1-158-908 - Oxford Science Archive/Heritage Images

Lavoisier's investigation of the existence of oxygen in the air, late 18th century, (1894). French chemist Antoine Lavoisier's (1743-1794) experiment to demonstrate the existence of oxygen. Mercury is contained in a trough (right) and in a glass balloon (left). On prolonged heating, some red oxide of mercury was found in the balloon, while the volume of air in the bell jar (right), was reduced.