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measure as to the capacity and value of the soil in general, as al-
ready mentioned. That is, the exterior disposition of a soil is far
more highly esteemed by him than the degree of its absolute capa-
bility of giving nourishment to plants, inasmuch as by purchasing
a farm, it is less valuable for him to know how much of nourish-
ing substances is at present in the soil, than to know whether a
soil shows such a condition as to render it capable of producing
fair crops by a proper treatment. He looks, therefore, most
especially to its physical properties, and proves by manual exam-
inations, as to the compressibility in the wet and dry state, as to
the color, the depth of the soil, the quality of the sub-soil, the lo-
cation, general climatic relations, &c, whether the earth is loose,
easily falls to pieces by exposure to the air. possesses the proper
degree of consistence, without giving too much resistance to agri-
cultural implements; retains the absorbed moisture in the neces-
sary degree, without becoming wet and cold, &c.

Although these examinations are indeed of quite a practical
character, the Chemist still is enabled to aid the farmer in them.
For the Chemist knows exactly the nature of the components of
soils, and therefore the part which each single substance takes on
the general character of them; he knows also the nature of the rocks,
by the disintegration of which the soil was formed, and therefore
the particular condition, the manner of combination, in which
those components are present in soils. The investigations of the
Chemist into this matter, assist if not in the judgment of the qual-
ity of soils, yet, in the judgment of means and ways, which ought
to be taken for the improvement of a particular soil, I say they
lead to results which can be expected with more confidence than
those which are founded upon the experiment of the farmer alone.
We shall see in the following that, in relation to an improvement
of the soil in general, as to its texture, the Chemist may give an
important judgment about it as well as the farmer; and in many
cases a judgment which the farmer would never have reached by
himself.

A general geological glance into the localities of those soils,
which are in particular under our consideration, will lead us at
once to some important conclusions. The soil of the north-
east part of Maryland, (Carroll County, Harford County, Balti-
more County, and a part of Frederick and Cecil,) is composed
chiefly of the fragments of volcanic rocks, upon which the soil
directly lies, intermixed with various quantities of alluvial matter.
These volcanic rocks, as Granite, Syenite, Mica-Slate, and others,
are silicates according to their chemical nature. We meet them in
these localities almost every where, covered only by alluvial forma-
tions of small thickness. All those formations of aquatic origin,
which were formed by precipitation from their solution or suspen-
sion in water, and which, in their regular occurrence, we find