CAROTIN, THE PRINCIPAL YELLOW PIGMENT OF MILK FAT. 321 



composition. A molecular weight determination of both the carotin 

 from the carrot and from the Brennessel leaves, by the ebullioscopic 

 method in carbon bisulphide gave an average of 533 which corresponds 

 exactly with 8(C 5 H 7 ) or C 40 H 56 . This shows that Arnaud's formula 

 of C 26 H 38 is not quite correct^ The same difference is brought out 

 by the analysis of the iodine derivative which Willstatter and Meig 

 also prepared. 



The absorption bands of carotin were measured by Willstatter and 

 Meig and they coincided almost exactly with those given, for it by 

 Tschirch * and Monteverde 2 . They did not attempt to measure the 

 third band in the violet which they considered to be end absorption, 

 but measured only the two bands in the blue and indigo blue. 



Willstatter and Meig Tschirch Monteverde 



(alcohol sol.) (alcohol sol.) (petroleum ether sol.) 



I 488-470 A I 487-470 A I 491-472 A 



II 456-438 A II 457-439 A II 461-444 A 



Carotin in Flowers, Fruits and Seeds. According to Czapek 3 caro- 

 tins have been identified in many flowers by Hansen, 4 Immendorff, 5 

 Kohl, 6 Tammes, 7 Hilger, 8 and his pupils, Wirth, 9 Pabst, 10 Kirchner, 11 

 Ehrung 12 and Schuler. 13 



Among the fruits, Arnaud, 14 Passerini, 15 Kohl, 16 Schunck 17 and 

 Montanari 18 have investigated the tomato pigment and believed it to 

 be a carotin. Its identity as a truly isomeric carotin has recently been 

 proved by Willstatter and Escher. 19 Schrotter 20 has shown that the 

 pigment of the pumpkin is in all probability a carotin and Desmoliere 21 

 has identified carotin in the apricot. 



1. Ber. d. deut. botan. Ges. 14, 76 (1896); 22, 414 (1904). 



2. Acta Horti. Petropolitani XIII Nr. 9, 123 and 150 (1893). 



3. Bichemie der Pflanzen, vol. I, p. 172, etc. 



4. 5, 6, 7. Loc. cit. 



8. Botan. Centr. 57, p. 335 (1894). 



9. Dissert. Erlangen (1891). 



10. Arch. Pharm. 230, p. 108 (1892). 



11. Dissert. Erlangen 1892. 



12. Botan. Cent. 69, p. 154 (1897). 



13. Dissert. Erlangen. 1899. 



14. Compt. Rend. 102, p. 1119 (1886). 



15. Compt. Rend. 100, p. 875 (1885). 



16. Loc. Cit. 



17. Proc. Roy. Soc. 72, p. 172 (1903). 



18. Le Staz. sp. agra. ital. 37, p. 909 (1904). 



19. Zeit. Physiol. Chem. 64, p 74 (1910). 



20. Vehr. Zool. bot. Gessel. 44, 298 (1895). 



21. Chem. Centr. 2, p. 1001, 1902. 



