SCIENCE, EDUCATION, RELIGION 



705 



COLLEGES AND UNIVERSITIES OF THE UNITED STATES Con. 



Color is the name given to distinguish the 

 rious sensations that lights of various rates 

 vibration give to the eye. As is the case 

 ith many of the words that denote our sensa- 

 i>. the word color is also applied to the prop- 

 es of bodies that cause them to emit the 

 lit that thus affects our senses. The molecular 

 titution of a body determines the character 

 number of the light vibrations it returns to 

 B eye, and so gives to each body its own charac- 

 color; hence the term color is used to 

 >te that in respect of which bodies have a 

 ferent appearance to the eye independently 

 their form. 



Ordinary white light (the light which comes 

 m an incandescent solid or liquid) when trans- 

 tted through triangular prisms of glass or 

 er media differing in dispersive power from 

 atmosphere, is shown to consist of a number 

 colored light*, which, meeting the eye, together 

 uce the sensation of white light. The colors 

 .shown are usually said to DC seven red. 

 ge, yellow, green, blue, indigo, violet; al- 

 ility there is an enormous, if not 

 infinite, number of perfectly distinct colors 

 light. I he seven colors are frequently called 

 primary colors, and other tints and shades 

 producible by mixing them; but in astrictrr 

 he primary colors are three in number, 

 namely, red, green, and violet (or blue). These 

 < lors or kind.s oi" li^ht cannot be resolved 

 intoany other. In the scientific senseof the \\.rli 

 white and black arc not considered colors, a 

 1 Kxly reflecting and a black body absorbing 

 all the rays of light without separatum them, 

 is the colors proper are due to separation 

 of the rays of light by partial absorption and 

 n <>r by refraction. If a body absorbs 

 every other kind of light and reflects or tra 

 red light only, it will appear of a red color; if 



it absorbs every kind except blue rays, it will 

 appear blue; and so on. If more than one kind 

 of light be transmitted or reflected the object 

 will appear of a color compounded of these differ- 

 ent rays of light. 



In art the term color is applied to that com- 

 bination or modification of tints which produces 

 a particular and desired effect in painting. The 

 colors of the spectrum have to be distinguished 

 from colors used in reference to pigments. The 

 pigments red, blue, and yellow, regarded in the 

 arts as the primary colors, produce effects. 

 when mixed, very different from those produced 

 by admixture of the corresponding spectrum 

 colors. These three pigment colors form other 

 colors thus: red and yellow make orange, yellow 

 and blue make green, and red and blue' make 

 purple; but red, blue, and yellow cannot be 

 pro* lured by any combination <>f the other colors. 

 il colors are those which are natural to a 

 particular object in a picture, and by which it is 

 distinguished from other objects. Neutral 

 colors, those in which the hue is broken by par- 

 taking of the reflected colors of the object s*\\ hi< -h 

 surround them. Positive colors, those which are 

 unbroken by such accidents as afl" 



('<>ni}>lcmcntan/ colors, colors which 

 together make white; tims any of the primary 

 colors is complementary to the other two 

 jcctivc or accidental colors, the imaginary comple- 

 mentary colors seen after fixing the eye for a 

 short time on a bright-colored object, and then 

 turning it suddenly to a white- or light-colored 

 surface. 



Combustion. The operation of fire on 

 inflammable :l>stnnccs; or the union of an in- 

 flammable s M l,.tanci' \\itli oxygen M- some other 

 supporter ,,t oombllfl > d with heat and 



iiisianrrs \\ ilh light. I: 



the combination of the carbon in fuel with the 



