THE BUTYRIC ACID GROUP, 37 



If the amides of these acids be treated with anhydrous phos- 

 phoric acid, they lose 2 atoms of water, and nitrogenous bodies rich 

 in oxygen remain, which contain the radical of the acid and have 



1 equiv. of nitrogen in place of the 3 atoms of oxygen. These bodies 

 have been named nitriles. Notwithstanding the similarity of their 

 composition with that of the volatile oxygenous alkaloids, they 

 possess no basic properties. 



Valeramide and phosphoric acid form hydrated phosphoric acid 

 and valeronitrile : C 10 H H NO 2 + PO 5 =PO 5 .2HO +C 10 H 9 N. 



The amides of this group are finally distinguished by a property 

 which is not common to the amides of most other acids ; when 

 treated with potassium they yield cyanide of potassium and a carbo- 

 hydrogen. Hence it seems probable that cyanogen exists pre-formed 

 in these amides, since, from their total want of basic properties, it 

 cannot be supposed that they contain a conjugated ammonia and 

 that 1 atom of oxygen can be replaced by amide. 



Taking this view, acetamide must be regarded as hydrocyanate 

 of wood-spirit, and metacetamide as hydrocyanate of alcohol, for 

 C 4 H 5 NO 2 = C 2 H 4 O 2 . HC 2 N,and C 6 H 7 NO 2 = C 4 H 6 O 2 . HC 2 N. 



The amides lead us at once to a further consideration of 

 the nitrites, which are equally important in reference to our 

 knowledge of the arrangement of atoms and the metamorphosis 

 of matter. 



These bodies are, in part, formed during the decomposition of 

 animal substances by oxidising agents; they may, however, be 

 obtained by treating the corresponding ammonia-salt or the amide 

 with anhydrous phosphoric acid. This mode of preparation is 

 especially applicable for the nitriles of this group of acids ; others 

 are prepared either by the mere exposure of the ammonia-salt to 

 heat, or by passing the vapour over heated caustic lime. 



The nitriles are oily, very volatile fluids, less soluble in water 

 than in alcohol and ether, and having a peculiar odour ; they can 

 be distilled without undergoing decomposition, have no action on 

 vegetable colours, and do not unite with acids to form salts. They 

 unite, however, directly with sulphuretted hydrogen, assimilating 



2 equivalents of it, so that sulphurous substances analogous to the 

 amides are produced ; thus, for instance, benzonitrile, with sul- 

 phuretted hydrogen, forms sulphobenzamide, which is analogous 

 to benzamide: C 14 H 5 N + 2HS==C 14 H 7 NS 2 coC 14 H 7 NO 2 . 



Alkalies and strong acids reduce most of the nitriles to their 

 original component parts, that is to say, to ammonia and the cor- 



