Washington standard. [volume] (Olympia, Wash. Territory) 1860-1921, 1879-03-01
that when the certificate was fled
Washington County included La Rue
Countrywide York Tribune.
Another Light Of the Future.

Some interest has been excited by the
clocks with self.luminous dials, which
have been recently offered for sale in
various places. Having examined one
of them, 1 find that it is coated with
sulphide of calcium ("C anton's phos-
phorus," discovered in 1862, attached
by some resinous medium or varnish.
Though the substance is, therefore, in
composition, only the old and familiar
one above mentioned, its present manu-
facturers have found out some method
of wonderfully increasing its efficiency.
One of these clocks, exposed for mo-
ment to direct sunlight, glows so
brightly as to be easily seen in room
which is not darkened. This phospho-
rescence is, moreover, readily excited
by lamp or gas.light, and one Of these
clocks will continue to glow during an
entire night with no other excitement
than that which it gets by the diffused
light in a room during the day. To-
ward morning the glow is faint, but is
still sufficient to show the position of
the clock hands.
The nature of this curious action
called phosphoresence, from certain
resemblance in effect, although it has
no connection with substance known as
phosphorus in chemistry, is probably as
follows: When light falls upon GER
tain bodies, its vibrations cause changes
in the relative positions OF their parti-
cles, somewhat like the changes which
heat vibrations produce in solids when
they cause them to melt for example,
ice melted by the suns rays. Whens
however, these vibrations cease to act,
the changed substance falls back into
its previous condition las when the
melted ice again congeals) but, in 80
doing, emits again vibrations like those
expended in eifecting the former change,
but of lower "tone" or greater wave.
length. Just as water in freezing emits
heat of low "tone," and thus cold COM
pared with our bodies, but nevertheless
heat compared with zero of tempera-
ture. So these phosphorescent bodies
exposed to strong light suffer a change
Which, in reversing itself, causes the
emission of light again, fainter, it is
true. and lower in "pitch y than the
exciting light, but nevertheless very
appreciable as light.
The substances required to make this
compound-i. e., lime and sulphur
are very cheap, and the French sspSGt
Becquercl, who has deliberately investi-
gated this subject, describes methods
of preparing it so that it shall emit
light Of various colors, orange. green,
blue and violet. If further advance
in brillancy and duration should be
made ut all equal to that shown by the
clock dials as compared with all for
mer specimens, it is not improbable
that this may become very important
substance. If we could paint our walls
with such body it would, as it were,
absorb light during the day and then
emit it during the night, and it would
only be necessary to have curtains to
draw over our luminous wallis at night
to shut out their light when necessary,
Just as we now draw curtains over our,
windows in the day time. In the face
of such an arrangement as this, even
Mr.. Edison's new electric burner ~
would be costly and unnecessary. BY
painting the outside of houses with the
same material all need OF street lamps
would be avoided.
! 1t is true that "some practical diff
culties remain to be overcome" but
what are those in these days of invent
i've power? Should one of our great
inventors take the matter in hand, and
organize stock company, it will, of
course, be merely question of time
and expense in preliminary expert
ments.
Seriously, however, this new form of
phosphorescent sulphide of calcium is
a wonderful substance, which may well
suggest strange possibilities for the flu
ture.-Henry Morton, ia N. Y. Tribune.