In the Report we detect one good service, namely, the explosion of Jenner’s fiction about Spurious Cowpox. When Vaccination was first brought forward, cases were adduced of Smallpox after Cowpox. Jenner at once asserted that the Cowpox in such instances must have been spurious, for Smallpox after genuine Cowpox was impossible; and Spurious Cowpox was thenceforward freely used to baffle inquirers and to account for failures. Spurious Cowpox served the ends of the Vaccinators magnificently, but by and by it began to have awkward consequences. Genuine Cowpox was said to be harmless--it was the Spurious that was ineffective or worked mischief; and the Inoculators plied the terror of Spurious Pox against Vaccination. It therefore became necessary to clear Spurious Cowpox out of the way, and Jenner, before the College of Physicians, pressed upon the point, “owned up,” as Americans say, and authorised the following explanation-- Some deviations from the usual course have occasionally occurred in Vaccination, which the Author of the practice has called Spurious Cowpox, _by which the public have been misled, as if there were a true and a false Cowpox_; but it appears that nothing more was meant than to express irregularity or difference from that common form and progress of the vaccine pustule from which its efficacy is inferred. Mark! Here was a third definition of Spurious Cowpox by Jenner. _First_, in the _Inquiry_ of 1798, he described Spurious Cowpox as eruptions on the cow underived from horsegrease, producing no erysipelas when inoculated on the human subject, and without effect against Smallpox. True Cowpox was generated from horsegrease, and from horsegrease only. _Second_, in the _Origin of the Vaccine Inoculation_ of 1801 all reference to horsegrease was dropped for commercial reasons, whilst the existence of Spurious Cowpox was reasserted “as some varieties of spontaneous eruptions upon the cow.” _Third_, before the Physicians in 1807, he removed the spurious disease from the cow altogether, saying, nothing more was meant by Spurious Cowpox than variations in the form and progress of vaccine pustules on the arms of the vaccinated! In short, to vary the phrase of Betsy Prig, “There never was no Spurious Cowpox.” Slippery, very slippery, was the immortal Jenner. With the report of the Royal College of Physicians were delivered reports from the London College of Surgeons, and from the Edinburgh and Dublin Colleges of Physicians and of Surgeons. The report from the London College of Surgeons was considered most unsatisfactory, and could its tenor have been foreseen, the Jennerians might never have asked for it. 1100 circulars were dispatched on 15th December, 1806, to all the members of the College whose addresses were known in the United Kingdom, submitting the following questions-- 1st. How many persons have you vaccinated? 2nd. Have any of your patients had Smallpox after Vaccination?