ACTION OF SULPHURIC ACID UPON THE AMIDES AND NITRILES. 469 
Butyl-Series. 
Our experiments in this series have been entirely qualitative. We have been satis- 
fied to establish experimentally the analogy of the reactions. These reactions, how- 
ever, become less and less definite, and, owing to tbe still greater solubility of the 
new products, their separation is attended with difficulties almost insurmountable. 
The researches detailed in the preceding pages are quite sufficient to establish the 
general character of the action of sulphuric acid upon the amides and nitriles. Never- 
theless, since these experiments exclusively refer to the derivatives of several homolo- 
gous terms of the series of fatty acids, it appeared desirable to extend the investiga- 
tion to a nitrile of the analogous group of aromatic acids. No substance appeared to 
be more appropriate for such an examination than benzonitrile, or cyanide of phenyl. 
Phenyl-Series, 
Preparation of Benzonitrile. 
M. Fehling originally obtained benzonitrile by subjecting benzoate of ammonium 
to repeated dry distillations, when the four equivalents of water gradually separated. 
The process is however objectionable, on account of the necessity of repeatedly 
returning by hand the sublimed salt to the volatilizing vessel. We hoped to have 
found a more convenient method, in submitting the same salt to the dehydrating 
action of chloride of zinc ; but on rectifying the distillate, we obtained only one- 
third of the product in the form of benzonitrile, the remaining portion being benzole. 
The safest, but somewhat lengthened, process for procuring benzonitrile, consists in 
dehydrating benzamide with anhydrous phosphoric acid, the former body having 
been produced by the action of carbonate of ammonium upon chloride of benzoyl, as 
recommended by M. Gerhardt. 
Action of Sulphuric Acid upon Benzonitrile. 
Sulphuric acid and benzonitrile mix with liberation of far less heat than is 
observable in the cases previously recounted. No gas is disengaged until the tem- 
perature is very considerably raised, when a portion of benzoic acid sublimes in the 
neck of the retort and carbon is deposited, while sulphurous acid is simultaneously 
disengaged. The action was continued for some time after the appearance of sul- 
phurous acid, for the purpose of decomposing the sulphobenzoic acid which analogy 
would lead us to expect among the products of the reaction. On cooling, a semi- 
transparent hard mass of glassy fracture remained in the retort. The usual treat- 
ment with carbonate of barium evolved ammonia, showing the presence of a salt of 
that base. 
3 Q 2 
