94 
THE COTTAGE GARDENER. 
the carrot, scorzonera, and radish are placed in water, 
some with only their extremities immersed, and others 
with their entire surfaces plunged in, except the extremi¬ 
ties, the former imbibe the water rapidly, and the plants 
continue vegetating; but the others imbibe no percep¬ 
tible quantity, and speedily wither. It suggests also the 
reason why the gardener, in applying water or manure 
to trees or shrubs, does so at a distance from their 
stems. A good rule for ascertaining the proper distance 
for such applications, seems to be to make them beneath 
the circumference of the head of the tree; for, as M. 
De Candolle observed, there is usually a relation between 
that and the length of the roots, so that the rain falling 
upon the foilage is poured off most abundantly at the 
distance most desirable for reaching the extremities of 
the roots. 
This explains why the fibrous points of roots are 
usually annually renewed, and the caudex (or main limb 
of the root) extended in length: by these means they 
each year shoot forth into a fresh soil, always changing 
their direction to where most food is to be obtained. If 
the extremity of a root is cut off, it ceases to increase in 
length, but enlarges its circle of extension by lateral 
shoots. 
The distance to which the roots of a plant extend is 
much greater than is usually imagined; and one reason 
of the stunted growth of plants in a poor soil is, that 
the sap collected and elaborated by them has to be ex¬ 
pended in the extension of the roots, which have to be 
larger in proportion as the pasturage near home is 
scanty. An acorn accidentally deposited on a wall pro¬ 
duced a young oak; but this made no progress until its 
root had descended the whole height of the wall, and 
had penetrated the soil at its base. 
In deep, poor siliceous soils we have traced the roots 
of trees from twelve to fourteen feet perpendicular with¬ 
out reaching their termination. Those of the Canada 
thistle, seven feet; common fern, eight feet; wheat, 
thirty inches; oats, twenty-four inches; potatoes, eighteen 
inches; onions, twenty inches; carrots, parsnips, and 
beet, two feet. The distance to which roots will travel, 
and their tenacity of life, render them often very ob¬ 
noxious to the gardener. Thus the commou couch grass 
(Tritioum repens) is the most troublesome of weeds, for 
every fragment of its far-spreading roots will vegetate; 
and the sweet-scented coltsfoot and lemon mint are not 
less to be avoided, for the same cause renders them ex. 
tremely difficult of extirpation, and they never can be 
kept within moderate bounds. Yet these creeping rooted 
J plants are not to be condemned without exception; for 
whoever has grounds under his care bordering upon the 
sea-sliore, the sands of which are troublesomely light and 
shifting, may have them effectually bound down by 
inoculating them with slips of the root of these grasses 
Ehjmus arenarius, Carex arenaria, and A r undo armaria. 
The roots of plants, unless frozen, are constantly im¬ 
bibing nourishment, and even developing parts; for if 
the roots of trees planted during the winter be examined 
after an interval of a few weeks, they will be found to 
have emitted fresh radicles. 
[November 11 . 
It is by their extremities, then, that roots imbibe food; j 
but the orifices of these are so minute, that they can 
only admit such as is in a state of solution. Carbon, i 
reduced to an impalpable powder, being insoluble in ■ 
water, though offered to the roots of several plants, j 
mingled with that fluid, has never been observed to be | 
absorbed by them; yet it is one of their chief con¬ 
stituents, and is readily absorbed in any combination 
which renders it fluid. 
Roots then must obtain from a soil nourishment to 
plants in a gaseous or liquid state: we may next, there¬ 
fore, consider what constituents of soils are capable of 
being presented in such forms. Water can be the only 
solvent employed; indeed, so essential is this liquid 
itself, that no plant can exist where it is entirely absent; 
and, on the other hand, many will exist with their roots 
in vessels containing nothing but distilled water. Plants 
with a broad surface of leaves as mint, beans, &c., we 
have always found increase in carbonaceous matter, 
whilst thus vegetating; but onions, hyacinths, &c., with 
small surfaces of foliage, we, as invariably, have found to 
decrease in solid matters. The first, at all times, obtain 
nourishment by decomposing the carbonic acid gas of 
the atmosphere: the latter do so in a much smaller pro¬ 
portion: hence the reason why the latter are so much 
more impoverishing crops than the former, inasmuch as 
that they acquire nearly all their solid matter by means 
of their roots. These observations explain the conflict¬ 
ing statements of Saussure and Hassenfratz on this 
point: the former experimented with broad-leaved 
plants; the latter on such as have small foliage. The 
first maintained that plants increase in solid content 
when their roots are supplied with water only; the 
latter denied the fact. 
We took occasion more than once lately to urge upon 
our readers the importance of gas refuse as a fertilizer. 
It may usually be had at a rate so reasonable as to be 
almost the cheapest of manures, and we are therefore 
extremely pleased to receive from a correspondent at 
Crewe, in Cheshire, the following evidence confirmatory 
of our own: this letter is dated October 29th, 1850 :— 
“ A short time ago, having occasion to make inquiry re¬ 
specting Mr. Payne’s Cottage Hives, I intimated that I was 
trying an experiment with gas lime for a crop of wheat, 
promising to give you the result. 
“ The land is three rods under half a statute acre ; light 
loam; and for the last twenty years has been cropped with 
one half potatoes, the other portion Swede turnips and 
mangold wurtzel, slightly manured; the following year 
wheat, and so on in succession. The crop of potatoes, &c., 
last year was very poor, the soil being quite worn out. I put 
on this half acre 30 cwt. of gas lime, fresh from the purifiers 
of the gas works, so strong in ammoniacal salts, that the men 
had frequently to desist both in loading and spreading it on 
the land, declaring, ‘ they had never met with so strong a 
smelling bottle.' With one six-inch furrow I turned the gas 
lime under, then sowed the wheat, passing over a light har¬ 
row; my neighbours affirming that every grain would be 
destroyed!! The plant soon made its appearance, contmued 
strong all the winter, and a most luxuriant dark-green 
through the summer; running too much into the straw to 
permit its standing against strong wind and rain. 
“ I have now thrashed and measured an excellent sample of 
twenty measures of wheat (38 quarts each), from less than 
