On the Colour of Leaves of Plants and their Autumnal Changes

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                                Having thus cleared the ground somewhat, I will first describe the character <s>istics</s> of the chlorophyll obtained by the action of alcohol of Sp. gr: 838 on the leaves of the Capucin arum, A. Arisarum, cut into small pieces. It may be presumed, that the chlorophyll thus obtained is of the same character as that procured from the green leaves of most plants, the <s>sop</s> sap of which is not strongly acid. The chlorophyll solution 
when freshly prepared in <s>bulbs <\s> bulk is very clear and of a brilliant 
grass green colour; this colour is preserved usually for some 
time, but the period varies; gradually when exposed to the 
air it loses its beautiful green <s>tune <\s> hue; it becomes in succession olive 
green, brownish green and dull coloured; its transparency is 
diminished and ultimately in the course of a few days, a 
reddish brown precipitate is thrown down, leaving the solution,
now deprived of much of its colouring matter, comparatively 
pale and with all its attractiveness destroyed. Usually when 
a small quantity of the alcoholic solution is evaporated in a 
capsule or watch glass, a grass green deposit is left, the exact 
tint of which varies with the quantity evaporated; if this 
be at all considerable it will be seen, that the principal 
part of the chlorophyll is deposited in a circle on the 
margin of the capsule and here in consequence it may present an 
almost black appearance, while in the centre it is <s>more <\s>
of a less deep grass green. 
It occasionally happens, that the alcoholic solution, when 
poured into a white porcelain capsule, in place of being 
                            
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Manuscript details

Author
Arthur Hill Hassall
Reference
AP/69/1
Series
AP
Date
1892
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On the Colour of Leaves of Plants and their Autumnal Changes, 1892. From The Royal Society, AP/69/1

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