SECTION ONE 



CRESYL FAST VIOLET CNS 



Michrome No. 530. Molecular weight 340. A basic dye, pH y-o*. 

 Solubility at 15° C: water 9*5%, absolute alcohol 6%. 



(H3C)2N 

 H3C— ' 



NH2 



ci- 



LACMOID 



Michrome No. 462. Molecular weight 235. A71 acid dye, 

 pH 7-85.* Solubility at 15° C: water 10%, absolute alcohol 10%. 



ONa 



NILE BLUE SULPHATEf 



Michrome No. 212. Molecular weight 733. A basic dye, 

 pH 5-15*. Solubility at 15° C; water 6%, absolute alcohol 5%. 



(C2H5)2N 



S04— 



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



t Note: Nile blue sulphate has the highest molecular weight of any basic dye 

 used in microscopy. This is due to the fact that its molecule is composed of 

 two univalent dye-ions attached to one divalent sulphate group, as their anion. 

 Such a dye in solution would split into two separate dye-ions each capable 

 separately of associating with univalent dye-ions to form a dye of approximately 

 half the molecular weight of the original dye (Gurr, i960, pp. 423-432). 



n* 61 



