Cheraw gazette. [volume] (Cheraw, S.C.) 1835-1838, 1836-06-28

change is produced in its chemical charac-
terS.
Lime is familiarly known by the same
name that is generally used by chemists.
1t is obtained by the aid Of heat from rocks
which 20 by the name Of limestones.
These are combinations OF lime with car.
bonic acid, which is fixed in them by chem.
icaI attraction, but which, when driven oti
by heat, takes the same form as the air OF
the atmosphere, or becomes gas. Inns
gas from this circumstance has been called
fired air, by which name it is often known
when causing the sparkling and froth OF
cider and beer. The principal part OF lime
stone is therefore called by chemists carbon.
ate of lime. Carbonate of lime is also found
in shells, both those Of living animals and
those which exist in the ground in a fossil
state. In the former it is mixed with animal
matter whicE is more or less separated since
the death of the shell fish.
Mari, in the sense in which the term Is
used by chemists, is mixture OF clay with
carbonate oflime. The English writers on
agriculture have not observed this dlstlnc-
ton, and the term is sometimes applied by
them to a decomposed chalk, which may
contain little or no clay: and sometimes to
clay which contains no carbonate OF lime:
In fact, the name is frequently applied by
them to any earthly matter found below the
vegetable soil, which is capable of !ncreas-
ing its fertility. From this smsapprehenslon,.
the substances which 90 by the name or
mari in New Jersey, Maryland, and Vrgl,
nia, do not correspond with the chemical
definition, but are generally beds OF fossil
shells mixed i'll various proportions with
carthy and saline matters of various kinds.
Lime is a substance very different in its
characters from the two earths OF which we
have previously spoken. When prepared,
by heat from any of the original forms OF
its carbonate, it retains their shape unaltered,
but may have its color changed, and always
loses considerable in weight. 1t is now
acrid, caustic and corrosive, and alkaline.
Of these the most important is, that it unltes
with acids to form compounds included IN
| the general class of salts. Of the salts OF
lime which are important to the farmer, the
three principal are: the carbonate, which,
as we have stated, is found in limestone,
chalk, and mari the sulphats, in which lime
is combined with sulphuric acid, and which
in combination with water is the substance
so well known TO our farmers under the
name of plaster of Paris, or less tamlliarly
bv that Of gypsum; the phosphate, which
constitutes part of the bone OF animals.
Lime, when exposed to the air, attracts
carbonic acid, which is always to be found
in the atmosphere; it thus passes back to
the state of carbonate, but in so doing gra.
dually falls to powder, and is then said to be
air-slaked. If slaked with water, it also
falls to powder, which still retains the
caustic character Of the burnt lime ; but this
powder, when exposed to the alr, unltes with
carbonic acid more rapidly than when in
mass. -
Lime, in its caustic state, has the proper
ty of rapidly decomposing vegetable and
animal substances, thus Fastening the na-
tural processes by which they are finally
destroyed or, to speak more properly, have
their elements resolved into new combma.
tons. The offensive and unwholsome gases
which are given out by this composition,
are absorbed by the lime, and probably by
its other compounds but in order that either
this earth or its compounds shall manifest
this property, they must be in small trag'
ments, or, which is better, in fine powder.
Wet sand and plastic clay, and those soils
to which they give their characters, also
possess the property of absorbing gasses
but they have this in very inferior degree
to lime and its compounds. AS the gases
generated by the decomposition ofvegetable
and animal substances form a large.part o.
the necessary food of plants, it is obvious
that a soil which contains the carbonate o
lime, may retain and store them up for use
while they will be lost in soils Of a ditferen
character.
Carbonate of lime may also be made
most important article in the preservation
of the most valuable parts Of putrescen
manures, until they can be applied to th'
soil. In this way mari is applied to
great extent in China the night soil o
their numerous population is there forme'
into cakes like bricks, with mari, and thu
loses its offensive smell; but when thes'
are applied as manure to the land, the.
give out the gases again as they are re
Guired for the nourishment Of plants. 81
also in Norfolk, the site for dunghllls
prepared by a layer of mari, which is in
corporated with the manure from time t
time, and retains the gases which woul'
otherwise be lost.
= Lime NAV therefore be applied in 1T
oous,;c rnrno in some cases in agriculture