THE EEASON W11Y. 117 



1 Light is sown for the righteous, and gladness for the upright in heart." 



XCVII. 



501. What causes the brilliant colours of the diamond ? 



The refraction of the rays of light by the various facets of the 

 diamond. 



The refraction of light, and the production of prismatic colours, surrounds us 

 with most interesting phenomena. The laundress, whose active labours raise 

 over the wash-tub a soapy froth, performs inadvertently one of the most delicate 

 operations of chemistry the chemistry of the imponderable agents and the 

 result of her manipulations manifests itself in the delicate colours that dance 

 like a fairy light over the glassy films that follow the motion of her arms. The 

 laughing child, throwing a bubble from the bowl of a tobacco pipe into the air, 

 performs the same experiment, and produces a result such as that which filled 

 the philosophic Newton with unbounded joy. The foam of the sea shore, the 

 plumage of birds, the various films that float upon the surface of waters, the 

 delicate tints of flowers, and the rich hues of luscious fruits, all combine to 

 remind us, that every ray of light comes like an angelic artist sent from heaven, 

 bearing upon his palette the most celestial tints, with which to beautify the 

 earth, and show the illimitable glory of God. 



CHAPTER XXIV. 



502. What is the difference between the refraction and 

 the reflection of light ? 



Refraction is the deviation of rays of light from their course 

 through the interference of a different medium ; reflection is the 

 return of rays of light which, having fallen upon a surface, are 

 repelled by it. 



503. What is the radiation of light ? 



The radiation of light is its emission in rays from the surface of 

 a luminous body. 



504. Do jail bodies radiate light ? 



All bodies radiate light ; but those that are not in themselves 

 primary sources of light, are said to reflect it. 



505. Do black bodies reflect any light ? 



Black bodies absorb the light that falls upon them. But they 

 reflect a very small degree of light. 



506 TP hy is glass transparent ? 



