257 
217 Soils, improvement of. Agriculture and horticulture are 
now seen to be entirely dependent on a code of scientific prin- 
ciples, which, time ago, were never dreamt of as necessary to 
their successful application. We should be wanting in attention 
to our readers did we not introduce to them a portion of that 
scientific knowledge which is now-a-days so greatly disturbing 
the equilibrium of old prejudices. Chemistry must lend its aid 
in the cultivation of a garden or a farm, and we doubt not but 
its application will, ere long, be brought within the reach of 
every one. Not that we expect all to become chemists, any 
more than we expect all to become lawyers or doctors ; but, 
doubtless, chemical knowledge will be brought to market just 
as is legal or medical; and the farmer or the gardener will, ere 
long, administer, according to the prescription of the chemist, 
proper remedies to the clay he cultivates, just as by the pre- 
scription of his medical man he now applies remedies to the 
clay he wears. 
Our countryman. Sir Humphry Davy, promulgated the first 
hints regarding the necessity of analyzing soils, and guiding 
agriculture by the laws of chemistry ; but it remained for 
Liebig, the celebrated Professor of chemistry in the university 
of Giessen, to make a decided advance in this department of 
science. His first work, on Agricultural Chemistry ; and his 
second, on Animal Chemistry, are eminent 'examples of acute 
research, — they are in advance of their day, which has, perhaps, 
been felt by their author; and induced him to publish a short 
series of “Familiar Letters on Chemistry,” which will command 
the attention of the learned and unlearned. That the value of 
this little work may be known, we will here extract the leading 
features of two of the Letters, relating equally to agriculture 
and horticulture. The author says : — 
“Experience in agriculture shows that the production of veget- 
ables on a given surface increases with the supply of certain 
matters, originally parts of the soil which had been taken up 
from it by plants — the excrements of man and animals. These 
are nothing more than matters derived from vegetable food, 
which, in the vital processes of animals, or after their death, 
assume again the form under which they originally existed, as 
parts of the soil. Now, we know that the atmosphere contains 
none of these substances, and therefore can replace none; and 
2'39. AUCTABIUU. 
