298 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



being on the average 87 per cent. The agreement among the men 

 was remarkably constant, the widest variation being from 86 to 89 

 per cent. These men used on the average 25 grams of bran per day. 

 The uniformity of the figures, both for nitrogen and energy, indicate 

 that with a group of 12 men the same amount of food passing through 

 12 different digestive tracts results in a strikingly uniform degree of 

 absorption, even when an extraordinarily low diet is being taken. 



URINE. 



The collection of the entire 24-hour amount of urine from 12 or more 

 subjects for a period of several months was for the most part very suc- 

 cessfully carried out for Squad A, with the kind cooperation of these 

 men. We have full data for these specimens of the volume, specific 

 gravity, and total nitrogen. Obviously the most important factor is 

 the total nitrogen. The nitrogen data appear in several places in this 

 report, but it hardly seems justifiable to print the entire records of 

 the specific gravity and the volume. We content ourselves, therefore, 

 with giving a typical specimen of the urine records. (See table 39.) This 

 shows the statistics for Gul, who collected the urine for almost every day 

 of the entire experimental period, i. e., September 27, 1917, to Febru- 

 ary 2, 1918. Since this subject remained at Springfield throughout 

 the Christmas vacation, the records also include these days. 



STATISTICAL RECORDS OF URINE FOR SQUAD A. 



The influence of restricted diet upon the volume of urine is typically 

 shown in table 39. With Bro, Can, Gar, Gul, Mon, Pea, Pec, and Vea, the 

 volume of urine was materially reduced as a result of the restricted 

 diet, but with Kon, Moy, and Spe no effect on the volume of urine was 

 noted. With a single subject {Tom) there was a distinct tendency 

 for the volume of urine to increase, but it did not exceed the normal 

 limits. Occasionally very low volumes were found as, for example, 

 those with Gul, on January 17-18, 18-19, and 20-21. The largest 

 volumes were consistently voided by Can, who had the largest body 

 weight and who made a practice of drinking unusually large amounts 

 of water. Even in his case, however, the volume did not exceed the 

 normal amount. 



The specific gravity has only a secondary interest in that it gives 

 a rough indication of the amount of total solids, and incidentally, the 

 amount of total nitrogen. With many of the subjects the specific 

 gravity tended to increase, this being true of Bro, Gul, Mon, Pea, 

 Pec, and Vea. With Can, Kon, Gar, Moy, and Tom no consistent 

 change in the specific gravity was observed. With Sjpe there was a 

 tendency for the specific gravity to become reduced. The general 

 picture is that outlined in table 39 which indicates a tendency for the 

 specific gravity to increase with the reduction in diet. 



