956 NUTRITION AND HEAT REGULATION. 



balanced or maladjusted are indicated by McCollum* as follows: 



1. An inadequate supply of the necessary inorganic constituents. 



2. Inadequate amounts of protein, or the use of proteins of poor 

 quality, that is to say, of proteins not containing all the necessary 

 amino-acids. 3. A lack or deficiency in one or both of the acces- 

 sories, fat-soluble A and water-soluble B. 4. In some cases the 

 presence of toxic substances in certain foods, e. g., cotton-seed 

 products. It is obvious that along these lines there is much to be 

 learned and we can hope to acquire the necessary knowledge only 

 through laborious experimental inquiries. 



* McCollum, Harvey Lecture, "Jour. Amer. Med. Assoc.," May 12, 

 1917. 



