Mr. A. lvliii'_ r t"ii. Mouth Af< // 



rin,riit* made in reynnl t<> /'/ ' 



The yellow fluid from the pericardium of an animal which had <lie<I 

 from the disease was filtered through a Pasteur filter. 100 c.c. of the 

 filtrate was injected suhcutaneously into a horse. Eleven days later it 

 was inoculated with 3 c.c. of preserved blood injected subcutaneously. 

 The result, which culminated in death from ordinary horse-sickness, 

 showed that no protective influence had been exerted by the filtered 

 fluid. 



Effect of Calomel. This drug, in doses of 30 to 60 grains daily, had 

 the effect of retarding death, and the blood of such animals drawn at 

 periods later than that at which death usually occurs was distinctly 

 weakened in virulence. Such blood has on several occasions, though 

 not in all, induced attacks of the disease, from which the animals not 

 only recovered, but acquired protection against virulent blood injected 

 subsequently. 



Transference of the Disease to other Animal*. 



(a.) Donkeys. The subcutaneous or intravenous inoculation of 

 donkeys with fresh virulent blood is followed by fever. The period of 

 onset is irregular and uncertain, while the duration of the febrile 

 period varies from one or two days to, in my experience, a week or 

 more. 



The amount of the virus used has some relation to the severity of 

 the fever, but the special susceptibility of the animal is the principal 

 factor in determining the degree and duration of the fever. 



Two donkeys, equal in age, were inoculated respectively with 1 c.c. 

 and 50 c.c. of the same blood. In both cases a moderately severe 

 reaction followed, and while the animal receiving the injection of 50 c.c. 

 was rather more severely affected than the other, the difference on the 

 whole was but slight. 



In all I have inoculated twelve donkeys, and, while none died, the 

 difference in susceptibility was most clearly demonstrated, some 

 scarcely showing any reaction at all. 



(b.) Cattle. The susceptibility of cattle to the inoculated disease is 

 excessively variable. I have inoculated twenty-one cattle. A definite 

 febrile reaction was produced in seven cases, and four died. 



In the case of one which died, and in which the symptoms produced 

 were quite characteristic of those found in horses, the inoculation of 

 its blood into a clean horse was followed by the usual period of incuba- 

 tion, the onset of fever, and death from characteristic horse-sickness. 



The disease known as Imapunga, which occurs to a limited extent 

 among cattle, presents features which in every respect are identical 

 with those produced in susceptible cattle by the inoculation of virulent 

 horse-sickness blood. 



