The Republican. [volume] (Oakland, Md.) 1877-current, 1881-12-17
Lime and Limestone.


Considerable interest is lust now
manifested in regard to ground raw
limestone as fertilizer. 1t is claim
ed that it is equally effective as lime.
and some remarkable statesments
have been made as to the results in
the shape flarge crops grown by its
use. Now while I.have no reason to
doubt the truth of these statements,
and do not profess to impugn them
in the least, yet it is right that some
one should explain TO your readers
why raw limestone cannot possibly
be as effective as lime, or even as
all -slaked lime, unless the latter has
been exposed for sufficient time to
have completely lost its causticity
and become thoroughly carbonated
again. Limestone is carbonate of
lime, and is ;nsouble in water unless
the latter contains some carbonic acid,
when it is only slightly soluble. But
as all water in the sol takes up some
carbonic acid from decaying vegetable
matter into solution, limestone is
nearly always dissolved to a small
extent in the water efficient at least
to make the water hard, or refuse to
dissolve soap. When limestone is
burned, the carbonic acid contained
in it is driven off, the stone losing
nine-twentieths or 45 per cent. OF its
weight. The lime is an acid, burning,
caustic substance which. has some
peculiar properties upon which its
agricultural value depends. These
are, first. that it has great affinity
for carbonic acid. great eagerness to
recover what it has lost, and to return
to is first and stable condition again.
Second, that it has also a great avidity
for water of which it will absorb
about one-third of it's weight, and
yet remain perfectly dry. Third,
that in thus absorbing water it falls
to an exceedingly fine powder, by
which its action upon organic sub.
stances is greatly assisted. Its then
called 'air slaked," as this water is
absorbed from the atmosphere.
Fourth, that in this condition it is
soluble in 700 times its vaIume of
water, and when thus dissolved its
chemical action is still further assist
ed. Fifth, that caustic lime exerts
very active decomposing effect upon
organic matter, depriving it of car
bonic acid and nitrogen, absorbing
the one and driving off the other, or
entering into some complicated com.
binations with it, and in effect rapidly
reducing it to final decomposition
and its mineral elements. 81 D.,
that it also has the property
solying silica, and thus freeingpo 4
from its combination as silicate of
potash in the soil, and leaving it free
to be dissolved in water and taken
up as food by the roots of plants.
Lastly, it exerts favorable effect
upon both clay and sandy soils, loos-
ening the one and compatcing the
other in texture, both mechanically,
and by its chemical action.
Now these most important effects
of lime give 1T very great value,
and render it one of the most indis-
pensable aids to the farmer. But on
the other hand, limestone, being
chemically inert and only slightly
soluble, can have but a very feeble
effect, If any and as must be observ-
ed, none at all where the soil is al
ready charged with lime while lime
by its varied chemical action has as
great an effect upon limestone soils
as upon peaty, mucky or alluvial
soils. Some confusion of ideas exists
in regard to the term air slaked.
This really means that the lime has
been exposed to the moist air un-
til it has absorbed sufficient water to
fall to fine powder and became hy-
i drate of lime. But this hydrated
lime is still caustic, and retains all
its chemical activity. unless the ex-