DEAR SIR,--A continuation of poor health makes me an irregular correspondent. I am, therefore, your debtor for the two letters of January 20th and February 21st. It was after you left Europe that Dugald Stuart, concerning whom you inquire, and Lord Dare, second son of the Marquis of Lansdown, came to Paris. They brought me a letter from Lord Wycombe, whom you knew. I became immediately intimate with Stuart, calling mutually on each other and almost daily, during their stay at Paris, which was of some months. Lord Dare was a young man of imagination, with occasional flashes indicating deep penetration, but of much caprice, and little judgment. He has been long dead, and the family title is now, I believe, in the third son, who has shown in Parliament talents of a superior order. Stuart is a great man, and among the most honest living. I have heard nothing of his dying at top, as you suppose. Mr. Tickner, however, can give you the best information on that subject, as he must have heard particularly of him when in Edinburgh, although I believe he did not see him. I have understood he was then in London superintending the publication of a new work. I consider him and Tracy as the ablest metaphysicians living; by which I mean investigators of the thinking faculty of man. Stuart seems to have given its natural history from facts and observations; Tracy its modes of action and deduction, which he calls Logic, and Ideology; and Cabanis, in his Physique et Morale de l'Homme, has investigated anatomically, and most ingeniously, the particular organs in the human structure which may most probably exercise that faculty. And they ask why may not the mode of action called thought, have been given to a material organ of peculiar structure, as that of magnetism is to the needle, or of elasticity to the spring by a particular manipulation of the steel. They observe that on ignition of the needle or spring, their magnetism and elasticity cease. So on dissolution of the material organ by death, its action of thought may cease also, and that nobody supposes that the magnetism or elasticity retire to hold a substantive and distinct existence. These were qualities only of particular conformations of matter; change the conformation, and its qualities change also. Mr. Locke, you know, and other materialists, have charged with blasphemy the spiritualists who have denied the Creator the power of endowing certain forms of matter with the faculty of thought. These, however, are speculations and subtleties in which, for my own part, I have little indulged myself. When I meet with a proposition beyond finite comprehension, I abandon it as I do a weight which human strength cannot lift, and I think ignorance, in these cases, is truly the softest pillow on which I can lay my head. Were it necessary, however, to form an opinion, I confess I should, with Mr. Locke, prefer swallowing one incomprehensibility rather than two. It requires one effort only