570 PATHOGENIC SPIRILLA. 



and cause symptoms similar to those which result from the intro- 

 duction into guinea-pigs of the living bacteria ; that from these fil- 

 tered cultures a solid substance can be obtained having the same 

 toxic properties, and that from susceptible animals which have been 

 treated with this toxic substance a serum can be obtained which is 

 active not only against the cholera poison, but against the cholera 

 vibrio. These results support those previously reached by other 

 bacteriologists and lead to the hope that a specific treatment of the 

 disease may be successfully employed. The results obtained by 

 Haffkine in India are favorable to the view that his method of prophy- 

 laxis, by the subcutaneous injection of virulent cholera cultures, has 

 a real value. 



