The two letters which you have done me the honor to write to me, dated the 6th & 7th ultimo, have been laid by me1 before the Historical Committee of the Philosophical Society, together with the valuable Manuscripts which accompanied them. They have directed me to return you their warm thanks for these fresh instances of your enlightened & unwearied Zeal in the Cause of Science & literature, & for the promotion of the best interests of your Country. I shall not particularly designate the MSS. which we have received, it is Sufficient to Say that all those mentioned in your letters as forwarded by you have come to hand, & will be disposed of according to your Wishes.

Mr Biddle, who is a Member of our Historical Committee has promised to assist us in obtaining the remainder of Messrs Lewis & Clark’s Manuscripts. He is at present, I presume, actively employed with Mr Vaughan in effecting this desirable object. The Committee will consider themselves as the Depositaries of these papers for all useful purposes, & Subject to the orders of the Government. They & the Society in their respective Departments will in the mean while exert themselves to make them Subservient to the great objects of their institution—

The Committee are highly pleased with your kind offer to Present them with your remaining Indian Vocabularies, which will be to them a highly Valuable gift—They are now in possession of a considerable & interesting Collection of materials relating to the manners, Customs & languages of the Indians, enough, indeed, to make a handsome Octavo Volume. These Vocabularies will add much to this collection, & will be received with gratitude.

You know perfectly well, Sir, that the Indian languages of our Country North of the Carolinas & East of the Mississipi, may nearly all be considered as Dialects of two Mother tongues, the Iroquois & the Algonquin. On the subject of the languages of the latter stock, which are the most numerous, we are possessed of considerable information, but we are very deficient as to the former. We have, however, lately discovered Sources from whence we hope to be able fully to Supply this deficiency.

The “Secret history of the line” which you had the goodness to send to us is a very interesting Book. There is no doubt that it was written by the same person who wrote the other MSS. which I formerly Sent to you & which you have returned. On Comparing them together, I find that they both relate to the same time & to the same operation, with this difference, that the one is fuller than the other & has no affected concealment of Names. By a Careful collation of them, I have no doubt that every thing in the “Secret history” will be explained, & the meaning of every fictitious name will be obtained.

I feel much flattered by the attention you have paid to my little “Essay on Phonology”—There can be no doubt that gradual improvements in Orthography are desirable, but at the same time I am Sure that the impracticability of a Sudden total change has struck you as it has me. I assure you, Sir, that it is always a Source of pride & pleasure to me when I find my opinion Coincide with yours, which is always looked up to by Men of far greater pretensions than I can ever expect to be entitled to.2