Colour and Chemical Constitution. 
277 
Monocyclic Dimethylamino-compounds. 
NMe 2 HA . 
The multiplying factor for ^ is 1-25, i.e. for acid solutions. For 
the neutral phases the factor is 1-13, i.e. the bands of a neutral dimethylamino 
substance are practically the same as those of the corresponding oxy sub- 
stance examined in acid solution (see previous page). 
Table of Calculated Dimethylamino-compounds (Acid). 
Name. 
Calculated A. 
Observed X. 
Dimethyl -p-toluidine 
330 
jD-dimethylaminobenzaldehyde . 
399 
About 380 and 355. 
Dimethylaminobenzophenone 
452 
Probably exceptional. 
Dimethylaminobenzhydrol 
411 
About 405. 
Dimethylaminobenzyl alcohol 
363 
Dimethylfuchsonium salts . 
466 
460. 
Dimethylaminotriphenylmethane 
425 
Dimethyl -^-phenylenediamine 
392 
Dimethyl-quinonediimine . 
429 
About 400. 
Dimethylaminodiphenylamine 
445 
Dimethylphenylquinonediimine . 
488 
Nitrosodimethylaniline 
474 
457. 
Butter-yeilow A 
542 
543. 
B 
509 
508. 
Dimethylaminobenzalaniline A . 
508 
513. 
B . 
480 
482. 
Benzaldimethylphenylenediamine A 
455 
460. 
B 
430 
427. 
Dimethylaminostilbene A . 
430 
B . 
403 
375. 
Dimethylaminoazoxybenzene 
559 
Dimethylamino -stilbeneoxide 
445 
Dimethylamino -benzophenoneanile 
524 
There are still many blanks in the observations, it being almost impos- 
sible for one investigator to repeat all the work which has stretched over 
the last thirty-five years ; but the calculations cover nearly all the possible 
monocyclic compounds of this class. 
Quinone Compounds. — Quinone in water has a band at A 455 or 460 
(centre vague), but cannot be observed in alkaline solution, i.e. as 
HO . O . C 6 H 4 : O' on account of oxidation. Assuming, however, that 
the water solution is ionised, we calculate the a- oxo-inter position factor to 
be about 457-^315 J (quinol) or 1-45. 
Quinonedioxime (in excess NaOH, as it is a very weak acid) has a sharp, 
strong band at A 366, and quinonemonoxime in alkali a band which is 
21 
