OXYGENE, a term adopted in the new chemical
nomenclature to express the acidifying principle; from
the "acid," and γενειναι "to generate." It is not
found naturally in a separate state, but always combined
or mixed with some other substance. In its aeriform
or elastic state, it is called by the French chemists oxy-
genous gas, and is the same as the dephlogisticated air of
Priestley.
Priestley and Cavendish, the empyreal air of Scheele, the vital air and pure air of other modern chemists. It was called dephlogisticated by the followers of Stahl's doctrine, who imagined it to be air deprived of phlogiston; the epithet of empyreal was given to it by Mr Scheele, who first discovered it to be the only constituent part of the atmosphere which contributes to support inflammation or combustion. He made many curious experiments on inflammation, and was the first who completely analysed common air, showing it to consist of 27 parts of empyreal, 72 of soul, and 1 of fixed air. He found, that these 27 parts only were consumed by a burning body; and that these, during the act of combustion, were united and combined with the inflammable body burnt in them, so as to form a compound no longer combustible. Lavoisier extending these experiments, found that the body, thus produced by empyreal air, being combined with the matter of the inflammable body burnt in it, was, in many cases, an acid; in consequence of which property, he gave this air the name of oxygen, i. e. "the generator of acidity." He was perhaps too hasty in adopting this name; for the same air is found in combination with inflammable matter, forming compounds that are by no means acid, of which we shall content ourselves with producing only one example, namely water, which is the compound resulting from the combination of this air with inflammable air. See WATER.
Common atmospheric air was found by Scheele to promote animal life in a manner somewhat similar to its promoting combustion. He extended his experiments to this subject also; and he concludes, that this empyreal air is the only part of the atmosphere which is capable of supporting animal life, and that no animal can exist a minute without it. In consequence of this property it has been called vital air. Since, however, it is absolutely necessary for the support both of combustion and of animal life, and since neither of these can exist without it, both the terms empyreal and vital are deficient, expressing only certain properties of this elastic fluid (which may be also said of the word oxygen); and hence some later chemists have suggested the propriety of designating it by the name of pure air. See COMBUSTION, INFLAMMATION, CHEMISTRY, AIR, WATER.