258 BACILLUS OF SYMPTOMATIC ANTHRAX 



dangerous because of the unavoidable risk of injecting a portion of 

 the juice into the connective tissue, in which case a violent local 

 infection generally leading to death results. Even when all the juice 

 is injected into the veins, there still remains the danger of a fatal 

 local infection at some point where an accidental hemorrhagic con- 

 tusion in the subcutaneous or muscular tissue has occurred. This 

 fact has given rise to the belief that emphysematous anthrax is often 

 an intestinal infection, as already stated. Thomas' vaccination 

 method, known as the "vaccination par le fil virulent," was the first to 

 be practised more extensively. The procedure consists in saturating 

 a bundle of silk threads with an attenuated culture of black-leg 

 bacilli which have passed through the body of the frog. The silk 

 threads are inserted in the tail by a special vaccination needle 

 devised by Thomas. This method has been used in France on 

 at least a million and a half head of cattle, with good results. 

 Later, the French workers prepared two vaccines, one considerably 

 attenuated, which was used for the first inoculation and one less 

 attenuated for the second. Kitt's experiments on the resistance of 

 the black-leg bacillus and its spores led him to work out what is now 

 the most commonly used method in the protective inoculation of 

 cattle against natural black-leg infection. Dried and ground-up 

 muscles from cattle dead from emphysematous anthrax are exposed 

 for five or six hours to steam of a temperature of 97 C., after which 

 the powder is again completely dried. It was found that this powder 

 in doses of 0.2 to 0.6 gram still killed sheep, but in smaller doses 

 immunized and protected them. Kitt's method, used with excellent 

 results in Europe, was somewhat modified in the United States by 

 Noergaard, of the Bureau of Animal Industry, who exposed the 

 ground-up infected muscles from cattle for six hours to 93 to 95 C. 

 The latter vaccine has been successfully used on several million head 

 of cattle. It may be remembered, however, that occasionally an 

 animal treated with the vaccine dies from the inoculation, but this 

 number is so small as to become a negligible quantity when com- 

 pared with the great protective value of the vaccination. 



Directions for the Use of Black-leg Vaccine. The following is an 

 abstract of the directions given by tbe Bureau of Animal Industry for 

 the use of its prepared vaccine: The black-leg vaccine, as prepared 

 by the Bureau, consists of a brownish powder, which is put up in 

 packets containing either ten or twenty-five doses each. To prepare 

 this powder in such a way that it may be injected hypodermically, 

 it is necessary to use certain implements. The outfit consists of a 

 porcelain mortar, with pestle, a small glass funnel, a measuring glass, 

 and a syringe. For filtering the vaccine, absorbent cotton is most 

 suitable. The syringe used has a capacity of 5 cubic centimeters, 

 and the piston is graduated from one to five, eaeh division being 

 subdivided with half and quarter notches. The screw-regulator may 

 be placed at any mark on the piston, thus insuring that the animal 



