The first individual in England on whom the operation of inoculation for Small Pox was performed, was the daughter of the celebrated Lady Mary Wortley Montague. She had witnessed, when in Turkey, the mildness of this disease as produced by inoculation, and her son had already passed through the process with safety. “The engraftment of her son having succeeded; after Lady M. W. M. returned to London in 1722, she sent for Mr. Maitland, the surgeon, who had attended the boy at Constantinople; and desired him to engraft her daughter with Small Pox. He solicited a delay, on account of the weather, and entreated that two physicians should be consulted. These requests were refused, yet he obeyed her Ladyship’s injunctions; but when the fever commenced, an old family apothecary and three physicians were permitted to witness the process. As the success was complete, Dr. Keith, one of the above physicians, was tempted to request Mr. Maitland to engraft his child also, which likewise succeeded; and these cases were rumoured through the town.”[5]—An experiment was afterwards tried, at the request of the Princess of Wales, upon “six condemned felons” with success, and her own children passed through the operation with safety. After this, inoculation was partially employed for some years, and was again discontinued—but, about the middle of the last century, great exertions were made to bring it into general use, and with a considerable degree of success. We shall presently endeavour to ascertain what influence it exerted over the prevalence and fatality of Small Pox. But, in the first place, I think it will be useful to enquire into some of the arguments which were adduced in support of the practice; and, it may be, to allude to a few which were opposed to it. ----- Footnote 5: Moore’s History of Small Pox, p. 228-9. ----- The principal arguments, on which the employment of inoculation for Small Pox was supported, appear to have been the following:— 1. The infectious nature of the disease, which was so virulent as to permit few individuals to pass through life without being at one time or other affected by it. 2. Its fatality—destroying at least one in five or six of those attacked by it. 3. The generally received opinion that no individual could be affected by it oftener than once. And 4. That, when communicated by inoculation, it was rendered comparatively mild and devoid of danger, while it afforded equal security against any future attack of the disease. The two former of these positions need not engage our attention in this place—the highly infectious nature of Small Pox has always been admitted; and I have already brought forward sufficient proof of the danger to human life which it occasions.