convenience, we will call artificial manures, are
threefold. First, portability: they can be easily
applied to a crop, either by the drill, or broadcast,
as a top dressing; and they can be
economically carried to districts where little
farm-yard manure is made, and where, from the
steep character of the ground, carting manure
is too costly. Next, they supply a stimulant
in an active concentrated form, which secures,
at important periods and to the very place
wanted, rapid vegetation; and, lastly, they
induce farmers to study and adapt the
cultivation of their farms to the character of the
soil.

It was soon found that artificial manures
were wasted when applied on undrained,
ill-cultivated soils. It did not suit farmers to have
a manure for which they had paid eight or ten
pounds a ton in hard cash washed away from
the undrained surface by the first heavy shower;
thus, the sale of artificial manures stimulated
the extension of thorough drainage. It was
also found that a thorough trituration of the
soil was essential to produce the utmost benefit
from artificial manures. Clean cultivation was
an obvious part of farm economy, because it
would not pay to grow weeds with manure that
cost money. Artificial manure, by introducing
the farmer to the chemist, had another effect, it
taught him to study and husband the manures
he manufactured at home; that is, to consider
the effect on the manure they produced of the
food he gave his live stock.

By degrees the trade in imported and
artificial manures has become enormous. Professor
Way has recently estimated the annual
consumption of guano at from one hundred and
fifty thousand to two hundred and fifty thousand
tons, and of phosphate of lime, including
bones, at from one hundred and fifty thousand
to two hundred thousand tons; guano being
worth thirteen pounds, and super-phosphate
seven pounds, per ton.

But this vast consumption of portable
manures has in no degree checked the use of the
home-grown article, farm-yard manure; on the
contrary, it will be found that those farmers
who feed their live stock most liberally on
oil-cake, pulse, and other purchased food, and who
most carefully prepare and store farm-yard
dung, are also those who most liberally invest
in portable manures, whether ammomacal or
phosphatic. The accepted directions for growing
a first-rate crop of mangel-wurzel, are the
careful ploughing or smashing up by steam-power
of a stiff soil, the ploughing in of twenty
loads per acre of good farm-yard manure, and
the addition at sowing time of two hundred
weight per acre of a portable root manure,
principally composed of phosphate of lime, with a
slight mixture of guano. Dr. Voelcker has proved
that phosphate of lime, while so valuable an
assistant in growing roots, produces little or
no effect on stiff clay soils without deep and
complete cultivation; and he has pointed out
that, there are in this country a class of clay
soils which will grow excellent and repeated
crops of grain, if well deeply cultivated, with
little or no manure—such is the aptitude of
these soils to assimilate the vast stores of
ammonia floating in the atmosphere. It is on such
soils that steam cultivation plays an important
part.

On the general run of clay soils, the use of
solid long straw farm manure is essential in a
mechanical point of view; it helps to make the
soil loose, and reduce it, in conjunction with the
plough or the steam cultivator, to the fine tilth,
the porous disintegrated state, which is the
great object of the husbandman in northern and
weeping climates.

About the same time that purchased portable
ammoniacal and phosphatic manures were
introduced to the farmers of this country, an
exceedingly ingenious gentleman, the late Mr.
Smith of Deanston, who had in turn been a
farmer and a manufacturer, and experienced
equal ill success and displayed equally extraordinary
inventive ingenuity in both pursuits,
thought he had discovered a system which,
had it realised all his expectations, would have
been something very like agricultural perpetual
motion.

He found at Edinburgh a truly "Foul Burn,'*
which had for nearly two hundred years
conveyed the sewage of part of the city over
certain fields on the sea-shore. At the time he
made his examination, this liquid sewage, flowing
from the city on a hill, had been for
upwards of twenty years carefully conveyed on
the water-meadow system of irrigation over
several hundred acres with an admirable
result.

He found sea-sand, perfectly worthless in its
original state, converted, by sewage irrigation,
into meadows, bearing every year a series of
most luxuriant crops of natural and artificial
grass, and yielding rents of from twenty to thirty
pounds an acre.

The sight fired his sanguine imagination. He
was at that time an officer of the new board for
improving the sanitary condition of the towns
by drainage and water supply, and he believed
that he saw in agricultural use and sale of the
sewage of towns, an unfailing source of revenue,
from which the whole cost or sewers, and water
supply, parks, fountains, and other public
embellishments, might be defrayed. But as all
towns were not so fortunately placed as
Edinburgh, on a hill, and as in expectation of a
universal demand—for other crops beside grass
would require irrigation—with characteristic
ingenuity he devised a system for pumping by
steam-power where gravitation could not be
employed, and of distributing the liquid manure
through a network of subterranean pipes, worked
by a steam-engine, with hose and jet like a
fire-engine. In the absence of exact chemical
knowledge, he calculated that sewage was of about
half the strength of guano, and that clay soil
would yield to liquid sewage as bountifully as
sand. We now know that one-twentieth would
be nearer the mark.

Human excreta had been in use as manure