THE FOOD AS A SOURCE OF ENERGY. 309 
As in the case of the ether extract of hay, the energy of the 
digested fat is less than that of the original material, which was 
9.478 Cals. per gram. 
Protein or WHeat GLuTEN.—Comparing the experiments with 
and without this material exactly as in the case of the starch, we 
have the following results * for the energy of the digested protein: 
-Ox B (Period 1)...............00.. 5.728 Cals. 
Ox B (Period 3)...............0c0s 5.817“ 
Ox C (Period 8............... 0000. 5.712 “ 
Ox D (Period 4)..............0.005 6.040 “ 
Ox E (Period 4)................... 6.009 ‘ 
Ox III (Period 3).................... 6.166 “ 
Ox III (Period 4).... .............. 6.277 
Ox IV (Period 3).............. -»... 6.061 “ 
AVEDALG: ech ieidadawncueeweiee 5.976 “ 
In these trials three different kinds of gluten were used which 
were prepared by somewhat different processes. The averages for 
the three sorts separately were as follows: 
NOs yds died cove Meebo bee Be 5.732 Cals. 
Re Davadics cuivds vee Wasa Seaton e Oulooo 
BO cclesrea a icace naar denianeheite na 6.168“ 
5.975 
The above figures refer to the so-called crude protein, that is, to 
nitrogen X 6.25. The proteins of wheat, however, contain con- 
siderably over 16 per cent. of nitrogen. Using Ritthausen’s factor, 
namely, 5.7, for the computation of protein from nitrogen reduces 
the amount of protein in the gluten and increases that of the 
nitrogen-free extract by the same amount. The energy of the 
digested protein when computed on this basis equals 6.148 Cals. 
per gram. 
Orcanic Matter of Coarse ‘Fopprrs.—For the total digested 
organic matter of hay and straw the following heat values per gram 
were computed: * 
* Loc, cit., 58, 412 and 414. 
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