and at the time when they most need them. On soils of this
nature, proper means should be used for the disintegration
of the soil. These are the use of Lime and the turning
in of green crops, the suffering of them to lie on the sur-
face or heavy dressings of coarse straw and litter. These
will decompose the inert minerals, of the soil, liberate its
Phosphate of Lime, and be equivalent in effects to an appli-
cation of this substance, as it brings it forward in an avail-
able form. Practice, in adopting general rules from the
above, would greatly err in adding annually on such soils
costly Phosphate of Lime, instead of the cheaper and more
permanent manures for its disintegration. There are other
soils on which Phosphate of Lime would act well, because it
does not exist in them in any form. On these it must be annu-
ally applied, no cultivation and no other manure can be a sub-
stitute for it. In the one case, practice teaches that Phosphate
of Lime is for the present a good application, but science
teaches practice, on the other, how to dispense with it by sub-
stituting cheaper manure, and how for the Phosphate of Lime
in the latter case, there can be no substitute.

There are thousands of acres of both of these descrip-
tions of land in Maryland.

Calcareous Manures.

Under this term we include such substances as are used in agri-
culture, for the effects of the lime and magnesia which they con-
lain.                                                                                   

The sources of lime are very various. There are common lime-
stone, magnesian limestone, shell marl, pure mail, the skeletons
of various shell-fish, the chief of which are oysters, shell sand
&c, &c. Substances containing lime as a characteristic ingre-
dient, are called calcareous from the Latin word, Calx, which sig-
nifies lime.

We will now give the nature, composition, history, uses and
abuses of lime, in agriculture. These last would make a paper as
long as the former; for it has been so often employed empirically
without success—so frequently used without benefit, that its virtues
have been obscured by the vices which surround it, It is like
other strong agents, powerful for good or evil, as it is wisely or im-
providently used, and beneficial or destructive, according to the
correctness of the principles which dictated its special applica-
tion.

Lime naturally exists most generally in combination with car-
bonic acid, where it forms the various kinds of limestone, marble

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