country as a manure
for hops. It has also been used with beneficial results for wheat,
grass, and turnips. As a manure it is best suited for sandy or loamy
soils. Considerable quantities are exported to the sugar-growing
colonies as a manure for sugar-cane. Manures are made from other animal
refuse. It may be mentioned that lean flesh (containing 75 per cent of
water) has about 3 to 4 per cent of nitrogen,.5 per cent of alkalies,
and .5 per cent of phosphoric acid; that is to say, a ton of lean flesh
would contain about 70 lb. of nitrogen and 10 lb. of phosphoric acid. In
air-dried flesh, according to Payen and Boussingault (containing 8-1/2
per cent of moisture), there is 13 per cent of nitrogen. Flesh,
therefore, is, when properly composted, a valuable nitrogenous manure.
Dried flesh is generally made into a manure called meat-meal guano, the
composition of which we have already referred to in the chapter on
Guano.[240]

Hoofs, horns, hair, bristles, and wool, wool-waste and the intestines of
animals, have been used as manures. Hoofs and horns form a regular
source of artificial nitrogenous manure; the latter being obtained as a
bye-product in the manufacture of combs and other articles. They are in
the form of a fine powder; and in order to increase their rate of
action, which is very slow, they are often composted in America with
horse-manure before use. They have also been composted with slaked lime.
There can be no doubt that such treatment increases very considerably
their value. Their percentage of nitrogen seems to vary very much
according to the kind of animal from which they are derived. In nine
samples of horn the nitrogen was found to vary from 7-1/2 to 14-1/4 per
cent; giving an average of 11-1/3 per cent. The nitrogen seems rarely to
exceed 15 per cent. The amount of phosphoric acid they contain has been
found by various investigators to range from 6 to 10 per cent. S. W.
Johnson found only from .08 to .15 per cent in buffalo-horn shavings. In
France what is known as "torrefied" horn has been used. This is horn
which has been subjected to the action of steam. The nitrogen in this
material is considered to be more active than in ordinary horn.
According to Way, horns have been used for the hop crop with good
results. Ground hoof is very similar in composition to horn, and
contains about 14 to 15 per cent of nitrogen. Considerable quantities
are now used. It must be remembered, however, that horns, hoofs, h