The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1905-09-23
New York Herald.

''The world is divided between men
who know and cannot tell and men who
tell and cannot know. The great ex-
positors are dead, Huxley and Tyndall
and all the others, and the great expos
itor Of the future, the interpreter Of
knowledge to the people, has still to be
born.'
These sentences have been quoted
from a book entitled "The New Knowl-
edge,' by a certain Professor Duncan,
which has recently been published by
A. S. Barnes & Co. Despite his modest
disclaimer that he himself falls under
the burden Of these difficult conditions,
the, lay reader into, whose hands this
book may fall is likely to rise up and
call him blessed. 1900,
Radio-Activity Of Matter.
Radio-activity, that new and start
Pg R5sRS5sX of #sasF III "R Mss d shs
covered by Henri Becquerel. But no
scientific discovery comes into the world
parentless of previous conception. Not
to delve, too deeply into the genealogy
Of this, discovery, let us say that its
immediate progenitor was the X-ray. !;
"From the day. says Becquerel,
son which I first had knowledge Of the
discovery Of Professor Roentgen there
came to me, too, the idea of seeing
whether the property Of emitting very
bound up With phosphorescense" Bee
querel uses the qualifying term "too -
because other scientists had started
upon the same line of investigation.
The Importance Of his work and the
luck Of it was that he experimental
with different substances. Out of all
| the substances tried there was one, ura-
mum, that had waited long for this one
precious day. 1t is impossible now to
| say M. Becquerel's experiments proved
that uranium and it's compounds spon.
| taneously emit rays which are able to
traverse Opaque bodies and affect photo,
graphic plates. -.
| Now, uranium is an element ex.
tracted from a compound named pitch.
blende. Professor Pierre Curie of
Paris, and his wife happened to OBJ
serve that pitchble1nde in the rough
uranium extracted from it.
Nature never insults us by caprice
Consequently we find the Curies say
ing: HIt becomes, then, very probable
that if pitchblende has so strong ar
activity it is because the mineral con
tains in small quantities a substance
wonderfully radioactive, different
from Iron URANIUM N or any other elemen'
Experiments justified the shrewdnes.
of this guess. They ended in the dis
covery Of three new elements will
transcendent ray emitting powers-ra
dium, polonium and actinium.
Radium, with it's radio active powe
130, 900 times greater than uranium
placed in the hands of Investigators
mighty engine of research. whose pos
cII>
+, Yet in it's free state it has neve
beer. seen by human eye nor touche,
by human hand It has neve
been isolated, and has bee
studied only in combination wit
other elements chiefly in TIL
form of chloride or bromide. TIL
amount Of radium in pitchblende j
less than one ten-millionth per CEN
It is relatively rarer than gold in Sc
even rarer. The difficulties Of extrat
: tion are immense. A ton of pitchblend
will yield only barely the hundredt
part of gram Of radium Now, to
Of pitchblende is worth 800. Their,
!, fore a gram of radium would cost i
material and labor good deal NOR
than $4,000.
Three Types of Rays.
Radium gives off three distinct type
/ of rays, named respectively alph
f beta and gamma. The alpha rays co
: respond to the rions Or tiny part
t cles laden with positive electrifcatio
! which fly off from gas flames and re
) hot metals that they do not r
! quire high temperature or other e.
Q ceptional conditions. On the contra1
/ they fly off from the substance radiul
l in its normal state. Like IONS eac
!, particle has mass about twice IL
t mass of the hydrogen atom. Like ion
: also, the alpha rays have velocity
10000 miles a second.
It is a property of radium to eau
n certain substances in its neighborhot
t to phosphoresce or light up with a g1o,
= Zinc sulphide is such substance, a
! swering to the bombardment of Il
!, alpha rays alone. Sir William Crook
d has devised an instrument, called spi
' thariscope, which shows beautifully Il
bombardment Of the alpha rays. It co
: sists of small fragment of radiu
8 placed behind zinc sulphide scree
3 which is viewed in the dark thru a tul
containing = magnifying eyepiece.
+ The beta rays are the most spectac
j. lar They consist of negatively charge
4-,1-~