The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1889-07-06
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

4 Dutch engineer, W. H. Ter Meulen, has
nut in operation novel plan for the recovery
from beneath a submarine sand-deposit OF gold
and silver amounting to several million dollars.
The war-ship Lutine, sunk in Dutch waters IN
1899. carried this treasure, of which about half
amilion dollars has been recovered at different
times. The new apparatus for penetrating the
sand covering the ship consists OF a very strong
hose seven inches in diameter, from the lower
end of which is suspended heavy cast iron
tube five feet long, with copper rose, through
which the water injected into the hose with
pressure up to 125 pounds to the square men.
radiates against the bed of sand. The bank IS
rapidly disintegrated so that well may be
made to the Lutine through 26 feet of sand in
nine minutes. The divers may then descend,
and work several hours the upward current
preventing the retilling of the well.
THE LARGEST METEoRIC IRON.
The heaviest purely metallic meteorlte known
is the ''thunderbolt' of the Arab Sheik kalaph
Ben Assab. 1t fell in Central Arabia, and is
one of the ten known meteontes that have
been seen when falling. 1t was bought by
English authorizes, who have since caused it to
be chemically analysed. 1t contains 9l.Q per
cent. of iron, 40 nickel, O;66 cobalt traces OF
COPPER phosphorus, and 0.39 of amorphous
carbon Its weight is 120 pounds. Much
larger stony meteOrites are known, including
one of 25 tons.
DARK LIGHTNING FLASHES.
1t often happens nowadays that the camera
A fresh instance of this is the curious phenome-
non of a dark flash of lightning, which has
been photographed among the ordinary white
flashes. The only plausible explanation OF this
appearances that of Prof. Stokes, +. X 3, and
Prof Curtis of Harvard College, who have in
dependentIv arrived at the conclusion that the
dark flash" is really the path of a vanished
fiash-that is, track of heavy nitrous oxide
gas left behind in the atmosphere, lmpervlous
to the flashes of light Immediately following,
and consequently appearing Opaque III the
picture.
A GEOLOGICAL LINK.
The Natural History Museum of Paris has
received specimens of the African Mud Fish
(ProtoDtel1ts dnnectens Or. } which have excited
the interest of naturalistS on account OF being
fishes with a dOuble-breathing apparatus and
double heart chambers, or Yeritable link be-
tween the fishes and the amphibla. This pecu-
liar animal lives in the rivers of Central Africa,
another species of the genus being found IN the
tributaries of the Amazon, and still another IN
the swamps of South Australia. The African
species is from 15 to 80 inches long, and Is most
abundant in flooded swamps, feeding on water
insects 1t propels its eel-like body through
the water by its tail, but as the swamp becomes
dry it ceases to breathe with its gills and makes
use of its lungs, becoming dry land animal.
Late discoveries show that the creature makes
the change by burrowing into the mud when
it becomes covered with a Shiny secretion,
which soon hardens into shell or cocoon.
Thus sealed it may remain in dry place four
or five months, to reappear on return OF water.
THE AMERICAN CEREAL.
OF maize or Indian corn in the United States,
Mr.. ]. III. Patton says: IA brief comparison
NAV give partial view of the immense value
of this crop, which next to rice supplies food
directly or indirectly to the largest number of
the human race. In 1880 the corn-crOp was l.
1874 S6I, 535 bushels. This was more than two
and half times the next greatest crOp-the
u hon
all our other crops of grain cOmbined-the
wheat, the rye, the barley, the oats, and the
buckwheat. 1t is quite probable that this ratio
of production, or nearly so, will continue"
THE CONGRESSES.
Affairs of human interest are likely to be
pretty thoroughly discussed at the information
al congresses to be held in connection with the
Paris Exhibition. \ few of these meetings
which will continue for periods ranging from
four to sixteen days, are the following: Open
ing in July-technical education, photography
of the exact sciences, chemistry, ballOoning, pig
cons; in August-hygiene, higher education,
physiological psychology, geography, photo
graphy criminal anthrOpOlOgy, primary edu-
cation, horticulture. prehistoric man and re-
mains, electricity; in Observation-Disclosures
try, mines and metallurgy, applied mechanics,
meteorOlogy, river utilization, commerce and
industry, NEUROLOGY and climatology.
MISCELLANEOUS.
A Mexican plant, called by natives the herb
of prophecy" is reported to induce a sleep
seemingly identical with the hypnotic state.
The patient is completely insensible. but an
swers questions put to him, and obeys any
commands given.
The London Geological Society has MEM
bership of 1906 At the close of last year its
animals numbered $780, of which 1121 had
been added during the year.
A process of removing tattoo marks, recon-
mended by VI. VariOt, consists i'll re-tattOOing
a small patch at time with tannin, then rub
bling with nitrate of silver crayon, and after
ward sprinklng with tannin powder several
TIME daily for several days. In a fortnight or
so dark crust comes away, leaving only an in
conspicuous reddish scar.
An official report states that in England and
Wales 546 persons were killed by lightning
during the % years from 1852 to 1880. The in
habitants of rural districts are found to suffer
more from lightning than those of towns, while
vicinity to the west and south coasts reduces
the chances ofinjury by lightning, and distance
from the coast and high land seems to increase
them.
In experiments continued for four wears, NJ.
f. Larroque has found that after eight or nine
months, copper wires under the action of cleo
trio currents show signs of deterioration.