Colour and Chemical Constitution. 
235 
(b) 3-6-dioxyphenolphthalein, from Thiele's dioxy-acid, gives a large 
difference between caustic and bicarbonate colour, viz. A 549 and A 563 
respectively . 
(c) 4-5-dioxyphenolphthalein, from normetahemipinic acid, gives a 
similar difference, viz. A 558 in NaOH, and A 568 in NaHC0 3 . 
(d) 5-methoxyphenolphthalein, from 4-methoxyphthalic acid, has 
A 565. 
(e) 3-6-dimethoxyphenolphthalein has A 568. 
(/) 4-5-dimethoxyphenolphthalein (" phenolmetahemipineine ") has 
A 556. 
(g) 5-6-dimethoxyphenolphthalein (" phenolhemipineine ") has A 571. 
I have to thank the Institute of Chemistry for obtaining for me small 
quantities of the necessary acids from unknown donors in the English 
universities. 
(h) 3-nitrophenolphthalein, from 3-nitrophthalic acid, has A 570. The 
value A 559 was given in 1918, and is erroneous. 
(i) a-nitro-fgjk-tetrabromophenolphthalein has A 597 (blue-violet). 
(See Part XI, p. 130, for the nomenclature.) 
(j) 5-nitrophenolphthalein, from 4-nitrophthalic acid, has A 572. Its 
tetrabromo-compound has A 599. 
(k) 3-4-5-6- (or abcd)-tetrachlorophenolphthalein (" phenoltetrachloro- 
phthalein ") has A 581, scarcely different from that of the common (fgjk) 
isomer, viz. A 583. 
(I) Phenoldimethylalphanaphthylaminephthalein is green, A 625. 
C. Derivatives of Ghosh's Quinolinic Acid. 
These are phthaleins with N for CH in the phthalic ring. 
I. Phenolquinolineine has A 533. 
II. Orthocresolquinolineine has A 544. 
III. Thymolquinolineine has A 593. 
IV. Eesorcinquinolineine has A 490. 
V. Orcinquinolineine has A 496. 
D. Derivatives of Triphenylcarbinol. 
1. Ortho-oxy-malachite green (salicyl-green) has A 627 in neutral solu- 
tion, A 572 in alkali, and A 505 in acid. 
2. 2 / -oxy-4-dimethylaminofuchsone (foregoing with OH for NMe 2 ) has 
A 490 neutral, A 533 in alkali, and A 479 in acid. 
3. ^-methoxy-malachite green, from anisaldehyd, has only one colour, 
viz. A 605. 
