THE CHLOROPHYLL APPARATUS 143 
In fig. 84 is a representation of the spectrum which 
such treatment produces and which is called, from the facts 
just narrated, the absorption spectrum of chlorophyll. The 
uppermost figure is that which is exhibited by an alcoholic 
solution or extract of leaves; the middle one is given by 
chlorophyll dissolved in benzol. The first band on the left 
is the darkest, and is found to be in the red part of the 
spectrum. The three bands on the right are broader, but 
are not so well defined. They cover nearly all the blue end. 
The three thinner and lighter bands are in the yellow and 
green parts of the spectrum. Chlorophyll therefore has 
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Fic. 84,—ABSORPTION SPECTRA OF CHLOROPH\LL AND 
XANTHOPHYLL, (After Kvaus.) 
the power of absorbing a large number of red rays, a good 
many blue and violet ones, and a few of the green and 
yellow. The distinctness with which these absorption 
bands are seen depends upon the strength of the solution, 
those in the red and blue being, however, always promi- 
nent. Careful experiments have proved that chlorophyll 
is a single pigment and not a mixture of two, as has often 
been stated. It is, however, easily decomposed, and the 
products of its decomposition are generally found with it 
in the chloroplast. One of these, Nanthophyll, which is 
of a bright yellow cclour, is always extracted with the 
