152 



Plant Pigments 



[March, 



tions. The following methods were used : loo k. of dry leaves were 

 extracted with 120 1. of petroleum ether (b. p. 40°-70°) in the cold 

 for two days, the extract filtered off and the residue washed with 

 60 1. of petroleum ether. The extract was shaken with a Httle conc. 

 alcohohc potash sol. to remove Chlorophyll, then with water, con- 

 centrated to about 3 1. and allowed to crystallize. After shaking 

 with I 1. of low-boiling petroleum ether, the product was purified by 

 repeated precipitation from carbon disulfid sol. with absolute 

 alcohol. Finally it was recrystallized from petroleum ether (b. p. 

 30°-50°). The yield was 3.1 gm.-0.03 gm. per k. of dry leaves. 



Data pertaining to some plant pigments 



Modifications of the above method, in which mother liquors 

 from the preparation of Chlorophyll were used, are given by Will- 

 stätter and Stoll.^ The Carotin was found in the petroleum ether 



3 Willstätter and StoU : Untersuchungen über Chlorophyll, p. 239. 



