The Wheeling daily intelligencer. [volume] (Wheeling, W. Va.) 1865-1903, 1878-12-16
mIDEscExreLAsS.


What Causes It's Peculiar Character and
How II ID Made.
From the Croetsry and Glall Joarnal !,
Much OF the old glass brought TO light
from the buried cities OF Pompei and Her
culaneum, from Roman tombs, and more
recently from the treasures Of the Cypri-
ote cities or temples, possesses the curious
property oti.idescence, by means Of which
Il reflects light with all the eolors Of the
rainbow. There has been some dispute as
to whether this glass was iridescentwhe
made o. whether it acquired this quality
subsequently by some natural agency.
The more reasonable conclusion, and the
one adopted by Mr.. Peligot, the celebrate
ed French chemist Is that the glass, orig
inally plain, became iridescent from long
exposure 10 the action Of air and moisture
at high temperature, these conditions be-
ing admirably fulfilled In the old Roman
tombs, where most Of this glass Is found!
All glass has q tendency TO become ir-
descent, under certain conditions, but In
some kinds this tendency Is more strongly
marked than in others. In glass for oph-
cal instruments tendency 70 become IN
descent Is q serious fault, and different
kinds OF glass are composed TO form aper-
fectly coloriess lens. Modern chemists and
glassmakers have long been trying to dis
cover the art Of making glass irideseent by
some more speedy means. than that Of bury
ing Il in 8 damp soil for the benefit Of a
thankless posterity. With all the progress
made in kindred branches OF the AT, moth
ing OF note was done In this direction IN
'tiltwo French chemists quite recently sue |
ceeded in aItifciRlly producing this rides |
cence.f The process they make use OF Is 1
said TO consist essentially in submitting |
the glass under q considerable pressure |
and at an elevated temperature 70 the ae-
ton Of water containing fifteen percentum
Of hydrochloric acid Only certain kinds
OF glass are suitable for this operation. |
The action OF this acid Is thought TO be an !
alogous 70 that Of the elements upon the |
older glass. In dissolving the alkaline sill
Gates, and leaving the surface OF the glass
finely ridsed or corrugated and thus capa-
bic OF retracting the light with prismatic
or rainbow coiors, like those OF mother Of
pearl. eaeas Il
The modern glass stands any amount OF
TuODluS Ut Cle4Aulh6 hAAVuA 3oaAa q W
curious property, but 1.-THE exposed sur
face be cut or ground off the irideseent et-
feet is instantly lost, showing that Its cause
il merely superficial, and not structural;a rs
is the case with mother OF pearl. I
The Bohemian glass, so Tar, seems to be
the fayorite for embellishing with the new
iridescence. bohemian glass will resist
much greater heat than any other kind,
and 1t Is made In graceful shapes, and Is
clear and transparent At present the
leading Bohemian factory Is producing
good deal Of this iridescent glassware,
principally for the European market, as
the American public Is hardly, as yet, 90.
quainted with this novel and beautiful
glassware. l
One Of the greatest charms OF this new
glass is its infinite variety and freshness.
10 two pieces are alike In color, and no
piece remains the same when placed in O
new position or regarded from different
point Of REV. AL show greater or small
or range Of the spectrum, curved or bent,
according to the shape OF the glass; but
while some pieces fash with red and yell
low, Others are tender, with . silvery blue
or rich gold gray, and still others exhibit
all the colors OF the rainbow. I