West Virginia argus. [volume] (Kingwood, W. Va.) 1877-1946, 1879-11-22
Iridcscent GIas-.

1t is not genera " known, that the beau
tiful vases and other forms of irdescent
glass, which have recently begun TO adorn
the windows OF our chnaware dealers, mark
the revival Of one OF the lost arts OF old Ro-
man days. Most Of the old glass brought
TO light from the buried cities Of Pompeii
and llerCulancum, from Roman tombs and
more recently from the treasures of the
CypriOte cities or temples, possesses this
curious property Of iridcscence, by means
OF which it reflects light with all the colors
Of the rainbow. There has been some dis
pute as to whether this glass was ridcscelt
when made, or whether it acquired this
quality subsequently by some natural
agency. The more reasonable conclusion,
and the one adapted by Mr.. Peligot, the
celebrated French chemist, is that the glass
originally plain, became iridcscent from
long exposure TO the action of the air and
moisture at high temperature, these CON
ditlons being admirably fulfilled in the old
Roman tOmbs where most OF the glass ia
found. All glass has tendency to be
come iridescent under certain conditions
but in some kinds this tendency is more
strongly marked than in others In glass
for optical Instruments a tendency ID be-
come iridcscent is a serious fault and differ
ent kinds Of glass are combined TO form
perfect colorless lens. Modern chemists
and glassmakers have long been trying to
discover the art Of making glass iridesccnt
by some more speedy means than that Of
burying ii in a damp soil for the benefit Of
thankess posterity. With all the pro
grcss made in kindred branches Of the art,
nothing Of note was done in this direction
until two French chemists quite recently
succeeded in artihcially producing this
| iridescence. The process they make use
OF is said TO consist essentially in submitting
the glass, under a considerable pressure, and
at an elevated temperature, 10 the action Of
water containing fifteen per cent. Of hydro
chlonc acid. Only certain kinds OF glass
are suitable for this operation. The action
OF this acid is thought TO be analogous 20
that Of the elements upon the older glass in
dissolving the alkaline silicates and leaving
the surface Of the glass finely ridged or cor
ugatcd and thus capable Of refracting the
| lights with prismatic OF rainbow cOlOrs, like
those Of mOthcr-Oi-pearl. The modern glass
stands any amount Of rubbing or cleaning
! without losing its curious property but, il
/ the exposed surface be cut or ground Of.
the iridesccnt effect is Instantly lost, show
/ ing that its cause ~ merely superficial and
/ not structural, as is the case with mother
| Oi-pcarl. The Bohemian glass, 80 far, seems
/ TO be the favOrite for embelishing with the
| new iridescencc. Bohemian glass will re-
| sist a much greater heat than any other
/ kind and is made in graceful shapes, and
/ is clear and transparent. At present the
| leading Bohemian factory is producing q
| good deal of this iridcscent glassware, prin-
| cipally for the European market as the
| American public is hardly yet acquainted
/ with this novel and beautiful glassware.
\ One Of the greatest charms OF this new glass
\ is ils infinite variety and freshness No
/ two pieces are alike in color, and no piece
/ remains the same when placed in new
/ position or regarded from n different point
Of view Al show a greater or smaller
\ range Of the spectrum, curve or bent, re
/ cording Co the shape Of the glass but while
/ some pieces flash with red and yellow, 9th
/ CTS arc tender, with a silvery blue OF rich
| gold gray, and still others exhibit OH the
| cOlOrs oi the rainbow.