ed associations acquaints us
with those motions of tangible bodies, which depend on their elasticity;
and which we had before learned by our sense of touch.

V. _Of Smell and of Taste._

The objects of smell are dissolved in the fluid atmosphere, and those of
taste in the saliva, or other aqueous fluid, for the better diffusing them
on their respective organs, which seem to be stimulated into animal motion
perhaps by the chemical affinities of these particles, which constitute the
sapidity and odorosity of bodies with the nerves of sense, which perceive
them.

Mr. Volta has lately observed a curious circumstance relative to our sense
of taste. If a bit of clean lead and a bit of clean silver be separately
applied to the tongue and palate no taste is perceived; but by applying
them in contact in respect to the parts out of the mouth, and nearly so in
respect to the parts, which are immediately applied to the tongue and
palate, a saline or acidulous taste is perceived, as of a fluid like a
stream of electricity passing from one of them to the other. This new
application of the sense of taste deserves further investigation, as it may
acquaint us with new properties of matter.

From the experiments above mentioned of Galvani, Volta, Fowler, and others,
it appears, that a plate of zinc and a plate of silver have greater effect
than lead and silver. If one edge of a plate of silver about the size of
half a crown-piece be placed upon the tongue, and one edge of a plate of
zinc about the same size beneath the tongue, and if their opposite edges
are then brought into contact before the point of the tongue, a taste is
perceived at the moment of their coming into contact; secondly, if one of
the above plates be put between the upper lip and the gum of the
fore-teeth, and the other be placed under the tongue, and their exterior
edges be then brought into contact in a darkish room, a flash of light is
perceived in the eyes.

These effects I imagine only shew the sensibility of our nerves of sense to
very small quantities of the electric fluid, as it passes through them; for
I suppose these sensations are occasioned by slight electric shocks
produced in the following manner. By the experiments published by Mr.
Bennet, with his ingenious doubler of electricity, which is the greatest
discovery made in that science since the coated jar, and the eduction of
lightning from the skies, it appears that zinc was always found minus, and
s