Oxygen

(pks’ ’-e-jen) [b^’vg, acid; yevvav, to produce]. A colorle , tastele , odorle gas, one of the nonmetallic elements, having an atomic weight of 15.96; quantivalence II; symbol O; and constituting one-fifth of the atmosphere, eight-ninths of water, three fourths of organized bodies, and about one half the crust of the globe; it supports combustion, and is e ential to the respiration of animals and plants. It combines with most elements, its combination with the nonmetallic substances giving rise to acids (oxyacids). In medicine it has been employed by inhalation in the treatment of pneumonia, pulmonary tuberculosis, grave anemias, asphyxia, and poisoning by opium. 471