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Gold Parting
Gold parting is the separating of gold from silver (and other metallic impurities). Gold and silver are often extracted from the same ores and are chemically similar and therefore difficult to separate. The alloy of gold and silver is called electrum. Contemporary technology Two technologies are dominant. They both start with relatively pure gold. *The Miller process affords gold up to 99.5% purity. The process involves blowing a stream of chlorine through molten gold. Impurities in the gold form chlorides, which form a slag that floats on the molten gold. *Invented by Emil Wohlwill in 1874, the Wohlwill process produces the highest purity gold (99.999%). It is an electrolytic process using pure gold for the cathode (or titanium as a starter cathode) and chloroauric acid (gold chloride-hydrochloric acid) as the electrolyte; this is made by dissolving gold with chlorine gas in the presence of hydrochloric acid. Gold is dissolved at the anode, and pure gold, traveling through th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental ( native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthashastra
The ''Arthashastra'' ( sa, अर्थशास्त्रम्, ) is an Ancient Indian Sanskrit treatise on statecraft, political science, economic policy and military strategy. Kautilya, also identified as Vishnugupta and Chanakya, is traditionally credited as the author of the text.: "References to the work in other Sanskrit literature attribute it variously to , and . The same individual is meant in each case. The '' Pańcatantra'' explicitly identifies Chanakya with ." The latter was a scholar at Takshashila, the teacher and guardian of Emperor Chandragupta Maurya. Some scholars believe them to be the same person, while a few have questioned this identification.; : "while in his character as author of an ''arthaśāstra'' he is generally referred to by his '' gotra'' name, ;": "T. Burrow... has now shown that Cāṇakya is also a ''gotra'' name, which in conjunction with other evidence makes it clear that we are dealing with distinct persons, the minister Cāṇaky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavian Dynasty
The Flavian dynasty ruled the Roman Empire between AD 69 and 96, encompassing the reigns of Vespasian (69–79), and his two sons Titus (79–81) and Domitian (81–96). The Flavians rose to power during the civil war of 69, known as the Year of the Four Emperors. After Galba and Otho died in quick succession, Vitellius became emperor in mid 69. His claim to the throne was quickly challenged by Roman legion, legions stationed in the Eastern provinces, who declared their commander Vespasian emperor in his place. The Second Battle of Bedriacum tilted the balance decisively in favour of the Flavian forces, who entered Rome on 20 December. The following day, the Roman Senate officially declared Vespasian emperor of the Roman Empire, thus commencing the Flavian dynasty. Although the dynasty proved to be short-lived, several significant historic, economic and military events took place during their reign. The reign of Titus was struck by multiple natural disasters, the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winchester
Winchester is a City status in the United Kingdom, cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government Districts of England, district, at the western end of the South Downs National Park, on the River Itchen, Hampshire, River Itchen. It is south-west of London and from Southampton, its nearest city. At the 2011 census, Winchester had a population of 45,184. The wider City of Winchester district, which includes towns such as New Alresford, Alresford and Bishop's Waltham, has a population of 116,595. Winchester is the county town of Hampshire and contains the head offices of Hampshire County Council. Winchester developed from the Roman Britain, Roman town of Venta Belgarum, which in turn developed from an Iron Age oppidum. Winchester was one of the most important cities in England until the Norman conquest of England, Norman conquest in the eleventh century. It has since become one of the most expensive and afflue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
York
York is a cathedral city with Roman origins, sited at the confluence of the rivers Ouse and Foss in North Yorkshire, England. It is the historic county town of Yorkshire. The city has many historic buildings and other structures, such as a minster, castle, and city walls. It is the largest settlement and the administrative centre of the wider City of York district. The city was founded under the name of Eboracum in 71 AD. It then became the capital of the Roman province of Britannia Inferior, and later of the kingdoms of Deira, Northumbria, and Scandinavian York. In the Middle Ages, it became the northern England ecclesiastical province's centre, and grew as a wool-trading centre. In the 19th century, it became a major railway network hub and confectionery manufacturing centre. During the Second World War, part of the Baedeker Blitz bombed the city; it was less affected by the war than other northern cities, with several historic buildings being gutted and restore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lincoln, Lincolnshire
Lincoln () is a cathedral city, a non-metropolitan district, and the county town of Lincolnshire, England. In the 2021 Census, the Lincoln district had a population of 103,813. The 2011 census gave the urban area of Lincoln, including North Hykeham and Waddington, a population of 115,000. Roman ''Lindum Colonia'' developed from an Iron Age settlement on the River Witham. Landmarks include Lincoln Cathedral (English Gothic architecture; for over 200 years the world's tallest building) and the 11th-century Norman Lincoln Castle. The city hosts the University of Lincoln, Bishop Grosseteste University, Lincoln City FC and Lincoln United FC. Lincoln is the largest settlement in Lincolnshire, with the towns of Grimsby second largest and Scunthorpe third. History Earliest history: ''Lincoln'' The earliest origins of Lincoln can be traced to remains of an Iron Age settlement of round wooden dwellings, discovered by archaeologists in 1972, which have been dated to the first cen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a major settlement for two millennia. The City of London, its ancient core and financial centre, was founded by the Romans as '' Londinium'' and retains its medieval boundaries.See also: Independent city § National capitals The City of Westminster, to the west of the City of London, has for centuries hosted the national government and parliament. Since the 19th century, the name "London" has also referred to the metropolis around this core, historically split between the counties of Middlesex, Essex, Surrey, Kent, and Hertfordshire, which largely comprises Greater London, governed by the Greater London Authority.The Greater London Authority consists of the Mayor of London and the London Assembly. The London Mayor is distinguished fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naturalis Historia
The ''Natural History'' ( la, Naturalis historia) is a work by Pliny the Elder. The largest single work to have survived from the Roman Empire to the modern day, the ''Natural History'' compiles information gleaned from other ancient authors. Despite the work's title, its subject area is not limited to what is today understood by natural history; Pliny himself defines his scope as "the natural world, or life". It is encyclopedic in scope, but its structure is not like that of a modern encyclopedia. It is the only work by Pliny to have survived, and the last that he published. He published the first 10 books in AD 77, but had not made a final revision of the remainder at the time of his death during the AD 79 eruption of Vesuvius. The rest was published posthumously by Pliny's nephew, Pliny the Younger. The work is divided into 37 books, organised into 10 volumes. These cover topics including astronomy, mathematics, geography, ethnography, anthropology, human physiolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliny The Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ''Naturalis Historia'' (''Natural History''), which became an editorial model for encyclopedias. He spent most of his spare time studying, writing, and investigating natural and geographic phenomena in the field. His nephew, Pliny the Younger, wrote of him in a letter to the historian Tacitus: Among Pliny's greatest works was the twenty-volume work ''Bella Germaniae'' ("The History of the German Wars"), which is no longer extant. ''Bella Germaniae'', which began where Aufidius Bassus' ''Libri Belli Germanici'' ("The War with the Germans") left off, was used as a source by other prominent Roman historians, including Plutarch, Tacitus and Suetonius. Tacitus—who many scholars agree had never travelled in Germania—used ''Bella Germani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agatharchides Of Cnidus
Agatharchides or Agatharchus ( grc-gre, Ἀγαθαρχίδης or , ''Agatharchos'') of Cnidus was a Greek historian and geographer (flourished 2nd century BC). Life Agatharchides is believed to have been born at Cnidus, hence his appellation. As Stanley M. Burstein notes, the "evidence for Agatharchides' life is meagre." Photius describes him as a ''threptos'', a kind of assistant of servile origin, to Cinnaeus and states that he was later a secretary to Heraclides Lembus. Cinnaeus served as a counselor to Ptolemy VI; Heraclides is best known for negotiating the treaty that ended Antiochus IV's invasion of Egypt in 169 BC. Agatharchides furnishes few clues about his own life. At the conclusion of his ''On the Erythraean Sea'', he apologizes for being unable to complete his work "since our age is unable to similarly bear the toil" and "as a result of the disturbances in Egypt" he could no longer access the official records (a fragment cited by Photius in his ''Bibliotheca'' Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diodorus Siculus
Diodorus Siculus, or Diodorus of Sicily ( grc-gre, Διόδωρος ; 1st century BC), was an ancient Greek historian. He is known for writing the monumental universal history ''Bibliotheca historica'', in forty books, fifteen of which survive intact, between 60 and 30 BC. The history is arranged in three parts. The first covers mythic history up to the destruction of Troy, arranged geographically, describing regions around the world from Egypt, India and Arabia to Europe. The second covers the time from the Trojan War to the death of Alexander the Great. The third covers the period to about 60 BC. ''Bibliotheca'', meaning 'library', acknowledges that he was drawing on the work of many other authors. Life According to his own work, he was born in Agyrium in Sicily (now called Agira). With one exception, antiquity affords no further information about his life and doings beyond his written works. Only Jerome, in his ''Chronicon'' under the "year of Abraham 1968" (49 BC), w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
