808 NATURE OF CHLOROPHYLL. 
M. Frémy has investigated the nature of chlorophyll, and 
ascertained that it is composed of two colouring principles,— 
one ayellow, which he has termed phylloxanthin or canthophyll ; 
and the other a blue, which he has called phyllocyanin or cyano- 
phyll. Both these principles have been isolated by M. Frémy, 
who has also endeavoured to show that the yellow colour of 
etiolated and very young leaves is due to the presence of a body 
which he has termed phyllawanthéin, and which is coloured blue 
by the vapour of acids. The same principle results from the 
Fig. 1148. 
i A IV 
Fig. 1148. Absorption spectra of chlorophyll and xanthophyll. (After Kraus. ) 
The upper spectrum is given by an alcoholic extract of leaves, the middle 
one by dissolving chlorophyll in benzol, and the lowest by xanthophyll. 
The bands in the least refrangible portion B-§E are figured as obtained 
with a concentrated so’ ution; those in the most refrangib.e part of the 
spectrum F-G are given as obtained with a weak solution. The letters 
B-G indicate the principal rays, the numbers I-viI the absorption bands 
of chlorophyll from red to violet, and the figures 0-100 divide the length 
of the spectrum into 100 equal parts. (After Sachs.) 
decoloration of phyllocyanin ; hence it would seem that phyllo- 
cyanin is not an immediate principle, but that it is formed 
by the alteration of phylloxanthéin. The experiments of M. 
Filhol do not, however, altogether correspond with those of 
M. Frémy, whilst the more recent spectroscopic investigations 
of Professor Stokes and H. L. Smith tend to show that chloro- 
phyll is more complex than M. Frémy imagined. 
Chlorophyll is stated by Sorby to exist in a blue and also 
in a yellow state, giving different effects with the spectroscope, 
and Kraus finds that by shaking up an alcoholic solution of 
chlorophyll with benzol, two clearly separated strata are formed, 
a lower alcoholic one of a yellow colour, and an upper one of 
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