Year: 1859

We can then by an examination of the fixed
principles contained in the ashes of vegetables
determine the nature of the earth proper to
the various species of plants likewise, we can
know the chemical composition of useful prin-
cpleS, which We should seek there and be
able to distribute properly the humus which
yields carbon, and the manure muck which
produces azote or nitrogen. Let US give some
examples-The straw of wheat contains sill
cate Of potassa, and the grain. phosphates of
potasSa, lime and mag neSia. Earth the most
abundantly provided with manure and humus
shall then give sorry harvest if the substan-
ces above name exist not properly commin-
gled with the soil. We say properly commin-
gled, for if We there find only small quantity
of the phosphates, and the silicates predomi-
nate, We shall have harvest rich in straw but
poor in grain; if the silicates and phosphates
wanting we shall have many leaves and a
fine flexible straw like that of which they make
Italian (Leghorn) hats if the ground contain
only cacareOus matter or sand, the wheat har-
vest will be nothing, because the potash ne
cessary to the growth of the plant is wanting;
but if, on the contrary, to the silicates and
phosphates of the alkalies, ammonia is Joined,
then the harvest will be perfect-witheut hu-
mus being necessary, for the atmosphers is an
inexhauseable reservoir of carbonic acid.


The potato yields almost one seventh of its
weight in alkaline ashes, whilst wheat furnish
es less than twentieth. The same earth, then,





the potato is cultivated in soil rich in hu-
mus (Which is not indispensable for wheat) the
carbonic acid furnished by the humus favors
the development of fecula or starch If, on
the other hand, the ground is provided with
dung, this nitrOgenous manure augments the
proportion of albumen and of cellular tissue,
and renders the tubers soapy and much less
nutritious. The same observation applies to
turnips. Beets also yield more sugar in soil
analogous to that which the potato demands.


Oak wood furnishes in alkaline ashes one
fortieth of its weight, and the leaves one twen-
tieth /; the frs give less than a hundredth and
their leaves are ten times less rich in potash
than those of tho oak. Behold why limestone
and sandy soils, poor in alkahes, produce on
ly some green trees; whilst those which con-
tain feispar, gneiss, granite, basalt and other
siicates, produce the most beautiful forests
of oaks and other large leaved trees.


The ashes of vegetables always contain phos-
phates of potassa, lime and magnesia, especi-
ally those of the seeds of the cereals and le-
gumes, and We know that in the animal king
dom, phosphate of lime constitutes the solid
part OF bone. This striking agreement which
forms one more bond between the two king
doms, shows that the presence of phosphate
of lime Is condition, indispensable, to the
existence as well of vegetables as of animals.


From all the facts which have come to light
we must conclude that the various vegetables,
require in the soil, certain mineral substances
without which they cannot prosper. The ex-
animation of vegetable ashes discIoses their
presence there, and if the soil, where we wish
to cultivate those vegetables, does not contain
like mineral substances (Which can be verified
by anaiysis) the cause of its steriiity becomes
known and the means of remedying it also.