Nitro and Azo Dyes 75 



Lillie (1940) suggests this dye (under the name Azofuchsin 3B) 

 among possible substitutes for "ponceau de xyhdene" in the 

 Masson trichrome technic. 



AZO FUCHSIN 



There is an occasional reference in histology to the use of an 

 azo fuchsin. Such references are not sufficiently definite, how- 

 ever, as there are several different azo fuchsins. The following, 

 for example, are recognized in the Colour Index: 



All of these acid mono-azo dyes are closely related chemically 

 to orange G and Bordeaux red. 



Of these, Lillie (1948) definitely specifies C. I. No. 153 as a con- 

 stituent of his naphthol blue black tissue stain. 



c25 AZO ACID BLUE B C. I. NO. 59 



There are various azo acid blues, with various shade designa- 

 tions attached to the names, but whose synonymy is somewhat 

 confusing.' They are mixtures; but an important constituent is 

 regarded as being 



NaSOj 

 CisHisNaOoSXa; MoL Wt. 409.389 



{An acid dye) 



Menner (1935) has called for this dye in a stain for nervous 

 tissue. Otherwise there seem to be few, if any, references to it in 

 the biological literature. 



