DESCRIPTIONS OF PATHOGENIC BACTERIA. 2 19 



germ injected subcutaneously, followed with intravenous injections. 

 After two months of treatment with filtered cultures the more 

 potent doses of cultures sterilized by ether may be used ; it is not 

 until five to six months after the beginning of the treatment that the 

 first injection of a living culture may be safely hazarded. During 

 this process of immunization many of the animals die and all are 

 profoundly affected. 



The serum of animals immunized in this way is endowed with pro- 

 tective and curative properties and can be used with success in 

 animal experiments. A single instance may serve to illustrate the 

 results obtained by this procedure. A horse under treatment for the 

 space of nine months received subcutaneously during this period 

 29c.c. of filtered cultures and 350 c.c. of cultures sterilized with ether, 

 and intravenously 2640 c.c. of sterilized cultures, 345C.C. of living broth 

 cultures and 19 c.c. of an agar culture. The serum (0.5 c.c.) from this 

 animal, when injected into a guinea-pig 24 hours before inoculation 

 with several times the fatal dose, conferred immunity ; 2c.c. proved 

 potent enough to save the lives of guinea-pigs when injected 48 

 hours after inoculation. E. O. J.] 



