American citizen. [volume] (Butler, Butler County, Pa.) 1863-1872, 1866-12-26
farmeraa department
Patent Office Report, 1853.
Calcareous Manures.
BI-cARBoNATB OF, LIME
CONTINUED


a double proportion of carbonic acid
pas. in which state it is called a b.
corBonate, and to certain extent Is
readily soluble in water. Hence,
springs are often impregnated with
it. and the waters that gush from hs-
sures in lime ro>ks, distribute it thro'
the soil in their neighborhood, which
is a mode Nature very frequently
ado It's in fertilizing the earth. Here
let it be remembered that carbonate
of lime, though insoluble in pure wa
ter, may be dissolved to a considera-
BILE extent in that which is impregna-
ted with carbonic acid gas; and that,
when it holds lime in this way, and
is exposed to the air for length of
time. or is heated over the fire, the
lime will again separate from it more
or less completely. In this manner
stalactites are formed in caves sub
stances are petrifed in lakes and
streaus; beds of mari, in some ca
ses, are produced; drains are often
choked up with lime; and crusts are
deposited at the bottoms of kettles
and steam-boilers.
Limestones, however, are seldom
pure. They always contain a con-
siderable quantity ef other earthly
matter, chiefly silica, alumina, mag
ne ia, and oxyd of iron, with a trace
of phosphate of lime, sometimes of
potash and soda, and often of animal
and other organic remains. In lime
stones of the best quality, the foreign
earthly matter, or impurity, does not
exceed per cent. of the whole, while
it Is often much less. The chalk and
mountain limestones are generally of
this kind. In those of inferior quail
ity, it may amount to II or 20 per
cent. while many calcarsous beds
are met with in which the proportion
Of lime is go small, that they will not
burn into agricultural or ordinary
building lime, refusing to slake, OF
fall to powder, when moistened with
water. Quieklime, of course, will
contain less amount of lime in pro
portion to the superiority of the lime
stone fr0ra which it has been burned
When the carbonate of lime, which
is contained in marble, common lime
stone, or in the shells of oysters and
other shell fish, is exposed to high
temperature, in the open air, the car
bonic acid they hold, in combination
with other ingredients, is driven of
by the heat, and the lime remains
behind in caustic state. They are
decomposed more readily when a cur
rent of moist ar is allowed to pass
through the burning mas. Hence
on a large scale, this process is per-
formed in kilns. A ton 1900 lbs. y,
of good limestone yields 1,126 lbs
Of caustic lime, the weight of which
per bushel varies with the kind OF
stone employed, and with the manner
in which it is burned. In some vari
cites of lime. bushel does not weigh
more than Is pounds; while in 9th
ers, it will wei2h nearly or quite 10C
pounds. This difference shows how
uncertain the quantity of lime ap.
piled to the land may be when it j.
estimated by the bushel. Therefore
it should ae bought and applied by
weight.
The following table by professor
Johnston exhibits the chemical chan
gos which ton (2,24O pounds) oI
pure limestone undergoes, and the
relative proportion in which the sew
eral compounds exist in it after il
has been burned, slaked: and then ex
posed to the air, or mixed with the
soil -