70 SPECIFICITY OF RICKETTSIA PROWAZEKI 



June 22 No record July 5 106.0 



23 . . 103.8 6 . . No record 



24 No record 



25 No record 



26 No record 



27 102.4 



28 No record 



29 102.4 



30 102.4 



July 1 103.0 



" 2 No record 



3 104.5 



4 105.8 



7 105.4 



8 105.0 



9 No record 



10 103.2 



11 102.7 



12 102.8 



13 103.1 



14 102.2 



15 No record 



16 102.1 



17 . . 102.2 



July 17th; killed. The autopsy showed a slightly enlarged 

 spleen. There were no lesions in other tissues. 



Result: Guinea-pig 7, inoculated with louse W 212, during an 

 observation period of thirty-eight days failed to develop tem- 

 peratures suggestive of typhus. Following an inoculation of 

 typhus blood, after a further observation period of ten or eleven 

 days, it developed temperatures and a course typical of typhus. 



Conclusion: Rickettsia-free louse W 212 did not contain the 

 virus of typhus. 



Record of Guinea-pig 14, inoculated with the viscera of 

 rickettsia-free louse W 213 



The temperatures following the inoculation on May 15th 

 were as follows: 



May 15 102.3 May 22 104.2 



16 102.0 23 104.0 



17 101.9 24 104.6 



18 102.4 25 104.6 



19 102.6 26 104.3 



20 102.2 27 104.2 



21 103.4 28 104.0 



May 28th; killed. The autopsy showed an enlarged spleen 

 covered with a thin transparent fibrin-like layer. No lesions 

 were found in any other tissues. 



On histological examination the lesions characteristic of 

 typhus were found in the brain. 



