100 



SPECIFICITY OF RICKETTSIA PROWAZEKI 



Record of Guinea-pig 4@, inoculated with the viscera of 

 louse 2 of Box XXXVII _ 



May 24 102.2 



Temperatures following the inoculation on May 24th : 



F. 



June 11 101.0 



" 12 101.2 



13 101.4 



14 101.0 



15 101.2 



16 No record 



17 No record 



18 102.1 



19 102.4 



20 No record 



21 101.4 



22 No record 



23 102.1 



24 No record 



25 102.2 



26 No record 



27 102.0 



On June 28th this guinea-pig was inoculated intraperitone- 

 ally with 5 c.c. of blood from patient 814 (eighth day of typhus). 

 The subsequent temperatures were as follows: 



June 28 102.1 



29 No record 



30 102.2 



Ju y 1 102.4 



2 No record 



3 104.8 



4 102.4 



5 102.0 



6 No record 



7 . . 102.2 



July 8 102.5 



" 9 No record 



10 102.4 



11 102.6 



12 102.4 



13 104.8 



14 104.6 



a 15 No record 



16 104.4 



17 . . 104.1 



July 17th; killed. The autopsy was negative except for an 

 enlarged spleen covered with a thin transparent fibrin-like layer. 

 The tissues were lost, and no histological data were obtained. 



Result: Guinea-pig 42, inoculated with the viscera of 

 louse 2 of Box xxxvn, during an observation period of thirty- 

 four days, did not develop typhus. Fifteen days after inocula- 

 tion with human typhus blood it developed, coincidently with 

 others receiving the same blood, the reaction of typhus. 



Conclusion: Louse 2 of Box xxxvn did not contain the 

 virus of typhus. 



