488 
and to try the effect of small doses of atoxyl in these animals with 
a view to determine the effect of that drug on this particular 
trypanosome which, as will be seen from the accompanying paper 
on ' Enumerative Methods in Untreated Animals ’ (H. B. Fantham 
and J. G. Thomson"*), was of extraordinary virulence. Various doses 
of atoxyl are recommended in treatment of human trypanosomiasis, 
and we find that the patient, W.A., in the Royal Southern Hospital, 
received four grains as a maximum dose. It was impossible in the 
case of this patient to push the drug further as he quickly showed 
signs of the toxic action of the drug. Louis Martin and Henri 
Darret, in an article on the treatment of sleeping sickness at the 
Pasteur Hospital, believe that atoxyl can cure light forms of the 
disease, and even severe forms, but that it is often necessary to give 
large doses, viz., one gram, which imperil vision. These authors 
however, still admit that permanent cure is a doubtful matter. 
In the experiments made by us we attempted, as far as possible, 
to administer a therapeutic dose of atoxyl. We first sub-inoculated 
four rats subcutaneously with T. rhodesiense. The lightest in 
weight, Rat 34, weighed 139 grains, and the heaviest weighed 256 
grams, namely, Rat 37. 
Colour 
Weight 
Inoculation 
period 
Duration 
of life 
Bat 34 
Piebald 
139 grams 
5 days 
27 days 
Animal House 
Bat 35 
Piebald 
.45 grams 
5 days 
26 days 
Cold Chamber 
Bat 36 
White 
25. grams 
6 days 
5 days 
27 days 
Cold Chamber 
Bat 37 
White 
256 grams 
8 days 
Animal House 
All the four rats were adults. Two were piebald and two white, 
and all received, subcutaneously, the same dose of trypanosomes, 
namely, 200,000. I wo of them, 35 and 36, were placed in the cold 
chamber, where the lowest temperature recorded was 20° F., and two 
were placed in the animal house. All these animals received atoxyl 
in solution subcutaneously in small repeated doses, which varied 
from to ^ of a grain. Take the body weight of a man as being 
V , *^ rOC - Ro > - - s °c-r B. ,Vol. LXXX 1 II, J 0 . 1, pp. 206-2r t . and Ann. Trop. Med. and Parant- 
\ol. IV, pp . 4.7-463. 
t Bulletin of Sleeping Sickness, Vol. 11 , No. .8, .910. 
