Cheraw gazette. [volume] (Cheraw, S.C.) 1835-1838, 1836-10-11

he 10llOWlllSS Is irOiu tllc 1>e"- Aolh Notttl@-
tor, and part of the system of British Hus-
Jandrp extracted from that Journal.-Sor'-
ern AgriculturaliSt.
OF THE DIFFERENT SPECIES OF MINERAL
HANURES.
Alkaline EarthS, or AlkahS and their
Combinations which are found unmixed with
the remains of any organized beings, are
the only substances which can with proprl-
ETY. be called fossil manures. The only
alkaline earths which have hitherto been
applied in this way, are lime aud magnesia; !;
though po.assa and soda, the two fixed al
kals, are both used to a limited extent in
certain of their chimercal compounds.
The most common form IN rtich lime IS
found on the surface of the earth, is in a
state of combination with carbonic acid or
fixed air. If a piece of limestone or chalk
be thrown inio fluid acid, there will be an
effervescence. This is owing to the es-
cape of the carbonic acid gas. The lime
becomes dissolved in the liquor. When
limestone is strongly heated, the carbonlc
acid gas is expelled, and then nothing re-
mains but the pure alkaline earth; IN this
case there is loss of earth and ifthe fire
has been very high, it approaches to one
half the weight of the stone; but in COM
mon cases, limestones, if well dried before
burning, do not lose much more than 30 or
40 per cent. or from seven to eight parts
out of twenty.
U-hen burnt lime is exposed 10 the atnaos-
phere, in certain time it becomes mild,
and is the same substance as that preclplta-
ted from lime water; it is combined with
carbonic acid gas. Quick-lime, when first
made, is caustic and burning to the tongue,
renders vegetable blues, green, ndlssolubc,
RI. e. dissolves, in water; but when COM
bined with carbonic acid, it loses all these
properties, its solubilitv, and IFS taste; 1t re-
rains its power of cffervescing, and be-
comes the same chemical substance as
chalk or limestone. Very few limestones
or ,halks consist entirely of lime and car
bonic acid. The statutary marbles, or
certain of the rhomboidal spars, are al
most the only pure species; and the
different properties of lumestones, both as
manures and cements, depend upon the
nature of the ingredients mixed with the
limestone; for the true calcareous ele-
ments, the carbonate of lime, is uniformly
the same in natare, in properties, and et-
fects, and consists Of one proportion OF car
bonic acid. Ala, and one lime, So. When
a limestone does not copiousy y etter-
vesces in acids, and is sufficiently hard to
scratch glass, it contains silicious. sandy
and probably aluminous, [clayey,] earths'
When it is deep brown or red, or strongly
coloured of any of the shades of brown OF
yellow, it contains oxide of iron. When Ii
is no, sufficiently hard to scratch glass, bu1
effervescesces slowly, and makes the acid
in which it effervesces milky, it contains
maenesia. And when it is black, and
emits a fntid smell if rubbed, it contains
coaly or bi,uminous matter. Before any
opinion can be formed of the manner III
which the different ingredients in limestone
modify their properties, it will be necessary
to consider the operation Of pure lime as a
manure.
Quick. lime in its pure state, which IN
powder or dissolved in water, is injurious
to plants. In several instances grass has
been killed by watering it with lime-water'
But lime, in its state of combination with
carbonic acid, is a useful ingredient IN
soils. Calcareous earth is found in the
ashes of the greater number of plants: and
exposed to the air, lime cannotlong continue
caustic. for the reasons that were Just no"
assigned, but soon becomes united to car
bonic acid. When newly burnt lime is cX'
posed to air, it soon falls into powder; lr
this case it is called slaked lime; and the
same effect is Immediately produced by
throwing water upon it, when 1t heats vlo,
lently, and the water disappears. Slakee
lime is merely combination Of llme' with
about one.third its weight of water; .. E.
ffy-fve parts Of lime absorb seventeen
parts water, and is called by chemists n.y.
drate of lime and when hydrate Of lime
becomes carbonate of lime by long expo
sure to air, the water is expelled, and the
carbonic acid gas takes its place. Wher
lime. whether freshly burnt or slaked, i:
mixed with any moist, fibrous, vegetable
matter, and they form kind OF compos
together, of which part is usually soluble
in water. By this sort Of operation lime
renders matter which was before compar
atively inert, nutri,ive; and as charcoa
and oxygen abound in all vegetable mat
ters, it becomes at the same time conVer
ted into carbonate ofhme,
Mid lime, powdered limestone, marls o.
chaks. have no action Of this kind upol
vegetable matter; they prevent the too
rapid decomposition of substance already