Boswell mentions Douglas in connection with a supper at Lord Eglinton's together with John Ross Mackye on November 25, 1762, however it is not entirely clear if the General was present at this meeting, or if Boswell had met him at some other time during his first week in London. Described by Boswell as "a plain a civil man". A relative of the 3rd Duke of Queensberry according to Pottle (LJ251162).