The Evolution of the Sciences 



sciences, and of all men, even the greatest 

 scientists, to form castes. So the chemists 

 pretended that the principle of maximum work 

 remained valid provided that one took into 

 account in a reaction only energy of an ex- 

 clusively chemical nature, and excluded, as 

 foreign, all manifestations of energy attributable 

 to external or physical causes. 



This type of argument involves the erection 

 of a watertight partition between chemistry 

 and physics, but Nature knows no such absolute 

 boundaries; phenomena form a whole which 

 cannot be divided to suit our taste. Of what 

 nature are solutions, fusions, polymeric trans- 

 formations? Are they physical or chemical? 

 We are absolutely unable to tell. How is a 

 foreign energy introduced into the just-men- 

 tioned mixture of alcohol and acetic acid by 

 keeping its temperature at 100 C.? In what 

 way does this differ from keeping it at the 

 ordinary temperature, or at any other tempera- 

 ture? Moreover, and this is a characteristic 

 example, what right have we to pretend that 

 when the electric current decomposes sulphate 

 of zinc in a voltameter it is acting as physical 



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