66 
Transactions of the Royal Society of South Africa. 
If two of the linkages are present in a phenolic dye, the figure 1380 is to 
be muliplied by both factors. 
I have also discovered that the effect of oxidising the linkage is always 
the same whatever the linkage is. The effect is to make the factor of the 
oxidised linkage exactly f of the factor of the unoxidised linkage.* This 
may be due, as explained in Part XII, to changing from five tautomerisms 
to three only. 
Table of Factors for Oxidised Linkages. 
E. Oxymethylene or carbinol linkage, /CHOHx^ Value 0 39 
F. Dioxymethylene or keto linkage, / CO \^ Value 0*234 
<3r. Oximino or hvdroxylamine linkage, / NOH \^ Value 0 47 
O 
H. Peroxide linkage, / 0 \ • • • • Value 0*535 
I. Sulphoxide linkage, / SO\ . . . . Value 0 55 
J. Sulphone linkage, /SO a \ .... Value 0 33 (?) 
[K. Trebly-linked carbinol, = COH . . . Value 0*386] 
These are all the new data required for the calculations, but in addition 
all of the 27 ring-colour-factors published in Part X may be used so as to 
extend the theory from the phenolic dyes to all sorts of classes of dicyclic 
dyes. Thus, for bis-dimethylamino dyes the figure for the corresponding 
phenolic dye is to be multiplied by the square of 1 059, the factor for 
replacement of OH by NMe 3 (Part X, p. 306, middle), or alternatively, 
instead of A 1380, use A 1380 x (1 059) 2 = A 1548 for the fundamental 
vibration round two dimethylaniline rings. Similarly the fundamental 
vibration for two aniline rings is A 1380 x [k^^j or A 1400 (Part X, 
p. 304). 
According to this theory the colour of the majority of the singly-linked 
dicyclic substances, such as dioxydiphenylmethane, is in the infra-red : those 
which are observable to the eye are calculated below. 
(1) Dioxybenzhydrol (formula on p. 65). — The calculated A is 1380 x 
factor E = 1380 x 0 39 = A 538. Observed A 539. 
(2) Benzaurine (di-para- variety). — This is the C-phenyl derivative of the 
foregoing. The C-phenyl factor is 1 026 (Part X, p. 310). Calculated A 
= 1380 x 0*39 x 1*026 = A 552. Observed A 553. 
(3) Michlers hydrol. — This is two dimethylaniline rings joined by 
CHOH. Calculated A = 1548 x 0 39 = A 604. Observed A 603. 
(4) Malachite green. — This is the C-phenyl derivative of No. 3. Calculated 
A = 1548 x 0 39 x 1*026 = A 620. Observed A 619. 
* Watson and Meek first showed this to be the case for the CO group. 
