12 LIGHT A COMPOUND JS MATERIAL SOURCES. 



in attaining their respective positions for the junction of their 

 POLES, when changing from the insulated to the RADIANT linear 

 state, may exhibit undulatory motion, but the projection of RE- 

 DUNDANT light from an emanating point is essential to produce 



IMPETUS, PRESSURE, and CONTACT. 



. 



1st. Light is a material compound, composed of the three 

 simple elementary principles or uridecompounded constituents 



of which all other bodies in nature are formed. 



^ 



LIGHT is that radiant state to which fixed or inert matter is 

 resolved. It is (as here presumed) a ternary compound of 

 oxygen, nitrogen, and hydrogen, combined by one positive and 

 two negative poles, in the centre of each atom, assuming a 

 spherical corpuscular form ; the primary molecules of which 

 are readily separable from combination, and from their minute 

 state are most appropriate to enter into new and immediate 

 combinations with bodies of fixed matter, in which shape they 

 reappear, displaying in the regular series of alternate transition 

 all the beauty and variety visible in surrounding objects. 



The materiality of light has been admitted since the days of 

 Newton. Its properties with respect to vision and its particu- 

 lar laws, defined under the science of optics, it is not intended 

 to discuss, although from its chemical relations, which are the 

 more immediate objects of the present inquiry, the mention of 

 refraction, reflection, velocity, c., is unavoidable. 



The sources of light are three: 1st. The sun, or its atmo- 

 sphere, by direct emanation. 2nd. The other heavenly bodies, 

 by reflection. 3rd. The resolution of faced into radiant matter 

 by combustion or decomposition ; the electric or galvanic action. 



Of the physical cause by which light is emitted by the 

 sun, man is likely to be ever ignorant at this side the grave ; 

 it is numbered among the wise arrangements repressive of his 



