LIGHT, COLOR, AND SOUND 119 



124. Light and Color. The color of a body depends on 

 its nature, and the light in which it is viewed. A scheme of 

 color that is harmonious by daylight may be just the opposite 

 at night when viewed by artificial light. Different bodies 

 or substances, like dyestuffs, etc., owe their property of color 

 to the light that falls on them, and not to the body or sub- 

 stance itself. This fact may be illustrated by allowing 

 different colored lights to fall on the same substance, and 

 noticing the colors thus produced. 



Sunlight, as any other light, comes to us in the form of 

 waves vibrating at different rates. Each wave is one color, 

 and when they are mixed in a beam they produce white 

 light. Light may be separated into different colors or wave 

 lengths, by means of a triangular prism of glass, whereby 

 the rays are refracted and those with the greater vibra- 



INVISIBLE RAYS INVISIBLE RAYS 



FIG. 65. Spectrum. 



tion are bent more. In this way sunlight is separated 

 into its component parts. The colors thus obtained make 

 up what is called the spectrum (Fig. 65). The spectrum 

 contains red, orange, yellow, green, blue, indigo, and violet rays. 

 These rays are not all of the numerous components of white 

 light, but only the principal or primary ones. 



Light in a dry goods store, where fabrics are displayed, 

 should be diffused daylight, while in a ballroom a softer light, 

 rich in yellow and orange tints, is preferable. Every opaque 

 object assumes and reflects a color. A piece of red cloth 



