B. ANTHRACIS: EXPERIMENTS. 367 



one carbolic acid tube into another, and see if it is 

 possible by this means to influence in any way the 

 production of spores by the organism with which you 

 are working. What is the effect, if any ? 



Prepare two bouillon cultures, each from one drop of 

 blood of an animal dead of anthrax. Allow one of them 

 to grow for from fourteen to eighteen hours in the incu- 

 bator ; allow the other to grow at the same temperature 

 for three or four days. Remove the first after the time 

 mentioned and subject it to a temperature of 80° C. for 

 thirty minutes. At the end of this time prepare four 

 plates from it. Make each plate with one drop from 

 the heated bouillon culture. At the end of three or four 

 days treat the second tube in identically the same way. 

 How do the number of colonies which developed from 

 the two different cultures compare ? Was there any 

 difference in the time required for their development on 

 the plates ? 



From a potato culture of anthrax bacilli \vhich has 

 been in the incubator for three or four days, scrape 

 away the growth and carefully break it up in 10 c.c. of 

 sterilized normal salt solution. The more carefully it 

 is broken up the more accurate will be the experiment. 

 Place this in a bath of boiling water and at the end of 

 one, three, five, seven, and ten minutes make a plate 

 upon agar-agar with one loopful of the contents of this 

 tube. Are the results on the plates alike ? 



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. 



