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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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Mercury_or_quicksilver
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1992-09-03
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heavy, silver-gray, metallic element, symbol
Hg (from Latin hydrargyrum), atomic number
80, relative atomic mass 200.59. It is a
dense, mobile liquid with a low melting point
(-38.87°C-37.96°F). Its chief source is the
mineral cinnabar, HgS, but it sometimes
occurs in nature as a free metal.
Its alloys with other metals are called
amalgams (a silver-mercury amalgam is used in
dentistry for filling cavities in teeth).
Industrial uses include drugs and chemicals,
mercury-vapor lamps, arc rectifiers,
power-control switches, barometers, and
thermometers.
Mercury is a cumulative poison that can
contaminate the food chain, and cause
intestinal disturbance, kidney and brain
damage, and birth defects in humans. (The
World Health Organization`s `safe` limit for
mercury is 0.5 milligrams of mercury per
kilogram of muscle tissue). The discharge
into the sea by industry of organic mercury
compounds such as dimethylmercury is the
chief cause of mercury poisoning in the
latter half of the 20th century. Between 1953
and 1975, 684 people in the Japanese fishing
village of Minamata were poisoned (115
fatally) by organic mercury wastes that had
been dumped into the bay and had accumulated
in the bodies of fish and shellfish.
The element was known to the ancient Chinese
and Hindus, and is found in Egyptian tombs of
about 1500 BC. It was named by the alchemists
after the fast-moving god, for its fluidity.