Joseph Priestley (1773-1804) was a scientist, a Dissenter and a supporter of the French Revolution. He was involved in the Dissenters’ attempts to secure repeal of the Test and Corporation Acts in 1787-1790, and wrote a series of Letters to William Pitt and Letters to Burke to try to persuade them to lend their support; but Pitt’s administration accused Priestley and his fellow-Dissenters of wanting to overthrow the government, and Edmund Burke associated Priestley with revolutionary excesses in his Reflections on the Revolution in France. In July 1791, Priestley and other Dissenters arranged a dinner in Birmingham to celebrate the storming of the Bastille, a provocation that led to three days of riots in which Priestley’s house and laboratory were destroyed, together with twenty-six other Dissenters’ homes and several churches. He moved with his family to Hackney in Middlesex, but they were considered to be in danger, and in 1793 the entire family left for America, where they lived in Philadelphia and in Northumberland, Pennsylvania. Priestley died in Northumberland in 1804, aged seventy.