350 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



The irregularities in the nitrogen intake have been pointed out in a 

 previous section, as shown for the individual subjects at the beginning 

 of the observations and for 2 weeks in December and from the average 

 for the whole squad. These irregularities are strikingly shown in tables 

 46 to 58. The estimated intakes of nitrogen and energy for the un- 

 controlled days are also included in these tables, but are indicated 

 by footnotes, since their mathematical accuracy is in doubt. They 

 stand out prominently as the intakes of both nitrogen and calories 

 are larger than on either the preceding or following days. The gain 

 or loss of nitrogen for these uncontrolled days is not computed except 

 for January 13-14, 1918. The estimations for nitrogen intake are, 

 however, considered of sufficient accuracy to be included in any 

 general averages which appear in the tables. Unfortunately, owing 

 to the extremely cold winter and unsatisfactory transportation, some 

 of the samples of urine for December 15, 16, and 17 were frozen, and 

 hence the values for these days can not be given, and no estimate 

 has been attempted. These days are omitted from any general con- 

 sideration of the nitrogen balance. Although it was impossible to 

 obtain the fecal nitrogen for the entire period, reference to table 37 

 (p. 293), and, indeed, tables 46 to 58, shows that the separation of 

 feces was made with sufficient frequency to give a fairly uniform pic- 

 ture of the probable fecal nitrogen excretion for the whole experiment. 

 In the detailed tables the interpolated values are placed in parentheses, 

 all other values for feces being those actually determined. These 

 determined values usually represent the average for a period of col- 

 lection of feces of 3 to 16 days. 



The general picture presented by every member of Squad A is a 

 great predominance of minus figures for the nitrogen balance, after 

 the first three preliminary days of unrestricted diet. Plus values 

 rarely appear, except in the latter part of December and the latter 

 part of January. Throughout the period of loss in weight there was 

 evidently a pronounced tendency for each subject to lose nitrogen. 

 During December, when an attempt was made to supply a sufficient 

 number of calories to secure weight maintenance, the frequent appear- 

 ance of positive figures indicates that with the higher caloric intake 

 there was a smaller loss of nitrogen with a tendency towards equih- 

 brium. During the last week in January this is particularly notice- 

 able. A general statement may thus be made that for practically 

 the entire experiment, save for these two periods, the subjects were 

 losing body nitrogen, as shown by a comparison of the fecal and 

 urinary nitrogen with the nitrogen in the food. 



The total losses of nitrogen from the body shown by these men prior 

 to January 28 are of interest, since in the last week of the experiment 

 the caloric intake was considerably increased to hold the body-weight. 

 The total losses of nitrogen from October 4, the initial day of the re- 



