To Benjamin Rush
June 24. 1803. Washington.
Th: Jefferson to Dr. Rush
I am thankful to you for your attentions to Capt Lewis while at Philadelphia and the useful counsels he recieved from you. he will set out in about 4. or 5. days, and expects to leave Kaskaskias about the 1st. of September. he will have two travelling months which will probably carry him 7. or 800. miles up the river for his winter quarters, from whence he will communicate to us, in the course of the winter his observations so far. he tells me you wish to see the inclosed pamphlet on longevity by Sr. John Sinclair, which you can return me at your leisure. Accept affectionate salutations.
PrC (DLC). Enclosure: Sir John Sinclair, An Essay on Longevity (London, 1802); see Vol. 37:537.