Let it burn: distinguishing inflammable airs 1766-1790

The issue of the number of species of inflammable air was debated particularly in the period 1777-1786. The work of Henry Cavendish in 1766 and Alessandro Volta in 1777 in characterising two species of inflammable air set the stage for the work of other chemists, particularly in Paris, as they debated this question, mostly concerning heavy inflammable air. Different ways of generating gases were discovered up to 1783, when the synthesis of water and the proposal of carbon as an element created a framework for the question to be answered. In 1785-1786, Claude-Louis Berthollet reported the composition of heavy inflammable air and volatile alkali, while Philippe Gengembre analysed phosphorated hydrogen and hepatic air. In the end, it was the new chemical nomenclature of 1787 that spread their results widely.