318 CONSIDEKATIOX OF CARBOX COMPOUNDS. 



generally by treatment of the organic substance with concen- 

 trated nitric acid ; all these nitro-compounds are more or less 

 explosive. 



Cyanogen compounds contain nitrogen in the form of cya- 

 nogen, CN, a radical the compounds of which will be con- 

 sidered hereafter. 



Organic compounds containing nitrogen in the ammonia 

 form are known as amines or amides, organic bases or alkaloids. 

 (Albuminous substances also contain nitrogen in the ammonia 

 form.) 



Amines. Whenever the hydrogen of ammonia is replaced by 

 alcoholic radicals (or hydrocarbon residues) compounds are 

 formed which are termed amines. For instance : 



/H /C 2 H 5 /C 2 H 5 /C 2 H 5 



N_H, N H , N C 2 H 5 , N C 2 H 5 , 1ST C 2 H., 



\H \H \H \C 2 H 5 \C 4 H 9 

 Or 



NH 3 , N(C 2 H 5 )H 2 , N(C 2 H 5 ) 2 H, N(C 2 H 5 ) 3 , NCH 3 .C 2 H 5 .C 4 H 9 . 



Ammonia. Ethylamine. Diethylamine. Triethylamine. Methyl-ethyl-butylamine. 



Amines resemble ammonia in their chemical properties ; they 

 are, like ammonia, basic substances ; they combine with acids 

 directly and without elimination of water, thus : 



NH 4 + HCl = NH 4 C1; 

 N(C 2 H 5 ) 3 + HCl = N(CH)HC1. 



Triethylamine. Triethylammonium 



chloride. 



Amides are substances derived from ammonia by replacement 

 of hydrogen atoms by acid radicals. Thus : 



/H /C 2 H 3 /C 2 H 3 O 



N-H, N H N C 2 H 3 N H 2 . 



\H \H \H VH 2 



Ammonia. Acetamide. Diacetamide. Carbamide 



or urea. 



Amides also resemble ammonia in their chemical properties; 

 to a less extent, however, than amines, because the acid radicals 

 have a tendency to neutralize the basic properties of ammonia. 



