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75-512: (Redirected from Third Pandemic ) The Third pandemic may refer to: Third plague pandemic 1855–1960 Third cholera pandemic 1846–1860 The Third Pandemic , a 1996 science fiction novel by Pierre Ouellette See also [ edit ] Pandemic (disambiguation) First pandemic (disambiguation) Second pandemic (disambiguation) Fourth pandemic Fifth pandemic Sixth pandemic Seventh pandemic Topics referred to by

150-573: A Gilman reagent . These can undergo substitution with alkyl halides to form coupling products ; as such, they are important in the field of organic synthesis . Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot–Chodkiewicz coupling and the Sonogashira coupling . Conjugate addition to enones and carbocupration of alkynes can also be achieved with organocopper compounds. Copper(I) forms

225-696: A covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper. At the macroscopic scale, introduction of extended defects to the crystal lattice , such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms. The softness of copper partly explains its high electrical conductivity ( 59.6 × 10   S /m ) and high thermal conductivity, second highest (second only to silver) among pure metals at room temperature. This

300-636: A nickel ) consists of 75% copper and 25% nickel in homogeneous composition. Prior to the introduction of cupronickel, which was widely adopted by countries in the latter half of the 20th century, alloys of copper and silver were also used, with the United States using an alloy of 90% silver and 10% copper until 1965, when circulating silver was removed from all coins with the exception of the half dollar—these were debased to an alloy of 40% silver and 60% copper between 1965 and 1970. The alloy of 90% copper and 10% nickel, remarkable for its resistance to corrosion,

375-407: A pinkish-orange color . Copper is used as a conductor of heat and electricity, as a building material , and as a constituent of various metal alloys , such as sterling silver used in jewelry , cupronickel used to make marine hardware and coins , and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in

450-425: A spin of 3 ⁄ 2 . The other isotopes are radioactive , with the most stable being Cu with a half-life of 61.83 hours. Seven metastable isomers have been characterized; Cu is the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β , whereas those with a mass number below 64 decay by β . Cu , which has

525-399: A blast furnace. A potential source of copper is polymetallic nodules, which have an estimated concentration 1.3%. Like aluminium , copper is recyclable without any loss of quality, both from raw state and from manufactured products. In volume, copper is the third most recycled metal after iron and aluminium. An estimated 80% of all copper ever mined is still in use today. According to

600-459: A blue crystalline penta hydrate , the most familiar copper compound in the laboratory. It is used in a fungicide called the Bordeaux mixture . Polyols , compounds containing more than one alcohol functional group , generally interact with cupric salts. For example, copper salts are used to test for reducing sugars . Specifically, using Benedict's reagent and Fehling's solution the presence of

675-709: A directly usable metallic form ( native metals ). This led to very early human use in several regions, from c.  8000 BC . Thousands of years later, it was the first metal to be smelted from sulfide ores, c.  5000 BC ; the first metal to be cast into a shape in a mold, c.  4000 BC ; and the first metal to be purposely alloyed with another metal, tin , to create bronze , c.  3500 BC . Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite , malachite , and turquoise , and have been used widely and historically as pigments. Copper used in buildings, usually for roofing, oxidizes to form

750-467: A few weeks. Daily water-traffic with the nearby city of Hong Kong rapidly spread the plague. Within two months, after 100,000 deaths, the death rates dropped below epidemic rates, but the disease continued to be endemic in Hong Kong until 1929. The network of global shipping ensured the widespread distribution of the disease over the next few decades. Recorded outbreaks included the following: Each of

825-457: A green patina of compounds called verdigris . Copper is sometimes used in decorative art , both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents , fungicides , and wood preservatives . Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase . In molluscs and crustaceans , copper

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900-495: A half-life of 12.7 hours, decays both ways. Cu and Cu have significant applications. Cu is used in Cu Cu-PTSM as a radioactive tracer for positron emission tomography . Copper is produced in massive stars and is present in the Earth's crust in a proportion of about 50 parts per million (ppm). In nature, copper occurs in

975-683: A layer of brown-black copper oxide which, unlike the rust that forms on iron in moist air, protects the underlying metal from further corrosion ( passivation ). A green layer of verdigris (copper carbonate) can often be seen on old copper structures, such as the roofing of many older buildings and the Statue of Liberty . Copper tarnishes when exposed to some sulfur compounds, with which it reacts to form various copper sulfides . There are 29 isotopes of copper. Cu and Cu are stable, with Cu comprising approximately 69% of naturally occurring copper; both have

1050-532: A natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air. This is due to the low plasma frequency of the metal, which lies in the red part of the visible spectrum, causing it to absorb the higher-frequency green and blue colors. As with other metals, if copper is put in contact with another metal in the presence of an electrolyte , galvanic corrosion will occur. Copper does not react with water, but it does slowly react with atmospheric oxygen to form

1125-506: A person responsible for transporting and burying the plague dead. Researchers working in Asia during the "Third Pandemic" identified plague vectors and the plague bacillus. In 1894, in Hong Kong, Swiss-born French bacteriologist Alexandre Yersin isolated the responsible bacterium ( Yersinia pestis , named for Yersin) and determined the common mode of transmission. His discoveries led in time to modern treatment methods, including insecticides ,

1200-457: A plague vaccine. After three months of persistent work with a limited staff, a form for human trials was ready. On January 10, 1897, Haffkine tested it on himself. After the initial test was reported to the authorities, volunteers at the Byculla jail were used in a control test. All inoculated prisoners survived the epidemics, while seven inmates of the control group died. By the turn of the century,

1275-407: A red-brown precipitate with copper(II) salts. Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry . They are synthesized by treating copper(I) compounds with Grignard reagents , terminal alkynes or organolithium reagents ; in particular, the last reaction described produces

1350-451: A rich variety of compounds, usually with oxidation states +1 and +2, which are often called cuprous and cupric , respectively. Copper compounds promote or catalyse numerous chemical and biological processes. As with other elements, the simplest compounds of copper are binary compounds, i.e. those containing only two elements, the principal examples being oxides, sulfides, and halides . Both cuprous and cupric oxides are known. Among

1425-424: A variety of minerals, including native copper , copper sulfides such as chalcopyrite , bornite , digenite , covellite , and chalcocite , copper sulfosalts such as tetrahedite-tennantite , and enargite , copper carbonates such as azurite and malachite , and as copper(I) or copper(II) oxides such as cuprite and tenorite , respectively. The largest mass of elemental copper discovered weighed 420 tonnes and

1500-436: A variety of weak complexes with alkenes and carbon monoxide , especially in the presence of amine ligands. Copper(III) is most often found in oxides. A simple example is potassium cuprate , KCuO 2 , a blue-black solid. The most extensively studied copper(III) compounds are the cuprate superconductors . Yttrium barium copper oxide (YBa 2 Cu 3 O 7 ) consists of both Cu(II) and Cu(III) centres. Like oxide, fluoride

1575-579: Is a constituent of the blood pigment hemocyanin , replaced by the iron-complexed hemoglobin in fish and other vertebrates . In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. In the Roman era , copper was mined principally on Cyprus , the origin of the name of the metal, from aes cyprium (metal of Cyprus), later corrupted to cuprum (Latin). Coper ( Old English ) and copper were derived from this,

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1650-405: Is a highly basic anion and is known to stabilize metal ions in high oxidation states. Both copper(III) and even copper(IV) fluorides are known, K 3 CuF 6 and Cs 2 CuF 6 , respectively. Some copper proteins form oxo complexes , which, in extensively studied synthetic analog systems, feature copper(III). With tetrapeptides , purple-colored copper(III) complexes are stabilized by

1725-401: Is because the resistivity to electron transport in metals at room temperature originates primarily from scattering of electrons on thermal vibrations of the lattice, which are relatively weak in a soft metal. The maximum possible current density of copper in open air is approximately 3.1 × 10  A/m , above which it begins to heat excessively. Copper is one of a few metallic elements with

1800-545: Is different from Wikidata All article disambiguation pages All disambiguation pages Third plague pandemic The name refers to the third of at least three known major plague pandemics. The first began with the Plague of Justinian , which ravaged the Byzantine Empire and surrounding areas in 541 and 542; the pandemic persisted in successive waves until the middle of the 8th century. The second began with

1875-529: Is melted in a furnace and then reduced and cast into billets and ingots ; lower-purity scrap is refined by electroplating in a bath of sulfuric acid . The environmental cost of copper mining was estimated at 3.7 kg CO2eq per kg of copper in 2019. Codelco, a major producer in Chile, reported that in 2020 the company emitted 2.8t CO2eq per ton (2.8 kg CO2eq per kg) of fine copper. Greenhouse gas emissions primarily arise from electricity consumed by

1950-444: Is one of the most important constituents of silver and karat gold solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys. Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals. The alloy of copper and nickel , called cupronickel , is used in low-denomination coins, often for the outer cladding. The US five-cent coin (currently called

2025-437: Is recovered from mine tailings and heaps. A variety of methods are used including leaching with sulfuric acid, ammonia, ferric chloride. Biological methods are also used. A significant source of copper is from recycling. Recycling is facilitated because copper is usually deployed in its metallic state. In 2001, a typical automobile contained 20–30 kg of copper. Recycling usually begins with some melting process using

2100-411: Is used for various objects exposed to seawater, though it is vulnerable to the sulfides sometimes found in polluted harbors and estuaries. Alloys of copper with aluminium (about 7%) have a golden color and are used in decorations. Shakudō is a Japanese decorative alloy of copper containing a low percentage of gold, typically 4–10%, that can be patinated to a dark blue or black color. Copper forms

2175-590: The Black Death , which killed at least one third of Europe 's population in a series of expanding waves of infection from 1346 to 1353; this pandemic recurred regularly until the 19th century. Casualty patterns indicate that waves of this late-19th-century/early-20th-century pandemic may have come from two different sources. The first was primarily bubonic and was carried around the world through ocean-going trade, through transporting infected persons, rats , and cargoes harboring fleas . The second, more virulent strain,

2250-675: The British Geological Survey , in 2005, Chile was the top producer of copper with at least one-third of the world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage. An alternative source of copper for collection currently being researched are polymetallic nodules , which are located at

2325-588: The Great Lakes may have also been mining copper during this time, making it one of the oldest known examples of copper extraction in the world. There is evidence from prehistoric lead pollution from lakes in Michigan that people in the region began mining copper c.  6000 BC . Evidence suggests that utilitarian copper objects fell increasingly out of use in the Old Copper Complex of North America during

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2400-536: The International Resource Panel 's Metal Stocks in Society report , the global per capita stock of copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita). The process of recycling copper is roughly the same as is used to extract copper but requires fewer steps. High-purity scrap copper

2475-699: The Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), when copper tools were used with stone tools. The term has gradually fallen out of favor because in some parts of the world, the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during

2550-583: The Pearl River delta, including Canton and Hong Kong . Although William McNeil and others believe the plague to have been brought from the interior to the coastal regions by troops returning from battles against the Muslim rebels, Benedict suggested evidence to favor the growing and lucrative opium trade, which began after about 1840. In the city of Canton, beginning in March 1894, the disease killed 80,000 people in

2625-521: The Vinča culture date to 4500 BC. Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC. Egyptian Blue , or cuprorivaite (calcium copper silicate) is a synthetic pigment that contains copper and started being used in ancient Egypt around 3250 BC. The manufacturing process of Egyptian blue was known to the Romans, but by the fourth century AD the pigment fell out of use and

2700-539: The 9th or 10th century AD. Carbon dating has established mining at Alderley Edge in Cheshire , UK, at 2280 to 1890 BC. Ötzi the Iceman , a male dated from 3300 to 3200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest an involvement in copper smelting. Experience with copper has assisted the development of other metals; in particular, copper smelting likely led to

2775-511: The British governments, leading to Indian resentment of quarantine measures. In South Africa, when the plague broke out in Cape Colony , the colonial government forced a large group of Black South Africans to move out of a supposed slum into areas on the outskirts of the city, which historians have argued as a racially-motivated move by White South Africans to segregate Blacks into other parts of

2850-512: The Bronze Age and a shift towards an increased production of ornamental copper objects occurred. Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC. Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use. Bronze artifacts from

2925-508: The League of Nations health organization. From these conventions came the standard Protocols used in dealing with the bubonic plague throughout the early 1900s. These protocols were often old fashioned and were generally summarized as the 3 "I's": Isolation, Incineration, and Inoculation. Isolation is a standard protocol of many modern disease outbreaks, but the usage of incineration was a protocol of disease control used most uniquely for dealing with

3000-535: The Middle East; a copper pendant was found in northern Iraq that dates to 8700 BC. Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper. The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing , smelting , and, finally, lost-wax casting . In southeastern Anatolia , all four of these techniques appear more or less simultaneously at

3075-521: The affected areas is highly acidic, with a pH range of 2.1–4.9, and shows elevated electrical conductivity levels between 280 and 1561 mS/cm. These changes in water chemistry make the environment inhospitable for fish, essentially rendering the water uninhabitable for aquatic life. Numerous copper alloys have been formulated, many with important uses. Brass is an alloy of copper and zinc . Bronze usually refers to copper- tin alloys, but can refer to any alloy of copper such as aluminium bronze . Copper

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3150-445: The areas, as well as Great Britain , France , and other areas of Europe, continued to experience plague outbreaks and casualties until the 1960s, although extremely few of these occurred after 1950. The last significant outbreak of plague associated with the pandemic occurred in Peru and Argentina in 1945. The 1894 Hong Kong plague was a major outbreak of the third global pandemic from

3225-531: The atmosphere; 150 mg/kg in soil; 30 mg/kg in vegetation; 2 μg/L in freshwater and 0.5 μg/L in seawater. Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Sites include Chuquicamata , in Chile, Bingham Canyon Mine , in Utah, United States, and El Chino Mine , in New Mexico, United States. According to

3300-734: The beginning of the Neolithic c.  7500 BC . Copper smelting was independently invented in different places. The earliest evidence of lost-wax casting copper comes from an amulet found in Mehrgarh , Pakistan, and is dated to 4000 BC. Investment casting was invented in 4500–4000 BC in Southeast Asia Smelting was probably discovered in China before 2800 BC, in Central America around 600 AD, and in West Africa about

3375-578: The bubonic plague. Burning was used often to deal with the Plague as it was believed to be the most effective way to eliminate strains of the disease from places inhabited by the infected. But it was also a problematic technique as it led to the creation of many out-of-control fires that devastated communities, the most notable being the great fire in Honolulu which devastated the Chinatown community there. Inoculation

3450-400: The city. In Hong Kong the British enforced many locally unfamiliar medical practices, such as floating plague victims out on boats onto the water and cooling plague victims with ice, which scared many Chinese residents of Hong Kong and led to their migrating back to mainland China, which was then even more badly affected by the plague. Another instance of social harm caused by the response to

3525-527: The company, especially when sourced from fossil fuels, and from engines required for copper extraction and refinement. Companies that mine land often mismanage waste, rendering the area sterile for life. Additionally, nearby rivers and forests are also negatively impacted. The Philippines is an example of a region where land is overexploited by mining companies. Copper mining waste in Valea Şesei, Romania, has significantly altered nearby water properties. The water in

3600-522: The deprotonated amide ligands. Complexes of copper(III) are also found as intermediates in reactions of organocopper compounds, for example in the Kharasch–Sosnovsky reaction . A timeline of copper illustrates how this metal has advanced human civilization for the past 11,000 years. Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in

3675-454: The depths of the Pacific Ocean approximately 3000–6500 meters below sea level. These nodules contain other valuable metals such as cobalt and nickel . Copper has been in use for at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900. As with many natural resources, the total amount of copper on Earth is vast, with around 10 tons in

3750-550: The discovery of iron smelting . Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6500 and 3000 BC. A copper spearpoint found in Wisconsin has been dated to 6500 BC. Copper usage by the indigenous peoples of the Old Copper Complex from the Great Lakes region of North America has been radiometrically dated to as far back as 7500 BC. Indigenous peoples of North America around

3825-555: The early days, Sheung Wan was a Chinese settlement. Houses — in the mountains — had no drainage channels, toilets, or running water. The houses were small and the floors were not paved. Secondly, during the Ching Ming Festival in 1894, many Chinese living in Hong Kong returned to the countryside to tend to family graves, which coincided with the outbreak of the epidemic in Canton and the introduction of bacteria into Hong Kong. Thirdly, in

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3900-545: The fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal aquo complex . Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper(II) hydroxide . A simplified equation is: Aqueous ammonia results in the same precipitate. Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II) : Many other oxyanions form complexes; these include copper(II) acetate , copper(II) nitrate , and copper(II) carbonate . Copper(II) sulfate forms

3975-437: The first four months of 1894, rainfall decreased and soil dried up, accelerating the spread of the plague. The main preventive measures were setting up plague hospitals and deploying medical staff to treat and isolate plague patients; conducting house-to-house search operations, discovering and transferring plague patients, and cleaning and disinfecting infected houses and areas; and setting up designated cemeteries and assigning

4050-511: The flea, blocking it. When the flea next bites a mammal, the consumed blood is regurgitated along with the bacillus into the bloodstream of the bitten animal. Any serious outbreak of plague in humans is preceded by an outbreak in the rodent population. During the outbreak, infected fleas that have lost their normal rodent hosts seek other sources of blood. The British colonial government in India pressed medical researcher Waldemar Haffkine to develop

4125-497: The late 19th century to the early 20th century. The first case, discovered in May 1894, was a hospital clerk who had just returned from Canton . The hardest hit was the mountainous area in Sheung Wan , the most densely-populated area in Hong Kong, characterised by Chinese-style buildings. From May to October 1894, the plague killed more than 6,000 people, leading to the exodus of one third of

4200-511: The later spelling first used around 1530. Copper, silver , and gold are in group 11 of the periodic table; these three metals have one s-orbital electron on top of a filled d- electron shell and are characterized by high ductility , and electrical and thermal conductivity. The filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds . Unlike metals with incomplete d-shells, metallic bonds in copper are lacking

4275-419: The level of <1% Cu. Concentration of the ore is required, which begins with comminution followed by froth flotation . The remaining concentrate is the smelted, which can be described with two simplified equations: Cuprous oxide reacts with cuprous sulfide to convert to blister copper upon heating This roasting gives matte copper, roughly 50% Cu by weight, which is purified by electrolysis. Depending on

4350-472: The modern world. The price of copper is volatile . After a peak in 2022 the price unexpectedly fell. The global market for copper is one of the most commodified and financialized of the commodity markets , and has been so for decades. The great majority of copper ores are sulfides. Common ores are the sulfides chalcopyrite (CuFeS 2 ), bornite (Cu 5 FeS 4 ) and, to a lesser extent, covellite (CuS) and chalcocite (Cu 2 S). These ores occur at

4425-678: The number of inoculees in India alone reached four million. Haffkine was appointed the Director of the Plague Laboratory (now called the Haffkine Institute ) in Bombay. In the early 1900s, despite the increasing knowledge of germ theory and the rapid growth of scientific communities around the prevention of major disease, there was little the international communities could do other than create standard protocols for how to deal with an outbreak of

4500-516: The numerous copper sulfides , important examples include copper(I) sulfide ( Cu 2 S ) and copper monosulfide ( CuS ). Cuprous halides with fluorine , chlorine , bromine , and iodine are known, as are cupric halides with fluorine , chlorine , and bromine . Attempts to prepare copper(II) iodide yield only copper(I) iodide and iodine. Copper forms coordination complexes with ligands . In aqueous solution, copper(II) exists as [Cu(H 2 O) 6 ] . This complex exhibits

4575-428: The ore, sometimes other metals are obtained during the electrolysis including platinum and gold. Aside from sulfides, another family of ores are oxides. Approximately 15% of the world's copper supply derives from these oxides. The beneficiation process for oxides involves extraction with sulfuric acid solutions followed by electrolysis. In parallel with the above method for "concentrated" sulfide and oxide ores, copper

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4650-475: The plague is the "great fire of Honolulu " in 1900, in which much of Chinatown in Honolulu was burned by the Honolulu Board of Health in order to control the plague, rendering over 7,000 Chinese and Japanese residents homeless. In America when the plague reached San Francisco, the medical board of the city implemented a strict quarantine of the entire Chinatown district after discovering only one case of

4725-567: The plague. In 1897 and 1903, two conventions were held known as International Sanitary Conferences; the first in Venice and the second in Paris, to help deal with threat of the new outbreaks of the bubonic plague. From these conventions was formed an international disease convention supervised by the Office International d'Hygiene Publique (OIHP) in Paris which would be one of the major predecessors of

4800-494: The plague; this has led historians to question whether this measure was motivated by racial bias among medical professionals. [REDACTED] Media related to Plague, third pandemic at Wikimedia Commons. Copper Copper is a chemical element ; it has symbol Cu (from Latin cuprum ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity . A freshly exposed surface of pure copper has

4875-463: The population had exploded to over 7 million people. Increasing transportation throughout the region brought people in contact with plague-infected fleas , the primary vector between the yellow-breasted or buff-breasted rat ( Rattus flavipectus ) aka Rattus tanezumi and humans. People brought the fleas and rats back into growing urban areas, where small outbreaks sometimes reached epidemic proportions. The plague spread further and began to appear in

4950-402: The population. In the 30 years starting in 1926 , the plague occurred in Hong Kong almost every year and killed more than 20,000 people. Through maritime traffic, the epidemic spread to the rest of the country after 1894 and eventually spread to British Raj India where about ten million Indians were killed . There were several reasons for the rapid outbreak and spread of the plague. Firstly, in

5025-424: The same term [REDACTED] This disambiguation page lists articles associated with the title Third pandemic . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Third_pandemic&oldid=946095625 " Category : Disambiguation pages Hidden categories: Short description

5100-715: The secret to its manufacturing process became lost. The Romans said the blue pigment was made from copper, silica, lime and natron and was known to them as caeruleum . The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, and 600 BC in Northern Europe. The transition between

5175-459: The spread of the disease throughout the world from Asia to the rest of Europe, to reach Africa and the Americas . A natural reservoir or nidus for plague is in western Yunnan : it is still a health risk. The third pandemic of plague originated in the area after a rapid influx of Han Chinese to exploit the demand for minerals, primarily copper , in the second half of the 19th century. By 1850,

5250-438: The sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide. Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose . Amino acids such as cystine form very stable chelate complexes with copper(II) including in the form of metal-organic biohybrids (MOBs). Many wet-chemical tests for copper ions exist, one involving potassium ferricyanide , which gives

5325-399: The top kilometer of Earth's crust, which is about 5 million years' worth at the current rate of extraction. However, only a tiny fraction of these reserves is economically viable with present-day prices and technologies. Estimates of copper reserves available for mining vary from 25 to 60 years, depending on core assumptions such as the growth rate. Recycling is a major source of copper in

5400-413: The use of antibiotics and eventually plague vaccines . In 1898, French researcher Paul-Louis Simond demonstrated the role of fleas as a vector. The disease is caused by a bacterium usually transmitted by the bite of fleas from an infected host, often a black rat . The bacteria are transferred from the blood of infected rats to flea ( Xenopsylla cheopis ). The bacillus multiplies in the stomach of

5475-515: Was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal , with the largest single crystal ever described measuring 4.4 × 3.2 × 3.2 cm . Copper is the 26th most abundant element in Earth's crust , representing 50 ppm compared with 75 ppm for zinc , and 14 ppm for lead . Typical background concentrations of copper do not exceed 1 ng/m in

5550-464: Was primarily pneumonic in character with a strong person-to-person contagion. This strain was largely confined to Asia. The bubonic plague was endemic in populations of infected ground rodents in Central Asia and was a known cause of death among the migrant and established human populations in that region for centuries. An influx of new people because of political conflicts and global trade led to

5625-594: Was the usage of newly invented plague vaccines, with some in India being recorded to have an efficacy of over 50%. In many instances, the third plague pandemic either revealed or exacerbated major social conflicts and racial inequalities. Many of the ports infected during the plague were at the time in British colonies. Because of this, the British authorities often ended up enforcing western hygiene and medical practices and radical quarantine measures in countries and provinces such as India, South Africa and Hong Kong. In India harsh quarantines were initially implemented by

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