URINE. 305 



of the variations found between individuals and between the results for 

 the same individual from day to day. Of greater importance, however, 

 is the picture presented by the squad as a whole. This is shown in 

 table 44, in which is recorded the total nitrogen in the food and in the 

 urine for the entire series, expressed as the average per man per day, 

 for Squad A. An examination of the nitrogen in the urine shows, on 

 the whole, a constant nitrogen output. It is rarely that differences 

 of more than 2 grams are noted from day to day. Values less than 10 

 grams do not appear until November 9-10. An absolute minimum 

 of 7.90 grams is noted on January 15-16. There is no clear picture of 

 a definite appreciable reduction in the nitrogen output per man per 

 day until approximately the middle of January, but in the latter part 

 of January low figures appear with considerable frequency. In 

 general one may state that in spite of the great alterations in the diet 

 made with these men, the nitrogen excretion on the average was but 

 little affected. If we average the low-diet values by months, we 

 would find that the average excretion for the month of October would 

 be 11.47 grams, for the month of November 10.60 grams, for the 3 

 weeks in December 10.87 grams, and for the month of January 10.34 

 grams. 



The most unportant aim in the reduction of diet was to secure a 

 decrease in caloric content and no attempt was made to secure an 

 especially low level of protein. In fact, in certain instances, at least, 

 the protein was measurably increased, since it was found that the low 

 diet was resulting in a somewhat heavy draft upon body nitrogen. 

 The nitrogen intake is also shown in table 44. After the first 3 days in 

 October, the reduction in diet with special reference to the caloric 

 content began. The irregularities of the nitrogen intake, as pointed 

 out in the discussion of the two periods in tables 40 and 42, are 

 likewise found throughout the entire period, practically no two days 

 being alike. Occasionally, the variations are somewhat large as, for 

 example, from October 17-18 to October 18-19, when there was an 

 increase of nearly 4.5 grams. This again illustrates the fact that the 

 protein was not controlled. 'With such variations in nitrogen intake, 

 and particularly with the low nitrogen intake during a considerable 

 period of the time, it is surprising that the urinary nitrogen was not 

 more affected. Thus, for a period from October 31 to November 12, 

 inclusive, the daily values for the nitrogen intake are all less than 10 

 grams; in fact most of them are less than 9 grams. Yet the nitrogen 

 excretion in the urine remained at a fairly high level throughout the 

 entire time, this being, of course, positive proof of a loss on the part 

 of the squad as a whole of a considerable amount of body nitrogen. ^ 



The most important fact to be drawn from this table, therefore, is 

 that in spite of material reductions in food nitrogen and relatively 

 large variations in the intake of nitrogen, the urinary nitrogen output 



