989 
The Experimental Treatment of Trypanosomiasis in Animals. 
y 
By H. Wotrerstan Tuomas, M.D., C.M. (McGill), (J. H. Todd Memorial 
Fellow in Tropical Medicine), Liverpool School of Tropical Medicine, 
Johnston Tropical Laboratory, University, Liverpool. 
(Communicated by Professor R. Boyce, F.R.S. Received April 8,—Read 
May 11, 1905.) 
Numerous drugs have been tried in endeavouring to find a therapeutical 
agent which would cause trypanosomes to disappear from the blood. Of all 
those tried, arsenic and trypan red are the only ones exhibiting a marked 
influence on the parasites. 
On account of the liability of the appearance of toxic symptoms, the 
proneness to sloughing at the site of inoculation, and the oftentimes 
considerable disturbance which occurred after the subcutaneous administra- 
tion of sodium arseniate, I decided to try if other compounds would be more 
satisfactory in the treatment of trypanosomiasis. The arsenic preparation 
which has given the best results is a compound of arsenic and aniline 
C,H;No,As (meta-arsensaure anilid, atoxyl), a preparation which has of 
recent years been used intravenously and subcutaneously in the treatment 
of skin diseases and anzemia. 
The effect of this preparation in the treatment of trypanosomiasis has 
been observed in an extensive series of experiments during the last 10 
months. 
Strains used. 
T. gambiense-—Five strains. A very virulent one obtained from one of 
my cases of Sleeping Sickness—this strain exhibited nothing abnormal in its 
direct passage ‘through a monkey, but after infecting a baboon (Cynocephalus 
babuin), and then passing into a rabbit, it became abnormally virulent. 
T. evansi.cSurra. 7. equinwm.—Mal de Caderas. T°. brucet.——Nagana. 
T. equiperdum.—Dourine. 7. dimorphon.—Gambian horse. 
No animal was treated until a large number of parasites were observed 
in the blood and definite signs of anemia and loss of weight determined. 
Many of the animals were not treated until several months after infection 
had occurred. 
Four methods of treatment were adopted— 
(a) Atoxyl—hich doses at intervals of a week. 
(6b) Atoxyl—high initial dose and then reduced amounts administered three 
times a week. 
