saline constituents were formed in water, and 
diffused through the disintegrated masses, and 
deprived of their impregnations by the frag- 
ments and granules; and larger or smaller 
quantities of vegetable and animal remains, 
either produced on the spot, or brought down 
from higher grounds by rains and streams, set- 
tled down upon the surface, and became inter- 
mixed with the moistened minerals. Rocks of 
widely different constitution sometimes occur 
in close juxtaposition to one another within the 
upper regions of the same river-basin,—and then 
they give rise to a very diversified soil upon the 
hills, and to a very mixed alluvium upon the 
plains ; but they sometimes occur also far asun- 
der from one another, each kind or class forming 
the floor and walls of an entire basin,—and then 
they give rise to somewhat uniform soils upon 
both hill and plain,—the silicious rocks to sand 
and gravel, the aluminous ones to clay, and the 
calcareous ones to chalk or to limestone gravel. 
Both the mixed soils from any given group or 
segregation of rocks, and the uniform soils from 
any one species or class of rock, are originally 
the same in all parts of the world; for so long 
| as rocks of any one kind or class or grouping 
| occur as sources of either detritus or alluvium, 
no matter where, their constituents are always 
the same, and must necessarily yield by disin- 
tegration the same sort of fragments and powder. 
Yet soils originally the same, or still minerally 
the same, differ widely and in many gradations 
from one another in consequence of mechanical 
condition, subsoil, situation, climate, and culti- 
vation. The coarseness of granules or fragments, 
even in cases where the material is intrinsically 
suited to evolve the highest fertility, may be so 
excessive in itself, and so unrelieved by the pre- 
sence of any finely divided matter as to render 
the soil absolutely barren. A soil of any kind 
immediately incumbent on rock or sand, espe- 
cially in such wet districts as those of the west 
coast of Britain and the greater part of Ireland, 
may be comparatively dry, open, and fertile, 
while exactly the same soil incumbent on clay 
or marl or on an impervious compound of clay 
and sand may be marshy, close, and almost 
worthless. 
more absorbent of moisture, has a freer internal 
circulation, and makes richer accumulations of 
salts, alumina, and organic remains, than the 
same soil in a cold wet country. A soil upona 
declivity makes better natural improvements, 
and is less exposed to natural deteriorating in- 
fluences, than a soil upon a level; and one upon 
a declivity looking to the sun is superior in 
these respects, to one upon a declivity with any 
other exposure. Soils in wet, cold climates, with 
comparatively slow vegetable growth and com- 
paratively little evaporation are liable to become 
choked with aquatic cryptogams, and even con- 
verted into sheer moors or bogs, while soils of the 
same kind in dry hot climates, with luxuriant 
_ SOIL. 
Any soil in a warm, dry country, is’ 
vegetable growth and great and rapid evapora- 
tion, remain sound and open, and generally pos- 
sess a constant, increasing, natural capacity of 
improvement. The ultimate composition of soils, 
therefore, is, in a very considerable degree, de- 
termined by the action or influence of subsoil, 
situation, and climate ; and so very greatly is it 
affected by cultivation—in the processes of pul- 
verization, of trenching, of fallowing, of cropping, 
and especially of manuring—that, in the case of 
many lands which have been specially reclaimed | 
or have been long in tillage, the original charac- 
ter of it cannot be traced. 
Classification of Soils—A good classification of 
soils, together with a simple, fixed, comprehen- 
sive, and well-defined nomenclature, is essential 
for enabling farmers to form comparative esti- 
mates of the different soils of their own farm or 
district, to trace the resemblances between 
these and the soils of other districts, to decide 
how far any peculiar treatment of one soil may 
be profitably imitated upon another, to deter- 
mine the kind and amount of mineral admixture 
which any soil may require for its proper textural 
amelioration, and especially to reap fair or full 
benefit, or even to obtain clear ideas or intelli- 
gible hints, from the multitudes of reports of 
valuable experiments on manures, methods of 
reclamation, improvements in culture, and other 
similar subjects, which abound in the agricul- 
tural periodicals of the day. The best which has 
yet been published is Schibler’s of Germany, 
slightly altered by Dr. Daubeny, and founded 
entirely on the relative proportions of the four 
chief constituents of all soils,—clay, sand, lime, 
and humus. “In this,” says Dr. Daubeny, “ we 
begin with those soils which contain little or no 
calcareous matter—at the outside, not so much 
as 5 per cent. of the whole mass. These, sup- 
posing them to possess 50 per cent. of clay, are 
placed under the head of argillaceous soils, and 
are distinguished into two orders, the first 
wholly destitute of lime, the second containing 
less than 5 per cent. of that earth. Each of 
these orders is then subdivided into three spe- 
cies, distinguished as rich, poor, and interme- | 
diate, according to the proportion of humus or 
vegetable mould present in them. If the amount 
of this ingredient be not more than 3 per cent. 
the soils are called poor, as the fertility of a soil 
is in all cases greatly influenced by the propor- 
tion of this ingredient; if it varies from 0°5 to 
15 per cent., it is called intermediate; if from 
15 to 5:0 per cent., it is distinguished as rich. 
The second class of soils comprehends those 
which contain from 30 to 50 per cent. of clay, 
and is denominated loamy. These likewise are 
divided into two orders, the one with, the other 
without lime ; and again into three species, ac- 
cording to the proportion of vegetable mould 
present in them. The third class embraces those 
soils which contain not more than 30 nor less 
than 20 per cent. of clay. They are called sandy 
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