Roehampton. Only Moore and myself; Washington Irving and Maclane, the American Minister, come to-morrow. Moore spoke in the highest terms of Luttrell, of his wit and information, and of his writings, to which he does not think the world does justice, particularly the 'Advice to Julia,' but he says Luttrell is too fearful of giving offence. Moore was very agreeable, told a story of Sir ---- St. George in Ireland. He was to attend a meeting at which a great many Catholics were to be present (I forget where), got drunk and lost his hat, when he went into the room where they were assembled and said, 'Damnation to you all; I came to emancipate you, and you've stole my hat.' In the evening Moore sang, but the pianoforte was horrid, and he was not in good voice; still his singing 'va dritto al cuore,' for it produces an exceeding sadness, and brings to mind a thousand melancholy recollections, and generates many melancholy anticipations. He told me as we came along that with him it required no thought to write, but that there was no end to it; so many fancies on every subject crowded on his brain; that he often read what he had written as if it had been the composition of another, and was amused; that it was the greatest pleasure to him to compose those light and trifling pieces, humorous and satirical, which had been so often successful. He holds Voltaire to have been the most extraordinary genius that ever lived, on account of his universality and fertility; talked of Scott and his wonderful labour and power of composition, as well as the extent to which he has carried the art of book-making; besides writing this history of Scotland for Dr. Lardner's 'Encyclopaedia,' he is working at the prefaces for the republication of the Waverley Novels, the 'Tales of a Grandfather,' and has still found time to review Tytler, which he has done out of the scraps and chips of his other works. A little while ago he had to correct some of the proofs of the history of Scotland, and, being dissatisfied with what was done, he nearly wrote it over again, and sent it up to the editor. Some time after finding another copy of the proofs, he forgot that he had corrected them before, and he rewrote these also and sent them up, and the editor is at this moment engaged in selecting from the two corrected copies the best parts of each.