Your letter of the 9th has been duly recieved. I am able to give but little information on the subject of Madder. I know it has been cultivated, ever since I can remember, in this state for houshold use; and before the revolution it was cultivated on a large scale by some. Colo Harrison, a member of the 1st Congress, was one of these and told me he did not believe it could be cultivated to better advantage in any country than in this. I do not know why he discontinued it, but probably for the want of sale: there not being enough made to employ merchants for that article only, and our merchants of that day being all confined to the tobacco line. it is still cultivated over the whole of this state, I believe, that is to say by some one in every neighborhood, a little being sufficient for a whole neighborhood: for altho’ with us, nearly every family in the country make their own clothing, scarcely any is made for sale. this answers your first quaere, and for all the rest I must refer you to McMahon’s book of gardening, published in Philadelphia where he resides, & carries on the business of a seedsman. he gives the best account of it’s culture, & can probably furnish the seed of the best species. here it is preferred to use the root undried. in that case it is washed, & after 12 hours beaten into a paste. the same quantity of root will go twice as far in that way as dried. we dry it in the open air when necessary. it takes three years from the planting to be fit for use. this is the sum of the information I recieve on the subject. Accept my salutations.

Th: Jefferson