IOO VEGETABLE SUBSTANCES. 



and later, often after a number of hours, blue, by 

 hydrochloric or sulphuric acid. 



b. XANTHOPHYLL (B'erzelius, Pringsheim), 



The yellow coloring matter of autumnal leaves, is 

 insoluble in water, but soluble in alcohol and ether. 

 It is only colored emerald green by the acids which 

 have been named. 



c. ANTHOXANTHIN (Marquart, Pringsheim), 



The yellow pigment of yellow flowers, fruits and 

 seeds, occurs, like chlorophyll, diffused through 

 protoplasmic bodies ; less frequently in the form of 

 yellow oily drops; and very rarely diffused in the 

 cell-sap. The latter variety (anthochlor, Prantl ; 

 xanthein, Fremy) is soluble in water, in which the 

 other forms are insoluble, though they are soluble 

 in ether and alcohol. The varieties of anthoxan- 

 thin (xanthein, Fremy; lutein, Thudichum), which 

 are soluble in the latter reagents, are colored green 

 like xanthophyll, but later, like etiolin, blue, by the 

 action of acids ; those soluble in water, however, 

 are not affected in this way. Anthochlor becomes 

 brownish yellow when treated with potassic hy- 

 drate, but the original color returns when the 

 solution is neutralized. 



