CONSTITUENT EESIDUES. 2Q 



Formulae At. Weights 



1 Oxalic acid C a H a 4 90 



2 Ammonia (H 3 N) HeN a 34 



C a H 8 N a 4 124 



4 Water (H a O) H 8 4 72 



i Cyanogen C a N a 52 



The formula for oxalic acid is C 2 H 2 O 4 , and its atomic weight 

 90. With this we combine 2 atoms, or 34 parts by weight, of 

 ammonia, H6N 2 . Adding these together, we get 124 for the 

 atomic weight of oxalate of ammonia. When from this we sub- 

 tract 4 atoms or 72 parts by weight of water, we have left only 

 2 atoms of carbon from the oxalic acid, and 2 atoms of nitrogen 

 from the ammonia, which exist united with one another to form 

 a double atom, or single molecule, of cyanogen gas, and amount 

 to only 52 parts out of 124, or to considerably less than half 

 the weight of the original compound. In cyanogen, then, the 

 only evidence of the original oxalic acid is carbon, and the only 

 evidence of the original ammonia is nitrogen. Nevertheless, the 

 constituent carbon and nitrogen of this remarkable gas, which in 

 so many of its properties resembles certain of the elementary 

 bodies, are not incorporated with one another, but remain apart, 

 in the same way as do the residues of saligenin and glucose in 

 salicin, and the residues of acetic acid and ammonia in aceto- 

 nitrile, thus : 



Cyanogen 



Accordingly we find that cyanogen gas, when dissolved in 

 water, gradually absorbs the water necessary to re-form oxalic 

 acid and ammonia, the entire molecules, of which the small resi- 

 dues of carbon and nitrogen are but the representatives. In 

 cyanogen gas, no matter how produced, there is a something, 

 however small, pertaining to oxalic acid, a something, however 



