Peeventive Ikocdlation and Disinfection. 49 



Experimental horse No. 449 received intravenous 

 inoculation of 50.0 c.c. of the serum of Experimental 

 goats No. 2 and 3. No change was noticed for 76 days. 

 40.0 c.c. of the serum of Experimental goat No. 3 was 

 then inoculated intravenously. Nothing happened for 

 55 days. It then received an intravenous inoculation of 

 20.0 c.c. of the virulent serum. It contracted the disease 

 with a period of incubation of 9 days. 



The results of the above experiments alone will not 

 be strong enough to decide whether the virus disappears 

 or simply loses its virulence by passing the goat. Should 

 the latter supposition be correct, we might be able to 

 prevent natural infection by the administration of the 

 goat's serum. To test this, Experimental horses (Nos. 

 500, 516 and 553) received the goat's serum before they 

 were pastured with the patients. All the experimental 

 horses became ill. 



2. A pig received the virulent serum and its blood 

 was drawn on the third day and again after one month. 

 Each time it was inoculated into healthy horses (Nos. 53 

 and 85), which became ill will a period of incubation 

 of 30-40 days. Thus it was ascertained that the 

 virus could not be attenuated by passing through the 

 pig, and that the material that had been obtained from 

 the pig, therefore, could not be used in prophylactic 

 inoculation. 



3. A calf that had been inoculated with the virulent 

 blood was killed. Its serum and bile were then inoculat- 

 ed into heathly horses with negative results. One in- 

 stance of this experiment is as follows : — 



On August 22, 1911, 50 c.c. of the virulent serum 

 was inoculated into a calf. After 26 days it was killed 

 and its blood and bile were drawn. 



Experimental horse No. 112 received 40.0 c.c. of, 



