The citizen. (Frederick City, Md.) 1895-1923, 1897-09-03
written for the Citize.p.)


oxygen. BY the recently perfected pro-
cess of Prof. Linde, of Munich, a
pump of five horsepower eondenses
the air to pressure of 200 atmospheres,
the air passing down spiral tube and
expanding with the production of
great cold, on being admitted to
chamber surrounding the spiral. Each
instalment of air pumped in further
cools the spiral, until in few minutes
the air escapes into the chamber in
liquid drops having n temperature of
2730 below zero. This process is said 10
have reduced the cost in Germany
from about 1925 to 24 cents for each
five cubic meters reduced, and the sud-
den cheapening of substance of such
varied possibilities is expected soon to
bring about many industrial changes.
Photographers are said to be able
sometimes to produce direct positives
by extreme over-exposure or 10y special
treatment. AnthORy'S Bulletin calls at
tention to the remarkable experience
of beginner, who obtained three pos
| itives and one negative from four ex-
posures of the same subject, the only
| difference in conditions being the
length of exposure. The one good,
clean-cut positive of the three was pro-
duced by an exposure of a minute and
quarter with fairly large stop in fnll
daylight. In another experience men,
toned, two exposures of the same sub.
ject under precisely the same condi-
lions of Lighting and timing produced
one positive and one negative, although
developed in the same tray at the same
time.
Fruit trees along highways and even
railroads have become source of rev.
enue to some German States, and in
the grand duchy of Luxembourg spe clal
ing inspectors and road hands in the
planting and care of orchards.
Several substitutes for glass are now
made in Germany. IectOrium is BIZ
cromated gelatin everything on both
sides web of galvanized iron or steel
wire, and is made into sheets about a
sixteenth of an inch thick. 1t is lighter
than glass and practically unbreakable,
1t may be bent, is easily repaired, and
is poor COO luctor of heat and cold
1t is about as translucent as opal glass. |
Its disadvantages are inflammability
and liability to soften Oh warm DAYS.
A material for lighthouses is FenSter-
papl)e 1t is a tough manila paper
made translucent and impervious to
water by soaking in boiled linseed oil
N do L.,
said to cost only about one-hundredth
as much as glass, while it is durable
and not readily damaged. 1t requires
no shading from hot sunshine, yet at
all times admits sufficient light for
growing plants. A more recent pro-
duct is HorngLdS. This resembles tee
forum, but is claimed to be more trans
parent and to soften less readily on
heating.
A new element, bythium, is claimed
by Theodor Gross, German chemist,
to have been obtained from sulphur
On electrolyzing fused mixture of sill
yer sulphide and silver chloride in a
nitrogen atmosphere, he obtained
dark gray powder, insoluble in aqua
regia and in ammonia. Fused with al
kaline carbonate, this dissolved in n.y.
drocloric acid, from which hydrogen
sulphde gave brown precipitate. The
new substance equals five per cent of
the original sulphur used, and AS there
is not only corresponding loss of sui
phur but a smaller loss of chlorine, the
possibility is admitted that bythlum
may have come from the decomposi-
ton of chlorine instead of sulphur.
The fascinating idea that each dis
ease microbe has its one specific poison
Gus principle, its toxin, is attacked by
NJ. A. Charrin, French biologist. He
shows from experiments that single
! microbe species may produce several
j pathogenic compounds-the bacillus of
pus, tor instance, yielding several,
which are easily distinguished by their
pathological effects.
|
Experiments have shown that the
ash constituents of coal, which are not
readily permeable, may be roughly es-
/ timated by means of ROentgen rays on
comparison with slabs having known
percentage of ash.
One of the most curious and inter-
estiDg of the electrical exhibits at the
Royal Society's last soree was that of
! Mr.. J. w. Swan. It consisted of dishes
containing resin covered with beauti.
| full and complex patterns that had
been produced by placing the resin be-
tween two poles of an induction coil in
action. The spark-which was taken
between an auxiliary pair of terminals
did not pass TO the resin, which was
merely subjected to strain. Notrace of
any effect appeared on the resin when
removed, but on being warmed
through, the surface puckered up into
patterns as the mass softened, the in-
ternal strains set up by the electric
stress seeming to be unable to fiud re-
lief while the resin is hard. The pat
terms at the negative pole differ from
those at the positive pole. The strains
persist for long time, some of the pat
terms shown having been developed
three months after the resin was cleo
trified
An immense electrical influence ma
chine has been constructed by Mr.. Jas.
Wimshurst, whose name is so well
known in connection with apparatus
of this kind. 1t is duplex in form, a
shaft on each side carrying twelve
plates 36 inches In diameter, each
plate with 80 sectors. The machine is
certain to excite itself before the hand
crank has made complete revolution.
1t gives torrents of electricity, the
length of the spark between the two
| ,fs.r tor 10 kat fs,al