aluable constituents, even when manure is fermented in the open air and
exposed to ordinary rain and snows during an English winter. But it also
shows that when the manure has been fermented for six months, and is
then turned and left exposed to the rain of spring and summer, the loss
is very considerable.

The five tons (10,000 lbs.,) of fresh manure placed in a heap on the 3d
of November, are reduced to 7,138 lbs. by the 30th of April. Of this
4,707 lbs. is water. By the 23d of August, the heap is reduced to 7,025
lbs., of which 5,304 lbs. is water. There is nearly 600 lbs. more water
in the heap in August than in April.

Of total nitrogen in the heap, there is 64.3 lbs. in the fresh manure,
63.9 lbs. in April, and only 46.3 lbs. in August. This is a great loss,
and there is no compensating gain.

We have seen that, when five tons of manure is fermented for six months,
in winter, the nitrogen in the soluble organic matter is increased from
14.9 lbs. to 21.4 lbs. This is a decided advantage. But when the manure
is kept for another six months, this soluble nitrogen is decreased from
21.4 lbs. to 13.2 lbs. We lose over 8 lbs. of the most active and
available nitrogen.

And the same remarks will apply to the valuable soluble mineral matter.
In the five tons of fresh manure there is 154 lbs. of soluble mineral
matter. By fermenting the heap six months, we get 204 lbs., but by
keeping the manure six months longer, the soluble mineral matter is
reduced to 138 lbs. We lose 66 lbs. of valuable soluble mineral matter.

By fermenting manure for six months in winter, we greatly improve its
condition; by keeping it six months longer, we lose largely of the very
best and most active parts of the manure.

CHAPTER XV.

KEEPING MANURE UNDER COVER.

Dr. Voelcker, at the same time he made the experiments alluded to in the
preceding chapter, placed another heap of manure _under cover_, in a
shed. It was the same kind of manure, and was treated precisely as the
other--the only difference being that one heap was exposed to the rain,
and the other not. The following table gives the results of the
weighings of the heap at different times, and also the percentage of
loss:

Manure Fermented Under Cover in Shed.

Table Showing the Actual Weighings, and Percentage of Loss in Weight,
of Experimental Heap (No. II.) Fresh Farm-Yard Manure Under Shed,
at Different Periods of the Year.