116 PRINCIPLES OF ANJMAL NUTRITION. 
Starch and Sugars.—The investigations of C. Voit * show that 
starch or sugar added to a.proteid diet causes, as does fat, a decrease 
in the elimination of urea. Voit found an average decrease of 
about 9 per cent. in the proteid metabolism, the extremes being 5 
and 15 per cent. with varying amounts of carbohydrates. An in- 
crease in the carbohydrates, the proteid food remaining the same, 
tended to further diminish the excretion of urea. The following 
examples illustrate this effect of the carbohydrates. When given 
to a fasting animal, carbohydrates did not, as in the ease of fat, 
cause an increase in the proteid metabolism. 
Food. 
Urea 
per Day, 
Meat, | Carbohydrates, | Grms. 
e |' Grms. Grms. 
June 23-July 2, 1859 au Search Wienges ae ateranoxeles 500 300-100 35.4 
Ditlye a6 secatitas oars ee eames ee 500 0 39.9 
July 4-10, 1864..................000- 800 0 59.1 
BE NORIO gS maa ie cnacauthig ive tems bile eran ghar tie 800 |: 100-400 54.5 
Be PE ee omnes peatemenseeten, ve 800 o | 63.8 
July 23-26, 186400554 csv wsensscesweess 1000 0 73.5 
Oe 26-28). aeons Re ern or 1000 100-400 64.4 
“ "28-Aug. 1, 1864..........--..0 00 1000 0 79.6 
June 29-July 8, 1863 Aiiiaeydseneonaie Socernistse 1500 0 114.9 
PUNY. BRN urcautsecaresinocsias deaed.baquase 1500 200 103.3 
TAD. 6: 180s en emcee aun hale inchs inee Marine aeee 2000 0 143.7 
Oe ELL UBD cama ccna eae K atsuticaientras 2000 200-300 131.0 
This effect of the carbghydrates, like that of fat, has been abun- 
dantly confirmed by later investigators and is one of the well-estab- 
lished facts of physiology. Weiske ¢ in particular has investigated 
the effect of the non-nitrogenous nutrients upon the metabolism 
of sheep, while Miura { and Lusk § have shown that the abstraction 
of carbohydrates from the diet of a man results in a marked increase 
in the proteid metabolism. The following data, taken from Kell- 
ner’s extensive respiration experiments at’ Méckern, illustrate the 
same effect of starch in the case of cattle: 
* Zeit. f. Biol., 5, 434. 
+ Zeit. physiol. Chem. 21, 42; 22, 137 and 265. 
} v. Noorden, Pathologie des Stoffwechsels, p. 117. 
§ Zeit. f. Biol., 27, 459. 
