must
be taken not to overheat it by friction, as it will then be liable to
crack. Amber has occasionally been cut into cameos, busts, images, &c.
Impure
amber pieces may be much improved by wrapping them in paper and
allowing them to digest for forty hours in hot ashes, in a pot filled
with sand ; or by boiling them with gradually increased heat in linseed
oil. Amber may also be colored red, blue, and violet, and dissolved in
absolute alcohol; it may be cast into different ornaments. Broken amber
may be mended by a cement of linseed oil, gum mastic, and litharge; or
by moistening the ends of both pieces with potash, warming the same,
and pressing the parts together.
The
price of amber was, in former times, much higher than at present, but
size, color, and transparency always govern the same. A pure exquisite
specimen of one pound is sold for forty dollars; but most good
specimens are sent to Armenia, the East, and Turkey, to which places
manufactured amber goods to the amount of fifty to sixty thousand
dollars are annually exported from one manufactory at Stolpe, in East
Prussia.
Amber
is often adulterated in various ways, and more especially with giim
copal, which is palmed upon the ignorant for amber, and which does
actually resemble it in many respects: for both are of the same color;
both become negatively electric by friction; both have nearly the same
specific gravity; and both give a pleasant odor in burning; hence when
wrought as jewelry or ornaments, it is not easy to distinguish the one
from the other. One mode of detection was pointed out by the Abbe
Hatty: "If," says he, "a fragment of amber be attached to the point of
a knife and inflamed, it will burn with some noise and a kind of
ebullition, but without liquifying so as to flow, and if it should fall
on any flat surface it rebounds a
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