EXPERIMENTS. 241 



Determine the exact time necessary to sterilize ob- 

 jects, such as silk or cotton threads, on which anthrax 

 spores have been dried, by the steam method and by the 

 hot-air method. 



Prepare from the blood of an animal just dead of an- 

 thrax a bouillon culture. After this has been in the 

 incubator for from three to four hours, subject it to a 

 temperature of 55° C. for ten minutes. At the end of 

 this time make plates from it, and also inoculate a rabbit 

 subcutaneously with it. What are the results? Are 

 the colonies on the plates in every way characteristic? 



Inoculate six Erlenmeyer flasks of sterile bouillon, 

 each containing about 35 c c: of the medium, from either 

 the blood of an animal just dead of anthrax or from a 

 fresh virulent culture in which no spores are formed. 



Place these flasks in the incubator at a temperature 

 of 42.5° C. At the end of five, ten, fifteen, twenty, 

 twenty-five, etc., days remove a flask. Label each flask 

 as it is taken from the incubator with the exact number 

 of days for which it had been at the temperature of 

 42.5° C. Study each flask carefully, both in its cultural 

 peculiarities and its pathogenic properties, when em- 

 ployed on animals. 



Are these cultures identical in all respects with those 

 that have been kept at 37° C. ? 



If they differ, in what respect is the difference most 

 conspicuous ? 



Should any of the animals survive the inoculations 

 made from the different cultures in the foregoing exper- 

 iment, note carefully which one it is, and after ten to 



