s?

MRS. B.

This jar is full of that acid in its gaseous state--it is inverted over
mercury instead of water, because, being absorbable by water, this gas
cannot be confined by it. --I shall now raise the jar a little on one
side, and suffer some of the gas to escape. --You see that it
immediately becomes visible in the form of a cloud.

EMILY.

It must be, no doubt, from its uniting with the moisture of the
atmosphere, that it is converted into this dewy vapour.

MRS. B.

Certainly; and for the same reason, that is to say, its extreme
eagerness to unite with water, this gas will cause snow to melt as
rapidly as an intense fire.

This acid proved much more refractory when Sir H. Davy attempted to
decompose it than the other two undecompounded acids. It is singular
that potassium will burn in muriatic acid, and be converted into potash,
without decomposing the acid, and the result of this combustion is a
_muriat of potash_; for the potash, as soon as it is regenerated,
combines with the muriatic acid.

CAROLINE.

But how can the potash be regenerated if the muriatic acid does not
oxydate the potassium?

MRS. B.

The potassium, in this process, obtains oxygen from the moisture with
which the muriatic acid is always combined, and accordingly hydrogen,
resulting from the decomposition of the moisture, is invariably evolved.

EMILY.

But why not make these experiments with dry muriatic acid?

MRS. B.

Dry acids cannot be acted on by the Voltaic battery, because acids are
non-conductors of electricity, unless moistened. In the course of a
number of experiments which Sir H. Davy made upon acids in a state of
dryness, he observed that the presence of water appeared always
necessary to develop the acid properties, so that acids are not even
capable of reddening vegetable blues if they have been carefully
deprived of moisture. This remarkable circumstance led him to suspect,
that water, instead of oxygen, may be the acidifying principle; but this
he threw out rather as a conjecture than as an established point.

Sir H. Davy obtained very curious results from burning potassium in a
mixture of phosphorus and muriatic acid, and also of sulphur and
muriatic acid; the latter detonates with great violence. All his
experiments, however, failed in presenting to his view the basis of the
muriatic acid, of which he was in search; and he was at last induced to
form an opinion respecting the nature of this acid, which