46 PHYSIOLOGY AND NATIONAL NEEDS 



limited communities it is said to have followed the 

 use of white bread. The wheat grain, no less than 

 the rice grain, shows that an essential nutritive 

 factor may have an unequal and limited distribution 

 in a natural product, and illustrates the danger of 

 '* fractionating " natural foods to which I referred 

 in my opening remarks. 



It is clear that the danger of any deficiency in 



bread becomes the greater the more it bulks as a 



constituent of the whole diet. In the case of the 



poor — and especially the children of the poor — it 



undoubtedly bulks largely. Consider, again, the 



question of margarine as a substitute for butter. 



If the margarine is made wholly of vegetable fats 



it lacks the fat-soluble vitamine. It is not by any 



means so trivial a point as it may seem to remember 



I that brown bread and butter is, from the standpoint 



/ of vitamine supply, an excellent combination, while 



white bread and margarine may be a desperately 



bad one. 



[Speaking in parenthesis, I happen to be aware 

 from personal knowledge that the margarine indus- 

 try in this country is quite alive to the significance 

 of the facts. Given full liberty of action the trade 

 is, I believe, both willing and able to turn out pro- 

 ducts lacking the reproach of this deficiency.] 



We must remember, again, that polished rice 

 contributes not a little to the table of the poor, 

 especially in some districts, and is often eaten plain 



