1Thomas Jefferson to Samuel K. Jennings, 23 September 1815 (Jefferson Papers)
I thank you for the pamphlet you have been so kind as to send me, and I have read it with great pleasure. but when you request an opinion on it, it is more than I am able to give or to form. I am not sufficiently intimate with the structure of our frame, nor yet with the medical agents which may change it’s condition from bad to good, or the converse, to decide between systems on which the...