hout any sensible effect. We may conclude, therefore, that the
marine acid, in this form of air, is not able to dislodge the other
acids from their union with water.

_Blue vitriol_, which is formed by the union of the vitriolic acid with
copper, turned to a dark green the moment that it was put to the acid
air, which it absorbed, though slowly. Two pieces, as big as small nuts,
absorbed three ounce measures of the air in about half an hour. The
green colour was very superficial; for it was easily wiped or washed
off.

_Green copperas_ turned to a deeper green upon being put into acid air,
which it absorbed slowly. _White copperas_ absorbed this air very fast,
and was dissolved in it.

_Sal ammoniac_, being the union of spirit of salt with volatile alkali,
was no more affected with the acid air than, as I have observed before,
common salt was.

I also introduced to the acid air various other substances, without any
particular expectation; and it may be worth while to give an account of
the results, that the reader may draw from them such conclusions as he
shall think reasonable.

_Borax_ absorbed acid air about as fast as blue vitriol, but without any
thing else that was observable.

Fine white _sugar_ absorbed this air slowly, was thoroughly penetrated
with it, became of a deep brown colour, and acquired a smell that was
peculiarly pungent.

A piece of _quick lime_ being put to about twelve or fourteen ounce
measures of acid air, and continuing in that situation about two days,
there remained one ounce measure of air that was not absorbed by water,
and it was very strongly inflammable, as much so as a mixture of half
inflammable and half common air. Very particular care was taken that no
common air mixed with the acid air in this process. At another time,
from about half the quantity of acid air above mentioned, with much less
quick-lime, and in the space of one day, I got half an ounce measure of
air that was inflammable in a slight degree only. This experiment proves
that some part of the phlogiston which escapes from the fuel, in contact
with which the lime is burned, adheres to it. But I am very far from
thinking that the causticity of quick-lime is at all owing to this
circumstance.

I have made a few more experiments on the mixture of acid air with
_other kinds of air_, and think that it may be worth while to mention
them, though nothing of consequence, at least nothing but negative
conclusions, can be