78 BACTERIOLOGY. 



THE BACILLUS OF ANTHRAX. 



Anthrax is primarily a disease of cattle and 

 sheep, although horses, hogs, and goats are suscep- 

 tible. The infection may be transmitted directly to 

 man from infected animals or from their hides or 

 wool. The disease exists for the most part in Europe 

 and the East, but in the United States it is rarely met 

 with. 



The anthrax bacillus was the first micro-organism 

 definitely proved to be the cause of a specific disease. 

 It is a large, straight rod with square-cut ends. It is 

 not motile. In cultures they are prone to form long 

 chains or threads. Spores are formed, which are 

 situated in .the center of the bacterial cells. They are 

 very resistant to harmful influences. While the bacil- 

 lus itself may be destroyed by an exposure of ten 

 minutes to heat at 54 C, the spores require an ex- 

 posure of three hours' dry heat at 140 C. and live 

 steam for five to ten minutes. They will resist drying 

 for years. A 5 per cent, solution of carbolic acid re- 

 quires forty days to kill them, and bichloride of mer- 

 cury i : 1000 forty minutes. Direct sunlight destroys 

 them in six to twelve hours. 



P ent a ry 0f ^hc ^ ac i^ tls finds its way into the bodies of cattle 



principally through the alimentary tract. In man the 

 portal of entrance is more often through the skin and 

 respiratory tract. Those handling live stock, butchers, 

 and tanners are most liable to contract the disease. 

 The first symptom of anthrax is a pustule or boil, 



