On the Valuation of Unexhausted Manures. 
603 
question, that the amount of the manure-constituents of the food 
carried off by fattening increase is under all circumstances so 
small that, for the purposes of our calculations of manure-value, 
even a considerable variation from the average amounts assumed 
to be taken up by the animal would affect the final result but 
little. 
The next division of the Table (II., pp. 600-1), comprising 
seven columns, relates to the amount, and to the distribution, of 
the nitrogen of the foods. There are given — the amounts of it per 
cent., and per ton, as in Table I. ; the actual amount estimated 
to be contained in the increase in live-weight of the animal 
consuming the food, and the percentage of the total nitrogen 
consumed which is so retained in the increase ; the amount of 
the nitrogen of the food remaining for manure, the amount 
of ammonia to which it corresponds, and its money-value 
reckoned at 6f7. per lb. of ammonia. 
Throughout the calculations, we have assumed only fattening 
increase to be produced, and that this will contain 8 per cent, 
of nitrogenous substance, corresponding to 1-27 per cent, of 
nitrogen in the increase. It will be seen that, according to the 
figures, the only food in the list of which a ton is estimated to 
contribute more than 5 lbs. of nitrogen to the fattening increase 
is linseed, and that in the case of ncne of the cakes, or of the 
leguminous seeds, will 1 ton contribute 5 lbs. of nitrogen to the 
increase ; whilst the amount is in several cases under 4 lbs. 
A ton of the cereal grains, or of their products (and locust 
beans), generally contributes under 4 lbs. ; a ton of hay or straw 
less than half as much ; and a ton of roots very much less still. 
To put it in another way : of the total nitrogen consumed in 
the foods rich in that substance, such as the cakes and the 
leguminous seeds, there is generally less than 5 per cent, 
retained in the fattening increase in live-weight. The cereal 
grains, on the other hand, which are much less rich in nitrogen, 
contribute a much larger proportion of their total amount to 
the increase ; indeed, generally about 10 per cent, of it. The gra- 
mineous straws contribute a higher proportion still ; whilst the 
roots lose by feeding on an average only about 5 or 6 per cent. 
It is thus seen that, when fattening increase only is produced, 
the proportion of the nitrogen of the food which is retained by 
the animal, and so lost to the manure, is very small in the case 
of the richer foods, but more in that of the poorer ones ; but 
even with them it seldom exceeds 10 per cent., excepting with 
the straws. It may be assumed, however, that when the foods 
are consumed by store animals, about twice as much of the 
nitrogen of the food is retained by the animal, and so lost to the 
manure. And when, as is more and more the case with early 
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