30 PHYSIOLOGY AND NATIONAL NEEDS 



they are normally consumed. This, I would repeat, 

 is one essential fact in connexion with what we 

 have agreed to call accessory food substances or 

 ' ' vitamines. ' ' Their influence on the body is great : 

 their amount as they exist in natural foods is appar- 

 ently exceedingly small. This is one reason why 

 they have for so long eluded recognition. 



Before putting further details before you I will 

 illustrate how great may be the importance to the 

 body of very small amounts of a nutritional factor 

 by reminding you of what still remains the most 

 vivid instance of the phenomena we are concerned 

 with. 



In certain rice-eating communities of the East, 

 in Japan, the Malay Peninsula, the Dutch Indies, 

 the Philippines, etc. where, owing to various cir- 

 cumstances, the diet is more exclusively confined 

 to the single cereal than is the case in the wheat- 

 eating West, the very serious disease beri-beri is 

 endemic. It is natural for pathologists to look for 

 a positive, rather than what may be called negative, 

 causation in disease, and after the development 

 of modern bacteriology many unsuccessful efforts 

 were made to find a microbic origin for beri-beri. 

 Long before this, it is true, the view had been held 

 that diet played a part in its production and the use 

 of rice was blamed. But the view taken was that 

 the cause was bad rice, rice infected with moulds 

 or other organisms. Only slowly did the under- 



