ucceed, it indeed
ceases to be applicable to a second or third place in the immediate
neighbourhood. How large a capital, and how much power, are wasted
in these experiments! Very different, and far more secure, is the
path indicated by SCIENCE; it exposes us to no danger of failing,
but, on the contrary, it furnishes us with every guarantee of
success. If the cause of failure--of barrenness in the soil for one
or two plants--has been discovered, means to remedy it may readily
be found.

The most exact observations prove that the method of cultivation
must vary with the geognostical condition of the subsoil. In basalt,
graywacke, porphyry, sandstone, limestone, &c., are certain elements
indispensable to the growth of plants, and the presence of which
renders them fertile. This fully explains the difference in the
necessary methods of culture for different places; since it is
obvious that the essential elements of the soil must vary with the
varieties of composition of the rocks, from the disintegration of
which they originated.

Wheat, clover, turnips, for example, each require certain elements
from the soil; they will not flourish where the appropriate elements
are absent. Science teaches us what elements are essential to every
species of plants by an analysis of their ashes. If therefore a soil
is found wanting in any of those elements, we discover at once the
cause of its barrenness, and its removal may now be readily
accomplished.

The empiric attributes all his success to the mechanical operations
of agriculture; he experiences and recognises their value, without
inquiring what are the causes of their utility, their mode of
action: and yet this scientific knowledge is of the highest
importance for regulating the application of power and the
expenditure of capital,--for insuring its economical expenditure and
the prevention of waste. Can it be imagined that the mere passing of
the ploughshare or the harrow through the soil--the mere contact of
the iron--can impart fertility miraculously? Nobody, perhaps,
seriously entertains such an opinion. Nevertheless, the modus
operandi of these mechanical operations is by no means generally
understood. The fact is quite certain, that careful ploughing exerts
the most favourable influence: the surface is thus mechanically
divided, changed, increased, and renovated; but the ploughing is
only auxiliary to the end sought.

In the effects of time, in what in Agriculture are t