vaccinated the other not, and none of them having had small-pox, and then having the resulting effects carefully described and compared by independent experts. Such “control” experiments would now be required in any case of such importance as this; but it was never done in the early days of vaccination, and it appears never to have been done to this day. The alleged “test” was, it is true, applied in a great number of cases by the early observers, especially by Dr. Woodville, physician to a small-pox hospital; but Dr. Creighton shows reason for believing that the lymph he used was contaminated with small-pox, and that the supposed vaccinations were really inoculations. This lymph was widely spread all over the country, and was supplied to Jenner himself, and we thus have explained the effect of the “vaccination” in preventing the subsequent “inoculation” from producing much effect, since both were really mild forms of small-pox inoculation. This matter is fully explained by Dr. Creighton in his evidence before the Royal Commission, printed in the Second Report. Professor E. M. Crookshank, who has made a special study of cow-pox and other animal diseases and their relation to human small-pox, gives important confirmatory evidence, to be found in the Fourth Report. This brief statement of the early history of vaccination has been introduced here in order to give what seems to be a probable explanation of the remarkable fact that a large portion of the medical profession accepted, as proved, that vaccination protected against a subsequent inoculation of small-pox, when in reality there was no such proof, as the subsequent history of small-pox epidemics has shown. The medical and other members of the Royal Commission could not realize the possibility of such a failure to get at the truth. Again and again they asked the witnesses above referred to to explain how it was possible that so many educated specialists could be thus deceived. They overlooked the fact that a century ago was, as regards the majority of the medical profession, a pre-scientific age; and nothing proves this more clearly than the absence of any systematic “control” experiments, and the extreme haste with which some of the heads of the profession expressed their belief in the lifelong protection against small-pox afforded by vaccination, only four years after the discovery had been first announced. This testimony caused Parliament to vote Jenner £10,000 in 1802.