88 Schunck . — The Chemistry of Chlorophyll. 
had been dissolved along with the colouring matter. The 
deposit having been filtered off, a current of hydrochloric acid 
gas is passed through the filtrate. This produces at once a 
dark green, nearly black voluminous precipitate, which in- 
creases in quantity on standing. The precipitate is separated 
by filtration from the greenish -yellow liquid, containing 
colouring and other matters extracted along with the chloro- 
phyll, and then washed with alcohol in order to remove these 
together with the excess of acid. The precipitate contains, 
mixed with impurities chiefly of a fatty nature, two distinct 
colouring matters, which are identical with the phyllocyanin 
and phylloxanthin of Fremy. These names I have seen no 
reason to change, though they are not perhaps very appro- 
priate. The method which I adopt for separating the two 
substances is essentially the same as that of Fremy. The 
crude product of the action of the acid is first treated with 
ether in which nearly the whole dissolves. The insoluble 
matter having been filtered off, the filtrate is mixed with 
about an equal volume of strong hydrochloric acid. The 
mixture after being well shaken is left to stand, when it 
separates into two layers, an upper yellowish -green one, 
containing phylloxanthin, and the greater part of the fatty 
matters, and a lower dark blue one containing phyllocyanin 
in combination with hydrochloric acid. The two liquids are 
separated in the usual way and with as little delay as possible 
— since on standing the phylloxanthin begins to dissolve in 
the hydrochloric acid and passes gradually into the lower stra- 
tum — and the blue solution is agitated with ether, the process 
being repeated until the ether takes up no more colour. The 
solution, after exposure to the air, to allow the ether contained 
in it to evaporate, is mixed with water which produces a dark 
blue precipitate. This is filtered off, washed to remove the 
acid, and then dissolved in boiling glacial acetic acid. This 
solution gives on cooling a crystalline deposit of phyllocyanin, 
which is filtered off and recrystallised from boiling acetic acid, 
finally washed with alcohol and dried. By the process just 
described I obtained phyllocyanin from ivy leaves, from the 
