144 Proceedings of the Royal Society of Edinburgh. [Sess. 
The tubes were incubated for an hour at 37° C. The contents of the tubes 
were therefore in other respects the same, except that one contained harma- 
line and the other not. The object was to determine whether this exposure 
to harmaline so diminished the vitality of the organisms as to render them 
less virulent. 
Two rats belonging to the same litter and each weighing 29 grammes 
were selected ; one received by subcutaneous injection the contents of tube 
A, and the other the contents of tube B. Both rats died on the fifth day 
after injection, the blood in each being found to swarm with trypanosomes. 
There was therefore no appreciable diminution in virulence of the trypano- 
somes produced by exposure to harmaline 1 in 3000 for one hour at blood 
temperature. 
(c) In a second type of experiment two rats of the same weight were 
injected each with 1 c.c. of the same mixture of surra blood in citrated 
saline, the injections being given subcutaneously into the right flank. One 
of them received at the same time a dose of harmaline hydrochloride 0-025 
gramme per kilogramme, or one-quarter of the minimum lethal dose, the 
injection being given into the left flank. Both rats died on the sixth day 
after injection, with their blood thronged with trypanosomes. This dose of 
harmaline, proportionately as large as one would probably care to employ 
therapeutically, had no effect in preventing death from this infection with 
trypanosomes. 
It is clear from these experiments that, though harmaline does have a 
toxic action on Trypanosoma Evansi, this action is not sufficiently powerful 
to suggest that it would be of practical use in the treatment of diseases due 
to this type of organism. Possibly better results might have been obtained 
if the infected rat in the third experiment had received daily-repeated 
injections of harmaline rather than one single dose on the first day ; because 
in the last three days there would be little harmaline left in the blood. But 
at the time it seemed hardly worth while to prosecute the experiments 
further, especially as alkaloids of the quinine type have not so far proved of 
much value in the treatment of diseases due to trypanosomes.* 
* Since the above was written, my friend Mr Hilton-Simpson has kindly shown me the 
unpublished notes recently collected by him on the native medicines used by the inhabitants 
of Shawia, in Algeria. Of special interest in connection with this communication are the 
observations he has made on the uses of Peganum harmala , of which observations the 
following is an extract : — 
“ Seeds of Peganum harmala are collected in summer and can be kept for four years, but 
not longer, because after that they deteriorate, These serve for a variety of treatments and 
are the best remedy for syphilis. The seeds are ground to a very fine powder and made into 
pills with honey, and one pill is taken night and morning for fifteen days, when a cure is 
affected : a purge, preferably castor oil, is taken before the treatment begins. This ‘ harmel 
