STAINING, PRACTICAL AND THEORETICAL 



TABLE V 



TRIPHENYLMETHANE DYES 



In selecting dyes, based on their molecular weights, in accord- 

 ance with the earlier hypothesis (E. Gurr, i960, pages 423-432, 

 and E. Gurr and M. A. MacConaill, 1959) regarding the influence 

 of the molecular weights of dyes on the kinds of tissue-elements 

 stained by them, consideration should be given not to weight of 

 the dye molecule as a whole but to the mass of the single dye- 

 ion. Dyes marked *tt (^^^ P^g^ 23) dissociate, in solution into 

 two or three separate univalent dye-ions, and it is the mass of 

 these single dye-ions, not the molecular weight of the dye- 

 molecule as a whole which has to be taken into consideration. 



26 



