362 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ October 25, 1883. 
north. Mr. Brunton prunes so as to always have plenty of young wood, 
three and four shoots coming away from one “ spur,” if we may so term 
the growths annually left. The border is watered three weeks before the 
Vines are started, and receives no more till the time to start the Vines 
arrives the following year. A dressing of manure 1 foot thick is placed 
over the border when it has been watered, and which is not removed for 
twelve months. On the outside border a thick dressing of manure is 
placed at the beginning of each winter. The border is filled with a thick 
network of roots close up to the surface. The borders themselves were 
made in a manner rather different from the usual mode. Drainage a foot 
in thickness was first placed, then the top of the drainage was “grouted” 
with hot lime and water, and on this the soil was placed. One important 
item in the management remains to be noted—Mr. Brunton does 
everything required to the Vines himself.—B. 
GARDEN CHEMISTRY. 
SOILS. 
After the elements of which plants are composed, in importance 
we must rank the media in which they grow—the soil where the roots 
extend, and the air from which the leaves extract the bulk of vege¬ 
table substances. 
Soils vary very much in physical, but even more so in chemical 
properties. There is a great difference between a sharp sand and a 
putty-like clay, while peat differs from either. As no garden operation 
is of so much importance, and as nothing else so much determines 
the failure or success of our efforts as the choice of soils, it must be 
of great advantage to have an intimate knowledge of what constitutes 
the difference among them. On this foundation all gardening prac¬ 
tice is built, and success would be surer, while failure would oftener 
be avoided, if young men were taught what to avoid and what to 
choose in the matter of soils among their first lessons. Instead of 
groping their way, after long years of perhaps bitter experience, to the 
light, or indeed never really reaching it at all, it would then guide 
their footsteps from the first. As many of the ideas about soils are 
erroneous no apology will be offered for going rather minutely into 
this phase of garden chemistry. 
All soils, with the exception of peat, are chiefly composed of 
fragments of rocks, and if even the softest of these be viewed through 
a good double lens this fact will be apparent. Sand then seems com¬ 
posed of boulders, limestone, or chalk of shells, and even clay looks 
gritty. For practical purposes an intimate knowledge of geology is 
not necessary to a good useful knowledge of soils, although the more 
knowledge one has in that direction as in every other the better. The 
nature of any given sample is of more importance than the particular 
formation in which it was found. It is very interesting to know that 
in the coal measures the soil generally is very poor, and in the old 
red sandstone generally very fertile ; but a sample of good soil from 
over the coal deposits is for all that to be preferred to a poor one, 
though decidedly derived from the old red sandstone. In Fife some 
of the hungriest gravels occur in the district where the old red sand¬ 
stone crops out, although very good also occurs ; and over the coal 
measures—at the very spot, too, where the carboniferous strata are 
covered only by mould—good land occurs. In the long fertile tract 
known as the Carse of Falkirk and Stirling occurs land second to 
none in Scotland, yet the coal is underneath. 
To the farmer the chemical composition of soils is perhaps of 
paramount importance ; to the gardener physical properties come first. 
For both a good loam is best. To the farmer chiefly because it will 
often stand the continual drain to which it is too often subjected ; to 
the gardener because such not only suits a majority of garden plants, 
but because it holds manurial matter better than light sandy soil, and 
is more easily worked and drained, being also warmer than clay. 
These are also advantages to the farmer. 
The most common ingredients in soils are stones and sand in 
gravelly or sandy soil ; these mixed with clay in loamy soils, clay in 
clay soils ; sand, stones, clay, and lime in calcareous soils, and peat 
in bog earth. In addition humus is more or less present in all soils. 
Sand is derived from the disintegration of rocks. Take a piece 
of trap and expose it to the air in our latitude. What after a time 
happens ? It begins to decay, and we are all familiar with “ rotten 
rock.” The rain moistens it, for, compact though it may seem, it is 
porous, and water penetrates its structure. The frosts of winter 
expand this. Now the expansion of water as it becomes ice is quite 
irresistible. In this respect water differs from everything else. 
Mineral matters go on contracting the colder they get, and expanding 
the hotter they become. Water as it gets hot also expands from 
about 40° Fahr. upwards, but also from that downwards. But for 
this fact our ponds would in winter become solid ice. In freezing 
six pints of water become about seven of ice ; hence ice is lighter 
than water, and floats, forming a protection to aquatic plants and 
animals instead of proving their destruction. But this expansive 
power proves destructive to the rocks, hence they crumble and fall ; 
but the effect is chemical as well as physical. Mere mechanical force 
grinds. The expansion of frost is merely mechanical. Now a piece 
of trap may be said to be composed of felspar and hornblende, and 
pieces of trap, no matter how small, are just composed of these 
minerals ; but when triturated by the weather chemical decomposition 
comes into play. Felspar is a polybasic silicate of alumina, potash, 
soda, and tracts of other bases ; when chemical decomposition ensues 
the mineral breaks up into aluminic silicate, or clay and potassic and 
sodic silicates, &c. The aluminic silicate (clay) which forms from 
decaying felspar is very fine and soft. Hornblende, the other mineral 
in whinstone, as it is called in Scotland, contains much less alumina, 
but more silica, and as much as 10 per cent, of lime, 15 of magnesia, 
and 10^ of iron oxide. Sometimes felspar predominates in trap, 
sometimes hornblende. When the former is most plentiful a heavy 
clay soil is often formed from it very rich in potash. When horn¬ 
blende predominates in addition to the potash, lime is also, set free, 
but lime is apt to disappear. The Carse of Gowrie clay is a good 
example of a clay rich in potash, as much as per cent, being 
present in some spots—altogether a unique amount. 
Granite does not contain hornblende, but contains a large amount 
of silica with a varying amount of felspar and mica. The silica 
appears in the polished monuments, with which most of us are 
familiar, like glass, and is in the form of quartz. The grey, greenish, 
or reddish matter mixed with the quartz is felspar. Soils formed 
from granite are often by no means poor in potash, but always deficient 
in lime and other necessary mineral matters. For this reason phos¬ 
phates applied to Turnips in the far north often yield results which 
astonish those who are unaware of the cause. But most granite soils 
are very poor sands. Heavy rains wash away the fine clay, and with 
it everything else, that forms from the felspar - , and leave the poor 
sand formed from the quartz. This fine matter is transported in the 
mountain streams when in flood ; is carried down the brooks and 
rivers, and finally settles as silt in lakes or perhaps far out at sea. 
The further it is carried the finer will the matter be. The heavy 
particles settle first and form gravel; further on lighter sands form, 
then loams, and finally clays. A good example may be seen of the 
latter at present in process of formation off Grangemouth. Here 
the mud which comes from trap and granite hills, from the Ochils 
and Grampians, settles in the quiet of the Firth of Forth, causing no 
end of trouble and dredging to the harbour authorities of the upper 
parts on the estuary, and forming a large addition to the Carse of 
Falkirk, which is dry when the tide ebbs, and is, indeed, much higher 
than the cultivated lands within the dykes. 
Few soils are so simply formed as these. They are, for the most 
part, made of rocks which have originally come from the igneous rocks 
(as those of the class to which trap belongs are called), but which 
have been degraded and remade times avithout number by such means 
as we have indicated. 
By the means we have named, sandstones and clay slate and shale 
rocks have been formed. Another class exists—limestones, these 
form vast beds, and even hills and cliffs. They are familiar to us as 
chalk, marl, limestone, marble. 
Doubtless in the far back past carbonic dioxide was much more 
plentiful in the air than now. This Avhen dissolved in water—and it 
always is present in rain—becomes an acid possessing solvent powers 
on many minerals. It specially attacks lime. Hence the lime 
liberated by decaying rocks speedily becomes soluble, and is borne 
in every stream as bicarbonate of lime (calcic bicarbonate). Aquatic 
animals, many of them extremely small, separate this from the water 
and form their shells out of it, shells being carbonate of lime. Dying, 
their shells have been by ocean currents borne to sea valleys, and in 
course of long ages their accumulation has resulted in the immense 
beds with which we are familiar. In the case of corals the growth 
has been almost tree-like. Marls are just limestones which have 
been formed in the quiet of recent (geologically) fresh-water lakes. 
At the bottom of peat beds layers of shell are often found, and an 
occasional canoe. These have been formed in lakes which \ T egetation 
has since filled up. In some such Avay were the beds of limestone 
which lie under coal beds formed. 
Burnt in the open air, limestones crumble, because they are 
chemically" decomposed. Limestone is a carbonate of lime. The 
burning drives off the carbonic dioxide. Heated to a high tempera¬ 
ture in a closed vessel the stone fuses—melts. Just in this way has 
marble been formed. Eruptions of trap or lava have fused the lime¬ 
stone, practically in closed vessels, because deep under air-excluding 
superincumbent laymrs, and the result is limestone fused—marble. 
In all parts of the United Kingdom, but more especially in 
Ireland, great tracks of peat soils are formed. Peat beds are the 
remains mostly of mosses and bog grasses. They only form where 
water cannot get away, and being covered with spongy mosses on the 
surface, which not only love water but possess the power of holding 
it, and AA - hich have few soil requirements beyond water, keep dying at 
the base continually and as continually extending at the points, till 
in process of time beds of solid peat are formed, as much sometimes as 
40 feet thick. 
