584 SCIENCE PROGRESS 



And again : 



" If a metal contains particles which can vibrate with i 

 definite frequency determined by their nature, how does r 

 happen that these vibrators remain quite mute until a suffi 

 ciently high temperature has been reached? And if, insteac 

 of such vibrators, we prefer to think of irregular movement; 

 in matter, producing a like state in the ether, which we resolv( 

 into harmonic vibrations by an arbitrary and artificial process 

 how are we to understand why in this analysis the high fre 

 quencies disappear completely when the total energy diminishes' 

 It is not possible to suppose that there is no connection betweer 

 the light waves and the phenomena which go on inside a cole 

 body, because, after all, the body absorbs light although il 

 does not emit it. A mechanism must be invented which wil 

 permit the passage of energy under the form of rapid vibra^ 

 tions from the ether to the ponderable matter, but which 

 excludes the passage in the opposite direction." 



But when we consider the X-ray phenomena, and that 

 X-rays are only light rays of high frequency, we see that there 

 is here an effect of which older theories took no account. Its 

 consequence is to prevent the radiation energy going intc 

 higher frequencies, which is just what is wanted. Whether it 

 is a sufficient explanation is another matter. All that can be 

 said at present is that such an event is anything but improbable. 

 There are excellent reasons for supposing that there are elec- 

 trons in movement in the interior of any substance, at any 

 rate of any substance that conducts electricity ; and that 

 these electrons are the means whereby electricity and heat are 

 able to move across the substance. It is also most probable 

 that the velocities of the electrons are distributed according 

 to Maxwell's law. 



From what we have seen above there must be X-rays or 

 high-frequency radiations to match. The rules which govern 

 the rate at which X-ray energy is commuted into electron 

 energy in crossing a given quantity of any material are becom- 

 ing fairly well known ; the rules of the converse operation are 

 not so well known, though some work has been done on the 

 subject. When the rules of exchange are known accurately, 

 it will be possible to calculate the balancing amount of X-ray 

 and electron energies. It looks at present as if all might come 

 out right, and that we may be able to reach an explanation of 

 the old radiation difficulty. 



