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Some Notes on the Mechanism of Light and Heat 



Radiations. 



James E. Weyaxt. 



In all the realm of the natural sciences there has been no more fascinating 

 and elusive problem than that relating to the mechanism involved in the 

 transmission of light and heat. How energy may be transmitted at a dis- 

 tance; what action is involved at its source; what properties matter may 

 possess that this may proceed over vast spaces; what atomic and molecular 

 changes are involved in the emission and absorption of light and radiant 

 heat, are all questions involving the ultimate structure of matter and are as 

 yet incapable of complete solution. 



Some of the familiar types of wave motion we observe in nature; for 

 instance, wave motion in water; the transmission of sound waves through 

 air, water and various solids are of such a character as to be easily repro- 

 duced under conditions whereby they can be accurately measured, their 

 origin determined and their mode of propagation analyzed. In case of 

 vibratory motion in matter capable of affecting the auditory nerve or in 

 other words of producing sound, the mechanism is comparatively simple. 

 As to source we have a material body, executing some form of simple har- 

 monic motion; these vibrations being "handed on" to adjacent particles in 

 a periodic disturbance or wave. This propagation stops, however, when 

 the limit of matter has been reached, i. e., sound waves cannot traverse a 

 vacuum. In all this process, matter has been concerned, both in the origin 

 and the propagation of the wave motion. In light and heat waves, matter 

 is concerned, also both in its production and absorption; but in its propaga- 

 tion they do not appear to depend in any way upon the presence of matter, 

 as they pass readily through the best vacua and traverse the vast inter- 

 stellar spaces with apparently the greatest ease. 



Since we find that all radiations of light and heat energy originate in mat- 

 ter we must find the mechanism necessary for their production intimately 

 involved in the constitution of matter itself. The kinetic theory served to 

 give an incomplete mental picture of this mechanism and upon it was based 

 many of the hypotheses of the past. 



Various electrical and optical phenomena have been explained upon 

 the ground of ether disturbances. These disturbances have been inter- 



