THE RAINBOW. 219 



of dew, which make us imagine that one is green, another 

 rose-colored or orange, and another blue, are also illusions. 

 Each drop separates the beam of light which strikes upon 

 it into its component hues, or, rather, into the different vi- 

 brations, or other forms of force by which the conception 

 of these different hues are awakened in our minds, and 

 sends them off in different directions, and the drop that we 

 see seems to be of the color of the particular hue which 

 comes from it to our eye. If we move our eye a little way 

 we come into a position when a different portion of the 

 spectrum falls upon it, and the drop which a moment be- 

 fore looked red now looks green. Of course, of different 

 persons looking at different drops, no two would see the 

 same colors in the same drops. A drop that would send 

 a blue ray to one would send a yellow ray to another, and 

 to a third perhaps no light at all. 



Of course, when I speak of a ray of any specified color, I 

 mean a ray having the power to produce the sensation of 

 that particular color in our minds. 



The case is somewhat analogous to this in the phenom- 

 enon of the rainbow. When there is a dark cloud consist- 

 ing of falling drops of rain in the east, and the sun comes 

 out bright in the west, the rays, striking the drops, are 

 turned back by reflections and refractions, and are sepa- 

 rated into their component parts precisely as they are by 

 similar drops of water in the dew. These different classes 

 of rays are sent off from every falling drop in every possi- 

 ble direction, so that the whole atmosphere all around us, 

 and through the whole space between us and the cloud 

 is filled with these innumerable radiations, crossing each 

 other in every conceivable manner, but without any sensi- 

 ble interference, or interruption of one by the other, or 

 the least confusion in the sensations of color which these 

 immensely varied vibrations, if they are really vibrations, 



