nd immediately
applying a candle to it.

Acid air not being so manageable as most of the other kinds of air, I
had recourse to the following peculiar method, in order to ascertain its
_specific gravity_. Having filled an eight ounce phial with this air,
and corked it up, I weighed it very accurately; and then, taking out the
cork, I blew very strongly into it with a pair of bellows, that the
common air might take place of the acid; and after this I weighed it
again, together with the cork, but I could not perceive the least
difference in the weight. I conclude, however, from this experiment,
that the acid air is heavier than the common air, because the mouth of
the phial and the inside of it were evidently moistened by the water
which the acid vapour had attracted from the air, which moisture must
have added to the weight of the phial.

SECTION V.

_Of INFLAMMABLE AIR._

It will have appeared from my former experiments, that inflammable air
consists chiefly, if not wholly, of the union of an acid vapour with
phlogiston; that as much of the phlogiston as contributes to make air
inflammable is imbibed by the water in which it is agitated; that in
this process it soon becomes fit for respiration, and by the continuance
of it comes at length to extinguish flame. These observations, and
others which I have made upon this kind of air, have been confirmed by
my later experiments, especially those in which I have connected
_electrical experiments_ with those on air.

The electric spark taken in any kind of _oil_ produces inflammable air,
as I was led to observe in the following manner. Having found, as will
be mentioned hereafter, that ether doubles the quantity of any kind of
air to which it is admitted; and being at that time engaged in a course
of experiments to ascertain the effect of the electric matter on all the
different kinds of air, I had the curiosity to try what it would do with
_common air_, thus increased by means of ether. The very first spark, I
observed, increased the quantity of this air very considerably, so that
I had very soon six or eight times as much as I began with; and whereas
water imbibes all the ether that is put to any kind of air, and leaves
it without any visible change, with respect to quantity or quality, this
air, on the contrary, was not imbibed by water. It was also very little
diminished by the mixture of nitrous air. From whence it was evident,
that it had received an additio