The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1902-07-26

a
Eliza Cook.
Correspondence Baltimore County Union.
SCIENTIFIC MIS- CELLANY.
Radiography Without Apparatus-Ocean
SOundinQS by BallOOn-Our Course in
Space-Color-B lindness-Cement Sleep
ers-Carbureted Acetylene-Bacteria
and Nutrition-Fuel After Coal-Calling
Mosquitoes.
Radium, the most active of the three new ele-
ments emitting invisible radations, has been
proven by Prof. George F. Parker to be a cheap
and efficient substitute for X-ray apparatus for
photographing internal parts of the body. When
the hand was placed between the metal and the
sensitive plate, a picture showing the bones was
SaAcn III nuIL q nIuute. ASIDE from JnlS Valua-
BILE property, radium rays act like Roentgen rays
in producing phosphorescence and discharging
electrified bodies Radium is one Of the greatest
of puzzles on account of its anomalous expendi-
ture of energy without appearing to lose any or
to receive any from the sunlight or other source
~
The somewhat novel use of balloons for hydro
graphic surveys has been tried at the suggestion
of two French engineers 1t is well known that
shadows and rocks in water can be seen from an
elevated point directly above them, and the
aeronaut saves much time by picking out the
shoals on dangerous coasts. These spots are
then further studied by the usual soundings.
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The sun, drawing its attendant planets, is
journeying through space at the rate of to IL
miles second. Its path is often supposed to be
orbital and to extend around the cluster of stars
known as the Pleiades in period of millions of
che d,-s,
their approach or recession with the spectre
scope, Prof. W. w. Campbell has placed the point
toward which we are now heading in the con-
stellation Hercules, nearly 19o south of Alpha
Lyra or Vega.
The "sun pillar that lately attracted wide
spread attention in England was an orange per-
pendicular shaft of light reaching 30 to 100 above
the horizon. One explanation is reflection from
tiny ice crystals.
The color blind, those in whom the perception
of light is normal but with defect in the dis
tinction of color, are divided by Mr.. F. w. Ed
ridge Green into classes based on theory of
color evolution. A patient almost totally color
blind in one eye has given an unusual opportu-
nifty for study, and the spectroscope has proven
that he can just perceive the red and the violet
being diluted with the gray that takes the place
of all intermediate colors This is what should
be expected, the colors of greatest and least
wave-length being first separated. Other cases
demonstrate further that in successive degrees
of color-blindness the green-at the middle of
the spectrum-appears next, then yellow, then
blue, and finally orange, completing the series.
The eolor-blind, therefore. are classified in ac-
cordance with the number of primary colors
recognized. If the normal-sghted be called
hexachromic, and others are tetrachromic, tri-
chronic and dichromic, the totally color blind
being monochrome.
-
Wood sleepers for railways have the disadvan-
tage of short life under the most favorable con-
ditions, and in warm climates they are quickly
destroyed by insects and vegetable parasites.
Creosoting, while adding somewhat to the dura-
bility, gives increased risk from fire. Iron stone
marble and tempered glass have been tried, but
all have proven more or less unsuitable for
sleepers. The merits of armored cement which
has proven very effective in beams and Orders,
are urged by M. Michael Sarda. Sleepers of this
material would cost little more than those of
iron and three times as much as those of wood,
but they would be indestructible, while givinga
more stable roadway, and it is claimed that in 50
years they would yield large saving.
IS
Acetylene gas is readily carbureted by DIR. N.
Caro-, of Berlin, by passing it through petrol.
About l25 grams of petrol taken up by 100 liters
acetylene yields 150liters of carbureted gas with
about 30 per cent. greater heating power than
ordinary acetylene. Great power with little
weight is expected if it can be used in explosion
motors.
The effect of intestinal bacteria upon digestion
continues to attract experimenters Combining
chickens in germ-free cages and feeding them
with sterilized food. Prof. Schottelius has
found that they ate ravenously and evidently
digested well, but lost strength and flesh. Other
tests gave positive proof of the necessity of in
testinal bacteria to nutrition. Chickens Matched
in germ-free quarters thrived on sterilized food
for a week, when they began to decline in weight
and strength, and they were then divided into
group fed on sterilized food and one given food
containing bacteria. Those of the first group
all died in few days, while the others grew
rapidly and were soon indistinguishable from
other chickens of the poultry yard. These re-
suits confirm those of Nine. Metchnikof, who
has recorded greatly retarded growth in tad
poles kept entirely on sterilized food.
-
Those who peer into the future stop always at
one great calamity-the exhaustion of our coal.
What then? Mr.. Walter Rosenhain, an English
writer, points out that the suns heat may sup
ply vastly greater amount of energy than is
now yielded by coal, and that this may be used
at first for raising fuel plants or vegetable pro-
ducts giving large returns in heating power.
Under the pressure of necessity, means will
doubtless be found for getting even greater re-
turns from the solar heat by decomposing the
carbon dioxide of the air directly the air carbon
then serving as fuel. Already in Germany aico-
hol is being produced as q cheap fuel from pota-
toes, and it seems able to compete, with other
fuels eve7i9.ia land still having much coal and
little sunshine. In cloudless lands like Egypt
the suns energy, as Prof. John Perry has cal
culated, is nearly equivalent every year to that
of a layer of coal foot thick.
-
Reference to sounds attractive to mosquitoes
has led Dr. S. M. Lawrence, of Trinidad, to tell
of the influence of the human voice. As a boy,
he and his companions lured quickly-formed
swarms of the insects by note something like
a continuous "oo' pitched in medium key, and
then suddenly changed to lower 'ah," drawn
out in the same way.
Niagara Falls Excursions-Low-Rate Va
cation Trips via Pennsylvania R. R.
The Pennsylvania Railroad Company has Sc
lected the following dates for its popular ten
day excursions to Niagara Falls from Washing
ton and Baltimore: July "a, August and 2l
September and IS, and October 2 and 16. On
these dates the special train will leave Washing
ton at s A. NJ, Baltimore 9.05 A. NJ, York 1O45A A.
NJ, Harrisburg 114O A. NJ, Millersburg 1920 P. NJ,
Sunbury 1858 P. NJ, Williamsport 23O P. M, Lock
Haven sos p. NJ, Remove 1855 p. M, Emporium
Junction sos P. NJ, arriving Niagara Falls at 935
P. NJ. Excursion tickets, good for return pass
age on any regular train, exclusive of limited
express trains, within ten days, will be sold at
$40 from Washington and Baltimore; 1896 from