HOW THE BRAIN THINKS 



THE idea of a chemistry of the living body, of 

 bones and muscles and secreting glands, is not new. 

 It was Lavoisier, for example, who showed that 

 the work of the lungs, taking up oxygen and giv- 

 ing off carbonic acid, is a simple chemical process, 

 much like the burning of coal in the grate or the 

 rusting of iron. And the butchers of the French 

 Revolution had stilled the workings of his splendid 

 brain before the eighteenth century closed. 



The chemistry of mind is more recent. It was 

 about a half -century ago that a reflective German, 

 gathering together the scant results of his day, 

 formulated his famous aphorism: 



"Ohne Phosphor, kein Gedanke" without 

 phosphorus, no thought. 



That was not the beginning of the endeavor to 

 find out how we think. The anatomists had been 

 busy for a half -century before. And they have 

 been still more industrious since. Thanks to them, 

 we have now a marvellous picture of the minute 

 structure of the brain and the nerves. They can 



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