TRYPANOSOMES, TRYPANOSOMIASIS, AND SLEEPING SICKNESS 59 
parasites are present in the peripheral blood very little benefit occurs from a 
continuance of this treatment. 
T\ dimorphon. — The dye exerts a slight influence on this parasite, the numbers 
in the blood diminish, and many deformed ones are seen after a tew days ; the 
organisms increase in numbers. In a tew instances the parasites are absent from the 
peripheral circulation for a short time. Dogs show only transient improvement 
with a diminution of the parasites followed by a rapid increase in their numbers ; 
this phase lasts a few days only. Rats and mice show a temporary reaction, their 
lives may be prolonged for fourteen days ; at times the treated ones appear to 
succumb more quickly than the non-treated controls. 
Rabbits and Guinea-Pigs. — The same temporary benefits are derived from 
injection of this dye. 
Testing the action of the dye on the parasite by the addition of some of the 
solution to defibrinated blood containing trypanosomes, shows that with all of the 
different pathogenic trypanosomes a slight microbicidal action is manifested. The 
contact must be tor some hours before the action will be noted ; it is, however, a 
definite action as control tubes show. Ehrlich and Shiga record the preliminary 
injection of animals with trypanroth, and after a few days injecting the animal with 
some virulent blood. They believe that the dye forms anti-bodies. A goat was 
therefore regularly injected with the dye, and after some weeks some of the blood was 
drawn off ; at first it was noted that the action of the serum did not differ from 
normal goat serum. As the animal got more under the influence ot the dye it was 
noted that contact of living trypanosomes with this serum produced deleterious effects on 
the parasites which very often became deformed. If some of this serum was injected 
into mice with T. equinum a diminution in the number of the parasites was noted. 
Unfortunately, the injection of this dye for a long period caused the goat to become 
very run down, and the regular injection for a time had to be stopped. On the goat 
regaining its health it was once more given a course of injections with the dye. The 
serum had the same effects. In four mice the administration of this serum has 
prolonged the lives of the animals for thirty-one to forty-eight days. The serum is 
of a light, clear, fuchsin-red colour after five grammes have been given the goat. The 
amount of serum necessary is about i*o c.c. for a mouse ot twenty-two grammes 
weight. As more ot the dye is injected the amount ot serum necessary is lessened. 
The experiments are too few in number to possess any practical worth. As the 
sodium arseniate and trypanroth had proved of use a combination of these two 
substances was tried for ten months. 
Atoxyl-trypanroth combination has proved of benefit. With animals infected 
with T. dimorphon the results are more promising than in controls treated with either 
of these drugs separately. The parasites disappear rapidly, remain absent if the 
administration of the arsenic and the dye is pushed ; the animal increases in weight ; 
