Oxygen Oxygen, symbol O, colorless, odorless, tasteless, slightly magnetic gaseous element. On earth, oxygen is more abundant than any other element. Oxygen was discovered in 1774 by the British chemist Joseph Priestley and, independently, by the Swedish chemist Carl Wilhelm Scheele; it was shown to be an elemental gas by the French chemist Antoine Laurent Lavoisier in his classic experiments on combustion. Large amounts of oxygen are used in high-temperature welding torches, in which a mixture of oxygen and another gas produces a flame of much higher temperature than is obtained by burning gases in air. Oxygen is administered to patients whose breathing is impaired and also to people in aircraft f