2 5 0
17. Meadow-hay 1 10 0
18. Oat-straw 0 13 6
19. Wheat-straw 0 12 6
20. Barley-straw 0 10 6
21. Potatoes 0 7 0
22. Mangolds 0 5 0
23. Swedish turnips 0 4 3
24. Common turnips 0 4 0
25. Carrots 0 4 0

All the saline matter contained in the food is either converted into
flesh, or is recoverable in the form of manure, but a portion of its
nitrogen appears to be lost by respiration and perspiration. Reiset
states that 100 parts of the nitrogen of food given to sheep upon
which he experimented, were disposed of as follows:--

Recovered in the excreta 58.3
Recovered in the meat, tallow, and skin 13.7
Lost in respiration 28.0
------
100.00

Haughton's experiments, performed upon men, gave results which proved
that no portion of the nitrogen of their food was lost by perspiration
or by respiration. Barral, on the contrary, asserts that nitrogen
is given off from the bodies of both man and the inferior animals.
Boussingault states that horses, sheep, and pigs exhale nitrogen.
A cow, giving milk, on which he had experimented, lost 15 per cent.
of the nitrogen of its food by perspiration. The amount of nitrogen
which Reiset states that sheep exhale is exceedingly great, and it
is difficult to reconcile his results with those obtained by Voit,
Bischoff, Regnault, Pettenkofer, and Haughton. Of course, men and sheep
are widely different animals; but still it is unlikely that all the
nitrogen of the food of man should be recoverable in his egesta, whilst
nearly a third of the nitrogen of the food of the sheep should be
dissipated as gas. I think further experiments are necessary before this
point can be regarded as settled; and it is probable that it will yet be
found that all, or nearly all, of the nitrogen of the food of animals is
recoverable in their egesta.

Regarding, then, an animal as a mechanism by which meat is to be
"manufactu