He was baptized at Dunbar on 26 November 1740, the son of a surgeon. From 1759 to 1763, he was a Surgeon's Mate in the Navy. Returning home to medical practice, he joined the fledgling Methodist society and became a local preacher. His house was home for the itinerants and he helped John Wesley organize Methodism in Scotland. As a leading Town Councillor, in 1768 he organized the defence of Dunbar against French attacks. In 1771 he received an MD from Aberdeen University and in 1780 was elected a Fellow of the Royal College of Physicians of Edinburgh. In 1790 he moved to Leeds, married into a wealthy family and was the first layman to preach at a Methodist Conference. In 1794 he became Physician to the London Dispensary, lived in Finsbury Square and was an influential member at Wesley's Chapel. He worked, unsuccessfully, to keep Methodism as a religious society within the Established Church. In 1789 he was the first layman to preach at a Methodist Conference. He died in London on 21 April 1827 and was buried at Wesley's Chapel.