904 Wisconsin Academy of Sciences, Arts, and Letters. 
PIGMENTS REFERABLE TO HYDROCARBONS OF THE FORMULA OF SAT¬ 
URATION C n H 2n - 24 . 
Falling under this degree of saturation are the isomeric car¬ 
otin and lycopin, hydrocarbons of unknown constitution, prob¬ 
ably derivatives of fulvene. 1 
CH - CH 
CH CH 
fetes* 
Carotin is the yellow pigment of the carrot, Dances carota. It 
is supposed to be very widely distributed in the plant kingdom, 
being the yellow pigment which almost universally accompan¬ 
ies chlorophyll. Carotin was probably isolated by Fremy 2 as 
early as 1865 and later by others investigators who obtained red 
crystalline substances from green leaves. It is probable that 
the chrysophyll of Hartsen, 3 the erythrophyll of Bougarel 4 and 
the xanthin of Dippel 5 were identical with carotin. 
In 1885 Armand 6 easily obtained from dried green leaves, 
by extraction with petroleum ether a yellow pigment which, puri¬ 
fied with ether, formed orange red crystals. To this substance 
which corresponded with the pigment from carrots Armand 
assigned the formula C 26 H 38 . Later investigations by Will- 
staetter 7 have shown the true formula to be C 40 H 56 . 
Lycopin, isomeric with carotin is the red pigment of the to¬ 
mato, Lycopersicum escnlentum. This pigment was formerly 
supposed to be identical with caroten. In 1904, Montanari 8 
recognized its difference from carotin and called it dicarotin, 
C 52 H 74 (Carotin C 26 H 37 ). According to the later work of 
1 Zeit. Physiol. Chem., 64, p. 47. 
2 C. r., 61, p. 189. 
8 Arch., Pharm., 207, p. 136. 
4 Ber., 10, p. 1173. 
B Flora, 1878, p. 18. 
«C. r., 100, p. 751; 102, p. 1119, 1319. 
7 Ann., 355, 1. 
8 Staz. sperim. arga. ital., 37, p. 909. Wehmer, p. 686. 
