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63-511: There are various mountains and tourist destinations on the shores of the lake including Monte Brè to the east, Monte San Salvatore west of Lugano, and Monte Generoso on the south-eastern shore. The World Heritage Site Monte San Giorgio is situated south of the lake. Also located to the south is the Cinque Vette Park . The lake is drained by the Tresa , which empties into Lake Maggiore ,

126-594: A concentration in the Earth's crust of about 0.1%, less abundant than hydrogen but more than manganese . In minerals, phosphorus generally occurs as phosphate . Elemental phosphorus was first isolated as white phosphorus in 1669. In white phosphorus, phosphorus atoms are arranged in groups of 4, written as P 4 . White phosphorus emits a faint glow when exposed to oxygen – hence, a name, taken from Greek mythology, Φωσφόρος meaning 'light-bearer' (Latin Lucifer ), referring to

189-424: A conductor of electricity, and has puckered sheets of linked atoms. Another form, scarlet phosphorus, is obtained by allowing a solution of white phosphorus in carbon disulfide to evaporate in sunlight . When first isolated, it was observed that the green glow emanating from white phosphorus would persist for a time in a stoppered jar, but then cease. Robert Boyle in the 1680s ascribed it to "debilitation" of

252-426: A fertiliser in its pure form or part of being mixed with water in the form of sewage or sewage sludge . The most prevalent compounds of phosphorus are derivatives of phosphate (PO 4 ), a tetrahedral anion. Phosphate is the conjugate base of phosphoric acid, which is produced on a massive scale for use in fertilisers. Being triprotic, phosphoric acid converts stepwise to three conjugate bases: Phosphate exhibits

315-451: A mountain, mountain range, or peak located in Ticino is a stub . You can help Misplaced Pages by expanding it . Phosphorus Phosphorus is a chemical element ; it has symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus , but because it is highly reactive , phosphorus is never found as a free element on Earth. It has

378-711: A problem in Lake Lugano. In the 1960s and 1970s it was officially forbidden to bathe in the lake. Despite the continued introduction of sewage treatment plants , such as in Gandria , factors, such as lake retention time and lack of oxygen and increasing phosphorus concentrations, means it is unclear if the lake will recover. The Federal Office for the Environment 's last published report on Lake Lugano dates from 1995. To summarise that report: The Swiss-Italian organisation CIPAIS in its most recent published report says: Considering

441-471: A source of P in routes to organophosphorus(III) compounds. For example, it is the precursor to triphenylphosphine : Treatment of phosphorus trihalides with alcohols and phenols gives phosphites, e.g. triphenylphosphite : Similar reactions occur for phosphorus oxychloride , affording triphenylphosphate : The name Phosphorus in Ancient Greece was the name for the planet Venus and is derived from

504-433: A tendency to form chains and rings containing P-O-P bonds. Many polyphosphates are known, including ATP . Polyphosphates arise by dehydration of hydrogen phosphates such as HPO 4 and H 2 PO 4 . For example, the industrially important pentasodium triphosphate (also known as sodium tripolyphosphate , STPP) is produced industrially by the megatonne by this condensation reaction : Phosphorus pentoxide (P 4 O 10 )

567-586: A transient intermediate in solution by thermolysis of organophosphorus precursor reagents. At still higher temperatures, P 2 dissociates into atomic P. Red phosphorus is polymeric in structure. It can be viewed as a derivative of P 4 wherein one P-P bond is broken, and one additional bond is formed with the neighbouring tetrahedron resulting in chains of P 21 molecules linked by van der Waals forces . Red phosphorus may be formed by heating white phosphorus to 250 °C (482 °F) or by exposing white phosphorus to sunlight. Phosphorus after this treatment

630-578: A variant of the Michaelis-Arbuzov reaction with electrophiles, instead reverting to another phosphorus(III) compound through a sulfonium intermediate. These compounds generally feature P–P bonds. Examples include catenated derivatives of phosphine and organophosphines. Compounds containing P=P double bonds have also been observed, although they are rare. Phosphides arise by reaction of metals with red phosphorus. The alkali metals (group 1) and alkaline earth metals can form ionic compounds containing

693-428: A white, waxy substance that glowed in the dark. Brand had discovered phosphorus. Specifically, Brand produced ammonium sodium hydrogen phosphate, (NH 4 )NaHPO 4 . While the quantities were essentially correct (it took about 1,100 litres [290 US gal] of urine to make about 60 g of phosphorus), it was unnecessary to allow the urine to rot first. Later scientists discovered that fresh urine yielded

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756-495: Is amorphous . Upon further heating, this material crystallises. In this sense, red phosphorus is not an allotrope, but rather an intermediate phase between the white and violet phosphorus, and most of its properties have a range of values. For example, freshly prepared, bright red phosphorus is highly reactive and ignites at about 300 °C (572 °F), though it is more stable than white phosphorus, which ignites at about 30 °C (86 °F). After prolonged heating or storage,

819-452: Is isoelectronic with SF 6 . The most important oxyhalide is phosphorus oxychloride , (POCl 3 ), which is approximately tetrahedral. Before extensive computer calculations were feasible, it was thought that bonding in phosphorus(V) compounds involved d orbitals. Computer modeling of molecular orbital theory indicates that this bonding involves only s- and p-orbitals. All four symmetrical trihalides are well known: gaseous PF 3 ,

882-442: Is a colourless gas and the molecules have trigonal bipyramidal geometry. PCl 5 is a colourless solid which has an ionic formulation of PCl 4 PCl 6 , but adopts the trigonal bipyramidal geometry when molten or in the vapour phase. PBr 5 is an unstable solid formulated as PBr 4 Br and PI 5 is not known. The pentachloride and pentafluoride are Lewis acids . With fluoride, PF 5 forms PF 6 , an anion that

945-456: Is a naturally occurring metal-rich phosphide found in meteorites. The structures of the metal-rich and phosphorus-rich phosphides can be complex. Phosphine (PH 3 ) and its organic derivatives (PR 3 ) are structural analogues of ammonia (NH 3 ), but the bond angles at phosphorus are closer to 90° for phosphine and its organic derivatives. Phosphine is an ill-smelling, toxic gas. Phosphorus has an oxidation number of −3 in phosphine. Phosphine

1008-402: Is aged or otherwise impure (e.g., weapons-grade, not lab-grade WP) is also called yellow phosphorus. White phosphorus is highly flammable and pyrophoric (self-igniting) in air; it faintly glows green and blue in the dark when exposed to oxygen. The autoxidation commonly coats samples with white phosphorus pentoxide ( P 4 O 10 ): P 4 tetrahedra, but with oxygen inserted between

1071-470: Is allowed at any of the 50 or so bathing establishments located along the Swiss shores. The Italian exclave of Campione d'Italia and parts of the waters of the lake are considered by European Customs Law as non-territorial for fiscal purposes and as such enjoy a special tax status as a duty-free area, exemption from EU VAT and offer residents other advantageous tax privileges. The Melide causeway separates

1134-548: Is also required. Shielding requires special consideration. The high energy of the beta particles gives rise to secondary emission of X-rays via Bremsstrahlung (braking radiation) in dense shielding materials such as lead. Therefore, the radiation must be shielded with low density materials such as acrylic or other plastic, water, or (when transparency is not required), even wood. In 2013, astronomers detected phosphorus in Cassiopeia ;A , which confirmed that this element

1197-404: Is an element essential to sustaining life largely through phosphates , compounds containing the phosphate ion, PO 4 . Phosphates are a component of DNA , RNA , ATP , and phospholipids , complex compounds fundamental to cells . Elemental phosphorus was first isolated from human urine , and bone ash was an important early phosphate source. Phosphate mines contain fossils because phosphate

1260-552: Is considered unstable, but is a product of crystalline phosphorus nitride decomposition at 1100 K. Similarly, H 2 PN is considered unstable, and phosphorus nitride halogens like F 2 PN, Cl 2 PN, Br 2 PN, and I 2 PN oligomerise into cyclic polyphosphazenes . For example, compounds of the formula (PNCl 2 ) n exist mainly as rings such as the trimer hexachlorophosphazene . The phosphazenes arise by treatment of phosphorus pentachloride with ammonium chloride: PCl 5 + NH 4 Cl → 1/ n (NPCl 2 ) n + 4 HCl When

1323-609: Is full of fish. Apart from a few protected areas, such as the mouth of the River Cuccio in Porlezza , fishing is allowed anywhere, although according to various regulations. Protected species are the bleak and the white clawed crayfish ( Austropotamobius pallipes ). The bleak is almost extinct here, unlike in Lago Maggiore, and planning is under way for the controlled repopulation of the lake, particularly around Ponte Tresa . In 1895

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1386-607: Is in Switzerland and 37% in Italy. It has an average width of roughly 1 km (0.62 mi) and a maximum width of about 3 km (1.9 mi) at the bay of Lugano. A maximum depth of 288 m (945 ft) is found in the northern basin. The culminating point of the lake's drainage basin is the Pizzo di Gino summit in the Lugano Prealps (2,245 m; 7,365 ft). Bathing in the lake

1449-548: Is navigable, and used by a considerable number of private vessels. Passenger boats of the Società Navigazione del Lago di Lugano (SNL) provide services on the lake, principally for tourist purposes, but also connecting Lugano with other lakeside communities, some of which have no road access. Fishery in the lake (and Lake Maggiore) is regulated by a 1986 agreement between Switzerland and Italy. The current agreement on navigation dates from 1992. Pollution has long been

1512-703: Is present in the fossilized deposits of animal remains and excreta. Low phosphate levels are an important limit to growth in a number of plant ecosystems. The vast majority of phosphorus compounds mined are consumed as fertilisers . Phosphate is needed to replace the phosphorus that plants remove from the soil, and its annual demand is rising nearly twice as fast as the growth of the human population. Other applications include organophosphorus compounds in detergents , pesticides , and nerve agents . Phosphorus has several allotropes that exhibit strikingly diverse properties. The two most common allotropes are white phosphorus and red phosphorus. For both pure and applied uses,

1575-858: Is produced by hydrolysis of calcium phosphide , Ca 3 P 2 . Unlike ammonia, phosphine is oxidised by air. Phosphine is also far less basic than ammonia. Other phosphines are known which contain chains of up to nine phosphorus atoms and have the formula P n H n +2 . The highly flammable gas diphosphine (P 2 H 4 ) is an analogue of hydrazine . Phosphorus oxoacids are extensive, often commercially important, and sometimes structurally complicated. They all have acidic protons bound to oxygen atoms, some have nonacidic protons that are bonded directly to phosphorus and some contain phosphorus–phosphorus bonds. Although many oxoacids of phosphorus are formed, only nine are commercially important, and three of them, hypophosphorous acid , phosphorous acid , and phosphoric acid , are particularly important. The PN molecule

1638-450: Is produced in supernovae as a byproduct of supernova nucleosynthesis . The phosphorus-to- iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general. In 2020, astronomers analysed ALMA and ROSINA data from the massive star-forming region AFGL 5142, to detect phosphorus-bearing molecules and how they are carried in comets to

1701-492: Is readily incorporated into bone and nucleic acids . For these reasons, Occupational Safety and Health Administration in the United States, and similar institutions in other developed countries require personnel working with P to wear lab coats, disposable gloves, and safety glasses or goggles to protect the eyes, and avoid working directly over open containers. Monitoring personal, clothing, and surface contamination

1764-469: Is stable and is therefore present at 100% abundance. The half-integer nuclear spin and high abundance of P make phosphorus-31 NMR spectroscopy a very useful analytical tool in studies of phosphorus-containing samples. Two radioactive isotopes of phosphorus have half-lives suitable for biological scientific experiments. These are: The high-energy beta particles from P penetrate skin and corneas and any P ingested, inhaled, or absorbed

1827-508: Is the acid anhydride of phosphoric acid, but several intermediates between the two are known. This waxy white solid reacts vigorously with water. With metal cations , phosphate forms a variety of salts. These solids are polymeric, featuring P-O-M linkages. When the metal cation has a charge of 2+ or 3+, the salts are generally insoluble, hence they exist as common minerals. Many phosphate salts are derived from hydrogen phosphate (HPO 4 ). PCl 5 and PF 5 are common compounds. PF 5

1890-416: Is the anhydride of P(OH) 3 , the minor tautomer of phosphorous acid. The structure of P 4 O 6 is like that of P 4 O 10 without the terminal oxide groups. Symmetric phosphorus(III) trithioesters (e.g. P(SMe) 3 ) can be produced from the reaction of white phosphorus and the corresponding disulfide , or phosphorus(III) halides and thiolates . Unlike the corresponding esters, they do not undergo

1953-524: Is the electrons are highly delocalized . This has been illustrated by calculations of the magnetically induced currents, which sum up to 29 nA/T, much more than in the archetypical aromatic molecule benzene (11 nA/T). White phosphorus exists in two crystalline forms: α (alpha) and β (beta). At room temperature, the α-form is stable. It is more common, has cubic crystal structure and at 195.2 K (−78.0 °C), it transforms into β-form, which has hexagonal crystal structure. These forms differ in terms of

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2016-512: Is the least reactive allotrope and the thermodynamically stable form below 550 °C (1,022 °F). It is also known as β-metallic phosphorus and has a structure somewhat resembling that of graphite . It is obtained by heating white phosphorus under high pressures (about 12,000 standard atmospheres or 1.2 gigapascals). It can also be produced at ambient conditions using metal salts, e.g. mercury, as catalysts. In appearance, properties, and structure, it resembles graphite , being black and flaky,

2079-728: Is today the chief commercial source of this element. According to the US Geological Survey (USGS) , about 50 percent of the global phosphorus reserves are in Amazigh nations like Morocco , Algeria and Tunisia . 85% of Earth's known reserves are in Morocco with smaller deposits in China , Russia , Florida , Idaho , Tennessee , Utah , and elsewhere. Albright and Wilson in the UK and their Niagara Falls plant, for instance, were using phosphate rock in

2142-524: The Greek words (φῶς = light, φέρω = carry), which roughly translates as light-bringer or light carrier. (In Greek mythology and tradition, Augerinus (Αυγερινός = morning star, still in use today), Hesperus or Hesperinus (΄Εσπερος or Εσπερινός or Αποσπερίτης = evening star, still in use today) and Eosphorus (Εωσφόρος = dawnbearer, not in use for the planet after Christianity) are close homologues, and also associated with Phosphorus-the-morning-star ). According to

2205-399: The brook trout was introduced from Lake Zug , while between 1894 and 1897 the common whitefish was introduced. Since 1950 attempts have been made to introduce the whitefish Coregonus macrophthalmus from Lake Neuchâtel , but it has not established itself effectively. The Common Roach is present in large numbers and took around ten years to colonise the entire lake, thereby replacing

2268-419: The phosphide ion, P . These compounds react with water to form phosphine . Other phosphides , for example Na 3 P 7 , are known for these reactive metals. With the transition metals as well as the monophosphides there are metal-rich phosphides, which are generally hard refractory compounds with a metallic lustre, and phosphorus-rich phosphides which are less stable and include semiconductors. Schreibersite

2331-447: The " Morning Star ", the planet Venus . The term phosphorescence , meaning glow after illumination, has its origin in phosphorus, although phosphorus itself does not exhibit phosphorescence: phosphorus glows due to oxidation of the white (but not red) phosphorus – a process now called chemiluminescence . Phosphorus is classified as a pnictogen , together with nitrogen , arsenic , antimony , bismuth , and moscovium . Phosphorus

2394-557: The 1890s and 1900s from Tennessee, Florida, and the Îles du Connétable ( guano island sources of phosphate); by 1950, they were using phosphate rock mainly from Tennessee and North Africa. Organic sources, namely urine , bone ash and (in the latter 19th century) guano , were historically of importance but had only limited commercial success. As urine contains phosphorus, it has fertilising qualities which are still harnessed today in some countries, including Sweden , using methods for reuse of excreta . To this end, urine can be used as

2457-497: The Oxford English Dictionary, the correct spelling of the element is phosphorus . The word phosphorous is the adjectival form of the P valence: so, just as sulfur forms sulfurous and sulfuric compounds, phosphorus forms phosphorous compounds (e.g., phosphorous acid ) and P valence phosphoric compounds (e.g., phosphoric acids and phosphates ). The discovery of phosphorus, the first element to be discovered that

2520-460: The aid of his assistant, Ambrose Godfrey-Hanckwitz . Godfrey later made a business of the manufacture of phosphorus. Boyle states that Kraft gave him no information as to the preparation of phosphorus other than that it was derived from "somewhat that belonged to the body of man". This gave Boyle a valuable clue, so that he, too, managed to make phosphorus, and published the method of its manufacture. Later he improved Brand's process by using sand in

2583-425: The air. In fact, this process is caused by the phosphorus reacting with oxygen in the air; in a sealed container, this process will eventually stop when all the oxygen in the container is consumed. By the 18th century, it was known that in pure oxygen, phosphorus does not glow at all; there is only a range of partial pressures at which it does. Heat can be applied to drive the reaction at higher pressures. In 1974,

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2646-469: The bleak. Still present are the European chub , tench , carp and a few examples of European perch , largemouth bass , zander and burbot . Recently the wels catfish and pigo have been spotted. The whole area behind the southern shores of Lake Lugano is rich in fossils. The focal point of these fossil deposits is Monte San Giorgio , where since the 19th century many fossils have been found dating from

2709-638: The chloride groups are replaced by alkoxide (RO ), a family of polymers is produced with potentially useful properties. Phosphorus forms a wide range of sulfides, where the phosphorus can be in P(V), P(III) or other oxidation states. The three-fold symmetric P 4 S 3 is used in strike-anywhere matches. P 4 S 10 and P 4 O 10 have analogous structures. Mixed oxyhalides and oxyhydrides of phosphorus(III) are almost unknown. Compounds with P-C and P-O-C bonds are often classified as organophosphorus compounds. They are widely used commercially. The PCl 3 serves as

2772-491: The color darkens (see infobox images); the resulting product is more stable and does not spontaneously ignite in air. Violet phosphorus is a form of phosphorus that can be produced by day-long annealing of red phosphorus above 550 °C. In 1865, Hittorf discovered that when phosphorus was recrystallised from molten lead , a red/purple form is obtained. Therefore, this form is sometimes known as "Hittorf's phosphorus" (or violet or α-metallic phosphorus). Black phosphorus

2835-413: The dark without burning. Although the term phosphorescence is derived from phosphorus, the reaction that gives phosphorus its glow is properly called chemiluminescence (glowing due to a cold chemical reaction), not phosphorescence (re-emitting light that previously fell onto a substance and excited it). There are 22 known isotopes of phosphorus, ranging from P to P . Only P

2898-401: The early Earth. Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). It is not found free in nature, but is widely distributed in many minerals , usually as phosphates. Inorganic phosphate rock , which is partially made of apatite (a group of minerals being, generally, pentacalcium triorthophosphate fluoride (hydroxide)),

2961-624: The flank of Monte Boglia (1,516 m) with a view of the bay of Lugano and the Pennine Alps and the Bernese Alps . It is considered one of the sunniest points in Switzerland . Since 1912, the Monte Brè funicular has led from Lugano Cassarate to Monte Brè. The village of Brè (800 m; population 300) lies on the eastern slope of Monte Brè and is connected to Lugano by bus service. The village shows

3024-523: The glow was explained by R. J. van Zee and A. U. Khan. A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming the short-lived molecules HPO and P 2 O 2 that both emit visible light. The reaction is slow and only very little of the intermediates are required to produce the luminescence, hence the extended time the glow continues in a stoppered jar. Since its discovery, phosphors and phosphorescence were used loosely to describe substances that shine in

3087-483: The lake and its shores became progressively incorporated into the Duchy of Milan they became the subject of political and territorial contention during the 15th century, and Lugano became the lake's main town. The lake definitively ceased to belong to a single sovereign political entity following the establishment of the transalpine bailiwicks of the Swiss cantons at the beginning of the 16th century. The Italian-Swiss border

3150-583: The latter being drained by the Ticino and the Po . The first certain testimony of a political body governing the shores of the lake is from 818. Occupying an area of strategic importance, the lake was then part of the feudal dominion of the County of Sperio. Circa 1000, it came under the control of the Bishop of Como . The region was the site of the war between Como and Milan over control of Alpine traffic from 1218 to 1227. As

3213-410: The mid- Triassic (around 220 million years ago). The deposits on Monte San Giorgio stretch towards the west into Italian territory and the deposits of Besano . Fossils dating from the early Jurassic (around 180 million years ago) have also been found along the southern shores but more towards the east and Osteno . Monte Br%C3%A8 Monte Brè (925 m) is a small mountain east of Lugano on

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3276-488: The most important allotrope is white phosphorus , often abbreviated WP. White phosphorus is a soft, waxy molecular solid composed of P 4 tetrahedra . This P 4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C (1,500 °F; 1,100 K) when it starts decomposing to P 2 molecules. The nature of bonding in this P 4 tetrahedron can be described by spherical aromaticity or cluster bonding, that

3339-432: The northern (27.5 km; 10.6 sq mi) and southern (21.4 km; 8.3 sq mi) basins , although a bridge in the causeway permits water flow and navigation. The lake retention time is an average of 8.2 years; that of the northern basin (11.9 years) is considerably higher than the southern one (2.3 years). Places on the lake in Switzerland (CH) and in Italy (I) include (from Lugano, clockwise): The lake

3402-439: The phosphorus atoms and at the vertices. White phosphorus is a napalm additive, and the characteristic odour of combustion is garlicky. White phosphorus is insoluble in water but soluble in carbon disulfide. Thermal decomposition of P 4 at 1100 K gives diphosphorus , P 2 . This species is not stable as a solid or liquid. The dimeric unit contains a triple bond and is analogous to N 2 . It can also be generated as

3465-434: The process produced a white material that glowed in the dark and burned brilliantly. It was named phosphorus mirabilis ("miraculous bearer of light"). Brand's process originally involved letting urine stand for days until it gave off a terrible stench. Then he boiled it down to a paste, heated this paste to a high temperature, and led the vapours through water, where he hoped they would condense to gold. Instead, he obtained

3528-427: The relative orientations of the constituent P 4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile , the least dense and the most toxic of the allotropes. White phosphorus gradually changes to red phosphorus, accelerated by light and heat. Samples of white phosphorus almost always contain some red phosphorus and accordingly appear yellow. For this reason, white phosphorus that

3591-469: The results obtained in 2009 it can be affirmed that, notwithstanding the observed improvement, Lake Lugano is still in a state of high eutrophication , the highest among Swiss lakes. The Italian environmental group Legambiente, in its 2007 study of all northern Italian lakes, found Lake Lugano to be the most polluted of all. All water samples were well beyond the legal limits. The polluted sites should not be bathed in for health reasons. Bacteria can cause in

3654-576: The same amount of phosphorus. Brand at first tried to keep the method secret, but later sold the recipe for 200 thalers to Johann Daniel Kraft ( de ) from Dresden. Kraft toured much of Europe with it, including England, where he met with Robert Boyle . The secret—that the substance was made from urine—leaked out, and Johann Kunckel (1630–1703) was able to reproduce it in Sweden (1678). Later, Boyle in London (1680) also managed to make phosphorus, possibly with

3717-421: The typical Ticinese architectural style. The traditional communal washing fountain or "Lavatoio" is still preserved. In the center of the old village is the "Path of Art" with notable artists. The Wilhelm Schmid Museum was the residence of the artist (1892–1971) and today contains a collection of his works. Schmid was the only Swiss painter of the northern Magical Realism style. This article about

3780-631: The worst case, skin infections, diarrhoea and vomiting. According to Legambiente, the only reason swimming was not banned on the Italian Lakes was because the state of Lombardy changed the law. They state that pollution levels in the lakes do not conform to European rulings and the lack of sewage treatment is illegal. Their 2010 measurements found samples taken at Ponte Tresa , Osteno and Porto Ceresio to be "heavily polluted" (more than 1,000 UFC/100 ml intestinal enterococci and/or greater than 2000 UFC/100 ml E. coli ). The lake

3843-439: The yellowish liquids PCl 3 and PBr 3 , and the solid PI 3 . These materials are moisture sensitive, hydrolysing to give phosphorous acid . The trichloride, a common reagent, is produced by chlorination of white phosphorus: The trifluoride is produced from the trichloride by halide exchange. PF 3 is toxic because it binds to haemoglobin . Phosphorus(III) oxide , P 4 O 6 (also called tetraphosphorus hexoxide)

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3906-620: Was fixed in 1752 by the Treaty of Varese, and has since remained virtually unchanged. In 1848, the Melide causeway was built on a moraine between Melide and Bissone , in order to carry a road across the lake and provide a direct connection between Lugano and Chiasso . Today the causeway also carries the Gotthard railway and the A2 motorway . The lake is 48.7 km (18.8 sq mi) in size, 63% of which

3969-539: Was not known since ancient times, is credited to the German alchemist Hennig Brand in 1669, although others might have discovered phosphorus around the same time. Brand experimented with urine , which contains considerable quantities of dissolved phosphates from normal metabolism. Working in Hamburg , Brand attempted to create the fabled philosopher's stone through the distillation of some salts by evaporating urine, and in

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