26b 
I. INTRODUCTION 
This paper is a continuation of the experimental work on the 
treatment of experimental trypanosomiasis already published by 
US.1- 2 
The technique of the present series of experiments was the same 
as employed in our former work. Trypanosoma brucei was again 
used in all of our experiments, unless it is otherwise specified, 
because of its great virulence for experimental animals, which makes 
it possible for conclusions to be drawn more quickly and more 
certainly from work done with it than is the case with any other 
pathogenic trypanosome. 
The strain with which w'e worked killed untreated rats in from 
three to five or seven days. In each series of experiments described, 
animals of about equal body w’eight were used as far as possible. 
All inoculations were made subcutaneously with blood mixed with 
Sodium citrate solution in saline, and approximately equal quantities 
of blood were used in every inoculation of animals of the same species 
where results were required for the comparison of different drugs 
The usual quantity of infecting blood inoculated varied from i c.cm- 
to 5 c.cm. for rats to from 2 c.cm. to 5 c.cm. for guinea pigs and as 
much as 10 c.cm. for donkeys. The strain which was used for 
infecting purposes was always kept going in untreated animals, and 
therefore there is no possibility of a resistance to drugs, acquired by 
the trypanosomes, having militated against the success of our 
experiments. 
Treatment was commenced in no instance before there were 
e nite signs of a well-established infection, such as the constant 
presence of the parasites in the peripheral circulation of the infected 
anrmal.i2 it may be noted here that, however valuable they may be 
as an indication of the trypanocidal value of the drugs used, 
'penments, in which treatment is commenced on the first or second 
f ^ L of the trypanosomes in the blood, and 
ere ore, before the infection is well-established, are, for practical 
purposes, valueless. Because, to give but one reason, it would 
j c. practically impossible to treat a naturally 
th-.t^' ^ disease. We suspect 
ear y infections are so much the more easily treated not only 
