MSU Gallery of Chemists' Photo-Portraits and Mini-Biographies

Henri-Louis LeChatelier

1850-1936

LeChatelier was first a mining engineer, later a professor of chemistry at the École des Mines (1877), of mineral chemistry at the Collège de France (1898) and finally of chemistry at the Sorbonne (1907). He is best known for his principle regarding systems at equilibrium: if a stress is brought to bear on such a system, a change will occur such that the equilibrium is displaced in a direction which tends to undo the effect of the stress. He became an authority on metallurgy, cements, glasses, fuels and explosives. He developed a platinum-rhodium thermocouple for measuring high temperatures, an optical pyrometer to measure heat by analyzing the light from the heat source, and suggested the use of the oxyacetylene flame for welding and metal cutting.