54 



Dr. E. T. Hewlett. 



[Mar. 28, 



Immunisation against the Vibrio cholera?. 

 The endotoxin solution was prepared on June 29, 1909. On August 11, 

 1909, six guinea-pigs (300 to 400 grm. weight) were each inoculated 

 subcutaneously with - 25 mgrm. On September, 15, 1909, these guinea-pigs 

 were each inoculated intra-peritoneally with one loop of cholera culture, 

 equivalent to about two minimum lethal doses. Three control animals were 

 inoculated at the same time with the culture, two receiving ' one loop each, 

 the third 0*5 loop. 



All the six vaccinated animals survived, but of the controls the two 

 receiving 1 loop of culture were dead on September 16, and the one receiving 

 - 5 loop was very ill but recovered. 



The cholera endotoxin, therefore, protected the animals against living 

 cholera culture. 



Immunisation against the Bacillus pestis. 



The plague endotoxin was prepared in the usual manner, and was used 

 fresh (24 hours old). Subsequently the animals were inoculated with 

 virulent plague culture. The results are shown in the following tables 

 (Tables YII and VIII) :— 



Series I. — The guinea-pigs were injected subcutaneously with 1 mgrm. 

 of plague endotoxin on August 11, 1909, and, together with controls, were 

 inoculated intra-peritoneally with plague culture on September 15. 



Table VII. 



Reference No. of 



Amount of 



Amount of 



Eesult. 



guinea-pig. 



endotoxin. 



culture. 











1 



1-0 ' 



•}>„ loop 





2 

 3 



1-0 

 1 -o 







4 



1 -o 







5 



1 -o 







6 



1 -o 







Control 



Control 





+ Dead, Sept. 19. 

 Lived. 



The animals which survived were alive and well on October 2, 1909, i.e. 

 17 days after inoculation with the plague culture. 



Series II. — The plague endotoxin was that prepared on August 10, 1909. 

 The guinea-pigs were injected subcutaneously with plague endotoxin on 

 November 18, and, together with the controls, were inoculated intra- 

 peritoneally with virulent plague culture on December 9, i.e. three weeks 

 later. 



