When his friend William Cobbett was in Newgate Prison, Bosville went in his coach and four to visit him, and afterwards gave him a cheque for £1,000 as a token of sympathy with him in his persecutions.
He used always to dress in the style of a courtier of King George II, and wore a single-breasted coat, powdered hair and queue.
He was raised to the rank of lieutenant on 11 January 1769, and served with his regiment through part of the American War of Independence, where "no doubt he imbibed his republican sentiments".
[6] He was an intimate friend of John Horne Tooke, to whose house at Wimbledon Bosville used to drive down in a coach and four to dinner every Sunday during the spring and autumn for many years, and is mentioned in his Diversions of Purley.
A slate was kept in the hall, in which any of his intimate friends might write his name as a guest for the day, Besides Horne Tooke, Sir Francis Burdett, 5th Baronet, Lords Hutchinson and Oxford, Parson Este, and others, often availed themselves of this privilege.
[6] He died unmarried at his house in Welbeck Street on 10 December 1813 in his sixty-ninth year, and was buried on the 21st of the same month in the chancel of St Giles in the Fields.