further from each other; and lastly,
withdraw the rubbed glass-tube, and the skewer X will now be found to
possess resinous electricity, which has been generally called negative
or minus electricity; and the skewer Y will be found to possess
vitreous, or what is generally termed positive or plus electricity.

The same phenomenon will occur if rubbed sealing wax be applied near
to, but not in contact with, the skewer X, as the skewer X will then
be left with an atmosphere of vitreous ether, and the skewer Y with
one of resinous ether. These experiments also evince the existence of
two electric fluids, as they cannot be understood from an idea of one
being a greater or less quantity of the same material; as a vacuum of
electric ether, brought near to one end of the skewer, cannot be
conceived so to attract the ether as to produce a vacuum at the other
end.

In this experiment the electric atmospheres, which are nearly of
similar kinds, do not seem to touch, as there may remain a thin plate
of air between them, in the same manner as small globules of mercury
may be pressed together so as to compress each other, long before they
intermix; or as plates of lead or brass require strongly to be pressed
together before they acquire the attraction of cohesion; that is,
before they come into real contact.

2. It is probable, that all bodies are more or less perfect
conductors, as they have less or more of either of the electric ethers
combined with them; as mentioned in Preliminary Proposition, No. VI.
as they may then less resist the passage of either of the ethers
through them. Whence some conducting bodies admit the junction of
these spontaneous electric atmospheres, in which the proportions or
quantities of the two ethers are not very different, with greater
facility than others.

Thus in the common experiments, where the vitreous or resinous ether
is accumulated by art, metallic bodies have been esteemed the best
conductors, and next to these water, and all other moist bodies; but
it was lately discovered, that dry charcoal, recently burnt, was a
more perfect conductor than metals; and it appears from the
experiments discovered by Galvani, which have thence the name of
Galvanism, that animal flesh, and particularly perhaps the nerves of
animals, both which are composed of much carbon and water, are the
most perfect conductors yet discovered; that is, that they give the
least resistance to the junction of the spontaneous