DIGESTIBILITY OF SOME ANIMAL FATS. 
17 
ments here reported. For convenience it was served in the form of a 
fish loaf rather than incorporated in a cornstarch blancmange, such 
as was used with the other fats. With the fish loaf a simple basal 
ration was served which consisted of potato (boiled and mashed) and 
biscuits or crackers, fruit (raw apples), and sugar with tea or coffee 
when such beverages were preferred to water. A small amount of 
lemon juice was used with the fish as a condiment, but no account 
was taken of it in computing the nutritive value of the ration. 
The fish loaf was prepared as follows: Boston mackerel (a typical 
fat fish), weighing when cleaned approximately 3 pounds each, were 
washed and cooked in a covered pan for half an hour in a moderate 
oven, a little water being added so that the fish would not stick to the 
pan. The bones, skin, etc., were then removed and the fish flesh 
minced in an ordinary household meat cutter. The small amount of 
liquid which remained in the pan was mixed with the minced fish 
to avoid the loss of any fat which had " cooked out." After season- 
ing moderately with salt and pepper, the minced fish was formed into 
a loaf and baked two or three hours in a moderate oven. The crusty 
surface was removed and the inside portion of the loaf was thoroughly 
mixed and divided into suitable quantities for the subjects' meals. 
Though different in form, the diet was similar in nutritive value to 
those in the other experiments here reported, fish protein replacing 
the protein of the skim milk used in making the cornstarch blanc- 
mange and mashed potato replacing the cornstarch. That the diets 
were directly comparable in nutritive value is evident from a com- 
parison of the protein, fat, and energy which the subjects obtained 
per day from each. 
The details of the three experiments which were made follow. 
Data of digestion experiments with Boston mackerel in a simple mixed diet. 
■ Weight. 
Water. 
Pro- 
tein. 
Fat. 
Carbo- 
hydrates. 
Ash. 
Experiment No. 444, subject D. G. G.: 
Boston mackerel (in form of fish loaf) 
Grams. 
1, 496. 
439.0 
284.0 
1, 320. 
171.0 
Grams. 
926.0 
331.5 
19.6 
1, 116. 7 
Grams. 
323.0 
11.0 
23.0 
5.3 
Grams. 
199.9 
.4 
38.0 
6.6 
Grams. 
Grams. 
47.1 
Potato 
Crackers 
91.7 
201.1 
187.4 
171.0 
4.4 
2.3 
Fruit 
4.0 
3,710.0 
67.0 
2, 393. 8 
362.3 
19.3 
343.0 
244.9 
10.1 
234.8 
651. 2 
31.9 
619.3 
57.8 
Feces 
5.7 
52.1 
94.7 
95.9 
95.1 
90.1 
Experiment No. 446, subject R. L. S.: 
Boston mackerel (in form of fish loaf) 
Potato 
1, 184. 
227.0 
243.0 
1,376.0 
58.0 
732.9 
171.4 
16.8 
1,164.1 
255.6 
5.7 
19.7 
5.5 
158.2 
.2 
32.6 
6.9 
37.3 
47.4 
172.-0 
195. 4 
58.0 
2.3 
1.9 
Fruit : 
4.1 
Sugar 
3, OSS. 
53.0 
2, 085. 2 
286.5 
21.9 
264.6 
197.9 
7.5 
190.4 
472.8 
16.2 
456.6 
45.6 
7.4 
38.2 
92.4 
96.2 
96. 6 
83.8 
