392 SPECIFIC MICRO-ORGANISMS 



cutaneously with emulsions of the spinal cords which have been 

 removed from rabbits dying of rabies after inoculation with the 

 fixed virus, and which have been dried by hanging in bottles 

 over caustic soda for some time. The first injection is prepared 

 from cords hung for 14 and 13 days, the second from cords hung 

 12 and II days, and so on until the three-day cord is reached on 

 the seventh or eighth day of the treatment. The series from 

 five-day down to three-day cords is then repeated several times, 

 the whole treatment lasting about 2 1 days. The course of treat- 

 ment is varied somewhat according to the urgency of the case and 

 the severity of the wounds inflicted. It is most effectively carried 

 out at special Pasteur institutes devoted to this work, but the 

 material for injection may be shipped for some distance when 

 necessary. 



The Virus of Hog Cholera. — Dorset, Bolton and McBryde, 

 continuing the investigations of de Schweinitz, demonstrated in 

 1905 the presence of a filterable agent in the blood of hogs suffering 

 from hog cholera, capable of causing the disease upon injection 

 into healthy animals. It passes through the Chamberland "B" 

 and "F" filters. It leaves the body in the urine and probably 

 also in other excretions, and seems to enter the new victim with 

 the food and drink. The virus resists drying for three days, 

 remains alive in water for many weeks and in glycerine for eight 

 days. It is destroyed at 60° to 70° C. in an hour. 



King, Baeslack and Hoffman^ have found a short, rather thick, 

 actively motile spirochete, Spirochata suis, in the blood in forty 

 Cases of hog cholera, together with abundant granules which may, 

 perhaps, represent a stage of this organism. The spirochete has 

 not been found in healthy hogs. It seems probable that this 

 organism may prove to be the causative agent of the disease, but 

 further evidence is necessary to demonstrate this relationship. 



Hog cholera is an extremely contagious disease of hogs, fre- 

 quently fatal, characterized by fever and by ulcerations in the 

 intestine. Immunity follows recovery and is induced artificially 

 1 Journ. Infect. Dis., iqis, Vol. XII, pp. so-47: dp. 206-2;?";. 



