v COLOUR EFFECTS 25 



an image of the sun. As a matter of fact, the 6 

 drops fall too quickly to be able to form such an 

 image. The medium must be stationary in order to 

 receive the impression of what is to be reproduced 



How, then, it may be asked, does it come about ? 

 The drops, I reply, receive the colour, but not the 

 image of the sun. Besides, as Nero Caesar says 

 very elegantly : 



The neck of Venus' dove glitters as the bird tosses its head, 



and so the neck of the peacock shines with varied 

 colours as often as it is turned hither and thither. 

 Are we, therefore, to say that feathers of this kind, 7 

 whose every turn passes into new colours, are 

 mirrors? Well, clouds differ in character from 

 mirrors no less than the birds mentioned, and as 

 chameleons and the other animals whose colour 

 changes. In the latter case the cause is sometimes 

 subjective : the creatures when inflamed with anger 

 or passion vary their hue through the suffusion of 

 moisture : at other times the position of the light, 

 direct or slanting, gives the colour its particular hue. 

 What resemblance, I say, is there between mirrors 8 

 and clouds? Whereas those are not translucent, 

 these transmit light. Those are dense and com- 

 pact, these are rare. Mirrors are of uniform material 

 throughout, clouds are made up of various ele- 

 ments brought together at random, and therefore 

 are full of internal strife, and cannot long hold 

 together. Consider further ; at sunrise one sees a 

 certain portion of the sky ruddy ; at other times 

 one sees clouds of fiery red. This particular colour 

 is received by the clouds from encountering the sun : 

 what, then, is there to prevent the many colours of 

 the bow being derived by them in the same way 



