36 
Transactions of the Royal Society of South Africa. 
Me 2 N /NMe 2 
\j o 
\ / 
CH(OH) 
I.-—Bis-dimethylaminobenzhydrol. " Michler's hydrol." 
Me 9 N NMe 2 
rv 
II. — Bis-dimethylamino-xanthhydrol. The dye pyronine. 
I have now found that the colours of the monocyclic dyes (which, by the 
way, are all low, viz. below X 500) can be calculated by a factorial scheme 
similar to that of Part X, but that the factors are all different from the 
corresponding factors of the dicyclic scheme. 
The parent substance is paraoxybenzylalcohol 
HO<^ ^CHoOH 
(oxyphenylcarbinol), which has a calculated X of 290 for faintly alkaline 
water solution. This substance is interesting since its anhydride is the 
hypothetical quinomethane, 
O :/ \ : CH,, 
which is the parent- substance of the common "aniline dyes" according to 
the upholders of the quinonoid theory of colour. 
The factors required for colour-calculations are : 
A. Phenyl-factor, for replacement of H in carbinol by Ph = 1135. 
B. Orthocarboxyl-factor, for conversion of a phenylcarbinol 
into a phthalein . . . . . . . = 1 '060. 
C. Phthalein-factor, or factor A x factor B, for replacing H 
byC 6 H 4 C0 2 H =1203. 
D. Aminocompound-factor, for replacing OH in ring by NH 2 = 1T40. 
E. N -methyl-factor, for replacing H in NH 3 by CH H . = 1 035. 
F. Methylaminocompound-factor, for replacing OH by 
NHMe = DxE = 1180. 
Gr. Dimethylaminocompound-factor, for replacing OH by 
NMe 0 = D x W = 122. 
