The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1898-10-09
SCIENTIFIC.


are made as small as one-sixth of an inch
In diameter.
whales weight has been estimated by
Nilsson at one hundred tons, equal to that
Of thirty-eight elephants.
The fieeting hues of the oap-bubble are
given by French chemist to paper by
coating the surface with a thin turpentine
damar varnish, which forms transparent
glaze breaking up the light rays
Salt made from aquatic plants and used
by natives of the Congo State has been
found by M. Leon FREDERICK to consist of
chloride and sulphate of potassium. This
iS taken as diSprOving Burgess idea that we
use sailor chloride OF sodium-to counter
act the effects of the potassium salts of
vegetables, and as indicating that salt is
taken with food for its flavor, it being with
out special action.
The production of acetylene from calcium
carbide is controlled by two French
physicists, Messrs. Letang and Serpollet, by
sleeping the carbide in hot concentrated
solution of glucose. When the prepared car
bide, after drying, is immersed in twice it's
weight of water, acetylene is given off in
the usual way, and at the same time
sucrate of lime is formed This the
gas to be given off with great uniformity,
stopping almost Immediately on withdraw
ing the water.
Varying results were reported from a late
test with Roentgen rays of 240 patients in
Paris institution for the blind. Nothing of
the three kinds of electro-luminous rays
was perceived by the totally blind, the
cathode and HuOreScent rays were diStin-
guished by those having a vague idea of
light and clearly seen by others with bet
ter vision, while others perceived one kind
OF rays only-the cathode or the fiuores-
cent The retina in some persons seemed
acted on like a Photographic plate
miniature forest of slender crystals,
shooting up at a rate plainly perceptible.
is the curious result of a slow combustion
Of aluminium noted by M. c. Margot, of
the University of Geneva. The well sand
papered metal plate is simply rubbed with
a mercury amalgam The extraordinary
eff1oresce1ce soon appears and reaches
height of nearly half an inch within half an
hour, the aluminium becoming perceptibly
warmer. The phenomenon ceases on apply
ing sufficient heat to volatile the mercury.
The effect is thought to be simple oxidation,
the mercury having a catalytic action, and
probably disintegrating the aluminium so
that 1t oxidizeS more readily. The expert
ment Is more uncertain with globule of
mercury on account of the difficulty of pull
verizing this and bringing it into contact
with the aluminium.
Although a new mechanical motion has
become very improbable kind of novelty,
an English inventors variable speed bevel
gear, an eliptical bevel wheel driving
conical wheel or vice versa. appears to diff
fer from anything hitherto attempted. The
shape of the pinion is the chief popularity.
On one side the teeth are carried further
toward the interSecting point of the two
cones. the extending teeth gearing with the
teeth on the short radius of the eliptical
wheel; the short teeth on the pinion, on
the other hand, gearing with the teeth on
the long radius of the elliptical wheel. While
the small wheel makes two revolutions for
each turn of the large shaft. one of the
wheels must run at variable speed. Credit
for this device is due the bicycle, the in
ventors aim being to cause the crank to
revolve more quickly when near the center
and more slowly when in the best position
for the rider to drive it.
The age of steel, according to Gustav
Lndenthal. is to be glorious but short,
probably the shortest in the history of the
human race-short, at least, compared with
the age of the Egyptian pyramids. The ex-
pectation of new ways of making iron and
steel with little or no fuel c2nnot be real
lied. Our coal fields must Inevitably be ex-
hausted in comparatively short period
variously estimated at four hundred to fif-
teen hundred years for Europe and Ameri-
ca and Australia. The use of iron and steel
on a large scale must then cease. Power
for meehanlcal purposes may be obtained
from the wind. tides, waterfalls and the
suns heat. but mineral fuel is the only
great source of power that can be used also
for reducing iron ores. When this is gone,
moreover, there can be no great develop
ment of power of any kind. as great ma
chinery without iron and steel is impossi-
BILE.
material lately introduced by Van
used in experiments with Roentgen rays is
reported to have proven much more sensi-
tive than any substance hitherto tried. 1t is
uranium ammonium fiuoride, produced by
dissolving one gramme of uranium nitrate
in four grammes of boiling water, adding
one and half grammes of ammonium
fiuoride and boiling a few minutes. The so
luton should be free from precipitate. On
cooling, octahedral crystals are deposited
within an hour, and the solution loses it's
pale yellow color becoming perfectly col
orless. The crystals are repeatedly washed
with cold water, bv which they are not af-
fected. although soluble in hot water The
preparation is dried and for luminous
screens is mixed with collodion or gelatine
The quality of these screens depends upon
the perfect development Of the crystals.
Smelling-one. of our three ways Of per-
ceiving objects at distance-has been
strangely neglected. so Prof. w. z. Ayrton
thinks Among his unexpected discoveries
is that metals have no odor, no particles
seeming to be disengaged, and the so-called
smells of copper and other metals being ev-
identity due to chemical action set up bv
the skin or In some other manner The
smell Of iron and steel held in the hand
seems to be due TO hydrocarbons resulting
Surprising also is the idea that doors do not
diffuse rapidly in sir, the scent az iii ~
lines recurring eighteen minutes to pass