The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1905-09-23

Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
Radium Infection-varnish Of old violins
AN Automobile Trap Bleached Bread
"A Record Rainfall--Trade In Human
Elesh-Danger In Combs.
Laboratories where experiments in physics
are made must now be guarded against curious
disorder-that Of infection by radium. Several
electroscopes lately made in the physics build
ing Of McGill University were discharged by
natural leakage from 60 to 100 times as rapidly
as similar instruments used in the same build
ing two years before, and this extraordinary
leakage continued when the electroscopes were
removed to another building. Th5cause proved
TO be radio activity Of the raw materials. Other
electroscopes were made in the chemistry build
ing from other materials. and discharged at the
usual slow rate, and with these it was shown
that the emanatlon from radium had infected
every part Of the physics building. even drawers
and closets, and had impaired activity to sheets
OF mica lead foil, iron. zinc. tin and other sub
stances. It is calculated that If the emanation
were now to be stopped by removal of the ra-
dunn. the building would continue to increase
in radio-activity for two or three years, the in
lection falling only half at the end of forty
years. Infection can be avoided by keeping
radium in sealed vessels, and can be mostly re-
moved by acid.
varnish is found to have decided influence on
the tone of violins, and 1t would be gratifying
to know just what the composition is that covers
q stradivarius. In his new work, George Fry,
r. @. g., deals with the italian violin-varnishes
back to the sixteenth century. He concludes
that turpentine, Iinseed oil and nitrated rosin
are more likely to have been the materials than
any remarkable mystic gum, and by expert
ments with nitrated mixtures Of rosin and lin
seed oil he has given strength to bis theory.
81
The duration Of whooping cough is lessened by
German doctor from IS to IS daysby the use Of
solution Of fiuoroform in water.
The novel detective apparatus of Major Lang,
and English constable. includes an electric sig
mailing mechanism and anon-magnetic chronom-
eter. which are enclosed in small box provided
with holes for attaching two signal wires. 1t Is
designed for catching automobiles who are ex-
ceeding the legal speed. Its use requires three
policemen, who are stationed along the street at
measured intervals of a furlong. AS motor
car Is approaching A presses button, signaling
b, who holds the box and connects A with the
watch. A again presses the button as the car
passes his hiding place, thus starting the watch,
which runs until stopped by B as the vehicle
reaches the end of the first furlong. hasty
calculation Is made, and II it shows excessive
speed. presses button. calling G, who rushes
into the street in time to stop the law-breaking
chauffeur. The device seems to have proven
efficient, and on its evidence $3.50 was paid in
fines on a recent week.
The demand in Paris for very white bread has
led to experiments in ozone bleaching. The
nour was treated electrically, ozone being gem
Grated in the process, and bread of unusual
whiteness was produced, but the changes in the
-four made the fatty substances rancid and part
ly oxidized them into acid substances. greatly
impairing the taste and nutritive value of the
bread.
Phosphorescence is still much of mystery.
The glow of phosphorus at ordinary temper
atures has been variously explained, being
thought by some to be an electrical phenome-
non, but French investigator has now shown
that it is mainly or entirely due to the slow COM
bustion of an oxide that forms on the outside
and is more volatile than the phosphorus itself.
IS
In plant forcing by electric light foreign
grower has found that red globes produce greater
intensity of color and yellow globes more deli
cate color.
The arrival in London of specimen of the
bird-eating spider calls renewed attention to
little known insect that is more powerful than
the famous Tarantula. It is the largest spider
known, and in its tropical South American home
f1uf,I FOR
ming-birds and inches instead of flies. When
the enormously strong threads are spun across
little-frequented roads they often strike the
faces of travellers with great violence. The body
OF the spider is often three inches long and as
large as hens egg. and its horrible aspect is in
creased by the long hairy legs.
A@s
The heaviest rainfall of short duration ever
recorded accurately Is said to have been the re-
cent one at Santiago de Cuba. An English en-
gineer found the rate to be more than four
inches an hour. and between seven and ten
o'clock in the evening total fall of more than
foot was registered by the gauge. The storm
covered nearly 800 square miles, in places being
even heavier than at the point where the meas
urement was made.
Among the new industries that have been de-
veloped by the exigencies of modern life. none
!, is more surprising than thato supplying human
skin. Experiments in grating to cover extern
siye injuries have been SO successful that there
is considerable demand for live skin, and the
London hospitals have long lists of men and
women-not all of the very poor class-who are
ready to sell their flesh when 1t is wanted.
"a
The spontaneous ignition of ladies' celluloid
combs has attracted much attention in Germa
ny. DR.. w. Normann has initiated the condi-
tions under which such combs are exposed to
heat when worn, and finds that the temperature
of the celluloid may rise to 212o f., which is dam
Rerously near the decomposition point of this
material. Insulated by a bad conductor of heat,
like hair or WOOL there is great risk that cellu-
loid viii ignite when exposed to the radiation
from a stove or lamp.