116 PRINCIPLES OF ANIMAL 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 case of fat, 
cause an increase in the proteid metabolism. 
Food. Urea 
per Day, 
Meat, Carbohydrates, | rms. 
Grms. Grms. 
June 23-July 2, 1859 Aguistwing oeiaeide ees ee 500 300-100 35.4 
Withy? Deby AY cae combate lela ancy 500 0 39.9 
July 4-10, 1864.........0...00..0000. 800 0 59.1 
“ ag ee oe hecacenee cave taainsd iaca Kee Giactiaraed 800 100-400 54.5 
oe TQ SOO; EO 8 oe dh idan Rua ouabmutiahiuahe Re 800 0 63.8 
July 23-26, 1864.........0. 00.20 1000 0 73.5 
a 10 a am eee ee ar 1000 100-400 64.4 
SE 28= Aig 11864 a5: o wig aawigu inate ass 1000 0 79.6 
June 29-July 8, 1863 RONGe ake see ae 1500 0 114.9 
July BHO ee | eae caters Snead auineess 1500 200 103.3 
Jan. 6518592. aa aawaawenaw eso ee Parca ad 2000 0 143.7 
8° TELA, V859 2.5, thank cha epee ee Gece 2000 200-300 131.0 
This effect of the carbohydrates, like that of fat, has been abun- 
dantly confirmed by later investigators and is one of the well-estab- 
lished facts of physiology. Weiske t 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 Mdéckern, 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. 
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