The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1885-07-25
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

DRY ROT.
Russian experimenter has found that thorough
dryness maintained for twenty-four hours will
destroy the parasite producing dry rot in wood.
A concentrated solution Of common salt is very
eficacous, and still better is strong solution of
blue vitriol, but he considers the best, cheapest
and most convenient material to be the tar obtain
ed when birch wood is distilled for acetic acid.
SAFETY OF FIRE-PRooF PILLARS.
Prussian authorities regard cast-iron pillars as
very dangerous in case of fire, and have forbid
den their use in inhabited buildings, while allow
ing wrought-iron to be employed. This has led
Prof. Bauschinger, of Munich, to make a long
series of actual trials, which have shown him that
cast-iron is really much the reliable material
of the two. He loaded pillars Of these substances
with the weights they usually expected to bear
in buildings, and heated them successfully to
various temperatures up to rcd heat, letting
stream of cold water play on them, exactly as
would be the case in fire being extinguished by
fre-engines. The cast-iron pillars were much
cracked and damaged by this treatment, but con-
tnued to sustain their loads safely, while those of
wrought-iron were much bent before redness was
reached, and so twisted when cold water struck
them that they could not carry their loads. In
experiments with other materials concrete resisted
fire of three hours duration, ordinary brick stood
very well, but less resistance shown by granite,
sandstone and other natural stones.
ELECTRICITY IN METALLURGY.
The remarkable effect of electric discharges in
causing dust and smoke in the air to settle was
some time ago pointed out by Prof. Lodge. This
led to Investigations by an English lead smelter,
Alfred o. Walker, which have resulted in the i'm
portant discovery that constant discharge of
electricity in the fues of lead works causes the
lead fume to condense and settle very rapidly.
Much time is thus saved, while the loss of lead
fume is greatly reduced. The discovery applies
to other volatilizable metals besides lead.
SELF FED ELECTRIC LAMPS.
In recent electric lighting experiments it has
been attempted to give each lamp its own battery.
Perfect success is reported, and portability has
been gained by the use of battery of great power
and small size. The elements are small packet
of chloride of silver and two plates of zinc which
are placed in the cell with weak solution of
caustic potash, forming what is known as the
Skrivanoff primary battery. After time the
chloride of silver is reduced to metallic silver,
when it is easily restored by washing in mixture
of nitric and hydrochloric acids. With each re-
newal, small battery viii feed glow-lamp
twelve hours.
MISCELLANEOUS.
Correcting Interpretations, Mr.. Pryor, the
traveller who recently visited the bird caves of
North Borneo, states that the edible bird's-nests
so highly priced by the Chinese are made from
algae worked up in the birds mouth with saliva.
They cannot be formed from saliva alone. The
nests are of two colors, the black nests being
simply white ones grown old and frequently re-
paired.
A remarkable illustration of naturalization
of ground is found by Mons. Alluard in the fertile
French valley of Limagne. From the chain Of
the Domes the wind brings vast quantities of vol
canic dust--rich in phosphoric acid, potash and
lime-the annual deposit in the valley being esti-
mated at about three fourths of pound per square
yard.
An observatory for public use has been opened
in Christiania. 1t is provided with great re-
fractor-said to be the fifth in size in the world
together with numerous charts and diagrams Of
the heavens.
gigantic stone spear-head has been unearthed
in northern Italy. 1t is too large to have been
used in war, and archaeologists conjecture that
the primitive people of the stone age employed
it as religious emblem.
A sample of preserved tomato examined by
French chemist seemed to be chiefly composed of
carrots and pumpkins cOlored with some aniline
dye.
Since 1885, it is stated, 1909 persons have been
struck dead by lightning in France, 1000 have
received fatal injuries, 1000 have been seized
with momentary and temporary paralysis, and TO-
900 have been struck without receiving any in
jury.
Scorpions, spiders and various insects have
been observed to remain motionless if any person
blows strongly upon them in vertical direction.
An English geologist, T. A. Jameson, finds
evidence that the Mediterranean was at one time
shut off from the Atlantic; that it was divided
into two distinct basins by strip of land extend
ing from Italy to Africa; and that most of its
islands, notably Sicily and Malta, were connected
with the mainland.
tn communication " the London Royal So
ciety, shelford Bidwell has shown that iron bars
are elongated by magnetization; that steel bars
are elongated, but not to the same extent, soft
steel being elongated more than hard steel; and
that nickel is shortened.
The favorite cosmetic of the japanese, accord
ing to report by F. Sakaye, consists chiefly OF
carbonate of lead and rice-powder starch, which
compound has been used by women--apparently
without poisonous efects-since early in the eighth
century.
A French scientific authority states that hens,
ducks and geese having dark plumage lay earlier
and more frequently than those OF a light color
this difference only holding good, however, when
the birds live in the open air and are freely ex-
posed to the sun. sa ate.s
The fora of Ceylon includes 200 Towering
plants and $50 ferns, 100 genera of the Towering
plants not being found in the peninsula of India.