This is a subject of great importance to the farmer; for many of the
diseases of cattle arise from the filthy, obstructed state of the
surface. This neglect of cleansing the hide of cattle arises, in some
cases, from the absurd notion (often expressed to the author) that the
hide of cattle is so thick and dense that they never sweat, except on
the muzzle! For the information of those who may have formed such an
absurd and dangerous notion, we give the views of Professor Bouley. "In
all animals, from the exterior tegumentary surface incessantly exhale
vaporous or gaseous matters, the products of chemical operations going
on in the interior of the organism, of which the uninterrupted
elimination is a necessary condition for the regular continuance of the
functions. Regarded in this point of view, the skin may be considered as
a dependency of the respiratory apparatus, of which it continues and
completes the function, by returning incessantly to the atmosphere the
combusted products, which are water and carbonic acid.
"Therefore the skin, properly speaking, is an expiratory apparatus,
which, under ordinary conditions of the organism, exhales, in an
insensible manner, products analogous to those expired from the
pulmonary surface; with this difference, that the quantity of carbonic
acid is very much less considerable in the former than in the latter of
these exhalations; according to Burbach, the proportion of carbonic
acid, as inhaled by the skin, being to that expired by the lungs as 350
to 23,450, or as 1 to 67.
"The experiments made on inferior animals, such as frogs, toads,
salamanders, or fish, have demonstrated the waste by general
transpiration to be, in twenty-four hours, little less than half the
entire weight of the body."
The same author remarks, "Direct experiment has shown, in the clearest
manner, the close relation of function existing between the perspiratory
and respiratory membranes."
"M. Fourcault, with a view of observing, through different species of
animals, the effect of the suppression of perspiration, conceived the
notion of having the skins of certain live animals covered with varnish.
After having been suitably prepared, some by being plucked, others by
being shorn, he smeared them with varnish of variable composition; the
substances employed being tar, paste, glue, pitch, and other plastic
matters. Sometimes these, one or more of them, were spread upon parts,
sometimes upon the whole of the body. The effects of the operation have
varied, showing themselves, soon or late afterwards, decisively or
otherwise, according as the varnishing has been complete or general, or
only partial, thick, thin, &c. In every instance, the health of the
animal has undergone strange alterations, and life has been grievously
compromised. Those that have been submitted to experiment under our eyes
have succumbed in one, two, three days, and even at the expiration of
some hours." (See _London Veterinarian_ for 1850, p. 353.)
In a subsequent number of the same work we find the subject resumed;
from which able production we select the following:--
"The suppression of perspiration has at all times been thought to have a
good deal to do with the production of disease. Without doubt this has
been exaggerated. But, allowing this exaggeration, is it not admitted by
all practitioners that causes which act through the medium of the skin
are susceptible, in sufficient degree, of being appreciated in the
circumstances ushering in the development of very many diseases,
especially those characterized by any active flux of the visceral
organs? For example, is it not an incontestable pathological fact, that
catarrhal, bronchial, pulmonic, and pleuritic affections, congestions of
the most alarming description in the vascular abdominal system of the
horse, inflammation of the peritoneum and womb following labor,
catarrhal inflammations of the bowels, even congestions of the feet,
&c., derive their origin, in a great number of instances, from cold
applied to the skin in a state of perspiration? What happens in the
organism after the application of such a cause? Is its effect
instantaneous? Let us see. Immediately on the repercussive action of
cold being felt by the skin, the vascular system of internal parts finds
itself filled with repelled blood. Though this effect, however, be
simply hydrostatic, the diseased phenomena consecutive on it are far
otherwise.
"It is quite certain that, in the immense system of communicating
vessels forming the circulating apparatus, whenever any large quantity
of blood flows to any one particular part of the body, the other vessels
of the system must be comparatively empty.[14] The knowledge of this
organic hydrostatic fact it is that has given origin to the use of
revulsives under their various forms, and we all well know how much
service we derive from their use.
"But in what does this diseased condition consist? Whereabouts is it
seated?
"The general and undefined mode it has of showing its presence in the
organism points this out. Immediately subsequent to the action of the
cause, the actual seat of the generative condition of the disease about
to appear is the blood; this fluid it is which, having become actually
modified in its chemical compositions under the influence of the cause
that has momentarily obstructed the cutaneous exhalations, carries about
every where with it the disordered condition, and ultimately giving
rise, through it, to some local disease, as a sort of eruptive effort,
analogous in its object, but often less salutary in its effect; owing to
the functional importance of the part attacked, to the external
eruptions produced by the presence in the blood of virus, which alters
both its dynamic and chemical properties.
"But what is the nature of this alteration? In this case, every clew to
the solution of this question fails us. We know well, when the
experiment is designedly prolonged, the blood grows black, as in
_asphyxia_, (loss of pulse,) through the combination with it of carbonic
acid, whose presence is opposed to the absorption of oxygen. But what
relation is there between this chemical alteration of blood here and the
modifications in composition it may undergo under the influence of
instantaneous suppression, but not persistent, of the cutaneous
exhalations and secretions? The experiments of Dr. Fourcault tend, on
the whole, to explain this. His experiments discover the primitive form
and almost the nature of the alteration the blood undergoes under the
influence of the cessation of the functions of the skin. They
demonstrate that under these conditions the regularity of the course of
this fluid is disturbed--that it has a tendency to accumulate and
stagnate within the internal organs: witness the abdominal pains so
frequently consequent on the application of plasters upon the skin, and
the congestions of the abdominal and pulmonary vascular systems met with
almost always on opening animals which have been suffocated through tar
or pitch plasters.
"They prove, in fact, the thorough aptitude of impression of the nervous
system to blood altered in its chemical properties, while they afford us
an explication of the phenomena of depression, and muscular prostration,
and weakness, which accompany the beginning of disease consecutive on
the operation of cold.
"How often do we put a stop to the ulterior development of disease by
restoring the function of the skin by mere [dry] friction, putting on
thick clothing, exposing to exciting fumigation, applying temporary
revulsives in the shape of mustard poultices, administering diffusible
stimuli made warm in drenches, trying every means to force the skin, and
so tend, by the reestablishment of its exhalent functions, to permit
the elimination of blood saturated with carbonic matters opposed to the
absorption by it of oxygen!
"Do we not here perceive, so to express ourselves, the evil enter and
depart through the skin?
"M. Roche-Lubin gives an account of some lambs which were exposed, after
being shorn, to a humid icy cold succeeding upon summer heat. These
animals all died; and their post mortem examination disclosed nothing
further than a blackened condition of blood throughout the whole
circulating system, with stagnation in some organs, such as the liver,
the spleen, or abdominal vascular system.
"From the foregoing disclosures, which might be multiplied if there was
need of it, we learn that the regularity or perversion of the functions
of the skin exercises an all-powerful influence over the conservation or
derangement of the health, and that very many diseases can be traced to
no other origin than the interruption, more or less, of these
functions."
These remarks are valuable, inasmuch as they go to prove the importance,
in the treatment of disease, of a restoration of the lost function. Our
system of applying friction, warmth, and moisture to the external
surface, in all cases of internal disease, here finds, in the authors
just quoted, able advocates.