The Kanzas news., 1857-10-24
How Drouth Benefits the Soil.

That a season of extreme drOuth-so oft-
en- occurring and so I'M furious to our sum-
mer crops-should still prove beneficial to
the soil seems strange, but chemical science
shows us that drouths are one of the mate
rial causes to restore the constituents of
crops and renovate cultivated soils.
Mineral matter is taken from the soil by
the crown upon it, and also carried away by
the surface water flowing into streams, and
thence carried to the sea. These two causes,
always in operation, unless counterbalanced
bv other influences, would In time render
the earth barren waste. The diminutiOn
which arises from the first cause is In part
restored by manures, but not in all cases,
and Providence has provided way of its
own to supply lost mineral constituents
needed in the growth of plants. At inter
walls drouths occur to bring up from the
deep parts of the earth food for the use of
plants when the rains shall again fall.
The manner in which droutbs exercise
their beneficial influence is as follows: Du-
ring 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 sur
face creates vacuum (as far as the water Is
concerned) which is at once filed by water
rising up from the subsoil the water from
the subsoil is replaced from the next below,
and in this manner the circulation of water
in the earth is the reverse of that which
takes place in wet weather. This progress
to the surface of the water in the earth man
ifests itself strikingly in the drying up OF
springs and wells, and streams which are
supported by springs.
1t is not, however, only the water which
/ is brought to the surface of the earth, bui
also all the water holds In solution. These
substances are salts of lime and magnesia
/ of potash and soda, and indeed whatever
the subsoil or top strata of the earth may
contain. The water, on reaching the sur
| face, is eyaporated, and leaves behind in th'
soil its mineral salts, the chief of which are
lime, magnesia, phosphate of lime, sulphat,
of lime, carbonate and silicate of potash ane
soda, and, also, common salt-all indispen
sable to the growth of the vegetable pro
ducts of the farm. Pure rain water, as /
falls, viii dissolve but very small portion
of some of these substances, but when I
sinks into the earth it then becomes stron9l.
imbued with carbonic acid from the decOm
position of vegetable matter IN the soil, ant
thus acquies the property of readily dis
solving minerals, on which it before coul'
have very little influence.
Several experiments tried by Professo
Higgins go to show this action of drouth il
bringing matters to the surface of the soil
In one case he placed a solution of chlorld
of basium In the bottom of a glass cylinder
and then filed it with dry soil. After lone
Iexposure to the rays of the sun, the surfac
, of the soil was tested with sulphurie acid
and gave eopious preeipitate of sulphat
of baryta. Chloride of lime, sulphate G
soda and carbonate of potash wese experl
, mented upon in like manner and, upon tn
; application of proper tests, the surface G
the soil showed their presence in large quan
titles, drawn up by the rising of water iron
! underneath, as in the ease OF drouth.
5 The parched earth-every green thin
: dwarfed in growth or withered by long con
tinued heat-seems suffering under an al
fiictiye dispensation of Providence, yet v
e should not murmur; it is blessing in DIS
S guise. The early and the latter rain ma
iproduoe at once abundant crops. but DIR