Phlogist

Part of speech: noun

Definitions

1. A natural philosopher or chemist who subscribed to the theory that all combustible materials contain an invisible substance called phlogiston
2. A scientist of the pre-modern era who explained fire and combustion through the presence of phlogiston within burning matter
3. An adherent of the phlogiston theory, a now-discredited chemical framework that dominated understanding of combustion before oxidation theory

Etymology: Phlogiston was the name chemists gave to an invisible substance they believed every flammable material contained and released when it burned. The theory was put forward by the German chemist Johann Joachim Becher in the 1660s and was refined by Georg Ernst Stahl around 1700, who gave it its name. The word itself comes from the Greek "phlogistos," meaning "burned up" or "inflammable," from "phlogizein," "to set on fire." The idea was taken seriously for about a century. Burning wood was thought to release phlogiston into the air, leaving behind ash that was lighter and more "dephlogisticated." Antoine Lavoisier's experiments in the 1770s showed that combustion actually involves combining with oxygen, which gained weight rather than losing it, and the theory was abandoned.