12 
they are not even as efficacious.’ In other words, sodium arseniate 
had given better results and still held out to investigators a more 
promising field for ultimate success than the use of colours. 
Use of the com- However, following up the experiments of Laveran. Thomas 
Arsenic and colours determined to try a combination of the two drugs Trypan-reii and 
Arsenic- and the results were more encouraging, but he states, 
‘ unfortunately trypan-red also caused a nephritis, and by its chemi- 
otaxic properties very extensive necrosis sometimes resulted. On 
monkeys, especially, the subcutaneous injection of the dye either 
alone or in combination with arsenious acid induced ulceration, which 
so undermined the health of the animals that they succumbed to any 
outbreak of disease, which occurred only too frequently amongst my 
animals. It was these untoward accidents which induced me to seek 
a preparation of arsenic less toxic and the subcutaneous injection of 
which entailed less danger of necrosis! Before, however, proceeding 
to describe the compound of arsenic {Atoxyl), which he demonstrated 
had such a marked action upon the trypanosome, we wish to record 
the observations made upon the combination of Arsenic with colours 
and other bodies. 
Thomas and Breinl, in their publication referred to above, 
came to the conclusion 
‘ That in trypan-red we possess an agent of some use in the 
treatment of trypanosomiasis. That certain trypanosomic diseases 
appear to be more amenable to its action than others. That in the 
substance at present available there is need for improvement in order 
to abolish its toxic effects. 
'That a combination of arsenic and of an improved form of 
trypan-red would seem indicated in the further investigation t.f the 
cure of trypanosomiasis.’ 
i-av^,KAN wrote a paper entitled ‘ Traitement mixte des Trvpano 
som,ases par lac.de arsenieux et le trypanroth des infections a, 
Trypanosoma gambiense: published 30th January, igo= in th, 
Comptes rendus de I’Acadeniie des Sciences. He was Uie first 
use a combination of trypan-red and arsenious acid. He made a 
hirmoTor “■“'’mation, and we owe t< 
.1. — rr“r„;: 
