First edition. Printed by Richard and Arthur Taylor for the London Unitarian Society. London. 1815. Octavo. xvi, 493pp. 3pp publisher's adverts. Contemporary half calf, marbled boards. Rubbed with wear to extremities. Some spotting/foxing, mostly to endpapers. Occasional light marginal pencil. Bookplate of "G. P. Burns, M.B.E., Methodist Local Preacher and Associate Member of the Crusaders' Union" to fep, and his signature dated 1936 to ffep. Joseph Priestley (1733-1804) British Enlightenment polymath. Scientist, theologian, philosopher he was the first to identify oxygen and other core gases. He invented soda water. In 1794 he emigrated to Pennsylvania where was befriended by Thomas Jefferson as 'one of the few lives precious to mankind'. His achievements have only recently begun to be acknowledged. His metaphysical works influenced Jeremy Bentham, John Stuart Mill, and Herbert Spencer. Thomas Belsham (1750-1829) Nonconformist author. Successor to Priestley at Hackney. The Priestley v. Horsley, Unitarian v. Trinitarian controversy documented for the first time. Contains the four letters which were left with Belsham by Priestley, "to be published or suppressed at his discretion… the two early letters were written at an early period of the French Revolution…"