The vital properties are also very obscure in them. There is no animal
sensibility in the natural state; it is only when inflammation or some
other cause raises their organic sensibility, a sensibility which their
functions necessarily suppose, it is only then, I say, that the brain
perceives painfully the different irritations of which these organs
are the seat. This becomes manifest, especially when foreign bodies
are formed in the articulations, which suffer from their presence or
are insensible to them, according as they irritate or not by their
position, the cartilaginous extremities. There is neither animal nor
sensible organic contractility in the cartilages; the insensible
organic or tone alone exists in them, and this not in a great degree.
The sympathies are obscure, almost wanting in the cartilaginous system.
I do not know that in the acute affections of the different organs,
we observe sympathetic phenomena of sensibility or contractility in
them. They remain tranquil in the midst of the general derangement
which affects the other systems in this sort of diseases. In chronic
affections even, they experience but little alteration; examine, for
example, comparatively, the body of a man that has died a violent
death, which has left his organs untouched, and that of one who has
died from phthisis, dropsy, cancer, &c. you will perceive between
almost all their organs a striking difference; the aspect of the
muscles, of the mucous and serous surfaces, of the vessels, the nerves,
&c. is entirely changed by the slow alteration they have undergone
in the second; in the midst of these alterations the cartilages are
unchanged, their appearance is almost the same as in a natural state.
_Character of the Vital Properties._
From what has been said, it is evident that the cartilaginous life
can have but little activity, that all the morbid phenomena must
be characterized in these organs by a peculiar slowness, and that
inflammation, for example, must always have in the cartilages, as in
the bones, a chronic progress; this is rendered very clear by the
following experiment. Lay bare a cartilage, divide it, and afterwards
bring it in contact with a portion of a muscle, the skin, &c. also
divided at their surface; the reunion does not take place, or at
least not until a very long time. Why? because the life of the muscle
or the skin being much more active than that of the cartilages, the
inflammation of the first organs will be much more rapid than that
of the second, and consequently the first inflammatory period of one
will correspond to the last of the others. Now the reunion is so much
the easier as the inflammatory periods correspond the more exactly
in the two divided parts that are in contact. Hence why two parts of
the same organ unite much more easily than two surfaces belonging to
different organs. Hence why the greater the analogy in the lives of
the two organs, the greater the facility with which they unite; why
the difficulties increase as the differences of life become greater.
Two osseous surfaces in contact require thirty or forty days to unite;
the two edges of a cutaneous wound unite in two or three days. If you
attempt to render continuous two organs thus unlike in their mode
of cicatrization, by putting them in contact, you will succeed but
slowly. Cover with skin the osseous extremity of an amputated stump;
this will be in a state of suppuration, before the bone has hardly
begun to soften; thus good practitioners have abandoned these pretended
unions by the first intention, so much boasted of, after amputation
by the flap operation. These unions would no doubt take place, if the
life of the organs which enter into the composition of the flap was the
same. But with the diversity of these muscular, osseous, tendinous,
cellular, nervous organs, &c. it requires a long time for all their
lives to be placed as it were in equilibrium, and for these organs to
agglutinate at their divided extremities. I have already observed that
the division of inflammations into acute and chronic gives physicians
an inexact idea; for the duration of the inflammatory phenomena in the
organs is wholly relative to their degree of life. An inflammation
of the cellular texture and of the skin is acute, when it lasts but
a few days; it is chronic when it continues forty or fifty days; in
a cartilage, this last period may be that of an acute inflammation,
whilst a duration of many months is necessary to make it chronic, as
the diseases of the joints exhibit frequent examples.
The natural functions, as well as the morbid affections, have this
slowness of the vital phenomena of the cartilages. The constant
composition and decomposition, which their nutrition supposes, is not
rapid. It requires a long time for nutritive substances to combine
with them. I am persuaded that in animals which die suddenly from the
effects of a carbuncle and whose muscles, glands, membranes, &c. almost
instantly penetrated with the deleterious principles by the nutritive
motion of composition, present an aliment so injurious, I am persuaded,
I say, that these injurious principles not yet having penetrated the
cartilages, these might be digested without danger. It is to the
slowness of the motion of decomposition that must be attributed the
slowness of the resolution of cartilaginous swellings; for tumours are
resolved by the same laws that decompose our organs, as they are formed
by the same laws that preside over their composition.
The cartilages and the analogous organs, are to the other parts of the
economy, as it respects their vitality, what the zoophytes and other
animals with a capillary circulation only, are to the animals better
organized, to those with a general circulation and those that have a
heart with a double ventricle. As much as life considered in general
in the series of beings that it animates, presents a difference in
its activity, so much it differs in the same respect, examined in
particular in the organs of each of these beings.