The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1900-09-01
Corysspondsnes Baltimore County linton.
SCIENTIFIC MISCELLANY.

10 Distilled Water-An Inclination Hy-
drometer The Naples Sap-Etching
by ectricity-Aeration From q New
Source-A Harmless Depilatory-Pho-
tographs In Relief Phosphorescent
Glass-Water in Soil.
The extraordinary behavior of the magnetic
needle in the province OF kursk IN hussia ~
physicists. magnetic survey was hfst made
by Prof. Moureaux, who made observations at
100 stations, and In the small plateau or ABOUT
two square miles between the Plota and Solo
tinka rivers he found variations in declination
from 3lo E: to 960 W, and in inclination from
49, to 790, these inclinati0ns being respectively
those normal to Morocco and Spitzbergen. The
question has since been taken up by Prof. Leyst
Of Moscow, who has noted point near kotche-
towka where the dipping needle reaches the
vertical. The region is a rolling country, with
fertile black soil resting on cretaceous rock,
and explorations to depths OF 900 feet have
failed to reveal any iron.
The late assertion that distilled water acts as
poison on account Of its powerful solvent pro-
water has appeared to stunt the grown Oh
roots, but NJ Victor de Cleves. a French botan-
list, has now shown that while the roots OF
sprouted wheat stop growing in commercial dis
titled water, on reaching length OF perhaps an
inch and grow in spring water to II TO 10 incnes,
after that has been redistiled in glass. The
poison is from the copper still used for CONNER
cial distilled water.
The ordinary hydrometer is vertical float,
with scale to measure the depth TO which II
LIQUID A new instrument measures the den
sity by the inclination of float, and, as the
readings are not affected by caplliarlty. u Is
much more accurate than the common form,
and is capable of wonderful sensitiveness.
The flow Of sap in the maple in spring has
been experimentally shown by Mr.. w A. Orton
to be phenomenon of physics rather tnan OF
plant physiology. The sap is expelled BY the
expansion, caused by warmth, OF the gas con-
tanned In wood cells.
The engraving of metal dies by electrolytic
etching Is a new process that a German COM
pany expects to work extensively. A plaster
negative of the original is saturated with the
of a source of electricity. the metal plate to be
etched being attached to the positive pole; as
the cast and the plate touch, the cTcuit t Is
points of contact. To get good results, the con-
facts must be but momentary, the insoluble
particles in the metal being 1rusnea away ai.sr
ing at the same points is effected by an auto
matte machine, which also operates the brushes:
an inch requires 600 to ZOO contacts, of about IL
seconds each. the whole process occupying or
hours. The best electrolyte for etching steel
is a ten per cent. solution of chloride of ammo
MUM with little hydrochloric acid, and the
best current is 1.3 amperes per square inch. at
to IL volts, but the voltage must be smaller at
the beginning, when only the points Oh the
negative cast touch the metal.
AFs
Waste carbonic acid from fermentations is
now being converted into valuable product at
Rouen, in accordance with suggestion by ID.
Louis Mems. A distillery producing about
5000 gallons of alcohol daily has been throwing
off into the air each day more than 30 tons OF
carbonic acid gas. and this is now collected by
system of exhausters and liquefed In steer
cylinders under q pressure of So atmospheres.
The uses of the liquefied gas are important. 1t
offers especially the most convenient means OF
charging soda water and other beverages. ana OF
producing intense cold Tor various PURPOSES
The experience of Dr.. Neville Wood leads
him to believe that superfiuous hair may DC
safely. painlessly and permanently removed Dy
80 to 40 exposures of 10 minutes each to Roent-
gen rays. In the case of q woman with marry
growth on the face, all but nine hairs were re-
moved by As sittings at the rate of 10 a week
and these remaining hairs dropped out week
later. A lead-foil mask protects the unanecteo
skin.
A teaspoonful of acetate of zinc in q. wash
bowl of water is an effective bath for chilblains
giving relief when all other remedies 1aii.
A valuable process for converting photo
graphic film into photO-plastic relief. which
may be used for moulding glass and many 0tner
purposes, has resulted from an accidental dis
cOvery by NJ. SekutOwiz. To reinforce mega
tive film, it was placed in solution OF mercury
bi-chloride. when q surface of more than
unusual relief was produced. Seeking the
cause, the experimenfer found that mistake
strength. and further trial proved that the de-
gree of relief could be varied according to the
concentration of the bath. To utilize the dis
covery, plaster impression was at once made
The wet film was placed upon the moistened
plane surface of block of fine plaster, and IN
few minutes was firmly fixed to this support,
the side in relief being uppermost. A layer OF
plaster flowed over this gave reproduction
that served for making copper mOulds by the
usual galvanoplastic treatment.
-
Luminous glass letters for street names, house
numbers ETC., are successful German product.
They are made in all colors from pressed glass,
Oe y chemical factories 81. rue tin backs ara
nailed to the wall, the glass being then fastened
to the tin by pin with screws. Being protected
from air and moisture, the luminous substance
lasts long time, and is much superior to coat
ings of luminous paint.
sFs
The percolation experiments made at ROtham-
stead for about twenty years have shown that
in the winter months more than half the
amount of rain penetrates the soil and is avail
able for springs, while In summer this amount
only reaches a quarter that of rain. Three
gauges were used, each having an area OF one
thousandth of an acre. The water was col
lected at three depths, and was always greater
in quantity at 40 inches than at 20 or at 60.
80
The ingenious machine of Bavarian inventor
sorts steel balls by causing them to rebound
from an impact surface. Only perfect balls
have sufficient elasticity to clear fixed barrier,
while cracked or badly hardened ones will strike
the barrier and fall back into another compart-
ment.