DEAR SIR,--An absence of six weeks has occasioned your letters of the 5th and 11th inst., to lie thus long unacknowledged. After I had sent off the two other Westover MSS. I received a third of the same journal. On perusing it I am not sensible by memory, of anything not contained in the former, except eight pages of a preliminary account of the abridgment of our limits by successive charters to other colonies. I suppose this to be a copy of the largest of the other two, entered fair in a folio volume, with other documents relating to the government of Virginia. It is bound in vellum, and, by the arms pasted in it, seems to have been intended for the shelves of the author's library. As this journal is complete it might enable us to supply the hiatuses of the other copies. I now send you the remains of my Indian vocabularies, some of which are perfect. I send with them the fragments of my digest of them, which were gathered up on the banks of the river where they had been strewed by the plunderers of the trunk in which they were. Those will merely show the arrangement I had given the vocabularies, according to their affinities and degrees of resemblance or dissimilitude. If you can recover Capt. Lewis' collection, they will make an important addition, for there was no part of his instructions which he executed more fully or carefully, never meeting with a single Indian of a new tribe, without making his vocabulary the first object. What Professor Adelung mentions of the Empress Catharine's having procured many vocabularies of our Indians, is correct. She applied to M. de La Fayette, who, through the aid of General Washington, obtained several; but I never learnt of what particular tribes. The great works of Pallas being rare, I will mention that there are two editions of it, the one in two volumes, the other in four volumes 4to, in the library I ceded to Congress, which maybe consulted. But the Professor's account of the supposed Mexican MS. is quite erroneous, nor can I conceive through whom he can have received his information. It has probably been founded on an imperfect knowledge of the following fact: Soon after the acquisition of Louisiana, Governor Claiborne found, in a private family there, a MS. journal kept, (I forget by whom,) but by a confidential officer of the French government, proving exactly by what connivance between the agents of the compagnie d'occident, and the Spaniards, these last smuggled settlements into Louisiana, as far as Assinais, Adais, &c., for the purpose of covering the contraband trade of the company. Claiborne, being afraid to trust the original by mail, without keeping a copy, sent it on after being copied. It arrived safe, and was deposited by me in the office of State. He then sent me the copy, on the destruction of the office at Washington by the British; apprehending the original might be involved in that destruction, I sent the copy to Colonel Monroe, then Secretary of State, with a request to