II 
Vol. VII, April, 1907), describes how he treated mice infected with 
T. dimorphon and 54 Benzidine colours. He finds, in contradiction 
to Mesnil. Nicolle and Aubert, that the red colours have a more 
powerful effect on T. dimorphon than the blue ones. 
Plimmer and THOMSON have used Mesnil’s, Nicolle’s and 
Aubert’s Cl. colour {p. di-chloro-benzidinc + Ac. H) and obtained the 
same results as with Trypan-red 
Koch, in a paper entitled ‘ Schlussbericht ii. d. Thatigkeit d 
deutschen Expedition z. Erforschung der Schlafkrankheit ’ (Deut 
med Wochenschrift, No. 46, 1907), states that Afridol blue and 
Afridol violet had not the least effect upon trypanosomes, neither 
had para-Fuchsin nor para-Rose aniline. 
C. Browning, ‘ Experimental Chemotherapy in Trypanosome 
infections ’ (Brit. Med Jour, No. 2,446, November i6th, 1907, p. 1405). 
gives the results of colour treatment, especially with para-Fuchsin. 
He recommends treatment with Atoxyl and Dye. 
YakimOFF, ‘ Zur Behandlung der Dourine ’ (Centralbl. f. Bakt. 
Orig., Vol. XLV, h. 5, Dec. ’07) used Trypan-red for treatment of 
Dourine in mice, rats and rabbits. Several injections of Trypan-red 
are able to prevent relapses in mice and to effect a cure. During the 
incubation period, if Trypan-red is given very early, the appearance 
of trypanosomes is prevented. 
It does not act prophylactically, and there is no immunity after 
cure. The mechanism of Trypan-red action is trypanolytic, 
trypanosomes being killed by Trypan-red by immune substances and 
other products. The immunity, however, is of very short standing. 
Thomas in his paper referred to above, and published May, 1905, 
states that after the publication of Ehrlich’s and Shiga s results wffh 
Trypan-red, he repeated the experiments with animals infected with 
different species of trypanosomes. ‘ The best results were obtained 
with mal de Caderas-infected animals; the results were not so good 
with animals infected with nagana and surra, and still worse in the 
case of animals infected with dourine, the Gambian horse strain, and 
T. gambiense. The parasites disappear for a few days to reappear, 
and the duration of the disease was not greatly prolonged, and on 
analysing the evidence given above of those who have carefully 
experimented with the aniline dyes, we are driven to conclude that 
the colours do not possess any advantage over the arsenic salts, that 
