524 | PRINCIPLES OF ANIMAL NUTRITION. 
Ei K; 
Beooted ey net ork 
Respira- 
Predominant Nutrient. ie sa: |e | Be First | Segond | Third 
jient. 5 2 
Cals, | drates,| teids, | sump- | sump- | sump 
Cals. : cals. cals. cals. 
a a...| 0.783 | 3829 | 1379 | 163,| 10.98 |....... 10.35 
Met eeenees b....| 0.724 | 4422 } 2461 163° 9.39 | 0.85 | 9.27 
0.805 | 3414 | 1823 | 139 | 11.15 |.......] 10. 
Carbohydrates. {her ‘| 0.901 | 1543 | 3374 | 139 | 10.67 | 10.63 | 10.37 
As much proteids as 
possible........... 0.796 | 3381 | 1620 | 377 | 11.40 | 11.27 | 10.64 
The subject was not able to consume even approximately 
enough proteids to supply the demands for energy, so that the 
experiments are virtually a comparison of the utilization of fat and 
carbohydrates in different proportions. With the exception of the 
third group, the results seem to show that the energy of the fat 
metabolized was utilized, if anything, rather more fully than that 
of the carbohydrates. 
Frentzel & Reach experimented upon themselves, the work 
being done by walking in.a tread-power; otherwise the methods 
were similar to those of Heineman. In computing the results of 
the experiments on a carbohydrate and a fat diet they assume that 
there was no increase in the proteid metabolism as a consequence 
of the work. For the experiments on a proteid diet they com- 
pute the results both on this assumption and also on the assump- 
tion of a maximum participation of the proteids in work produc- 
tion. Calculated in this way the total evolution of energy per kilo- 
gram weight and meter traveled was as given in the table on p. 525. 
The results show a slight advantage on the side of the carbo- 
hydrates, which in the case of Frentzel is regarded by the authors 
as exceeding the errors of experiment. They compute, however, 
that it is far too small to afford any support to Chauveau’s theory. 
Zuntz* has recalculated Heineman’s results, using slightly 
different data but reaching substantially the same result. He 
shows, however, that they are affected by the influence of train- 
ing already discussed on p. 519. Arranging the experiments in 
chronological order, it becomes evident that the work was done 
* Arch, ges. Physiol., 88, 557. 
