105 



When the colonies develop their form should be care- 

 fully studied as it is very characteristic, and, if possible, 

 impression preparations should b6 made from the surface 

 colonies and stained with methylene blue. 



As the colony is a pure culture of the anthrax bacillus, 

 transplantations to tubes in turn yield pure cultures. Make 

 a stich culture in gelatin and a streak culture on inclined 

 agar. This latter is made by simply drawing the end of 

 the platinum wire along the middle on the surface of the 

 agar. The agar tube is placed in the incubator at 37 to 

 39 G. for one or two days, then removed and examined. 



Another agar tube is liquefied and -J to 1 drop of cal- 

 cium hydrate is added, thoroughly mixed, and the tube is 

 then set aside in an inclined position till the agar solidifies. 

 Then make a streak culture on this Ca (OH) 2 -agar, and 

 set it aside to develop in the incubator. 



With the pure cultures of the anthrax bacillus thus 

 obtained the student can inoculate a number of white 

 mice, white rats and rabbits, and in these, after death, the 

 organism can in turn be detected and isolated. In this 

 way each one has an opportunity to demonstrate all four 

 rules of Koch with reference to anthrax, thus proving that 

 the anthrax bacillus is the cause of the disease. 



MICROSCOPICAL EXAMINATION. 



Hanging-drop. Take a clean f -inch cover-glass and 

 pass it once through the flame. Transfer a small drop of 

 sterile bouillon to the cover-glass and then add to it, with a 

 sterilized wire, a minute amount of the heart-blood. 

 Apply the concave slide, ringed with vaseline, and 

 examine the hanging-drop, thus prepared, with the No. 7 

 objective. Study the characteristics of the anthrax 

 bacillus as it exists in the blood, and compare its size with 

 that of the blood-cell. Then label the slide and set aside 

 in the incubator for 24 hours. Examine the slide 

 on the following day and observe the formation of 

 threads, of sporogenic granules and possibly of spores. 



