Priestley, Joseph. Natural philosopher. Born in 1733. Gained the Copley Medal in 1773 for his discoveries concerning the properties of fixed air, and was librarian to Lord Shelburn for seven years. He also made important observations on respiration. In 1791, his house at Birmingham was wrecked by a mob who disapproved of his sympathy with the French revolution, and three years after he went to the United States, where he died in 1804.