The peculiar cartilaginous texture exhibits an interlacing of fibres so
compact, that it appears at first view homogeneous, formed into a mass
of gelatine, without order and without any particular direction. Yet
with a little attention we distinguish longitudinal fibres, which are
crossed by transverse and oblique ones.
These fibres are more apparent in the cartilages of the moveable
osseous extremities than in the others. They have infinitely less
suppleness than the fibres of the fibro-cartilaginous substances; thus
these bend without breaking, whilst the first break when they are
bent considerably; the place of the rupture is smooth, with but few
inequalities.
The cartilaginous texture is remarkable for many characters which
distinguish it from the others. Next to the osseous texture, no one so
long resists putrefaction and maceration. In the midst of a dead body
wholly putrid, we find this texture almost untouched, preserving its
appearance, its structure, and even oftentimes its natural whiteness.
The same thing is frequently seen in gangrenous limbs in the living
body. I have kept cartilaginous substances a very long time in water,
which have not become altered, except a little in their colour. It
would require more than a year perhaps, to reduce them to that soft,
mucous, liquid pulp, to which maceration reduces most of the organs.
The cartilaginous texture contracts under the very powerful action
of caloric, like all the other textures; yet this phenomenon is not
apparent in the thyroid cartilage on account of its thickness, nor in
the cartilages that encrust the bones, on account of their adhesion
to these bones. But if we cut one in fine layers, and the others in
slices, and plunge them into boiling water, they crisp up immediately
and with force.
Exposed to drying, the cartilaginous texture becomes yellow, acquires
a semi-transparency analogous to that of the tendons and dried
ligaments; it becomes hard, contracts, diminishes in size, and loses
its elasticity as it becomes hard.
Ebullition also gives it at first a yellow colour, then it cracks it
upon the articular extremities, breaks it in different places, and
raises it by layers which it softens, and which finally it melts almost
completely to a small residue, which does not appear to be gelatinous.
The softening of the cartilaginous texture renders it much more fit to
be dissolved by the digestive juices than it naturally is. Swallowed
raw, the cartilages would remain a long time in the stomach, whilst
they are very easily digested when cooked; this is one of the very
great advantages of the boiling of meat. In different experiments made
upon digestion, I have found portions of cartilages still untouched in
the stomach of dogs, whilst the flesh was already reduced to a pulp.
In certain cases, the cartilaginous texture is singularly altered.
In the diseases of the articulation of the hip, it assumes an aspect
wholly different; it is a soft substance, like lard, with very distinct
vessels, sometimes with very evident fibres, having a size double,
quadruple what is natural, and filling the cotyloid cavity. I have
observed that then they do not become yellow, do not melt by ebullition
and consequently are not gelatinous. In the same diseases, I have
found the cartilaginous texture, upon the femur and the ilium, not
only ossified, but changed into a substance exactly like ivory; I have
preserved these two pieces.
When the cartilages become osseous, there is developed in their middle
a texture analogous to that of the texture of the cells of the bones,
in which the interlaced fibres leave between them very distinct spaces,
and in which is deposited a kind of medullary fluid. This observation
is especially applicable to those of the cavities, of the larynx, of
the thorax, &c.