From what has already been said, it will be evident, that Vaccination has produced these very beneficial consequences in two ways. 1. By superseding an efficient cause of the spread of infection, namely, the practice of inoculation for Small Pox. And 2. by essentially interfering with the effect of the infectious virus. The increased number of deaths, which took place during the period when inoculation for Small Pox was generally employed, is sufficient to prove the influence of Vaccination to have been considerable in the former way; but a formal application having been made to me to inoculate a child for Small Pox, since I commenced these remarks, I think it right to call the attention of the public more decidedly to the pernicious tendencies of the practice. The attention of the medical profession, and of the public generally, was soon excited by the increasing number of deaths after the introduction of inoculation, and exertions were made to check it, particularly by the establishment of the Small Pox Hospital. This, no doubt, had some effect, by separating a part at least of those to whom Small Pox was artificially communicated from the rest of the community; but the event proved that this was by no means an adequate defence against the factitious causes of infection, which were daily called into action. The Small Pox Hospital still exists, and it is a very remarkable fact, that, for several years after the discovery of Vaccination, out-patients continued to be inoculated at that institution. This, no doubt, contributed to prevent the proportion of deaths from Small Pox in London from diminishing so rapidly as would otherwise have been the case, and as has been the case, since this “unaccountable infatuation,” as Sir Gilbert Blane very justly calls it, has been discontinued. But, as the same eminent physician properly remarks (p. 6), “it was in the rural population that the effect of inoculation in diffusing Small Pox was chiefly felt. In this situation, there is much less intercourse of persons with each other than in towns, so that not only many individuals escaped, from their not being exposed to infection during their whole lives, but whole districts were known to have been exempt from it for a long series of years before it was universally diffused by inoculation.” We may, therefore conclude, that while the number of deaths from Small Pox, within the bills of mortality, was increased in the proportion exhibited in the tables by means of inoculation, in the country the increased mortality from this cause was in a much greater ratio. This supposition is in a great degree confirmed by the effects occasioned by a renewal of the practice of inoculation, in Norfolk, in the year 1819, as recorded by Mr. Cross, in his History of the Epidemic Small Pox, which at that time prevailed in the city of Norwich and the county of Norfolk. Mr. Cross mentions