A HISTORY OF SCIENCE 



vancing to maturation, so that I cannot determine 

 whether they had any connection with the preceding 

 symptoms. 



"Thus the disease makes its progress from the horse 

 (as I conceive) to the nipple of the cow, and from the 

 cow to the human subject. 



" Morbid matter of various kinds, when absorbed 

 into the system, may produce effects in some degree 

 similar; but what renders the cow-pox virus so ex- 

 tremely singular is that the person that has been 

 thus affected is forever after secure from the infection 

 of small-pox, neither exposure to the variolous effluvia 

 nor the insertion of the matter into the skin producing 

 this distemper." 3 



In 1796 Jenner made his first inoculation with cow- 

 pox matter, and two months later the same subject 

 was inoculated with small-pox matter. But, as Jenner 

 had predicted, no attack of small-pox followed. Al- 

 though fully convinced by this experiment that the 

 case was conclusively proven, he continued his inves- 

 tigations, waiting two years before publishing his dis- 

 covery. Then, fortified by indisputable proofs, he 

 gave it to the world. The immediate effects of his 

 announcement have probably never been equalled in 

 the history of scientific discovery, unless, perhaps, in 

 the single instance of the discovery of anaesthesia. In 

 Geneva and Holland clergymen advocated the prac- 

 tice of vaccination from their pulpits; in some of the 

 Latin countries religious processions were formed for 

 receiving vaccination; Jenner's birthday was cele- 

 brated as a feast in Germany; and the first child vac- 



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