of the Guano with sufficient accuracy to protect the planter
and farmer.

There is another article under the name of "El Roque
Guano," which is not entitled to the name of Guano, it being
a mineral product and not the excrement of birds or other
animals, it is not a phosphate of lime such as is found in
Bones, Mexican and Columbian Guano, but a phosphate of
iron and alumina, somewhat similar in composition to the
deposits of blue earth found in the neighborhood of Still
Pond, in Kent County, in Worcester County, on the farms
of Dr. Watkins, J. T. Hodges, Esq., Hon. J. S. Sellman in A.
A. Co., and on the farms of J. Mulliken, Mr. Berry and others
in Prince George's County; and is worth no more than the
said blue earth, (vivianite,) when existing in a state of pu-
rity; farmers will not be induced by its name to purchase it,
for it is a fase one. Unless the above advice is followed they
are constantly liable to the grossest imposition in the pur-
chase of Mexican, Columbian and other phosphatic guanos,
more so in these than in Peruvian, the former are brought
here by various individuals, few of whom know the difference
between a good and a bad article, and the knowledge on the
part of the purchaser is not increased by the inspection laws,
as I shall show when making some recommendations as to
their revision.

The proper quantity of phosphate of lime per acre is that
contained in about five bushels of bone dust, two hundred
and fifty pounds of phosphatic guano, which should contain
about fifty per cent, of phosphate of lime or about two hun-
dred pounds of a veritable superphosphate of lime. These are
not exactly equivalent numbers, but sufficiently near so for
practical purposes.

Mode of Application—Soils and Crops to which it should be
applied.—The best mode of application in order to receive the
full benefit of phosphate of lime in the form of bone dust, or
the phosphatic guanos, is to apply it broad-cast at the time
of sowing wheat, or to the land when it is prepared for the
planting of corn, tobacco, cabbage, &c. Manures of this
class are not so immediately forcing as Peruvian Guano, but
they act on the plant at a later period of its growth, whilst
the leaves, stalk and grains are in the process of formation.
At this time the roots of the plants have entered far and
wide into the ground, and the phosphate of lime should be
equally diffused through the land in order to be taken up by
them and introduced in the body of the plant. This diffusion
cannot take place but to a very limited extent when phos-
phatic manures are put in the bill or used with a drill.

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