196 MR JAMES DEWAR ON THE OXIDATION PRODUCTS OF PICOLINE. 



between pyrrol and true nitrile bases, they being simultaneously produced in 

 the majority of reactions, would lead us to expect a like class of derivatives 

 being obtainable from pyridine. 



Hubner (Ann. Chem. u. Pharm., vol. 141) has described the oxidation 

 products of nicotine, got by the action of sulphuric acid and bichromate of 

 potassium. In that memoir he describes an acid so obtained, having the 

 formula C 5 H 5 N0 2 . This acid is identical in composition with mono-carbopyri- 

 denic acid. The base nicotine itself differs from dipyridine by only four hydro- 

 Nicotine. Dipyridine. 

 C 5 H 7 N C 5 H 5 N 

 C 5 H 7 N C 5 H 5 N 



gens ; and as the nucleus of nicotine is a nitrile nucleus, it is not at all impro- 

 bable that this acid may be a member of the series to which dicarbopyridenic 

 belongs, so that nicotine may be similarly constituted to Anderson's poly- 

 merised bases. 



The stability of these bases to the majority of reagents (especially the 

 primary member of the group, pyridine) would predispose us to look upon it as 

 analogous to benzol, and to suppose that the atoms are symmetrically grouped. 

 The syntheses of Baeyer support this view, and there is not any reason why 

 we may not have as many stable derivatives from this nucleus as from benzol. I 

 have already pointed out the analogy between the chinoline series and the 

 pyridine series ; and in a short time I hope to be able to publish details support- 

 ing the theoretical relations above given. 



In the meantime, the following analogies may be pointed out between 

 benzol- and nitrile-clerivatives ; thus — 



Benzol. 



Naphthaline. 



Anthracine. 



Pyridine. 



Chinoline. 



C 2 H 2 



C 6 H 4 



C 6 H 4 



C 2 H 2 



C 5 H 3 N 



C 2 H 2 



C 2 H 2 



C 2 H 2 



NCH 



C 2 H 2 



C 2 H 2 



C 2 H 2 



C 6 H 4 



C 2 H 2 



C 2 H 2 



Indol, from its general characteristics, evidently belongs to the pyrrol series, 

 the following showing, in all probability, the relative structure of indol and 

 pyrrol : — 



Indol. 



Pyrrol. 



C 6 H 4 



C 2 H 2 



NH 



NH 



C 2 H 2 



C 2 H 2 



According to this hypothesis indol is simply benzol-pyrrol. 



