1864.] 



derived from Coal-tar. 



491 



may possibly contain the bivalent radicals phenyleney Cg H^, and tolylene^ 

 He* 



(C,„HJ"=(C,HJ', 



when the molecular construction of the three colouring matters might be 

 represented by the formulae 



Aniline-red. Aniline-blue. Aniline-violet. 



(C.HJ" 1 (C.H.y l (C3HJ" 



(C, H,)," \ N„ H3 O (C, H,X" \ N3, H, O (C, H,X" \ N3, H, O. 

 H3 J (C.H,)3 J (C,H,)3 J 



We must not, however, forget that this is simply an hypothesis, and that 

 the elements in the complex atom C^q H^g may be associated in a great 

 variety of other groups. An interesting observation quite recently made 

 by Dr. Hugo Miiller, and communicated to me by my friend while these 

 pages are passing through the press, may possibly assist in further eluci- 

 dating the nature of this class of bodies. Dr. Miiller has found that 

 rosaniline and its coloured derivatives are instantaneously decolorized by 

 cyanide of potassium, a series of splendidly crystaUized, perfectly colourless 

 bases being produced. The composition of these bodies, which will pro- 

 bably be found analogous to a substance similarly obtained from harmaline 

 by Fritzsche, remains to be established. 



