1 835.] of the Distillation of Pit Coal , 51 



Separation of Cyanol and Leucol. 



Mix together and agitate 12 parts of coal oil, 2 of lime 

 arid 50 of water. After 6 or 8 hours pass the liquid through 

 a filter. It is of a brownish yellow colour and should be 

 distilled to one half. The liquid which comes over con- 

 sists of a thick oil, and a solution of it in water contains 

 carbolic acid in combination with ammonia, leucol, pyrrol, 

 and cyanol. Five distillations are required to separate the 

 cyanol and leucol from this mixture. The first distillation 

 is conducted with an excess of muriatic acid, by which 

 means the pyrrol and carbolic acid pass over into the receiver, 

 and the process is continued till the liquid passing over is no 

 longer red, brown, or yellow, when it is to be mixed with nitric 

 acid. The retort now contains a mixture of ammonia, leucol 

 and cyanol in union with nitric acid. This mixture possesses 

 a bright lyellow colour, and should now be distilled with an 

 excess of caustic soda. The three bases pass over into the 

 receiver with the water, and in the retort remains the yellow 

 ley with nitric acid. The matter is to be re-distilled with 

 an excess of acetic acid, and the process is to be continued till 

 the liquid passing over tinges fir wood. Acetate of cyanol 

 and leucol collect in the form of a colourless solution in the 

 receiver, while a great portion of the ammonia remains in 

 combination with acetic acid forming a residuum. 



The acetic acid salts are now to be converted into oxalates 

 by distillation with oxalic acid. When the liquid which 

 passes over tinges wood yellow, it is a proof that the bases 

 are saturated. The liquid in the receiver is now to be gently 

 evaporated to dryness. The mass consisting of oxalates of 

 cyanol and leucol mixed with a little colouring matter 

 and ammonia, should be reduced to powder digested with 

 spirits, and thrown on a filter. The spirits and colouring 

 matter pass through the filter and leave the salts. This 

 digestion and filtration should be repeated until the liquid 

 passing through is colourless. The funnel should then be 

 transferred to another vessel, and spirits digested on the 

 salts as long as any are dissolved. 



Oxalate of ammonia now remains upon the filter, and 

 the spirits contain in solution oxalates of cyanol and leucol, 

 which by the evaporation of the spirits are obtained in crys - 

 tals. These are to be dissolved in water and laid aside 



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