it be considered that the proper nourishment of an animal
body, from which the source and materials of all muscular motion must be
derived, is probably some modification of phlogiston. Nothing will
nourish that does not contain phlogiston, and probably in such a state
as to be easily separated from it by the animal functions.

That the source of muscular motion is phlogiston is still more probable,
from the consideration of the well known effects of vinous and
spirituous liquors, which consist very much of phlogiston, and which
instantly brace and strengthen the whole nervous and muscular system;
the phlogiston in this case being, perhaps, more easily extricated, and
by a less tedious animal process, than in the usual method of extracting
it from mild aliments. Since, however, the mildest aliments do the same
thing more slowly and permanently, that spirituous liquors do suddenly
and transiently, it seems probable that their operation is ultimately
the same.

This conjecture is likewise favoured by my observation, that respiration
and putrefaction affect common air in the same manner, and in the same
manner in which all other processes diminish air and make it noxious,
and which agree in nothing but the emission of phlogiston. If this be
the case, it should seem that the phlogiston which we take in with our
aliment, after having discharged its proper function in the animal
system (by which it probably undergoes some unknown alteration) is
discharged as _effete_ by the lungs into the great common _menstruum_,
the atmosphere.

My conjecture suggested (whether supported or not) by these facts, is,
that animals have a power of converting phlogiston, from the state in
which they receive it in their nutriment, into that state in which it is
called the electrical fluid; that the brain, besides its other proper
uses, is the great laboratory and repository for this purpose; that by
means of the nerves this great principle, thus exalted, is directed into
the muscles, and forces them to act, in the same manner as they are
forced into action when the electric fluid is thrown into them _ab
extra_.

I farther suppose, that the generality of animals have no power of
throwing this generated electricity any farther than the limits of their
own system; but that the _torpedo_, and animals of a similar
construction, have likewise the power, by means of an additional
apparatus, of throwing it farther, so as to affect other animals, and