phlogiston theory

The alchemist and physician J. J. Becher proposed the phlogiston theory.

The phlogiston theory, a superseded scientific theory, postulated the existence of a fire-like element dubbed phlogiston (/flɒˈdʒɪstən, floʊ-, -ɒn/) contained within combustible bodies and released during combustion. The name comes from the Ancient Greek φλογιστόν phlogistón (burning up), from φλόξ phlóx (flame). The idea of a phlogistic substance was first proposed in 1669 by Johann Joachim Becher and later put together more formally in 1697 by Georg Ernst Stahl. Phlogiston theory attempted to explain chemical processes such as combustion and rusting, now collectively known as oxidation. The theory was challenged by the concomitant mass increase and was abandoned before the end of the 18th century following experiments by Antoine Lavoisier in the 1770s and by other scientists. Phlogiston theory led to experiments that ultimately resulted in the identification (c. 1771), and naming (1777), of oxygen by Joseph Priestley and Antoine Lavoisier, respectively.