138 PRINCIPLES OF ANIMAL NUTRITION. 
ficult to decide. Munk also cites results obtained by Salkowski,* 
who observed the nitrogen excretion of a dog on a light ration con- 
taining but little proteids to be scarcely greater than in the absence 
of all food. 
E. Voit & Korkunoff (loc. cit.) also included the carbohydrates 
in their investigation upon this subject, following the same general 
method as in the experiments with fat. The following are their 
results compared with the fasting proteid metabolism exactly as 
in the former case: 
Per Cent. of Minimum of Food Nitrogen. 
Total Energy D d 
Live |Nitrogen| Supplied by |. Per Cent.of Fasting 
Weight, Excre- : Metabolism. 
K 
tion 
88. | Fasting, | Carbo- Fou. aeoust 
Grms. |hydrates,| pe, + Total, | Proteid, 
Per Cent.! Cent. Per Cent.|Per Cent. 
Series I: } 
Experiment 3a| 24.0 | 4.93 78 | 91 | >5.43 | >110 | >133 
« 2 24.6 | 4.94 79 92 5.00 101 124 
Series II: . 
Experiment 5 2 4.98 111 | 122 5.11 103 126 
se 1 24.1 5.25 115 | 126 | >4.91 >94 | >123 
nf 2 24.7 | 4.94 118 | 131 | <4.35 <88 | <108 
re 4 30.0; 4.08 122 | 136 | <4.47 | <110 | <134 
ee 3b| 24.0 | 4.93 155 | 168 | <4.48 <91 ) <111 
The authors also compute from a few experiments by C. Voit 
and by Rubner values not inconsistent with the above. 
When compared with the total nitrogen excretion, the results of 
Voit & Korkunoff show in but a single case a minimum unmistak- 
ably greater than the fasting proteid metabolism. In three cases 
the minimum falls below this amount, while in the remaining cases 
it is either substantially equal to it or doubtful. Regarded in this 
way, they seem on the whole in accord with Munk’s claim that the 
proteid metabolism may be reduced below the fasting limit. Voit 
& Korkunoff, however, dispute this and subject Munk’s experi- 
ments to a detailed criticism, the prineipal points of which are that 
in the earlier experiments, as noted above, the nitrogen excre- 
tion was irregular and that the result of a single day is arbi- 
trarily selected for comparison, while in the later experiments no 
* Zeit. physiol. Chem., 1, 44. 
