It is necessary at this time to point out an error made recently by us in a preliminary report of this research before the National Academy of Sciences in Washington, D. C. In this report it was stated that "the nitrogen output per day at the maintenance diet of 2,300 net calories was about 9 grams. A control group of 12 men, living substantially the same life and eating in the same dining-room, but with unrestricted diet, showed a nitrogen output of 16 to 17 grams per day."1 Three serious errors appeared in this statement:

(1) The caloric intake at the lowest weight level was not 2,300 calories, but 1,950 calories.

(2) An examination of the nitrogen balance tables (tables 46 to 58) shows clearly that the value of 9 grams for the nitrogen excretion at the lowest level of weight maintenance (December 3 to February 3) is too small, and that it should be 10.5 grams (see table 73). While one subject, Tom, excreted only 7.7 grams, another subject, Can, excreted invariably over 11 grams (see table 35) and averaged 12.0 grams.

(3) The statement that a control group of 12 men excreted from 16 to 17 grams is erroneous in that these figures represent not the nitrogen excretion but the nitrogen of the food. By reference to table 32 it can be seen that the nitrogen intake of a control group of 12 men ranged in 5 days from 17.06 to 20.80 grams, with an average of 18.46 grams. As has already been stated, our information regarding the normal excretion of nitrogen of our subjects is unfortunately scanty, but table 45 shows that the nitrogen excretion of a group of men on February 11 to 16, 1918, with normal unrestricted diet, averaged 13.97 grams.

1 Benedict and Roth. Proc Nat. Acmd. Sci., 1918, 4. p. 151.

Table 73. - Average Daily Nitrogen Excretion At Low Weight-Level - Squad A