dephlogisticated air

Definition

oxygen gas, as originally thought to be air deprived of phlogiston (“the hypothetical fiery principle formerly assumed to be a necessary constituent of combustible bodies and to be given up by them in burning”).

Etymology

From dephlogisticated (“from which the phlogiston has been removed”) + air, coined by the English chemist Joseph Priestley (1733–1804) in a 1775 article entitled “An Account of Further Discoveries in Air” published in the Philosophical Transactions of the Royal Society: see the quotation.

Example Sentences

• "[page 387] As I think I have that ſufficiently proved, the fitneſs of air for reſpiration depends on its capacity to receive the phlogiſton exhaled from the lungs, this ſpecies may not improperly be called, dephlogiſticated air. […] [page 392] Upon the whole, I think, it may ſafely be concluded, that the pureſt air is that vvhich contains the leaſt phlogiſton: […] and that there is a regular gradation from dephlogiſticated air, through common air, and phlogiſticated air, down to nitrous air; […]"
• "[Joseph] Priestley's experiments were performed at intervals from August 1774 till March 1775, and at that date it occurred to him to mix with his dephlogisticated air some nitric oxide over water; absorption took place, and he concluded that he might assume his new air to be respirable."
• "[Joseph] Priestley never swayed from his firm conviction in the phlogiston theory as long as he lived, and he called his new gas ‘dephlogisticated air’."