I could afterwards expel the same air from it,
as from common spirit of salt.

I observed before that this acid vapour, or air, has a strong affinity
with _phlogiston_, so that it decomposes many substances which contain
it, and with them forms a permanently inflammable air, no more liable to
be imbibed by water than inflammable air procured by any other process,
being in fact the very same thing; and that, in some cases, it even
dislodges spirit of nitre and oil of vitriol, which in general appear to
be stronger acids than itself. I have since observed that, by giving it
more time, it will extract phlogiston from substances from which I at
first concluded that it was not able to do it, as from dry wood, crusts
of bread not burnt, dry flesh, and what is more extraordinary from
flints. As there was something peculiar to itself in the process or
result of each of these experiments, it may not be improper to mention
them distinctly.

Pieces of dry _cork wood_ being put to the acid air, a small quantity
remained not imbibed by water, and was inflammable.

Very dry pieces of _oak_, being exposed to this air a day and a night,
after imbibing a considerable quantity of it, produced air which was
inflammable indeed, but in the slightest degree imaginable. It seemed to
be very nearly in the state of common air.

A piece of _ivory_ imbibed the acid vapour very slowly. In a day and a
night, however, about half an ounce measure of permanent air was
produced, and it was pretty strongly inflammable. The ivory was not
discoloured, but was rendered superficially soft, and clammy, tasting
very acid.

Pieces of _beef_, roasted, and made quite dry, but not burnt, absorbed
the acid vapour slowly; and when it had continued in this situation all
night, from five ounce measures of the air, half a measure was
permanent, and pretty strongly inflammable. This experiment succeeded a
second time exactly in the same manner; but when I used pieces of white
dry _chicken-flesh_ though I allowed the same time, and in other
respects the process seemed to go on in the same manner, I could not
perceive that any part of the remaining air was inflammable.

Some pieces of a whitish kind of _flint_, being put into a quantity of
acid air, imbibed but a very little of it in a day and a night; but of
2-1/2 ounce measures of it, about half a measure remained unabsorbed by
water, and this was strongly inflammable, taking fire just like an equal
mixture of