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 (§ 30, _h._), and from the bladder in a bottle (§ 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 placed the bottle, inverted, in a vessel with water, and observed the space which the air occupied in it. I found, 14 days afterwards, that the water had not absorbed the smallest quantity of it. (3.) I placed a large bottle, from which the bottom was knocked out, in a deep kettle with water, so that the water outside reached above the top of the bottle. I then tied a bladder, empty of air, over the top of the bottle, and made the water boil up once over the fire. The air which was in that portion of the water contained under the bottle rose into the bladder; and after I had tied up the bladder, and detached it front the bottle, I filled a phial with it, and put a small burning candle into it; it burned there more brightly than in ordinary air.