178 THE NEW KNOWLEDGE. 



is not greater than the energy of the X-rays falling upon 

 it the excess of energy being derived from re-arrange- 

 ments taking place in the atoms of the body exposed to the 

 primary X-ray bombardment. It is conceivable that some 

 such method of attack might lead to a way of doing by ex- 

 ternal agency what radio-active bodies can do spontaneously, 

 i. e., liberate the energy locked up in the atom. It has 

 been playfully suggested by Professor Rutherford that some 

 day it might be possible to construct a detonator which 

 would send a wave of atomic disintegration through the 

 earth and decompose the whole round world into helium, 

 argon, and other gases, leaving literally not one stone upon 

 another. Without being frightened by any such humorous 

 suggestion as this, we can easily grant that with the con- 

 tinuous acceleration of scientific research where one year 

 of the present counts for a cycle of former time, there will 

 come a day in the unending succession of days when men 

 will look with mingled horror and amusement at the burn- 

 ing of coal and wood, and will date the coming in of their 

 kingdom to the time when Curie and Laborde demonstrated 

 the existence and extent of intra-atomic energy. 



