Gr. H. F. NtrTTALL AND S. HADWEN 
157 
that atoxyl treatment actually aggravated the symptoms of the malady. 
Although the prospect of finding a remedy which would exert any in¬ 
fluence upon the course of the disease appeared very doubtful, we 
nevertheless considered it desirable to continue these investigations. 
Our experiments were conducted in a similar manner to those de¬ 
tailed by Nuttall and Graham-Smith, and the same strain of P. canis 
was used. Our Cambridge strain has been maintained for a consider¬ 
able time in the laboratory by inoculation from dog to dog and a long 
series of passages has in no way influenced its virulence. Animals 
which have been inoculated subcutaneously with the fresh defibrinated 
heart blood of a dog suffering from the disease are almost certain to die. 
From our laboratory experience, mainly with young dogs, we reckon 
upon a mortality of about 90°/o- The strain we used came originally 
from Cape Colony. We do not know the source of the strain used by 
Gonder, but we consider that the parasites he experimented with must 
have been much less virulent than ours, since two out of three of his 
control dogs recovered (all his atoxyl-treated dogs died). Our reason 
for making this statement is to show that we have been dealing with a 
very deadly disease. 
After the dogs had been inoculated with defibrinated or citrated 
blood, rich in parasites, they were kept under continuous observation, 
their blood, obtained by pricking an earvein, being periodically sub¬ 
mitted to microscopic examination, with a view to detecting the 
parasites. Drug treatment was usually commenced after the para¬ 
sites appeared in the blood. 
The drugs were prepared in watery solution and in most instances 
the solutions were injected subcutaneously. In the case of Trypanblau 
and Trypanrot, the dyes soon become diffused throughout the system as 
evidenced by the blue or red colouration of the animal’s skin and mucous 
membranes. Well-marked colouration was noticeable after 2—3 hours, 
and usually attained its maximum intensity after about 9 to 12 hours. 
Sometimes the drug injections produced local swellings, which generally 
subsided after a short interval of time; in other cases an abscess formed 
at the site of injection. The abscesses healed rapidly after they were 
lanced. 
Before describing the success we have obtained by means of Trypan¬ 
blau and Trypanrot treatment, we may as well mention that treatment 
with Arsacetin (Sodium-p-acetyl-aminophenylarsinate-acetylarsanilate) 
and Soamin (Sodium-para-amino-phenylarsonate) was without any effect 
upon the course of the disease. 
