The National tribune., 1881-12-17
feet will be the reduction of the mass to pow
der-COuntrq Gentleman.


| der.-Country Gentleman.
ACTION OF FROST ON LAND.-A clOd of earth
will retain certain portion of water,-this during
frost will become ice; in doing so it expands
and of course must separate the particles OF soil
further from each other than naturally; when
frozen, the clod still retains its shape on account
of the s0lidity ef the ice, but Immediately thaw
takes place the water resumes its original bulk,
which then no longer supports the earthly parti-
cles, and they must as consequence become, as
it were independent of each other, and fall apart,
and having been so loosened are perfectly friabe,
falling to powder by the least touch. The great
utility of this crumbling OF the soil In an agri-
cultural point of view is obvious. BY this means
much larger amount Of surface of earth is ex-
posed to the action of the air than otherwise
would be- The roots of plants growing in such
land are enabled to penetrate as it were, into a
new soil. Some of the hardest rocks contain the
most valuable ingredients as food for plants;
much Of the cultivated land has been originally
produced by the surface of the rock which is
now below the verdant field having been crushed
through the intermediate action of frost.
GROWTH OF PLANTS BY ELECTRIC LIGHT
For some time past DR.. Siemens, Of England, has
been making experiments with electric light IN
the growth of plants. It has been clearly estab-
1ished that etioated and blanched plants which
have purposely been grown in the dark until no
green color pervaded the leaves, have elaborated
chlorophyll and assumed a green color, under
the influence of electric light, SO that, as mat
ter of fact the electric light to have essen
TALLY the same power on plant growth as the
rays Of the sun. The application of this light
has SO far been only of an experimental charac
ter It was found that, in glass house, plants
that came in direct contact with the streams of
light were injured, but sheet of glass, placed so
that the light must pass through it, counteracts
these evil effects. Another difficulty appears to
be the proper diffusion of the electric rays, and
their equal concentration over given area, in
order that the light may act upon plants as the
Suns rays would do on a bright day Whether
this effect will be best obtained from large cen
ters or from a number of smaller ones remains to
be seen; but.of the ultimate success and mastery
Of these details there can hardly be doubt, con-
sidering what has already been accomplished by
science in the same direction. It may revolu-
and flowers cut of their natural season, for al
though it is matter of general belief that plants
must rest at light, and that it is matter Of fact
shat plants become etiolated if forced to grow in
the absence Of light yet it may not necessarily
follow that they may not grow On uninterrupt-
edly if sufficient light be present. We see some
thing analogous to this in the rapid growth of
plants in necthern latitudes where daylight, for
q brief season, is almost continuous
From an economic point of view but little can
yet be judged as to the value Of the experiment.
Dr. Siemens it is stated, uses the waste steam
from his driving engine to heat range of green
houses and forcing houses. The engine boiler
thus supplies both light and heat, undoubtedly
a great boon to gardeners and florists. In addi-
ton to this the electric force is used to pump
water, drive straw cutting machines, and per-
fosm variety of services Of similar kind