Charles Blagden

Sir Charles Blagden (1748 to 1820) was an English physician and chemist, born at Wotton-under-Edge in Gloucestershire. He studied medicine at the University of Edinburgh and graduated as a doctor in 1768, was elected a fellow of the Royal Society in 1772, and served as an army surgeon from 1776 to 1780, including on the hospital ship HMS Pigot during the American War of Independence. From about 1783 he was assistant to Henry Cavendish, and in June of that year he visited Antoine Lavoisier in Paris and described how Cavendish had made water by burning inflammable air, an account that helped lead Lavoisier to his concept of a chemical reaction. Blagden showed that people can withstand room temperatures as high as 127 degrees Celsius and was the first Western scientist to recognise the role of perspiration in thermoregulation. His experiments on dissolved salts led to Blagden's Law, that the freezing point of a solution falls in proportion to its concentration. He was Secretary of the Royal Society from 1784 to 1797, won its Copley Medal in 1788, was knighted in 1792 and died at Arcueil in France.