The citizen. (Frederick City, Md.) 1895-1923, 1896-03-27

eXekcise Defective development-sucn'
as imperfect proportioning of the fea-
lures and parts of the body-is often
associated with dizziness, but the want
of physical training of the brain is a
more general and direct cause of the
dullness.
The first boiler insurance company
was formed in England in 1859. In the
ten years following, according to Mr..
r. b. LOngbridge, the annual average
of explosions of land boilers was 40,
and the average number of deaths IS,
whereas for similar period ending
June 80, 1895, the average number of
explosions, including collapse of fiues,
was 1854 and of deaths 1853. This COM
parisOn becomes much more striking
when one considers the enormous in
crease in the number of boilers and the
steady increase in steam pressures.
Four sensitive plants, alike in size
and age, were placed by M. Flammar-
ion under glass of different colors. AT
ter six weeks the plant in red light
was twice as large as any of the others,
that under green was next, but that
under blue showed no growth. The
red plant was healthy but abnormaliy
nervdtis. curling up at breath, while
the plant in white light, though third
in growth, was strong and vigorous.
Until now the familiar process known
as the "retting" of flax has not been
understood. After long experiment,
Prof. Winogradsky, of ST. Petersburg,
has isolated somewhat large, spore-
forming bacillus, which proves to he
the specific microbe that acts upon the
flax.
Lithium is a rare but widely diffused
metal, resembling potassium and sodi-
UNI, and remarkable as being the light
est known solid not containing air. its
specific gravity being only 0.59, or a
little more than half that of water.
SoIue interesting compounds have been
announced by GuntZ, Il French Chem
list. 1t is the first substance known to
absorb nitrogen gas at ordinary tent
peratures, lithium proving 10 be capa-
ble of absorbing it rapidly at temper
| allure below dark red. Deslandres has
verified the discovery, and made use
of it, in separating argOn from the at
mosphere. Continuing his expert
ments and wishing to heat some litbi-
um in an inert gas, GuntZ raised the
metal TO bright red III current of
hydrogen, when, to his astoDisbment,
the whole took fire and burned up, de-
posting a white powder. Analysis
showed the powder to be bydrde of
lithium. 1t is more staple than pre-
viously known hydrides of the alkaIi
metals, and when treated with water
it yields the remarkable proportion of
One-fourth of its weight of hydrogen,
or more than three hundred gallons To
the pound.
The first edition of Prof. G.. A.
Young's WORK on The San, published
in 1881, mentions 81 elements as bav-
ing been detected by the spectroscope
In the sun. In all of these $50 lines
had been identified. The new edition.
of Prof YOung's book states that Prof.
Rowland has now compared go ele-
ments with the solar spectrum, and
established the existence of SO of them
III the sun, being doubtful in regard to
of the others. OF iron lines alone he
has identified more than 1000
X
An apparent cold sensation has been
noticed when the hand is exposed to
Roentgen rays. Testing this with the
thermopile, DIR. Turner, of Edinburgh,
has found that heat is really radiated
from the phosphorescent patch in the
Crookes' tube, but that the heat is
much lessened if the current is revers-
ed SO as to change the poles. The phos-
phorescent patch in some tubes be-
comes quite hot.
The need of a universal screw-thread
is felt more in Europe than in the Uni
ted States, where only one standard is
now used. At an International Con-
ference soon to be held in Berne. the
French Admiralty thread, similar in
shape to the American but based on
the metric system, will probably be
urged for adoption as the standard of
all countries.
1t has been regarded as a curious
fact that lightning has preference for
certain trees, giving first choice to the
oak and seldom touching the laurel.
During the last score of years the SUBJ
ject has been made one of systematic in
vestigation in a German forest. In the
district under observation, every 100
trees includes an average of about 20
beeches, IL oaks, Is pines and frs;
yet, in the years 1879 to 1890, lightning
struck Sc oaks. 3 or pines, and 20 or
81 frs. but not single beech. Trees
on wet ground were very often struck,
disproving the idea that dryness of the
soil adds to the risk. Early expert
Inents showed that the oak is much
better electric conductor than the
beech, but that the moisture in living
wood has nothing to do with the con-
ductivity; while the recent results in
dictate that the trees containing the
largest proportion of fatty materials
are most secure against lightning, and