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 powerful!}' 

 is probably due to the fact, that free cyanogen can directly act 

 upon proteids in solution, 1 ' 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, 1S85, Bd. 15, S. 155). 



