368 THE POPULAR SCIENCE MONTHLY. 



his humility and disinterestedness. In writing of this period he 

 says, " While the vaccine discovery was progressive, the joy I felt 

 was at the prospect before me of being the instrument destined to 

 take away from the world one of its greatest calamities." 



What he really accomplished during those twenty-five years 

 of preparation and waiting is, succinctly, as follows : 



1. He perceived that some profound modification of the effects 

 of the virus of smallpox occurred when it was introduced through 

 a puncture in the skin, instead of finding its way to the system 

 through the natural channels of the lungs and the stomach. 



2. That cow-pox was really smallpox in cows,* but that the 

 disease in passing through the tissues of that animal underwent a 

 still greater modification, by which its period was lessened, and 

 that it became non-contagious, unless a person brought in contact 

 with it had some abrasion of the skin. 



3. That persons who had accidentally acquired it from the cow 

 did not give it to others while passing through it, and were hence- 

 forth secure from attacks of smallpox. 



It was his putting of " this and that together " that made the 

 great step forward : could this modified virus be inoculated suc- 

 cessfully into the human system as smallpox had been ; and, if 

 so, would it protect against smallpox ? James Phipps had fur- 

 nished the triumphant answer, and his other twenty-two cases 

 had confirmed its truth. He did not find a second opportunity for 

 putting his hypothesis to the test till 1798 ; he then repeated his 

 inoculations with the utmost care, and prepared his book for print- 

 ing. Before giving his work to the press, he devoted the most 

 solemn and conscientious care to it, reading it sentence by sen- 

 tence to a few of his most intimate friends and asking for their 

 unsparing criticism. Its title was, An Inquiry into the Causes and 

 Effects of the Variolze Vaccinse (Cow-pox). These friends saw in 

 it a great victory of the sagacity of man over one of the most fatal 

 of diseases, and they urged him forward in his purpose of opening 

 for the benefit of all " the stream of life and health he had been 

 permitted to discover " ; in their enthusiasm they said " he seemed 

 to hold in his hand one of the gates of death, with power to close 

 it." In addition to the great fact that constituted the vital kernel 

 of his discovery, he had incidentally learned much besides. He 

 was convinced that there were two similar-appearing diseases 

 affecting cows that could be imparted to man, one of which he 

 named " spurious," and which afforded no protection against 

 smallpox. He also learned that there were rare cases where per- 



* An opinion confirmed by an account of experiments published in La Semaine Medicate, 

 December 31, 1890, made by Elternod, of Geneva; Haccius, the Director of the Vaccine Insti- 

 tute of Lancy ; and of Dr. Fischer, Director of the Vaccine Institute at Carlsruhe in Germany 



