On the food of man in relation to his useful work / by Lyon Playfair.

  • Lyon Playfair, 1st Baron Playfair
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: On the food of man in relation to his useful work / by Lyon Playfair. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    the urine. We can only test this when animals are fed on a flesh diet free from fat. Luckily there are two classes of experiments of this kind, one of them being by Bischof and Voit,^ and the other by PettenkofFer and Voit.^ The results of the former, omitting the starving experiments on the dog, are as follows :— Grammes of Flesh. C in Urea. C in CO4. First Series, . . Second „ . . Third „ . . Fourth „ . . Fifth „ . . Sixth „ . , 1800 1500 1200 1800 1800 2000 Grammes. 24-2 21-6 17-7 24- 9 25- 6 30-3 Grammes. 180-8 162-1 132-6 186-5 223-3 228-5 Mean, . . . 1383 240 185-6 Before using these figures, we must correct them, for the one per cent, of fat which, according to these authors still remained in the flesh. If we suppose the fat to contain 77 per cent, of carbon, then 13-83 grammes of fat, in the average daily supply of 1383 grammes of flesh, would contain 10-6 grammes of carbon. Hence we have in reality 175 grammes of the carbon in the carbonic acid due to the flesh alone. From this we obtain the ratio— 24: 175:: 1 x = 7'29. In Pettenkoff-er and Voit's experiments, conducted in a like way, but where no correction requires to be made for fat, 21-6 grammes of carbon were found in the urea, I Die Gesetze der Ernill.rung der Fleischfressers, S. 61, e< s.r, Ann. der Ch, und Phar. Suj)],. Bd., 18G.3.