December i, 1881.] 
THE TROPICAL AGRICULTURIST. 
56i 
HOR/E HORTULAN7E : — ON SOILS. 
(Gardener*' Chronicle, 24th September 1881.) 
(Continued from page 476.) 
The fundamental difference between live and dead 
soils, as alluded to in the last article, entails many other 
secondary differences, and of these perhaps the most 
important are what we may sp 
as physical 
be, or favoured by this or that particular chemical con- 
stitution, and not the direct consequence of the pre- 
sence of this or that chemical substance. But over and 
above chemical constitution, to which I will return 
presently, every gardener will admit that the physical 
characters of a soil are of prime importance. These 
may be roughly classed under three beads— cohesion, 
which determines whether the soil be stiff, or friable 
and loose ; moisture ; and behaviour towards radiant heat, 
cold'!' 6 ° ^ Ut ' 1 
Iu respect of cohesion, extremes are seen in the stiff 
clay which the mattock can cut out in almost perfect 
cubes, and the light sand which is in danger of being 
blown away by every gale of wind. Each of these, 
viewed from the simple physical point of view, has its 
advantages : the stiff clay affords anchorage for stout 
and long thong-like roots, the loose sand favours the 
wanderings of tiny tlu-ead-like rootlets. And though it 
cannot lie denied that the nature of some plants leads 
them to flourish best in a stiff soil, while others refuse 
to grow in other than a looso one, the soil which is 
most satisfactory for the gardener, the one which he 
can clothe most abundantly with the choicest and most 
varied flowers, is a " mean " soil, one which is neither 
stiff nor loose, or, to speak more truly, which is at the 
same time both stiff and loose. This indeed is recog- 
nised in the usual directions of gardening books, where 
we aro told to lighten the stiff soils, and to give body 
to the light ones ; but— and this is the point to which 
I wish to call attention— it does not seem always kept 
in sight, that the most suitable degree of cohesion, the 
and caked, which is porous, and yet lies undTsturbed 
by the fiercest winds, is one of the most precious attrib- 
utes of "live" soil, 'is one of the results of the fer- 
ment actions of which I have spoken. 
Many of us, I suppose, have taken in hand a patch 
■of dead stiff uncompromising clay. Sticky, buttery, 
clammy all the whiter, baked to a hard, rough, brick- 
like cake in the summer drought, it was at first our 
despair. As, however, season after season we dug into 
it a good body of rich farmyard manure and turned it 
over and over, it changed its nature, and mellowed into 
a rich " live " loam. That change was not merely the 
result of a mingling 0 f the particles of decayed straw 
and .lung with the particles of the merely divided but 
otherwise unaltered clay — was not merely due to tlio 
addition of ammonia, potash, phosphates, sulphates, and 
(be like, to the alumina basis of the clay — was not 
wrought alone by the burrowing rodent action of the 
numberless rootlets of the plants we from time to time 
gu n in it -it was not solely brought about by the 
cleaving might of winter's frosts, which split the ragged 
lumps into Crumbling powder; it was not tin- work of 
Bach of these, of all these alone, though every one in 
turn helped. More potent than any of them, though 
working with and through each of them, was the action 
of the ferments, of which the stable-yard manure was 
at onre the source ami seed-bed. These attacked the 
stiffness of the clay at its very source, altering the 
chemical combinations on which the molecular stil m ■ 
hung deep; these not onlv mixed but united the salts 
Ml 
I and carbon compounds of the manure with the aluminic 
base, and thus digested at first the incongruous factors 
into a uniform whole. And their work was a lasting 
one, whereas the crumbling powder which the winter's 
frost leaves, if it be the work of frost alone, is soon 
battered back again by the rains of spring into a cakey 
lump ; the clay once worked up into " live " soil can 
never go back to its native stiffness. 
The case of sand is somewhat different, since the 
silica of sand does not lend itself so readily as the 
alumina of clay to chemical transformation ; to convert 
pure sand into a wholesome soil some distinct " body " 
must be added in mass. But here, too, the subtle in- 
fluence of ferments may be seen. If you mix pure sand 
with pure clay, even though you pour into it abund- 
antly solutions of ammonia and all necessary salts, the 
result will be simply an indescribable medley fit for no 
man's land — a muddle, which after a while will resolve 
itself back again into clay and sand. Work into the 
same mixture an adequate supply of organic stuff, either 
itself holding ferments or serving as material with which 
ferments can work, be it stable manure, peat, or leaf- 
mould, and in a short time clay and sand will be blended 
into a profitable nutritious mould. 
Everywhere,- indeed, we may see the same thing, the 
hidden slow subterranean work of fermentative organic 
matters, aided by rain, sun, and frost, converting the 
too tenacious, or the too fugitive native sterile dead 
earth into porous and yet consistent fertile live soil. 
And this medium soil is assuredly the best for most, if 
not for all plants. I do not pretend to understand the 
mystery why some plants love a light and others a 
heavy soil, but there are reasons for thinking that the 
long stretching roots, which are almost characteristic of 
tho latter class, serve rather for anchorage or for the 
gathering in of adequate moisture than for the seizure 
of actual food. At all events, these long, bare, whip- 
like roots are accompanied by masses of matted fibrous 
rootlets, which, running into the generous superficial 
mould, seem specially adapted for assisting the plant 
to obtain more copious nourishment. And whenever such 
rootlets are present, access to a rich, friable, lively 
earth is sure to bring healthy foliage and an abundant 
bloom. 
Important as is this attribute of live earth, whereby 
its spongy yet firm nature affords the best bed for the 
continual spreading of the tender, tiny rootlets, still 
more important perhaps are the relations of the same 
thoroughly digested soil to moisture. If there be one 
thing which is above all others the gardener's one anxious 
care, it is to see that the plants shall have enough, and 
not more than enough, water. Out-of-doors we are 
lifted with hope or filled with despair according as the 
rain falls at the right time and hi proper measure. In 
the greenhouse the one question which repeats itself in 
worrying fasliion day after day is — " Shall I give this 
plant more water or no ? " The ignorant, clumsy gard- 
ener is known at once by liis manner of watering, and 
where mistakes in soil, or pots, or pruning have killed 
their thousands, mistakes with the watering-can have 
killed then' tens of thousands. " Let ino have day by 
day just as much water as I need, so that I am never 
dry and never water-logged ! " cries nearly every grow- 
ing plant, and in hundreds of glasshouses throughout 
the land many a wretched flower is being baked when 
it should bo moist, and drenched when it should be 
barely damp. One feature of " live " earth is that it 
does its best to remedy the fitfulness of outdoor wea- 
ther and the errors of indoor ignorance. This is very 
clearly shown by a valuable experiment of Luwes ami 
Gilbort. These gentlemen laid down a series of parallel 
deep drains in a long sloping field, at the bottom of 
which each drain opened into a reservoir, so that the 
amount of water passing along each drain could be 
measured. Part of the field was either left alone or 
treated with saline matters only; part was well dressed 
