38 THE BUTYRIC ACID GROUP. 



responding acid, by assimilating 3 atoms of water ; thus, for instance, 

 in the case of valeronitrile : C 10 H 9 N + 3HO=:H 3 N + C 10 H 9 O 3 . 



Several of the properties of the nitriles, and especially the 

 modes in which they are decomposed, indicate that in their chemical 

 constitution they are not to be regarded as compounds of the radical 

 of the corresponding acid with nitrogen, but rather as combinations 

 of cyanogen and certain carbo-hydrogens ; a view which throws 

 a perfectly new light on the theoretical composition of the acids of 

 this group. 



If we first glance at the nitriles of the simplest acids of this 

 group, those of formic acid, acetic acid, and metacetonic acid, it 

 becomes manifest that these are bodies which have been long 

 known, but never have been, nor can be, regarded as nitriles. The 

 nitrile of formic acid must = C 2 HN; this, however, is the com- 

 position of hydrocyanic acid, which, as is well known, is also 

 obtained by heating formate of ammonia, three atoms of water 

 being separated. Hydrocyanic acid can, however, as we know, be 

 readily converted, like the nitriles, into ammonia and the corre- 

 sponding (formic) acid. 



If, farther, with the view of preparing the nitrile of acetic acid, 

 acetamide be mixed with anhydrous phosphoric acid, another long- 

 known body, supposed to be otherwise constituted,isformed,namely, 

 cyanide of methyl, for C 4 H 3 N=C 2 H 3 . C 3 N. The nitrile of meta- 

 cetonic acid which corresponds to cyanide of ethyl, behaves in 

 a perfectly similar manner, for C 6 H 5 Nr=C 4 H 5 .C 2 N. An intelli- 

 gent observer, Kolbe,* who has instituted very excellent observations 

 on the subject, struck upon the idea of preparing metacetonic 

 acid from the cyanide of ethyl, (obtained by the distillation of 

 sulphate of oxide of ethyl and potash, and cyanide of potassium), 

 by treating it with solution of potash ; and the attempt completely 

 succeeded, for the cyanide of ethyl (perfectly corresponding in its 

 nature to the aforesaid nitrile), took up 3 atoms of water, and became 

 decomposed into ammonia and metacetonic acid, according to the 

 formula, C 4 H 5 .C 2 N-f3HO=H 3 N-f C 6 H 5 O 3 . 



From these facts he was led to regard the nitriles (as far as they 

 are yet known) of the acids of this group as combinations of cyano- 

 gen with a radical of the haloid bases pertaining to the ether group, 

 that is to say, with a carbo-hydrogen in which there are contained a 

 large number of atoms of carbon, and the next higher odd number 



* Phil. Mag. Vol. 31, pp. 266-271. 



