283 
Some Nores ON THE MECHANISM OF LIGHT AND Hk&at 
RADIATIONS. 
JAMES EH. WEYANT. 
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- 
