St. Landry democrat. (Opelousas, La.) 1878-1894, 1881-10-22
SCIENTIFIC MISCELLANY.

vast masses pfOUdUly cAlSC Ill tHo Ill
accessible interior Of the globe. 1t is
computed that the world is five times
as heavy as an equal volume of water,
while the rocks Of the earth's surface
only average two and e.half times
the weight of water. 1t follows from
this that the still molten centre must
contain great amount of very heavy
substances. With water as a unit, the
specific gravity, or comparative weight,
of gold is about 10, platinum 81, and
iridium 90, silver being but 10, and
iron s. When the globe was in liquid
state, these metals would have had a
tendency to gravitate toward the centre,
and those Of extreme density now found
by us owe their appearance near the
surface to volcanic agencies. The great
bulk must yet remain near the centre.
According to the recent estimate OF
Sir w. Armstrong, the heat OF the sun
falling upon one acre OF the eartl's
surface in the tropics, would be capable,
If fully utilized, Of developing a power
of 1000 horses for nearly nine hours
every day. The most promising means
of adapting his vast energy to mans
purposes seems to be the conversion
of the heat into electricity, and the
production of economical apparatus for
effecting this result is now eagerly
awaited.
Sir w. Thompson has recently cal
culated that the energy Of Niagara Falls
might be converted into electricity and
carried over half-inch copper wire
to Montreal, Boston, New York or Phil
adelphia, with loss of only twenty
per cent of power, and at a cost which
would render this an economical source
Of energy. He believes that the last
great difficulty in the way Of making
electric force available economically at
a distance has been overcome by the
invention of Faure's storage or accu-
mulating battery. By its aid the cleo
trio current may be stored as received
and used as desired, in subdivided
form, for the production of the electric
light or as motive power.
Whether or not fishes have inter-
walls Of sleep, like the land animals with
which we are familiar, has but just
been decided. The curious behavior of
a dozen carp in the Berlin aquarium
attracted attention, and Investigation
showed that the fish when in certain
positions in which they would remain
for hours were in reality asleep. Some
OF them selpt SO soundly that only re-
peated blows or shaking would awaken
them.
The flesh of a pike recently caught
in the North Sea has been found to be
full of trichina. The parasites are sup
posed to have been introduced into the
fish's body in offal eaten by it.
Longitude on the earth's surface is
now computed from various meridians
by different countries. At the recent
meeting ofathe Geographical Congress
in Vienna, Prof. Barnard, of Columbia
College, proposed new system for
universal use, the plan being to divide
the globe into "a meridians of Is degrees
each, corresponding to the "a hours Of
the day, the first meridian to pass
through Behring Strait.
Ne
Biologists estimate the coal beds of
Great Britain to have an area Of about
$4,000 square miles; of Spain, 1900; of
France, 1900; and of Belgium. 518.
The coal-bearing area Of the United
States is nearly 100000 square miles,
with perhaps 10000 square miles of
workable beds of coal.
The effects Of sea- water upon land
have thus been determined at German
station of experimental agriculture:
Land that has been submerged by
sea-water generally proves sterile for
some time, in some cases for ten to
fifteen years. This can be traced to the
cooperation of the three following
chemical cases, in addition to the me-
chanical injuries produced by the inun-
dalton: To the introduction OF too great
proportion of chlorine salts; to the
microscopic property communicated to
it, preventing it from drying properly !;
thirdly, from the formation Of green
vitriol or sulphate Of iron, which is
known to exert a very prejudicial effect
upon plant growth. Land which has
thus been damaged should be drained
as quickly as possible, sown with grass
and clover, and allowed to rest. Ex-
nl, 4lnk ikn Eor.