Dr Anderson on the Proper He s of Picoline. 149 



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 pro- 

 pose the name of Picoline, and the examination of whose pro- 

 perties forms the subject of the present paper. 



Preparation of Picoline^ 



For the crude substance employed in the preparation of 

 picoline, I am indebted to the kindness of Mr Astley of the 

 Bonnington Chemical Works, and it was obtained by the fol- 

 lowing modification of Runge' s process. In the preparation 

 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 present, as well as a variety of 

 substances in extremely minute quantity, which communicate 

 to the crude naphtha the property of becoming dark-coloured 

 by exposure to the air ; among these substances, of course, 

 are all the basic compounds contained in the oil. The sul- 

 phuric acid which had been used for this purpose was neu- 

 tralised by impure ammonia obtained by a single distillation 

 of the watery fluid of the gas-works. On the addition of the 

 ammonia there was no separation of any oil in quantity ap- 

 preciable to the eye ; but upon distillation, the bases, which 

 had been dissolved in the fluid, passed over with the first 

 portions of the water, and collected in a separate layer in 

 the receiver. This oil, when it came into my hands, pos- 

 sessed a very dark brown colour, a somewhat viscid consist- 

 ence, and a peculiar pungent and disagreeable odour. It was 

 heavier than water, a layer of which, containing a small pro- 

 portion of oil in solution, floated on the surface. The exa- 

 mination of this oil proved it to consist, in addition to pico- 

 line, of a mixture of pyrrol, aniline, an oily base possessing 

 the general properties of leukol, and a thick heavy oil desti- 

 tute of basic properties. 



In order to separate picoline, the oil, along with the water 

 which floated on its surface, was introduced into a retort and 

 carefully distilled. At first, water, accompanied by a little 

 oil, passed over, and then an oil by itself, which dissolved 



