Unless this culture and this traffic in smallpox throughout the United Kingdom be realised, the potent cause of the immediate and extravagant success of Vaccination will be left out of reckoning. When we are harassed, anxious and impatient under some course of conduct, our ears are open to any promise of relief; and it was to a generation so afflicted and so receptive that Jenner in 1798 made his revelation of the virtue of cowpox. No more need, said he, to inoculate with smallpox. Substitute cowpox; and whilst it will protect as effectually, it will inflict no injury and diffuse no infection. The revelation was received with acclamation, and within eighteen months of its delivery (without due experience, and without any warrant that could pass muster in the severe realm of science) the leading physicians and surgeons of London subscribed and published the following manifesto in the newspapers of 1800-- We, the undersigned physicians and surgeons, think it our duty to declare our opinion, that those persons who have had the Cowpox are perfectly secure from the infection of the Smallpox, provided this infection has not been previously communicated. I do not wish to anticipate the wondrous tale of Jenner--my present purpose is to show how Inoculation was set aside; and it suffices to state that cowpox rapidly made an end of inoculation with smallpox. Indeed, I question whether a revolution in practice was ever effected with similar facility. Within eight years of the delivery of Jenner’s revelation, the writer in the _Edinburgh Review_ of 1806, already cited, was able to testify-- The bitterest enemies of Vaccination will not deny, that more than nine-tenths of the medical world are decidedly and zealously in favour of it, and that all their demonstrations of its dangers and terrors have been insufficient to convert a single one of their brethren from so damnable and dangerous a heresy. Testimonies, it may be said, should be weighed, and not numbered; and in this respect the vaccinators, we are afraid, will have a splendid and indisputable triumph. We give the anti-vaccinists all the advantage in our power when we assign to them a few members of the profession in London; for in the country at large, we believe, they have not one respectable practitioner on their side in five hundred. In this great city and school of medicine [Edinburgh] we are assured, they are without a single public adherent.