The Democratic press. [volume] (Ravenna, O. [Ohio]) 1868-1901, 1881-05-05
SOIENTIrIO.

The Hotchkiss revolving gun already
| adopted in the French and other great
navies. has hcen ordered for use lately
| in the German navy, the ships to ''be
| armed with this weapon in such a man.
| ner that every point surrounding each
| vessel may be protected by the fire OF
at least two guns at a minimum range
of 200 metres"
1. has generally been supposed that
when carbolic acid is mixed with chlor-
ide of lime the former is liable to be
destroyed by the latter, with loss of &C
tivity on the part of both, when applied
for disinfecting purposes. Diamin finds,
however, that mixture of these two
substances possesses notable greater
antiseptic energy than either of them
has separately.
A common process for discovering
the presence of vegetable fibre in wool
en- goods is to take half dozen sticks
of caustic potash and put them into a
gill of water, which boil. Put the
let it remain for about twenty minutes,
in which time all the animal matter will
be dissolved, and that of vegetable
will remain intact.
At the last meeting of the Maryland
Academy of sciences DR.. Theobold
showed species of a beetle (bOlbo
ceyus fdrctus) which was observed by
him to move small tray. He gave
the following interesting figures: Weight
of beetle, 2 grains; weight moved, 81
ounces-2, $40 grains, or 1920 times
the weight of the beetle. A man weigh
ing $50 pounds, endowed with the
strength of this insect, should, therefore,
be able to move $4,000 pounds, or
nearly 100 tons.
The so-called Spence's metal, says
Prof. j. w. Mallet, in the American
Chemical Journal, q fused mixture of
iron pyrites or other metallic sulphides
with excess of sulphur, seems worthy
of some attention. especially for making
the joints of water-pipes, ETC., although
the claims put forward on its first an
nouncement were rather extravaganza.
Its melting point is reported as low as
100 degrees centigrade, it has con-
siderable amount of cohesive strength,
it resists exposure to air and water,
and it costs very little.
1t has not been supposed that sewage
gas could exert anX corruding influence
on metals, yet Investigations show that
holes are actually worn in lead and
zinc pipes by such gases. From all
that appears, the gas which proceeds
from the drain is the most dangerous
element-exhalations of this character
exercising their daily influence both by
pertorating the pipes which contain
them and then issuing through these
apertures to mingle with the respired
air. Substantial iron pipes, well VEN
tilated and joined in the most perfect
manner possible are considered the best
protection.
There is new instrument going into
use in England for the purpose of re-
ceiving Greenwich time signals at tele-
graph stations, etc. Hitherto, the pas
sage of the time signal current along
the lines gave no other indication of its
presence than detection of the
needles of ordinary instruments and
corresponding movement of the arma-
ture of the Morse ink-writer, and
sounder, ut 10 A. NJ, and the eye had
to be kept constantly on the instrument
to learn the exact time. In the new in-
strument there is an arrangement
which rings a bell and ut once arrests
attention when the first part of the time
signal is transmitted.
A patent has been obtained in Ger
many to produce tannic acid in the
form of crystalline needles. For this
purpose q spirit, or ether solution of
tannin is evaporated in a copper vessel,
OF in vacuo, till n sample, when cold.
can be broken without adhering TO the
fingers. This mass is brought into Il
vessel provided with a double bottom
for the admission of steam, and con-
tanning a number of holes through
which the warm and therefore soft tam
mic acid goes, and as the apparatus is
five metres high it forms thin thread.
This falls through tho warm apparatus
on a wooden or metallic cylinder, kept
in quick motion, from which the thread
ia taken and broken intO small bits