The former experiment had been performed by Scheele and Priestley, who had named the gas " phlogisticated air "; Lavoisier subsequently named it oxygen, regarding it as the " acid producer " (OE, sour).
Chemical literature was full of the phlogistic modes of expression - oxygen was '" phlogisticated air," nitrogen " dephlogisticated air," &c. - and this tended to retard its promotion.
I therefore made an experiment to determine whether the whole of a given portion of the phlogisticated air of the atmosphere could be reduced to nitrous acid, or whether there was not a part of a different nature to the rest which would refuse to undergo that change.
I then, in order to decompound as much as I could of the phlogisticated air [nitrogen] which remained in the tube, added some dephlogisticated air to it and continued the spark until no further diminution took place.
Having by these means condensed as much as I could of the phlogisticated air, I let up some solution of liver of sulphur to absorb the dephlogisticated air; after which only a small bubble of air remained unabsorbed, which certainly was not more than of the bulk of the dephlogisticated air let up into the tube; so that, if there be any part of the dephlogisticated air of our atmosphere which differs from the rest, and cannot be reduced to nitrous acid, we may safely conclude that it is not more than 7a part of the whole."