return it, if the original was safe, and to keep it, if not. I have heard no more of it. My intention was, and is, if it is returned to me, to deposit it with your committee for safe keeping or publication. While on the subject of Louisiana, I have thought I had better commit to you also an historical memoir of my own respecting the important question of its limits. When we first made the purchase we knew little of its extent, having never before been interested to inquire into it. Possessing, then, in my library, everything respecting America which I had been able to collect by unremitting researches, during my residence in Europe, particularly and generally through my life, I availed myself of the leisure of my succeeding autumnal recess from Washington, to bring together everything which my collection furnished on the subject of its boundary. The result was the memoir I now send you, copies of which were furnished to our ministers at Paris and Madrid, for their information as to the extent of territory claimed under our purchase. The New Orleans MS. afterwards discovered, furnished some valuable supplementary proofs of title. I defer writing to the Secretary at War respecting the observations of longitude and latitude by Capt. Lewis, until I learn from you whether they are recovered, and whether they are so complete as to be susceptible of satisfactory calculation. I salute you with great respect and esteem. TO MR. WIRT. MONTICELLO, January 5, 1818.