GELSTON ON STUDY OF EPIDEMIC AMONG GUINEA PIGS. 87 



well at room tciupiMjituie, but not bc4o\v 18 degiees. It is destroyed by 

 five minutes exposure at (iO dej^rees moist heat and by an exposure of 

 one minute to 7(1 de<»rees. It resists exposure for one hour to 50 degrees 

 in moist heat. This organism is a facultative anaerobe, growing well in 

 glucose and plain media and in an atmosphere of hydrogen. (Jas pro- 

 duction has been observed in all media, but more abundantly in glucose 

 I^reparations. Mercuric chlorid, 1:1000, destroys the organism in one 

 minute, and carbolic acid of five per cent strength has tlic same effect. 

 The bacillus is pathogenic to all of tlie ordinary laboratory animals, — 

 guinea pigs, rats, mice and rabbits; other animals have not jet been 

 tested. Intraperitoneal injections of one cubic centimeter of a 

 twenty-four houis bouillon culture kill in from twelve to eight- 

 een hours. Subcutaneous injections of one cubic centimeter of a like 

 culture kill in from one to three days. The lymphatic glands near the 

 point of inoculation are markedly enlarged and a thick, bloody, gelatinous 

 exudate is found subcutaneously about the place of inoculation. One 

 drop of blood from the heart of an animal dead from infection with this 

 germ, injected into the peritoneal cavity of a guinea pig, kills in from 

 eighteen to twenty-four hours. A small piece of the spleen of an infected 

 animal inserted subcutaneously in a healthy pig was followed by death 

 in from one to three days. Whatever the mode of inoculation, the bacillus 

 is always found in the blood of the heart after death. The period of 

 infection when animals are fed with cultures varies from one to three 

 weeks. 



