PROTOCOLS OF EXPERIMENTS 69 



On June 22d this guinea-pig 13 was inoculated intraperi- 

 toneally with 5 c.c. of blood from patient 799 (eighteenth day of 

 typhus). Its temperatures subsequently were as follows: 



F. F. 



June 23 104.0 July 10 102.0 



24 No record 



" 25 102.9 



a 26 No record 



a 27 103.0 



28 103.1 



" 29 No record 



30 103.3 



July 1 104.0 



2 No record 



3 104.0 



4 102.8 



u 5 103.0 



6 No record 



" 7 . . 102.1 



11 102.2 



12 102.1 



13 101.8 



14 101.9 



15 No record 



16 102.1 



17 101.7 



18 102.0 



19 101.8 



20 102.0 



21 No record 



22 102.5 



23 102.6 



24 . . 103.0 



8 102.1 25 101.7 



" 9 No record 



Result: Guinea-pig 13, inoculated with rickettsia-infected 

 louse W 211 developed a reaction consistent with typhus fifteen 

 or sixteen days later. -Following an injection of 5 c.c. of typhus 

 blood of known infectivity it failed to develop temperatures 

 consistent with typhus during an observation period of thirty- 

 three days, thereby proving immunity to typhus. 



Conclusion: Rickettsia-infected louse W211 contained the 

 virus of typhus. 



Record of Guinea-pig 7, inoculated with the viscera of 

 rickettsia-free louse W 212 



The temperature, following the inoculation on May 15th, 

 rose on one day, May 23, to 104F. At no other time did the 

 temperature pass out of the normal range until June 21st when 

 it was 103. 5F. On June 22d, after this observation period of 

 thirty-eight days, it received intraperitoneally 5 c.c. of blood 

 from patient 799 (eighth day of typhus) with the following 

 result: 



