378 MR C. G. WILLIAMS' RESEARCHES ON 



temperatures would result in the formation of the same classes of alkaloids, and 

 subsequent researches* have only tended to confirm this view. In a little paper, 

 " On some of the basic constituents of Coal-Naphtha, and on Chrysene,"! I have 

 given a table, showing the extraordinary similarity of the basic products derived 

 by dry distillation from Dippel's oil, coal, the Dorset shale, and cinchonine. The 

 last of these researches was undertaken in the endeavour to throw light upon the 

 discrepancies in the results of the chemists who had previously examined chino- 

 line, the experiments being embodied in a paper which appeared in the Transac- 

 tions of the Society last year. In that communication, $ I showed that the fluid 

 usually known as chinoline, and supposed to have the formula C 1S H. N, had, in 

 fact, a very complex constitution, and contained in addition to that base, six 

 others. As my chief object at that time, was to demonstrate the real nature of 

 the decomposition which cinchonine undergoes at an elevated temperature in the 

 presence of alkalies, I did not make a minute examination of the chinoline itself, 

 as I conceived it to be sufficient for the purposes of that investigation to show 

 that a base of the formula C l8 H 7 N did really exist in the fluid. This fact was 

 by no means a matter of course, for the analyses of the chinoline from cinchonine 

 previously published were so conflicting, that it was a difficult matter to derive a 

 formula from them. Hofmann's analyses were made upon a product from coal- 

 tar, and the formula he gave as the expression of his results, was C ls H g N. But 

 as an even number of atoms of hydrogen in a body containing an equivalent of 

 nitrogen, was incompatible with views now almost universally received of the 

 constitution of organic bodies, C 18 H 7 N was taken by most chemists as the true 

 formula of the base from coal-tar. But the wide differences in the analyses of 

 the chinoline obtained by distilling cinchonine with potash, induced Gerhaedt § 

 to express doubts, as to whether C 18 H 7 N, or C 20 H N was the correct formula, 

 although he appears to lean towards the latter, for he places it at the head of the 

 section, but, nevertheless, shows that the formula is open to doubt, by annexing 

 a note of interrogation to it. I have shown the cause of the variable nature of 

 the results obtained by other experimenters, and have proved the existence of a 

 homologous series, of which, until I commenced this investigation, only one mem- 

 ber was known. 



Many circumstances conspire to render a detailed examination of chinoline a 

 problem of interest, for, perhaps, no other body, known for an equal length of time, 

 and investigated by so many hands, is so erroneously described in the manuals 

 of organic chemistry. In fact, there are few things stated regarding it, that are 

 not more or less incorrect. 



* I take this opportunity of expressing my sense of Dr Anderson's kindness, in permitting me 

 to make use of his laboratory and apparatus, during my endeavours to realize this idea. 

 f Chem. Gazette, Nov. 1, 1855; and Edin. Phil. Jour., Oct. 1855. 

 + Trans. Roy. Soc. Edin., vol. xxi., part ii. 

 § Traite de Chimie Organique, troisieme partie, p. 148. 



