Page:An Inquiry into the Causes and Effects of the Variolæ Vaccinæ - 1798.djvu/55

 We have seen that the virus from the horse, when it proves infectious to the human subject is not to be relied upon as rendering the system secure from variolous infection, but that the matter produced by it upon the nipple of the cow is perfectly so. Whether its passing from the horse through the human constitution, as in the present instance, will produce a similar effect, remains to be decided. This would now have been effected, but the boy was rendered unfit for inoculation from having felt the effects of a contagious fever in a work-house, soon after this experiment was made.

WILLIAM SUMMERS, a child of five years and a half old was inoculated the same day with Baker, with matter taken from the nipples of one of the infected cows, at the farm alluded to in. He became indisposed on the 6th day, vomited once, and felt the usual slight symptoms till the 8th day, when he appeared perfectly well. The progress of the pustule, formed by the infection of the virus was