The death of his father two years later put Dalrymple in possession of a sufficient fortune to enable him to indulge his literary tastes; but he did not neglect his professional studies. As an oral pleader he was not successful. A defect in articulation prevented him from speaking fluently, and he was naturally an impartial critic rather than a zealous advocate. Notwithstanding this defect, he practised at the bar with much reputation for eighteen years. A great part of the business of litigation in Scotland at this time was conducted by written pleadings, and he became known as a learned and accurate lawyer. On 6th March, 1766, Dalrymple was raised to the bench, on the death of George Carre of Nisbet, with the title of Lord Hailes, and on the resignation of George Brown of Coalston he was appointed a Lord of Justiciary on 3rd May, 1776. In the latter capacity he was distinguished for dignity, humanity, and impartiality--qualities at that times by no means characteristic of the criminal bench. The solemnity of his manner in administering oaths and pronouncing sentence specially struck his contemporaries. As a judge in the civil Court he was noted for his critical acumen and unswerving integrity. In knowledge of the history of law he was surpassed by none of his brethren, though among them were Elchies, Kaimes, and Monboddo. At Edinburgh Lord Hailes lived some time in the Old Mint Close, foot of Todrick’s Wynd; he next had a house in Society, Brown’s Square; and latterly removed to New Street. His general residence was New Hailes, Musselburgh, where he died of apoplexy, the result of sedentary habits, on 29th November, 1792. Dr. “Jupiter” Carlyle, of Inveresk, who knew him well, summed up his character in a funeral sermon, in which he drew a glowing character of one of the most worthy of all the learned men of his time.