itiated air? Mr. Priestley indeed
has accomplished this, but it did not succeed with me however much I
also wished it. He has converted aerial acid into wholesome air by means
of a mixture of iron filings, sulphur, and some water. When I desired to
repeat this experiment, the aerial acid was always absorbed by the iron
filings. I likewise powdered finely some iron filings which had been
fused together with excess of sulphur, moistened this with water, and
preserved it in a bottle which was filled with aerial acid: but with the
same result. After 2 two days the aerial acid was almost entirely
absorbed. This philosopher also says that he has made vitiated air
wholesome again by agitation with water. I must admit, however, that
with me this likewise failed. I filled a flask one fourth part with
vitiated air, and the remainder with fresh water; I closed the flask
very tightly, and shook it up and down for almost a whole hour. Then
when I collected this air in a bladder, and from this in a bottle, I
found that the candle was extinguished afterwards as it was before. He
mixed with water, by agitation, the inflammable air from metals; this
also would not succeed with me, although I used only little inflammable
air, and much water. He also observed that plants made vitiated air
wholesome again. It follows from my experiments that they vitiate air. I
kept plants, in the dark as well as exposed to sunlight, in a flask
which was filled with vitiated air and carefully secured (which careful
securing must really be attended to). I tested a little of this air
every 2 days, and always found it vitiated.

+94.+ Water has the peculiar property of separating the proximate
constituents of air; of uniting with fire-air; and of entering into no
kind of union with vitiated air. (1.) I filled a large bottle with
boiled water which had been cooled shortly before, and permitted the
tenth part to run out. I then placed the bottle, inverted and open, in a
vessel with water. I observed the quantity of air to diminish a little
every day, and when this diminution ceased, I collected the remaining
air first in a bladder (Sec. 30, _h._), and from the bladder in a bottle (Sec.
30, _c._), and brought a burning candle into the bottle; it had scarcely
reached the mouth when it went out. (2.) I then took the same kind of
water freed from air, filled a bottle with it, and permitted the tenth
part of it to run into a bladder filled with vitiated air. I next