BUBONIC PLAGUE 107 



and that whatever immunity they enjoy is due to the 

 observance of sanitary precautions, the importance of 

 which has become apparent as we have acquired a 

 more exact knowledge of the etiology of the disease. 



During the past few years a number of prominent 

 bacteriologists have been engaged in researches re- 

 lating to the prevention and cure of bubonic plague 

 by means of an antitoxic serum, obtained by the same 

 method and in accordance with the same funda- 

 mental scientific principle as in the case of the anti- 

 toxic serum which is now so successfully employed in 

 the treatment of diphtheria. The experiments thus far 

 made have apparently been attended with a consider- 

 able degree of success. Professor Calmette reports 

 that the serum of Yersin prepared at the Pasteur 

 Institute in Paris proved to be curative in a con- 

 siderable proportion of the cases treated during the 

 recent outbreak at Oporto, and that protective inocu- 

 lation conferred a temporary immunity, which, how- 

 ever, did not last longer than twenty days. The 

 mortality in cases not treated by Yersin's serum was 

 70 %, in those treated with it 13 %. 



The inoculations made by Haffkine in Bombay 

 appear to have been quite successful. In his first 

 experiment 8142 persons were inoculated. Of these, 

 1 8 subsequently contracted the disease and 2 died. 

 Among 4926 persons inoculated a single time at 



