804 Wisconsin Academy of Sciences, Arts, and Letters. 
the tubers. According to Rennie * 1 ) who has made a study of 
these pigments, each plant is provided with one tuber attached 
to a stem at a depth of 3 to 4 inches. The tubers vary from % 
to % of an inch in diameter. Each consists of an inner solid 
but soft nucleus, full of a reddish sap, and an outer series of 
thin, more or less dry, layers of an almost black material. Be¬ 
tween the layers is to be found, in small quantities, a brilliant 
red coloring matter, apparently most plentiful in the older 
tubers. The flowers of the species are white, resembling those 
of the white oxalis. The red pigment gives a violet, the orange 
red a deep red solution with ammonia and alkalies. 
This remarkable form of pigmentation is doubly interesting 
when considered from the view point of the quinhydrone hy¬ 
pothesis. Both of the substances are quinones, and both have 
in addition phenol groups. The presence of the corresponding 
hydroquinones has not been indicated, though both substances 
may be reduced to hydroquinones. Whether the black outer 
layers owe their color to phenoquinones, quinhydrones or higher 
oxidation products of the known pigments does not become ap¬ 
parent from Rennie’s investigations, though the red crystals be¬ 
tween the dark layers are apparently the trihydroxy com¬ 
pound. 
Pigments referable to di-dihydropJienyl-ethane . 
Di-dlhydro phenyl ethane 
Phoenteelne 
Phoenieeine 1 .) occurs as the colorless leueo-compound Phoe- 
nin in the heart of wood of Copaiefera bract eat a, the “purpur- 
holz” “amaranth wood’ 5 or “blue ebony” of South America, 
comprising about two per cent of the wood. Phoenin, 
C 14 H 16 O t> upon treatment with mineral acids gives up one 
1 Chem. News, 55, p. 115; Jr. Ohem. Soc., 51, p. 371; 63, p. 1083. 
1 Kleerekoper, E. Neederl. Tijdschr. Pharm., 13, p. 245 ; 284, 303. (Chem. 
Centralbl. 72, II, p. 858, 1085). 
