Repaired at nine to Mr. A. Smith's: present, all the company of Friday except Bogle and Macaulay. Mr. Playfair, a mathematician, and Mr. Muir from Gottingen were there. Talked of Junius. Adam Smith suspected "single speech" Hamilton to be the author. He was told by Gibbon that when Hamilton one day paid a visit at the Duke of Richmond's in Sussex, he told him that there was a devilish keen letter from Junius in the Public Advertiser of that day, and mentioned some of the passages. The duke was anxious to see it, but when the paper came there was an apology in it for its not appearing. It was a letter to the Duke of Richmond, and the last that appeared. As long as they were ascribed to Lord Lansdowne, Burke, Germaine, &c., they went on, but as soon as they were said to be Hamilton's they were stopped.