, the quality of the manure is
excellent, and its valuable matters are most thoroughly economized.

Although covered dung-pits have been but little used, their benefits
have been indirectly obtained by the method of box-feeding, one of the
great advantages of which is held to be the production of a manure of
superior quality to that obtained in the old way. In box-feeding none of
the dung or urine is removed from under the animals, but is trampled
down by their feet, and new quantities of litter being constantly added,
the whole is consolidated into a compact mass, by which the urine is
entirely retained. Whatever objection may be taken to this system, so
far as the health of the animals is concerned, there is no doubt as to
the complete economy of the manure, provided the quantity of litter used
be sufficient to retain the whole of the liquid. But its advantage is
entirely dependent on the possibility of fulfilling this condition.

Whether box manure is really superior to that which can be prepared by
the ordinary method is very questionable, but it undoubtedly surpasses a
large proportion of that actually produced. It is more than probable,
however, that the careful management of the manure-heap would yield an
equally good product. It is manifest that the same number of cattle, fed
in the same way, on the same food, and supplied with the same quantity
of litter, must always excrete the same quantities of valuable matters;
and the only question to be solved is, whether they are more effectually
preserved in the one way than the other? It will be readily seen that
this cannot be done by analysis alone, but that it is necessary to
conjoin with it a determination of the total weight of manure produced;
for though, weight for weight, box manure may be better than ordinary
farm-yard manure, the total quantity obtained by the latter method, from
a given number of cattle, may be so much greater, that the deficiency in
quality may be compensated for. At the present time our knowledge is too
limited to admit of a definite opinion on this subject, but it is highly
deserving of the combined investigation of the farmer and the chemist.

Supposing the conditions which produce the manure containing the largest
quantity of nitrogen to have been fulfilled, we have now to consider
those which affect its evolution in the form of ammonia. This change is
effected by _fermentation_. When a quantity of manure is left to itself
it becomes h