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PRECIOUS STONES.
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the
property it had of attracting small bodies to itself when rubbed. From
this property of Amber our word Electricity is derived. The substance
was also known as Succinum and Lyncurium in Pliny's time, and is still
spoken of as Succinite. The electrical charge is negative.
In
origin Amber is the fossilised resin of certain plants ; at the time
when it was viscous flies often became attached to it, and in their
endeavours to escape have sometimes damaged themselves, so that a leg
of a fly may be found enclosed in Amber a little distance from where
the fly is. Apart from these inclusions most varieties of Amber—all but
the "water-clear" in fact—show numerous minute bubbles; the smaller the
bubbles the more numerous they are, and thus the more cloudy the
specimen seems. Such cloudy material may be clarified by gradually
heating the Amber in an oil of nearly the same refractive index, which
is about 1"53. Eape seed oil is usually used; it gradually permeates
all the minute pores and removes the disturbing cause very largely.
In composition Amber is an oxygenated hydrocarbon having the empirical formula C10H16O.
Amber
is chiefly found on the seaboard of the Baltic, where after storms it
is picked up on the shore; it is also dredged for in the sands of the
shallows. It is found, too, along the coasts of Jutland and
Schleswig-Holstein. In the south and east of England, in Western
Russia, in parts of Poland, in Spain and Sicily, Amber is found in
sandy deposits. One piece in the Imperial Museum in Berlin weighs
eighteen pounds.
Amber of inferior quality is used in the manufacture of some varnishes, and small pieces are now hydraulically
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