TRYPANOSOMES, TRYPANOSOMIASIS, AND SLEEPING SICKNESS 40 
VII. THE TREATMENT OK TRYPANOSOMIASIS 
Experiments have been conducted under this head on all the various trypanosomic 
diseases described in the previous investigations, and include T. brucei, T. evansi, 
T. equinum, T. equiperdum, T. dimorphon, T. gambiense (various strains). In 1902-1903, 
while Governors Fellow of Pathology at McGill University, one of us (H. W. T.) 
made experiments with sodium arseniate, etc., on animals infected with T. brucei and 
T. lewtsi. These tentative experiments have now been carried out on a large scale. 
As in the case of other workers we have tried a very large number of drugs to find 
them of no value in the treatment of infected animals. Wendelstadt, Lavek and 
Mesnil, Musgrave and Clegg, all give long lists of drugs and chemicals used with- 
out avail. These we have retested, and have tried in addition sodium, potassium, and 
ammonium fluoride, fluorescene, chrysoidin, and various preparations of silver and 
mercury, especially the newer compounds. The results have coincided with the findings 
of other investigators. Up to March, 1904, the only drug of any value was arsenic; 
Ehrlich and Shiga then published their results with a new dye named by them 
' Trypanroth,' and these two preparations are the only ones found to be of value in 
the treatment of trypanosomiasis. 
As animals have for a considerable period been known to be liable to infection 
with the various pathogenic trypanosomes, it was only natural to turn to the veterinary 
profession to see what drugs have in their hands proved of service in the treatment 
of these diseases. Of the countless drugs tried arsenic is the only one which has 
given encouraging results. Cases are on record where cures have been reported, but, 
on the other hand, many cases which have been treated by some form of arsenic and 
which have improved as long as the administration of the drug was kept up have 
shown parasites when it was discontinued and have succumbed to the infection. 
Bruce records cases in which large doses of sodium arseniate were given, and so long 
as the treatment was continued parasites were hardly ever found in the blood, the 
animal retained its strength and weight and was able to work, but on the treatment 
being discontinued the parasites quickly reappeared and the animal began to fail. 
Moore and Chichester report the effect of the intravenous inoculation of cattle, after 
dosage the animals regained their weight, the yield of milk which had diminished 
became normal and the parasites disappeared, whilst animals which had not been treated 
quickly died. We have, therefore, evidence that arsenic is of use in prolonging the 
life of the animal. Laveran, in 1902, reported his results in treating rats infected 
with the Nagana parasites. The life of the animal was prolonged, the parasites 
disappeared, and the animal seemed to have recovered. When treatment was 
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