
DIGESTIBILITY OF FISH AND POULTRY. 129 
determined by the bomb calorimeter was the same as the ratio 
of the calculated energy of the feces from food other than fish 
or poultry to the required value. 
Thus, in experiment No. 598, the computed energy of the 
total feces was 264 calories and the energy as determined from 
the heat of combustion 303 calories. The calculated value 
for the feces from food other than salmon was 192 calories. The 
proportion was therefore 264 : 303 — 192: x, in which case 
=) =—4220 Calories. 
The energy of the feces from salmon alone, 83 calories, was 
found by subtracting this figure from 303 calories. The pro- 
portion of energy in the salmon alone which was actually avail- 
able to the body was then computed as in previous work by 
assuming that the energy lost to the body was equal to 1.25 
times the weight of protein digested from the salmon alone 
(237.2 grams) or 297 calories. This amount, plus the 83 
calories lost in the feces, subtracted from the total energy of 
the salmon (2793 calories), divided by 2793 calories and mul- 
tiplied by 100, gave 86.39 per cent. the coefficient of availa- 
bility of the energy of the salmon alone. 
In the following pages the data of the four series of experi- 
ments are presented in detail. 
EXPERIMENTS WITH SALMON. 
The first series of experiments began with breakfast, Feb. 
12, and continued three days with nine meals. The food 
under investigation was canned salmon, selected as a type of 
fish containing considerable fat. The remainder of the diet 
included bread, milk, butter, and sugar, though H. C. M. 
omitted milk, and E. M. S. butter from several of their meals. 
The data of the four experiments with salmon are given in 
Table 14. 
EXPERIMENTS WITH COD. 
As a type of fish containing relatively little fat, fresh cod 
steaks were selected. The remainder of the diet included 
bread, milk, butter and sugar. One of the subjects, H. C. M., 
consumed no milk during the entire experiment, and the others 
omitted butter or sugar from one or more meals. R. D. M. 
consumed no cod at dinner and supper of the third day. 
