82 SPECIFICITY OF RICKETTSIA PROWAZEKI 



F. F. "* 



July 10 102.0 July 18 102.0 



11 102.0 19 101.7 



12 102.1 20 102.1 



13 102.6 21 No record 



14 102.0 22 . ...: 102.5 



15 No record " 23 102.0 



16 102.2 24 102.0 



17 101.9 25 102.2 



Result: Guinea-pig 29 did not react to the injection of 

 viscera of louse W 265, during an observation period of thirty- 

 seven days. Following an injection of human typhus blood of 

 proved infectivity it failed to react satisfactorily during a 

 further observation period of thirty-three days. 



Conclusion: The negative result of the louse inoculation 

 carries more weight than the result of the immunity test; be- 

 cause, the failure of a guinea-pig to react to the inoculation of 

 proved infective blood is common. Yet, we do not feel war- 

 ranted in drawing a positive conclusion from this experiment. 

 Nevertheless, we do conclude that the presence of the virus of 

 typhus was not proved in louse W 265. 



Record of Guinea-pig SO, inoculated with rickettsia-free 

 louse W 266 



This guinea-pig's temperature did not exceed normal limits 

 between May 16th, the date of inoculation, and June 22d. On 

 June 22d it was inoculated intraperitoneally with 5 c.c. of blood 

 from patient 799 (eighth day of typhus) and the subsequent 

 temperatures were as follows: 



F. F. 



June 22 No record July 5 102.8 



23 104.0 



24 No record 



25 103.9 



26 No record 



27 104.0 



28 103.1 



29 No record 



30 103.2 



July 1 102.6 



2 No record 



3 104.3 



4 . . 102.8 



6 No record 



7 103.4 



8 102.6 



9 No record 



10 101.8 



11 103.0 



12 102.1 



13 102.8 



14 101.9 



15 No record 



16 104.4 



17 . . 104.1 



