PREFACE 



FOR more than twenty years, the general theme 

 treated in this volume has been under investigation 

 in my laboratory and my clinic, and the volumes 

 published during that time have recorded the steps 

 by which I have approached the theories here pre- 

 sented. 



The accumulated experimental and clinical data 

 are so extensive that summaries only are given in 

 the present volume, which is an argument for the 

 main thesis, that man is essentially an energy-trans- 

 forming mechanism, obeying the laws of physics, as 

 do other mechanisms. In presenting this thesis, cer- 

 tain hypotheses have been freely employed where the 

 data were insufficient that they may furnish a work- 

 ing basis upon which to accumulate additional data. 

 An hypothesis incomplete or even false is so 

 easily demolished that it can do little harm ; while 

 the presentation of a " false fact " may produce per- 

 nicious results. 



To no one are the imperfections and shortcomings 

 of this presentation more apparent than to the author, 

 who lays no claim to expert knowledge in any one of 

 the several sciences involved in attempting a synthesis 

 of such wide scope. 



A review of the literature and the details of most 

 of the researches whose conclusions are used in this 



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