Reasons for 

 employing 



154 TRYPANOSOMIASIS IN THE ANOLO-EOYI'TIAN SUDAN 



occurroil tn mo that it mi^'lit lie well to test tho tliciaiMiitir action of another anilin colour, 

 /.'•., chrvsoidiiic, the hyiinichloridc of rii-uiiiido-azo-bi'nzene (C,j H,, N4 HCl.). Though 

 I liail no proof of its value yit I lunl ohtained gomewhat suggestive results with it in 

 <-oii(litions other than trypanosomiasis. Tims, some years ago. I fouinl that it was extremely 

 lethal to fish even in very dilute solutions. Further, of all the dyes used in experimenting 

 it seemed to have the greatest penetrating jiower. appeareil to pass very readily into the 

 lilood stream, and iiiidoulitedly possessed a marked athnity for the central nervous system, 

 chrysoidine staining the bruiii and spinal cord a hrilliant yellow colour. Although so toxic to fish, 

 comparatively large doses could he given with impunity to raldiits. Wevl,' who experimented 

 with dogs, regards chrysoidine as non-poisonous, hut states that it causes a notable reduction 

 in liody-weight and slight aibitiiiinuria. Its toxic action on tish probably depends on its 

 being an azo compouml. but its effects were very similar to those of methylene blue. It 

 proved, however, more poisonous and more speedy in action. As methylene blue is known 

 to benefit cases of bilharzia disease and to exercise a lethal effect on the ciliated embryo of 

 S<-histiiK(>iiiii)t, /i,ini>i/i>/>iiiin, 1 first of all tested chrysoidine on this myracidium and found 

 that in a strength of 1 in 20,000 the dye killed the embryo practically instantaneously, 

 while a solution of 1 in 200,000 proved lethal in 17 minutes. Keniembering that methylene 

 blue has been exiiibitcd witli some benefit in malaria, it seemed to me that possibly 

 chrysoidine might be found bi ncfic jal in cases liarbouring protozoal blooil parasites. Further, 

 its aftinity for the nervous system seenieil to point to a possible value in a disease like 

 trypanosomiasis where the late and really lethal effects are pro<luced by an invasion of the 

 eerebro-spinal system— at least, such is the view at present held as regards human 

 trypanosomiasis. I admit such reasoning is none too conclusive, or even hopeful, but many 

 tlrugs have been tried in many diseases with still less reason and often merely empirically. 



Dr. Slictlield Neave, impressed by the experiments on bilharzia embryos and acting 

 wholly on his own initiative, took some of the dye up the White Nile with him and had an 

 opportunity of testing the drug on a ease of human trypanosomiasis, the history of which will 

 be found fully detailcil later. Jleanwhile. I proceeded to carrv out .some tests in vitro, 

 mploying Jlenk's product, a black or dark purple, shining crystalline powder which is 

 somewhat insoluble, 1 gram in 10 e.c. distilled water constituting a .saturated solution 

 which is of an intense orange reil colour. 

 Experiments in Such a Solution addid to trypauosonie infected IjIoimI in a proportion of 1 to 500, killed 



all the trypanosomes present practically instantaneously. They weri' stained slightly by the 

 yi How dye. On staining such dead trypanosomes by the liomanow.sky method they were 

 found to take the colour badly, and to have swollen posterior ends. They looked as if they 

 had shrunk into them.selves. 



In a strength of 1 to 6,UUt) some try}»anosomes were observed to die in five minutes. 

 Others, though retaining their motility, became rounded, and these also die<l after forty-five 

 minutes. After four hours only one living trypauosonie could be found. Though lively it 

 had changed in shape, and looked like an involution form. Although weaker mixtures, even 

 1 in 30,000. killed some of the parasites, many were found to survive. In all cases controls 

 were performed, and the blood was mixed with sterile citrate solution. No agglutination was 

 observed. The dye was not so lethal as I had hoped, but I resolved to give it a trial. The 

 following are the records of cases treated with it. 



• The Sniiitary Kclntioii of the Coal Tnr Colours (Lcffmnii). p. liC. 



e: 



viiro 



