Southern planter - The W&M Digital Archive

1859.] THE SOUTHERN PLANTER 389
bonic acid, the vapor of water, (races of
ammonia, and of nitric acid. A young
plant, placed in the free atmosphere, and
exposed to the light of the sun, gradually
increases in size and weight, and receives
carbon constantly from the corbonio acid of
the air, which is decomposed, and evolves
the liberated oxygen. The power by which
this decomposition is produced is now known
to be due to the solar ray, which consists of
a peculiar impulse, or vibration, propagated
from the distant sun, through a medium
filling all space.
It is a principle of nature, that power is
always absorbed in producing a change in
matter. This change may be permanent,
or it may be of such a character, as to reproduce
the power which was expended in
effecting it. * * * For example, the effect of
the impulse from the sun is to decompose the
carbonic acid which surrounds the leaf of
the plant, or, in other words, to overcome
the natural attraction between the carbon
and the oxygen of which the acid is composed
; and, in this effort, the motions of
the atoms of the etherial medium are them-
selves stopped. The power, however, in
this case, is not permanently neutralised
for, when the plant is consumed, either by
rapid combustion or by slow decay ; that is,
when the carbon and the oxygen are again
suffered to rush into union, to form carbonic
acid—the same amount of power is evolved
in the form of light, heat, or nervous force,
which was absorbed in the original compo-
sition. If the plant, moreover, be consumed
in the animal, the same power is expended
in building up the organization, in
producing locomotion and the incessant ac-
tion of the heart, and the other involuntary
movements necessary to the vital process.
Plants are, therefore, the recipients of
the power of the sun-beam. They transfer
this power to the animal, and the animal
again returns it to celestial space, whence it
emanated. Properly to so direct this power
of the sun-beam, that no part of it may run
to waste, or be unproductive of economical
results, it is essential that we know some-
ell expended in
exclusive devotion to this one subject. The
researches which have been made, in regard
to it, have developed the fact, that the im-
pulses from the sun are of, at least, four dif-
ferent characters, namely, the lighting im-
pulse, the heating impulse, the chemical
impulse, and the phosphorogenic impulse;
and it has further been ascertained that,
though each of these impulses may produce
an effect on the plant, the decomposition of
the carbonic acid is mainly due to the chem-
ical action. A scries of experiments is required
to determine the various conditions
uriuYr which these impulses from the sun
may be turned to the greatest amount of
economical use, and what modifications they
may demand, in order to the growth of peculiar
plants. The fact has not yet been
clearly ascertained, whether some of these
emanations cannot be excluded with beneficial
result, or, in other words, whether they
do not produce an antagonistic effect, and
what relative proportions of them are absorbed
by the atmosphere, or reflected from
our planet, without reaching the earth, by
the floating clouds of the air. To determine
these, requires a series of elaborate
experiments ancf accurate observations. We
have said that the chemical vibration is that
which principally decomposes the earbonic
acid, in the growth of the plant; but we
know that the heating impulse is an auxiliary
to this, and that heat and moisture are
essential elements in the growth of vegetation.
The small amount of knowledge we
already possess of the character of the em-
anations from the sun, has been turned to
admirable account in horticulture. In this
branch of husbandry, we seek, even more
than in agriculture, to modify the processes
of nature; to cultivate the plants of the
torrid zone amid the chilling winds of the
northern temperate zone; and to render the
climate of sterile portions of the earth congenial
to the luxurious productions of more
iavored regions. We seek to produce artificial
atmospheres, and to so temper the im-
pulses from the sun, that the effects of va-
riations in latitude, and the rigor of the
climate, may be obviated.
From all that has been said, therefore, it
will be evident, that the hopes of the future,
thing of its nature; and the lifetime cfj
labor of many individuals, supported at
public expense, would be w
(
T
in regard to agriculture, principally rest
upon the advance of abstract science—not
upon the mere accumulation of facts, of
which the connexion and dependence are unknown,
but upon a definite conception of the
general principles of which these facts are
the result. All the phenomena of the atmosphere
should be studied and traced to
the laws on which they depend. The labor
bestowed upon investigations of this kind is