A brush is a common tool with bristles, wire or other filaments. It consists of a handle or block to which filaments are affixed in either a parallel or perpendicular orientation, depending on the way the brush is to be gripped during use; the material of both the block and bristles or filaments is chosen to withstand hazards of its intended use, such as corrosive chemicals, heat or abrasion. It is used for cleaning, grooming hair, make up, surface finishing and for many other purposes, it is one of the most basic and versatile tools in use today, the average household may contain several dozen varieties. A common way of setting the bristles, brush filaments, in the brush is the staple or anchor set brush in which the filament is forced with a staple by the middle into a hole with a special driver and held there by the pressure against all of the walls of the hole and the portions of the staple nailed to the bottom of the hole; the staple can be replaced with a kind of anchor, a piece of rectangular profile wire, anchored to the wall of the hole, like in most toothbrushes.
Another way to attach the bristles to the surface can be found in a fused brush, in which instead of being inserted into a hole, a plastic fibre is welded to another plastic surface, giving the option to use different diameters of bristles in the same brush. Configurations include twisted-in wire and disks; the action of these brushes is in the tip of each flexible bristle which dislodges particles of matter. Toothbrush Floor brush Scrubber Shoe-polish brush Curling brush Nailbrush Milk-churn brush Vacuum-cleaner brush Vegetable brush Archaeology brush Lavatory brush Clothes brush, a brush for removing detritritus from clothing Chip brush Car-wash brush Gun-barrel brush Wire brush Typewriter eraser brush Dandy brush, for Horse grooming Dishwashing brush Beekeeper's brush Bench-grinder brush Rotary brush Flue brush Chimney brush Bottle brush - a long handled brush with rows of radial bristles, designed to fit into small mouthed bottles and access the larger interior. Broom The action of such brushes is from the sides, not the tip, contact with which releases material held by capillary action.
Paintbrush Paintbrush Wall-paper brush Shoe-polish brush Makeup brush Mascara brush Nail-polish brush Finger-print forensic brush Pastry brush Ink brush Shaving brush Gilding brush The action of these brushes is more akin to combing than brushing, they are used to straighten and untangle filaments. Certain varieties of hairbrush are however designed to brush the scalp itself free of material such as dead skin and to invigorate the skin of the scalp. Hair brush Dog-grooming brush Cat fur brush Brush, used on electrical motors Brush percussion mallets Magnetic brush Stippling brush Medical sampling brush Brushes used for cleaning come in various sizes, ranging from that of a toothbrush, to the standard household version accompanied by a dustpan, to 36" deck brushes. There are brushes for cleaning tiny cracks and crevices and brushes for cleaning enormous warehouse floors. Brushes perform a multitude of cleaning tasks. For example, brushes dust the tiniest figurine, they help scrub stains out of clothing and shoes, they remove grime from tires, they remove the dirt and debris found on floors with the help of a dust pan.
Specific brushes are used for diverse activities from cleaning vegetables, as a toilet brush, washing glass, cleaning tiles, as a mild abrasive for sanding. Wire brush Hairbrush Ink brush Pastry brush Test tube brush The Grove Encyclopedia of Materials and Techniques in Art, Gerald W. R. Ward. Oxford University Press, 2008. ISBN 978-0-19-531391-8Glossary of Brush Terms
Sri Lanka the Democratic Socialist Republic of Sri Lanka, is an island country in South Asia, located in the Indian Ocean to the southwest of the Bay of Bengal and to the southeast of the Arabian Sea. The island is geographically separated from the Indian subcontinent by the Gulf of Mannar and the Palk Strait; the legislative capital, Sri Jayawardenepura Kotte, is a suburb of the commercial capital and largest city, Colombo. Sri Lanka's documented history spans 3,000 years, with evidence of pre-historic human settlements dating back to at least 125,000 years, it has a rich cultural heritage and the first known Buddhist writings of Sri Lanka, the Pāli Canon, date back to the Fourth Buddhist council in 29 BC. Its geographic location and deep harbours made it of great strategic importance from the time of the ancient Silk Road through to the modern Maritime Silk Road. Sri Lanka was known from the beginning of British colonial rule as Ceylon. A nationalist political movement arose in the country in the early 20th century to obtain political independence, granted in 1948.
Sri Lanka's recent history has been marred by a 26-year civil war, which decisively ended when the Sri Lanka Armed Forces defeated the Liberation Tigers of Tamil Eelam in 2009. The current constitution stipulates the political system as a republic and a unitary state governed by a semi-presidential system, it has had a long history of international engagement, as a founding member of the South Asian Association for Regional Cooperation, a member of the United Nations, the Commonwealth of Nations, the G77, the Non-Aligned Movement. Along with the Maldives, Sri Lanka is one of only two South Asian countries rated "high" on the Human Development Index, with its HDI rating and per capita income the highest among South Asian nations; the Sri Lankan constitution accords Buddhism the "foremost place", although it does not identify it as a state religion. Buddhism is given special privileges in the Sri Lankan constitution; the island is home to many cultures and ethnicities. The majority of the population is from the Sinhalese ethnicity, while a large minority of Tamils have played an influential role in the island's history.
Moors, Malays and the indigenous Vedda are established groups on the island. In antiquity, Sri Lanka was known to travellers by a variety of names. According to the Mahavamsa, the legendary Prince Vijaya named the land Tambapanni, because his followers' hands were reddened by the red soil of the area. In Hindu mythology, such as the Ramayana, the island was referred to as Lankā; the Tamil term Eelam, was used to designate the whole island in Sangam literature. The island was known under Chola rule as Mummudi Cholamandalam. Ancient Greek geographers called it Taprobanē from the word Tambapanni; the Persians and Arabs referred to it as Sarandīb from Cerentivu or Siṃhaladvīpaḥ. Ceilão, the name given to Sri Lanka by the Portuguese Empire when it arrived in 1505, was transliterated into English as Ceylon; as a British crown colony, the island was known as Ceylon. The country is now known in Sinhala in Tamil as Ilaṅkai. In 1972, its formal name was changed to "Free and Independent Republic of Sri Lanka".
In 1978 it was changed to the "Democratic Socialist Republic of Sri Lanka". As the name Ceylon still appears in the names of a number of organisations, the Sri Lankan government announced in 2011 a plan to rename all those over which it has authority; the pre-history of Sri Lanka goes back 125,000 years and even as far back as 500,000 years. The era spans the Palaeolithic and early Iron Ages. Among the Paleolithic human settlements discovered in Sri Lanka, which dates back to 37,000 BP, Batadombalena and Belilena are the most important. In these caves, archaeologists have found the remains of anatomically modern humans which they have named Balangoda Man, other evidence suggesting that they may have engaged in agriculture and kept domestic dogs for driving game. One of the first written references to the island is found in the Indian epic Ramayana, which provides details of a kingdom named Lanka, created by the divine sculptor Vishwakarma for Kubera, the Lord of Wealth, it is said that Kubera was overthrown by his demon stepbrother Ravana, the powerful emperor who built a mythical flying machine named Dandu Monara.
The modern city of Wariyapola is described as Ravana's airport. Early inhabitants of Sri Lanka were ancestors of the Vedda people, an indigenous people numbering 2,500 living in modern-day Sri Lanka; the 19th-century Irish historian James Emerson Tennent theorized that Galle, a city in southern Sri Lanka, was the ancient seaport of Tarshish from which King Solomon is said to have drawn ivory and other valuables. According to the Mahāvamsa, a chronicle written in Pāḷi, the original inhabitants of Sri Lanka are the Yakshas and Nagas. Ancient cemeteries that were used before 600 BC and other signs of advanced civilisation have been discovered in Sri Lanka. Sinhalese history traditionally starts in 543 BC with the arrival of Prince Vijaya, a semi-legendary prince who sailed with 700 followers to Sri Lanka, after being expelled from Vanga Kingdom (present-day Ben
A snail is, in loose terms, a shelled gastropod. The name is most applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name snail is used for most of the members of the molluscan class Gastropoda that have a coiled shell, large enough for the animal to retract into; when the word "snail" is used in this most general sense, it includes not just land snails but numerous species of sea snails and freshwater snails. Gastropods that lack a shell, or have only an internal shell, are called slugs, land snails that have only a small shell are called semi-slugs. Snails have considerable human relevance, including as food items, as pests, as vectors of disease, their shells are used as decorative objects and are incorporated into jewelry; the snail has had some cultural significance, has been used as a metaphor. Snails that respire using a lung belong to the group Pulmonata; as traditionally defined, the Pulmonata were found to be polyphyletic in a molecular study per Jörger et al. dating from 2010.
But snails with gills form a polyphyletic group. Both snails that have lungs and snails that have gills have diversified so over geological time that a few species with gills can be found on land and numerous species with lungs can be found in freshwater. A few marine species have lungs. Snails can be found in a wide range of environments, including ditches and the abyssal depths of the sea. Although land snails may be more familiar to laymen, marine snails constitute the majority of snail species, have much greater diversity and a greater biomass. Numerous kinds of snail can be found in fresh water. Most snails have thousands of microscopic tooth-like structures located on a banded ribbon-like tongue called a radula; the radula works like a file. Many snails are herbivorous, eating plants or rasping algae from surfaces with their radulae, though a few land species and many marine species are omnivores or predatory carnivores. Snails cannot absorb colored pigments when eating paper or cardboard so their feces are colored.
Several species of the genus Achatina and related genera are known as giant African land snails. The largest living species of sea snail is Syrinx aruanus; the snail Lymnaea makes decisions by using only two types of neuron: one deciding whether the snail is hungry, the other deciding whether there is food in the vicinity. The largest known land gastropod is the African giant snail Achatina achatina, the largest recorded specimen of which measured 39.3 centimetres from snout to tail when extended, with a shell length of 27.3 cm in December 1978. It weighed 900 g. Named Gee Geronimo, this snail was owned by Christopher Hudson of Hove, East Sussex, UK, was collected in Sierra Leone in June 1976. Gastropods that lack a conspicuous shell are called slugs rather than snails; some species of slug have a red shell, some have only an internal vestige that serves as a calcium repository, others have no shell at all. Other than that there is little morphological difference between slugs and snails. There are however important differences in habitats and behavior.
A shell-less animal is much more maneuverable and compressible, so quite large land slugs can take advantage of habitats or retreats with little space, retreats that would be inaccessible to a similar-sized snail. Slugs squeeze themselves into confined spaces such as under loose bark on trees or under stone slabs, logs or wooden boards lying on the ground. In such retreats they are in less danger from either predators or desiccation, those are suitable places for laying their eggs. Slugs as a group are far from monophyletic; the reduction or loss of the shell has evolved many times independently within several different lineages of gastropods. The various taxa of land and sea gastropods with slug morphology occur within numerous higher taxonomic groups of shelled species. Land snails are known as an agricultural and garden pest but some species are an edible delicacy and household pets. There are a variety of snail-control measures that gardeners and farmers use in an attempt to reduce damage to valuable plants.
Traditional pesticides are still used, as are many less toxic control options such as concentrated garlic or wormwood solutions. Copper metal is a snail repellent, thus a copper band around the trunk of a tree will prevent snails from climbing up and reaching the foliage and fruit. Placing crushed egg shells on the soil around garden plants can deter snails from coming to the plants; the decollate snail will capture and eat garden snails, because of this it has sometimes been introduced as a biological pest control agent. However, this is not without problems, as the decollate snail is just as to attack and devour other gastropods that may represent a valuable part of the native fauna of the region. In French cuisine, edible snails are served for instance in Escargot à la Bourguignonne; the practice of rearing snails for food is known as heliciculture. For purposes of cultivation, the snails are kept in a
Peat known as turf, is an accumulation of decayed vegetation or organic matter. It is unique to natural areas called peatlands, mires, moors, or muskegs; the peatland ecosystem is the most efficient carbon sink on the planet, because peatland plants capture CO2 released from the peat, maintaining an equilibrium. In natural peatlands, the "annual rate of biomass production is greater than the rate of decomposition", but it takes "thousands of years for peatlands to develop the deposits of 1.5 to 2.3 m, the average depth of the boreal peatlands". Sphagnum moss called peat moss, is one of the most common components in peat, although many other plants can contribute; the biological features of Sphagnum mosses act to create a habitat aiding peat formation, a phenomenon termed'habitat manipulation'. Soils consisting of peat are known as histosols. Peat forms in wetland conditions, where flooding obstructs the flow of oxygen from the atmosphere, slowing the rate of decomposition. Peatlands bogs, are the primary source of peat, although less-common wetlands including fens and peat swamp forests deposit peat.
Landscapes covered in peat are home to specific kinds of plants including Sphagnum moss, ericaceous shrubs, sedges. Because organic matter accumulates over thousands of years, peat deposits provide records of past vegetation and climate by preserving plant remains, such as pollen; this allows humans to reconstruct past environments and study changes in human land use. Peat is harvested as an important source of fuel in certain parts of the world. By volume, there are about 4 trillion cubic metres of peat in the world, covering a total of around 2% of the global land area, containing about 8 billion terajoules of energy. Over time, the formation of peat is the first step in the geological formation of other fossil fuels such as coal low-grade coal such as lignite. Depending on the agency, peat is not regarded as a renewable source of energy, due to its extraction rate in industrialized countries far exceeding its slow regrowth rate of 1 mm per year, as it is reported that peat regrowth takes place only in 30-40% of peatlands.
Because of this, the UNFCCC, another organization affiliated with the United Nations classified peat as a fossil fuel. However, the Intergovernmental Panel on Climate Change has begun to classify peat as a "slowly renewable" fuel; this is the classification used by many in the peat industry. At 106 g CO2/MJ, the carbon dioxide emission intensity of peat is higher than that of coal and natural gas. Peat forms when plant material does not decay in acidic and anaerobic conditions, it is composed of wetland vegetation: principally bog plants including mosses and shrubs. As it accumulates, the peat holds water; this creates wetter conditions that allow the area of wetland to expand. Peatland features can include ponds and raised bogs. Most modern peat bogs formed 12,000 years ago in high latitudes after the glaciers retreated at the end of the last ice age. Peat accumulates at the rate of about a millimetre per year. Peat material is either hemic, or sapric. Fibric peats are the least consist of intact fibre.
Hemic peats are decomposed and sapric are the most decomposed. Phragmites peat are composed of reed grass, Phragmites australis, other grasses, it is denser than many other types of peat. Engineers may describe a soil as peat which has a high percentage of organic material; this soil is problematic because it exhibits poor consolidation properties – it cannot be compacted to serve as a stable foundation to support loads, such as roads or buildings. In a cited article and Clarke defined peatlands or mires as...the most widespread of all wetland types in the world, representing 50 to 70% of global wetlands. They cover over 3 % of the land and freshwater surface of the planet. In these ecosystems are found one third of the world’s soil carbon and 10% of global freshwater resources; these ecosystems are characterized by the unique ability to accumulate and store dead organic matter from Sphagnum and many other non-moss species, as peat, under conditions of permanent water saturation. Peatlands are adapted to the extreme conditions of high water and low oxygen content, of toxic elements and low availability of plant nutrients.
Their water chemistry varies from alkaline to acidic. Peatlands occur on all continents, from the tropical to boreal and Arctic zones from sea level to high alpine conditions. Peatlands are areas of land with formed layers of peat, they can cover around 4 million square kilometres. In Europe, peatlands extend to about 515,000 km2. About 60% of the world's wetlands are made of peat. Peat deposits are found in many places around the world, including northern Europe and North America; the North American peat deposits are principally found in the Northern United States. Some of the world's largest peatlands include the West Siberian Lowland, the Hudson Bay Lowlands, the Mackenzie River Valley. There is less peat in part because there is less land; that said, the vast Magellanic Moorland in South America is an extensive peat-dominated landscape. Peat can be found in New Zealand
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms, an allergen is an antigen, capable of stimulating a type-I hypersensitivity reaction in atopic individuals through Immunoglobulin E responses. Most humans mount significant Immunoglobulin E responses only as a defense against parasitic infections. However, some individuals may respond to many common environmental antigens; this hereditary predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. Sensitivities vary from one person to another. A broad range of substances can be allergens to sensitive individuals. Allergens can be found in a variety of sources, such as dust mite excretion, pet dander, or royal jelly. Food allergies are not as common as food sensitivity, but some foods such as peanuts, nuts and shellfish are the cause of serious allergies in many people.
The United States Food and Drug Administration does recognize eight foods as being common for allergic reactions in a large segment of the sensitive population. These include peanuts, tree nuts, milk, fish and their derivatives, soy and their derivatives, as well as sulfites at 10ppm and over. See the FDA website for complete details. Other countries, in view of the differences in the genetic profiles of their citizens and different levels of exposure to specific foods due to different dietary habits, the "official" allergen list will change. Canada recognizes all eight of the allergens recognized by the US, recognizes sesame seeds, mustard; the European Union additionally recognizes other gluten-containing cereals as well as celery and lupin. Another allergen is urushiol, a resin produced by poison ivy and poison oak, which causes the skin rash condition known as urushiol-induced contact dermatitis by changing a skin cell's configuration so that it is no longer recognized by the immune system as part of the body.
Various trees and wood products such as paper, cardboard, MDF etc. can cause mild to severe allergy symptoms through touch or inhalation of sawdust such as asthma and skin rash. An allergic reaction can be caused by any form of direct contact with the allergen—consuming food or drink one is sensitive to, breathing in pollen, perfume or pet dander, or brushing a body part against an allergy-causing plant. Other common causes of serious allergy are wasp, fire ant and bee stings and latex. An serious form of an allergic reaction is called anaphylaxis. One form of treatment is the administration of sterile epinephrine to the person experiencing anaphylaxis, which suppresses the body's overreaction to the allergen, allows for the patient to be transported to a medical facility. In addition to foreign proteins found in foreign serum and vaccines, common allergens include: Animal products Fel d 1 fur and dander cockroach calyx wool dust mite excretion Drugs penicillin sulfonamides salicylates Foods celery and celeriac corn or maize eggs fruit pumpkin, egg-plant legumes beans peas peanuts soybeans milk seafood sesame soy tree nuts pecans almonds wheat Insect stings bee sting venom wasp sting venom mosquito stings Mold spores Top 5 allergens discovered in patch tests in 2005–06: nickel sulfate Balsam of Peru fragrance mix I quaternium-15, neomycin.
Metals Nickel Chromium Other latex wood Plant pollens grass — ryegrass, timothy-grass weeds — ragweed, nettle, Artemisia vulgaris, Chenopodium album, sorrel trees — birch, hazel, Aesculus, poplar, Tilia, Ashe juniper, Alstonia scholaris Seasonal allergy symptoms are experienced during specific parts of the year during spring, summer or fall when certain trees or grasses pollinate. This depends on the kind of grass. For instance, some trees such as oak and maple pollinate in the spring, while grasses such as Bermuda and orchard pollinate in the summer. Grass allergy is linked to hay fever because their symptoms and causes are somehow similar to each other. Symptoms include rhinitis, which causes sneezing and a runny nose, as well as allergic conjunctivitis, which includes watering and itchy eyes. An initial tickle on the roof of the mouth or in the back of the throat may be experienced. Depending on the season, the symptoms may be more severe and people may experience coughing and irritability.
A few people become depressed, lose their appetite, or have problems sleeping. Moreover, since the sinuses may become congested, some people experience headaches. If both parents suffered from allergies in the past, there is a 66% chance for the individual to suffer from seasonal allergies, the risk lowers to 60% if just one parent had suffered from allergies; the immune system has strong influence on seasonal allergies, since it reacts differently to diverse allergens like pollen. When an allergen enters the body of an individual, predisposed to allergies, it triggers an immune reaction and the production of antibodies; these allergen antibodies migrate to mast cells lining the nose and lungs. When an allergen drifts into the nose more than once, mast cells release a slew of chemicals or histamines that irritate and inflame the moist membranes lining the nose and produ
Magnesium sulfate is an inorganic salt with the formula MgSO4x where 0≤x≤7. It is encountered as the heptahydrate sulfate mineral epsomite called Epsom salt; the overall global annual usage in the mid-1970s of the monohydrate was 2.3 million tons, of which the majority was used in agriculture. Epsom salt has been traditionally used as a component of bath salts. Epsom salt can be used as a beauty product. Athletes use it to soothe sore muscles, it has a variety of other uses: for example, Epsom salt is effective in the removal of splinters. A variety of hydrates are known; the heptahydrate loses one equivalent of water to form the hexahydrate. Epsom salt takes its name from a bitter saline spring in Epsom in Surrey, where the salt was produced from the springs that arise where the porous chalk of the North Downs meets non-porous London clay; the monohydrate, MgSO4·H2O is found as the mineral kieserite. It can be prepared by heating the hexahydrate to 150 °C. Further heating to 200 °C gives anhydrous magnesium sulfate.
Upon further heating, the anhydrous salt decomposes into magnesium sulfur trioxide. The heptahydrate can be prepared by neutralizing sulfuric acid with magnesium carbonate or oxide, but it is obtained directly from natural sources, it is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. Magnesium sulfate is a common mineral pharmaceutical preparation of magnesium known as Epsom salt, used both externally and internally. Magnesium sulfate is water-soluble and solubility is inhibited with lipids used in lotions. Lotions employ the use of emulsions or suspensions to include both oil and water-soluble ingredients. Hence, magnesium sulfate in a lotion may not be as available to migrate to the skin nor to be absorbed through the skin, hence both studies may properly suggest absorption or lack thereof as a function of the carrier. Temperature and concentration gradients may be contributing factors to absorption. Externally, magnesium sulfate paste is used to treat skin inflammations such as small boils or localised infections.
Known in the UK as "drawing paste", it is used to remove splinters. The standard British Pharmacopoeia composition is dried Magnesium Sulfate 47.76 % w/w, Phenol 0.49 % w/w. and glycerol. Epsom salt is used for isolation tanks. Magnesium sulfate is the main preparation of intravenous magnesium. Internal uses include: Oral magnesium sulfate is used as a saline laxative or osmotic purgative. Replacement therapy for hypomagnesemia Magnesium sulfate is a antiarrhythmic agent for torsades de pointes in cardiac arrest under the ECC guidelines and for managing quinidine-induced arrhythmias; as a bronchodilator after beta-agonist and anticholinergic agents have been tried, e.g. in severe exacerbations of asthma, magnesium sulfate can be nebulized to reduce the symptoms of acute asthma. It is administered via the intravenous route for the management of severe asthma attacks. Magnesium sulfate is effective in decreasing the risk. IV magnesium sulfate is used to treat seizures of eclampsia, it reduces the systolic blood pressure but doesn't alter the diastolic blood pressure, so the blood perfusion to the fetus isn't compromised.
It is commonly used for eclampsia where compared to diazepam or phenytoin it results in better outcomes. In agriculture, magnesium sulfate is used to increase sulfur content in soil, it is most applied to potted plants, or to magnesium-hungry crops, such as potatoes, tomatoes, lemon trees and peppers. The advantage of magnesium sulfate over other magnesium soil amendments is its high solubility, which allows the option of foliar feeding. Solutions of magnesium sulfate are nearly neutral, compared with alkaline salts of magnesium as found in limestone. Magnesium sulfate is used as a brewing salt in making beer, it may be used as a coagulant for making tofu. Anhydrous magnesium sulfate is used as a desiccant in organic synthesis due to its affinity for water. During work-up, an organic phase is treated with anhydrous magnesium sulfate; the hydrated solid is removed with filtration or decantation. Other inorganic sulfate salts such as sodium sulfate and calcium sulfate may be used in the same way. Magnesium sulfate heptahydrate is used to maintain the magnesium concentration in marine aquaria which contain large amounts of stony corals, as it is depleted in their calcification process.
In a magnesium-deficient marine aquarium and alkalinity concentrations are difficult to control because not enough magnesium is present to stabilize these ions in the saltwater and prevent their spontaneous precipitation into calcium carbonate. Magnesium sulfates are common minerals in geological environments, their occurrence is connected with supergene processes. Some of them are important constituents of evaporitic potassium-magnesium salts deposits. Bright spots observed by the Dawn Spacecraft in Occator Crater on the dwarf planet Ceres are most consistent with reflected light from magnesium sulfate hexahydrate. All known mineralogical forms of MgSO4 are hydrates. Epsomite is the natural analogue of "Epsom salt". Another heptahydrate, the copper-containing mineral alpersite SO4·7H2O, was recognized. Both are, not the highest known hydrates of MgSO4, du
The coconut tree is a member of the palm tree family and the only living species of the genus Cocos. The term "coconut" can refer to the whole coconut palm, the seed, or the fruit, which botanically is a drupe, not a nut; the term is derived from the 16th-century Portuguese and Spanish word coco meaning "head" or "skull" after the three indentations on the coconut shell that resemble facial features. Coconuts are known for their versatility of uses; the inner flesh of the mature seed forms a regular part of the diets of many people in the tropics and subtropics. Coconuts are distinct from other fruits because their endosperm contains a large quantity of clear liquid, called "coconut milk" in the literature, when immature, may be harvested for their potable "coconut water" called "coconut juice". Mature, ripe coconuts can be used as edible seeds, or processed for oil and plant milk from the flesh, charcoal from the hard shell, coir from the fibrous husk. Dried coconut flesh is called copra, the oil and milk derived from it are used in cooking – frying in particular – as well as in soaps and cosmetics.
The hard shells, fibrous husks and long pinnate leaves can be used as material to make a variety of products for furnishing and decorating. The coconut has cultural and religious significance in certain societies in India, where it is used in Hindu rituals; the name coconut derives from seafarers during the 16th and 17th century for its resemblance to a head.'Coco' and'coconut' came from 1521 encounters by Portuguese and Spanish explorers with Pacific islanders, with the coconut shell reminding them of a ghost or witch in Portuguese folklore called coco. The specific name nucifera is Latin for "nut-bearing". Literary evidence from the Ramayana and Sri Lankan chronicles indicates that the coconut was present in South Asia before the 1st century BCE. Another early mention of the coconut dates back to the "One Thousand and One Nights" story of Sinbad the Sailor. Thenga, its Tamil name, was used in the detailed description of coconut found in Itinerario by Ludovico di Varthema published in 1510 and in the Hortus Indicus Malabaricus.
Earlier, it was called nux indica, a name used by Marco Polo in 1280 while in Sumatra, taken from the Arabs who called it jawz hindī, translating to "Indian nut". In the earliest description of the coconut palm known, given by Cosmos of Alexandria in his Topographia Christiana written around 545, there is a reference to the argell tree and its drupe. In March 1521, a description of the coconut was given by Antonio Pigafetta writing in Italian and using the words "cocho"/"cochi", as recorded in his journal after the first European crossing of the Pacific Ocean during the Magellan circumnavigation and meeting the inhabitants of what would become known as Guam and the Philippines, he explained how at Guam "they eat coconuts" and that the natives there "anoint the body and the hair with coconut and beniseed oil". The American botanist Orator F. Cook was one of the earliest modern researchers to propose a hypothesis in 1901 on the location of the origin of Cocos nucifera based on its current worldwide distribution.
He hypothesized that the coconut originated in the Americas, based on his belief that American coconut populations predated European contact and because he considered pan-tropical distribution by ocean currents improbable. Thor Heyerdahl used this as one part of his 1950 hypothesis to support his theory that the Pacific Islanders originated as two migration streams from the Canadian Pacific coast to Hawaii, on to Tahiti and New Zealand in a series of hops, another migration of a bearded and more advanced "white race" from South America via sailing balsa-wood rafts. Physical and genetic evidence, have overwhelmingly proven that Pacific Islanders originated from the eastward branch of the expansion of Austronesian peoples from Island Southeast Asia and Taiwan using more sophisticated outrigger canoe technology, not from the Americas. Genetic studies have identified the center of origin of coconuts as being the region between Southwest Asia and Melanesia, where it shows greatest genetic diversity.
Their cultivation and spread was tied to the early migrations of the Austronesian peoples who carried coconuts as canoe plants to islands they settled. The similarities of the local names in the Austronesian region is cited as evidence that the plant originated in the region. For example, the Polynesian and Melanesian term niu. A study in 2011 identified two genetically differentiated subpopulations of coconuts, one originating from Island Southeast Asia and the other from the southern margins of the Indian subcontinent; the Pacific group is the only one to display clear genetic and phenotypic indications that they were domesticated. The distribution of the Pacific coconuts correspond to the regions settled by Austronesian voyagers indicating that its spread was the result of human introductions, it is most strikingly displayed in Madagascar, an island settled by Austronesian sailors at around 2000 to 1500 BP. The coconut populations in the island show genetic admixture between the two subpopulations indicating that Pacific coconuts were brought by the Austronesian settlers