LIGHT MERELY VISIBLE. 



sunbeams into all the tints that are necessary or 

 even possible in the colouring of nature, we can 

 have no reason to doubt that the colours of nature are 

 all produced by the sunbeams. But, in consequence 

 of the great rapidity with which light moVes, we 

 must not confound the manner in which we see 

 painters make up their shades of colour by mixing 

 variously coloured substances, with the mode in 

 which the colours of nature are produced. The 

 light reveals the colours, but we are not warranted 

 in saying that it makes them ; for though, by means 

 of a common triangular prism, we decompose a 

 beam of light into the most perfect spectrum, and 

 keep that spectrum ever so long on the identical 

 piece of white paper, or any other surface, whatever 

 may be its colour, we shall never be able to find a 

 trace of the spectrum on the paper, or other surface, 

 after we remove it out of the light which the prism 

 decomposes. 



Now it is evident that, if the remaining colours 

 of the sunbeams did not in some way act upon the 

 surface, which gives out any particular colour, the 

 surface that shows any colour under the spectrum 

 would show the same whether the spectrum were 

 there or not, and as the same colour remains on the 

 surface after the spectrum has been removed that 

 was there before the spectrum was thrown upon it, 

 it is just as evident that every coloured surface must 

 have some peculiar state or property which disposes 

 it to show its particular colour. 



Hence it is evident that colour, and that which 

 we usually call light, is not a being or thing of any 

 kind, but merely a relation between one surface and 

 a reflection from another surface; that being the 

 case, we cannot regard light as in any way forming a 

 part of, or otherwise affecting, the quantity of matter 

 in bodies ; and, therefore, all such speculations as, 

 " whether the quantity of matter in the sun be di- 

 minished in consequence of the light which the sun 



