The citizen. (Frederick City, Md.) 1895-1923, 1899-08-25
Written for the Citizen. J

anauluul, JHOuSH MluclN us
tributed in moderate quantity,
has attracted little attention. 1t
is silver white metal, has the
high melting point of about
10000 c., is somewhat lighter
than zinc, oxidizes slowly III the
air and violently in nitric acid,
and is little affected by Sulphuric
and hydrochloric acids and aka
line solutions. 1t has been pre-
pared with difficulty by reduc-
ton from the dichlOride in hydro
gen. Until now attempts to- de
post it electrolytically have been
unsatisfactory, but Mr.. Sherard
Cowper Coles has at last succeed
ed in getting brilliant deposits
from a solution containing |
ounce of the metal TO the gallon,
prepared by boiling 10 parts of
yanadic anhydride in 2 parts OF
caustic soda and 100 parts of
water, afterward adding 81 parts
of hydrochloric acid. Nanadium
is found to increase the tensile
strength and ductility of iron,
copper and aluminium. The pres
ent use of the metal is almost eX-
clusively confined to convert
ing aniline into fixed black dyes,
and the col0ring Of glass, but i'm
portant new applications are cX-
pected to follow its practical
electro. deposition.
a new mirror, having advanta-
yes where extreme lightness is
essential, has been submitted to
the London Royal Society by Mr..
A. MallOck. 1t is made by tax
ing a ring Will accurately ground
edges, and stretching upon it the
thin film left on the surface of
water after few drops of Solu-
ton of pyroXyline in amyl ace
tate have been allowed to spread
there and evaporate, the film be
ing then carefully silvered. A
mirror two inches in diameter
can he made of less than ten
grains in weight.
A miniature telephone is the(
aid to impaired hearing devised
by Mr.. Il. IL. Collins, MaSSa
chusettS inventor. A small re
ceiVer, adapted to he inserted
into the passage of the ear, is
connected by wires with small |
transmitter worn upon the breast,
and with a battery and induction
coil carried i'll the pocket.
The rodents are the most nu-
merouS family of mammals, and
the number of species known has
increased from $40 in 1880 to
1900, about 1900 of the number
now on record being living
species.
The regular markings often
seen on sand hills and beaches
have doubtless often excited the
wonder of even casual observers.
In Il study of various wave pine
nomena, detailed to the Royal
Geographical Society, Mr..
Vaughn Cornish has given spec
ial attention to the ripping of
sand by the wind, and he finds
that the shape of such ripples is
always approximately the same
for all wave-lengths from to ll5
inches, and is the same in desert
sand rs in that of the Seashore.
He has succeeded i'll reproducing
them artificially by the action of
"A steady blast upon ordinary
mixed sand. But sand from
which the finer portion had been
separated did not give the phe.
nOmenOn, and thus it appears
that the ripples depend upon the
presence of particles fine enough
to be tossed away 10y the eddy
that forms in the lee of the
larger grains. Sand dunes are
built up by the wind on similar
principles.
An interesting investigation of
the stability Of motion Of bicy-
Gle has been made by Mr.. Il. j.
w. Whipple, Of Trinity College,
Cambridge, England. lie finds
four critical velocities connected
with the stability, these veloci-
ties with a typical machine APP
pearing to be about 1879, 1914,
IA miles per hour, but being not
easily calculated for any given
machine. At greater velocities
than the first, motion is unstable,