SECTION ONE 



CHLORAZOL SKY BLUE FF 



Michrome No. 91. Molecular weight 993. An acid dis-azo dye, 

 pH 8-4*. Solubility at 15° C : water 4 "75%, absolute alcohol, nil. 



OCH3 



N=N 



-N=N 



OCH3 



OH NH2 



SOgNa 



SOsNa 

 OHNH2 



SOsNa 



SOaNa 



CHROMOTROPE 2R 



Michrome No. 301. Molecular weight 468. An acid mono-azo 

 dye, pHy-S*. Solubility at 15° C; water 19%, absolute alcohol 



o-iS%- 



OH OH 



-N=N 

 NaOaS 



I— SOgNa 



CHRYSOIDIN Y 



Michrome No. 96. Molecular weight 249. A basic motio-azo dye, 

 pH 3 -65*. Solubility at 15° C: water 5 -5%, absolute alcohol ^-j^yQ. 



NH2 



/~\— N=N-^^~\— NH2, HCl 



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



47 



