The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1905-02-04

remarkable testof copper tubes in loco
motive boiler has been described by F. W. Webb
The boiler received set of 1893 tubes by ten
makers, the tubes being arranged in groups of
ten Of different kinds so as to give similar treat
ment to all, and the engine was run 1898 miles
in period Of ten months. The first tube failed
at 81, 067 miles and the second Of the same make
at 4O.0l2 miles, all tubes of the same type being
removed after the failure of two. The best type
showed no failure until after 1896 miles, The
failures. with one exception. were at the bottom
of the tubes and within six inches of the fire.
box end. Analyses indicated that the best
tubes contained either per cent. Of nickelor at
least 05 per cent. Of arsenic, and copper tubes
hardened with nickel are being tested on a lead
ing English road.
&c
The mystery of magnetism is not lessened by
DR.. r. Heusler's discovery that magnets may be
made by combining non-magnetic metals. The
magnetization of a tool of Manganese and tin was
accidental. and experiments then showed other
magnetic alloys, one Of maganese aluminium and
copper rivaling cast iron In its magnetic proper
ties. Other interesting facts have been revealed
"a manganese-lead magnet. for example, losing
its magnetism at 1lO' f.
-
The emanium of +. Giesel is hypothetical
radioactive element supposed to be allied to
lanthanum. It colors bottles violet, causes
paper to become brown and crumble, and
reaches its greatest activity In a month after
precipitation from solution. Attempts to iso-
late it from ianthanum preparations are being
made.
An official laboratory for satisfying physicians
Of the properties Of new medicines is a Bordeaux
chemists idea.
Many substances besides carbon have been
tested by G. P. Eteinmetz as electrodes for arc
lamps. He finds that magnetic, the black oxide
of iron, is especially suitable as it conducts
well, is stable at all temperatures is very plenti
full in nature, and gives white arc of much
higher efficiency than the carbon arc. It forms
the negative electrode, the positive being
copper sagment of such size that 1t does not
wear away from over-heating yet becomes
sufficiently hot to prevent the deposition of
fused drops of magnetic from the negative
electrode. The magnetic burns at the rate Of
an eighth of an inch an hour, the rate of the
fame arc being from one to two inches per
hour. and with small sacrifice of efficiency, the
addition of substances like titaDium compounds
reduce the burning of the magnetic so that an
eight-inch electrode may be produced that viii
last 500 or 800 hours.
novel experiment in hygiene is the new
forest school" of Charlottenburg, suburb of
Berlin. School, domestic and recreation build
ings have been provided in pine forest and tits
the purpose to have pupils and teachers remain
throughout the day, two and one half hours daily
being given to ordinary studies, with open air
instructions in natural science, gymnastics and
singing, and the balance of the time to be spent
in the playground and forest. A trained nurse
is to oversee the food, with the aid of visiting
medical man. The school has opened with 100
feeble and anaemic pupils from the municipal
schools, and the effort to give these children
physical and mental strength will be watched
with interest.
In his new line of research, Sir James Dewvar
has found that charcoal-especially cocoanut
charcoal-absorbs large amount of gases when
cooled to liquid air temperatures. When a con-
tinuous current of air was passed over the
chilled charcoal, the escaping gas was at first all
nitrogen, and in quarter Of an hour the gas
held by the charcoal contained as much as 90
per cent. of oxygen. A nearly perfect vacuum
was obtained by immersing in liquid air a tube
partly filled with cocoanut charcoal.
The plants used as substitutes for soap have
been investigated by s. Rosenthaler. These are
especially numerous among the leguminous
plants, with albania and acacia at the head of
the list. The roots and root stalks and bulbs are
mostly used, then the bark, and sometimes the
leaves and fruit. An East Indian plant sup
plies blossoms that may be employed. The
cleansing property Of the plants seems to be
due to saponine and to depend upon the produc-
tion by this substances of very finely divided
particles in the form of an emulsion. The vege-
table soap is claimed to have the advantage that
being neutral or slightly acid-it contains no
free alkali to njure colors. 1t is stated that one
plant alone-nausd pdradisiea- sap containing
sodium oleate, and that it serves as soap without
containing saponine.
A medical man of Upper Silesia has reported
that his attention was early attracted to the
freedom Of his district from lung troubles. He
found even that consumptives coming from
outside soon regained their health without
treatment, and, as the air is constantly laden
with coal-dust from the neighboring mines he
infers that this dust everts drying and disin-
fecting on tubercle developments in the lungs.
The theory is to be tested in a new local sani-
tarium.
The risk of gangrene from carbolic acid dress
ings is not generally appreciated by physicians,
in the view Of DIR. g. E. Shoemaker. Harm does
not usually follow the applications, but one
author has found recorded l82 cases of gangrene
from dilute solutions of to per cent applied
for about twenty-four hours. The effect is
produced without pain.
Ass
On the principle of the dynamo, M. Guarini
thinks, the earth's rotation should induce in the
atmosphere an electric current going in inverse
direction and in the earth's crust one in the
same direction as rotation.
VIM. *. BURNS,