Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1879-08-20
CURIOUS AND SCIENTIFIC.

CURIOUS AND SCIENTIFIC.
PROTECTING DRAWING INSTRUMENTS.
The most practical mode of protecting
Swiss drawing instruments from rust is
to coat the warm metal with very thin
lacquer of shellac dissolved in alcohol.
MOLLUsK SHELLS.
The shells of mollusks are worthless,
in Prof. Storer's opinion, for agricul-
tural purposes; but the shells of crusta-
ceans may be turned to good account, as
they contain notable proportions of
phosphoric acid, potash and nitrogen.
A LEAD TEST.
To test water to ascertain if there is
lead in it, evaporate a sample OF the
water nearly to dryness and mix the re-
mainder with small quantity of sui
phuretted hydrogen water (sulphydric
acid). The formation of precipitate
or cloud indicates lead.
ELECTRIC RESISTANCE OF WATER.
It has been found by Messrs. Exner and
Goldschmidt that the electrical resist
ance of pure water uniformly decreases
as the temperature rises; at 900 cent?
grade, it is about one-third of what it is
at 20o. A similar result is observed with
water calculated with sulphuric acid.
PUERPERAL FEVER GERMS.
It is believed b y Pasteur that he ha
discovered the germs which produce
puerperal fever and malignant pustule.
The primary organism which engenders
puerperal fever he describes as present
ing itself in the form of cells, united TO
each other in series of two, four or six,
and each having an average diameter of
two thousandths of a millimetre.
LIME WATER.
The lime water used with milk in the
treatment of nervous diseases is made as
follows: Place hydrate of lime in about
100 times its weight of water, in short
time saturated solution, known as lime
water Qiquor calcis, B. P. and u. S. E. }
results. 1t contains about 16 grains of
hydrate of calcium (Ca2HO), equivalent
to about IL or II grains of lime (CaO)
in one pint.
CHROME BLACKS.
In dyeing chrome blacks upon wool,
Reimann considers that chrome-alum-
now residual product from the manu-
facture of alizirin-may be partially sub
stituted for potassia chromates. He re-
commends also mixture of chrome
alum, iron-alum, and tartar, followed up
with logwood, as yielding black which
combines the advantages of the chrome
and the iron blacks.
ABOUT SILK.
Besides the insoluble fibre, silk con.
tains soluble substances, which give it
its brightness, color and strength. It is
of Importance, therefore, that the natu-
raj gum or varnish should be softened,
but not dissolved, before the cocoons are
unwound. Hard water is found to mini
mize the loss of the soluble substances
and at the same time soften the cocoons
sufficiently for the unwinding process.
When hard waters are not obtainable
from natural source, it is recommended
to modify the soft waters by the addition
of sulphate of lime and carbonate of
soda. IL the silks are to be dyed bright
colors, it is desirable that they be spun
out of soft water.
HIGH RAILROADS.
Railroad engineers have not only the
tunneling tendencies of the mole, but
far more than the aspiring tendencies OF
the most ambitious squirrel. Some
German has given the following as the
highest points yet reached in carrying
railroads over mountain ranges OF
through elev ted passes: The Apennine
line reaches a height of 1924 feet; the
Black Forest line, 2,789 feet; the Sem.
mering, 1920; the Caucasian, 3,198 feet;
the st. Gothard (tunneD, 1886 feet; the
Bremen, 4,475 feet; Mont Gents (tun'
neD, 1890 feet; the Northern Pacific,
1924 feet; the Central Pacific, 1921
feet; the Union Pacific, 1878 feet; and
the Andes road 16, 646 feet.
WHAT SMOKING DOES FOR BOYS.
A certain doctor, struck with the
large number of boys under fifteen
years of age whom he observed smoking,
was led to inquire into the effect the
habit had upon the general health. He
took for this purpose thirty weight boys,
aged from nine to fifteen years, and
carefully examined them, and in twenty
seven of them he discovered injurious
traces of the habit. In twenty-five
there were various disorders of the circu-
lation and digestion, palpitation of the
heart and more or less marked taste for
strong drink. In twelve there was fire.
quent bleeding of the nose; ten had dis
turbed sleep, and twelve had slight
liberation of the mucous membrane of
the mouth, which disappeared on ceasing
from the use of tobacco for some days.
Medical treatment was of little use till
the smoking was discontinued, when
health and strength were soon restored.