The sun. [volume] (New York [N.Y.]) 1833-1916, 1902-02-09
GIVES LIGHT WITHOUT HEAT.
PRoF. BALLOCKs EXPERIMENTS
WITH BECQUEREL RAYS.
a way Psund 10 Make Luminous me Myr
terieus Radiant Energy OF certain
substances -Pesstbiiities OF the DIE
cover Things That store Lgnt'

ter,ous Radisnt Energy OF Certain
ACKNOWLEDGEMENTS OF the DIE
cover Things That store Light
Prof. william Hailock OF Columbia uni
vrrnlty has discovered a new kind OF light
which IA without heat. His discovery Ia
The result Of an experiment made with
certain chemical substances which have
hing been known to radiste q mysterious
Energy, the source Of which scientific men
have not sucoceded In tracing.
This form of energy, known under the
usue OF Becquerel rays after the Fench
scientist who discovered It, has always
manifested its presence In much the same
manner AZ ordinary light, except In the
ono important feature OF not being visible.
For instance. photographs could be made
with tire rays, II sensitive plates were LETT
exposed to their influence In dark rooms.
but no one had been able TO see the rays.
Prof. Hallook hit upon q plan for render
ing them visible and as thcy emanate from
Thousands Of substances. the discovery
h important. Again. while the expert
ment was strictly a laboratory test and
was therefore conducted on q small scale,
the procedure bas been established and, a.
Prof. Hallock says. It only remains for the
industrial investigators TO place the dis
eovery on a commercial basis.
What follows was obtained from Prof.
Hallock In his laboratory while the expert
mspf was being made.
In the first place. said Prof. Hallock.
cit must DO conceded that the word dark
nee 10 only q relative term. There are
very fsw places In the world that are abeo-
htsly dark In the true sense Of the word.
The number of substances which are
capable Of storing sunlight all day and
then emitting 1t at night is very great.
lt,may be that all substances are capable
Of doing IL to a greater or less extent.
During the last fve years the investiga-
ton Of the energy Of such substances has
been very extended. Prof. McKissick OF
Auburn. Ala, made experiments with
many common substances such as sugar.
sfucose and chalk. and was able to make
photographs with the energy that ema-
mated from them after they had been ex-
posed to the sun all day. Prof. McKissick
and bis assistants also found that many
strictly chemical substances Possessed this
power Of storing energy
French scientists gave the sub ject
special attention and Becquerel achieved
fame In this line. He discovered that
uranium salts do not need sunlight from
which to draw energy, but are all the time
giving of radiations. which are X-ray In
quality in that they will pass through opaque
bodies and affect Photographic plates or
the other side.
-McKissick placed some coins and keys
on a plate holder containing a Photographic
plate. On these be placed a piece Of wood
~ inches thick.
'0n the wood he placed some common
brown sugar which had been allowed to
absorb sunlight and he covered all with a
black cloth and left them In q dark room
for some hours.
when examined 1t was found that the
energy from the sugar had passed through
the wood and the cover OF the plate holder
and had photographed the metal objects
on the sensitive place.
-Becquerel discovered that uranium
salts were capable Of performing quite
as wonderful feats but tha their energy
seemed to be an initial energy. At least
II was not due to stored sunlight.
then came Nine. Curie. a woman
scientist working in Paris. who discov-
cred the radio-activity Of thortum and
afterward Of pitchblende. Working with
her husband she succeeded in extracting
from p~itchblende o substance named polon-
ium which proved to be at least 100, 900
times more radioactive than uranium.
'0ut OF pitchblende still other substances
were obtained. such as radium and actinium.
80, far no one has been able to discover
the cause Of these rays.
although invisible they have mani
tested their presence very positively In other
ways. They will affect Photographic
plates In the dark. Radium rays will
turn ordinary white giass To a brown or a
violet tint and like X-rays have caused
Inflammation Of the human skin.
Lord Kelvin has shown that some Of
these rays are capable not only OF con-
Quoting an electric current, but that they
arc capable Of generating a current. He
connected q plate Of copper and a plate
Of sine by means OF a wire and then ex-
posed the two plates 10 uranium rays.
The moment this was lone an electric
current began to fow along the wire.
Prof. Pegram. quoting %Becquerel. says
the velocity Of the rays Is about half that
OF ordinary light. but that the waste is so
ANAL that the loss from a square cent?
metre of surface would be something like a
milligram In a thousand million years.
Heat or cold, high or low pressure,
does not Affect them. So that taking them
ell in all they constitute the most wonderful
physical phenomena within our observa-
ton at the present time.
-Now you know that X-rays we're long
invisible until tungstate OF calcium was
used In the Horoscope To make them visible.
II occurred TO me hat some similar sub
stance might be combined with these pro-
ducts Of pitchblendc TO make them visible.
After some consideration / fixed upon
Interchangeable. | tried Il with
the salts. The experiment was a success.
! was able 70 see tho light. But come with
me to the dark room and zee for yourself
He picked up a shallow paper box. the
size OF q watch crystal. containing e small
quantity Of white powder. Near Il lay
whn; looked like a piece Of greenish-yeliow
pastcboard.
He carried these into the dark room and
laid them on the table.
The room was painted black ard every
ciink and crovice had been stopped up 10
prevent the slightest ray Of light from