St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1894-03-31
tARMERAND PLANTER.
LIME IN AGRICULTURE.

Proper Conditions.
1t may be said, that the difference
between lime and gas lime is that the
latter is common lime that has made
various combinations with the impure
ties it has absorbed from the gas Of
which 1T has acted as q filter. The
most important of these impurities is
suiphuric acid, and SO far as this has
combined with the lime. it has changed
the lime into sulphate, simply gypsum
or plaster. But there is large guam
tlty OF other impurities in the crude
gas which are taken up and removed
BY the lime. The lime is used in the
form of an intimate mixture with
water milk of limc) and the gas is
passed through this semi-liquid. being
thus freed from every impure
ty that combine with the lime.
These impurities are carbolic acid,
sulPhuric acid, sulphureted hydrogen
and sulphurous acid. Thus the waste
lime, when it has been exhausted. be-
comes to the largest extent carbonate
and sulphate of lime, with consider
able proportion of sulphureted hydro
gen held in the moisture of the gas
lime. 1t is this uncombined gas to
which the intolerable odor of the fresh
gas lime is due, but this escapes by
evaporation in short exposure to the
atmosphere. So that gas. lime is
valuable first for the sulphate Of lirle
1t may contain, next for the carbonate
OF lime it has in it (this is not SO much
as there is of the sulphate), next for
whatever little uncomb ined lime may
remain, and this is so small quantity
as not to be worthy of notice.
Then the other substances it cen
tains-the sulphurous acid and the
snlphnrefed hydrogen-are positively
injurious, and the lime :Il@u -
its fresh state to the land will
kill all vegetationby the caustic effects
of these two acid substances. So that
the gas lime is quite difficult to be
given away, and for any use the farm
er can put it to. the best is to make
roads of it. and there will be no weeds
on them to annoy him afterwards for a
long time. If mixed with coarse gra rel
this kind Of lime will make really good.
hard. scrviceable roads and foot paths
on farm. But if it is to he used as a
fertilizer, for the useful parts Of it, it
must be kept exposed to the air for at
least a year. Or it may be used on
weedy fallow with good effects if she
land lies year or more.
As good lime may be procured very
cheaply, and more of it may be hauled
~ = ln0A - ~ y
lime, this is hardly worth accepting rs
a gift, even were it delivered free on a
farm. But the term air-slaked lime
needs some explanation. When lime is
exposed to the air it first absorbs moist
ure to the extent of about ne-third
of its weight, and falls to q very
fine powder. This fine division exposes
almost an infinitely extensive surface
Of it to tho air, and the greedinesseof
the lime for carbonic acid. which exists
abundantly in the air, causes it to re-
turn quickly to its previous condition
of carbonic, as It was in the limestone.
This greatly reduces its value as asfer-
tilizer, because it takes from it its
caustic qualities, upon which the larger
part of its value, that Of an active de-
composing agent. rests. Thus the value
of the lime depends considerably upon
the length of time it has been in air
or exposed to the air after it.
On the coast lands of Virginia and
Maryland q large quantity of lime in
the air-slacked condition is brought
fre8 0i&aElSnia, and much of this
has lost half its ORIGINAL value. Int for
the. 1fe ills on which it is used it
Henry Stewart, in Country Gentleman.