4 - Antoine Lavoisier and Joseph Priestley Both Test the Befuddling Phlogiston Theory: Junking a Confusing Hypothesis May Be Necessary to Clear the Way for New and Productive Science

Abstract

Phlogiston theory was a stage in the development of the theory of combustion more sophisticated than the “four-element” theory of the ancient Greeks. Although it could explain the smelting of iron from its oxide and the combustion of charcoal, it had many fatal flaws. Its proponents held onto it long after it had been successfully falsified. Joseph Priestley’s brilliant experiments verified that “respirable air” was the constituent of “common air” associated with combustion, but he could never abandon the phlogiston theory. It took the iconoclastic genius of Antoine Lavoisier to demonstrate that oxygen was itself an element.