Evening star. [volume] (Washington, D.C.) 1854-1972, 1909-12-26

EVERYONE IS familiar with the NernSt
Il lamp and most of US have at one time or
other examined the little glover" or part
that gives out the intense light. This IS small
rod made of the oxids of some rare chemical
elements, hardly as thick as the lead in pen
Gil and an inch long or less. When heated by
electric current to its normal temperature OF
nearly four thousand degrees Fahrenheit. it
gives the brilliant light to which we accus-
toned.
The curious phenomenon to be described Oc-
ours when small particle of one OF certain
metals IS placed on such glover, which in this
case must be run direct current and at
temperature below the melting point of the
metal. On examination through a magnifving
glass or low power microscope. one IS amazed
to see that instead of living quietly on the
face the particle is showing decided tendency
to move. As the current IS increased, thus
raising the temperature, it actually does begin
to move with an irregular rolling motion toward
one end of the glover.
The appearance 1t presents IS very striking as
it turns slowly end over end, suggesting
miniature trunk rolled on its corners by Invisi-
bic hands. now paving stone being turned
over and over, or perhaps pole, elevated to
vertical position by an unseen gang OF mlnia-
ture workmen, only to be lowered again on the
other side and the process repeated with the
other end up. These and many other SMILES
strike one according to the shape of the par
ticle. for the most irregular pieces will roll
with ease. If the glover is held vertically the
particle will roll up and down it as we'll as when
horizontal and the effect is unchanged
when the glover is turned over. when it will
walk like fly on the under side But
while the particle apparently defes gravitatIon
in this respect there IS one law it always obevs.
and that is to change instantly the direction of
its motion when the direction of the electric
current is reversed. 1t can thus be made to go
up and down or back and forth at will
But the Strangest part IS vet to be seen. As
the glover is made hotter by increasing the
rent the motion of the particle is accelerated,
and this continues until the melting tempera-
ture of the metal is reached Suddenly, then,
and with something akin to puff of smoke, it
disappears, leaving no trace behind but
roughened discoloration on the surface of the
glover showing where the molten metal has
vanished or been absorbed If now, after the
temperature has been lowered again, another
particle of the same metal is rolled up to the
spot. it hesitates and finally stops altogether.
refusing to cross the place No Oriental could
show more respect to the grave of one of his
ancestors than does this inanimate particle of
metal toward the grave" of its predecessor.
But if the glover is very strongly heated after
such particle has been melted into it, the i'm
prisoned metal is driven off. Curious white
forms sometimes seen to grow out of the
spot as the temperature rises-oxids of the
metal, the unsentimental chemist will probably
say; but one cannot escape the feeling that
they are ghosts rising from the grave" of
the departed metal. They dance and culver
in the intense heat and finally disappear. leav-
ing surface over which when cooled some
what another particle will roll freely
While we know quite a little about them, the
exact cause of these actions must remain for
the present one of the minor mysteries of phvsi-
cal science The experiment, however is a
simple one to perform and will repay well the
slight trouble involved A Nernst glover suit
able for with direct current can be readily
procured, and should be used with means for
cutting down the current at will. For some
reason cobalt is by far the best metal to USE
although copper will also show the effect we'll
The particles should be about the size of
small grain Of salt. Through a magnifying