10 
Mesnil and NiCOLLE, ‘ Traitement des 'I rypanosomiases par les 
couleurs de benzidine ’ (Premiere partie, etude chimique. Secondc 
partie, etude experimentale. Annales de I’Institut Pasteur, Tome XX, 
June, July, 1906), tried to find out the connection between the 
chemical constitution and the trypanocidal action of the benxulint 
colours. P. di-antido-diphenyl urea + Ac. H. (^Pb.) and p. di-chhro- 
benzidine Ac. H. {Cl.) were the only colours which showed any 
marked action on the trypanosomes. Amongst the Arsenic 
preparations with which they experimented Atoxyl was found to l>e 
the most efficient. 
Mesnil, Nicolle and Aubert (Annales de I’lnstitut Pasteur. 
January, 1907) give their experiments upon, amongst other drugs, 
the benzidine colours, and state that the blue colours are superior to 
the red colours, their best results being obtained with p. di-amido- 
diphenyl urea + Ac. H. (Ph.). 
Mesnil and Nicolle (Annales de I’lnstitut Pasteur, December, 
1907) describe in a third paper the final results of their experiments 
in the case of twelve monkeys infected with T. gambiense, of which 
six were cured by Atoxyl alone, four by the combined treatment of 
Atoxyl and Ph., and two by Ph., first employed alone, followed up by 
only one injection of Atoxyl in the first case, and two in the second. 
Ehrlich, in a paper entitled ‘ Chemotherapeutische Trypano- 
somenstudien' (Berl. klin. Wochenschrift, Nos. 9-12, 1907), says 
Benzidine colours {Trypan-red), Tripkenylmeihane colours {Brilliant 
green and Malachite green, Wendelstadt and Fellmer) have been 
found to be trypanocidal Ehrlich experimented with Parafuchsin 
by feeding mice on parafuchsin cakes, which gave very good results. 
Weber and Krause, in a paper entitled ' Farbstoffbehandlung 
der kunsthchen Trypanosomeninfektion ’ (Berliner klinische Wochen- 
schnft No. 7 1907), tested systematically different colouring matters 
{Crystal vtolet. Vtctoria blue, Fuchsin), as regards them trypanocidal 
acfon m Ngana, wtth the vrew to find relations between chemical 
constitution and action. Fuchsin seemed to have the best effect also 
cause of its relative harmlessness for animals. They were unable 
o obtain cures, but the advantage of Fuchsin seems to reside in its 
power of prevention resiae m its 
