COLOUR DEPENDS ON CLIMATE. Ill 



cloudy day, my results would be the same as yours. Let me 

 advise you, my frieud, to make your carmine on bright sunny 

 days.^ ' I will,^ says the Englishman, ' but I fear I shall make 

 very little in London.' " 



Now this anecdote may be depended upon ; for a person so 

 distinguished as a chemist and natural philosopher as Sir 

 Humphrey Davy would not have related a story in regard to 

 the effect of light, which was contrary to truth, or which he did 

 not directh^ know to be true. 



And if the effect of sunshine is so great on colour, as that the 

 increase or decrease of its brilliancy should cause a totally 

 different result to follow from the combination of precisely the 

 same chemical ingredients, it will readily follow that much more 

 effect will be produced by its excess in one case, or almost total 

 exclusion in another, upon hues so changeful as those which 

 glitter on the scales of a fish. 



That in a pure limpid rapid stream, rushing over a bright 

 gravelly bed, through open fields, where no envious boughs 

 intercept the sunlight, and in a dark turbid pond, the waters 

 of which are saturated with the draining of peat-bogs, or 

 with the juices of decomposed vegetable matter, and over- 

 shadowed by thick evergreen umbrage, the light even of the 

 most gorgeous noon will be transmitted in very different degrees, 

 and produce very different effects both of colour, heat, and 

 radiance, any person can judge, who will observe the sunbeams 

 as they fall through a sheet of pure plate-glass, or a thick green 

 bull's-eye; and that the consequences may easily be as they are 

 stated above, he will, I think, be satisfied. 



Now, in the first place, analogous to this, and in corroboration 



