ON THE POISONOUS ACTION OF DI-CYANOGEN. 
41 
hydrocyanic acid acts about 5 times stronger than di-cyanogen, 
seems to us exceptional. One experiment, which we made 
with two white rats, proved indeed that here hydrocyanic acid is 
much stronger. The one rat weighing 124 grams received by sub¬ 
cutaneous injection 1 c.c. of hydrocyanic acid solution 1 :10000, 
the other rat weighing 156 grams received an equally diluted 
solution of dicyanogen (1 c.c.). The former rat was found 
dead after 10 hours, the latter, however, remained alive and 
healthy. The fact that the di-cyanogen here acts less powerfully 
is probably due to the fact, that free cyanogen can directly act 
upon proteids in solution,^ and therefore can be changed to a 
great extent in the blood and lymph, before it reaches the 
nervous centres. Hydrocyanic acid does not act at all upon the 
ordinary passive proteids, and can, therefore, without being pre¬ 
vented by the serum albumen, reach the nervous centres,and act 
there upon the active labil proteids of the living protoplasm. 
As the general result we see, that the prediction that free 
cyanogen would prove a general poison for all kinds of living 
organisms, has been confirmed. At the same time, it has been 
shown that also hydrocyanic acid is a general poison and we 
hope therefore that the explanation, which we have given 
above, will prove more durable than the former unsatisfactory 
hypotheses. 
1) Compare: O. Loew, on the action of di-cyanogen upon albumen, Journ. f. 
prakt. Chem., 1877. 
2) The former hypothesis that hydrocyanic acid acts poisonously merely on ac¬ 
count of combining with the haemoglobin has been proved erroneous (J. Belky, 
Jahresb. f. Thierchemie, 1885, Bd. 15, S. 155). 
