( 377 ) 



XXVI. — Researches on Chinoline and its Homologues. By C. Greville Williams, 

 Assistant to Dr Anderson, University of Glasgow. 



(Read 7th April 1856.) 



Twenty-two years have now elapsed, since Runge first published his remark, 

 able experiments on coal naphtha,* and it would, perhaps, be difficult to instance 

 any chemical investigation which has formed the point of departure of a greater 

 number of researches. When we consider the vast quantity of bodies which have, 

 first and last, been obtained from coal-tar, it might appear that little more 

 remained to be done, — that the mine was exhausted, — but so far from this being 

 the case, the discovery of one substance has only served to pave the way for the 

 isolation of others. 



Among the bodies examined by Runge, there was one which apparently pos- 

 sessed comparatively few features of interest ; indeed its very name (the first syl- 

 lable derived from xeuxog) was intended to express its supposed inability to produce 

 coloured reactions, a feature which, in the chemistry of the time, militated greatly 

 against its claims to notice. I have used the expression " supposed inability," be- 

 cause I shall show further on, that this substance is capable, under certain condi- 

 tions, of affording extremely brilliant colorations. Eventually, Gerhardt,! by 

 acting on quinine, cinchonine, and strychnine, with hydrate of potash, obtained the 

 same body. The first chemist who succeeded in procuring any of its compounds in 

 a state of tolerable purity was Hofmann, whose analysis of the platinum salt is 

 very nearly exact. But, at the time of that analysis, he was of opinion that the 

 products obtained from coal and chinoline were essentially different, an opinion 

 which he subsequently retracted. In the mean time, the alkaloid, as obtained 

 from cinchonine was examined by BromeisJ and Laurent, § their results, how- 

 ever, not elucidating the composition of the basic fluid obtained in the manner 

 alluded to. 



Some time since, I undertook the examination of the bases produced by de- 

 structive distillation of the bituminous shale of Dorsetshire, and found them to 

 be identical with those from bone-oil. || I now began to see the great probability 

 that all processes of destructive distillation of nitrogenous matter at very elevated 



* Poggend. Annal., Bd. xxxi., p. 65 und 513; und Bd. xxxii., p. 308 und 328. 



■f Kevue Scientif., x., 186. Compt. Bend, des Trav. de Chirn. 1845, p. 30. 



J Liebig's Annal., Bd. lii., p. 130 ; and Ann. der Chem. u. Pharm. lii., 130. 



§ Ann. de China, et de Phys. [3] xxx., 368. 



I Quart. Jour. Chern. Soc. Lond., July 1854. 



VOL. XXI. PART III. 5 K 



