GARDENING.-NO. 7 
287 ' 
About fencing—why should I quarrel about 
this matter, although the editor of the Agricul¬ 
turist has something on this subject? We cannot 
teach “Wahoo Indians” that we can do without 
fences. 
“ Write again, Doctor.” Thank you, friend 
Reviewer; but this liberty is already secured to me 
by our A. B. A. But if he would not admit my ar¬ 
ticles, I would write for somebody else, or burst. 
The steam gathers so fast, that I must let off occa¬ 
sionally. But, friend Reviewer, be ye careful, you 
may drive some valuable pens off; many are wary, 
they can’t bear to be ridiculed. M. W. Philips. 
Edward’s Depot, Miss., June 14, 1846. 
GARDENING.—No. 7. 
The next step in the study of the science of gar¬ 
dening, is to consider the natural agents of vege¬ 
table culture. 
The earthy matters which compose the surface 
of the earth, the air and light of the atmosphere, 
the w T ater precipitated from it, the heat and cold 
produced by the alternation of day and night, and 
by chemical composition and resolution, include all 
the elements concerned in vegetation. 
Earths are the productions of the rocks which 
are exposed on the surface of the globe, and soils 
are earths mixed with more or less of the decom¬ 
posed organized matter afforded by dead plants and 
animals. Earths are, therefore, variously com¬ 
posed, according to the rocks or strata which have 
supplied their particles. Sometimes they are 
chiefly formed from slate rocks, as in blue clays; 
at other times from sand stone, as in siliceous soils; 
and mostly of a mixture of clayey, slaty, and lime¬ 
stone rocks, blended in proportions as various as 
their situations. Such we may suppose to have 
been the state of the surface of the dry part of the 
globe, immediately after the last disruption of the 
crust ; but in process of time the decay of vege¬ 
tables and animals forms additions to the outer sur¬ 
face of the globe, and constitutes what are called 
soils; the difference between which and earths is, 
that the former always contains a portion of vege¬ 
table or animal matter. 
The manner in which rocks are converted into 
soils, Sir H. Davy observes, may be easily con¬ 
ceived by referring to the instance of soft granite. 
This substance consists of three ingredients, quartz, 
feldspar, and mica. The quartz is almost pure 
siliceous earth in a crystalline form. The feld¬ 
spar and mica are very compounded substances; 
both contain silica, alumina, and oxide of iron; in 
the feldspar there is usually lime and potassa, and 
in the mica, lime and magnesia. When a granite 
rock of this kind has been long exposed to the in¬ 
fluence of the air and water, the lime and potassa 
contained in its constituent parts are acted upon by 
water or carbonic acid; and the oxide of iron, 
which is almost always in its least oxidized state, 
tends to combine with more oxygen ; the conse¬ 
quence is, that the feldspar decomposes, and like¬ 
wise the mica ; but the first the most rapidly. The 
feldspar, which is, as it were, the cement of the 
stone, forms a fine clay; the nv'ca partially decom¬ 
posed mixed with it as sand; and the undecom¬ 
posed quartz appears as gravel of different degrees 
of fineness. As soon as the smallest layer of earth 
is formed on the surface of the rock, the seeds of 
lichens, mosses, and other vegetables of the kind, 
which are constantly floating in the atmosphere, 
and which have made it their resting place, begin 
to vegetate ; their death, decomposition, and decay, 
afford a certain quantity of organizable matter, 
which mixes with the earthy materials of the 
rock; in this improved soil more perfect plants are 
capable of subsisting ; these in their turn absorb 
nourishment by the agency of water and the atmo¬ 
sphere ; and, after perishing, afford new materials 
to those already provided; the decomposition of the 
rock still continues; and at length, by such slow 
and gradual processes, a soil is formed, in which 
even forest trees can fix their roots, and which is 
fitted to reward the labors of the cultivator. 
The formation of peaty soil is produced from 
very opposite causes, and it is interesting to con¬ 
template how the same effect may be produced by 
different causes, and the earth which supplied 
almost all our wants, may become barren alike 
from the excessive application of art, or the utter 
neglect of it. Continual pulverization and crop¬ 
ping, without manuring, will certainly produce a 
hungry, barren soil; and the total neglect of fertile 
tracts will, from their accumulated vegetable pro¬ 
ducts, produce peaty soils and bogs. Where suc¬ 
cessive generations of vegetables have grown upon 
a soil, unless part of their produce has been carried 
off by man, or consumed by animals, the vegetable 
matter increases in such proportion, that the soil 
approaches to a peat in its nature, and if in a situa¬ 
tion where it can receive water from a higher dis¬ 
trict, it becomes spongy, and permeated with that 
fluid, and is gradually rendered incapable of sup¬ 
porting the nobler classes of vegetables. Lakes 
and pools of water are sometimes filled up by the 
accumulation of the remains of aquatic plants; and 
in this case a spurious peat is formed. The fer¬ 
mentation in these cases, however, seems to be of a 
different kind. Much more gaseous matter is 
evolved; and the neighborhood of morasses, in 
which aquatic vegetables decompose, is generally 
aguish and unhealthy; while that of the true peat, 
or peat formed on soils originally dry, is always 
salubrious. 
Soils may generally be distinguished from mere 
masses of earth, by their friable texture, dark color, 
and by the presence of some vegetable fibre or car¬ 
bonaceous matter. In uncultivated grounds, soils 
occupy only a few inches in depth on the surface, 
unless in crevices, where they have been washed in 
by rains; and in cultivated soils their depth is 
generally the same as that to which the implements 
used in cultivation have penetrated. 
Systematic order and an agreed nomenclature 
are as necessary in the study of soils, as of plants 
and animals. "The number of provincial terms for 
soils which have found their way into books on 
cultivation, is one reason why so little use can be 
made of their directions. A correct classification 
of soils may be founded on the presence or absence 
of organic or inorganic matter in their bases. This 
will form two grand classes: viz., primitive and 
secondary. These classes may be subdividedinto 
orders, founded on the presence or absence of 
saline, metallic, and carbonic matter. These orders 
