oxygen

(oks’ij-en) [Gr. ὀξύς sour + γεννᾶν to produce]. A gaseous element existing free in the air and in combination in most non-elementary solids, liquids, and gases; symbol, Oxygen constitutes 20 per cent. by weight of the atmospheric air; it is the e ential agent in the respiration of plants and animals, and is nece ary to support combustion. It forms the characteristic constituent of most acids. It is administered chiefly in pulmonary diseases and anemia, mainly by inhalation.