RELATIONS OF ETHER TO MOLECULES 65 



other colours in it ; and thirdly, of dispersing that colour. 

 In plants there is a substance called chlorophyl, which has 

 the power of absorbing part of the red and most of the 

 violet rays, leaving the extreme red, orange, yellow, and 

 green in considerable brilliancy. Their green colour is 

 not therefore simple but compound. 



The causes of absorption and scattering of colour are 

 very wonderful and very beautiful. The atoms of 

 different substances have their motions and capacities 

 for motion, and those waves are absorbed which fall on 

 them, and are in such relationship to them that they 

 can take up their motions, while those are scattered 

 whose motions they cannot take up. It is as when taps 

 are timed to the period of the swing of a pendulum, and, 

 being so timed, increase the oscillation, but not being so 

 timed the object tapping is sent out. Here then is a 

 magnificent and minute adjustment between the atoms 

 of matter and the ether. The capacity for motion of the 

 one is in its various measures arranged with reference to 

 the other. There is not an atom of matter, there is not a 

 point in the ether, that is not thus adjusted. As far as 

 the ether is concerned, and if chance only had been in 

 the field, there might not have been one atom of matter 

 having motions such as to absorb a single kind of wave, 

 and the motions of the ether might have been such that 

 no absorption would have been possible, and, in such a 

 case, the variety of waves would have been valueless, the 

 earth would have lacked the colours and tints that make 

 up its beauty, and would have been of one hue. But the 

 amount of adjustment for absorption is enormous, and 

 enables the earth to be clothed with loveliness of endless 

 variety. The molecules in grass, which give to it its 

 green colour, have their motions so arranged that they 

 can receive and swallow up so many motions of rays 

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