2 7 1) Dr. W. Ramsay on Picoline and its Derivatives. 



There can be no doubt that these bodies are direct addition- 

 products ; for, besides the fact of their evolving picoline when 

 treated with potash, the bromine compound when heated de- 

 composes violently, and changes to a resin. This would not 

 have happened had the bromine acted on picoline hydrobro- 

 mide and not on picoline. 



Such, then, are the results of the action of the halogens on 

 picoline. They appear to form four distinct products : — (1) a 

 direct addition compound containing picoline plus two atoms 

 of halogen ; (2) a substitution compound which undergoes 

 alteration when brought into contact with water ; (3) a salt of 

 the halogen acid ; and (4) an addition-product containing two 

 atoms of the halogen combined with the haloid salt. Most 

 probably, when chlorine or bromine acts on picoline, all four 

 are formed, besides a resin resulting from some deeper action. 

 If the resin be warmed in an atmosphere of chlorine, it becomes 

 lighter in colour, refuses to dissolve in water, and smells 

 strongly of chlorine ; I have not, however, examined the 

 product. 



I shall now describe a few of the salts of picoline which have 

 not previously been prepared. 



• Ferrocyanide. — Picoline, treated with an aqueous solution 

 of hydroferrocyanic acid, deposited after some weeks crystals 

 of a compound which was probably the ferrocyanide ; but a 

 large amount of a blue precipitate was also formed. 



Platinocyanide. — This beautiful salt was prepared by treat- 

 ing picoline with the calculated amount of hydroplatinocyanic 

 acid, and evaporating the solution over sulphuric acid. It 

 crystallizes in pale yellow transparent crystals, apparently 

 rhomboidal. It was analyzed with the following result : — 



0-5028 at 120° lost 0*0628 = 12*50 per cent, H 2 O, and on 

 ignition gave 0*1770 grm. of Pt = 35*20 per cent. 



Calculated for Pt (C2\ T ) 2 2 HON . 2 C 6 H 7 N . +4 H 2 O, 



H 2 = 12*83 per cent,, Pt=35*ll per cent. 



On recrystallization from a hot solution, needles were de- 

 posited which appear to contain a different amount of water 

 of crystallization ; the platinum found (34*3 per cent.) cor- 

 responds to a salt containing 5 H 2 0, which demands 34*02 per 

 cent, of Pt, 



1 part of picoline platinocyanide dissolves in 83 parts of 

 water at 10°. 



Tartrate. — Two molecules of picoline were mixed with one 

 molecule of tartaric acid, and the solution was allowed to 

 evaporate over sulphuric acid ; after a week, long white 

 needles were formed, which smelled faintly of picoline. They 



