Finally, it should be said that the low proteid metabolism on which these men were apparently maintaining body-weight was not associated with any increase of non-nitrogenous food. At no time did the fuel value of the daily food reach 3000 calories; in fact, about January 12 the average fuel value of the food was only a little over 2000 calories per day. FIRST NITROGEN BALANCE. Early in January, the body-weight of the men having become practically stationary and the proteid metabolism, as measured by the output of metabolized nitrogen, having been reduced to a low level, an attempt was made to see if the men were truly in a condition of nitrogenous equilibrium. A six-day period was used, during which all the food for each meal was carefully analyzed, the nitrogen in every sample of food being determined in duplicate by the Kjeldahl-Gunning process. The fæces of the period were separated by lampblack, given at appropriate times in gelatin capsules, and all necessary precautions observed to insure an accurate nitrogen balance. The accompanying tables of results give all the necessary data. The average nitrogen intake per day was 8.23 grams, and the average fuel value of the food per day was 2078 calories. These are the figures for Oakman. With some of the other men there were slight variations from these figures, as shown in the tables—owing to slight variations in diet. Without exception, all the men showed a minus balance, indicating that on this diet the body was losing nitrogen. In other words, the diet as a whole was insufficient for the needs of the body in every case. Whether this was due to lack of sufficient proteid or to an insufficient amount of fat and carbohydrate, _i. e._, a too low fuel value, cannot be said definitely, but there is every reason to believe that the amount of non-nitrogenous food was insufficient to furnish the requisite fuel value, and consequently body proteid was drawn upon to supply the deficiency. The loss of nitrogen to the body per day varied as a rule from 0.5 to 2.0 grams. In one case only, viz., Broyles, was there a close approach to a balance. In his case there was a minus balance of only 0.12 gram of nitrogen per day. The average daily output of nitrogen through the urine for this six-days period (Oakman’s case) was 7.52 grams. [Illustration: FRITZ _Photograph taken at the close of the experiment._] OAKMAN. _Tuesday, January 12, 1904._ Breakfast.—Fried Indian-meal 100 grams, syrup 50 grams, one cup coffee 350 grams, bread 50 grams, butter 15 grams. Dinner.—Boiled macaroni 250 grams, stewed tomato 250 grams, bread 75 grams, one cup coffee 350 grams. Supper.—Potato chips 100 grams, fried bacon 25 grams, bread 75 grams, jam 75 grams, one cup tea 350 grams. Food. Grams. Per cent Nitrogen. Total Nitrogen.