STAINING, PRACTICAL AND THEORETICAL 



NAPHTHOL BLUE BLACK 



Michrome No. 60. Molecular weight 617. An acid dis-azo dye, 

 pH S'Sjs*- Solubility at 15° C: water 2-5%, absolute alcohol 3%. 



NH2OH 



O2N 



NaOgS 



N=N 

 SOaNa 



ORANGE G 



Michrome No. 411. Molecular weight 452. An acid mono-azo 

 dye, ^//875*. Solubility at 15° C; water 8%, absolute alcohol 



0-22%. 



OH 



SOsNa 



PONCEAU 3R 



Michrome No. 210. Molecular weight 494. An acid mono-azo 

 dye, pH j-z"^. Solubility at 15° C; water 3%, absolute alcohol 



o-3%- 



CHj 



HO SOsNa 



H3C 



N=N 



CH3 



SOsNa 



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



50 



