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 successfully 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 February 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 Spe 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.

Table 39. - Statistics Of Urine For Gul, Squad A

1 Volumes represent mainly 24 hour samples; a number were computed to basis of 24 hours from samples covering 22 1/4 to 25 3/4 hours. In two instances the samples were for 21 1/2 and 26 hours respectively.

The total nitrogen excretion may first be considered simply as an index of the excretion of organic material. It can be seen from table 39 that with Gul the nitrogen excretion varied considerably from day to day. The maximum amount recorded for this subject on any day was 14.66 grams during the Christmas vacation; the minimum amount was the extraordinarily small quantity of 3.90 grams on December 1-2. In the beginning of the experiment there was considerable irregularity in the amount of nitrogen excreted, with a tendency for lower values to obtain subsequent to November 22. Yet there appears to be no definite correlation between the volume of urine, the specific gravity, and the total nitrogen excretion, nor do the other subjects show an approximation to regularity in such relationship. The nitrogen data for the other subjects will, however, be given in subsequent tables and discussed in that connection.

The general conclusion, therefore, which may be drawn from the urinary excretion of these subjects is that the reduced diet has a distinct tendency to lower somewhat the volume of urine and likewise a corresponding tendency to increase to some extent the specific gravity. This is more or less to be inferred from the fact that there was no profound alteration in the total amount of nitrogen excreted, and hence the smaller volume of urine was somewhat more concentrated. Little, if any, satisfactory discussion can be introduced here as to the fact that the lower volumes require somewhat less work of the kidneys, for it may be questioned whether or not the decrease in the work of excretion due to the smaller volumes would not in large part be compensated by the somewhat increased concentration of the urine. In any event the change is not sufficient to consider that this would have a material effect upon the general urinary output of these subjects, so far as specific gravity and the volume of urine are concerned.