1910.] Treatment of Animals infected with Trypanosomes. 283 
animals in the cold were livelier and took their food better than those in the 
animal house. We conclude that in our experiments the guinea-pigs had 
the incubation period delayed, and the life of the animal was prolonged in 
the cold. 
We now experimented with rats. Again we used both strains of trypano- 
somes. Five rats were inoculated with the old laboratory strain of 
T. gambiense, three were treated in the animal house, and two were treated 
in the cold. Three rats were inoculated with Rhodesian strain. ‘T’'wo were 
treated in the animal house and one was treated in the cold. Here we find 
the average incubation period in the cold was 6°3 days, and the incubation in 
the animal house was 4°8 days. The average life in the cold was 16°3 days 
and the average in the animal house was 14:2 days. Daily enumerations 
were carried out in all the above animals. The conclusions to be drawn 
from the above are therefore in favour of treatment in the cold. The 
resistance of the animal body is evidently raised, for the incubation is 
delayed and life is prolonged. 
In favour of the cold we have also the evidence of the patient W. A., who 
said he felt better in the cold chamber, and, lastly, all visitors to the cold 
chamber testified as to its bracing effect. What the physiological action of 
the cold is we are not prepared to state at present; but we certainly think 
that animals treated were beneficially affected, and that they were livelier. 
We think the cold dry atmosphere, which has been compared to the climate 
of Canada or Switzerland, raises the vitality of the whole animal organism 
and thus acted as a valuable therapeutic agent in treatment of Sleeping 
Sickness. 
We did not cure the disease, but we were enabled to prolong life, and so 
we must regard the treatment as a valuable help in patients suffering from 
trypanosomiasis. Adding these results in animals to those previously 
reported by Major Williams, the combined series of animals experimented 
EEon show very similar results. 
/ 
! IV. Treatment with X-rays. 
A, young piebald rat, weighing 77 grammes, was inoculated with the 
Rhodesian strain of trypanosomes. Here we have to thank Dr. Morgan, in 
charge of the Electrical Department at the Royal Southern Hospital, who 
kindly advised us in the administration of the rays. The exposures were 
given by Miss Wells, an experienced worker in electrical treatment, and we 
have to thank her for her kind assistance. 
The rat lived 15 days, and we can therefore say that this animal’s life was 
