1911 Encyclopædia Britannica/Prout, William
PROUT, WILLIAM (1785–1850), English chemist and physician, was born in Horton, Gloucestershire, on the 15th of January 1785, and died at London on the 9th of April 1850. His life was spent as a practising physician in London, but he also occupied himself with chemical research. He was an active worker in physiological chemistry, and carried out many analyses of the products of living organisms, among them being one of the gastric juice which, at the end of 1823, resulted in the notable discovery that the acid contents of the stomach contain hydrochloric acid which is seperable by distillation. In 1815 he published anonymously in the Annals of Philosophy a paper “On the relation between the specific gravities of bodies in their gaseous state and the weights of their atoms,” in which he calculated that the atomic weights of a number of elements are multiples of that of hydrogen; and in a second paper published in the same periodical the following year he suggested that the πρώτη ὕλη of the ancients is realized in hydrogen, from which the other elements are formed by some process of condensation or grouping. This view, generally known as “Prout’s hypothesis,” at least had the merit of stimulating inquiry, and many of the most careful determinations of atomic weights undertaken since its promulgation have been provoked by the desire to test its validity.