m, say one-fourth the full bulk, has been added.
In this way much of the ammonia that otherwise would be evaporated from
the manure is arrested and retained.

Some growers, when they first shake out their fresh manure, add the full
complement of loam to it at once and mix them together. Others, again,
Mr. Denton, of Woodhaven, for instance, prepare the manure in the
ordinary way and when ready for use add the quota of loam. I use good
sod loam for two reasons, namely, because it is the very best that can
be used for the purpose, and, also, after being used in the mushroom
beds it is a capital material, and in fine condition for use in potting
soft-wooded plants. But the loam commonly used to mix with the manure is
ordinary field soil. If the loam is ordinarily moist to begin with, and
also the manure, there is very little likelihood of any of the material
getting too dry during the preparation. And much less preparation is
needed, for the presence of the loam lessens, considerably, the
probability of hasty, violent fermentation.

Mr. Withington, of South Amboy, N. J., uses rather a stinted amount of
loam in his manure. He writes me: "We made up our beds this year with a
proportion of loam in the manure, say one part loam to eight parts
manure, but have always used clear manure heretofore, and I think the
beds hold out longer than when only manure is used."

CHAPTER IX.

MAKING UP THE MUSHROOM BEDS.

The place in the cellar, shed, house, or elsewhere, where we intend to
grow the mushrooms, should be in readiness as soon as the manure has
been well prepared and is in proper condition for use. The bed or beds
should be made up at once. The thickness of the beds depends a good deal
upon circumstances, such as the quality of the manure,--whether it is
plain horse manure, or manure and loam mixed together,--or whether the
beds are to be made in heated or unheated buildings, and on the floor or
on shelves. Floor beds are generally nine to fifteen inches deep; about
nine inches in the case of manure alone, in warm quarters, and ten to
fourteen inches when manure and loam are used. In cool houses the beds
are made a few inches deeper than this so as to keep up a steady, mild
warmth for a long time. The beds may be made flat, or ridged, or like a
rounded bank against the wall; but the flat form is the commonest, and
the most convenient where shelves are also used in the same building.
Shelf beds are generally nine in