STAINING, PRACTICAL AND THEORETICAL 



SUDAN BLACK B 



Michrome No. 165. Molecular weight 457. A neutral dis-azo 

 colouring matter. Solubility at 15° C; water nil, absolute alcohol 

 0-25%. 



-N=N 



N=N 



H 



I 

 ^\ 



I 

 H 



CH3 

 CH3 



SUDAN 2 



Michrome No. 153, Molecular weight 276. A neutral mono-azo 

 colouring matter. Solubility at 15° C; water nil, absolute alcohol 

 0-28%. 



HaC 



CHc 



OH 



N=N 



SUDAN 3 



Michrome No. 312. Molecular weight 352. A neutral dis-azo 

 colouring matter. Solubility at 15° C; water nil, absolute alcohol 



0-25%. 



OH 



N=N 



■N=N 



* 1% in neutral distilled water; see pages 17 and 29. 



52 



