84 
Surra 
Atoxyl injected intravenously. 
Pony 
Weight 
Actual dose 
Dose per 500 lbs. 
no. 
lbs. 
gms. 
gms. 
Results 
36 
360 
1-20 
1-66 
Lived, no toxic effect. 
37 
283 
1-00 
1-76 
ff >> 
38 
630 
4-00 
3-17 
»» 
39 
630 
4-00 
3-17 
ff ff 
40 
564 
4-00 
3-54 
Lived, stood the dose on 
4 consecutive days. 
41 
678 
7-50 
5-53 
Lived. 
42 
574 
7-50 
6-53 
Death. 
43 
565 
7-50 
6-63 
J J 
44 
678 
10-00 
7-37 
J J 
The toxic dose is about 6 grus. per 500 lbs. 
Having determined the approximate toxic dose of the various arsenic 
preparations used, the results of administering full sub-toxic doses were 
investigated. 
Attention was directed to the following points. 
(1) The effect on trypanosomes and determination of the period during which the 
blood remained free from trypanosomes after a single sub-toxic dose of each drug. 
(2) The influence on the health and general condition of the animal. 
(3) The comparison of the results produced by drugs administered by various 
channels (subcutaneously, intravenously and by the mouth). 
(4) The effect of varying the interval between successive doses. 
(5) The effect of combining various arsenic preparations, also of using arsenic in 
conjunction with other drugs. 
The results are detailed in the data and tables following. 
Treatment with atoxyl alone. 
The value of a single dose of atoxyl injected subcutaneously. This 
has been estimated by the period during which the peripheral circula¬ 
tion remained free from trypanosomes. The atoxyl was administered at 
a period of paroxysm when the trypanosomes were numerous in the 
blood. 
Pony 
no. 
Weight 
lbs. 
Dose 
Period during which blood 
remained free from trypanosomes 
45 
250 
30 c.c. 
4 °/o sol. 
9 days. 
46 
660 
60 „ 
12 „ 
5 „ 
47 
300 
150 „ 
2 „ 
6 „ 
47 
300 
200 ,, 
2 „ 
7 „ 
47 
300 
100 „ 
2 „ 
4 „ 
48 
450 
100 „ 
2 „ 
6 „ 
48 
450 
200 „ 
2 „ 
7 „ 
49 
500 
100 „ 
2 „ 
3 „ 
49 
500 
150 „ 
2 ,, 
5 ,, 
49 
500 
200 „ 
2 „ 
8 „ 
A full dose of atoxyl, injected subcutaneously, freed the circulation 
from trypanosomes for 3 to 9 days. 
