58 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
hundred and seven days; in one case sixty-three days without any treatment being 
given, this rat died from broncho-pneumonia, its blood was non-infective. Mice have 
also shown the favourable results of this treatment, but they do not appear to be 
able to withstand large doses. 1 Rabbits and guinea-pigs inoculated with this substance 
have had their lives prolonged for a considerable time, the parasites disappear completely, 
and if the administration of the dye be continued the trypanosomes may not be seen 
for thirty to sixty days ; but the animal does not show the favourable reaction which 
attends the administration of arsenic, the anaemia is very little lessened, very often it 
is increased, the weight is not recovered, the temperature remains irregular. Very often 
if high doses are given toxic symptoms appear, these are characterized by more or less 
somnolence, the animals always appearing ' heavy,' there may be a slight discharge from 
the eyes. The face is often puffy, the urine in such cases usually has albumen ; after 
a time these symptoms wear off. They are especially marked in rabbits after 
intravenous injections. Rabbits can withstand intravenous injections of i*o to 2 - o c.c. 
of one per cent, solution, and it appears as it the administration through a vein gives 
better temporary results, as the parasites, even T. dimorphon, disappear more quickly 
than by the subcutaneous method. The disadvantage is that the anaemia appears more 
pronounced, and the toxic symptoms severer. No rabbit or guinea-pig has been 
definitely cured. 
Dogs and cats react fairly well to this dye, the life of the animal is prolonged, 
but no cure has been affected. Towards the last, despite repeated injections of this 
dye, the parasites continue to increase, the animal becomes a living skeleton, and 
usually develops a purulent discharge from the eyes and urethra. 
T. evansi) T. brucei. — Rats and mice inoculated with either of these parasites, 
and injected with this dye, live longer than infected controls. The disappearance of 
the parasite is only temporary ; alter four to six days the parasites reappear, and 
though they can be caused to disappear once or twice they sooner or later reappear, 
and the animal dies, sometimes at a time when only very few parasites are present in 
the blood. With Nagana and Surra, inoculated animals which have been treated 
have not lived over thirty days, the majority dying in fifteen to nineteen days. 
Rabbits and guinea-pigs react for a while, but the action on the parasites is not so 
marked as with Caderas infected animals. 
Dogs and Cats. — The same results as with rabbits and guinea-pigs, only a very 
short prolongation of the disease is observable. 
T. equiperdum. — The duration of the disease is only slightly affected by this 
dye. If injected early in the disease when the pup shows hardly any parasites a 
considerable prolongation of the animal's life occurs, but once large numbers of 
I. Extreme care has to be exercised in administering th : s solution. With rats and mice the preferable method seems to 
. be to inject into the thick muscles of the hind legs. The hair is shaved off and the part disinfected before the injection. Guinea- 
pigs and rabbits ought to be treated in the same way. Dogs and cats can be injected in the deep muscles of both fore and hind 
limbs, in the back, or in the loose tissue of the neck. Monkeys are difficult as the skin is extremely sensitive, but the thighs 
offer the best site for inoculation. 
