GENUS BACILLUS 339 



juice is spread in layers on plates and dried quickly at a tem- 

 perature 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 virulence for two years or longer. 



When vaccine is to be prepared, the dried material is 

 pulverized 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 10 cc. 

 water, filtered and the filtrate injected in doses of one cubic 

 centimeter.* 



The U. S. Bureau of Animal Industry finds that this 

 vaccination is exceedingly helpful in preventing disease. Vac- 

 cine to the extent of hundreds of thousands of doses is sent 

 out by the Bureau annually for this purpose. 



BACILLUS OEDEMATIS LIBORIUS. 



Synonyms. Bacillus oedematis maligni Koch ; Vibrion 

 septique Pasteur. 



Place in nature. This organism is the cause of a malig- 

 nant oedema in man and in certain animals. It is closely 

 related to the bacillus of blackleg. It was isolated in pure 

 culture by Liborius. 1 It had previously been found by Pas- 

 teur and others, in putrid material. It was studied by Koch 2 



* Norgaard. Blackleg in the United States and the distribution 

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

 B. A. I., U. S. Dept. of Agric., 1898. 



1 Liborius. Zeit. f. Hyg., Vol. I (1886) p. 115. 



2 Koch. Mitt. a. d. Kais. Gesundheitsamt., Bd. I (1881) p. 52. 



