He used these and similar experiments, all started in 1774, to discredit the phlogiston theory and to prove that the substance discovered by Priestley and Scheele was a chemical element.
Usou estes e outros experimentos similares que comezaron en 1774 para desacreditar a teoría do floxisto e para demostrar que a substancia descuberta por Priestley e Scheele era un elemento químico.