e 
202 STORRS AGRICULTURAL EXPERIMENT STATION. 
differ considerably in digestibility. But experimental data at 
hand are not sufficient to show what these differences are. 
Experiments upon this subject are now being carried on, how- 
ever, under the auspices of the Office of Experiment Stations, 
and it is hoped that the needed information may be gradually 
acquired. 
Fuel values.—In the following table the fuel values of the 
digested nutrients were calculated by the use of the factors 
proposed by Rubner and now ordinarily accepted as explained 
on page 177. The factor 4.1 as used for the fuel value of one 
gram of protein is evidently too small. Indeed, all the factors 
need revision to fit them to different food materials and condi- 
tions of use. It is hoped that results of investigations upon 
the subject now in progress in this laboratory may be published 
in the near future. Meanwhile the common factors are used 
in these calculations, but with the understanding that they 
will doubtless be changed later. 
‘TABLE .61-. 
Estimates of proportions of digestible and undigestible nutrients 
in food materials. In these calculations it?s assumed that the follow- 

















ng percentages are digestible: Carbo- Mineral 
Protein. Fat. hydrates. Matters. 
Animal foods, - = - - 98% 97 & ICO % 75 % 
Cereals and sugars, - - - 85% gO % 98 % 75 % 
Vegetables and fruits, - - 80% go cm 95 % 75 % 
wets Boeoues Rey ¥ 
Dy Nutrients. Sees 
z Di ib] 5S 
Foop MATERIALS. = = patina = a4 
Bile a con eee esis ok 
Pole | (ee) e eae 
Ay O>|=s 5 A 
ANIMAL Foon, pol A ay sad ae ob | Oe er 
Beef. 
Edible’ portion; ——"16 8.6/12 a 
anita i § p 7.4118.6|12.2 7h Tt SiGe 
Chuck, ~{ As purchased, |16.8/56.1/15.5|10,2| — | .6| 8 q15 
ne : § Edible portion,| — |60.5|17.8 1007 .8) 1.2/1165 
: "7 As purchased, /13.1|52.5|15.6]17.1| — .7| I.O|1OLO 
ea ok 5 _§ Edible portion,| — |63.4|18.8/16.0) — .7| I. 1/1025 
: pas purehased; /27-6145)0113-6.7 bh. 5) == 5) ,Ol ere 
Ribs 4 é _§ Edible portion,) — |55.5 16.7\25.8| — 7) ts 3) tae 
’ ~ ( As purchased, (20.8/43.8 13.2}20.6) — 5] Torte 
eae eon eee portion,| — |65.5/19.4/13.2| — 8). 5,1) .om 
, As purchased, | 7.2/60.7 I7.9!12.4! — .o| I, 0}-Ba5 

