SECTION ONE 



CHLORAZOL AZURINE 



Michrome No. 729. Molecular weight 759. An acid dis-azo dye, 

 pH g-^*. Solubility at 15° C: water 1-5%, absolute alcohol o-i%. 



OCH3 



OH 



N=N— I 



N=N 



OCH3 



SOaNa 



OH 



NaOsS 



CHLORAZOL BLACK E 



Michrome No. 92. Molecular weight 782. An acid tris-azo dye, 

 pH g'O^*. Solubility at 15° C: water 6%, absolute alcohol o-i%. 



NH2OH 



NaOsS 



N=N 

 SOsNa 



NH2 



■N=N 



NHs 



* ,0, 



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



45 



