Silver in History

Neutron absorption Thermal neutron capture cross section 63.8 barns 

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Figure 6.1 illustrating andent time periods may be of help in discussions about silver in history. 

Copper, being easy to mine and refine, has become a very versatile metal over the course of civilization. Early in human history, it was discovered that soft copper could be made harder and stronger when alloyed with other metals. Copper was and still is important to technology and the development of civilizations. Over the past several thousand years, brass has found multiple uses, such as in coins, cooking utensils, and many types of instruments and hardware that are resistant to corrosion. Even today, brass is used to make musical instruments and bathroom, kitchen, and marine hardware. The U.S. one-cent penny was originally made of copper, but today the penny is made of zinc with a coating of copper. Copper is also an alloy metal used as a substitute for some of the silver in several other U.S. coins. 

Stephen Gomez, in his journey down the Atlantic coast from Nova Scotia to Florida in 1525, found copper and silver in the north. In the following year Gonzalo Fernandez de Oviedo y Valdes (1478—1557) mentioned Gomez and his discoveries in his work on the natural history of the New World (108). 

Getz, Faye, Black Death and the Silver Lining Meaning, Continuity, and Revolutionary Change in Histories of Medieval Vhgyie, Journal of the History ofBiolo, 24 (1991), 265-89. 

The history of the iodides dates from the time of J. L. Gay Lussac s discovery 1 of hydriodic acid in 1813. Iodides occur in sea-water, and in the waters of many natural springs and brines. Iodides also occur in varec in the nitre beds of South America and in many natural phosphates. In whatever form iodine occurs in these substances, it is usual to extract this element as iodine, and subsequently to convert this into the iodide—generally potassium iodide. Potassium iodide is used in analytical and photographical work, and medicinally for the treatment of scrofulous, rheumatic, and syphilitic diseases. Sodium iodide is used as a precipitant for gold and silver in the treatment of weak copper ores from Tharsis, etc. 

He looked about with his new eyes and flexed an experimental smile. It was a smile that solidified, hard and cold as ice, when his new eyes fell on the men and prisoners of whom he was taking charge the Russian princess, Dusha the goddess, Aphrodite, and the young fool, Fitz Kreiner. Power, lust and revenge handed to him on a silver platter. Suddenly, Garudin felt like the richest man in history. 

Wislicenus introduced the use of molecular silver in the synthesis of adipic acid from iodopropionic acid, synthesised hydantoin from cyanic acid and glycocoll, glutaric acid (with L. Limpach), and methyl j8-butyl ketone from methylethylacetoacetic ester. He prepared cyclic ketones of dibasic acids by heating the calcium salts, and discovered vinyl ether and vinylacetic acid. The earlier history of acetoacetic ester has been dealt with (see p. 528) two theories of its structure were proposed that of Frankland and Duppa (1865), who represented it as CH3 CO CH2-COOC2H5, and that of Geuther, who discovered the compound (1863), and represented it at first by a type formula (C = 12, O=8) ... 

Despite the powerful overall image with which the Silver Age went down in history, it was also an epoch of rapidly evolving and diverse trends. Its major watershed appeared around the year 1910, which divided the Silver Age into two seemingly disconnected yet related stages Symbolism and post-Symbolism (or avant-garde ). The latter in its turn took a bifurcated path due to the rivalry between the two dominant schools of the Acmeists and the Futurists , which had little in common with each other, but which nevertheless adopted and transformed, each in its own way, the Symbolist heritage. 

Metal compounds, particularly compounds of the heavy metals, have a history of importance as antimicrobial agents. Because of regulations regarding economic poisons in the environment they are no longer widely used in this appHcation. Mercury, lead, cadmium, uranium, and other metals have been imphcated in cases of poisoning that resulted in government response. The metals whose compounds have been of primary interest as antimicrobials are mercury, silver, and copper. 

Lead, because of its history as an air emission, has been fairly mobile and is particularly soluble in acid environments. Silver is used widely in the electronics industry. Intake of silver compounds can result in permanent discoloration of the skin and may result in damage to kidneys, lungs, mucous membranes, and other organs. 

The elements are obtainable in a state of very high purity but some of their physical properties are nonetheless variable because of their dependence on mechanical history. Their colours (Cu reddish, Ag white and Au yellow) and sheen are so characteristic that the names of the metals are used to describe them. Gold can also be obtained in red, blue and violet colloidal forms by the addition of vtirious reducing agents to very dilute aqueous solutions of gold(III) chloride. A remarkably stable example is the Purple of Cassius , obtained by using SnCla as reductant, which not only provides a sensitive test for Au but is also used to colour glass and ceramics. Colloidal silver and copper are also obtainable but are less stable. 

The use of mercury for extracting precious metals by amalgamation has a long history and was extensively used by Spain in the sixteenth century when her fleet carried mercury from Almaden to Mexico and returned with silver. However, environmental concerns have resulted in falling demand and excess production capacity. It is still used in the extraction of gold and in the Castner-Kellner process for manufacturing chlorine and NaOH (p. 72), and a further major use is in the manufacture of batteries. It is also used in street lamps and AC rectifiers, while its small-scale use in thermometers, barometers and gauges of different kinds, are familiar in many laboratories. 

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