It does not appear the genuine Vaccine Pock can be propagated like the Smallpox by effluvia from persons labouring under it. Hence if the Vaccine Inoculation should be universally instituted in place of the Smallpox, it is reasonable to conclude, that this most loathsome and fatal malady will be extinguished; and, like the Sweating-Sickness, the Plague, certain forms of leprosy, etc., be known in this country only by name. It does not appear that the Vaccine Poison, like that of the Smallpox, can be conveyed so as to produce the disease indirectly from diseased persons, by adhering to clothes, furniture, bedding, letters, etc. Hence no danger of its propagation in these channels is to be apprehended from the universal practice of the inoculation of the Cowpock. It has been found that a person, whose constitution has distinctly undergone the Vaccine Disease, is in future insusceptible of the same disorder. [_Thus re-vaccination was treated as impossible._] Experience shows, that there is no reason to apprehend the smallest chance of deformities of the skin from the Vaccine Inoculation. The extensive practice of the Vaccine Inoculation in the present year, and the accounts of the disease in the casual way do not show that any other disease will be excited subsequently. A further considerable public benefit expected is, that a stock of efficacious Vaccine Matter, _free from contamination by the Smallpox_, will by this Institution be preserved for the use of the public. These statements are interesting as showing how early the rollicking tunes were set to which at this day we are expected to dance. The last paragraph is noteworthy as a confession under Pearson’s hand that vaccine poison had got confused with variolous, and that the mistake would henceforth be avoided. Jenner maliciously and persistently used this mishap, for which Woodville was responsible, to discredit Pearson and magnify his own pretensions; but, as Pearson observed, neither Jenner nor any one else knew that it was possible to have cowpox and smallpox simultaneously. The mistake was made, however; and, as is the function of mistakes, knowledge was enlarged. Pearson’s behaviour in the matter was as creditable to him as Jenner’s was otherwise. The Vaccine Pock Institution was organised with a staff of physicians, surgeons, and apothecaries of the highest London respectability; and as it was desired to have the benefit of Jenner’s name (his active co-operation, as a resident in Gloucestershire, being out of the question) Pearson wrote to him-- LONDON, _10th December, 1799_.