166 Mr. C. A. Schunck. The Xanthophyll [Apr. 17, 



and ultra-violet region of the spectrum and which occur along with 

 the xanthophyll in greater or less quantity in all flowers. In some 

 flowers they are almost absent, while in others (as, for instance, the 

 yellow calceolaria) they are present in a large quantity compared to 

 the xanthophyll, and in the yellow dahlia the pigment is entirely 

 comprised of them. These colouring matters are soluble in boiling 

 water and alcohol, sparingly soluble in ether, but appear to be insoluble 

 in carbon-bisulphide, and towards alkalies behave in a different manner 

 to the xanthophylls, the alcoholic extracts becoming deeper yellow, 

 in some cases orange, and in others (as from the yellow dahlia) brick- 

 red, on addition of ammonia, and crimson with sodium hydrate, the 

 original yellow colour being reproduced on neutralising with acid. 

 On the other hand, alkalies appear to have no action upon the members 

 of the xanthophyll group and saponifying does not appear to alter 

 them. 



It is essential for the spectroscopic investigation of the xanthophylls 

 that the above-mentioned colouring matters be first got rid of. For if 

 not, the bands of the former are obscured by the general absorption of 

 the latter, and I find the separation by means of carbon-bisulphide 

 preferable to extracting the petals first with boiling water, whereby 

 they can also be removed, as this has a tendency to affect certain of 

 the xanthophylls, due perhaps to the acid contained in the cell-sap. 



The separation by carbon-bisulphide is effected by agitating the 

 extract several times with equal quantities of the solvent until no more 

 pigment is taken up ; the several carbon-bisulphide portions or fractions, 

 which vary from three to four in the case of flowers, are allowed to 

 spontaneously evaporate and the pigment taken up again with alcohol, 

 and then each is examined spectroscopically together with the original 

 alcoholic extract lor comparison, as well as the pigment contained in 

 the fatty deposit and that remaining in the alcoholic extract after the 

 carbon-bisulphide separation. 



The results of the spectroscopic observations of the various flowers 

 experimented with, show the presence of three yellow colouring 

 matters, each giving, like chrysophyll, the crystalline substance 

 obtained from alcoholic extracts of the green leaf, three pronounced 

 absorption bands in the violet region of the spectrum, and are further 

 characterised and distinguishable from one another by giving a different 

 spectroscopic reaction with acid which, in the case of two, is very 

 definite and sensitive. Though spectroscopically there appears to be 

 good evidence of the existence of three distinct colouring matters, yet 

 trying various means I failed to obtain them in the crystalline form 

 or in sufficient state of purity, free from the accompanying fats, etc., 

 to be able to examine their chemical properties, pending which it will, 

 1 think, be sufficient to term them for the present L. B. and Y. xan- 

 thophyll. They are distributed as follows in the flowers examined : 



