DIGESTIBILITY OF WHEAT BRAN. 9 
sisted of a bran bread as the principal food, with enough accessory 
foods to make the diet tolerable and reasonably palatable, namely, 
boiled and mashed Irish potatoes (in limited quantities) , fruit, butter, 
sugar, and tea or coffee. 
The bran bread was prepared daily. A sufficient quantity of po- 
tatoes to supply all the subjects for the entire test period was boiled, 
mashed, and uniformly mixed at the beginning of the period. The 
fruit (oranges), butter, and sugar were purchased in the open mar- 
ket. The bran bread was made by the following recipe, which as 
will be noted contains some ginger and molasses. These materials 
were added primarily to make the bran more palatable and to mask 
its nature somewhat. 
BRAN BREAD. 
15 cups bran. 32 teaspoons salt. 
32 teaspoons soda. 5 teaspoons ginger. 
12 cups molasses. 1 secant cup lard. 
1% quarts hot water. 
The lard was added to the hot water and the mixture added to the 
other ingredients, after which the whole was uniformly mixed. The 
bread was baked about 14 hours. Since the bran contained no glutin- 
ous material to serve as a binder, the bread did not rise well and 
tended to crumble. 
The digestibility of the protein and carbohydrate of the bran 
alone has been estimated by making allowance for the undigested 
protein and carbohydrate resulting from the accessery foods. In 
estimating the digestibility of bran alone by the method which has 
been outlined in full in earlier publications? it has been assumed, as 
a result of averaging the results of earlier experimental data, that 
the digestibility of the accessory foods is as follows: The protein 
of potatoes, 83 per cent’; of butter, 97 per cent ?; and of fruit, 85 per 
cent”; while the digestibility of carbohydrate in potatoes, fruit, and 
sugar, is 95 per cent,? 90 per cent,” and 98 per cent,” respectively. 
The details of the digestion experiments are recorded in the fol- 
lowing tables, which include the kind, amount, and total weight of 
different foods eaten by each subject, the weight of the various con- 
stituents of the foods, the weight of the feces, the amount of food 
utilized, the coefficients of digestibility of the entire ration, and the 
estimated digestibility of the bread alone. 
EXPERIMENTS WITH FINE WHEAT BRAN. 
While the seven experiments which were made with fine bran were 
not all carried on at the same time, the subjects and experimental 
1U. 8. Dept. Agr. Buls, 470 (1916), p. 7; 525 (1917), p. 4. 
2 Connecticut Storrs Sta. Rpt. 1899, p. 104. 
85781°—19—Bull. 751 
2 
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