Baton-Rouge gazette. [volume] (Baton-Rouge, La.) 1819-1856, 1842-05-14

Now 1t was deduced from all the %foragain
facts that plants require for their growth dill
ferent constituents of soil, and it was yer
soon perceived, that an alteration of the plant
cultivated maintained the fertility of a sol
quite as well as leaving it at rest or fallow
1t Was evident that all plants must give bacl
the soil IN which they grow different proper
tions OF certain substances, which are capa
bic Ct being used as food by a succeedin!
generations.
But agriculture has hitherto never soueh
AID from chemical principles, based on thu
knowledge OF those substances, which plant,
extract from the soil on WHICH they grow
and Of those restored to the soil by means o
manure. The discovery of such principles
VIII be the task of a future generation, fol
what can be expected from the present which
recoils with seeming aistrnst and aversion
from all the means of assistance offered it by
chemistry. and which does not understand the
art OF making a rational application of chemi-
cal discoveries a future generation, how
ever, will derive incalculable advantage from
these means of help.
Of all the views which have been adopted
regarding the cause Of the favorable effects
OF the alterations Of crops, that proposed by
NJ. Decandole alone deserves to be mentioned
as resting on a firm basis.
DecandoHe supposes that the roots of plants
I'M oibe soluble matter of every kind from the
soil, and thus necessarily absorb a number of
substances which are not adapted to the pur-
poses OF nutrition, and must consequently be
expelled by the roots, and returned to the soil
as eScrements.f Now as excrements can
net be assipilated by The plant which elected
them, the more OF these matters which the
soil contains, the more unfertile must it be
tor plants OF the same species. These ex-
crementltlous matters may, however, still be
capable of assimilation by another kind of
plants, which woaidthus removs them from the
sot. and render itagaip fertile for the FIRST. And
if the plants last grown also expel substances
from their roots, which can bs appropriated
as food by the former, they improve the spil
in two ways.
Now a great humber offfacts appear at first
sight to give a high degree of probability to
this view. Every gardener knows that a
fruit-tree cannot be made to grow on the same
spot where another of the same species has
stood ; at least not Until after a lapse of sere-
raj years. Before new vine-stocks are plant
ed in a vineyard from which the old have
rooted out, other plants are cultivated on the
soil for several years. In connection with
this it has been observed, that several plants
thrive best when growing beside one anoth-
er and on the contrary, that others mutually
prevent each others development. Whence
it was concluded, that the beneficial influence
in the former case depended on mutual in
terchange of nutriment between the plants,
and the injurious one in the latter on a poi
sonous action of the excrements of each on
the other respectively.t
A series OF experiments by Macaire- Prin-
cep gave great weight to this theory. He
proved beyond all doubt that many plants are
Of emitting e3tractiye matter from
their roots. He found that the excretions
were greater during the night than by day(e),
and that the water in which plants of the fa-l
mily Of the Leguminosc grew. acquired a
brown color. Plants of the same species
placed in'water impregnated with these ex-
crements, were impeded in their growth, and
faded prematurely,. whilst on the contrary,
,orn- plants grew vigorously in it, and the CO.
or of the wa1er diminished sensibly :; SO that
t appeared, as if a certain quantity of the ex-
of the Leguminosc had really been
described by the complaints. These expert
nents afforded as their main result, hat the
and properties of the e%xcrements
# different species of plants are different from
ne another, and that some plants expel excre-
nentitious matter ofan acrid and r~esinous char
cter; others mild (douce) substances resem-
ling gum. The former of these, according
o Macaire-P rnacep, may be regarded as poi
onons, the latter as nutritious.
The experiments of Macaire- Princep are
proof that the roots, probably of all
lants, expel matters, which cannot be con-
erted in their organism either into woody f.
re, starch, vegetable albumen, or gluten,
ince their expulsion indicates that they are
ute untitled for this purpose. But they
annot be considered as a confirmation of the
heory of DecandoKs, for theydeave it quite
.ndecided whether the substances were ex-
racted from the soil, or formed by the
liant itself from food received from another
ource. 1t is certain that the gummy and
esinous excrements observed by Macaire
'rincep could not have been contained in
ne soil; and as we know that the carbon of
soil is not diminished by culture, but, on
contrary, increased, we must conclude,
nat all excrements which contain carbon
aust be formed from the food obtained By
from the atmosphere. Now, these
are compounds, produced in
onsequenceof the transformations Of the
BOD, and of the new forms which it assumes
y entering into the composition Of the va
organs.
NJ DecandoAe's theory is proper y a mo-.
of an earlier hypothesis, which
opposed that the roots of different plants
different nutritiFe substances.
the soil, each plant selecting that
hich was exactly suited for its assimila-
on. According to this hypothesis, the
latters incapable of assimilation are not
from the soil, whilst II. Decen-
ole considers that they are returned to il
the form of e~xcrenneats. Both views
how it happens that after corn, corn
annot be raised with advantage, MOI after
cas-, but they do not explain how a 6eldl
improved by lying faliow, and this in j;
roportion to the care with which it is til +,
d and kept free from weeds; nor do they i
low how a soil gains c~arbonaceoas matter
-~---- :
. 1t has been observed, for instance, that if :
plant is placed in sand moistend with dilu- :
d water, the roots disengage, during the J
ght little drops of some fluid, which, after I
time, conefets into a solid form. t
THAT these surpassed esudations are
more or less injurious to plants j
similar species, cas- been inferred from !
e fact, that a soil, in which peach or ap. !
. trees have grown, is unfit for young t
loots. of the same description, so as to rem !,