The Democratic press. [volume] (Ravenna, O. [Ohio]) 1868-1901, 1880-10-28
POPULAR SCIENCE.

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Recent experiments by Piazzofi apsa
pear to establish the fact that the to-
nacity Of iron increases on magnetiza-
ion. tsaeld al
A new process of refining copper is
reported from Germany. 1t is using
the phosphide of copper- or Yphos-
The common grinding and polishing
of glass articles, for various uses is ef-
fected by revolving wheels of iron,
and supplied with a stream of water
from q hopper or can above the wheel
A good paint for wire-work is made
by boiling linseed oil with rs much
litharge as will make it Of the consis-
add lampbiack at the rate Of one part
to every ten, by weight, of ithArge;
boil three hours over q gentle fire.
The first coats should be thinner than
the following coats. .ssss.., s,~.s9v7,
The uniform appearance Of the mi
croscopic shells. and the almost total
absence among them of any sediment
from the sea of foreign NATTER, aug
gests most forcibly the idea of perfect
repose ut the bottom of the sea. Some
of the specimens are as pure and as
free from sand as the fresh h-fallen snow.
flake is from the dust of the earth.
A new an@sthetic4 by w. b. Mac
Edinburgh Odonto Chirurgical Socie-
ty. It consists in combining the adj
ministration or exhibition of ethylen-
dichloride with nitrous oxide gas; and
this is effected by placing . small
quantity of the ethylcn-dichloride OIL
u little sponge held by q clip in the
way-tube of the nitrous oxide inhaler,
leaving space enough on each side of
the sponge for the free passage of the
nitrous oxide.
Nitro G Glyccrine is produced by mix
ing glyccrine with nitre and sulphuric
acid most dangerous aud explosive
compound, much more powerful than
gunpowder. 1t is used mostly for
blasting purposes In mines and quar-
ries. The pure glycerine Is q sweetish
liquid, without color or smell, and is
distilled from many fats and oils. It
will keep meat, fruit and flowers from
decaying, and natural history speci-
mems are often preserved in it! As it
does not freeze easily it is added to
water i'll gas metres. The Russians
rub it Oh the face in Winter to prevent
being frost-bitten in exposed parts.
Herr Bottger says that there is no
method SO convenient and SO sure as
that by glucose in alkaline solution
for reducing the salts of silver. Take,
for example, chloride of silver freshly
prccipitated and we'll washed. suspend
it i'll a sufficient quantity of diluted
caustic soda, and add small portion Of
glucose. In few minut tes, upon boil
ing, the reduction takes place. The
silver can be collected, washed, and
slightly calcined, in order to obtain
the metal pure under the form of
light sponge of dull white. The
same methOu furnishes an exceedingly
active platinum black, and with The
salts of copper it gives an oxide of q
beautiful red. = t21s.' ti -
DR.. Huggins has found that certain
stars, such as Vega, give 2 complete
spectrum of hydrogen; others, more
yellowish in color, such as Sirius and
Ursa Major, shows thinning of these
lines; others, again like Arcturus,
Aquila, and Virginius show the in
trusion of more refrangible lines whilo
Capella gives q complex spectrum like
that of the sun. The spectrum of the
flame of spirit lamp presents q strong
group of lines, aud he considers
It to represent the light emitted by
the molecules of water. The spectrum,
he considers, q very sensitive test OF
the presence of carbon. These results
were lately illustrated by him at a
meeting of the Physical Society, LON
don, by Photographic spectra taken ac-
cording to his new method.