John Bonnycastle 

John Bonnycastle (1751-1821) was a friend of the popular painter-writer Henry Fuseli (1741-1825) and of William Godwin and Joseph Johnson. He was a mathematician and a former General Baptist turned Unitarian and sceptic whose successor at the Royal Military College at Woolwich was Olinthus Gregory (1774-1841), a Particular Baptist layman and biographer of Robert Hall. Bonnycastle was baptized at the General Baptist meeting in St. Paul’s Alley, Barbican, in the spring of 1773. Through his friendships with Joseph Johnson, Joseph Priestley, William Godwin, and Henry Fuseli, however, he moved into Unitarianism and eventually scepticism by 1800, remaining so to his death, despite many earnest discussions about faith with Gregory. See Barbican Church Minute Book (later Worship Street), 1695-1851, Angus Library, Regent’s Park College, Oxford; also "Infidels Think Sometimes," The Friend. A Religious and Literary Journal 8 (1835), 404.