Antoine-Laurent LavoisierDied 8 May 1794 at age 50 (born 26 Aug 1743). French chemist, the “father of modern chemistry,” was a brilliant experimenter also active in public affairs. An aristocrat, he invested in a private company hired by the government to collect taxes. With his wealth he built a large laboratory. In 1778, he found that air consists of a mixture of two gases which he called oxygen and nitrogen. By studying the role of oxygen in combustion, he replaced the phlogiston theory. Lavoisier also discovered the law of conservation of mass and devised the modern method of naming compounds, which replaced the older nonsystematic method. During the French Revolution, for his involvement with tax-collecting, he was guillotined. |