36 THE BUTYRIC ACID GROUP. 



tion with amide completely lose their basicity. The knowledge of 

 these amide-compounds, and of their general characters, which have 

 only recently attracted the attention of chemists, is of great 

 importance, because there is reason for believing that several 

 substances occurring in the animal and vegetable kingdoms belong 

 to this class of bodies. 



While the amides of many other acids can be artificially 

 produced, by the exposure of the ammonia-salt to heat, or by the 

 treatment of the chlorine-compounds w r ith ammonia, the amides 

 of the acids of this group are best obtained from their salts of oxide 

 of ethyl and ammonia. Thus acetamide is formed on digesting 

 acetate of oxide of ethyl (acetic ether) with fluid ammonia, since 



As is shown in this formula, the oxide of ethyl becomes con- 

 verted in this process into the hydrated oxide, or, in other words, 

 the ether becomes converted into alcohol ; the water necessary for 

 this change is formed from 1 atom of the oxygen of the acetic acid 

 and 1 atom of the hydrogen of the ammonia. 



The amides of these acids are solid, crystallisable, and colour- 

 less ; they are soluble in water and alcohol, sublime without 

 undergoing decomposition, have no action on vegetable colours, 

 and are indifferent towards weak acids and bases. If, however, 

 they be treated with strong acids or bases, they assimilate water 

 and become decomposed into ammonia and the corresponding 

 acid. 



Acetamide, treated with caustic potash, yields ammonia and 

 acetate of potash : C 4 H 5 NO 2 + KO.HO^ KO. C 4 H 3 O 3 + H 3 N. 



The behaviour of this amide, as well as that of all others, 

 towards nitrous acid, is very characteristic ; for, by the action of 

 this acid, these amides are converted into the original acids, 

 ammonia being at the same time developed. (Piria.*) 



We may explain this process by supposing that hydrogen is 

 assimilated through the action of the nitrous acid on the amide, and 

 that ammonia and the organic acid are formed, the ammonia,however, 

 in statu nascenti, becoming decomposed with the nitrous acid into 

 water and nitrogen ; thus, for instance_, acetamide and nitrous acid 

 yield water, acetic acid, and nitrogen, for C 4 H 5 NO 2 + NO 3 = 

 C 4 H 3 O 3 + 2 HO + 2 N. In this way we may hope that several 

 nitrogenous animal matters may be discovered to be amides, as in 

 the case of asparagin, which has been shown to be the amide of 

 malic acid. 



* Ann. de Chim. et de Phys. 3 Ser, t. 22, pp. 170-179. 



