166 Biological Stains 



amino groups. Some of them are acid and some basic dyes. 

 There is occasional reference in the biological literature to the use 

 of a benzyl violet, but without any indication as to which of the 

 dyes in question is intended. 



n50 



SPIRIT BLUE C. I. NO. 689 



Synonyms: Geniiana blue 6B. Anilin blue, alcohol sohible. 

 Light blue. Lyon blue. Paris blue. 



This is a mixture of di-phenyl rosanilin chloride: 



H 



I 

 N /-\ 



CI 



H \/— \ NHj 



CH3 



C32H28N3CI; Mol. Wt. 490.025- 



and tri-phenyl pararosanilin chloride: 



CI 



I 



I \_/ 

 H \/-\ N_/-\ 



"I \_/ 

 H 



C37H30N3CI; Mol Wi. 552.091 



{Basic dyes absorption maximum of spirit blue 2R 

 about 581 in alcohol.) 



Solubility at 26° C: in water nil; in alcohol 1.10% 



Lynch (1930) mentioned Lyons blue (undoubtedly this dye) as a 

 satisfactory counterstain to carmine in bulk staining of protozoa 

 and other small animals and embryos. It has, moreover, been re-, 

 ported by others as a good contrast stain for carmine, bringing 

 out nerve fibers well in embryonic tissue; for this purpose it is 

 used in strong alcoholic solution. Quite recently, Knaysi (1942) 

 has mentioned this dye as one whose color base can be used in de- 

 termining hydrolysis of fats. 



