The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1894-11-13
The aiu Eagle TnesdaY oruue Houmber Is, 1884

face Is covered with strange network
of sculpture, indicative Of molecular
changes
But probably the most interesting
thing about the corundum crystal is
the fact that it is nearly always found
to have enclosed and surrounded some
foreign body or other. which lies i'm
prisoned in it. Stranger still is the
fact that these included foreign bodies
lie generally disposed of in planes
meeting each other at an angle of sixty
degrees, the result being TO produce
the phenomenon of asterism, which is
the term given to the white star OF
light which is observable on certain
jewels cut with rounded surface.
Very frequently the imprisoned body
is a minute bubble of gas or drop of
liquid containing sometimes little
crystals of its own.
The microscopic cavities containing
these things are often very numerous.
For long time the nature OF the gas
and fluid in the cavities remained a
mystery. The English philosopher,
Brewster, was induced to investigate
the subject by hearing that a ruby
which an Edinburgh jeweler had
placed in his mouth had exploded
while in that position. with unpleasant
results. Other investigators followed,
and IT has now been made certain that
the fluid is no other than liquid car
bonic acid gas, reduced to that con-
dition by being under great pressure.
The color of the ruby is another of
its mysteries. and one upon which Prof.
Judd was only able to touch upon
slightly in his lecture. The color is
distributed most irregularly, and some
corundum crystals show in patches the
tints of the ruby, the sapphire, and the
emerald all mixed together. These
colors are, of course, due to the special
way in which the structure OF the crys-
tai deals with the light passing through
It, the ruby absorbing all the rays ex-
cept those which emerge to give it its
characteristic color.
How greatly these colors depend on
molecular and chemical changes going
on in the crystal is obvious from the
strange way some gems behave under
light and heat. Prof. Maskelyne men,
tions diamond which, when taken out
of the warm pocket and allowed to cool
on the table, turned a beautiful red.
Prof. Judd startled his audience by de.
claring that the green glass panes used
in the Conservatives at Kew gradually
changed through various shades of yell
low to a distinct purplish hue under
the prolonged action of light.
Rubies change their color in cur
ious way under the action of heat.
Blush rubies turn perfectly green, and
on cooling regain their original tint.
The blue sapphire turns white, and the
yellow corundum crystal becomes
green. Then there is the strange prop
erty of ''pleochroism" in the ruby fam
lily and its kindred; they exhibit differ
ent tints, according to the size of the
crystal you are examining. Some
powdered oxide of alumni
NUN was placed in a vacuum tube and
subjected to the electrical discharge
from high-tension coil.
1t was shown that the white powder
glowed with the red brilliant red of the
ruby, and that the glow continued
after the discharge ceased-a fact
which seems a curious conformation of
the ancient idea that rubies would
glow for time in the dark The same
experiment was repeated with a variety
of corundum stones, artificial rubies,
ETC., to show the greater or less degree
of ruby glow exhibited by each,