Your’s of the 19th. is at hand. soon after my arrival at Monticello in Aug. I recieved from Dr. Waterhouse of Boston some vaccine matter of his own taking and some from Dr. Jenner of England just then come to hand. both of them took well, and exhibited the same identical appearances in the persons into whom they were inserted. I inoculated about 70 or 80 of my own family, my two sons in law as many, in Aug. & Sep. all had kernels under the arms, and a single pustule, to wit that made by the insertion. one or two of the whole number had very sore arms and 4. or 5 pustules on the arm. about 1 in 4. or 5. or 6. had slight feverish dispositions for an evening or two. none of them changed their regimen, & few intermitted their ordinary occupations. the inoculation of the mother in no instance gave it to the child which sucked her. being cautioned by Dr. Waterhouse to be particularly attentive to the state of the matter with which I inoculated, I was so & believe that I preserved the disease in it’s genuine form. I found that taking the premature & the tardy cases of maturation, there was one day which both comprehended, to wit, the 8th. (say 8. times 24. hours) from the time of inoculation. at that point of time I do not know that I ever saw the matter in any patient either unformed, or shewing a commencement of maturation. I brought some matter to Dr. Gantt here who now inoculates from it, & means to try the variolous inoculation on some of his patients. I had no opportunity of doing that. I sent some matter to Doctr. Waterhouse, & I shall have his opinion in due time whether it had been continued genuine. from the trials I made, the Cowpox can hardly be called a disease. it produces no more inconvenience than a burn or blister of a quarter of an inch diameter.

I propose some Saturday morning to ride & explore the road you described to me. if I knew on what Saturday I should find you at home, I would breakfast with you, and take your further directions to find it. Accept my best wishes for your health & happiness.