You seem not perfectly satisfied that the origin of vaccine is clearly made out. For my part, I should think that Loy’s experiments were sufficient to establish it, to say nothing of Sacco’s and others on the Continent. However, I have now fresh evidence, partly foreign and partly domestic. The latter comes from Mr. Melon, a surgeon of repute at Lichfield. He has sent me some of his equine virus, which I have been using from arm-to-arm for two months past, without observing the smallest deviation in the progress and appearance of the pustules from those produced by the vaccine.[149] And in a subsequent note of 1st August, he repeated-- DEAR MOORE,--I have been constantly equinating for some months, and perceive not the smallest difference between the pustules thus produced and the vaccine. Both are alike, because they come from the same source.[150] To Moore again he wrote from Cheltenham, 27th October, 1813-- I am sorry you have not succeeded in infecting a cow. I have told you before _that the matter which flows from the fissures in the horse’s heels will do nothing_. [Note the observation placed in italics.] The virus is contained in vesicles on the edges and the surrounding skin. Did I ever inform you of the curious result of vaccinating carters? From their youth these men have the care of horses used for ploughing our corn lands; and great numbers have come to me from the hills to be vaccinated, but the half have proved insusceptible. On inquiry, many of them have recollected having sores on their hands and fingers from dressing horses affected with sore heels, and being so ill as to be disabled from work; and on several of their hands, I have found the cicatrix as perfect and characteristically marked as if it had arisen from my own vaccination.[151] Then we have a memorandum of Jenner’s, dated 1st April, 1817, wherein he thus traces the course of the virus-- Rise and progress of the equine matter from the farm of Allen at Wansell. From a horse to Allen; from Allen to two or three of his milch cows; from the cows to James Cole, a young man who milked at the farm; from James Cole to John Powell by inoculation from a vesicle on the hand of Cole; and to Anne Powell, an infant; from Powell to Samuel Rudder; from Rudder to Sophia Orpin, and to Henry Martin; from H. Martin to Elizabeth Martin. All this went on with perfect regularity for eight months, when the virus became intermixed with other matter, so that no journal was kept afterwards. Proof was obtained of the patients being duly protected[152]-- Which was to say, that they were subsequently inoculated with Smallpox without effect. Among Jenner’s papers, there were other entries to the same purpose, thus-- _17th May, 1817._--Took matter from Jane King (equine direct) for the National Vaccine Establishment. The pustules beautifully correct.[153]