Petersburg, September 18, 1807.
You do me unspeakable honour in finding time to acknowledge having received the Pamphlet which I took the liberty to send you. Accept, I entreat you, my thanks. I should trespass against the public were I to write more,
Cum tot sustineas et tanta negotia solus.
I am, with perfect respect, Sir, Your most obedient Servant,
DLC: Papers of Thomas Jefferson.