It follows from what I have said, that whenever the organic sensibility
of the absorbents is altered in any way, absorption must necessarily
experience a corresponding derangement; now this is what constantly
happens. Serum often bathes for whole months the absorbent orifices,
in dropsy, without raising their sensibility sufficiently to be taken
up by them. Let any cause increase this property, instantly absorption
takes place. Observe some indolent tumours which remain for a long
time in the same state by the stagnation of their fluids, they are
immediately discussed when certain medicines applied to them rouse the
dormant sensibility of their absorbents. Discutients do not act upon
the fluids themselves; they do not attenuate, or cut them, according
to the vague language of physicians, but by changing the degree of
force of the absorbents, they render them able to act. It is so true
that it is in this way that different resolutions are effected, that
often a slight degree of inflammation is previously necessary to their
development; all surgeons know this. Desault did not consider most of
the swellings of the testicles as an obstacle to the operation for
hydrocele by injection. On the contrary it often happened, that after
the irritation produced in the testicles by the surrounding membrane,
the enlargement disappeared, which was only kept up by the want of
energy in the absorbents.
The alterations of organic sensibility can diminish, increase, or
variously modify this property. Let us cease to wonder then at the
extreme variety of the absorptions; let us not be astonished, if many
fluids, besides those ordinarily taken up, can pass into the blood
by the absorbents; if the bile, the urine, the mucous fluids, which
are usually rejected, can enter the circulation; if the blood effused
in the cellular texture is taken up by these vessels. The forces of
life impress, by their extreme variety, the same character on all the
functions over which they preside.
Much has been said of putrid matters passing into the blood, and there
serving as a cause for diseases. This infection of the blood has
undoubtedly been exaggerated; but I am convinced that in many cases it
is real. Why are the colour, consistence, odour, and nature of the
excrements so very variable? If the same substances are always absorbed
from the aliments, it is evident that the residue of these aliments
would always be the same. Observe the innumerable varieties of the
urine, the bile, the mucous fluids, &c. according to the difference
of the principles that concur to form them. Why should not the chyle
present the same variations? it would be the only fluid of its kind
in the animal economy if it did not change under many circumstances.
Now, whence can these changes come, if not from this, that the lacteals
present numberless varieties in their organic sensibility, varieties,
each of which admits only certain principles and rejects the others?
The absorption of the lacteals, which, in an ordinary state, introduces
into the blood only nutritive substances, can then often be a way open
for the admission of many morbific principles. Thus in the lungs, the
vessels which take from the air the substances proper to colour the
blood, often draw in principles injurious to their functions, according
to the different alterations that their sensibility can experience.
In the ordinary state, the kind of organic sensibility and of tone of
the cutaneous and mucous absorbents, shuts out all external substances
that are hurtful. But when this kind is changed, the way can in an
instant be open to them. Does not pus remain without mischief on the
cellular texture, in most wounds? Let an imprudent application raise
there a little the forces of the absorbents, it is taken up by them;
the ulcer dries up; the pus passes into the blood; and then follows the
whole sad train of the symptoms of re-absorption which commences.
We can say, that a thousand channels are incessantly open in our
organs, to morbific principles. The organic sensibility, placed as a
sentinel at their mouths, indicates according to the manner in which
it is affected, to the insensible contractility when it is necessary to
open or shut them.
It is exhalation that contributes to the formation of most tumours; it
is absorption that serves for their cure.
If I were to run over the phenomena of absorption in the different
ages, sexes, seasons and climates, I could show constantly the
differences of organic sensibility always preceding the differences of
this function. I shall speak of them in the different ages.
The causes that vary the natural type of the sensibility of the
absorbents, are, as in all the other functions, direct or sympathetic;
1st, direct, as when by previous friction on the skin, we excite the
absorbents, and force them to act, which they would not have done
without this; 2d, sympathetic, as when the absorbents, feeling the
affection of a distant viscus, increase or diminish their action,
according to the kind of influence they receive. We have spoken of this
phenomenon in the sympathies of the different systems.