414 T^A^ Inward Urge to Change 



the " laws " of the psychologist and of the economist, since 

 the latter do not make clear a mechanism which the chemist 

 can follow. 



The physicist derives his " laws " by the observation of 

 physical phenomena. He analyzes the actions and inter- 

 actions of material bodies, of liquids and gases, under various 

 conditions, under the influence of various forces. The uni- 

 formities which he finds he accepts as in the nature of the 

 material with which he is working. He records what he 

 sees, and he sees what comes to his eyes, without prejudice. 

 The chemist pursues similar methods. These prosaic con- 

 centrations upon the commonplace materials that we find 

 everywhere at hand have revealed striking and astonishing 

 facts. Yet it was impossible to know in advance, for ex- 

 ample, that a current of electricity passing around an 

 empty space would make the hollow behave like a magnet. 

 It was impossible to predict that a discharge of electricity 

 through a vacuum tube would result in shooting out rays 

 that could penetrate wood and leather and human flesh. 

 From a thorough study of the qualities of silver and bromine, 

 nobody could possibly have foretold a photograph, to say 

 nothing of moving pictures. 



Each set of facts as they come under notice are ac- 

 cepted without prejudice as having their legitimate place 

 in the nature of the world. Neither the chemist nor the 

 physicist attempts in the first instance to " explain " the 

 events of one order in terms of the lower order. Each at- 

 tempts to discover the constants and uniformities of the 

 phenomena as given in his own field. Thus, the chemist 

 analyzes matter into elementary substances, and conceives 

 these to consist of uniform ** atoms." He studies the atoms, 

 qualitatively and quantitatively, and discovers among other 

 things that almost any two kinds of atoms can form a new 

 substance or compound. He studies the qualities of these 

 compounds again without prejudice: that is to say, he does 

 not introduce any a priori dogma as to what these new com- 

 pounds ought to do, how they ought to behave, what prop- 



