3 
it seemed probable therefore that the disease would be prevented 
altogether if the Arsenic were given for some time previous to the 
animals being exposed to the infection, 
From experiments set on foot to determine whether Arsenic had 
a prophylactic action, he concludes that it would be quite useless 
as a prophylactic agent, but that it was useful in prolonging life, 
and especially in the ‘ Fly Country, after the disease had begun. 
Following upon Bruce’s observations come those of LiNGARD (1893). 
Lingard (Report on Horse Surra, vol. I, p. 104, 1893) mentions 
in connection with his experimental enquiry into the treatment of 
Surra, that Pottinger had tried Arsenic without any appreciable 
effect Lingard then conducted himself a series of experiments upon 
numerous animals with Arsenic compounds. Cinchona alkaloids. 
Arsenic alone, and also Mercury perchloride. The results showed in 
the case of Mercury perchloride that there was no diminution in the 
number or activity of the parasites in the blood, and that they 
continued to be present in the blood for three days following the 
injection of the drug. ^ 
With reg-ard to the treatment with Cinchona alkaloids Combined treat- 
® ---1 t . ni^flt with Axscnic 
Arsenic, we quote Lingard's own words ( 1 . c.): — in the case or two^j the Cinchona 
animals, it was decided to attempt curative treatment, although it 
was recognised that the animal had already been suffering from the 
disease for a period of at least twenty-three days. It was thought 
advisable to commence the treatment when the number of haematozoa 
in the blood should be on the decline, and accordingly on the 14th 
June, the haematozoa being few, treatment with Cinchona alkaloids 
and Arsenic in large doses was commenced. On the 20th the 
haematozoa disappeared from the blood, but the temperature and 
respirations remained above normal. The general symptoms of Surra 
increased up to the 24th; oedema and swelling of the limbs, sheath 
and under the abdomen increased in extent. The animal steadily 
losing condition, the muscles wasting, and the gait staggering and 
uncertain. On the 25th the animal had decidedly improved, and it 
was noticed that the oedema of the sheath and abdomen was 
distinctly less in amount; the animal seemed brighter and moved 
freely about the loose box. 
‘This amelioration of the symptoms was gradually progressive, 
and on the 2nd July the oedema under the belly had completely 
