Black, Joseph

Black, Joseph (chemist) (1728-1799), British chemist, best known for his detailed account of the isolation and chemical activity of carbon dioxide. Black was born in Bordeaux, France, and educated at the universities of Glasgow and Edinburgh in Scotland. He was professor of chemistry, medicine, and anatomy at the University of Glasgow from 1756 to 1766; thereafter he was professor of chemistry at the University of Edinburgh. In about 1761 Black discovered the phenomenon of latent heat, and three years later he measured the latent heat of steam. His pupil and assistant James Watt later put these discoveries to practical use when he made improvements to the early steam engine. About 1754 Black discovered carbon dioxide, a gas which he called fixed air, and showed its function in the causticization of lime (making lime more alkaline), thus helping to disprove the phlogiston theory of combustion. He also discovered that different substances have different heat capacities.