Edgefield advertiser. [volume] (Edgefield, S.C.) 1836-current, 1855-07-25
From the Baltimore Sum-
BENEFITS OF DROUGHTS.
LABORATORY OF STATE CHEMEsr, !

LABORATORY OF STATE CHEMIST, !
No. 20 Exchange Building.
1t may be consolation to those who have
felt the influence of the latg long and pro.
tracted dry weather to know that droughts
are one OF the natural causes to restore the
constituents of crops and renovate cultivated
soils. The diminution of the mineral matter
of cultivated soils takes place from two
causes.
lst, The quantity of mineral matter car.
ried off in crops and not returned to the soil
in manure.
I'd. The mineral matter carried off by
rain water to the sea by means of fresh wa.
ter streams.
These two causes, always in operation,
and counteracted by nothing, would in time
render the earth barren waste, in which no
verdure would quicken and no solitary plant
take root. A rational system of agriculture
would oblvate the first cause of sterility, by
always restoring to the soil an equivalent for
that which is taken off by the crops; but as
this is not done in all cases, Providence has
provideda a way of its own to counteract the
thritessness of man, by instituting droughts
at proper periods to bring up from the deep
parts of the earth food on which plants might
feed when rains should again fall. The man.
ner in which droughts exercise their benef.
cial influences is as follows. During dry
weather continual evaporation Of water
takes place from the surface of the earth,
which is not supplied by any from the clouds.
The evaporation from the surface creates
vacuum, $50 far as the water is concerned)
which is at once filled by the water rising up
from the subsoil of the land the water from
the sub-soil is replaced from the next below,
and in this manner the circulation of water
in the earth is the reverse to that which
takes place in wet weather. This progress
to the surface of the water in the earth mani.
tests itself strikingly in the drying up Of
springs, and of rivers and streams which are
supported by springs. 1t is not, however,
only the water which is brought to the surface
of the earth, but also all that which the wa.
ter holds in solution. These substances are
salts of lime, and magnesia of potash and
soda, and indeed whatever the subsoil or deep
strata Of the earth may contain. The water
on reaching the surface of the soil is evapo-
rated and leaves behind the mineral salts,
which will here enumerate, viz: Lime, as
air slaked lime magnesia, as air-slaked
magnesia; phosphate Of lime, or bone earth:
sulphate of lime, or plaster Of Paris carbon
ate of potash and soda, with silicate of pot.
ash and soda, and also chloride of sodium
or common salt. All indispensable to the
growth and production Of plants which are
used for food. Pure rain water as It falls
would dissolve but rery small proportion
of some Of these substances, but when it be.
comes soaked into the earth it there becomes
strongly imbued with carbonic acid from the
decomposition of vegetable matter in the soil
aud thus acquires the property of readily
minerals on which it before could
have very little influence.
was first led to the consideration Of the
above subjects by finding, on the re.exami.
nation of soil which nalysed three or
four years ago, larger quantity Of a partic.
ular mineral substance than at first found,
as none had been applied in the meantime.
The thing was difficult of explanation until
remembered the late long and protracted
drought. l then also remembered that in
Zacatecas and several other provinces in
South America, soda was obtained from the
bottom of ponds, which were dried in the
dry. and again filled up in the rainy season.
AS the above explanation depended on the
principles Of natural philosophy, | at once
instituted several experiments to prove its
truth.
Into glass cylinder was placed a small
quantity of chloride of barium, in solution !;
this was then filled with dry soil, and for
long time exposed to the direct rays of the
sun on the surface. The soil on the surface
of the cylinder was now treated with sui.
rhuric acid, and gave copious precipitate
of sulphate of baryta.
The experiment was varied by substituting
chloride of lime, sulphate of soda, and car
Donate of potash, for the chloride of barium,
and on the proper reagents being applied IN
every instance, the presence of those SUBJ
stances were detected in large quantities on
the surface Of the soil in the cylinder. Here
then was proof positive and direct, by plain
experiments in chemistry and natural philoso.
ply, Of the agency, the ultimate, beneficial
agency, of droughts.
We see, therefore, in this that even those
things which we look upon as evils, BY Prov.
idence, are blessings in disguise, and that
we should not murmur even when dry sea.
sons afflict US, for they too ale for our good.
The early and the later rain may produce at
once abundant crops, but dry weather is also
a beneficial dispensation of Providence, in
bringing to the surface food for future crops,
which otherwise would be for ever useless.
Seasonable weather is good for the present,
but droughts renew the storehouses of plants
in the soil, and furnish an abundant supply
Of nutriment for future crops.
JAMES HIGG1Ns,
State Agricultural Chemist.