PHYSICAL PARADOXES. 



a later section, and a brief account of it must 

 suffice here. 



It is agreed that atoms, the smallest portions 

 of matter known till quite recently, consist of 

 still smaller particles or corpuscles, which vibrate 

 with enormous energy within the atoms. A 

 small proportion of the atoms of all substances 

 are continually disintegrating or breaking up. 

 Radium only differs from other substances in 

 that this proportion is in its case much higher 

 than in theirs. The component parts, cor- 

 puscles, and groups of corpuscles fly out from 

 the disintegrating atoms with a speed propor- 

 tionate to the enormous energy with which they 

 were vibrating within it, speeds of from 15,000 

 to 150,000 miles per second. Striking one 

 another and adjoining particles of radium at 

 this velocity, they develop an amount of heat 

 which in proportion to the amount of matter 

 involved is enormous. 



Thus the heat constantly given out by 

 radium is the natural result of a definite 

 process constantly going on, and as this 

 process involves degradation of energy and 

 disappearance of substance there is no con- 

 tradiction of the great law of conservation. 



The loss of substance is so slow that it is 

 imperceptible for the time during which radium 

 has been under our observation ; but in spite 

 of this the results of the action are appreciable 

 because the power is relatively enormous which 



i So 



