Joseph Priestley

Profession: Chemist, Theologian and Author

Biography: Born into a dissenting family who didn’t confirm to the Church of England, Joseph Priestley remained a influential religious free thinker throughout his whole life and his religious unorthodoxy would play a large part in shaping his scientific inquiries.

Priestley initially became a minister and a teacher, publishing an important book on English Grammar in 1761. He then became interested in electricity and after encouragement from the visiting Benjamin Franklin began experiments on what he considered unanswered questions in the field. Priestley went on to discover 10 new gases including oxygen in 1774 which he called “dephlogisticated air” (now also considered independently co-discovered by Carl Wilhelm Scheele). He was awarded the prestigious Copley Medal as a result in 1773.

While travelling in Paris he met the French chemist Antoine Lavoisier and told him of his discoveries. Lavoisier went on realize the oxygen’s central importance and gave it its name. Priestley disagreed with Lavoisier’s findings and continued to defend his alternative Phlogiston theory.

In 1780 in Birmingham he became part of the Lunar Society, that included potter Josiah Wedgwood. Priestley designed a device to produce carbonated water for the first time in an effort to aid against disease.

Priestley’s support of Unitarianism and support of the French Revolution led to heated opposition toward him in England and in 1791 a mob destroyed his house and he and his family fled to London. He later emigrated to America and settled in Pennsylvania where he lived until his death.

Born: 24 March  1733

Birthplace: Birstall, Yorkshire, England, Kingdom of Great Britain

Died: 6 February 1804 (aged 70)