428 SCIENCE PROGRESS 



Schunck and Marchlewski investigated in a systematic 

 manner the action of acids and alkalis on chlorophyll. 



Phyllocyanin and Phylloxanthin. — By passing hydrochloric 

 acid through an alcoholic solution of chlorophyll, Fremy had 

 previously obtained two products, of which one, to which he 

 gave the name phyllocyanin, was soluble in acids, by means of 

 which it could be extracted from ethereal solution, whereas 

 the other, which he called phylloxanthin, was insoluble in acids, 

 and remained in ethereal solution, when the latter containing 

 the mixture of the two bodies was shaken with hydrochloric 

 acid. Fremy assumed that phylloxanthin and phyllocyanin were 

 derivatived by the scission into two components of the pigment 

 originally in the plants. The observations of the French 

 chemist served as the starting-point of the investigations of 

 Schunck, who succeeded in obtaining the acid soluble phyllo- 

 cyanin in crystalline form. He also attempted to obtain a pure 

 phylloxanthin and, with Marchlewski, succeeded in showing 

 that the product soluble in ether as obtained by Fremy con- 

 tained, besides a decomposition product of chlorophyll, another 

 plant pigment, viz. carotin. The method employed for the 

 preparation of the acid decomposition products was as follows : 

 Fresh grass was extracted with hot alcohol, and the filtered 

 solution allowed to stand for some days ; a deposit was thereby 

 formed of wax and other plant substances. The filtrate from 

 these was then saturated with hydrochloric acid, and a separa- 

 tion of an almost black mass took place. This precipitate con- 

 tained the greater part of the phylloxanthin and phyllocyanin ; 

 it was almost completely soluble in ether, and the separation of 

 the two substances it contained was effected by shaking the 

 ethereal solution with an equal volume of concentrated hydro- 

 chloric acid. After separation of the aqueous and ethereal layers, 

 the latter was again shaken with fresh quantities of acid, and 

 the process repeated until the acid solution remained nearly 

 colourless. The combined acid extracts were allowed to stand in 

 open basins to evaporate off the ether, and then diluted with 

 water; a precipitate of phyllocyanin was thereby obtained, 

 which was purified by repeated recrystallisations from glacial 

 acetic acid. 



Phyllocyanin thus obtained formed a dark blue mass, re- 

 sembling indigo, of microscopic crystals, which decomposed 

 between 160 and 180 without melting; it was insoluble in water 



