The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1902-11-08
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

Veet-POcket Fresh AHA Need 10 FIJI
Electric Fire Extinguishing-Su
in a Vertical Pit-Color of Water-The
New Experimental Psychology-The
Coming Plant Food-Picture Telegra-
REPRESENTATION by Pressure--A Bo-
tanical Marvel.
The so-called "aerogen stone' Of NJ. Georges
Joubert is stated to contain specially COM
pressed peroxide of calcium or potassium. with
permanganate, hyperchlorite, and some salt
of copper or nickel. When placed In water, 1t
is decomposed without heat, giving off chemic-
ally pure oxygen. This discovery supplies us
with oxygen tablets, of which pound will
yield 20 to 30 gallons of oxygen, and which can
be used in a submarine boat or other close space
as needed to keep the free oxygen in the at
mosphere at its normal proportion of Fl per
cent.
OF the many wants now felt in the arts, few
are more important than that of a satisfactory
paint for iron and other metals. Thousands of
tons of paint are used annually on bridges and
other structures. but it is pointed out that no
compound tried gives perfect protection. The
perfect paint must be tenacious, pliable, ad-
hesive, inert, and proof against moisture, oxy-
gen, and the fumes from burning coal
~
The novel fire pump of Robert Lefebre, of
Rouen, carries an electric motor, which is con-
nected to a supply of energy by throwing
hooked pole over street-car or electric. light
wire. The apparatus is so small that it can be
drawn by one horse on two-wheeled cart, and
in a test made jet was being forced to height
of more than 100 feet within three minutes. To
get an equal stream steam pump required
fourteen minutes.
-
A curious phenomenon has been noticed in
the tropics that can never be seen at higher
ATTITUDES. A mining shaft at Sombrerete,
Mexico, is almost exactly on the Tropic of Can
Ger, and at noon on June 2lst the sun shines to
the bottom, lighting up the well for vertical
depth of LOO feet or more.
-.
The usual color of water-greenish yellow to
reddish brown-is now known to be due to dis
solved substances from decaying vegetation,
but particles in suspenson-usually mineral
and often containing iron-may be cause of
the color. The depth of tint is estimated by
comparison with a mixture of platinum and
cobalt, states DR.. A. E. Bostwick, the unit being
the color given to one million parts of water by
one part of platinum. AS rule, water near
units of color; near steep wooded or cultivated
slopes, 20 to 30 units; near similar but gentler
slopes, to 100; and in swamps, 100 to 500, or
even more. In the United States, northern
waters are more highly colored than southern.
Filtering does not remove the color, and, as
brownish water-though rarely harmful-is OBJ
jected to for drinking. the coloring matter is
often removed by chemical MEANS as by coagu-
lok; .v;+k ,bofo IF oil
a.
During the last few years much ingenuity has
been expended upon apparatus for studying the
operations of the human body The time of
these operations is measured by chromoscope
invented by Prof J.w .Fitz, of Harvard and he
has also devised location reaction apparatus
for recording quickness in touching suddenly
disclosed object, the effect of baseball and ten
mis- training being thus made evident. The al
gometer of Prof. Cattell measures the intensity
of pressure causing pain. Prof. Mosso's ergo
graph records the phenomena of work and fa-
tigue and his plethysmograph shows the vary
ing volume of the arm under different condi-
tions. Many forms of apparatus have been pro-
duced by DIR. E. w. Scripture, of Yale. These
record the time lost by runner after being sig-
nailed; the reactions in fencing the least
cold spots; the interval between steps and
time of feet on the floor and other interesting
phenomena.
An old dream of the chemist is the artificial
conversion into plant food of nitrogen from the
air. In the latest development of the Bradley
process, on which the inventor has been at
work several years, special electrical machine
fl,o nj
trous gases teus formed from atmospheric nitro
gen and oxygen being collected in water or di-
rectly combined with potash or soda.
-
The new picture transmitting apparatus of A.
Korn depends upon peculiarities of vacuum
discharges At certain degree of exhaustion
these discharges are very sensitive to slight
changes of circuit resistance, and the rays
emitted have extraordinary photo-chemical
activity. The picture to be sent is divided into
squares, each being projected in turn upon Sc
lenium cell. In the receiver a sensitive plate is
moved past an aperture transmitting the x-rays
at a rate corresponding to that of the original
picture at the sending end. and the current va
riations due to the lights and shadows falling
upon the selenium move galyanometer, which
in turn changes the length of the spark-gap
nation of the squares exposed reproduces the
picture on the plate. Pictures of 400 squares
have been successfully sent, the impression of
each square being given in two seconds, and it
is expected that exposure will be shortened to a
tenth of second.
No pressure yet reached destroys all bacteria
Milk has been subjected recently to pressures
up to 100000 pound per square inch, but it was
not completely sterilized, although brief COM
preston under 70 to 100 tons to the inch delayed
souring "a to so hours, and pressure of 80 tons
per inch for an hour caused the milk to keep
from four to six days. AS odd tastes and odors
were soon acquired, it seems that some kinds of
bacteria were killed while others survived the
tremendous squeezing.
-
Seeds of a tropical grass lately shown to the
London Linnean Society are pear-shaped bodies
five inches long and three inches in diameter
The enormous store of nutriment contained is
probably needed to give the plant successful
start amid the dense under growth of the jungle.
-.
Beri-beri an oriental disease very fatal among
coolies, has been much of mystery. Poor food
has been suspected as the cause, and now DIR.
Rost I. NJ. s., believes he has found the specific
organism in a bacillus of fermenting rice and
rice-liquor.
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