The Plymouth Democrat. (Plymouth, Ind.) 1869-1941, 1870-05-19

IF q wick be put into o lamp containing
oil, the oil, by Capillary attraction gradual
,ypermeates its whole length, that which is
above as well as that below the surface of
the liquid When the lamp Is st burn
ing, tue oil at the flame is consumed, and
as each particle disappears, its place is
suppi'ed by new one, until the lamp is
eml ty or The fame is extingushcd.
Something quite analogous occurs in
the soil, by which the plant is fed. The
soil is at once lamp anu wick, and the
water Of the soil represents the oil Let
evaporation Of water from the surface o.
the soil or Of the plant take the place of
tne combustion OF oil from a wick, and
the matter stands THIS: "Let Us suppose
dew or rain to have satu ated the ground
with moisture for some depth. On recur-
renee of dry atmosphere with sunshine
and wind, the surface Of the soil rapidly
dries; but as each particle of water dries
! (by evaporatiOn) into the atmosphere, its
| place is supplied Thy capiiarity) from the
/ stores below. The ascending water brings
along with it the soluble matter of the
! soil, and thus the roots OF plants are stu
aied In stream of their appropriate food
The movement proceeds i'll this way SO
long as the surface is drier than the deep
er soil. When, by rain or otherwise, the
surface is saturated, it is like letting thin
stream Of oil run upon the apex of u
lamp wick no more evaporation into the
air can occur, and consequently there is
n0 longer any ascent OF water; on tae
contrary, the water, by its own weight,
penctrates the soil, and if the underlying
ground be not saturated it'll moisture, as
can happen where the subterranean foun-
tains yield meagre supply, then capillar-
ity will aid gravity in its downward dis.
! tribution.
1t is certain that portion of the mine
raj matters, and perhaps also some or
! ganc bodies which feed the plant, are
more or less freely dissoly ed in the water
or the soil So long as evaporation goes
on from the surface, SO long there is a con-
/ slant upward flow OF these matters Those
portions which do not enter vegetation
accumulate On or near the surface of the
ground when n rain falls, they are washed
down again TO a certain depth, and thus
are kept constantly changing their place
with the water, which is the vehicle of
Their distribution. In regions where rain
/ falls periodically or not al all, this upward
/ flow OF the soil water often causes an ac-
emulation of salts on the surface of the
ground. Thus in Bengal many SO Is
which in the wet season produce the
most luxuriant crops, during the rainless
portions ef the year become covered with
white cruss of saltpeier. The beds of
nitrate of soda that are found in Peru,
and the carbonate of soda and other salts
which incrust the deserts of Utah, and
often fill the air with alkaline dust, have
accumulated in the same manner. SO in
our western caves, the earth sheltered
from rains is saturated with salt-epsom
salts, Glaubers salts and saltpeter, or
mixtures of these. Often the rich soils
of gardens is slightly incrusted in this
manner in our summer weather; but the
saline matters are carried into the soil
with the next rain.
Tt is easy to see how, in a good soil,
capillarity thus acts in keeping the roots
of plants constantly Immersed In stream
OF water or moisture that is now ascend
ing, now descending, bnt never at rest
and how the food of the plant is thus
made To circulate around the organs fitted
for absorbing II.
The same causas that maintain this per-
peiual supply Of water and food to the
plant are also efficacious in constantly pre-.
pairing new supplies of food; As before
explained, the materials OF the soil arc al