( 80 ) 
that of soil and climate. In the neighborhood of 
_ great cities, table vegetables are of much more val- 
ue than wheat or rye; but remote from markets, 
wheat and rye have the advantage, because being 
more valuable, in proportion to bulk and weiglit, 
they bear better the expense of transportation. 
With this general view of the subject, we pro- 
ceed to examine, Ist, the practice of Europe; and 
2d, the rotation best adapted to our own soil, meri- 
dian and markets. And, 
Ist. Of the practice of Europe : 
It was long since discovered, (1) that the soil, 
when left to itself, was never either exhausted or 
tired or idle ; but that however stripped or denuded 
by man and the animals he employs, it hastens to 
cover itself with a variety of plants, of different 
and even opposite characters ; that some of these 
have a tendency to render the earth more compact, 
while others have the effect of opening and dividing 
it—that some, (from a peculiar structure of roots, 
stems end leaves) derive most of their nourishment 
from the earth, while others, differently formed, 
draw their’s principally from the atmosphere: and 
lastly, that in these voluntary products, there is a 
continual and nearly regular succession of plants 
differently organized. ‘These observations, care- 
fully made and no longer doubted, and others lead- 
ing to the same or similar conclusions, first suggest- 
ed the usefulness of taking nature as our guide, and 
(1) Virgil, who was a philosopher as well as a poet, appears to have thoroughly 
understood this branch of natural history : “ mutatis quiescunt fatibus arva”—the 
true repose ofthe earth is in a change of its productions. 
