




AVAILABILITY AND FUEL VALUE OF FOOD MATERIALS. 87 
calculated; the corresponding figures for the fats were 95.0 
against 94.5, and for carbohydrates 97.7 against 98.1. ‘These 
agreements seem to us to be reasonably close. 
Table 5 gives a summary of the calculated availability of 
the different nutrients in 93 digestion experiments with the 
coefhicients found by actual experiment. 
TABLE 5. 
Summary of comparison of coefficients of availability as found by 
actual experiment and as calculated by the proposed factors 
for avatlability. 










gel | | | CARBOHY- 
e PROTEIN. | FAT. ean ace 
gd | 
ry Y.. 3 “ | : 
& op : Sees o re ats 
aS EXPERIMENTS. ¢ =) Z = rd = 
| iS) | ie) 
S| Hiatt IO Pah eidbed 
Zi 1S) o) Pe 
At Middletown, Conn. Fp ee ae IE 
6 Metabolism experiments (1), 1896-7, | 93.2 | 92.2 90.7 | 94.7 | 98.4 | 97-5 
12 Preliminary to metabolism experi- | 
| ment (1), 1898-9, -. - - | 92.5 | 93.3 | 93-7 | 94-3 | 97-7 | 97-9 
14 | Metabolism experiments (1), 1898-9, | 93.9 | 93-5 | 94.8 | 94.3 | 97-9 98.0 
At Knoxville, Tenn. | | 
g Digestion and metabolism experi- | | 
| ments (2),. 1896-7, - =49320. 193-8.) G4: G''O4-0-) O72: Os.t 
23 Digestion and metabolism experi- | 
| ments (2), 1897-8, - = 19424.) 93.8 | 96.2 1:94.6'|07.4 | 98.2 
24 | Digestion and metabolism experi- | | 
| ments (2), 1898-9,  - - | 92.3 | 94.0 | 94.9 | 94.4 | 97.8 | 98.3 
5 Miscellaneous experiments (3), SEO ESO NG2, 290 3201 O4.5 =) 0720 4 O 7-4 
93 | Average of all above experiments, - | 93.3 | 98.6 95.0 | 94.5 | 97.7 | 98.1 


(1) -With men in respiration calorimeter. 
(2) With men at work and without active muscular work. 
(3) With men, Minneapolis, Minn., Knoxville, Tenn., and Middletown, Conn. 
It may be that these figures by themselves give an exagger- 
ated idea of the accuracy and value of such computations. 
‘There is more or less guess work in the method of estimating 
the coefficients of availability. It may be largely a matter of 
coincidence that these particular figures bring results agreeing 
so closely with those of actual experiment. It may be, for 
instance, that some of the coefficients of availability of indi- 
vidual nutrients of the different kinds of food materials are 
really wide of the mark and that the agreements which are so 
