350 HUMAN PHYSIOLOGY 



however markedly one type may predominate. It does 

 not appear that this argument should be given much 

 weight, for we use sugar chiefly as an addition to other 

 foods, but we can appreciate the suggestion that we 

 are not yet wise enough to know just what list of com- 

 pounds must be furnished for all the purposes of nutri- 

 tion and which ones can be omitted. In default of 

 complete information we ought to include as many as 

 convenient. 



Certain agitators contend that the best diet is one 

 composed entirely of uncooked foods. It is doubtful 

 whether a scientific foundation for such claims has 

 ever been conscientiously sought. We may conceive 

 that there are valuable bodies, perhaps deserving to be 

 called vitamins, which are destroyed by heat of the 

 degree used in cooking. In view of this possibility it 

 may be conceded that we should eat a good deal of raw 

 food. But the advantages of cooking in developing 

 flavors, increasing the digestibility of many articles, 

 and, above all, in sterilizing food which might be infected 

 cannot lightly be set aside. 



As it is possible that we may reject needed supplies 

 by too much refining of our food and lose something of 

 utility in the processes of cooking, so we may possibly 

 lose vitamins when food is preserved too long. When 

 we say that a canned product has lost its " goodness" 

 we are apt to refer to flavor, but it is not unlikely that 

 the gradual deterioration that goes on even in sterile 

 food may rob it of some of its nutritive worth. But 

 here again we may point out that a food which is not 

 perfectly adapted to meet all the current needs may still 

 minister to many of them and take its place helpfully 

 in the diet. It cannot be condemned as poisonous 

 merely because it has its limitations. 



It is evidently much harder to compare one diet with 

 another than has been commonly assumed in the past. 

 Some of our American physiologists have reported the 

 excellent results they have obtained with rations con- 



