PROTOCOLS OF EXPERIMENTS 71 



Result: Guinea-pig 14, inoculated with louse W 213, ap- 

 parently free of rickettsia, developed a course typical of typhus 

 after an incubation period of eight days. The infection was 

 proved to be typhus by histological examination. 



Conclusion: Louse W 213, a preparation of which contained 

 no rickettsia, contained the virus of typhus. 



Record of Guinea-pig 8, inoculated with the viscera of 

 rickettsia-free louse W 214 



F. F. 



May 15 102.1 May 27 104.2 



16 101.4 28 104.0 



17 104.0 29 103.8 



18 104.4 30 103.6 



19 104.4 31 104.0 



20 104.5 June 1 103.8 



21 105.0 2 103.6 



22 104.6 3 102.6 



23 104.4 4 103.9 



24 104.3 5 103.2 



25 104.0 " 6 103.0 



26 102.9 7 102.4 



From June 7th to June 21st the temperatures were normal. 

 On June 22d this guinea-pig was inoculated intraperitoneally 

 with 5 c.c. of blood from patient 799 (eighth day of typhus); 

 the following temperatures resulted: 



F. F. 



June 23 103.4 July 6 No record 



24 No record 



25 No record 



26 No record 



27 102.6 



28 No record 



29 102.4 



CO 102.1 



July 1 103.3 



2 No record 



3 103.8 



4 . . 104.2 



7 102.4 



8 102.0 



9 No record 



10 103.0 



11 102.4 



12 102.6 



13 102.7 



14 103.2 



15 No record 



16 102.2 



17 . . 102.0 



5 104.2 



Discussion: The rise of temperature in guinea-pig 8, after the 

 inoculation with louse W 214, was too early for typhus, but not 

 inconsistent with the reaction in a guinea-pig harboring a mild 

 or latent infection. The duration of the temperature covered 



