320 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Table XXXV. — Weight, composition, and heat of combustion of feces — Metabolism experiments Nos. 18-81. 



In these investigations the elimination of nitrogen in the urine on the first day inside the 

 apparatus has frequently been larger than that of the preceding and following days. Sometimes 

 this increase occurs 1 or 2 days before the subject enters the respiration chamber. On the 4 days 

 of the preliminary period preceding this series of experiments the nitrogen in the urine amounted 

 to 12.2, 16, 19 and ltj.4 grams, respectively On the first day of experiment No. 18 the nitrogen 

 in the urine amounted to 17.4 grams, but it dropped to 15.4 grams on the second day, and varied 

 between 13.9 and 14.7 on subsequent days. In experiment No. 21, when the energy of the diet 

 was reduced, the excretion of nitrogen again increased. The elimination of nitrogen with and 

 without alcohol has been already referred to. 



Table XXXVI gives the detailed statistics of the quantity of urine and its nitrogen content 

 in the successive H-hour periods of this series of experiments. The statistics for experiment No. 

 21, in which no alcohol was given, show the total quantity of urine and nitrogen for the 

 individual days, but not for individual periods. These daily amounts are given for the sake of 

 comparison with those of experiments 18-20. 



Table XXXVI. — Amount, specific gravity, and nitrogen of urini by 6-hour \>< riods — Metabolism experimi nts Nos. IS— SO. a 



'No. -'1 included for comparison. 



