At the instant of death, the muscles remain in two different states;
sometimes they are stiff and inflexible; sometimes they allow the limbs
to execute motions very easily. It is sometimes necessary to make an
effort to bend the thigh of a dead body; at others the least touch is
sufficient to do it, as for example in asphyxia, from charcoal. These
state of rigidity and relaxation have infinite degrees. The first is
sometimes so great, that the subject raised against a wall remains
standing; at other times it is nothing. Some muscles are stiff in
subjects, while others are relaxed. It appears that these different
states depend upon the kind of death, upon the phenomena that accompany
the last moments. But how do they precisely happen? It is an object
of interesting research. I have remarked that the muscles remaining
stiff at the instant of death, are often torn with ease, if we attempt
to force the motions of the limbs to which they go; that the tearing
hardly ever takes place on the contrary in those remaining supple,
whatever may be the impulse communicated at their moveable points; it
is necessary to draw them directly, attach weights to them, &c. to
produce this phenomenon, which is then easy.
The muscular texture is never preternaturally developed in the
different organs in which nature has not originally placed it, as
happens in the osseous, cartilaginous and even fibrous textures. If
it were developed, it would not belong to animal but to organic life;
because in order to depend upon the first, the cerebral nerves are
essentially necessary, the muscle being but the agent of the motions
which the latter communicate.