124 DR ANDERSON ON THE CONSTITUTION AND PROPERTIES OF PICOLINE, 



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 com- 

 pound. The discovery of six of these substances is due to Runge,* who pub- 

 lished, about fourteen years ago, a very interesting memoir, containing an account 

 of their general properties. Of these substances, three are possessed of acid pro- 

 perties, 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 sub- 

 mitted to a detailed examination and analysis by Hoffman,! who arrived at the 

 interesting result, that both are identical with substances which had been inde- 

 pendently obtained by the decomposition of certain well known bodies ; Kyanol 

 possessing the constitution and properties of the Aniline of Feitsciie, 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 hira as a pro- 

 duct of the distillation of quinine, cinchonine, and strychnia, with caustic potass. 

 HoFFiLiN failed, however, entirely in obtaining any evidence of the presence of 

 pyrrol in the substance 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 con- 

 tained in coal-tar, obtained by a method similar to that of Runge, but which, 

 owing to a modification of the process, contained aU 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 obtained immediate evidence of its existence, by the character- 

 istic red colour which it gives to fir-wood moistened with hydrochloric acid. The 

 attempt to separate this pyrrol proved that it was present in extremely minute 

 quantity only, but led to the discovery of a new base different from those of 

 Runge, for which I propose the name of Picoline, and the examination of whose 

 properties forms the subject of the present paper. 



Preparation of Picoline. 



For the crude substance employed in the preparation of picoline, I am in- 

 debted to the kindness of Mr Astley, of the Bonnington Chemical Works, and it 

 was obtained by the following modification of Runge's process. In the prepara- 

 tion of naphtha from coal-tar, the first product of distillation is agitated with 

 sulphuric acid for the purpose of separating any naphthaline which may be pre- 

 sent, as well as a variety of substances in extremely minute quantity, which 

 communicate to the crude naphtha the property of becoming dark-coloured 



* Poggendorf's Annalen, Band 31, u. 32. 



\ Annalen der Chemie und Pharmacie, vol. xlvii.. 



