118 STORRS AGRICULTURAL EXPERIMENT STATION. 
combustion determined. From the data thus obtained, the 
availability of the diet as a whole and of the fgsh or poultry 
alone was calculated as explained more fully beyond. The 
details of the separate experiments follow. . 
Subjects. —The subjects of the sixteen experiments were four 
men ranging from 19 to 38 years of age and from 60 to 75 
kilograms in weight. All were engaged in light work in con- 
nection with the nutrition investigations. ach one took some 
physical exercise each day, the total daily amount of muscular 
activity being probably on the average about equivalent to that 
of a man at light muscular work. No attempt was made, how- 
ever, to secure uniformity. The men simply pursued their 
ordinary course of life except as regards diet. 
All the subjects were in good physical condition, with ap- 
parently normal digestion. Two of them, EK. O. and R. D. M., 
had previously been subjects of digestion experiments, and the 
other two, from their experience in the laboratory, fully under- 
stood the nature and requirements of such experiments. - _ 
Duration.—In digestion experiments, as long periods as 
practicable are desirable, since thereby any error, as in the 
separation of the feces pertaining to the digestion period, would 
be mimimized. In these experiments the period was in each 
case three full days. . 
Diet.—In these experiments the diet consisted of the food 
under investigation, together with bread, sugar, milk, butter, 
and in some experiments duck-fat and rock-candy. No restric- 
tion was placed upon the amount of any food material to be 
eaten, each subject choosing what seemed to him to be sufh- 
cient to satisfy his needs. Some of the subjects endeavored to 
secure uniformity from meal to meal of at least a portion of 
the diet. 
In order to compute the availability of the fish and poultry 
alone, as hereafter explained, the diet was purposely made as 
simple as possible consistent with palatability. ‘Theoretically, 
an ideal diet for such experiments would consist of only the 
material studied; but such a diet, as pointed out in a previous 
report,* would not be practicable, and it is believed that results 
obtained by the methods here reported indicate more closely 
~ 
* Storrs Expt. Sta, Rpt. 1904, p. 183. 
