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Rose Madder
Rose madder (also known as madder) is a red paint made from the pigment madder lake, a traditional lake pigment extracted from the common madder plant ''Rubia tinctorum''. Madder lake contains two organic red dyes: alizarin and purpurin. As a paint, it has been described as a fugitive, transparent, nonstaining, mid valued, moderately dull violet red pigment in tints and medium solutions, darkening to an impermanent, dull magenta red in masstone. History Madder has been cultivated as a dyestuff since antiquity in Central Asia, South Asia, and Egypt, where it was grown as early as 1500 BC. Cloth dyed with madder root dye was found in the tomb of the Pharaoh Tutankhamun and on an Egyptian tomb painting from the Graeco-Roman period, diluted with gypsum to produce a pink color. It was also found in ancient Greece (in Corinth), and in Italy in the Baths of Titus and the ruins of Pompeii. It is referred to in the Talmud as well as mentioned in writings by Dioscoride ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purpurin (dye)
1,2,4-Trihydroxyanthraquinone, commonly called purpurin, is an anthraquinone. It is a naturally occurring red/yellow dye. It is formally derived from 9,10-anthraquinone by replacement of three hydrogen atoms by hydroxyl (OH) groups. Purpurin is also called verantin, smoke Brown G, hydroxylizaric acid, and C.I. 58205. It is a minor component of the classical lake pigment "madder lake" or Rose Madder. History Madder root has been used for dying cloth at least since 1500 BC.Madder Root'' catalog entry at Natural Pigments website. Accessed on 2010-01-22. Purpurin and alizarin were isolated from the root by Pierre Robiquet and Colin, two French chemists, in 1826. They were identified as anthracene derivatives by Gräbe and Liebermann in 1868. They also synthesized alizarin from bromoanthraquinone, which, together with the conversion of alizarin into purpurin published previously by M. F. De Lalande, provided the first synthetic route to purpurin. The positions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubia Tinctorum
''Rubia tinctorum'', the rose madder or common madder or dyer's madder, is a herbaceous perennial plant species belonging to the bedstraw and coffee family Rubiaceae. Description The common madder can grow up to 1.5 m in height. The evergreen leaves are approximately 5–10 cm long and 2–3 cm broad, produced in whorls of 4–7 starlike around the central stem. It climbs with tiny hooks at the leaves and stems. The flowers are small (3–5 mm across), with five pale yellow petals, in dense racemes, and appear from June to August, followed by small (4–6 mm diameter) red to black berries. The roots can be over a metre long, up to 12 mm thick and the source of red dyes known as rose madder and Turkey red. It prefers loamy soils (sand and clay soil) with a constant level of moisture. Madder is used as a food plant by the larvae of some Lepidoptera species including the hummingbird hawk moth. Uses It has been used since ancient times as a vegetab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baths Of Titus
The Baths of Titus or ''Thermae Titi'' were public baths (''Thermae'') built in 81 AD at Rome, by Roman emperor Titus. The baths sat at the base of the Esquiline Hill, an area of parkland and luxury estates which had been taken over by Nero (AD 54–68) for his Golden House or ''Domus Aurea''. Titus' baths were built in haste, possibly by converting an existing or partly built bathing complex belonging to the reviled ''Domus Aurea''. They were not particularly extensive, and the much larger Baths of Trajan were built immediately adjacent to them at the start of the next century. Description The Baths of Titus were the first of the "imperial" baths to use what would become a standard design for public bathing complexes in Rome in the 2nd and 3rd centuries AD.Sear, 1983; p. 40 The entire building was strictly symmetrical, and featured along its center axis from north to south the main bath chambers in a sequence: ''frigidarium'', ''tepidarium'', and ''caldarium''. As in the other ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre-Jean Robiquet
Pierre Jean Robiquet (13 January 1780 – 29 April 1840) was a French chemist. He laid founding work in identifying amino acids, the fundamental building blocks of proteins. He did this through recognizing the first of them, asparagine, in 1806, in the industry's adoption of industrial dyes, with the identification of alizarin in 1826, and in the emergence of modern medications, through the identification of codeine in 1832, a opiate alkaloid substance of widespread use with analgesic and antidiarrheal properties. Robiquet was born in Rennes. He was at first a pharmacist in the French armies during the French Revolution years and became a professor at the École de pharmacie in Paris, where he died. Notable scientific achievements were among other things his isolation and characterization of properties of asparagine (the first amino acid to be identified, from asparagus, achieved. In 1806, with Louis Nicolas Vauquelin), cantharidin (1810), the sigma-1 receptor agonist noscapin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared light. The name of the element is derived from the Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Industrial production of chromium proceeds from chromite ore (mostly FeCr2O4) to pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly of potassium carbonate, was mildly basic. After heating this substance with calcium hydroxide (''slaked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alum
An alum () is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula , where is a monovalent cation such as potassium or ammonium. By itself, "alum" often refers to potassium alum, with the formula . Other alums are named after the monovalent ion, such as sodium alum and ammonium alum. The name "alum" is also used, more generally, for salts with the same formula and structure, except that aluminium is replaced by another trivalent metal ion like chromium, and/or sulfur is replaced by another chalcogen like selenium. The most common of these analogs is chrome alum . In most industries, the name "alum" (or "papermaker's alum") is used to refer to aluminium sulfate, , which is used for most industrial flocculation (the variable is an integer whose size depends on the amount of water absorbed into the alum). In medicine, "alum" may also refer to aluminium hydroxide gel used as a vaccine adjuvant. History Alum found at a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Pigment
A lake pigment is a pigment made by precipitating a dye with an inert binder, or mordant, usually a metallic salt. Unlike vermilion, ultramarine, and other pigments made from ground minerals, lake pigments are organic.K. Hunger. W. Herbst "Pigments, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2012. Manufacturers and suppliers to artists and industry frequently omit the ''lake'' designation in the name. Many lake pigments are fugitive because the dyes involved are not lightfast. Red lakes were particularly important in Renaissance and Baroque paintings; they were often used as translucent glazes to portray the colors of rich fabrics and draperies.David Bomford and Ashok Roy, ''A Closer Look - Colour'', National Gallery Company, p. 41. Etymology The term "lake" is derived from the term lac, the secretions of the Indian wood insect '' Kerria lacca'' (formerly ''Laccifer lacca'' or ''Coccus lacca''). It has the same root as the word ''lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adjectival term applied to anatomical structures which are made primarily of calcium carbonate, in animals such as gastropods, i.e., snails, specifically about such structures as the operculum, the clausilium, and the love dart. The term also applies to the calcium carbonate tests of often more or less microscopic Foraminifera. Not all tests are calcareous; diatoms and radiolaria have siliceous tests. The molluscs are calcareous, as are calcareous sponges (Porifera), that have spicules which are made of calcium carbonate. In botany ''Calcareous grassland'' is a form of grassland characteristic of soils containing much calcium carbonate from underlying chalk or limestone rock. In medicine The term is used in pathology, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moors
The term Moor, derived from the ancient Mauri, is an exonym first used by Christian Europeans to designate the Muslim inhabitants of the Maghreb, the Iberian Peninsula, Sicily and Malta during the Middle Ages. Moors are not a distinct or self-defined people. The 1911 ''Encyclopædia Britannica'' observed that the term had "no real ethnological value." Europeans of the Middle Ages and the early modern period variously applied the name to Arabs and North African Berbers, as well as Muslim Europeans. The term has also been used in Europe in a broader, somewhat derogatory sense to refer to Muslims in general,Menocal, María Rosa (2002). ''Ornament of the World: How Muslims, Jews and Christians Created a Culture of Tolerance in Medieval Spain''. Little, Brown, & Co. , p. 241 especially those of Arab or Berber descent, whether living in Spain or North Africa. During the colonial era, the Portuguese introduced the names " Ceylon Moors" and " Indian Moors" in South Asia and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
