PROTOCOLS OF EXPERIMENTS 57 



Record of Guinea-pig 19, inoculated with rickettsia-infected 



louse W 239 



The temperatures following the inoculation on May 15th 

 were as follows: 



F. F. 



May 15 101.5 May 21 105.0 



16 101.9 " 22 105.0 



" 17 102.7 u 23 104.6 



18 102.7 " 24 105.5 



19 106.3 " 25 104.4 



20 105.2 



May 25th; killed. The spleen was slightly enlarged and 

 covered with a thin transparent fibrin-like layer. In the liver 

 were two hard white nodules, evidently of healed pseudo- 

 tuberculosis. The other tissues were negative. Cultures of 

 blood from the heart proved sterile three days later. 



The histological examination showed the characteristic brain 

 lesions of typhus (see p. 194). 



Three other guinea-pigs, Nos. 50, 51, and 52, were inoculated 

 intraperitoneally each with 2 c.c. of blood from the heart of 

 guinea-pig 19. 



Guinea-pig 50 developed temperature on June 7th which 

 lasted five days, following which it was normal and on June 

 28th it was tested for immunity by the intraperitoneal injec- 

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

 During a further observation period of twenty days its tem- 

 perature remained normal. 



Guinea-pig 51 developed temperature on May 6th which 

 lasted for seventeen days. From June 25th to June 28th tem- 

 perature was normal. On June 28th it was inoculated intra- 

 peritoneally with 5 c.c. of blood from patient 814 (eighth day of 

 typhus). During a further observation period of twenty days 

 its temperature remained normal. 



Guinea-pig 52 developed no characteristic temperature re- 

 action but between June 2d and 10th had occasional elevations 

 to 104 F. On May 30th it was tested by an intraperitoneal in- 

 oculation with 5 c.c. of blood from patient 828 (tenth day of 



