PROTOCOLS OF EXPERIMENTS 



97 



Result: Guinea-pig 40 did not develop typhus during an 

 observation period of thirty-six days following inoculation 

 with the viscera of louse 1 of Box xxxvi. Fifteen days follow- 

 ing the injection of human blood from patient 814 it developed 

 a moderately elevated temperature lasting for six days, fol- 

 lowed by normal temperatures. 



Conclusion: 

 of typhus. 



Louse 1 of Box xxxvi did not contain the virus 



Experiments with Box XXXVII lice 



Between feedings the box was kept in an incubator at a 

 temperature varying from 20 to 30 C., usually 29 C. The 

 box contained 30 W lice (30 nymphs). 



