William Cullen

William Cullen was a Scottish physician and chemist, born April 15, 1710 in Hamilton, South Lanarkshire and died February 5, 1790 in Edinburgh, whose chemistry lectures produced the earliest documented demonstration of artificial refrigeration. A leading figure of the Scottish Enlightenment who taught at the University of Glasgow and later the University of Edinburgh, he showed in 1748 that the rapid evaporation of ethyl ether under reduced pressure produces a marked cooling effect, laying the physical basis that later refrigeration machinery would exploit, and in 1756 he gave the first documented public demonstration of artificial cooling from that principle, though he never developed the effect into a practical machine himself. Cullen's main career was in medicine: he served as president of the Royal College of Physicians and Surgeons of Glasgow in 1746 and 1747, as first physician to the king in Scotland from 1773, and as a founding member of the Royal Society of Edinburgh in 1783, and his widely used textbook First Lines of the Practice of Physic and his lectures shaped a generation of physicians, including his students Joseph Black, Benjamin Rush and William Withering.