1907.] Experimental Treatment of Trypanosomasis in Rats. 3 
these rats this was the only lesion found post mortem. This will be referred 
to later in mentioning further treatment with mercury. 
Atoxyl and Calomel. 
Twelve rats have been treated with atoxyl (three to five doses) and then 
with subcutaneous and intramuscular injections of calomel, in doses of 
1 minim of Surgeon-Major Lambkin’s formula. It is difficult in rats 
to make the injection into the muscles, and in all cases necrosis occurred at 
the site of the injection; no better result was attained than by treatment 
with atoxyl alone, with subsequent recurrences and death. 
Atoxyl and Succonimide of Mercury. 
Further experiments have been made with this combination, in which the 
dose of the mercury salt has been increased up to 1 milligramme. The 
12 rats of this series are all dead, and showed acute kidney changes: 
inflammation, going on to necrosis of the epithelium, multiple heemor- 
rhages, ete. 
Atoxyl and Donovan's Solution. 
Nine further experiments have been made with this combination, also in 
larger doses; but these larger doses have been invariably fatal, with lesions 
both of the intestines and kidneys. The doses were arranged upon the 
basis of the doses recorded, with such good results, by Drs. Moore, 
Nierenstein, and Todd;* but one of us has received a letter, since the 
experiments were completed, from Dr. Nierenstein, stating that the Donovan’s 
solution used in their experiments was diluted with an equal part of water. 
Atoxyl and Lng. Hydrarg. Perchlor. 
A series of 12 rats was treated with this combination on the lines laid 
down in the paper above referred to, by Drs. Moore, Nierenstein, and Todd. 
The results obtained by them gave much hope that this combination would 
be especially useful. But we have not been able to get such good results. 
Out of 12 rats so treated only one is alive at the 97th day, the others 
having died with acute renal lesions. Of course, really comparative results 
are always difficult to obtain, and in rats the individual equation, with 
regard to dosage, and to resistance both to drugs and to disease, is a very 
varying one. We have, for instance, found, with the rats we have used, that 
the white ones are more susceptible both to diseases other than trypano- 
somiasis and to drugs than the black and white ones are; and we find the 
grey are the least susceptible. 
* “On the Treatment of Trypanosomiasis by Atoxy]l ..... followed by a Mercurial 
Salt, etc.,” ‘Biochemical Journal,’ vol. 2, Nos. 5 and 6. 
Bao 
