

DIGESTION COEFFICIENTS OF FOOD MATERIALS. _ 189 
to assume that these coefficients represent fairly well the digestt- 
bility of the food materials when used in mixed diet and under 
such circumstances as those of these experiments. 
Coefficients of digestibility were taken from the results of other 
experiments and slightly modified and classified for the purpose 
of calculation. Applying these assumed coefficients to the food 
materials as used tn an actual experiment, the proportions of digest- 
2ble nutrients for that diet are readily calculated. 
The results as found by the experiments described above and 
those calculated by use of the assumed coefficients just referred to 
agree with remarkable closeness. Differences in the individual 
experiments range from zero toa maximum of four per cent. (in 
a single case), and are generally less than two per cent. In the 
averages of the experiments they are much smaller. The amount 
of this variation ts shown in the following summary: 
TABLE 59. 
Comparison of coefficients of digestibility as found by actual exper- 
zment wzth. those calculated as described above. 









: “oq 
g| B |$s84. 
ze | & |8-38 
85 2 Sea g 
COEFFICIENTS OF DIGESTIBILITY. ny 2, < peg eats 
ag | & |steyh 
a SS a Set: 3 
rQ <x a ql 
3 to ho fo 
6 experiments here reported (Nos. 6, 10-14),| 91.3 | 91.5 + .2 
Protein, g experiments by Prof. Wait (Nos. 20-28), | 94.0 | 94.6 + ..6 
Average of 15 experimentt, — - - =) 90.7-| 04.0 1° = xd 
6 experiments here reported (Nos. 6, 10-14),| 96.7 | 96.5 — .2 
Fats, g experiments by Prof. Wait (Nos. 20-28), | 94.4 | 96.1 + 1.7 
Average of 15 experiments, - = -| 95.3 | 96.3 +1.0 
6 experiments here reported (Nos. 6, 10-14),| 98.4 | 97.7 ey 
eno 9 experiments by Prof. Wait (Nos. 20-28), | 97.2 | 98.3 + 1.1 
hydrates, Average of 15 experiments, - PaO Teint. Don. + (4 

This close agreement implies that the assumed coefficients fairly 
represent the proportions of nutrients that are digested, under 
ordinary normal conditions, from such food materials as those 
used in these experiments. While they are not to be taken as an 
exact measure of the digestibility of every kind of food of a 
given class, nor, in every case as an exact measure of the average 
digestibility of the class as a whole, it seems probable that they do 
represent pretty fairly the average digestibility of these classes of 
food under ordinary circumstances. 
