erived from the
alkalies, the earths, and three of the acids, all of which had been
hitherto considered as undecompoundable or simple bodies.

When Sir H. Davy first turned his attention to the effects of the
Voltaic battery, he tried its power on a variety of compound bodies, and
gradually brought to light a number of new and interesting facts, which
led the way to more important discoveries. It would be highly
interesting to trace his steps in this new department of science, but it
would lead us too far from our principal object. A general view of his
most remarkable discoveries is all that I can aim at, or that you could,
at present, understand.

The facility with which compound bodies yielded to the Voltaic
electricity, induced him to make trial of its effects on substances
hitherto considered as simple, but which he suspected of being compound,
and his researches were soon crowned with the most complete success.

The body which he first submitted to the Voltaic battery, and which had
never yet been decomposed, was one of the fixed alkalies, called potash.
This substance gave out an elastic fluid at the positive wire, which was
ascertained to be oxygen, and at the negative wire, small globules of a
very high metallic lustre, very similar in appearance to mercury; thus
proving that potash, which had hitherto been considered as a simple
incombustible body, was in fact a metallic oxyd; and that its
incombustibility proceeded from its being already combined with oxygen.

EMILY.

I suppose the wires used in this experiment were of platina, as they
were when you decomposed water; for if of iron, the oxygen would have
combined with the wire, instead of appearing in the form of gas.

MRS. B.

Certainly: the metal, however, would equally have been disengaged. Sir
H. Davy has distinguished this new substance by the name of POTASSIUM,
which is derived from that of the alkali, from which it is procured.
I have some small pieces of it in this phial, but you have already seen
it, as it is the metal which we burnt in contact with sulphur.

EMILY.

What is the liquid in which you keep it?

MRS. B.

It is naptha, a bituminous liquid, with which I shall hereafter make you
acquainted. It is almost the only fluid in which potassium can be
preserved, as it contains no oxygen, and this metal has so powerful an
attraction for oxygen, that it will not only absorb it from the air, but
likewise from water, or any body whatever