148 Dr Anderson on the Properties of Picolinel 



such as coal, where we have to deal not merely with one 

 complex atom but with a congeries of several such, and where 

 the process is performed on the large scale, and under a 

 variety of perturbing influences. The distillation of coal is, 

 in factj attended by the formation of about twenty different 

 substances, the constitution and properties of which have 

 been examined with different degrees of accuracy, and which 

 present among them instances of almost every species of 

 chemical compound. The discovery of six of these substances 

 is due to Runge,* who published, about fourteen years ago, 

 a very interesting memoir containing an account of their 

 general properties. Of these substances, three are possessed 

 of acid properties, and three are bases, to the latter of which 

 he gave the names of Kyanol, Leukol, and Pyrrol, from the 

 peculiar colours developed by the action of certain reagents 

 on their salts. The two former of these substances were 

 afterwards submitted to a detailed examination and analysis 

 by Hoffman,t who arrived at the interesting result, that both 

 are identical with substances which had been independently 

 obtained by the decomposition of certain well known bodies ; 

 Kyanol possessing the constitution and properties of the Ani- 

 line of Fritsche, and the Benzidam of Zinin ; while Leukol is 

 identical with the substance described by Gerhardt under the 

 name of Chinoline, and which was obtained by him as a pro- 

 duct of the distillation of quinine, cinchonine, and strychnia, 

 with caustic potass. Hoffman failed, however, entirely in 

 obtaining any evidence of the presence of pyrrol in the sub- 

 stance which he examined, and leaves in doubt the existence 

 of such a compound. 



Having lately had occasion to examine a quantity of the 

 mixed bases contained in coal-tar, obtained by a method simi- 

 lar to that of Runge, but which, owing to a modification of 

 the process, contained all the more volatile bases formed 

 during the distillation of coal, I was led to try whether or 

 not pyrrol was to be found in it, and I found immediate evi- 

 dence of its existence, by the characteristic red colour which 



* Poggendorf 8 Annalen, Band 31, u. 32. 



t Annalftn der Chemie und Pharmacie, vol. xlvii. 



