( 1733–1804), English scientist and theologian. Priestley was the author of about 150 books, mostly theological or educational. His chief work was on the chemistry of gases, in which his most significant discovery was of ‘dephlogisticated air’ (oxygen) in 1774; he demonstrated that it was important to animal life, and that plants give it off in sunlight.
Definition of Priestley, Joseph in:
- The US English dictionary