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VI. — On the Products of the Destructive Distillation of Animal Substances. 

 Part V. By Thomas Anderson, M.D., Professor of Chemistry in the 

 University of Glasgow. 



(Read 20th April 1868.— Sent for publication, November 1868). 



In the fourth part of these researches, I described a new base produced by 

 the action of sodium upon picoline, to which I gave the name of Parapicoline, 

 because it has the same composition as picoline, although the circumstances 

 of its formation appeared to show that it had been produced by the combination 

 of two molecules of that substance, so that its true formula would be C 12 H 14 N 2 . 

 Unfortunately, its high boiling point, and tendency to decompose when distilled, 

 made it impossible to determine its vapour density, which afforded the only 

 means of ascertaining whether this hypothesis was correct; and it was only 

 assumed, because similar cases of polymerisation had been established beyond 

 a doubt in the case of other classes of organic compounds. In the hope of 

 obtaining a similar base of lower boiling point, and therefore better adapted 

 to the necessary experiments, I have submitted pyridine to the action of sodium, 

 and the results of the inquiry are contained in the following pages. 



My earlier experiments were conducted in precisely the same manner as 

 those with picoline. Dry pyridine was heated to its boiling point along with 

 small pieces of sodium, amounting to about one-fifth of its weight, in a flask 

 furnished with a long cohobating tube. As the temperature rose, the pieces of 

 sodium became covered with a brown coating ; purple streaks appeared in the 

 fluid, which, however, soon disappeared again ; and after some hours the whole 

 fluid was converted into a dark-brown or black mass, which was viscous when hot, 

 and on cooling solidified into a hard brittle resin. In this a few white powdery 

 nodules are disseminated, which explode violently when brought in contact 

 with water. A large portion of the sodium employed remains unacted on, and if 

 the operation has been well performed, is generally found collected into one or 

 two large pieces, which can be easily separated from the resinous mass. After 

 the sodium has been removed as thoroughly as possible, the crude product is 

 thrown into water in small successive portions, so as to avoid the risk of explo- 

 sions from any particles of sodium which may have remained disseminated 

 through it. The water soon becomes alkaline, owing to the presence of caustic 

 soda; unchanged pyridine makes itself manifest by its powerful smell, and the 

 resin is slowly converted into a thick, viscid oil of dark-brown colour, and nearly, 

 or altogether, insoluble in water, which collects at the bottom of the vessel. This 

 oil is washed several times with water, dried over calcic-chloride, and distilled. 

 The distillation is best effected in a current of hydrogen, and at a temperature 



VOL. XXV. PART I. 3 G 



