The German chemist and medical theorist Georg Ernst Stahl (1660-1734) was the founder of the phlogiston theory of combustion and the author of a theory of medicine based upon vitalistic ideas.

Georg Stahl was born on Oct. 21, 1660, at Anspach in Bavaria, the son of a Lutheran pastor. Although brought up in an extremely pious and religious household, he early showed an enthusiasm for chemistry. By the age of 15 he had mastered a set of university lecture notes on the subject as well as a difficult treatise by Johann Kunckel.

Stahl studied medicine at the University of Jena, where he graduated in 1683. Here he came under the influence of iatrochemical theories, which gave an interpretation of physiological processes in terms of chemistry. He was later to become a strong opponent of this school of medical theory. Following graduation he taught at the University of Jena for 10 years.

In 1694 Stahl...