Georg Ernst Stahl. Image provided by Edgar Fahs Smith Collection, University of Pennsylvania Library.		The rise and fall of phlogiston Georg Ernst Stahl (1660–1734) formulated the first theory explaining combustion. Stahl held that metals and combustible materials contained a substance called phlogiston, which was released when the metal calcified or the fuel burned. The theory stood several decades before being overturned by Antoine-Laurent Lavoisier.