46 iMMimiZATIOIf. 



In order to ascertain the presence of the immune 

 body, the immunized and the virulent sera were mixed 

 and injected hypodermically to healthy horses. The 

 results are given in the following table. 



Results 



10.0 C.C. Symptoms appear- 

 ed in 13 days 

 Symptoms appear- 

 ed in 13 days 

 No symptoms over 

 3 months 



Symptoms appear- 

 ed in 22 days 



From the above experiment, it is concluded that 

 the immune serum contained no preventive property 

 against the artificial infection. Besides, a new supposi- 

 tion was entertained that the virus might be contained 

 in the blood of an immunized horse, for we had an 

 evidence of the presence of the germ in the blood of an 

 animal for a long time after an apparent recovery from 

 the disease was noticed. The following experiment was 

 performed in order to test the validity of our supposition. 



Experimental Horse Immune serum Results 



No. 13 20.0 c.c. Symptoms appeared in 



15 days 



From the above experiment, it becames clear that 

 immune serum does contain the virus, and that it can. 



* The horse No. 10 must have had natural immunity; for it did not become 

 ill even when it was inoculated with the virulent serum alone after a certain 

 pause. 



