I breakfasted this morning with Sir Humphry Davy, of whom we have heard so much in America. He is now about thirty-three, but with all the freshness and bloom of five-and-twenty, and one of the handsomest men I have seen in England. He has a great deal of vivacity,-talks rapidly, though with great precision, and is so much interested in conversation, that his excitement amounts to nervous impatience, and keeps him in constant motion.