ioo Schunck . — The Chemistry of Chlorophyll. 
caustic soda lye, I have already alluded to. According to 
Tschirch, chlorophyll is converted by the action of alkali into 
what he calls chlorophyllinic acid ; Hansen’s chlorophyll-green 
would then be the sodium salt of this acid. Tschirch, as well 
as Russell and Lapraik, state that after treatment with alkali 
chlorophyll becomes much more stable, both on exposure to 
light and on treatment with acids. This in itself would tend 
to prove that a chemical change has been induced by the 
alkali leading to the formation of a product, which we may 
call a modification of chlorophyll, if we choose. The experi- 
ments which I have made, and of which I shall now give a 
short account, render it all but certain that this is the case 1 . 
Fresh leaves— grass being the best material to use — are 
exhausted with boiling spirits of wine containing from 80-82 
per cent, of alcohol. The green extract is filtered hot, and 
being allowed to stand for a day or two away from the light, 
yields a dark-green voluminous deposit, containing chlorophyll 
mixed with fatty and other matters. This deposit is filtered 
off for further treatment, the pale-green filtrate being rejected. 
The green mass on the filter is now to be treated with a boiling 
solution of soda in strong alcohol, which dissolves it in part. 
After standing some time the insoluble portion, consisting of 
fatty matter etc., is filtered off, and a current of hydrochloric 
acid gas is then passed through the dark-green filtrate until 
it acquires a strong acid reaction. The liquid first becomes 
yellowish-green, but after some time the colour changes to 
a dull purplish-green, and small crystalline needles, arranged 
in stars, purple by reflected and dull green by transmitted 
light, begin to appear on the sides of the glass, and continue 
to increase in quantity for some time. The crystalline sub- 
stance thus obtained is filtered off, washed with alcohol, and 
purified by treatment with ether, which removes some fatty 
matter ; it is then dissolved in a little chloroform, and this 
solution is mixed with several times its volume of absolute 
alcohol, when the substance is again deposited in long crystal- 
line needles. Under the microscope these are seen to consist 
1 Proceedings of the Royal Society, XLIV. 448. 
