The phlogiston theory (from the Ancient Greek φλογιστόν phlŏgistón "burning up", from φλόξ phlóx "fire"), first stated in 1667 by Johann Joachim Becher,'s a defunct scientific theory that posited the existence of, in addition to the classical four elements of the Greeks, an additional fire-like element called "phlogiston" that was contained within combustible bodies, and released during combustion. The theory was an… (More on Phlogiston)