hat part of the
science which is of late discovery, and is more particularly connected
with chemistry.

It was a trifling and accidental circumstance which first gave rise to
this new branch of physical science. Galvani, a professor of natural
philosophy at Bologna, being engaged (about twenty years ago) in some
experiments on muscular irritability, observed, that when a piece of
metal was laid on the nerve of a frog, recently dead, whilst the limb
supplied by that nerve rested upon some other metal, the limb suddenly
moved, on a communication being made between the two pieces of metal.

EMILY.

How is this communication made?

MRS. B.

Either by bringing the two metals into contact, or by connecting them by
means of a metallic conductor. But without subjecting a frog to any
cruel experiments, I can easily make you sensible of this kind of
electric action. Here is a piece of zinc, (one of the metals I mentioned
in the list of elementary bodies)--put it _under_ your tongue, and this
piece of silver _upon_ your tongue, and let both the metals project a
little beyond the tip of the tongue--very well--now make the projecting
parts of the metals touch each other, and you will instantly perceive a
peculiar sensation.

EMILY.

Indeed I did, a singular taste, and I think a degree of heat: but I can
hardly describe it.

MRS. B.

The action of these two pieces of metal on the tongue is, I believe,
precisely similar to that made on the nerve of a frog. I shall not
detain you by a detailed account of the theory by which Galvani
attempted to account for this fact, as his explanation was soon
overturned by subsequent experiments, which proved that _Galvanism_ (the
name this new power had obtained) was nothing more than electricity.
Galvani supposed that the virtue of this new agent resided in the nerves
of the frog, but Volta, who prosecuted this subject with much greater
success, shewed that the phenomena did not depend on the organs of the
frog, but upon the electrical agency of the metals, which is excited by
the moisture of the animal, the organs of the frog being only a delicate
test of the presence of electric influence.

CAROLINE.

I suppose, then, the saliva of the mouth answers the same purpose as the
moisture of the frog, in exciting the electricity of the pieces of
silver and zinc with which Emily tried the experiment on her tongue.

MRS. B.

Precisely. It does not appear, however, necessary that the flu