The Princeton union. [volume] (Princeton, Minn.) 1876-1976, 1880-10-07
POPULAR SCIENCE.

The electric light is being fitted to
alldepartments of the British museum.
The temporary fittings made to exper-
iment with have been removed.
"Tonic glycerine' consists of 1900
grammes Of pure glycerine, 80. drops
Of tincture Of iodine, and 80 cent?
grammcs of iodide Of potassium. 1t
is a good substitute for cod liver oil,
and the dose is q tablespoonful quar-
ter Of an hour before each meal. b.
It is important in workshop mani
pulation to remember, that, if piece
of cast steel be made red-hot and
quenched III cold water, it will be-
come longer, but, if the same opera
ton be performed on a piece of
wrought iron, it will become shorter.
It seems that the original inventor
of the glue, glycerinc, and water pro-
cess of copying letters, which has
been extensively introduced within
the past few years, has obtained in
this country Il patent for his device,
dated May ii, 1880. He obtained a
patent in Germany two years ago.
A very favorable report Of tests of Mr..
lamp is published in the June num-
Der of the american Journal Of ISci-
ence. The experimenters were Profs.
Bracket and Young. A horsepower
was found capable of maintaining 1912
lamps of 1917 candles each.
An infusion Of about pound of
quassia chips to eight gallons of water
has been found very useful in prevent
ing blight in peach-trees and vines.
If some of the infusion is put upon the.
hands and face after washing there
will be very little Inconvenience felt
during the day from the attacks Of
mosquitoes, gnats, or other insect
pests. .....-- ..........
Bromine is likely to go into extern
siveus as 4 disinfectant, now that it can
be had in a solid form, or, more strict
| ly speaking, as 4 compound which
readily yields the bromine, and which
can be easily transported. A PIus-
sian chemist has hit upon the happy
idea of causing bromine to be absorbed
| by silicious mari orsthe shells of in
fusoria, which has been employed to
take up nitro glycerine in order to
make dynamite.
This is all easy way of detecting the
purity or adulter ltion Of a sample of
wine: Dip a small sponge into the
wine to be tested. Place the sponge
then in q saucer, the bottom of which
is covered with a small quantity of
water. If the tWinc is pure, it will
take from quarter to half all hour
before the water in the saucer becomes
| colored, but if the wine is not pure,
the coloring of the water takes place
Immediately. .~
The Druggists Circular says that a
mass resembling India-rubber, and a
soluble in linseed oil, may be prepared
by heating in al iron kettle, which
should be only half filled, ten pounds
Of sulphur and twenty pounds of rape
seed oil, with constant stirring until
the sulphur is melted and the mass be-
gins to swell, when it is poured into a
mold busted With some kind Of pow
der, and allowed to harden. Linseod
Oil may be used instead of the rape
seed oil, but then the quantity of sui
1. phur must be reduced.
! A recent report on Injurious insects
states that the popular idea that grubs
arc killed by extreme cold is not borne
out by facts. An examination of the
larvae and pup9 that had been fully
exposed to the influence of frost show
ed that they We're uninjurel even
when the earth containing them was
frozen so hard that the mass had to be
broken With. q hammer. Frost, then,
! instead Of diminishing the number of
insect pests, has a tendency just the
other way. For, not only does the
frozen Garth, afford . safe, retreat to
the grubs from the attack Of birds, but
excessive and prolonged cold prove;
fatal to tho birds themselves. ~.