He served as Solicitor of Excise in Scotland, and was known as a scholar and supporter of learned societies.
He was one of the original promoters of the Astronomical Institution, and one of the founders of the Edinburgh Subscription Library in 1794.
[2] In March 1788 it was Bonar who discovered Deacon Brodie robbing the excise office where he worked, at Chessel's Court on the Canongate (still extant).
[4] Paterson's Court lay next to Broughton market at the west end of what is now Barony Street.
He published an English edition of Holbein's Dance of Death, 1788, and wrote the memoir of his brother Archibald Bonar in the second volume of his sermons.