194 % Bibliography. 
not formed the soil which covers them, is far too general in its terms. 
And if the preceding statements are correct, we must believe that rocks 
do sometimes affect the vegetation which covers them. We believe there 
is some truth in the common opinion, that limestone regions are more 
prolific of vegetation than any others. _How very different is the Flora 
of the trap ranges in the Connecticut valley from that of the. primary 
ranges of equal height on the sides of the valley! How different the 
oaks, maples, beeches, and hemlocks of the Hoosac mountain, from 
the chestnut groves of the Taconnic! Must not these differences be in 
part imputed to the peculiarities of the soil derived from the rocks? 
The author refers to the cultivation of the different sorts of grain on 
all soils and in all the temperate regions of the globe, as proof that 
rocks do not affect the vegetation above them. But some species of 
plants, like some species of animals, are adapted by the Creator to 
Imost all climates ; and as man is one of them, we should expect a 
beneficent Providence would give the same power to those cerealia, 
which furnish him food. But let us attempt to cultivate the numerous 
peculiar species found in particular localities in. all. places where grain 
will grow, and we should fail in nine cases out of ten, Does this argu- 
ment then from the cereals prove the point ? Would not the argument 
from the other species referred to, be equally good on the other side? 
But we have neither time nor space to say all on this subject’ samt 
as wish. 
. The fourth principle of agricultural chemistry is that ‘all soils con- 
tain enough of lime, alkali, and other inorganic elements, for any crop 
grown on them.” We are constrained to say that we could wish this 
rule also were expressed in terms less general and sweeping. Te 
prove it, the author has taken a strong case,—the soil of a barren pine 
plain. He supposes it formed of the drift of granite, which,. upon an 
average, contains seven and a half pounds of potash, and three eighths 
of a pound of lime. An acre then, six inches deep, would contain 
3626 pounds of lime, and 73311 pounds of potash. - 
Granting the premises, the conclusion is irresistible. We will admit 
that the soil of a pine plain may have been originally derived from the 
disintegration or abrasion of granite. But let almost any soil of this 
yoni be examined, and it will be found. that the feldspar and 
