CHLOROPHYLL. 101 
ow. The emerald-green color of leaves is thus a mixed color,’ 
and the spectruin of the leaf a mixed spectrum. While chloro- 
phyll only presents bands in the less refractive half of the spec- 
trum (red-green), and shows a continual absorption of the vio- 
let : in the case of xanthophyll there occur no bands at all 
(Fig. 32 s) between red and green, but only in the blue. Pure 
chlorophyll can be prepared, as one of us (‘T.) has shown, by the 
reduction of chlorophyllan, a crystallizable body. 
oBG 86D Et £ . f 
m5 ik 6s io et | 5D 45 j 
i) Ir 
Q 1 2 
i i Wit 4 
i HF ie 2 
u 4 3 
> vy 
t 2 
| | Bie j | ] | 
Fig. 32,—1. Spectrum of 2 leaves. 
2. Spectrum of 5 leaves. 
3. Spectrum of a dilute t alcoholic solution of pure chlorophyll. 
4. Spectrum of a concentrated 
5. Spectrum of an alcoholic solution of xanthophyll. 
In the leaf spectrum, band 2 of the xanthophyll is mostly covered by the projecting ter> 
minal absorption of the pure chlorophyll; at least it is always rendered unclear 
(Tschirch). 
The chlorophyll granules of the higher plants always appear 
as roundish, disk-like bodies (Figs. 33, 109, 129, 161), which, 
'By means of benzol, as has been shown by G. Kraus (‘‘ Zur Kenntniss 
der Chlorophyll-Farbstoffe,”’ Stuttgart, 1872), an alcoholic tincture of 
chlorophyll from leaves may be split into two layers, a yellow lower 
layer containing xanthophyll, and a green upper layer which contains 
the chlorophyll. The separation is, however, not quantitatively exact. 
(Tschirch, ‘‘ Untersuchungen iiber das Chlorophyll,” Berlin. Parey, 
1884.) 
