When Was the Phlogiston Theory Discovered?

A former theory of combustion in which all flammable objects were supposed to contain a substance called phlogiston, which was released when the object burned. The existence of this hypothetical substance was proposed in 1669 by Johann Becher, who called it `combustible earth' (terra pinguis: literally 'fat earth').

Who discovered phlogiston?

Beliefs in Chemistry at Lavoisier's Time

Thrown into this mix was the concept of phlogiston. Developed by the German scientist Georg Ernst Stahl early in the 18th century, phlogiston was a dominant chemical concept of the time because it seemed to explain so much in a simple fashion.

How was the phlogiston theory discovered?

The phlogiston theory was discredited by Antoine Lavoisier between 1770 and 1790. He studied the gain or loss of weight when tin, lead, phosphorus, and sulfur underwent reactions of oxidation or reduction (deoxidation); and he showed that the newly discovered element oxygen was always involved.