* From the Department of Biochemistry, University of Alberta, Edmonton.
This is the twelfth in the series of articles on Diet and Nutrition, prepared under the auspices of the Association's Committee on Nutrition. The previous articles can be found in the Journal, 1938, 38: 277, 387, 491. 586; 39: 76, 179, 280, 389, 483, 578; 40: 77.