86 PRACTICAL LESSONS IN SCIENCE. 



which reflects all the colors of the light it receives is white; when 

 it reflects none it is black. The clouds both refract and reflect 

 the sun-light, and all their varied colors are due to the decompo- 

 sition of light by the water vapor in the clouds of the morning 

 or evening sky. 



The color of objects depends upon light. All objects are black 

 in the dark. When we paint our houses we apply to them a sub- 

 stance that has the property of reflecting the colors we desire 

 and absorbing the others. Thus bodies have no color of their 

 own. If a white body in a dark room be successively illuminated 

 by the colors of the spectrum, it appears red, yellow, orange, 

 green, etc., according to the light which illuminates it. 



Red, green, and violet are called fundamental colors, since, 

 with these, all possible colors may be formed by mixture. 



Two colors or tints which together give white are called com- 

 plementary colors. The following pairs of colors give white: 

 Red and bluish-green; orange and blue; yellow and indigo; 

 violet and yellowish-green. 



Spectrum colors differ from pigment colors. Pigment yellow 

 and pigment blue produce green, not white. 



