The sun. [volume] (New York [N.Y.]) 1833-1916, 1902-02-09
houadsr around esn.,.rlysu until We led him

than the most energetic OF the active salts.
And you must not be disappointed II you
are not able to read a newspaper withit.
lam here striving to establish a scientific
principle; the industrial development OF 1t
Re- quito another matter. But I begin 70 see
the glow now; do you not see tt?'
The writer did SEQ Il. 1t gradually grew
from an indistinct speek In the blackness In
front until II became a luminous patch the
size OF a dollar. and IL frightened with
the minutes.
To make sure Of his eyes he passed his
hand before them, blottlns out the light
entirely. but when he removed his hand
there It shone brighter than ever. Again
while he was admiring 1t II suddenly dis
appeared. apparently OF It's own accord.
"why. 1t has gone he cried.
. Prof. Hallock laughed.
sYes,'. he said, II have removed the
yellow screen. You see how quickly the
light goes out. OF course. the rays are
there Just the same. but invisible TO us
when not combined with the barium-
cyanide.
Il will replace The screen. There, you
see how. quickly they have turned into
visible light. There is In that box only
two-tenths Of a gram OF active material.
II We had enough 80 that II could be spread
out over. say, a square foot OF space We
would get q rare efulgence.'
well. why not do that for the sake OF
experiment.
For the sake of experiment. he re-
piled. I'VE have don't enough, for we have
established our principles; and, besides,
the present market price OF that material
Is IS a gram. That does not, however, pre-
clude the possibility Of a practical lighting
system being developed from these rays.
And I an Of the opinion that something
practical may be made out Of this general
subject Of phosphorescsnce OF elf-luminos-
ity Of objects. Not only have we discovered
that nest natural objects have the capacity
for storing sunlight, but here is the apparent
capacity for creating light itself possessed
by many substances which heretofore
were supposed to be inert. ''
There lie room at least for reflection when,
as Becquerel points out. a quiet, peaceful
bit Of white salt is capable Of shooting of
rays with a velocity Of over OF 500 miles a
second. There is most urgent need for
discovering the source Of this energy in
view OF its utilization by mankind.
Even In it's present condition. enough
Is known Of the subject OF phosphorescence
to admit Of a little experimentation. l
believe that the owners Of Office buildings
might help out the twilight materially by
the judicious use Of certain luminous paints.
For instance. the walls and ceilings Of
Offices could be covered with these paints
and made to emit light enough TO last with
the twilight on winter evenings until the
close Of Office hours And If the Railways
OF houses and public buildings were to
be coated in like nne n could get
about them at night without the aid OF
more artificial light.
1T is possible that the discovery Of the
source of the energy Of Becquerel ray
might lead us 10 the cause Of animal and
vegetable phosphorescence. This has been
a subject Of investigation during all ages
and especially during the last century,
but Il cannot be said TO ave been solved. -
yet some Of the manifestations are
truly wonderful. There are over 800 kinds
Of luminous beetles In the world and they
form only a small proportion Of the lower
animals which carry their own light.
you have yourself perhaps heard won-
derful stories Of the light-smitting capacity
Of some tropical insects and of certain
deep sea animals. Lord George Campbell
told Of a huge pyrosor,a trawled up from
2.200 fathoms during the voyage of the
Challenger.
1T emitted a great quantity Of light
when irritated. It was a large s~ac-shaped
animal and as II lay in the tub at night the
men wrote their names in full length on
it's back. the nance standing out brilliantly
in letters OF light
There are other tales quite as wonder
full. but the theories accounting for these
lights are really too numerous 10 be told
al a sitting.
But in the efforts Of Becquerel and OF
Nine. Curie we have something tangible
concluded Prof. Haliock. leading the way
out into the laboratory. w AVE some
thing TO go upon. To be- sure We do not
know exactly what il is we have. 1t may
be the energy Of the sur stored without
our present know ledge, although that IA
hardly likely; il may be some properly 81
the ether. il may be, as Nine. Curie sug-
gested. the result Of a transcendcntal raaia-
ton more penetrating than A-ray and per-
valing all space, although Prof. Geitel
found that il such IL the case the radiations
easily penetrate hundred of va rds Of rock,
for radium was still active AZ the bottom
Of the deepest mine In which he was able
10 descend.
AT least it Is the newest force with which
we nave 10 deal. You have seen how il
can he turned into light and when you
think that in spite OF its speed Of OF 500
miles a second the waste from a half inch
Of surface IL ou!v a milligram in a thou
sand million years YOU must admitthat the
rNnaatlilai aa for tho AtshSt apRa n ra rraat y