THE RELATIONS OF METABOLISM TO FOOD-SUPPLY. 157 
Lost from Body. 
ae | aaa 
Experiment I: {77594 grams. thamsnose 2.0..0_] 21080 | 12/020 
Experiment 1: {1799 grins, shataose 1.2.22.) 1629 | 10°835 
Experiment IL: | 18°96 gems. thamuicse 12.2.../) 0.888 | 5.838 
Experiment IV: {oq"s9 grins thamnose 2000.01] 3:1a3 | 4.482 
The conditions in the first experiment were not regarded as 
satisfactory. In the other three the loss of fat from the body was 
notably diminished by the administration of rhamnose, precisely as 
in the experiments of Pettenkofer & Voit and of Rubner (pp. 147 
and 148) with the hexose carbohydrates. The quantitative results 
vary considerably in the individual experiments, but in the second 
and fourth correspond quite closely to the law of isodynamic 
replacement. 
Kellner * computes from the results of respiration experiments 
in which extracted rye straw was added to a basal ration that the 
furfuroids (presumably pentosans)* of this material must have con- 
tributed to the production of fat to as great an extent as starch or 
cellulose. (Compare p. 183.) A fortiort, therefore, they must be 
capable of protecting the body fat from oxidation. 
Organic Acids.—Mention was made in Chapter II of the fact 
that the organic acids, which are found to some extent in the food 
and which are produced in large amounts by the fermentation of 
the carbohydrates in the digestive apparatus of herbivora, are oxi- 
dized in the body. From this latter fact we should anticipate that 
they might serve as sources of energy to the organism, and this 
anticipation apparently has been confirmed by several investi- 
gators. 
Zuntz & v. Mehring t determined the amount of oxygen con- 
sumed by fasting rabbits before, during, and after the injection 
* Landw. Vers. Stat., 58, 457. 
+ Arch. ges Physiol., 32, 173. 
