122 THE ANATOMY OF SCIENCE 



mode of thought in which the two following 

 laws will seem mutually harmonious. 



1. An atom possessing more than the mini- 

 mum amount of energy may suddenly lose its 

 superfluous energy, which travels as though it 

 were a single corpuscle along a definite path 

 with the velocity of light. The path is a straight 

 line except where it is deflected in the immediate 

 neighborhood of some material object, and in 

 such deflection both the corpuscle of light and 

 the other body obey the accepted laws of me- 

 chanics. 



2. A single corpuscle or quantum of emitted 

 light is subject to the laws of interference, or, 

 in other words, the interference is not due to 

 the interaction of a number of such corpuscles. 

 Thus if the light from a certain source pro- 

 duces dark and light interference bands on a 

 photographic plate, and this source is now re- 

 placed by a very faint source from which cor- 

 puscles are emitted only rarely, yet these cor- 

 puscles will strike the plate only where the 

 bright bands were formerly seen. 



If the phenomenon of light consisted of the 

 emission of energy in corpuscles and nothing 

 else, then in such an apparatus as shown in 

 Figure 22 a corpuscle would be reflected from 



