He was called to the Scottish Bar in 1806. Alongside his uncle,
Sir William Douglas of Castle Douglas, he was a partner in the Galloway Banking Co. (Douglas, Napier, & Co), established in
Castle Douglas in 1806 and which ceased trading in 1821, because of a bad debt. He was president of the
Speculative Society between 1806 and 1809. An active Christian, he represented his parish as Ruling Elder at the Annual Meeting of the
General Assembly of the Church of Scotland in 1811. Having previously tried for
Kirkcudbright, but been rejected, he was subsequently elected as member of Parliament for
Plympton Erle from December 1812 to June 1816, during which time he is not known to have spoken, and has just seven recorded votes. In 1812, he was elected a Fellow of the
Royal Society of Edinburgh. His proposers were
Thomas Allan,
Allan Maconochie, Lord Meadowbank, and
John Playfair. ==Personal life==