ELECTRONS AND ATOMS 29 



The doctrine of the conservation of matter 

 teaches that the sum total of material, or 

 matter, is constant or fixed however it chanced 

 to be or come there originally, and that matter 

 cannot be created or destroyed. 



The doctrine of the conservation of energy 

 teaches the same for the activities, or poten- 

 tial activities of matter, namely, that the 

 sum total of the various manifestations of 

 energy is a constant. Energy may pass from 

 one form to another, and the quantity present 

 in any given form may and does vary, for it is 

 the passage from one form to another, which 

 constitutes all natural phenomena ; but there 

 is no manufacture or destruction of energy, 

 there is the same quantity of energy in the 

 universe, as was in the beginning, and shall 

 be for ever. 



These two great tenets are fundamental in 

 the orthodox faith of the scientific world of 

 our day. Let us for the moment be daring 

 sceptics and examine them. 



In the first place the acceptance of these 

 doctrines as absolutely settled, places a limit 

 on our knowledge both of the past and of 

 the future. As regards the past, it becomes 

 agreed that no discovery is possible of how 

 matter originated, or activity in matter came 

 to exist, and in respect to the future, it is 



