of hydrocyanic acid may perhaps be found in the comparison of the 
effects of these two poisons upon sulphur metabolism. In the pub- 
lication referred to above it was stated that under the influence of 
acetonitrile the “ percentage of sulphur excreted as neutral sulphur 
frequently rose from 25 to 65 or more; the total excretion was not 
much changed, but the oxidized sulphur frequently almost disap- 
peared.” Results very similar to the above have recently been 
obtained by Richards and Wallace , a and by Loewy, Wolf, and 
Oesterberg 6 with potassium cyanide and hydrocyanic acid. 
Richards and Wallace found in one experiment upon a dog poisoned 
with potassium cyanide that while the total amount of sulphur 
ehminated remained unchanged the percentage ehminated in the 
oxidized state was 64.53 on the normal da,y and 48.78 on the day of 
poisoning. Loewy, Wolf, and Oesterberg found that in severe 
poisoning by hydrocyanic acid the sulphur ehminated as neutral 
sulphur increased from 28.6 per cent to 54.8 per cent. The greater 
effect upon the sulphur metabolism observed in our experiments 
was probably due to a more prolonged action of the hydrocyanic 
acid. 
As has been already stated, the administration of thyroid causes 
marked changes in the susceptibility of animals to acetonitrile. 
Since thyroid does not alter the resistance of animals (or at least of 
mice) to hydrocyanic acid, c it may be concluded that its action is 
exerted chiefly upon the processes by which acetonitrile is decom- 
posed in the body and not upon the hydrocyanic acid which is formed 
from it. In fact, acetonitrile seems to be a very delicate test for 
detecting changes in metabolism brought about not only by the 
thyroid and certain other organ products, d but by different diets/ 
inanition, etc. 
a Experiments on Mice. 
Preliminary experiments and theoretical considerations . — When small 
amounts of thyroid are fed to mice for a few days these animals 
acquire a markedly increased resistance to acetonitrile. This is 
true not only for white but also for wild gray mice, although most of 
the experiments were performed upon the former, and unless other- 
wise stated, white mice are referred to in all of the following experi- 
ments. 
The following results may be quoted to illustrate from what large 
amounts of acetonitrile mice which have received small amounts of 
a A. N. Richards and G. B. Wallace, J. Biol. Chem., 1908, 4, p. 179. 
b A. Loewy, C. G. L. Wolf, and E. Oesterberg, Biochem. Ztschr., 1908, 8, p. 132. 
c R. Hunt, J. Biol. Chem., 1906, 1, p. 42. 
d J. Am. M. Ass., 1907, 49, p. 1325. 
e Proc. Soc. Exper. Biol, and Med., 1906, 3, p. 15. These results will soon be 
published in detail. 
