|
Hg
Hg symbol for the element mercury .
...
Read more
|
|
barometer
barometer , instrument for measuring atmospheric pressure. It was invented in 1643 by the Italian scientist Evangelista Torricelli, who used a column of water in a tube 34 ft (10.4 m) long. This inconvenient water column was soon replaced by mercury, which is denser than water and requires a tube ab...
Read more
|
|
|
amalgamation process
amalgamation process , in particular, a method to extract gold and silver from ores. The ore is crushed and treated with mercury , in which the metal dissolves. The amalgam is heated and the mercury evaporates, leaving pure gold or silver. The process has been criticized as an environmental and occ...
Read more
|
|
|
cinnabar
cinnabar , mineral, the sulfide of mercury, HgS. Deep red in color, it is used as a pigment (see vermilion ), but principally it is a source of the metal mercury. It is mined in Spain, Italy, and in the United States in California. The mercury is obtained from it by roasting, the sulfur combining w...
Read more
|
|
|
Mercury
Mercury in Roman religion, god of commerce and messenger of the gods; identified with the Greek Hermes . He was honored at the Mercuralia, a festival held in May and attended primarily by traders and merchants.
...
Read more
|
|
mercury poisoning
mercury poisoning tissue damage resulting from exposure to more than trace amounts of the element mercury or its compounds. Elemental mercury (the silver liquid familiar from thermometers) is the most common occupational source. Exposure typically comes from inhaling mercury vapors. Inorganic sal...
Read more
|
|
|
astronomical unit
astronomical unit (AU), mean distance between the earth and sun; one AU is c.92,960,000 mi (149,604,970 km). The astronomical unit is the principal unit of measurement within the solar system, e.g., Mercury is just over 1/3 AU and Pluto is about 39 AU from the sun.
...
Read more
|
|
|
Martianus Capella
Martianus Capella , fl. 5th cent.?, Latin writer, b. Carthage. His one famous work, The Marriage of Mercury and Philology, also called the Satyricon and Disciplinae, is a long allegory about the liberal arts. Its popularity in medieval schools was universal. The author is also known as Felix C...
Read more
|
|
quadrature
quadrature in astronomy, arrangement of two celestial bodies at right angles to each other as viewed from a reference point. If the reference point is the earth and the sun is one of the bodies, a planet is in quadrature when its elongation is 90°. As viewed from the earth, the half-moon is i...
Read more
|
|
thermometer
thermometer instrument for measuring temperature . Galileo and Sanctorius devised thermometers consisting essentially of a bulb with a tubular projection, the open end of which was immersed in a liquid. Heating or cooling the bulb affected the height of the column of liquid in the tube, on which a...
Read more
|
