VITAMINES, UNKNOWN BUT ESSENTIAL 

 ACCESSOHY FACTORS OF DIET 



In many departments of human knowledge the 

 teaching and guidance of science are accepted as 

 final because in these departments the knowledge 

 arose in the first instance from scientific studies 

 and from these alone. Progress in such categories 

 depends entirely upon controlled and recorded 

 observation or upon experiment, and these are 

 the methods of science. 



It is otherwise, one might be tempted to say, in 

 regions where mankind can claim abundant and 

 accumulated empirical experience. In connexion 

 with his own nutrition Man's experience has been 

 — ^needless to say — coterminous with his whole 

 existence. Science may explain that experience, 

 but is unlikely, it might seem, to improve upon 

 experience as a guide. It may supply theory, but 

 where experience has been so great and so continu- 

 ous it seems unlikely that it could do much to guide 

 practice. This consideration, consciously or sub- 

 consciously, accounts, I think, for a widespread 

 feeling that the teachings of science about our food 

 supply are of academic interest only. 



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