The common notion
is, that, unless an abscess form and be evacuated, the
animal docs not derive that constitutional benefit

On Strangles. 445
which nature intended him : this is one of those vulo-ar
chimeras however that seems not, upon any rational
grounds, to be deserving of more attention in practice
than is requisite to appease those who are determined
to follow the humoral or farriers' pathology. I per-
haps may be censured by the profession for what I
am going to observe, but I cannot, with justice to
my own experience, make a display of what may be
really set forth in so few words ; viz. that all the treat-
ment a common case of strangles requires is a blister
to promote the suppurative action — if I may be allow-
ed the expression, to spur nature onward to the end
of the process. Professor Peall has been at con-
siderable pains to show the inutility of poultices and
fomentations; but I really have neither space nor
inclination to follow him in so unprofitable an exposi-
tion. Suffice it to say, that they are troublesome in
their application, comparatively of little effect, and
quite unnecessary. Steaming the nostrils with scalded
bran in a nose-bag is even prejudicial : it aggravates,
by its suffocating tendency, that soreness of throat
and difficulty of breathing which it is generally in-
tended to relieve. Those who may feel disappointed with
this simple view of the case, will find ample satisfac-
tion among the digestive ointments and alterative balls
and other farragos recommended by White. Catar-
rhal, pneumonic, or other accidental symptoms, must
be met by appropriate measures. In regard to opening
the abscess, and the general management of the case,
I must refer the student to the account of abscess given
heretofore*.

* Part I. Ler.ttire ix, " Diseases of the Cellular Membrane-'*

LECTURE LXXVII.

On Glanders and Farcy.

AViTHOUT taking up time and (what is here of
more value to us) space to make any inquiry into the
origin and propriety of these vulgar but well-under-
stood appellations for two of our most important dis-
eases, I shall forthwith enter upon this highly inter-
esting subject with an exposition of the doctrine I have
carried about with me from my pupillage, for which
I am chiefly indebted to the researches of the present
Professor of the Veterinary College. It would have
come with many advantages from the Professor's
pen which I am apprehensive it will now be deprived
of ; but, situated as I am at present, my duty requires
me to put it into the form of a lecture ; and I shall
use my endeavours to do so, as near as I can, after
the manner in which it was orally conveyed to me.

Professor Coleman makes a division of glanders
into two forms or species: acute and chronic. That
species is acute, which, like other acute diseases,
proceeds regularly through its course, and ends in
death ; that chronic, which, so long as it remains
so, will not destroy the animal. This is illustrated

On Glanders and Farcy. 447

by what happens in chancre and buboe, and (venereal)
gonorrhcea ; the former require the administration of tlie
specific, the latter will in the course of time cease
spontaneously.

Acute Glanders may be defined to be, a specific
inflammation and ulceration of the Schneiderian mem-
brane, more particularly of that part of it covering
the septum : that appearing to possess a higher degree
of susceptibility. It is generally attended with tume-
faction of the submaxillary lymphatic glands : which
tumor is simply the consequence of irritation.

The disease has been long known to be contagious
— to be communicable through the medium of conta-
minated stables, and by inoculation ; hence it has
been concluded that it had no other origin but con-
tagion. Most physiologists indeed have supposed that
cutaneous diseases could not arise from any other cause ;
and there are certainly some animal poisons whose oper-
ation appears to favor this hypothesis ; but, in prose-
cuting our investigations, it would seem that every
such poison is governed in its operation by certain
laws peculiar to itself : as different medicines produce
different effects, so the different poisons of contagious
diseases appear to possess peculiar properties, though
the diseases themselves all in common admit of propa-
gation by contagion. There are several diseases affect-
ing the human subject, that, according to general opi-
nion, can only be generated by contagion ; such are sy-
phylis, cow-pox, small-pox, measles, and hooping-cough.
When a person has contracted any one of these dis-
eases, it is said that he has been in the vicinity of
contagion or infection ; and it may be impossible to
prove, beyond all suspicion, the contrary ; but, what

I

f'448 On C Zanders and Farcy.

tv^s it that first bred these disorders ? Not contagion ;
but a combination of certain causes; and, being once
engendered, they became contagious. We have ex-
amples of this in jail and ship fevers, and in dysentery :
rihese, once generated, become contagious ; notwitli-
"ataiiding no such cause could possibly give them ori-
grn. Itch, the Professor believes> is often produced
'm the absence of contagion : it is bred in persoaral
unclcanliness. Why, then, may not ; hooping-cough,
small-pox, &c. arise spontaneously, 2. e. from the sanip
causes which originally produced them ? Those who are
most conversant in the habits and diseases of horses,
mow know, that glanders, although demonstrably con-
^tagious, much more frequently arises from other
caxises : it is a disease that rarely or never spreacfe
among horses at pasture, though a glandered subject
miay have been grazing among them; for, we learn
tfrom experiment, that, although the disease is cooi-
f municable by contact, the poisonous matter must be
applied to a part bare of hair, and that, even tlren,
■'the chances are in favor of the animal escaping in-
ffection unless the part have previously been, or happ^
to be. in the act, abraded. in lO /s* . , . :-..jod*fi

r There are two casual experime'titatrmalts "By y/kftt^
practitioners, in investigating this mibject, have stif-
fered their judgment to be misled, and thence hav^
.dome to erroneous conclusions. The one is, that, be-
fCftuse a horse has been subjected without effect to in-
:.QCulation, ergo, the animal from whom the matter of
-jftf-ection was taken/ cannot be glandered ; the other,
-ihat/ because the former became glandered, ergo,
^tl\e latter must of necessity have tire disease. There
-M<^:r-two circumstances absolutely and indispensably

On Cjlunden and Farcy. 449

necessary for the production of a disease by conta-
gion : — the application of the poison, and the suscep-
tibility of the animal or part to which it is applied.
You may inoculate without success from insuscepti-
bility of the inoculated subject, on the same principle
that you may administer the same doses of aloes to
two horses, and effect violent purgation in one, but
make no impression upon the other. It is by no
means uncommon to see persons inoculated for cow-
pox and small-pox without effect : the explanation
of which is, that they are not susceptible of that de-\
gree of poisonous excitation at that particular period.
Aijain, it has been aroued that a disease could not be
glanders from which a horse recovered, even though it
showed every characteristic outward sign of glanders.
But the very groundwork of this position is untenable :
the Professor has seen (and so have I) several cases of
spontaneous cure from chronic glanders ; and evidence
may be brought forward of recovery even from acute
glanders combined with farcy.

So far from contagion being the common cause of
glanders, the Professor estimates that not one horse in
a thousand, or even in ten thousand, so receives the dis-
ease. The poison of glanders is bred and diffused in
an atmosphere rendered impure by repeated respiration,
and by gaseous impregnations from the dung, urine,
and perspiration, emitted in hot and foul stables. No
vital being, neither animal nor vegetable, can maintain
life in the total absence of pure air ; and, according as
an animal is from nature habituated to purity, so, gene-
rally speaking, it would seem that he suffers from at-
mospherical contamination. There are several sorts of
vegetables that cannot be grown (or at least to perfec-

PART III. 2 G

450 On Glanders and Fanu/.

tioii) in the vicinity of London, in consequence, we
believe, of the impurities continually floating m the
atmosphere ; whereas, there are animals (such are rats
and mice, and we may add bots) who enjoy health
in the most confined and noisome situations. Man can
withstand a contaminated or poisonous atmosphere, it
would appear from his habits, much better than the
horse : we join house to house, form villages, towns, and
large cities ; and we livetlius crowded together with seem-
ing iunocuousness : still, to obtain specimens of well-
grovm forms and robust health, we must go into the coun-
try and select them from among the husbandmen ; for in
l^ge and populous towns, instances are always present-
^ig themselves of rickets, scrofula, consumption, &c. &c.

,The horse is an animal destined by nature to breathe
an atmosphere of the purest kind ; in proof of the sa-
lubrity of which to him, suffer him to remain in his
native fields, and he will livelong and ail nothing. But,
bring him once into a state of domesticity, place him in
a confined situation, in which he is compelled to breathe
air that has been already respired, not only by himself
but perhaps by other horses also, air impregnated with
the exhalations from the urine, dung, and perspiration,
and you sacrifice him a victim to malignant and fatal
maladies. And none of our domestic animals, no more
than horses, can tolerate this with impunity. If poultry
are kept in a confined place, they breed what is called
the pip, which is a very destructive disease among thera.
^pgs, under similar circumstances, engender the husk,
a species of pulmonaiy phthisis. Even plants, unless
they are occasionally supplied with fresh and pure air,
will wither away and die in our greenhouses. These
morbid consequences ^jj^e npt from any deficiency in

On Glanders and Farci/. 451

the vital or oxygenous part of the air ; tor, it is found
by experiment, that there is proportionably as much
oxygen in the atmosphere of the closest alley in Lon-
don as in that which encompasses the hills of Highgate :
no ! these deleterious etfects are ascribable solely to the
animal poisons contained in the atmosphere, which are
not only inhaled with the breath, but probably taken in
with the food also ; be that as it may, however, through
one or both of these channels the poison becomes ab-
sorbed into the system, corrupts the whole circulating
mass, and breaks out in local forms in various suscep-
tible parts of the body. Tlierefore it is, that, in the
degree in which a stable is foul and heated, from want
of ventilation, we find its inhabitants the subjects of
glanders, farcy, opthalmia, &c. we seldom receive these
cases from gentlemen's stables, because in general they
are well-constructed, and kept clean, and do not con-
tain many horses ; but in collieries, breweries, post-
houses, coach establishments, &c. where the stables are
filthy from the dung and urine which stagnate in cavi-
ties in the pavement, for want of proper sewers to carry
them off, and where the men are suffered to add to the
mischief by plugging up every air-crevice they can find,
we are continually witnessing the ravages of these very
formidable diseases. Farmers' stables, though no bet-
ter or even worse in their construction, do not appear
to turn out so many glandered subjects; a fact that ad-
mits of reconciliation with what has been advanced,
from the circumstance of their stables being in general
very capacious, and many of them in too ruinous a
state to admit of exclusion of the external air. The
Professor was first led to adopt this notion of the spon-
taneous origin of glanders and farcy from an occurrence

2 G 2

On Glanders and Farcy.

in our cavalry service which came to his knowledge.
Many years ago (I beUeve about 1796) there was an ex-
tensive encampment upon Dover heights, from which
the horses could not be removed until the autumnal
season was far advanced, in consequence of the stables
intended for their reception not being in a state of readi-
ness : now, the stables were newly erected ones, not-
withstanding which, great numbers of these horses,
though previously in perfect health, soon after entering
them became diseased ; the greater proportion contract-
ed grease, but several were attacked with glanders and
farcy. He has since also received peculiarly satisfac-
tory evidence of this in two memorable instances, in
which stables which were hot and foul, and had from
time to time turned out several glandered horses, were
rendered equally salubrious with others adjoining them
by proper ventilation and attention to cleanliness.

By this time we shall have received some striking
illustrations af what was advanced in the outset, that
every animal poison is regulated in its operation by its
own peculiar laws : were it not, most wisely, so orr
dained, the whole animal creation must long before now
have been exterminated, If man had been susceptible
of contracting disease from horses, oxen, hogs, sheep,
dogs, &c. and these animals, in their turn, could have
taken human disorders, all must have lived only to act
their dreadful parts in the work of universal de-
vastation. /J
We now come to the relation of that celebrated ex-
periment of the Professor's, by which, not only the
contagious, but the constitutional nature of glanders
is proved beyond all doubt and idle speculation — that
experiment which goes to disprove the assumption of

Oil Glanders and Farcy. 453

Mr. Hunter, that the blood itself was never diseased.
Of a horse affected with acute glanders, the Professor
laid bare the carotid artery and jugular vein of the
same side, and around each vessel placed a ligature.
A pipe, furnished with a stop-cock, was then inserted
and fastened into the artery ; which was made to com-
municate, through the medium of a tube (a ureter, I
believe) with another pipe introduced into the jugular
vein of an ass : this animal having been previously bled
until he fell from exhaustion. In this manner, blood
was conducted from the artery of the horse into the
vein of the ass until the latter showed every sign
of perfect resuscitation. A circumstance occurred how-
ever in the revival of the ass, which, though it did
not affect the issue of the experiment, may serve as a.
warning to future experimentalists ; and that was, that,
in consequence, it was thought, of transfusing more
blood than was requisite, the ass appeared to be puffed
out or swollen all over the body ; this however was re-
lieved in the course of four or five days, in which time
the animal became glandered in a most violent degrees,
in confirmation of this, other asses were inoculated
from this one, and they all unexceptionably shared the
same fate. The loss of blood sustained by the horse
tvas not sufficient to take away life.
^' Acute glanders, as was said before, consists in a sp^
<^fic inflammation and ulceration of the membrane lining
the nose ; by specific is meant, an inflammation not at-
tended with the usual phenomena. If the inflamma-
tion could be as well recognised by any characteristic
appearance as the ulceration is, then the horse ought to
be pronounced glandered prior to the supervention of the
ulcerative stage : to this there are analogous instances
in the human subject. No surgeon decides on a case

454

On Glanders and Farcy.

of syphylis before chancre makes its appearance, or on
small-pox until pustules have formed. We may safely
lay claim to two discoveries respecting these diseases.
One is, that the whole mass of blood has been
found to be contaminated. The other is, that glan-
ders and farcy may be, and are commonly, produced
without the agency of contagion. Mr. Hunter
concluded that the blood was never in itself dis-
eased because he could inoculate with it in small-pox
and syphylis without infecting the subject ; whereas,
if he made use of lymph, he produced the disease.
This is no proof however that the blood contains no
morbific matter ; for the poison mixed with it may be,
as we now know it to be, in too dilated a state to take
any effect ; though, in the purulent discharge, it ap-
pears to exist in a concentrated form. On the same
principle, a person may drink a tea-cupful out of a
pailful of water containing a certain quantity of araertid
with impunity ; but, should he take a quart or a gallon
of the same fluid, he may probably experience from it
deleterious effects. Aloes itself is a poison exhibited
in large doses. Another proof of the blood being dis~
eased, is, that syphylitic infection will frequently
create disease in the throat : how could the poison get
there but through the medium of absorption and circu-
lation ? Be this explicable however as it may, we hav^
proved the fact beyond all doubt and dispute by thet
test of direct experiment. ne uiv

Glanders is not so prevalent in the summer as in the
winter season ; and it has, in several instances, been
known to be epizootic, particularly when horses brought
from camp or other external situations have been return-
ed into warm and unventilated quarters. If precautions
were taken to properly ventilate stables, the disease

On Glanders and Farcy. 465

might be altogether eradicated, lu further proof of
the disease originating without contagion, we have in-
stances of glanders breaking out among horses that
have been embarked in a perfectly healthy condition on
board of ships entirely new. In the expedition to Qui-
beron, the horses had not been long on board of the
transports before it became necessary to shut down the
hatchways : the consequences of this were, that the
horses were almost suffocated with heat, and that al-
most all of them disembarked either glandered or far-
cied. The malady which broke out among the men
engaged in the Walchren expedition, attacked almost
all of them, hence it was considered to be a contagious|
disease ; afterwards however it proved not to be, nor
was this assumption required to explain its endemic cha-.
ra^oter, for they all (if the expression may be allowed)
ate it, they all drank it, and they all breathed it. It ^
for want of reflection upon these points that people are^
so often differing about the contagious and non-conta-
gious nature of diseases. It has been observed, that
glanders is mostly present where grease is prevalent j
indeed, this fact led Sainbel to say, that grease was
a cause of glanders: but, in truth, it is no more a
cause than dung and urine are causes ; it is simply
operating as another source of atmospherical impurity.
Under such circumstances, the fetor of grease will pre-^
dominate, as the stench of a goat will, over the efflur
via arising from the excretions and secretions ; and it
was the observance of this fact probably that gave
origin to the vulgar notion of the salutary influence of
goats kept in stables. i
; The acute glanders is the same disease, in regard to
the nature of the poison, as farcy and chronic glanders ;
the Professor however is not so confirmed in his opinion

456 On Glanders aiid Farci^J

concerning the affinity of the last as he is in respect to
farcy- Acute glanders hardly ever proves fatal without
farcy making its appearance before death ; on the other
hand, farcy rarely or never of itself puts an end to life, it
being superseded commonly by acute, sometimes by chro-
nic glanders. Independently, however, of these prac-*
tical observations, we have shown their essential iden-
tity by direct experiment : we have produced farcy by
inoculation with the poison of acute glanders ; and
acute glanders by inoculation with the matter of farcy :
we do not always succeed, it is true, but one case proves
as much as a thousand. ^; .a^j-in^o j:^iLki.i}ci^ uui ajuu*
i Chronic Glanders commonly affects but one side
(Df the head ; if, therefore, a discharge makes its apr
^arance from one nostril alone, that of itself is strong
presumptive evidence of the presence of this disease.
This partial flux cannot come from the lungs, for, if it
did, the other nostril would discharge too ; it must
have its issue from some part anterior to the larynx,
consequently it can have no other source but the mem-
brane of the nose or that portion of it lining the si-
nuses. Should it come from the nose, the membrane,
most likely, will have a redder aspect upon that side
of the septum than upon the opposite, or there may
be a disposition to, or actual, ulceration. If the nasal
discharge is considerable, and, at the same time, the
animal to all appearances is in the enjoyment of good
constitutional health, that is a circumstance which
should serve to strengthen your suspicions: people
cannot conceive how it is a horse can have glanders so
long as he eats and drinks and does his work like one
in perfect health ; this very fact, however, I repeat,
is corroborative of an unfavorable prognosi^^ v f^nother
circumstance to be attended to, is, that the nasal flux

Ou Glanders and Farcy ^ 4S3^

has little or no fetor : ofFensiveiiess of breath is pietty
certain evidence that this disease is not present ; not
but what the two may exist in the same subject, but,
fetid breath commonly proceeding from the lungs,
and this chronic discharge coming from the sinuses of
the head, the one is not in any way necessarily conn
nected with the other. In glanders, the nostrils are
contracted and gummed with inspissated discharge;
but the flux is not ofi'ensive, or, at least, to the same
degree as pulmonaiy fetor is. Again, in glanders^
generally speaking, there is on the same side from
which the discharge comes, a defined swelling of the
submaxillary lymphatic glands, which is attached
olosely and immoveably to the side of the jaw : if St
^^.ac tumor of considerable size, one that is diffuse4
and extends inwardly, or one that is very moveabla
nnder the fingers, most likely it is not lymphatic, and
therefore not connected with this disease. So far as
the Professor's observation has gone, no such glandu^
lar swelling happens in common inflammation. In
chronic glanders, then, the general health, appetite^
spirits, &c. remain unimpaired ; there is simply a dis-
charge from one nostril, which is unaccompanied by
fetor, and a circumscribed immoveable tumor under
the jaw on the same side. In some cases, however,
ihe flax comes from both nostrils ; here, commonly^
bath sets of glands are tumefied, the nature of which
swellings will serve to direct the diagnosis ; in addition
to which, most probably, the animal's health continues
good, and the discharge is not offensive. But, if
-cough is present with such a discharge, the sab»-
maxillary tumefaction uniformly diffused between the
sides of the jaw, and there are feverish symptOBw

I

458 On Glanders and Farcy.

and evident impairment of the general health, the
lungs are probably in this case the seat of disease.
Still, in order that we may be certain about the ex-
istence of chronic glanders, we have no occasion to
implicitly rely even upon these signs ; for we may at
once decide the point by the test of practical investi-
gation. We have only to perforate (with a spill-gim-
blet) the frontal sinuses, and inject some clean tepid
water into them : should the sinuses be healthy inte-
riorly, the fluid will run from the nose either limpid,
as it was thrown in, or merely be tinged with blood ;
whereas, in a case of disease there, the water will
carry down with it the matter lodged in the cavities.
It is not uncommon, in this disease, to obseve a horse
discharging profusely for several days and then sud-
denly cease running altogether : this arises either from
inspissation of the matter collected, or from the effusion
of adhesive matter, within the sinus, which settles at
the bottom of the cavity and plugs up the aperture by
which it communicates with the chamber of the nose.
During the interval of suspension no sign of disease
remains but the submaxillary tumefaction ; there is no
discharge, and consequently there can be no source of
contagion: but, the collection of matter continually
augmenting, at length the plug is forced out, and the
flux returns with more virulence than ever. In Smith-
field, it used to be a common clieat to sell a horse hav-
ing this disease for a sound one, the trick consisting in
stopping up the nostril of the affected side with a piece
of sponge, which, of course, received and imbibed the
discharge.

Though we have no specific remedy for chronic glan-
ders, no more than we have for acute, the Professor

I

On Glanders and Farci/. 469

has seen more cases of recovery from this than from
the latter disease. When the discharge early in this
affection becomes profuse, and continues long so, it
will end, every now and then, in a spontaneous cure,
as is the case so often with gonorrhoea ; at other times,
the flux will persist and run for years, and the horse,
so long as the disease remains chronic, maintain his full
health . Many horses of this description are to be found,
in various parts of the country, working in road -wag-
gons, brick-carts, agricultural machines, &c. &c. ne-
vertheless, the disease is not only incurable by art, but
is contagious ; the matter emitted from the nose has
the property of propagating by contact either acute
glanders or farcy, or even both. ' ^'

Farcy affords, of all three affections, the most coni-^'
elusive evidence of the production of the poison in the
absence of contagion. It may be defined to be, an
inflammation and suppuration of the superficial order
of absorbents : it does not affect the deep-seated ordet
— they do not appear to be susceptible of the irritation.
This fact is not more extraordinary than many analo-
gous ones to be found in human medicine, such is the
case in respect to itch, small-pox, measles, gout, 8ic.
itch does not disease the stomach or bowels, gout is
not a cutaneous malady : certain parts are liable to
certain diseases, and the skin of the horse, as well as
that of man, has its peculiar aflPections, among which
we may rank mange, grease, various eruptions, and
farcy. The extraordinary circumstance connected with
the history of farcy, is, that, though it is a contagious
disease, it is rarely or never generated by contagion ;
indeed, the Professor even doubts the fact, though not
the possibility, of its ever, under ordinary circumstances,

4G0 On Glanders and Farcy.

taking its rise from contagion. For, in order to cdrn-'
municate farcy, it would be necessary that the matter
from the nose should come into actual contact with
some bare or abraded part of the skin ; and this, when
we come to consider how uniformly the skin is covered
with hair, and the mode in which we confine and stall
our horses in this country, is next to impossible in the
stable, and is very far from being likely to happen even
at grass. There would be greatly more chance of glan-
ders being communicated in this manner; for, as the
horse is an animal that takes cognizance of every thing
by his nose, one subject might besmear the pannels or
walls of the stable with the poisonous matter and ano-
ther sniff it off. With respect to one farcied horse com-
municating the disease to another, we may be very po-
sitive in refusing credence to this ; indeed, one might go
here so far as absolutely to deny everything but the in-
terference of art. In fine, where there is one case of
farcy that can be satisfactorily traced to contagion, the*
Professor reckons there are a thousand in which its
origin ia spontaneous, or in which it is a concomitant
6i glanders. In inoculating for farcy, simple abrasion
is all that is necessary ; indeed, should the puncture
with the lancet be made so deep as to penetrate through
tfefe skin, the probability is that glanders, instead oF
farcy, will be produced.

' No part of the body can be said to be exempt frohi
ftftrcy, though it shows a predilection for those places
where the skin is thinnest, and appears in situations re-
mote from the heart : its common seat is the inside of
the thigh ; but we very often find it upon the inner parts
of the arms and upon the breast, also along the neck/
and upon the cheeks and lips, in which last case greater

On Glanders and Farcy. 4f»l

uppi ehensions are always to be entertained of the super-
vention of glanders. Occasionally, it commences its
attack upon the body. The ordinary appearances or
signs of farcy are — corded swellings in the skin, follow-
ing the course of the superficial veins, and traceable
into lymphatic glands, either in the groin or breast, or
under the jaw, which, as well as the tumefied absorb-
ents, are hotter than the surrounding skin, and ten-s
der on compression. After a time, these cords assume
^ knotted appearance ; regular chains of knots or lumps
are formed in the skin showing most distinctly the course
taken by the superficial absorbents : these knots ar^
what farriers have denominated farcy-buds. When first
formed, they consist of effusions of adhesive matter j
but, as the disease advances, they gradually take on a
suppurative action, the progress of which change is de-
noted in them by their growing softer, hotter, and great-
ly more tender to the touch. At length, abscesses are
produced : these burst, and the limb or part affected be-
comes lined with a chain of small, circular, foul ulcera-
tions. The characteristic knotted tumefaction of the abn
sorbents is attributable to the intercepting valves, parts<
which do not seem to be susceptible of farcied irrita-
tion : for, if one of these diseased vessels be examined,
perfectly sound partitions of membrane will be found
between the knots, which cannot be any thing else
but the valves. It often happens, however, that the
buds, instead of undergoing an inflammatory process,;!
degenerate into hard lumps, having but httle heat or?
sensitiveness, which ultimately become converted into
schirrous substances ; in which state you may cut or
bum them without the animal evincing much pain
or uneasiness,,.^^rj^j)^rhaps seeming consciousness at

462 On Glanders and Farcy.

all of what is doing : so void are they of sensation
when they have undergone this change.

There is a form of this disease which the farriers call
watery farcy , as if it was a distinct species; whereas,
the pathology of such cases appears to be, that so many
of the absorbents being unable from disease to perform
their functions, the result is oedema in combination
with farcy : these cases manifest a more fearful disposi-
tion than others to run into glanders.

Farcy may be said to have various terminations.
The most common of all sequels is that of glanders.
Cases ending in apparent health however are by no
means uncommon ; nay, cures are every day said to be
performed ; and, no doubt, there are many cases in
which perfect health is restored ; but the majority, the
Professor apprehends, are only instances of temporary
arrest or suspension of the disease ; for, in too many of
them, months, and even years, afterward, swellings
are discovered under the jaw, and the subjects ulti-
mately become the victims of acute glanders. The
fact of our seemingly being able to cure one disease, and
certainly not the other, would appear to operate against
the affinity of farcy and glanders : (venereal) gonor-
rhoea and chancre however furnish us with analogous
ca,ses in human medicine ; one will cure itself, the
other can only be eradicated by the exhibition of the
specific. At other times, these cases will end in gene-
ral thickening and induration of the affected parts ; the
skin covering the enlarged absorbents will become mor-
bidly thick, and grow callous to all ordinary stimuli ;
and, in this condition, the animal may enjoy, to every
appearance, good health for months, or even years:,
but, let it be remembered, that the seeds of glanders

Oh (Handers and tany.

463

are still probably lurking in the system, and only await-
ing the stimulus of re-action to break out again in some
visible and more destructive form, and carry the animal
to his destined fate ; as if it were to show us the radi-
cal inefficacy of our remedies, and the instability of
any remission, however long, we may obtain on such
dubious grounds. You may have acute and chronic
glanders and farcy in the same individual ; though it
never happens, I believe, that acute glanders or farcy
ends in chronic glanders.

. In incipient farcy, it is proper to inflame the skin co-
vering the affected absorbents by rubbing the blistering
infusion upon it, or by the employment of the actual
cautery — firing in the course of the corded sweUings t
these escharotic remedies destroy the cutaneous surface,
and, so far as regards the local affection, are likely to
excite healthful and restorative action. Unless there
be pus effused ; and then the system is most probably
infected, (by absorption of the matter) even should the
disease have been purely local in the first instance.
Here then, certainly, (and probably at all times and in
all cases) constitutional remedies should be resorted to.
That which in the Professor's opinion holds out the
most favorable prospect, is copper, either in the form of
the cupri sulphas or cupri acetas, which may be com-
bined with some terebinthinate : in its administration,
it is advisable to commence at once with large doses *,
and repeat them every one or two days, according as

* R CupriSulphat.Svj. — 3viij.^ oC R Cupri Acetat. 5j.

Terebinth. Vulg. 5ft. C g:^ Terebinth. Vulg. 3ft.
Farinae q. s. ut. f. Bol. j ^ (. Farinas q. s. ut. f. Bol.

or, the copper may be given in a state of solution, should the ball
occasion nausea and loss of appetite.

464 On Glanders and Farcy.

the stomach will bear the action of the metal. Exer-
cise, good air, full diet, and turning the subject loose
into a roomy box, are serviceable auxiliaries. — If ab-
scesses have already formed, apply the heated budding
iron to them singly, so as to burst them and destroy the
morbid secreting surface ; and, at the same time, cover
the parts with a liquid blister: by such measures, in
combination with the internal exhibition of either blue
or green vitriol, the Professor has seen the disease, in
many cases, to all appearances, subdued : any progno-
sis however draw n from such results should always be
properly guarded. When the sloughs have separated,
and open ulcers are exposed, they may be dressed daily
with a solution of copper, or alum, or zinc ; or the cau-
tery may be re-applied ; according as the case seems to
require.

With regard to remedies for glanders, either in its
acute or chronic form, the Professor has nothing to
offer. He has prescribed, by way of experiment,
almost or quite all the mineral and known vegetable
poisons : preparations of arsenic, antimony, copper,
zinc, mercury, &c. hellebore, aconitum, digitalis, hy-
oscyamus, cicuta, belladonna, &c. Sec. have been, in
various condemned subjects, internally administered ;
but all without any specific or curative effect on this
awful and obstinate malady.

10x3
»aool

V oi afl oa ,

LECTURE LXXVlll.

•OW Wrijf:) to

oi .d«B5a(h dili aS^'eiHTo;'

s^v*^. « ^laiuiers and tarcu continued.
.IkiifiTAqM d 'i. n - ; ;r -wot*!

N the past lecture I have endeavoured to convey a
knowledge of the doctrine propounded on these sub-
jects by Professor Coleman; I shall in this, my con-
cluding lecture, submit an exposition of that promul-
^gated on the same topics by Professor Dupuy, whose
celebrated work*, which was published in 1817, none
to our credit or judgment, remains to this day virtually
unknown in British veterinary medicine. This pro-
ceeding will render the doctrines of the highest British
and Continental authorities subsei"vient to reciprocal
'elucidation, and at the same time will afford an oppoi*>-
tiinity of drawing some comparison between their
jopinions. The facts and observations presented to us by
the French Professor are for the most part of a novel

* " De l'Affection Tuberculeuse, vulgairement appelee
morve, pulmonic, gourme, farcin, fausse gourme, pommeliere, phthisic
du singe, da chat, du chien, et des oiseaux doniestigties ; comparec a
Vaffection htjdatidtuxe ou pourriture. du mouton, du lapiu, du lievre, et
a la ladrerie du cochon. Par iNJ. Dupuy, Medecin-Veterinaire,
et Professor a I'Ecole Royale d'Economie Rurale et Veterinaire d'Al-
fort, Membre de la Societe Medicale d'Emnlation. A Pans, 1817."

PART III. 2 H

466 On Ghmders and Farcy.

and most interesting description, and many of the con-
clusions deduced from them such as are likely to prove
of considerable importance to us in our future practice.

The end proposed by M. Dupuy in this research
was to obtain correct pathological views from a multi-
tude of observations, both on the living and dead sub-
jects, extended to domestic animals in general ; and
with this view he commences his work with a rapid ex-
position of the different opinions of the most popular
French authors on the subject, not comprising those
however who are still living, and brings his historical
account to the following conclusion. " It is evident that
the ancient authors have not directed their researches to
determine the nature of glanders : they observed the
outward symptoms, the obvious signs of disease, and
they framed hypotheses, and theorized upon conjec-
tures ; not one of them has viewed it as an organic
lesion, nor suspected it to be so common as it actually
is. The moderns have nothing enriched their ideas ;
they have pursued the same tract : like those who have
preceeded them they have not sought for the source of the
evil ; their writings are really nothing but commenta-
ries ; they have developed, amplified, presented us in
other forms with what was written before.

I shall make a division of my labors on the glanders
of horses, generally considered," says M. Dupuy, " into
two parts. In the first, I shall view the tubercle as an
organized production, formed or developed at an indeter-
minate period ; after which it degenerates, deranging
the functions of the organ itself, as also those of the
economy in general. In the second, I shall show the
changes the tubercle undergoes ; and relate the phe-
nomena preceding, accompanying, and following its

On Glanders und Farci/ 467

degeneration and subsequent ulceration : towards the
end of this second period it is that we observe the most
striking derangements in the animal economy. These
derangements make more or less impression, influenced
by a multitude of circumstances connected with the
animal and its surrounding agents. In another place,
I shall develop the predisposing and determining causes.
My principal object being to point out the progress of
the tuberculous affection constituting glanders.

" FIRST DIVISION.

" The Tubercle forms and multiplies.
" The organized production we have named tubercle
is the product of a cause which to me appears unknown.
Nevertheless, it is under this unknown influence that its
component elements coalesce ; and to the same cause
must be ascribed the different material changes it un-
dergoes.

" The primitive tubercle is a little, firm, grey, hard
body, composed of a fine cellular tissue, in which is
deposited a substance that proves to be phosphate and
carbonate of lime : it is mostly inclosed in a small cyst,
appearing to be a production of the tissue in which it is
formed. — These incipient tubercles exist in small num-
bers, and interfere but little with the functions of the
affected part. — At thistirne, the animal enjoys a flou-
rishing state of health, and glanders is unknown to ex-
ist,— We next discover, without being able to assign
any satisfactory rationale for it, that the tubercles grow
more numerous : in which case they occasion a dis-
charo-e or flux, most commonly from one nostril : this
is regarded as catarrh or chronic defluxion, or, shpuld
the horse be young, as strangles." The space pf time

2 H 2

468 On Glanders and Farcy.

during: which the tubercles preserve this organization,
grow, and increase, (five or six years perhaps) consti-
tutes the first stage : during which they resemble so
many poppy seeds.

In the second stage, the tubercle grows soft— disor-
ganized, and degenerates and becomes converted into
an ulcer : this ulcerative degeneration is what has been
seized upon by Lafosse, Chabert, and other au-
thors, and made the basis of their divisions and dis-
tinctions of glanders.—" The ulcerations observed upon
the mucous membrane of the nose in the last period of
glanders, consequent upon the degeneration of the tu-
bercles, are insulated or united, grouped, or so near
one another that in meeting they disorganize a broad
patch of the Schneiderian membrane. These altera-
tions depend upon the variety of the tuberculous affec-
tion.

" The variety I shall name miliary is the one oftenest
met with. The degeneration of this variety of tubercles
converts them into little ulcerations, with thin edges,
unevenly excavated, resembling pin-holes; with this
difference however, that the hole made by a pin would
be deep and pointed, whereas these ulcerations are shal-
low and have indented edges. They are commonly re-
garded as erosions, often mistaken for the dilated ori-
fices of mucous follicles ; but, if they be examined
after the mucus in which they are sheathed has been
removed and the membrane has been cleansed with
water, they will be found to be so many little ulcers.
The membrane clothing the septum is frequently covered
with these exulcerations, and its surface in places
elevated. But they are superficial, penetrating merely
through some thin layers of the cellular tissue of the

On Glanders and Farcy. 469

membrane, thereby rendering its surface irregular, un-
even, and scabrous. Cocteris paribus, they exist in
greatest numbers over the large veins pervading the
septum. They are also found grouped within the dou-
bling forming the internal ala of the nostril, particu-
larly on the left side, following the course of the blood-
vessels, and upon the turbinated prominences and
their appendices.

" These tubercles, by interunion and simultaneous
ulceration, may produce a broad ulcerous patch, threat-
ening destruction to the parts beneath. Though for
a time the perichondrium preserves the cartilage, at
length it likewise degenerates, even should such a
change not be accelerated by the existence of tubercles
within its own proper tissue, of which I have received
numberless casual demonstrations. — Similar destruction
pervades the turbinated, frontal, and maxillary bones.
They grow puffy, swell in volume, and turn spongy ;
the surfaces of them forming the sinuses become covered
(internally) with spongy, unsubstantial, very porous
excrescenses ; and the bone is deprived of its earthy
composition : such are the different lesions met with in
horses who die or are destroyed from glanders.

" In this variety of the ulcerative decline, the mem-
brane bordering, even very close, upon the ulcerated
places preserves its organization. Prior attacks of in-
flammation, either of the acute or chronic type, may
also leave traces upon the membrane, which then be-
comes the seat of two perfectly distinct lesions ; of ul-
cerations resulting from the tuberculous affection, and
of a fibrous induration, radiated in the form of stars,
which is really the result of the consecutive chronic in-
flammation that has attacked the membrane at differ-

470 On Glanders and Farcy.

ent times, and converted it into a fibrous, white, fimi,
lardaceous tissue, bearinpi: great resemblance to schir-
rus.

It follows, then, from what has been said,
" ]st. That glanders is really a tuberculous affection.
" 2ndly. That it bears the closest analogy to phthisis
pulmonalis in the human subject.

"ddly. That the miliary variety is the most com-
mon.

'Stilly. That the left is the nostril ordinarily af-
fected.

" bthly. That the membrane lining the sinuses is
rarely found tuberculated or ulcerated.

" Qthly. That a glandered horse may contract a ma-
lady of a gangrenous nature.

" Itlily. That this gangrenous affection, which is
contagious and idiopathic, should be carefully distin-
guished from the true glanders.

" I hope to set this last proposition out of the reach
of doubt by some special cases I have to report of acute
glanders, which I take to be an angina gangrenosa or
analogous affection .

" I have also observed tubercles in other tissues be-
sides the nasal membrane, principally within the paren-
chyma of the lungs, within the lymphatic glands, cel-
lular membrane, skin, testicles, lining membrane of
the alimentary canal, &c.

" The lymphatic glands commonly diseased are the
sublingual (submaxillary) and the guttural, and the tu-
bercle is mostly the miliary. They first change color,
tumefy, and grow firm, and albugineous in appearance,
displaying, interiorly, dense, yellowish, encysted mili-
ary tubercles. I cannot determine how long the tuber-

On Glanders and Faicy. 471

cles continue in this first stage ; though I have ascer-
tained, that, once developed, they become insuscepti-
ble of resolution.

" Should glanders be complicated with a tuberculous
affection of the lungs, the animal coughs frequently ;
tires early; perspires freely; later, he loses his vigor
and energy ; grows washy, soft, and lazy ; becomes
subject to catarrh, weak eyes, cutaneous eruptions,
farcy, oedema, cracks, &c. At length the digestive
functions manifest disorder ; the animal has a re-
markable bloated aspect ; the cellular tissue is blown
up, as it were, and pits ; the conjunctiva is infiltiated ;
the caruncula lachrymalis discolored ; the eye has the
expression of that of a sheep suffering from rot ; the
gums are pallid ; and the under eyelid of the affected
side juts into a prominent circle or duplication. If
put to hard work, such horses rapidly decline in con-
dition ; and yet, should they be destroyed, fat is found
in abundance upon the belly, and about the heart. It
is at this period that the glanders becomes complicated
with farcy.

I cannot regard farcy buds in any other light but
as scrofulous tubercles. They become developed under
the same influences, possess the same organization, un-
dergo similar conversions, and decline in the same man-
ner as pulmonary tubercles. As for their frequent dege-
neration into cancer or carcinoma, cannot we attribute
that change to caustics or the actual cautery, which
are frequently applied to the buttons of farcy in a man-
ner at once inconsiderate and abusive in the extreme ? —
I shall conclude these considerations by observing, that
the glanders or phthisis of the nasal membrane will
turn, under some circumstances, into an affection of a

472

On Glanders and Farcy.

cancerous nature ; while, under other circumstances,
it becomes complicated with a disease analogous to the
typhus of horned cattle, and the conflu^it scab ( da-
veau confluent) of sheep, which proves very fatal in
combination with typhus.

" Farcy is often a local and an original affection.
Nevertheless, will any one pretend to draw an induction
from these facts to prove that it is a different disease
from glanders, and that it cannot originate from the
same cause, although farcy admits of being cured,
while glanders has resisted every means hitherto op-
posed to it ? This is not the first time that we have
heard of one variety of the same disease being curable,
and another not. Schirrus disappears without relapse
under many circumstances. And yet it is not so with
cancer, carcinoma, &c. These observations serve to
reconcile the contradictory accounts of veterinarians,
when we find one declaring that farcy is easily cured,
and another maintaining a directly opposite opinion.
The probability is, that they have been treating differ-'
ent varieties of the disease : in one case the farcy may
have been local ; in the other, constitutional."

M. DuPUY next observes, that the process of dege-
neration in the absorbent glands seems to proceed from
the circumferent parts to the centre ; the fact however
is hardly confirmed ; if it were, as he adds, " it would
form a remarkable particularity. One important con-
Bideration however is, that these tubercles multiply
under the influence of cold and wet, at least I have
found that horses so exposed had a greater number of
tubercles in their lymphatic glands and other parts of
their economy." These (glandular) tubercles gTOw soft
and degenerate, become abscesses, and convert the

On Glanders and Farcy. 273

whole interior of the gland into little cysts, whose pa-
rietes are dense, cartilaginous and occasionally bony.
The cysts in inveterate cases are found in a state of ul-
ceration, similar to that which destroys the membrane
of the nose.

So far from being favorable, the Professor says,
" suppuration announces the advanced state of the dis-
sease, and tends, not to heal, but on the contrary to
destroy the morbid tissues. It is a bad practice there-
fore to promote suppuration. In fact, at this period,
the frontal and maxillary bones form a very perceptible
prominence, most commonly on the left side, which
latter circumstance adds to the ominousness of the
prognostic.

I have been pointing out all that relates to the dif-
ferent varieties of tubercles. Furthermore, the proper
tissue of the lungs is altered by. their presence; the
parts surrounding the tubercles change their condition ;
they become red, dense, hepatized, and more friable :
•the same as it does after fatal acute peripneumony. In
other horses, the contiguous tissue becomes firm, con-
densed, whitish, and resembles fibrous substance.
The indurated part is with difl^iculty divisible with the
bistoury, and seems to me to be the effect of chronic
inflammation. I have observed a third alteration, es-
pecially after the ulcerative decline of the tubercles ;
in which case the parenchyma is softened, blackish,
as if it were decomposed, exhaling an insupportably
fetid odor, which I cannot compare to any thing else
but cariosity.

" It is now time to return to the description of the
pulmonary tubercles. — I have observed three varieties
of tubercles in the lungs : the miliary, the pisiform,
and the unciform. These morbid formations are com-

274 Oh Glanders and Fara/.

posed of an envelope or cyst, and of a wliitish sub-
stance, easily crushed between the fingers, which
Messrs. Dulong and Labillardiere have found
to resemble osseous matter. Very considerable depo-
sitions of this bony substance are occasionally seen in the
proper pulmonary tissue ; especially in the ox species.
— When these tubercles are large, their number is li-
mited ; but the miliary kind are innumerable. While
forming, they are firm, organized, and always found in
the course of the blood-vessels, whose calibre is singu-
larly increased ; they grow and become developed like
any other organized bodies, without our being able to
offer any rationale of the process, or of the space of
time they continue organic, prior to their mollification
and degeneration : they commonly end in ulceration
and destruction of the pulmonary substance. The
lungs of such animjils present vomicae or cysts of va-
rious sizes, contain a thick reddish matter, at other
times a more liquid cheese-like matter."

M. DupuY has also found small, white, hard, mi-
liary tubercles within the parenchyma of the liver,
often in great numbers ; encysted pisiform tubercles iu
some cases within the parenchyma of the kidney ; and,
much oftener than either within the liver or kidney,
encysted tubercles within the testicles, constituting in
them a kind of sarcocele, which is not always eradi-
cated by castration. " The epididymis also participates
in this affection. — Sarcocele occasioned by external vio-
lence admits of being cured by castration ; but if it
originates in the tuberculous affection, the operation
proves inefficacious.

" As I said before, if farcy is regarded as a sequel of
scrofulous disease, the cellular membrane and the cutis
vera, which are its seat, may be said to frequently un-

On Glanders and Farcy. 475

dergo similar changes ; indeed, peiliaps grease (eaux
aux jambes) results from the same cause. — I may add
that the same scrofulous action is also marked in the
bones, periosteum, and cartilages, &,c. There is a
skeleton, in the Veterinary Museum at Alfort, the bones
of which are crooked, especially the radii and tibiae:
these bones, together with the under jaw, are covered
with many, irregular, spongy exostoses. There is in the
same cabinet, a scapula perforated from the effects of a
farcy tumor ; also enlarged puffy cannon bones, sequels
of the same disease. — Specimens of nasal septa sof-
tened and destroyed by miliary tubercles." — In fine,
"it is manifest that this scrofulous or tuberculous evil
spares no part of the system. — Animals who are the
subjects of it mostly die about the sixth or seventh
year of their age : an additional consideration that
ought to engage us in researches in. what relates to this
fatal malady, in order that we may be able to decide,
by positive experience, whether or not it be hereditary ;
for, then, we shall have hit upon le veritable preservatif.

'* In reporting particular authenticated cases, it ap-
pears to me to be of great importance to prove, that
glanders, at the' time it first invades internal parts, is
latent ; from which it may be inferred that the elements
composing what I have named scrofulous tubercles,
coalesce under the influence of causes which appear to
me to be hereditaiy, as also under that of cold and hu-
midity. Though the cause were unknown to us, how-
ever, the effects I am describing might equally the
same exist. The tubercle forms without our being able,
by any certain signs, to direct attention to the time of
its development. In fact, the animal, the subject of
these active morbid phenomena, enjoys good health up

476 On Glanders and Farcy.

to the disorganization of" the tubercle, and those inter-
nal changes of it which end in its mollification and ul-
ceration.

" How to determine what constitutions are most lia-
ble to become glandered ? How to obtain a knowledge
of the circumstances concerned in working this tuber-
culous conversion in organized parts ? under what in-
fluences it takes its origin, proceeds, and terminates ?
how far it is hereditary ? how cold and humidity can
operate in disposing the animal economy to breed
this malady ? to what extent the impressions of cold
and humidity require to be made to excite the deve-
lopment of tubercles, the absorption of the earth of
bones, or the production of hydatids? These are
questions I cannot answer." — Though observations
would lead us to reduce these changes to two principal
causes : " namely, the injiueyices of external agents and
the crossijig of breeds." Change of climate is certainly
one general cause of constitutional derangements, es-
pecially when the emigration takes from the North to
the South.

Horses disposed to glanders are characterized " by
their ill-conditioned, lank appearance ; by their being
soft and early fatigued ; by the irregular and difficult
protrusion of their teeth * ; by the coarseness of their
heads, and their heavy inexpressive looks. The specific
opthalmia (la fuiion lunatique) affects the horses of
certain northern countries ; their growth is not kind ;
these horses are called washy ; (chevau^ decousus;) the
carcass is let down, the limbs become long and lank.

* " La protrusion des dents est irreguliere, difficile.*' pag. 58.
op, cii.

On Glanders and Farcy. All

I shall conclude this part of our subject by observing,
that the different names which have been given to inci-
pient glanders have contributed to banish truth from our
inquiries. Affections, which are but consecutive, have
been described as essential. Authors in general have re-
garded strangles as a distinct disease, but Gilbert,
who has taken a more enlightened view of the subject,
considers it as an effect of the same specific cause as
glanders. The symptoms, he observes, of strangles do
not differ from those of glanders. And, if the differences
between them be not essential, sufficiently so to consti-
tute two distinct maladies, he cannot but view glan-
ders as an imperfect strangles. Bastard-strangles ap-
pears to him to verify this proposition. The malady
comes on with all or nearly all the characters of genuine
strangles, and yet it is milder in this form. How often,
asks this author, does not one witness the disappear-
ance almost all at once of the fever and inflammatory
symptoms ? The enlarged glands, whose heat and
elasticity seemed to announce a speedy suppuration,
become, suddenly almost, cold and indolent ; some-
times they vanish very rapidly ; the flux continues and
resists all repellent means ; in a word, the horse be-
comes the subject of the most decided glanders. This,
the ordinary sequel of bastard-strangles, is sometimes
the termination of true strangles. If, with these facts,
notorious to every practitioner, we consider that glan-
ders is acute, inflammatory, and has really all the cha-
racters of strangles ; that in asses and mules, glanders
almost always takes this course, it seems to Gilbert
that it is not possible to overlook the perfect identity
existing between two diseases which to this day have
been viewed as essentially different.

478

On Glanders and Farcy.

'* I coincide in opinion with Gilbert in one point ;
and that is, I beheve strangles, bastard-strangles,
farcy, grease, and specific opthalmia, to be very fre-
quently the effects of the same specific cause ; and
these effects to be ascribable to the tuberculous aflfec-
tion. This is not a speculative or gratuitous opinion ;
I have reported observations placing it beyond doubt
or dispute.

The tuberculous affection varies in its symptoms
according to the part or tissue in which it is seated. I
have observed — \st. That it attacks the mucous mem-
brane lining the frontal sinuses, the maxillary, sphe-
noidal, &c.

" Idly. That the mucous membrane of the chambers
of the nose is frequently its seat.

'idly. That the lungs are often affected.
A^tldy. That the sublingual lymphatic glands are
constantly altered, disorganized by this disease.

"bthly. That other systems in the economy are
equally subject to it : I may mention the skin, the
subcutaneous cellular tissue, the testicles and the
epididymes.

One would expect that a disease which attacks
parts so unlike in their organization would assume very
different forms : this is observed in the present in-
stance.

I have no need to show that the disease will be
more serious and more quickly mortal in proportion to
the number of tissues affected in the same animal :
proofs of this are not wanting, if such averments re-
quired demonstration.

" The progress of glanders in the mucous membrane
lining the sinuses is very tardy ; which I attribute to the

On Glanders and Farcy. 479

diminished vascularity and consequent inferior organi-
zation of that part, to the membrane extended over the
chambers of the nose.

" Glanders is observed to be more active when seated
in the portion of the nasal membrane investing the tur-
binated bones or the septum.

" The tuberculous affection advances very slowly
when its seat is the parenchyma of the lungs. — In this
instance, it assumes the appearance of catarrh, perip-
neumony, pleurisy even, mourning of the chine, gan-
grenous peripneumony, &,c. all consecutive effects, in
certain cases, of the present affection.

It is difficult to point out clearly the signs which
denote this disease in the sinuses ; they are so obscure,
that the observation and dissection of a great number
of subjects are required to make this variety recognis-
able. While the animal is living, a slight prominence
of the affected sinus may be remarked ; the eye is di-
minished and humoury ; (chassieux ;) the lids are tume-
fied ; the inferior one has a prominent doubling, (hour-
relet) in it ; the conjunctiva is pale and infiltrated, and
so are the membrana nictitans and caruncula lachryma-
lis ; the tears flow over the face ; the skin covering the
aiTected sinus is thickened, puffed, and likewise the
cellular membrane and periosteum. In tapping witli
the finger upon the region of the diseased sinus, the
animal flinches from the impressions, thereby evincing
pain there ; should he submit to this test, he shuts his
eye, with a blinking movement of the lids, when the
blow is received upon the diseased cavity ; the sound
occasioned by the experiment is morbidly dull and ob-
scure, which is an indication that the membrane is
thickened, or that the sinus is full of puriform matter.
After death, we find that the membrane has undergone

480 On Glanders and tare it/.

rather the cancerous than the scrophiilous degener-
ation.

" When the mucous membrane of the chambers of
the nose is affected, the sublingual (submaxillary)
glands become tumefied, and undergo some very va-
riable changes : in fact, they grow, in the same animal,
swollen, firm, painful and moveable. Shortly after-
wards, they become insensible, diminished in volume,
and appear to resume their natural condition ; then
again, all on a sudden, they begin to swell once more,
and in the course of a few days grow larger than ever.

" In order to become well acquainted with all the
characters which may serve to distinguish incipient
glanders from catarrh and peripneumony, whose forms
it assumes, it will, I believe, be necessary to revert to
the constitution of horses most subject to glanders, and
afterwards point out the most remarkable changes the
disease effects in the constitution or organization of sub-
jects laboring under it.

" If, after an attentive exammation, we find that the
diseased horse has been reared in a low, wet, marshy
country ; if he shows the characters of such an origin,
viz. flat feet, long-hairy legs, exuberant chesnuts *, &c ;
or if he has a narrow chest, razor back ; if he is high
upon his legs, loose-made, &c. ; if he coughs easily ;

* " Chataignesy So the modern French writers designate the
oviform, horny, hairless eminences, found in the horse species
upon the inside of the arms and the hind legs, just below the
hocks. For niy own part, I am quite at a loss for an English ap-
pellation for them, and so I have followed the French comparison,
and named them chesnuts. Garsault, speaking of them, savs,
" Quelques-uns appellent cette come er^o^; mais il vaut mieux,
comme plusieurs auteurs, I'appeler chaiaigne ou lichen, pour la
distinguer des ergots, autres parties que nous verrons ci-apr^."
Le Nourveau Forfait Marechal. pag. 5.

On ( I landers and Farcl/. 481

if he becomes soon fatigued, 3cc. ; if he has been some
time exposed to cold and humidity, and fed through
necessity on over-dried, musty, rushy provender, and on
that in sparing quantities ; if one perceives marks of
suppressed oedema, &c. ; if, combined with all these
signs, the mucous membrane of the nose is thickened,
infiltrated, discolored, as likewise the conjunctiva
and membrana nictitans ; if one of the eyes appears
sunk, gummy, &.C. ; if the external nostril is curled in
and fouled with the mucus sticking about it, notwith-
standing neither tubercles nor ulcerations (vulgarly
called chancres) are apparent ; almost to a certainty an
animal uniting these symptoms is afl'ected with glan-
ders in the first stage. If the subject thus character-
ized is a gelding, and of the northern race ; and has
inhabited a stable, cold, humid, low, by the side of
some ditch or river, &c. any remaining doubts become
dispersed. If the nasal flux is found to be the sequel
of catarrh, strangles, or cynanche, and the animal,
after recovering his spirits on the cessation of the in-
flammation, eats and drinks and works as if he were
in health, notwithstanding the discharge continues un-
diminished ; if the skin is di-y and adherent, we may
boldly and without apprehension of being deceived, re-
gard the horse as glandered, especially if any ulcer-
ation is perceivable towards the ethmoidal sinuses.

" We must not take the disappearance of the out-
ward symptoms of these maladies for radical cures ; a
case of frequent occurrence, but one in which the tu-
berculous disposition still remains, in fact, I have
seen several times glandered horses considered as cured,
and symptoms characteristic of the disease have ap-
peared again after an interval of a month or two. One

PART III. 2 1

482 On Glanders and Farcy.

case is here reported wliich shows that all apparent
symptoms may be suspended for nearly a twelvemonth.
This happens when the tuberculous affection attacks
some internal viscera, such as the lungs. This suspen-
sion or intermission also takes place when the tubercles
undergo conversion : so that we find the internal dis-
ease increasing, while the external affection is vanishing
away. We must not therefore look upon these changes
as certain indications of cure.

*' I have related cases of horses destroyed in a few
days by acute diseases, which on dissection have pre-
sented tubercles in the nasal membrane or pulmonary
parenchyma. These lesions evidenced the existence of
the tuberculous affection ; which proves that, with
every appearance of excellent health, these horses
were attacked with a disease which would have de-
stroyed them at some subsequent period, if the acute
affection had not carried them off prematurely.

" From the foregoing observations and facts appear
deducible :

" \st. That it is difficult to detect glanders in its
primitive form.

" 2ndly. That it remains long latent within the sub-
stance of the affected tissues without disturbing their
functions.

" Mly. That in the course of this long period, one
of two or three years and sometimes longer, it is con-
founded with many other diseases supposed to be idio-
pathic ; whereas they are but symptomatic.

" Athly. That the distinctions between them are not
simply affairs of curiosity, but even serve to elucidate
the diagnosis.

" bthly. That it is at all times easy to recognise the

On (jr hinders and b\in y. 483

disease on dissection, since tubercles are found in several
of the tissues.

" Qthlif. That incipient glanders in living animals
is not so easily detected.

" Ithlif. That the perusal of the works of those au-
thors who have written on the subject, convinces us
that they have overlooked the first stages of glanders.

8M/j/. That strangles, or rather bastard-strangles,
is often an effect of this disease.

" Stilly. That glanders takes on many different forms
before it assumes that by which it is characterized.

" \Othly. That the incipient or Jirst stage of glanders
of authors, is already of long standing.

" Wthly. That at this period, apparently its onset,
it is almost always incurable.

" \1thly. That it is of great importance to treat it
while the tuberculous diathesis remains.

" \2thly. That, once developed, tubercles are no lon-
ger susceptible of a favorable resolution.

" \Athly. That if glanders can remain latent in
horses who enjoy vigorous health, experiments made to
determine its contagiousness, may prove fallacious and
lead to erroneous conclusions.

" I5thli/. That latent glanders may, at the very mo-
ment the experiment is made, when the poison has
been apphed to the nasal membrane, break out in the
most unambiguous form : thus it will make its appear-
ance during the experiment ; but it existed heretofore.
. " XQthly. That I have received proof that such expe-
riments are not so practicable as some would have us
believe.

"\lthly. That the contagiousness of glanders yet
remains an unsolved problem.

2 1 2

484 On Glanders and Farcy.

ISthly. That almost all veterinarians have adopted
the idea of contagion ; though some have advanced
quite the opposite opinion.

" Idthli/. That veterinarians regard this as a part of
the established doctrine ; though there are many proofs
to the contrary.

" 20thly. That I know of no well-conducted experi-
ment in favor of contagion, whereas there are some
against it.

" 2\st. That if I raise doubts about the contagiousness
of glanders, it is with a view of inducing Government to
order some experiments to be directed to this object.

" It is manifest, then, that all has not yet been said
on the subject of glanders ; and that my work is not
come too late. — I shall even leave many points yet to
be cleared up.

" Furthermore, observation has shown that the puri-
form matter coming from the bronchiae, which is dis-
charged by the nose, does not cause glanders in passing
over the nasal membrane, as veterinarians have ima-
gined. Glanders, in my opinion, is a specific disease ;
and not a termination of strangles, bastard-strangles,
cynanche maligna, farcy, watery farcy, catarrh, 8cc.
When the lungs are affected, it is a sequel of the tu-
berculous disposition, and not a termination of perip-
neumony. On the contrary, acute or chronic perip-
neumonies are very often consequences of the tubercu-
lous affection."

Latent Glanders. — Morve Cachee.
Under this head M. Dupuy presents us with twelve
cases in detail, which go chiefly to show— -The latent
nature of the disease, which is such that it is not dis-

On Glanders and Farcy. 485

coverable during life by the most experienced practi-
tioner— That tubercles not only exist in the first, but
even in the second degree of development in the inter-
nal viscera, without deranging their functions, parti-
cularly in the lungs — And that the affection disappears
for a time, and after\vards breaks out again without
any determinate causes.

" Conclusions from the First Part.

"The symptoms announcing the development of the
tuberculous affection, are very shght and difficult of
detection. Taken singly, it would be impossible to
make any satisfactory induction ; but in the aggregate,
they may furnish an able practitioner with some useful
eclaircissements. — If, then, the nasal membrane is pale,
thickened, and infiltrated ; if the submaxillary glands
are tumefied and collected in bundles ; if the coat is
discolored and arid, the skin tight, and there is no
perspiration ; if the gums are infiltrated and pallid ; if,
with these slight characteristics, we find that the
animal has sojourned in a marshy, shady country ; if
he has been at bivouac, exposed to cold and humidity ; if
his provender has been of bad quality, rushy, musty,
&c. ; if he has had frequent catarrhs ; if he has had
relapses of strangles ; if he has had bastard-stran-
gles, chronic or malignant nasal discharges ; if he
perspires from little work ; if he coughs habitually ; if
he shows signs of grease or farcy ; if his constitution
marks him to be of northern origin, to have been
reared in a shady pasturage, where he has undergone
a sort of over-growth ; ( kiolement ;) if the chest is nar-
row, the withers razored, the belly sunken, the feet
flat, the chesnuts prominent, the coat and long hairs
strong and abundant ; if he has been castrated ; if he

486 On G/anders and Farcy.

has a slight flux from the left nostril alone ; it is very
probable that in such a horse tubercles are developed,
notwithstanding even that the eye cannot discern any
in the nose. It becomes our duty therefore to place
him in such a state, and submit him to such a regimen,
as will be hereafter described, when I come to treat
of the curative, and, above all, of the preservative
means.

"SECOND DIVISION.

" The Tubercles grow soft, and, in becoming disorganized,

ulcerate.

" It requires likewise some share of penetration to
discover the commencement of the period now under
consideration : the tubercles being in small numbers,
and still preserving their organization, they occasion
but very little disturbance to the functions of the or-
gans in which they are seated. It is towards the end
of this second period, when the tubercles become dis-
organized, that the phenomena are rendered manifest,
and the functions seriously disordered ; the animal still
keeps his embonpoint, during the whole of this period,
though the mollification the tubercles undergo interiorly
disposes him to inflammatory disease : his embonpoint
is doubtlessly the reason why these inflammations or
phlegmasiae are attributed to quite another cause and
treated as such ; little are they thought to be the ef-
fects of the tuberculous affection ; it vi'iW therefore
prove very useful to determine well the nature of these
diseases ; since at this period we might yet succeed in
suspending the progress of the tuberculous affection,
though it were not possible to eradicate it. When we
come to examine horses who have died of such acute
diseases, we find tubercles softened into suppuration,

On Glanders and Farcy. 487

if I may view their disorganization or destruction as a
veritable suppuration : an expression 1 introduce here in
accordance with general usage. — The tuberculous affec-
tion is not then a termination of acute or chronic phleg-
masia}, of nasal fluxes or bastard-strangles, as veteri-
narians believe, who say, when the inflammatory symp-
toms are dissipated, that the case is doubtful, suspicious
of glanders. — By reading over the cases I have collected,
we may satisfy ourselves that the tuberculous affection
displays different lesions which may lay the founda-
tion for several varieties. I believe that, in the mean
time, I might insist that it often degenerates into a
schirrous or cancerous affection. This transformation
is frequently manifested in the disease we call farcy. —
In summing up the cases I have reported, it will be re-
marked, that of those horses who had only the nasal
membrane aft'ected, there is but one case in which the
right nostril was the seat of disease ; whilst there are
eight cases having the disease on the left side. It is
without doubt a particularity that the membrane of the
left chamber of the nose should be most frequently the
seat of the tuberculous affection ; it is not very favor-
able to the idea of glandered contagion ; it even con-
tradicts what is advanced on that subject. In the
greatest number, the membrane of both nostrils was
diseased ; in almost all, the lungs were filled with tu-
bercles, either in a hard or suppurated condition. I
have annexed thirteen cases, the subjects of which
had, at the same time, the tuberculous and schirrous
affections combined in the nasal membrane ; and
eighteen, in which glanders was complicated with
farcy.

" In my opinion, then, glanders ought to be viewed
as a specific aflfection ; and not considered as an un-

488 On Glanders and Farcy.

toward termination of strangles, bastard-strangles,
grease, and farcy. I would rather admit that all these
diseases are different forms assumed by the tubercu-
lous affection. — And then, bastard-strangles, malignant
strangles, specific opthalmia, and grease, would be
nothing more, in my mind, than effects of the tubercu-
lous affection.

'* I have insinuated that the progress of this affec-
tion is very tardy ; that the tubercles seem not to dege-
nerate until the organic tissues have undergone almost
an entire renovation. It would be curious to observe
if these animals sink four, six, or seven years after the
development of tubercles *. I have remarked, that
what gives rise to the tuberculous affection, has a sin-
gular influence upon nutrition, and consequently upon
the vital action, these phenomena being mutually de-
pendent. But all these operations elude our observa-
tion ; we must be content to examine the results, and
investigate how deranged particular functions affect the
economy of general life, and influence the generative
operations.

" Perhaps these considerations will show the difficulty
of curing such maladies, and engage us in the employ-
ment of preservative means, which are greatly more
interesting and serviceable ; since we might, by a ju-
dicious selection of mares and stallions, breed a race of
horses insusceptible of them.

" THIRD DIVISION.

" Considerations on the Acute Glanders.
Glanders called acute is a disease of another order.

♦ " I think I have received evidence that animals so affected from
hereditary causes rarely survive the seventh year."

On Glanders and Farcy. 489

We must not confound it with the tuberculous aifec-
tion : it has rather some analogies with the typhus of
horned cattle, or with the general epizootics, which, at
different times, have ravaged France and Europe. We
may also discover some affinity between glanders named
acute and the angina and peripneumony called gangre-
nous. All I am desirous of impressing, is, that this
disease cannot be considered as glanders ; the nature,
symptoms, lesions, and means employed in one and in
the other, all conspire to distinguish them. Another
reason for adopting a distinction would be, were it
proved, that a horse once cured is not liable to be af-
fected a second time. And if observation should show
that the acute glanders is highly contagious ; this and
the latter circumstance would approximate it to the rot
and typhus in homed cattle."

From several fatal cases, reported with great accuracy,
M. DuPUY sums up his more important observations
after death, as follows.

" Muscular System. Muscles blanched, fibres soften-
ed, pale-colored along the back, and upon the shoulders
and withers ; their interjacent cellular membrane in-
filtrated with a yellow serocity or distended with an
aeriform fluid. Those of the withers appeared as if
they had been scorched.

" Mucous System. The mucous membrane of the tra-
chea, as well as that of the bronchiae, violet-hued ; the
internal membrane of the aorta, red, infiltrated, thick-
ened, and easily lacerable, as was also its fibrous tunic.
The internal membranes of the crural arteries and caro-
tids, the venae cavoe and diaphragmatics, were equally
reddened. These vessels were full of blood, black, and
perfectly liquid, frothy and spumous, as if it had been

490 On (Jr landers and Farcy.

beaten up with so much air ; the blood contained in the
heart has had the same observation made upon it. Tlie
tissue of the heart was quite flabby, softened, pale,
blanched ; nevertheless, blood was found extravasated
among its fibres, especially upon the internal surface,
there being numerous ecchymoses within both the ven-
tricles.

" The parenchyma of the lungs appeared violet-hued
and softened ; air was found within the cellular tissue
connecting the lobules. This remark is important.
How was this gas produced ? The same pulmonary em-
physema is observed in the typhus of horned cattle.
Has the disease in question any analogy to typhus ?
This question merits our serious attention, and espe-
cially when we remember that a reddish sanies abounds
in the cellular tissue of the aflfected regions. This yel-
lowish sanies had become concrete and firm upon the
withers, where the spines had grown carious from the
alteration within the cavity of the abdomen. The me-
senteries were red at their origin.

" The brain was pale and softer than ordinary ; the
plexus choroides of the cerebrum and cerebellum, yel-
lowish and infiltrated ; the pituary gland alike disco-
lored, which formed a contrast with the violet hue of
other parts : the sinuses of the bones of the head have
also been discovered full of this red serocity.

''The sanious matter obtained from these sweUings,
introduced under the skin of the neck of a horse in
health, produced a similar affection, of which the ani-
mal died on the fifth day. The symptoms and lesions
observed, manifested no differences of importance. I
have repeated these experiments on several other horses,
and also on sheep. I have uniformly obtained the same

On Glanders and Farcy. 491

results ; whilst a dog who licked and swallowed the
matter, escaped infection." The

FOURTH DIVISION,"

Treating of the " Tuberculous Affection of Domestic
Animalsy compared trith that of the Horse" I shall pass
over, and proceed to the

" FIFTH DIVISION.

" Treatment .

" If veterinary pathology has for its object the detec-
tion, description, classification, and treatment of dis-
eases according to the divers indications shown by them,
it will be agreed that a crowd of circumstances con-
spire to embarrass even the best informed practitioner,
which claim from him no ordinary sagacity to enable
him to institute a judicious method of cure. — The ef-
fects of this destructive disease are sometimes mani-
fested by tubercles upon the exterior of the body : these
morbid productions are readily dispersed, especially
when their development commences. But such cures
are rarely complete ; the tubercles very often become
reproduced. This relapse of a malady believed to have
been cured, manifests extreme obstinacy ; it resists
means holding out to all appearances the most flatter-
ing prospects. It is also observable, that the remedies
which prove successful in one case, will often have the
very contrary effects in another : this is owing to the
variation in the virulence of the disease, and to the
greater number of tissues affected, as the lymphatic
glands, the mucous membrane of the nose, the pulmo-
nary tissue. The veterinarian therefore should endea-
vour to frame a system of therapeutics capable of em-

492 On Glanders and Fairy.

bracing every indication, and cast away the specific re-
medies offered to us with such boasted assurance, which,
so far from being beneficial, are very often injurious."

After having laid before us (avec trop de complaisance
peut-etre) the different means proposed, by the an-
cients as well as the moderns, for combatting the tu-
berculous affection, M. DupuY continues — "The ex-
perience of past ages cannot be set off against me.
What advantages do we gain from such experience ?
What does the mind glean from the perusal of these
different veterinary works ? I repeat, two leading hy-
potheses are discoverable (in these works). The one
attributes glanders to an acrimony circulating in the
blood : to which account they lay all disorders that
may supervene upon it. The partisans of this proof-
less supposition imagine that they will achieve a cure
if they can but manage to eliminate or expel this pre-
tended morbific humor ; to the fulfilment of which
grand desideratum, eveiy remedy employed is directed.
According to the second supposition, glanders is viewed
as a local affection, attacking the mucous membrane
of the nose. Those who have adopted this opinion em-
ploy fumigations, and trepan the frontal and maxillary
sinuses. Moreover, they have invented instruments to
conduct these vapors and fumigations into the different
windings of the nasal cavities, with the intention of
locally affecting and bathing the diseased parts, and in
the end of cicatrizing the chancres by vapours charged
with medicinal exhalations ; but unfortunately, all
these means, whose combination appears so happy,
have not been followed by the anticipated success. It
certainly is surprising to one who has attentively pe-
rused the different works on glanders, from the time of

On Glanders and Varcy. 493

Aristotle to the present, that he has met with nothing but
a multiformity of suppositions, and not one author who has
busied himself' about the nature of this mortal maladi/.
They have all disresjarded this important part of patho-

logy."

In laying down the treatment, " I shall commence
with an exposition of the preservative methods. And
these I shall consider in two different points of view.
First, I shall inquire if the disease be hereditary, and
afterwards examine the simplest and most practicable
means within our reach to preserve the species. Se-
condly, I shall endeavour to decide whether glanders
in horses, or tubercular phthisis, can be the product of
a contagious miasm.

"It is more prudent and advantageous to prevent
a disease than to be compelled to combat one." — The
influence of climate is very remarkable on animals,
not only in altering their special characters, but as it
affects their morbid dispositions. The first is evinced
in sheep more particularly, whose breed alters with the
country into which they may be transported ; and the
second is evidenced in negroes and monkeys who are
brought over to England, where many of them con-
tract scrophula, a disease there endemic. Such also
is the humidity of the climate that the rot is very pre-
valent there among the sheep, which, on that account,
are sent at an early age to the butchery. " This corrobo-
rates my view of the subject, and evinces the great in-
fluence that cold combined with humidity exercises
over the animal economy.

" That person will render an important service to his
country, and to rural economy in general, who may

494 Oh Glanders and Farci/.

show by incontestible evidence that these organic dis-
eases are very often hereditary : the veritable preserva-
tive would be discovered were this point once established.
— I knew a mare whose body on dissection presented
every appearance characteristic of glanders : her filly
died at the age of 4^ years of the same tuberculous af-
fection. The other offspring of this mare inherited her
particular conformation, and her propensities to bite
and kick. Another mare and her foal discovered on
being opened the same organic lesions as the preceding
animals. I have made the same observation on the ex-
amination of a third mare and her foal. These facts
were attested by the Professors and Pupils of the Veteri-
nary School at Alfort ; so that they combine unques-
tionable authenticity. The lesions I have been men-
tioning were too evident and well-marked to admit of
the possibility of any serious mistake." — Here follow
other similar observations in relation to oien. sheep,
and swine, showing that the tuberculous disease in
them, which takes other names — la pofnmelitre des
vaches, the rot, and the husk, is likewise transmitted
from one generation to another. Indeed, says Dupuy,
" I have gathered some facts together proving that the
specific opthalmia affecting the horses of certain parts
of France, is very often likewise the product of an
analogous cause.— M. Corvisart tells us, that from
the defective conformation which we derive from our pa-
rents, springs the germ of every species of organic dis-
ease. I am thoroughly convinced, says this author,
that hereditary influence is more powerful and exten-
sive than physicians of the present day have yet con-
ceptions of. I firmly believe that a very great propor-

^3/

On Glanders and Farcy. 495

tion of diseases, especially of those that resist the ef-
forts of art, arise from causes which, whether they be
organic or humoral, are hereditary, and consequently
insurmountable. Take for example phthisis pulnionalis.

" These considerations to us are of the greatest mo-
ment, since we have it in our power, by coupling
and crossing well-known breeds, to lessen the num-
ber of animals predisposed to these diseases. Act-
ing up to such ideas, our line of conduct is marked
out. We must banish from establishments designed to
improve the breed, such animals as show any signs of
tuberculous disease or any analogous affection. Above
all, no stallion should be allowed to remain in a wet or
cold situation, in consequence of the evils likely to re-
sult therefrom. — I quit with regret so interesting a sub-
ject, one which I propose one day or another to return
to again. These preservative measures, if they were
generally adopted, might at least afford us consolation
for the unsuccessfulness of the different modes of treat-
ment hitherto employed.

" The question of hereditableness has not yet been
viewed in the light of positive physiology ; it is to be
presumed that the reader will readily receive the conclu-
sions I have laid down. But will this be the case with
the question I am now going to agitate ?"

The Professor follows this remark with several de-
tailed observations and experiments, received or ex-
tracted from some of the most respectable veterinary
authorities in France, which go to disprove the opinions,
in favor of which the public are so prejudiced, of glan-
ders being a contagious disease. In the course of these
relations, it is said, that in regiments of cavalry, to
preserve consistency, when the appointments of a horse,

49ti On Glanders and b'arcy.

sacrificed for having glanders, are destroyed, the clothes
of the man who looked after him should also share the
same fate, and even the stable itself, adds Dupuy, be
burnt, since boiling water is said not to annihilate
the poison, and the lime which is spread over the sur-
face of the stall, soon falls or breaks off' again : this
would have been reasonable enough at the time that
ViTET counselled all the sovereigns in Europe to have
slaughtered on the same day every glandered and sus-
picious subject in their respective dominions, in order
to exterminate the disease altogether. In closing this
part of his subject, M. Dupuy observes — "What I
have just related is the bare truth, resulting from ob-
servation and experience, the two principal tests we
possess for proving these points with accuracy and pre-
cision. I trust I have submitted my evidence with all
possible circumspection ; I declare that I have consi-
dered the subject medically, and not in accordance with
the views of the administrative police. It has been my
wish to combat with prejudices. It will be seen that
my object has been utility. Have I fulfilled this object
without intentional offence to any person whatever ?
The reader is to decide ; and I trust that the essay will
meet with his indulgence.

General Observations relative to Glanders.
" From my own experience and that of some of my
colleagues, it would appear that glanders is rare in very
cold countries, and absolutely unknown in hot climates.
From and throughout Poland to about the middle of
France, glanders is frequently seen ; it is not commom
on the other side of the Pyrenees; it is unknown in
Africa. M. Vuillaume, my colleague and friend.

On Glanders and Farcii. 497

ascertained this Tact during- his stay ut Tunis and Tau-
giers. M. Simon, veterinary surgeon to the King of
Portugal, assured him that he had not seen a glandered
horse during the thirty years he had been residing in
Lisbon .

" Is a cold and humid temperature the only cause ?
Might not we suspect that castration contributed much
towards it ? I have observed, that this disease more
f requently attacks geldings than stonehorses and mares.
We know that in countries wherein glanders appears to
be enzootic, it is the custom to submit horses to this
enervating operation, one which stamps his form and
character with the seal of imbecihty and pusillanimous-
ness. We know that the immeiise tribes of wandering
Tartars, the Cossacks upon the borders of the White
Sea, the Kirguses, the Bashkirs, and the Nogayans,
the Basians, the Karakalpaks, and the Kalmucks,
who make as much and perhaps more use of horses
than we do, are unacquainted with any means of depriv-
ing them of their organs of reproduction. We arc as-
sured that they have no knowledge of the disease
under consideration, which, if it be true, will con-
firm what I have just been advancing. In Spain, Bar-
bary, Egypt, and Arabia, all the horses are entire.

We observe that glanders less frequently atfocts
horses of small stature, those of slender . make, but
muscular and high-couraged, than large, coarse, phleg-
matic subjects. It would appear that a certain period
of age is favorable to its development. I have no-
thing very positive to offer on this point ; so far as my
observations go, they show that among forty glandered
horses there were but two under five years old, and but
five above twelve.

PART J I J. 2 k

^'^8 Oil (i landers and Fa ret/.

" Since the publication of the interesting work of M.
Go DINK, Jun. we have remarked that out of eleven
cases of glanders there were but two affected in the
l ight nostril : seven discharged from the left, and two
from both sides.

" Most of the authors who have written on glanders
hiave servilely copied one another. They have thrown
together symptoms to characterize it which belong to a
host of other disorders. I can reckon upwards of sixty
causes of glanders enumerated by them. Among so
many, they were certain almost of naming the real
one." — Among the causes enumerated, are — 'damaged
provender ; over-fatigue ; the influence of cold and hu-
midity ; low, wet, dark habitations, infested with ctlr-
rents of' air charged with effluvia from the animal matters
nccumulaled about the door and windows of stables, the
atmosphere of which is not sufflcientiij often renewed, and
which are situated by the side of rivers, rampart walls,
garrison towns, &c. ot*.s4<;i

Conclusion^/ ->^^i^i^i i*.i3fl955

"We learn from experience that certain horses liTe a
long time affected with glanders, while others sink
shortly after the appearance of the primary symptoms.
It would be important, as regard therapeutics, to dis-
cover the cause of these remarkable differences in the
progress of the disease."

It has been shown in the first division, how difficult
or impossible it is to detect the origin of a disease
which in its incipient stage does not sensibly disturb
the functions of the organs wherein it is seated. " It
is at this period rather a morbific commotion, (un travail
morbifique,) a predisposing cause, than a real malady."

Oh GltiinJers atid Fain/. 49i.>

III the second period, the disease perhaps does not
appear to the owner serious enough to submit the ani-
mal to treatment, even sliould we be able to detect it, or
distinguish it from catarrh or pneumonia, and vkevermy
which we are not always certain of doing.

'* It is the duty of the veterinary surgeon to take
steps to remove the predisposing causes, or to resist the
pending attack, and treat the disease as soon as it
^i^akes its appearance. Now, the exciting causes of
tubercles or hydatids, I have stated to be, cold, humi-
dity, super-aqueous aliments, stables situate low^ ill-
-ventilated, wanting light, and placed over drains, nea,r
terrass- walls, ramparts, rivers, &.c. lastly, the exposure
of horses at. bivouac, in wet encampments, or their in-
habitation of iU-paved stables, whose atmosphere ,is
confined, and vitiated with the effluvia from the dung ;
and where food , is insufficient, and that often of bad
quality. It is of the first consequence to remove dis-
eased animals away from such deleterious influences be-
fore we set about combatting, with suitable measures,
the general diathesis to which the disease owes its
origin.

'* Let us bear in mind, in the treatjnent, that the
tuberculous affection consists in a molecular movement
going on in the affected organ, whence springs a morbific
production, endowed with an action opposed to that one
by which the organ is nourished in a state of health,
j^^ 13 theij this intestine movement that must be rectified
in order to make a radical cure. Is this rectification
well understood by us ? How is it to be carried into
effect ? What means are we to employ to restore the
nutritive action to its ordinary standard ? These indi-
cations are extremely difficult to accomplish.

500 On (jlandtra and Farcy.

" To be successful, it is evident that the beneficial
influences of regimen and Qiedicaments must be conti-
nued long enough to work a sort of metamorphosis in
the affected parts. In fact, what can one expect from
remedies which operate but in a subitaneous manner ?
They can only excite a superficial action, one that can
have no effect in altering the composition of the organ.
This excitement might even do harm ; a result always
to be expected when prescriptions are hazarded, with-
out having first learnt from experience the changes it is
expedient to bring about to arrest the progress of these
affections.

*' The treatment should be distinguished into what
relates to regimen or dietetic means, and into medical
treatment. The regimen should be corroborative ; the
aliments of good quality ; the infirmaiy in a diy airy
situation, avoiding low wet grounds, and be well ven-
tilated ; the work or exercise moderate, and during fine
weather ; dressing, hand-rubbing, and wisping are
useful, and supply the want of exercise when that can-
not Tje given. These means have a powerful influ-
ence on the constitution of subjects of the tubercii-
lous affection ; they retard its progress ; the disease
seems to be arrested, though it rans on enfeebled for
several years.

" Could we not introduce into the resimen of these
animals vegetable substances containing a large propor-
tion of azote, such as wheat and gluten ? And why
not add to this, vinous panadas and broths?" Vicq-
d'Azir assures us, that he has seen a great number of
beasts recover (from epizootics) after having taken meat
soups. In Sweden, according to the same author,
bread is made from oatmeal, by which it is found that

Oh Glanders and Farcy, 501

horses may be kept at one-half the ordinary expense. —
To these matters I propose some day to return.

" Among the great number of medicaments which
have been recommended for this affection, the best,
which are far from succeeding under a multiplicity of
circumstances, are tonics, such as gentian, elecampane,
tansy, aromatic powders, quinquina, hemlock, digita-
lis, and the phellandrium aquaticum. Among the mi-
neral substances, sal ammoniac, carbonate of ammonia,
ammonia, kermes mineral, emetic antimony, corrosive
sublimate, mercurius dulcis, the sulphurets of mercury
— cinnabar and ethiops mineral, sulphur, and sulphuret
of soda.

" Aloes, ammoniacum, assafcetida, resin, nitre ; re-
vulsive means, such as setons, blisters, firing the sides
to diminish the pulmonary inflammation often compli-
cated with this affection.

" Let not these medicaments, taken singly, be looked
upon as specifics ; (we have no such thing ;) but as
agents capable of producing beneficial effects in the
hands of scientific practitioners, when judiciously com-
bined and skilfully exhibited. I might have affixed the
doses and prescribed such formulae as I have found
most successful ; but, as I am persuaded that veterina-
rians stand in no need of this, I thought it superfluous
to insert them, thereby depriving empirics of arms they
might use injuriously to farmers, and acting up to the
laws in force which are in opposition to the institution
of any treatment likely to prove successful in combat-
ting the various complications of which the tuberculous
affection is susceptible."

Having at length arrived at the end of M. Dupuy's
profound, accurate, and scientific researches into the

502

On Glanders and Farcy.

origin and nature of glanders, by which we are led into
an entirely new channel of investigation, and therein
considerably enlightened in our progress, I shall (pur-
posely refraining from offering anything of my own on
the subject until such opinions as I may entertain shall
have been further matured) bring this series of lectures
to a conclusion. I may now with Dupuy say, " Ici se
termine la tache que nous nous sommes imposee. Elle
auroit exige peut-etre de notre part et plus d'exp6rience
et plus d'instruction." If I have evinced but accuracy
in my anatomical descriptions, correctness in my phy-
siological views, and faithfulness in reporting what is
known in veterinary medicine and surgery, I have ac-
complished my original design. I am not aware of
having made more than one very important omission ;
and that is the subject of the ear: though a part, as
far as my observations have gone, in the horse exempt
from disease, yet it is one entitled to a place in a regu-
lar course of anatomy. I hope, one day or another, to
take an opportunity of supplying the deficiency. The
foot has been past over by design. I considered that
what new or original matter I might have found to of-
fer on the subject, would hardly warrant me to break up
that ground afresh which has already been so extensively
cultivated through the labors of Messrs. Coleman,
Clarke, and Goodwin; and therefore I have re-
frained from making this important part an unprofitable
addition to the present series of lectures.

THE END.