90 
QUERIES AND ANSWERS. 
NATURAL HISTORY. 
The White Peach is one of those carious variations from the natural state 
of a species, the origin of which is as little known as the cause that may have pro¬ 
duced it. It is now well known, that whiteness in vegetation is very different from 
absence of colour: and that while the latter is caused by the total want of the co¬ 
louring-matter, or chromule of plants, the former is caused by the chromule being 
of some exceedingly pale tint: for as M. De Candolle has justly remarked, if an 
apparently white flower be placed before a perfectly white sheet of paper it will 
always he found to exhibit some tint of yellow, or pink, or blue, or green, &c. 
Cause of Colouring in Plants. —There is, perhaps, no subject of more 
interest than the cause of colouring in plants: it is one upon which till lately no 
very definite notions were possessed; but it has at length attracted the attention 
of the skilful vegetable-chemists of Geneva, and the phenomena relating to it 
are daily becoming more and more intelligible. It appears, that the opinion 
long since expressed by Lamarck, that when leaves and fruits acquire their au¬ 
tumnal colouring, they are in a morbid condition, and that flowers are, from 
their birth, in a state analagousto that of leaves in decay, is very near the truth. 
Taking the green colour so prevalent, and so frequently exclusive in vegetation, 
as the fundamental colour of plants, it appears that deviations from it are chiefly 
caused by their chromule being combined with oxygen in different degrees. 
When leaves are green, they absorb oxygen at night, and part with it by day: 
but just before they change their colour they cease to part with this gas, continu¬ 
ing however, to absorb it at night. Hence it has been inferred by Mr. Macaire, 
that oxygenation takes place, which in the first instance discharges the blue and 
and leaves the yellow, and next produces red; for in all cases red is preceded by 
yellow in leaves which change their hue. It is supposed that other colours may 
be caused by alkaline matter, or peculiar vegetable acids, being present, and that 
in what are called white flowers, the chromule is only in an imperfect condition; 
as apparent evidences of which, De Condolle points out, 1, the analogy of the 
colour with that of blanched plants; 2, the much greater proportion of white 
flowers in northern than in equatorial countries: and 3rdly, the well known fact 
that many flowers which are at first white become coloured afterwards.— Rot. 
Reg. 1586. 
PART III. 
% MISCELLANEOUS INTELLIGENCE. 
L—QUERIES AND ANSWERS. 
ERRATA in vol. iii. No. 31, page 1, line 12, for “ Forcing plants,” read 
Flowering plants. Page 40, line 4, for “ Raminiculaceae,” read Ranunculacew. 
Page 42, line 5 from the bottom, for “ green fleshed Keiseng, &,c.” read Green 
Fleshed , Keiseng , 8fc. Page 43, line 20, for “ Criosomra,” read Eriosoma. 
Heat in Vegetable Fermentation. How is it that in the process of ve¬ 
getable fermentation so great a quantity of heat is rendered sensible, besides the 
