The daily Cairo bulletin. (Cairo, Ill.) 1878-1???, 1880-11-23
POPULAR SCIENCE.

Gerard-Lescuyer finds that when
the current from q dynamo-electric
machine is sent into n magnetic cleo
trio machine the latter moves with
increasing speed, then it slackcns,
stops, and turns in the opposite direc-
ton, and so on. The polarity of the i'll
ductors is reversed.
j. A. Pabst publishes this continue
Gus method of preparing acetic ether
lie introduces intoa retort cold mix
ture of So C. c., Of sulphuric acid, and
the same quantity of alcohol. When
the mixture has arrived at the tempe
nature of 140 degrees centigrade, he al
lows to flow slowly into the retort q
mixture Of equal equivalents Of alco-
hol and glacial acetic acid. At first a
little sulphuric distils over, and there
then passes liquid containing So per
cent. Of acetic ether.
An improvement on the Bunsen
photometer has been devised by Herr
Teplcr, and it is no longer necessary
to use but one eye or that the observer
take certain determined position.
The ordinary thin sheet of paper with
the oil-spot is replaced by two thin
sheets of parchment paper placed one
on each side of stout sheet Of paper
perforated by hole about an inch in
diameter. The sheets are stretched on
frame between two sheets of clear
glass. When the lights are properly
opposed, the hole in this arrangement
disappears, just as the oil-spot does in
the old device, but with much less in
convenience to the observer.
An exchange publishes the follow
ing as q means of silvering by cold
rubbing: Make paste by thoroughly
grinding in porcelain mortar, away
from the light, water, 3 to ounces ;
chloride of silver, Z ounces potassium
oxalate, 1915 ounces; common table
salt, 10 ounces, and sal ammonac, 3.75
ounces. Or, chloride Of silver, 81
ounces; cream Of tartar, ounces ;
common table salt, 1915 ounces, and
water enough TO form paste. Keep
the paste in covered vessel, away
from the light. Apply it with cork
or brush to the clean metallic "copper"
surface, and allow it to dry. When
rinsed in cold water the silver pre-
sents o fine frosted appearance, the
brightness of which may be increased
by immersion for q few seconds in d.
lute-sulphuric acid, or in q solution
of potassium cyanide. The silvcring
bears the action of the wire brush and
of the furnishing tool very well, and
it may also be "oXidized."
M. LcssertcW, says the British Med
ical Journal has just given publicity
to a plant which has great reputa-
ton as q cure for rabies in the king
dom of AMMAN. This plant, of which
the name is hoang-nan. is kind OF
Llama, closely akin to the false angos-
tura its effects are similar to those of
strychnine and brucine. M. Boulcy,
in speaking Of this new remedy in the
Recent lie Medicine Vctertnaie, re-
grcts that no facts corroborativc of It's
ciiicaciousness are given, but is OF
opinion that the property recently
shown TO belong to rabbits, Of east y
contracting hydrophobia by inocula-
ton, should be utilized for making cx-
permcnts thus so easily performed
In reference to this subject, NJ. Bouley
related an anccdotc about garlic, q
substance which has always had q
great reputation among remedies
against rabies, and is constantly found
rs a principal integral portion in d
large number Of fornule long kept Sc
cret. A young man had been bitten
by mad dog, and symptoms of rabies
speedily appeared. His family, in Il
state Of the greatest alarm, scarcely
knowing what to do with the sufferer
shut him up in u loft where some gar
lie had been left to dry. in his delir-
ium the poor fellow seized the bun.
dies of garlic, ate ylccdily Of them, and
coon became exhausted and fell into d
deep sleep. When he awoko he was
cured, and the symptoms Of rabies had
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