154 STORRS AGRICULTURAL EXPERIMENT STATION. 
EXPERIMENTS ON THE DIGESTION OF FOOD BY 
MAN. 
REPORTED BY W. O. ATWATER AND F. G. BENEDICT. 

The observations here reported are in continuation of those 
described in the previous reports of the Station, and especially 
in the Report for 1896, pages 163-180. They belong to a 
series of metabolism experiments with the respiration calori- 
meter, described beyond, in which the income and outgo of 
the body of man was measured. ‘These metabolism experi- 
ments usually continued for a period of eight days, and were 
divided into two periods of four days each, the food being 
uniform during the eight days. The kinds and amounts of 
food were in general such as had been previously found to suf- 
fice the needs of the subject. 
The first period was preliminary, the object being to bring 
the body into approximate equilibrium with the food. <A rea- 
sonably close approximation to nitrogen equilibrium was gen- 
erally reached at the end of the first period, as was shown by 
comparison of the nitrogen in food, feces, and urine. During 
this preliminary period the subject was generally in the labora- 
tory or at his home, but the effort was made to have his mus- 
cular activity similar in amount to that of the second: period. 
In experiment No. 37 the preliminary period was eight and in 
No. 39 it was five days instead of four. During the second 
period, which continued four days and five nights, the subject 
was in the chamber of the respiration calorimeter, and the 
nitrogen, carbon, hydrogen and energy of income and outgo 
were determined. . 
Sudject.—All of the experiments were made with the same 
person, a laboratory assistant, a man in good health, thirty 
years of age, and weighing not far from 147 pounds without 
clothing. i | 
Methods.—The general plan of the experiments was the same 
as previously described.* The methods of analysis were those 
Report of this Station for 1896, page 163. See also Bulletin 21 of the Office of 
Experiment Stations, U. S. Department of Agriculture, on Methods and Results of 
Investigations on the Chemistry and Economy of Food, pages 57-60. 

