(1733–1804). A clergyman who at one time was driven from his home because of his liberal politics, Joseph Priestley is remembered principally for his contributions to science. For his best-known accomplishment—the discovery of oxygen—he must share the credit with the Swedish chemist Carl Wilhelm Scheele, who is believed to have made the same discovery somewhat earlier. Priestley announced his find, however, to the French chemist Antoine-Laurent Lavoisier. Lavoisier, realizing that Priestley had isolated an important new element, named it and demonstrated its role in combustion.
Priestley was born on March 13, 1733, near Leeds, Yorkshire, England. He studied for the ministry at Daventry Academy in Northamptonshire, but his unorthodox religious ideas made it easier for him to make his living as a teacher than as a clergyman. He taught at Warrington Academy in Lancashire, where his emphasis on practical education contributed greatly to the school’s success.
In addition to his discovery of oxygen and other gases, Priestley studied electricity and optics. His belief in personal liberty led him to support the French Revolution. He and his family had settled in Birmingham in 1779, but opposition to his unpopular views forced them to leave there in 1791. Three years later he and his wife left England to join their sons in the United States. They settled in Northumberland, Pa., where Priestley died on Feb. 6, 1804.