164 



Prof. J. Dewar. 



[Feb. 12, 



February 12, 1880. 



THE PRESIDENT in the Chair. 



The Presents received were laid on the table, and thanks ordered for 

 them. 



The following Papers were read : — 



I. " Studies on the Chinoline Series." By James Dewar, M.A., 

 F.R.S., Jacksonian Professor, University of Cambridge. 

 Received February 10, 1880. 



In the first part of this paper which appeared in the " Proceedings " 

 of the Society for 1877, it was shown that the leucoline series of bases 

 occurring in coal tar were really aromatic derivatives, as on oxidation 

 an acid could be obtained which readily decomposed on distilling with 

 an alkali, giving aniline. 



The acid, which was named leucolinic acid, had the composition 

 C 9 H 9 KOo, and may be regarded as a higher homologue of isatic acid, 

 C 8 H 7 NOo, which is one of the characteristic indigo derivatives. The 

 conclusions of this paper have been confirmed by the synthesis of 

 chinoline by Baeyer from the hydro-carbostyril, and by Koenigs 

 from allylaniline, the latter reaction being similar in principle to the 

 synthesis of pyrrol, described in my former paper, by passing ammonia 

 and a mixture of monobromethylene and acetylene through a red hot 

 tube. 



Experiments on the oxidation of leucoline and the alkaloidal bases 

 have been repeated by Hoogewerff, Van Dorp, and Koenigs. These 

 experimenters have found that instead of leucolinic acid being pro- 

 duced, they obtain a variety of pyridene dicarbonic acid, a substance 

 which I had on a former occasion separated from the oxidation pro- 

 ducts of picoline. 



The explanation of the difference of the results is to be found in 

 the fact, that my object was to obtain the first products of oxidation 

 and thus to avoid breaking up the body into simpler constituents. 



Both the tar and cinchona bases may be regarded as having a 

 double nucleus of a benzol and pyridene residue, and the latter, being 

 the more stable of the two, derivatives of it are obtained when the 

 oxidation is more complete. 



