SOIL. 
tact with carbonate of lime (chalk), a gradual 
change takes place, and the resulting compounds 
are muriate of lime and carbonate of soda; 
which latter is a powerful alkali, and is of great 
value, on account of its capability of acting upon 
oxidized organic matter. 7. Thus the organic 
matter has again become combined with saline 
matter, but this time it forms a very soluble 
salt, which consequently is absorbed by plants, 
and is more useful than it would have been pre- 
viously, because it is more highly oxidized. 8. 
As, however, the plants do not require so large 
a quantity of alkaline matter as they would in 
this way receive, the superabundant portion is 
returned to the soil, with other excrementitious 
matters, and thus, by coming into contact with 
the muriate of lime, produced in the manner 
formerly related, a contrary change takes place, 
and carbonate of lime and muriate of soda are 
reproduced. For, strange as it may appear to 
those not conversant with chemistry, although 
carbonate of lime and muriate of soda, when in 
contact in a moist state, are gradually converted 
into muriate of lime and carbonate of soda, still, 
if these latter salts meet together in solution, 
they immediately resume their former state of 
chalk and common salt. These are a few of the 
very complicated changes which are constantly 
occurring in soil; but a careful consideration of 
them will enable us to draw the following im- 
portant practical deduction, viz., that multitu- 
dinous as they appear, still soil is so admirably 
adapted for the duties which it has to perform, 
that the farmer has merely from time to time to 
add fermenting matters to his soil, and he may 
rest assured of his plants never lacking their 
proper nourishment.” 
The Peculiar Vegetations of Soils.—Many plants 
prosper equally on many kinds of soils and in 
widely different situations; most are diffused 
over a great diversity of surface by means of 
some one or more of the mighty agencies which 
are everywhere at work for covering all the earth 
with vegetable wealth and beauty; and few are 
so entirely dependent on the composition and 
depth and texture of soils, irrespective of capa- 
city for the free play of heat and moisture and 
atmospheric influences, as to afford invariable 
indication of the mineral and economical and 
chemical characters of the ground on which they 
grow. Yet some great groups and families of 
them always affect peculiar conditions of land or 
water or elevation, and therefore make striking 
intimation of the presence of these conditions 
wherever they exist. “Thus,” to adopt the 
words of Professor Macgillivray, “if, while tra- 
versing an extended heath, we observe at a dis- 
tance a spot covered with fresh verdure, we infer 
that the soil there is certainly not peat; and if, 
on approaching it, we see pos, vicie, and other 
plants usually found in rich pasture, we infer 
that the soil is vegetable ; and so of other soils. 
If, on the other hand, in a rich country, we see 
(Lea 
ee a aa 
tracts, whether of hill or plain, covered witha | 
brown vegetation, which we know to be heath, 
we infer that the soil is peat. Still, even among 
these general appearances, there are few that | 
Thus, on seeing a | 
long line of trees, which we know by their phy- | 
have direct reference to soil. 
siognomy to be alders or willows, we infer that a 
river flows beside them, but we can make no in- 
ference with respect to the soil. And thus, were 
it possible that we should be led blindfolded to a 
spot, in which we should open our eyes upon a 
rivulet, margined with bright green moss, among 
which Saxifraga stellaris, Alchemilla alpina, Si- 
lene acaulis, appeared here and there, we might 
assuredly pronounce ourselves in an alpine re- | 
gion; but what the peculiar soil of the spot 
might be, we would require to remove the turf 
to discover, and thus trust to the colour, texture, 
adhesion, and other qualities of the soil itself for 
a disclosure of its nature, rather than to any- 
thing growing upon its surface. Thus we see 
that Nature, simple in her grand plans, yet com- 
plex even to infinity in her details of execution, 
presents nothing of which we can acquire a 
tolerable knowledge, by viewing it on one side 
only, or which the mind can grasp by employ- 
ing a single principal or pervading idea for that 
purpose. The grand principle of vegetation is 
simple in its design; but view it in detail, and 
its complication astonishes and bewilders. To 
become the abode of animals, it was necessary 
that the earth should be covered with vegetables ; 
but from the cedar of Lebanon to the small plant 
(whatever that may be) that grows on the wall, 
from the magnificent jagua of tropical America 
to the diminutive radiola of northern Europe, 
not to take other examples still more striking, 
how multiplied the proportions, the forms, the 
colours, the qualities of all kinds, and how differ- 
ent the circumstances! It is the same sun that 
calls forth, and, when thus elicited, gives vigour 
to the vegetation, the same earth that supports 
it, the same moisture that swells its vessels, the 
same air that furnishes the medium in which it 
lives; but-amid all this singleness of general, 
how multiple the variations of partial or consti- 
tuent causes, and how infinitely diversified their 
results !” 
The comparatively few British plants, how- 
ever, which have a certain and uniform charac- 
ter of habitat, perform a valuable service to in- 
telligent observers, in some cases by indicating 
the presence or predominance of certain constitu- 
ents in the soil, in others by indicating the aggre- 
gate composition of the soil, in others by indicat- 
ing the comparative states of different specimens 
of soil of the same generic composition, in others 
by indicating the pressure or excessive power of 
some deteriorating influence which is capable of 
correction, and in many by suggesting or reveal- 
ing errors which have been committed in the 
management of land or methods which may be 
adopted for reclamation or enrichment. We 
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