106 STORRS AGRICULTURAL EXPERIMENT STATION. 
The data of these digestion experiments serve for making a 
comparison not only of the fuel values as computed and as 
actually found by experiment, but also of the total energy as 
computed and as actually determined. In making these com- 
putations the quantities of protein, fats, and carbohydrates 
furnished by the different nutrients consumed were multiplied 
by the corresponding factors for heats of combustion and for 
fuel values, and thus the total computed energy and fuel value 
of the diet was found. ‘The proportion which the calculated 
values bear to the corresponding values as actually determined 
was then computed. Thus in digestion experiment No. 37, 
1,165 grams of meat were consumed, furnishing 326 grams of 
protein and 69 grams of fat. The heat of combustion of the 
protein of meat was assumed to be 5.65 calories per gram and 
of fat 9.5 calories per gram. ‘The heat of combustion as cal- 
culated thus amounts to 2,497 calories (326 & 5.65 + 69 X Gas 
== 2,497). The fuel value of the 326 grams of protein and 69 
grams of fat was found by multiplying by the factors 4.25 and 
9.00 respectively, and amounts to 2,007 calories (326 * 4.25 
+ 69 X 9.0= 2,007). Ina similar manner the heat of com- 
bustion and fuel value of the other foods used were calculated. 
The total heat of combustion of the diet as calculated amounted 
to 21,763 calories, while the actual determination by means of 
the bomb calorimeter showed 21,467 calories. ‘The calculated 
value was thus ro1.4 per cent. of that actually determined. 
The fuel value of the diet as calculated amounted to 19,559 
calories, while the amount of energy actually made available 
in this experiment was 19,299 calories. The calculated fuel 
value was thus ror.4 per cent. of the fuel value actually found 
by experiment. 
The results of these comparisons are shown in Table rr on the 
following page. It is of considerable interest to note that in the 
twenty-seven experiments compared in this table the maximum 
variation between the heat of combustion as calculated and as 
found amounts to but 2.5 per cent. of the latter value, while the 
average values are identical. At the same time the fuel value 
as calculated ranges from 3.1 per cent. above to 2.1 per cent. 
below that actually found by experiment, the average differ- 
ence in twenty-seven experiments being but one part in a 
thousand. This close agreement between the computed values 

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