THE UTILIZATION OF ENERGY. 531 
Experiments of 1877-1886.—During the years named, in addi- 
tion to the preliminary investigations necessary in working out the 
method, a large number of experiments were made on three different 
animals. The rations consisted largely of hay and oats in some- 
what varied proportions, together with smaller amounts of other 
feeding-stuffs. In three experiments on starch and four on oats a 
comparison of the increase in digested nutrients * with the in- 
creased work which could be done gave the following results: + 
Increase in Digested] |Increase in Work Done} Nutrients Equivalent 
Nutrients, at 76 Kg. Draft, to 100 Revolutions, 
Grms. : Revolutions. Grms. 
Starch.......... 677.3 217 312 
Oats .esccsee des 577.0 175 318 
AVEGPARO sc 552 cornea te aan sot cate eased 315 
Tur MaINTENANCE REQUIREMENT.—As already stated, it was 
discovered later that the dynamometer used was unreliable and 
gave too high readings, so that the above result cannot be em- 
ployed to compute the utilization of the energy of the added food. 
It does, however, in its present form, enable us to compute the 
maintenance requirements of the horse by subtracting from the 
total digested food the nutrients equivalent to the work performed 
(i.e., 3.15 grams the number of revolutions). The results of such 
a computation made by Wolff t are given on p. 532. 
The actual live weights in these experiments were somewhat 
below the normal weights, which were regarded as being about 
533 kes. for No. I, 500 kgs. for No. II, and 475 kgs. for No. IL. 
Wolff considers the maintenance requirements to be independent 
of minor changes in weight, and on the basis of the above “normal” 
weights computes the maintenance requirements per 500 kgs. live 
weight as follows: 
Forse Diss crete sea a on RSE ea re grams 
EO Tlie ataeaat a Aesth a raat naan Spatial eee Soc e 
Mo TD ein saaicee oes gener oes eae 4167“ 
Averages wrwascceaeeesioevacew ee 4190 “ 
* The algebraic sum of the differences in the single nutrients is used, and 
in this and the succeeding comparisons the digested fat is multiplied by 2.44. 
+ Loc. cit., pp. 125-129. 
t Loc cit., pp. 99 and 132. 
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