Your favor of Nov. 4. 09. did not get to my hands till a twelvemonth after it’s date. be pleased to accept my thanks for the publication you were pleased to send me. that for Dr Barton I forwarded to him. his researches into the Indian languages of our continent being continued, I hope it will be in his power to make to you communications useful to the object you are pursuing. this will lessen to me the regret that my retirement into an interior part of the country, as well as my age and little intercourse with the world, will scarcely afford me opportunities of contributing to your information. it is extremely to be desired that your researches should recieve every aid & encouragement. I have long considered the filiation of languages as the best proof we can ever obtain of the filiation of nations. with my best wishes for the success of your undertaking accept the assurances of my high consideration & respect

Th: Jefferson