To Thomas Jefferson from Thomas Patterson, 30 March 1808
on or before 30 Mch 1808
I am sorry to inform the President that I have not any of the Extract of Peruvian Bark—as that article contains a considerable proportion of resin it will require either spiritous liquor or a tolerably high degree of heat to effect its solution—If none of it can be procured in George town I could make some of it by tomorrow evening—twelve grains forms a dose about equal to 60 grains of the substance of Bark—
very Respecy
Thos Patterson
MHi: Coolidge Collection.