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1852, and hope now that expeditions of this sort will be under-
taken, instead of the long, expensive and useless one to the Pacific
ocean.

Specimens of the guano found on this island were sent to the
Patent Office for distribution. It was analyzed at my office, and
only there, and found to contain but a very small amount of am-
monia. It was a phosphatic guano like the Mexican.

These are the principal manures which afford nitrogen to plants,
they are expensive, liable to loss by improper or careless manage-
ment, and are most efficient in the production of crops, this should
teach us the most cautious behaviour in relation to their purchase,
and, when purchased, their most careful subsequent treatment and
application. On these several points i have given all requisite in-
formation to the Planter and Farmer.

The rules which I have laid down for each and the directions
given, are educed from the observations and experience of a large
number of our most reliable practical agriculturalists, from scientific
deductions, from the nature and composition of the articles spoken
of, and it is advice necessary for the protection of all tillers of the
soil, which they should follow.

Phosphatic Manures.

The manures which supply Phosphoric acid to plants, are Bone
Dust, Superphosphate of Lime, and various guanos under various
names, brought to our markets from islands in the Gulf of Mexico
and the Caribbean Sea.

We shall in the first place speak of Bone Dust and the manures
made from it.

Bone Dust—Phosphate of Lime—Superphosphate—Biphosphate
or Dissolved Bones.—The necessity of the chief elements of bones,
phosphoric acid and lime, to the production of crops needs no
proof, whether we examine the constituents of fertile soils, the
crops cultivated for the support of men and animals, or the compo-
sition of men and animals themselves, which is derived from food
furnished by crops. In the present article I shall confine myself
to the preparation and best mode of application of the phosphates,
uniting as much brevity as possible, with explanations full enough
for the good understanding of the subject.

The bones of all animals are composed mainly of phosphoric acid
and lime, forming what is called bone phosphate of lime; besides
these they contain a small proportion of phosphoric acid, in union
with magnesia, (phosphate of magnesia,) carbonate of lime, soda and
potash; the two last, and several other substances in very small
proportions, of no practical value here—these are the mine a
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