298 BACTERIOLOGY. 



confirmed by Fewster and Sutton in London 

 in 1768. The landowner Jesty in 1774 first 

 intentionally inoculated himself and his family 

 with cow-pox for the purpose of gaining pro- 

 tection against small-pox. A Holstein teacher, 

 one Pless, and above all the English surgeon 

 Jenner developed the method systematically. 

 They inoculated persons first with the cow-pox, 

 then with genuine small-pox, and observed 

 that in these cases the inoculation with small- 

 pox material no longer produced any effect. In 

 order to do away with the danger, for danger 

 was never wholly absent since some persons 

 died in consequence of the artificial small-pox 

 inoculation, and especially to put a stop to the 

 spread and maintenance of the small-pox 

 contagion by these artificial - inoculations, 

 Jenner, after thirty years of experiment, intro- 

 duced the practice of systematic inoculation 

 with the supposedly independent virus of cow- 

 pox. This is the method of vaccination as 

 opposed to that of variolation. The fourteenth 

 of May, 1796, is regarded as the day of the first 

 official inoculation with vaccine, and hence the 

 century jubilee of this great hygienic achieve- 

 ment has been lately celebrated. The protec- 

 tion conferred by vaccination was not so ef- 

 fective and did not last so long as that afforded 

 by artificially induced small-pox or by a natural 



