Experiments on the Feeding of Stock. 
451 
Sheep 60. 
Sheep 67. 
grammes. 
grammes. 
, 206-762 ■ 
166-964 
337-246 
124-261 
9-900 
18-451 
Undigested contents of the stomach . , 
62-120 
16-851 
616-028 
326-526 
or in all 942-554 grammes of nitrogen (1-97 lbs.). 
The amount of nitrogen contained in the wool deserves special 
attention, not only on account of its absolute quantity, but of its 
varying proportions. In the one sheep we see that half as much 
again of nitrogen was assimilated in the wool as in the flesh, 
while in the other and inferior animal there was less in the wool 
than in the meat. 
Thus, of 3072 grammes, the excess of nitrogen in the food 
over that recovered in the manure, only 942-55 grammes appear 
to have been assimilated, and the remainder must necessarily 
have passed away by respiration and transpiration. 
M. Reiset remarks : " This amount of nitrogen exhaled appears 
at first sight to be large, and one might feel disposed to question 
the result, but we must remember that the experiment had lasted 
168 days, and that in the first period the two sheep had expe- 
rienced a remarkable loss of substance, amounting to more than 
13 lbs. To recover this loss, the organism had to fix a certain 
amount of nitrogen, of which no account could be taken : and it 
will be near the mark to assume that of these 13 lbs., 6 J were 
muscular tissue, containins: about 105 grammes of nitrosren. 
This will leave us 20-25 grammes exhaled by two sheep in 168 
<lays, or 6 grammes per head per day for sheep fed on rich nitro- 
genous food. 
" I may remind the reader that in a paper on Respiration, 
published in 1849 (in the ' Annales de Chimie,' &c., 3rd Series, 
vol. xxvi.) by M. Regnault and myself, we show that different 
animals on store keep constantly exhale nitrogen. The amount 
of the gas then found to be exhaled was as considerable as that 
now arrived at by the indirect process." 
The following table (see p. 452) gives the amount of food in 
lbs., and the nitrogen in that food stated in French grammes, for 
the lour periods. The amount of the excrements is also given 
below in lbs., and its nitrogen in grammes ; the difference stated. 
The sum of the differences throughout, calculated for two sheep, 
amounts to 3072 grammes. The amount of the nitrogen reco- 
vered in the food was, for the four periods, 72, 57-7, 56-67, and 
49 per cent, respectively. 
