344 GENERAL SCIENCE 



of light to be reflected. If a red glass be used in the spectrum 

 beam, any blue object upon which the red light falls will 

 appear black, and a white body as a screen will look red in 

 the red light which falling on the screen suffers reflection. 

 Color in itself is just a light phenomenon due to the kind 

 of light affecting the eye. Color as a property of bodies is 

 determined by what color elements of any incident white 

 light are reflected from it, and in what proportions. Thus it 

 is that "selective absorption" accounts largely for the 

 colors of objects round about us with all their wonderful 

 variations. An object is said to be white when it reflects 

 all the color elements of the white light incident upon it. 



Light reflected from bluing left in cotton cloth, combined 

 with the yellowish light reflected by the natural coloring material 

 in the cotton fibre, causes when received into the eye quite 

 the same color sensation as does sunlight when reflected 

 from a white wall. It is an illustration of what is meant by 

 ' ' complementary colors . ' ' 



The theory that light is wave motion in an ether medium 

 explains color phenomena. The mathematical accuracy 

 of the theory is very striking. Briefly, the theory for color 

 is that the nerves of sight seem to be attuned to respond to 

 certain very definite numbers of vibrations per second coming 

 to them as " ether waves". The eye is able to distinguish 

 more or less sharply between at least seven different sets 

 of these vibration rates the so-called spectrum colors. 

 This is very much the same condition for the eye as that 

 which enables the ear to distinguish vibration rates coming 

 to it through the air or other material medium as the "tones" 

 of music. The richness (quality) of any sound is increased 

 by the blending of certain combinations of sound waves per 

 second, making possible all the variations whereby we 

 are enabled to distinguish the voices of our friends and 

 acquaintances wherever heard. In like manner the blend- 



