EFFECTS OF AESENIC IN HOESES. 283 



" This horse remained alive sixty -five clays from the com- 

 mencement of the disease, and then only succumbed to Horse 

 Sickness. While under arsenic he very fairly retained his 

 strength, as may be proved by the fact that he very often carried 

 me (riding over fourteen stone) down to the Fly Country and 

 back, when I went down to collect flies. This means being 

 on the march from 5 a.m. until 5 p.m., with a climb in the 

 afternoon of the Ubombo, which is some 2,000 feet above the 

 plain." 



Exp. 224. — (This horse likewise eventually succumbed to 

 Horse Sickness.) 



" It is evident that the arsenic had much less effect than in 

 the previous case (Exp. 205a)." 



Exp. 264.—" Horse, Bay.—' M.D.' " 



" Bemaris. — This case illustrates the uselessness of arsenic 

 as a means of preventing "Fly Disease." Although " M.D." was 

 well saturated with arsenic and smelt strongly of it, two short 

 exposures to the " Fly " were sufficient to set up the disease. The 

 first exposure was at Mkusi Drift, at the western end of the 

 Mkusi poort, a drift which has usually been considered free 

 from " Fly." This year many Tsetse-flies have been seen there, 

 and several cases of Nagana have occurred among the animals 

 crossing the Segane Valley to Ubombo. At the eastern end of 

 the poort, and within a couple of miles of the drift, a herd of 

 buffaloes have their headquarters, so that it can readily be 

 understood how the flies find their way to the drift. As will be 

 seen from the temperature chart, the arsenic has held the disease 

 in check for some two months, but not sufficiently to prevent the 

 right eye from becoming affected by an opacity causing blindness. 

 The hsematozoa are now beginning to reassert themselves, and 

 the case will probably end fatally in a few weeks." [The horse 

 eventually became unable to stand, or to rise, and was therefore 

 shot.] 



Exp. 278. — "Another case showing the futility of arsenic as 

 a prophylactic agent." 



Exp. 283. — " In this case arsenic is seen to be practically 

 useless, both as a prophylactic and a curative agent." 



" (2.) Treatment in Donlceys " (pp. 56-64). 



" The donkeys were given arsenic in the dry condition, the 

 mouth being opened by an assistant and the powder placed on 

 the back of the tongue. There is no difficulty in administering 

 it in this way " (p. 57). 



In the five cases described all the donkeys, except one, 

 eventually succumbed to the disease. 



In " Remarks" on Exp. 257 the author writes : — " This case 

 shows in a marked manner the effect of arsenic in prolonging life 

 in this disease" (p. 61). 



