t in the minds of the persons, whom we commiserate or
congratulate?

There are certain concurrent or successive actions of some of the glands,
or other parts of the body, which are possessed of sensation, which become
intelligible from this propensity to imitation. Of these are the production
of matter by the membranes of the fauces, or by the skin, in consequence of
the venereal disease previously affecting the parts of generation. Since as
no fever is excited, and as neither the blood of such patients, nor even
the matter from ulcers of the throat, or from cutaneous ulcers, will by
inoculation produce the venereal disease in others, as observed by Mr.
Hunter, there is reason to conclude, that no contagious matter is conveyed
thither by the blood-vessels, but that a milder matter is formed by the
actions of the fine vessels in those membranes imitating each other. See
Section XXXIII. 2. 9. In this disease the actions of these vessels
producing ulcers on the throat and skin are imperfect imitations of those
producing chanker, or gonorrhoea; since the matter produced by them is not
infectious, while the imitative actions in the hydrophobia appear to be
perfect resemblances, as they produce a material equally infectious with
the original one, which induced them.

The contagion from the bite of a mad dog differs from other contagious
materials, from its being communicable from other animals to mankind, and
from many animals to each other; the phenomena attending the hydrophobia
are in some degree explicable on the foregoing theory. The infectious
matter does not appear to enter the circulation, as it cannot be traced
along the course of the lymphatics from the wound, nor is there any
swelling of the lymphatic glands, nor does any fever attend, as occurs in
the small-pox, and in many other contagious diseases; yet by some unknown
process the disease is communicated from the wound to the throat, and that
many months after the injury, so as to produce pain and hydrophobia, with a
secretion of infectious saliva of the same kind, as that of the mad dog,
which inflicted the wound.

This subject is very intricate.--It would appear, that by certain morbid
actions of the salivary glands of the mad dog, a peculiar kind of saliva is
produced; which being instilled into a wound of another animal stimulates
the cutaneous or mucous glands into morbid actions, but which are
ineffectual in respect to the production of a similar contagiou