themselves. Decency is in this respect a thing of comparison. An Indian
woman, with nothing but a narrow cloth around the pelvis, would be with
us an object at which the public modesty would be shocked. The habit
of mankind serves her as a veil in her own country. A female savage
transported entirely naked to the same country, would be indecent
there; she is not so in her own. Observe our fashions in their rapid
succession; a woman, who by not changing her costume, would have had
two years since, that of a courtezan, would now find herself dressed
with great modesty. Indecency in costume is that merely which shocks
our habit. The female Indian, with the rag that covers only a quarter
of her body, is more decent than the woman in whom a small opening
separated the neck-handkerchief in our old fashions. The sight of the
face shocks those people among whom females are veiled. Let us consider
then habit as the type of the decency of costumes. Nature has wished in
physiology, that the phenomena over which it presides, should be slowly
connected; it is the same in morals. The woman who suddenly changes her
dress from one that is close to one that is not, exposes herself to
painful sensations, to catarrhal diseases, &c. and shocks the eyes of
those who had been accustomed to see her in a different exterior. When
the change is gradually and insensibly brought about, neither health
nor morals are affected.
Habit does not modify the cutaneous sensibility which arises from an
alteration of texture, from an inflammation, &c. Powerfully raised in
this last state, it is much above its natural level. Then the least
contact becomes extremely painful; thus the skin is no longer then in
a state to exercise the sense of feeling. The touch itself does not
distinguish general sensations. All bodies make a common and uniform
impression, it is that of pain.
The animal sensibility of the skin sometimes diminishes and even
disappears; paralysis is a proof of this. These affections, more rare
than the loss of motion, often however take place. In the organs of
the senses, it is the eye which most frequently loses the sensation;
the ear comes next, then the skin, then the nostrils and finally
the tongue, which is the sensitive organ that is always most rarely
paralyzed, no doubt because it is that which is the most connected
with the support of organic life, without which we could not exist.
The others belong especially to animal life, which we can lose in part
without ceasing to exist.
The whole skin is never at the same time paralyzed; there is rarely
even hemiplegia in this respect; the feeling is not extinguished but in
an insulated part. I would remark that the existence of these paralyses
is also a proof of the want of nervous influence upon cutaneous
exhalation and the capillary circulation, since both go on very well in
this case as well as in paralysis of motion, as I have observed above.
Cut the nerves of a limb of an animal, in order to render this limb
insensible; if after this you apply an irritant, the skin will inflame
as usual.
When the animal sensibility is in exercise, is there a kind of erection
of the papillæ that they may feel more acutely? The same observation
may here be made as was in regard to the mucous surfaces. This erection
is an ingenious idea of some physicians, and not a fact which rests
upon observation. I even think that this contradicts it; for examined
with a glass the papillæ appear to be constantly in the same state. Why
should not the skin feel like a nerve laid bare, like the eye, the ear,
&c. in which these sorts of erections have never been imagined?
Animal contractility is wholly foreign to the cutaneous organ, which
moves voluntarily only by the influence of its fleshy pannicle.
_Properties of Organic Life._
Organic sensibility and insensible contractility exist in the highest
degree in the cutaneous organ. The external capillary system, which
forms the reticular body, is, as I have said, especially the seat of
these properties. They are in constant activity in order to preside,
1st, over the capillary circulation; 2d, over exhalation; 3d, over
absorption; 4th, over the nutrition of the whole dermoid texture;
5th, over the secretion of the cutaneous oil, if the sebaceous glands
exist. It is not astonishing that these properties should be so
much developed in the skin, in which they have so many functions to
support. Add to these considerations the constant action of external
bodies, an action which keeps this organ in continual excitement, which
incessantly stimulates its sensibility, which is to this sensibility
what that of the bodies contained in the mucous surfaces is to the
sensibility of these surfaces; the irritation is even more sensible,
because the stimuli are oftener changed. A thousand agents of nature,
of different density and composition continually succeed each other on
the exterior of the body, and at the same time that they act upon the
animal sensibility of the skin, to produce various sensations, they
excite the organic sensibility in order to support the functions over
which this sensibility presides.
Is it astonishing then that the greater number of cutaneous diseases
supposes an alteration in this property and in the insensible organic
contractility which is not separated from it? I divide these diseases
into four classes, according to the structure we have distinguished in
the skin.
1st. There are diseases of the papillæ; these are the paralyses and
various kinds of increase of feeling, which reside only in the nerves.
Women are especially subject to these last, which are so great in some
nervous affections, that mere contact of the skin if considerably
powerful produces convulsions. To this also should be referred the
extreme susceptibility of some individuals in whom tickling produces a
general revolution. It is necessary to distinguish these exaltations
of animal sensibility, from those of which we have spoken above, and
which depend upon inflammation. The organic sensibility is especially
affected in these last; we might say that by its increase it is
transformed into animal sensibility; whereas in the other case this
last property alone is altered.
2d. There are diseases which have evidently their seat in the cellular
texture which occupies the dermoid spaces; such are the inflammations
of the cutaneous portion which covers a phlegmon, a bile, &c.
3d. There are diseases of the external capillary net-work, from which
the exhalants arise. To this must be referred erysipelas, many species
of herpes, measles, scarlatina and many acute cutaneous eruptions that
are daily met with in practice.
4th. Finally, there are diseases in which the chorion is affected.
Elephantiasis, and in general many chronic cutaneous diseases appear
to me to be of this number, and I will even observe that the chorion
never appears to be primarily affected in acute diseases. The
obscurity of its vital forces, its dense and compact texture, and its
comparative want of vessels prevent it from accommodating itself except
to chronic affections. In phlegmonous erysi pelas, in biles, &c. it
is only influenced, but it is not essentially diseased. Thus we have
seen that all the affections of the osseous, cartilaginous, fibrous,
fibro-cartilaginous systems, &c. are really slow and chronic, on
account of the texture and the vital obscurity of these systems.
Now if we reflect on this division of cutaneous diseases, we shall see
that except those of the first class, which are not numerous and which
consist in greater or less alterations of animal sensibility, we shall
see, I say, that all the others suppose a more or less considerable
affection of the organic sensibility and of the corresponding
insensible contractility. All are derived from an increase, a
diminution or an alteration of these properties.
It is also to the different changes of these properties, that must be
referred the more or less copious sweats and the various exudations
of which the skin is the seat. In fact, the exhalant vessels remain
always the same in relation to their structure. Why then do they admit
a greater or less quantity of fluids? Why at certain times do they
allow of the passage of substances, which they repel at others? It is
because the modifications of their organic forces are changed. These
forces are often weakened in an evident manner in diseases; they become
languid and are prostrated. Then blisters are applied in vain; the
organic sensibility no longer answers to the excitement that is made
upon it. This is a striking phenomenon in ataxic fevers, and proves
the independence of the phenomena of cutaneous exhalation, capillary
circulation, &c. in regard to the cerebral nerves. In fact, whilst
during the paroxysm the brain is in extreme excitement, the voluntary
muscles are put by this excitement into a violent state of convulsion,
and the energy of the whole of the animal life seems to be doubled
before it ceases to exist, the organic is already in part exhausted;
the functions of the portion of the skin which belongs to this life
have already ceased.
The stimuli of cutaneous organic sensibility vary remarkably in their
degree of intensity. 1st. The strongest are fire, cantharides, the
alkalies, the acids sufficiently diluted by water not to act but upon
the vital forces and not to alter the dermoid texture by the horny
hardening, the juices of many acrid and corrosive plants, certain
fluids even produced in the economy, as those of cancers, &c. All these
stimuli redden the skin when they are applied to it. 2d. Most of the
same stimuli, diminished in intensity, stimulate it but slightly. 3d.
Finally, aqueous fluids, cataplasms and emollient fomentations seem
to produce this excitement the least; they even rather weaken the
cutaneous organic sensibility; they seem to act upon it like sedatives
and moderate the kind of excitement it produces in inflammations.
The same is true of most of the fatty substances; thus oils, butter,
grease, &c. are in general not calculated to keep up the suppuration
of blisters. It is requisite, in order to keep the skin at the degree
of organic sensibility, necessary for the purulent exudation that then
takes place, to mix cantharides with fatty substances.
The skin does not appear to enjoy sensible organic contractility.
Stimuli usually produce no other action upon it, than the contraction
imperceptible to the eye, which composes insensible contractility, and
which takes place especially in the small capillary vessels. There is
however one circumstance in which this contraction is, to a certain
extent, apparent; it is when cold acts briskly upon the skin, which it
wrinkles into goose flesh, as it is called. I have pointed out above
the mechanism of this contraction, of which the chorion is the seat,
and which holds a medium, like many motions which I have already had
occasion to notice, between the two species of organic contractility.
_Sympathies._
We shall still follow the division of the sympathies into active and
passive, a division which is more remarkable here than in most of the
other systems, because the sympathies are much more numerous.
_Passive Sympathies._
The animal sensibility is very often brought into action in the skin,
by the affections of the other systems. We know that the application
of cold to the sole of the foot frequently produces affections of the
head; that in many cases, the different species of itching, and even of
smarting appear without an injury of the part where the pain is felt.
It is useless to cite examples that are known to all physicians. I will
confine myself to the sympathies of heat and cold alone, which have not
yet been spoken of.
I call by this name the sensation that is experienced upon the skin,
when there is not a superabundance or absence of caloric there. There
is evidently a material cause for the heat in inflammation and for the
cold in the ligature of a great artery. On the contrary, in the cases
of which I spoke, it is but an aberration of the internal sensitive
principle, which resembles that which takes place when we refer the
pain to the extremity of an amputated limb. This is what occurs in many
cases of shivering, in which the internal sensitive principle refers to
the skin a sensation of which the cause does not exist. By approaching
the fire then we do not become warm, because we really were not cold;
but we only destroy by a real sensation, the opposite sensation which
is illusory that we experience, or rather we turn the perception from
this sensation. We know that at the instant of the ejaculation of
semen, a sudden and sympathetic chill often extends over the body.
We know the cold of fear, which almost always arises, like the sweat
produced by this passion, from the sympathetic action exerted upon the
cutaneous organ by an epigastric organ affected by the passion.
Observe what takes place in the beginning of most acute local diseases,
as in those of the serous and mucous surfaces, of the lungs, of
the gastric viscera, &c. &c. The organ which is to be the seat of
the disease is at first affected; immediately many sympathetic and
irregular symptoms arise in all those which are sound; this is the
affection that precedes. When the disease is once developed, and
it follows its periods, a new order is established, as it were, in
the economy. The relations of the organs seem to change. In the
preternatural irregularity of the functions, a kind of regular
assemblage of symptoms is manifested, it is this assemblage which
characterizes the disease and distinguishes it from every other in
which a different order of morbific relations is established between
the functions; now the passage from the natural to the preternatural
relation of functions is marked by a thousand vague symptoms,
which should be attributed to sympathies, and among which appears
particularly the kind of shiver in of which I have spoken.
In the beginning of digestion a kind of sympathetic cold is also
referred to the skin, which is most often as warm as usual; it is
an action exerted by the stomach upon the cutaneous sensibility, an
action from which arises a particular sensation, different no doubt
from that which the same viscus, when disordered, produces in the head,
occasioning head-ache, but which is owing however to the same principle.
The heat is very often sympathetic in the cutaneous organ, less
however, as I have observed, than in the mucous system. We know the
flushes of heat that so often extend over the skin in an irregular
manner, in different fevers, and which are not attended with a greater
disengagement of caloric.
Our modern philosophers will not perhaps be able to understand, how
it is that whilst in the greatest number of cases, the application of
a degree of caloric superior or inferior to that of our temperature,
is necessary to produce heat or cold, this sensation can arise in a
part though it may not have experienced an increase or diminution
of this principle. But in the greatest number of cases has not pain
a material cause? And yet all sympathies produce it without this
cause. The vulgar, who stop at the diversity of the modifications
of feeling, believe that an insulated principle presides over each.
Let us disregard all these modifications, in order to see but a
single principle in the irregularities as in the regular course of
sensibility. That this property, sympathetically altered, gives us
the sensation of heat or cold as in the skin, of pulling as in the
nerves, of lassitude as in the muscles in the beginning of a disease,
&c.; these are but varieties of a single cause, one, of which we are
ignorant, but which evidently exists. In general, the sympathies of
animal sensibility put into action in each system the sensation which
is usual there. The sympathy which, acting upon the skin, creates there
a sensation of heat or of cold, would have produced that of lassitude
if it had acted upon a muscle.
In order to form an exact idea of heat and cold considered as
sensations, let us recollect that they may arise from different causes.
1st. From the increase or diminution of the caloric of the atmosphere.
2d. From the disengagement or the want of disengagement of this fluid
in a part of the economy, as in a phlegmon or after the ligature of
an artery of a limb. 3d. Sometimes without previous inflammation more
caloric is disengaged in the whole body; there is a general increase of
temperature; we then feel an internal and external heat; or caloric is
disengaged locally in a part of the skin, and the patient feels a heat
there as he does who applies his hand upon this place. 4th. Finally,
there are sympathies of heat and cold. Some other parts, besides the
mucous surfaces and the skin, feel these sympathies; we know the
sensation of coldness that is felt to arise from the abdomen to the
thorax, &c.
The organic properties of the skin are also frequently put into action
by sympathies. The sweat on the skin is suppressed in a moment, if a
cold body is taken into the stomach. The entrance of teas into this
viscus, and an increased cutaneous exhalation, are two phenomena that
take place almost at the same instant; so that we cannot refer the
second to the absorption of the drink, then to its passage into the
black blood through the lungs, and afterwards into the red blood. The
production of sweat is then here analogous to its suppression in the
preceding case; it resembles that of fear, and that of phthisis in
which the lungs being affected act upon the skin. Shall I speak of
the innumerable varieties of this organ in diseases, of its dryness,
its moisture, its copious sweats, &c. phenomena for the most part
sympathetic, and which arise from the relations which connect this
sound organ with the diseased parts? I have pointed out those which
exist between it and the mucous surfaces. The membrane of the stomach
is the one with which it especially sympathizes. The digestive
phenomena are a proof of this. It would be necessary to treat of all
diseases in order to speak of the sympathetic influences exerted upon
the skin. These influences are often chronic. How in many organic
diseases, do different tumours form upon the skin? Precisely as
petechiæ, miliary eruptions, &c. are produced in acute fevers; the
difference is only in the duration of the sympathetic phenomena.
Animal and sensible organic contractility cannot be evidently put into
action in the passive sympathies of the skin, since it is not endowed
with these properties.
_Active Sympathies._
The four classes of cutaneous affections of which we have spoken,
occasion many sympathetic phenomena, the following are some of them.
1st. Whenever the papillæ are strongly excited, as in the tickling
of very sensitive people, various organs feel it sympathetically;
sometimes it is the heart; hence the syncopes that then take place;
sometimes it is the stomach; thus I knew two persons who could be made
to vomit by tickling them; sometimes it is the brain, as when in very
irritable people, tickling is carried so far as to produce convulsions,
which is not very rare in nervous women. Who is ignorant of the
influence which the organs of generation receive from the skin, when
stimulated in different parts?
Physicians are often astonished at the extraordinary effects which
some mountebanks produce in the economy, who know how to profit by
their knowledge of the cutaneous sympathies produced by tickling.
But why should we be more astonished at these phenomena, than at
the vomitings produced by an affection of the womb, at the diseases
of the liver arising from an injury of the brain, or at hemicrania
the seat of which is in the gastric viscera? The only difference
is that we can in the first instance, produce to a certain extent
those sympathetic phenomena, which we only observe in the other. Why
do we not oftener make use in medicine of the influence which the
skin when tickled exerts upon the other organs? In hemiplegia, in
adynamic, ataxic fevers, &c. who knows if the excitement of the sole
of the foot, which is so sensible, as every one knows, if that of the
hypochondrium, which is not less so in some people, &c. would not be
better, if repeated ten or twenty times a day, than the application of
a blister, the irritation of which soon passes off? Besides you would
never obtain by a blister, rubefacients, &c. means which act as much
and more upon the organic than the animal sensibility, an effect as
striking, an affection as general in the sensitive system, as by the
tickling of certain parts, a means, which acting only upon this last
species of sensibility, produces phenomena exclusively nervous; whilst
the exhalant system and the capillary with red blood are especially
affected by the others. Certainly there are cases in which one of these
means is preferable to the other. I propose to ascertain these cases.
We have not yet sufficiently analyzed the different kinds of excitement
in diseases; we have not endeavoured to profit enough by what
observation has taught us, upon the sympathies we can produce at will.
Might we not however say, that nature has established certain relations
between very remote organs, that we may be able to make use of these
relations in our means of cure? The charlatan, who employs external
tickling for certain nervous affections, is often more rational,
without knowing it, than the physician with all his pharmaceutical
means.
2d. Whenever the cutaneous exhalants or the external capillary system
from which they arise, are affected in any manner, many other parts
feel it, and this is a second order of the active sympathies of the
skin. Here are referred a great number of phenomena, of which the
following are a part.
A bath which acts upon the skin during digestion, affects
sympathetically the stomach, and disturbs this function. When this
viscus is agitated by spasmodic motions, oftentimes the influence which
it receives from it suddenly calms it, and brings it to its ordinary
state. Not long since in my evening visit at the Hôtel Dieu, I saw a
woman who was vomiting continually from a sudden suppression of her
catamenia. I directed sedatives which were useless. The next evening
she was in the same state; I had her put into a bath; every thing was
calmed the moment she came out of it, and yet the catamenia did not
return. Few organs are more dependant on the skin than the stomach.