PHYSIOLOGICAL ECONOMY IN NUTRITION. 127 



value of over 3,000 large calories, is a necessary requisite for bodily 

 vigor and physical and mental fitness? Mainly because of the sup- 

 position that true dietary standards may be learned by observing the 

 relative amounts of nutrients actually consumed by a large number 

 of individuals so situated that the choice of food is unrestricted. But 

 this does not constitute very sound evidence. It certainly is not above 

 criticism. We may well ask ourselves whether man has yet learned 

 wisdom with regard to himself, and whether his instincts or appe- 

 tites are to be entirely trusted as safe guides to follow in the matter 

 of his own nutrition. The experiments of Kumagawa, Siven and 

 other physiologists, have certainly shown that men may live and 

 thrive, for a time at least, on amounts of proteid per day equal to 

 only one half and one quarter the amount called for in the Voit 

 standard. Siven 's experiments, in particular, certainly indicate that 

 the human organism can maintain itself in nitrogenous equilibrium 

 with far smaller amounts of proteid in the diet than is ordinarily 

 taught, and further, that this condition can be attained without 

 unduly increasing the total calories of the food intake. Such investi- 

 gations, however, have always called forth critical comment from 

 writers on nutrition, indicating a reluctance to depart from the cur- 

 rent doctrines of the Voit or Munich school, and, indeed, it may 

 justly be claimed that the ordinary nutrition experiments, extending 

 over short periods of time, are not entirely adequate to prove the 

 effect of a given set of conditions when the latter are continued for 

 months or years. Thus, Schaf er writes : " It may be doubted whether 

 a diet which includes considerably less proteid than 100 grams for 

 the twenty-four hours could maintain a man of average size and 

 weight for an indefinite time. It has frequently been asserted that 

 many Asiatics consume a very much smaller proportion of proteid 

 than is the case with Europeans. The inhabitants of India, Japan 

 and China chiefly consume rice as the normal constituent of their 

 diet, which contains relatively little proteid; and this has been ad- 

 vanced as an argument in favor of the view that the minimal amount 

 of proteid is much less than that ordinarily given as essential to the 

 maintenance of nutritive equilibrium. It must, however, be stated 

 that we have no definite statistics to show that, in proportion to their 

 body-weight, Asiatics doing the same amount of work as Europeans 

 require a less amount of proteids; indeed such evidence as is forth- 

 coming is rather in favor of the opposite view." This statement is 

 typical of the attitude of physiologists in general on this important 

 subject. Why not candidly admit that the matter is in doubt, and 

 with a due recognition of the importance of the subject attempt to 

 ascertain the real truth of the matter? 



The writer has had in his laboratory for several months past a 

 gentleman (H. F.) who has for some five years, in pursuit of a study 



