REFERENCES 285 



and dried quickly at a temperature of about 35" C. This 

 temperature does not in the least affect the bacteria, and the 

 dry virus obtained in this way retains a high degree of viru- 

 lence for two years or longer. 



When vaccine is to be prepared, the dried material is pul- 

 verized and mixed in a mortar with two parts water until it 

 forms a semifluid homogeneous mass. This is spread in a thin 

 layer on a suitable glass dish and placed in an oven, the 

 temperature of which may be regulated with exactness. The 

 reason for mixing the dried muscle with water is to insure a 

 quicker and more uniform attenuation. The temperature of 

 the oven is previously brought up to 95° to 99° C, and the 

 virus is allowed to remain in it for six hours. When removed 

 it appears as a brownish scale, which is easily detached from 

 the dish. This scale is pulverized and put up in packages con- 

 taining 10 doses each. Before it is used, it is mixed with 

 ID c. c. water, filtered and the filtrate injected in doses of one 

 cubic centimeter. 



REFERENCES. 



1. Fisher. Blackleg in Kansas, and protective inoculation. 

 Kan. State Agric. Exper. Station, 1901. 



2. Lewis. Symptomatic anthrax. Bulletin No. ^7. Oklahoma 

 State Agric. Exper. Station, 1897. 



3. Mayo. Blackleg. Bulletin No. 69. Kan. State Agric. 

 Exper. Station, 1897, p. 108. 



4. NoRGAARD. Blackleg in the United States and the distribution 

 of vaccine by the Bureau of Animal Industry. Annual Report of the 

 Bureau of Animal Industry U. S. Dept. Agric. 1898. 



5. NoRGAARD. Blackleg. Its nature, cause and prevention. 

 Circular No. 23. U. S. Bureau of Animal Industry, 1898. 



6. Paquin. Blackleg. Bulletin No. 12. Mo. Agric. Exper. 

 Station, i8go. 



7. Peters. Blackleg. Its nature, cause and prevention. Bulle- 

 tin No. 65. Neb. State Agric. Exper. Station, 1900. 



8. Sai<mon. Black quarter. Annual Report Bureau of Animal 

 Industry, U. S. Dept. of Agric. 1893-4. 



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