Cambridge University Press
Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by King Henry VIII in 1534, it is the world's oldest publishing house and the second-largest university press in the world, it holds letters patent as the Queen's Printer. The press mission is "to further the University's mission by disseminating knowledge in the pursuit of education and research at the highest international levels of excellence". Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. With a global sales presence, publishing hubs, offices in more than 40 countries, it publishes over 50,000 titles by authors from over 100 countries, its publishing includes academic journals, reference works and English language teaching and learning publications. Cambridge University Press is a charitable enterprise that transfers part of its annual surplus back to the university. Cambridge University Press is both the oldest publishing house in the world and the oldest university press.
It originated from letters patent granted to the University of Cambridge by Henry VIII in 1534, has been producing books continuously since the first University Press book was printed. Cambridge is one of the two privileged presses. Authors published by Cambridge have included John Milton, William Harvey, Isaac Newton, Bertrand Russell, Stephen Hawking. University printing began in Cambridge when the first practising University Printer, Thomas Thomas, set up a printing house on the site of what became the Senate House lawn – a few yards from where the press's bookshop now stands. In those days, the Stationers' Company in London jealously guarded its monopoly of printing, which explains the delay between the date of the university's letters patent and the printing of the first book. In 1591, Thomas's successor, John Legate, printed the first Cambridge Bible, an octavo edition of the popular Geneva Bible; the London Stationers objected strenuously. The university's response was to point out the provision in its charter to print "all manner of books".
Thus began the press's tradition of publishing the Bible, a tradition that has endured for over four centuries, beginning with the Geneva Bible, continuing with the Authorized Version, the Revised Version, the New English Bible and the Revised English Bible. The restrictions and compromises forced upon Cambridge by the dispute with the London Stationers did not come to an end until the scholar Richard Bentley was given the power to set up a'new-style press' in 1696. In July 1697 the Duke of Somerset made a loan of £200 to the university "towards the printing house and presse" and James Halman, Registrary of the University, lent £100 for the same purpose, it was in Bentley's time, in 1698, that a body of senior scholars was appointed to be responsible to the university for the press's affairs. The Press Syndicate's publishing committee still meets and its role still includes the review and approval of the press's planned output. John Baskerville became University Printer in the mid-eighteenth century.
Baskerville's concern was the production of the finest possible books using his own type-design and printing techniques. Baskerville wrote, "The importance of the work demands all my attention. Caxton would have found nothing to surprise him if he had walked into the press's printing house in the eighteenth century: all the type was still being set by hand. A technological breakthrough was badly needed, it came when Lord Stanhope perfected the making of stereotype plates; this involved making a mould of the whole surface of a page of type and casting plates from that mould. The press was the first to use this technique, in 1805 produced the technically successful and much-reprinted Cambridge Stereotype Bible. By the 1850s the press was using steam-powered machine presses, employing two to three hundred people, occupying several buildings in the Silver Street and Mill Lane area, including the one that the press still occupies, the Pitt Building, built for the press and in honour of William Pitt the Younger.
Under the stewardship of C. J. Clay, University Printer from 1854 to 1882, the press increased the size and scale of its academic and educational publishing operation. An important factor in this increase was the inauguration of its list of schoolbooks. During Clay's administration, the press undertook a sizeable co-publishing venture with Oxford: the Revised Version of the Bible, begun in 1870 and completed in 1885, it was in this period as well that the Syndics of the press turned down what became the Oxford English Dictionary—a proposal for, brought to Cambridge by James Murray before he turned to Oxford. The appointment of R. T. Wright as Secretary of the Press Syndicate in 1892 marked the beginning of the press's development as a modern publishing business with a defined editorial policy and administrative structure, it was Wright who devised the plan for one of the most distinctive Cambridge contributions to publishing—the Cambridge Histories. The Cambridge Modern History was published
Fracture (mineralogy)
In the field of mineralogy, fracture is the texture and shape of a rock's surface formed when a mineral is fractured. Minerals have a distinctive fracture, making it a principal feature used in their identification. Fracture differs from cleavage in that the latter involves clean splitting along the cleavage planes of the mineral's crystal structure, as opposed to more general breakage. All minerals exhibit fracture, but when strong cleavage is present, it can be difficult to see. Conchoidal fracture breakage that resembles the concentric ripples of a mussel shell, it occurs in amorphous or fine-grained minerals such as flint, opal or obsidian, but may occur in crystalline minerals such as quartz. Subconchoidal fracture is similar to with less significant curvature. Earthy fracture is reminiscent of freshly broken soil, it is seen in soft, loosely bound minerals, such as limonite and aluminite. Hackly fracture is jagged and not even, it occurs when metals are torn, so is encountered in native metals such as copper and silver.
Splintery fracture comprises sharp elongated points. It is seen in fibrous minerals such as chrysotile, but may occur in non-fibrous minerals such as kyanite. Uneven fracture is a rough one with random irregularities, it occurs in a wide range of minerals including arsenopyrite and magnetite. Rudolf Duda and Lubos Rejl: Minerals of the World http://www.galleries.com/minerals/property/fracture.htm
Crystal
A crystal or crystalline solid is a solid material whose constituents are arranged in a ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations; the scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification; the word crystal derives from the Ancient Greek word κρύσταλλος, meaning both "ice" and "rock crystal", from κρύος, "icy cold, frost". Examples of large crystals include snowflakes and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Examples of polycrystals include most metals, rocks and ice. A third category of solids is amorphous solids, where the atoms have no periodic structure whatsoever.
Examples of amorphous solids include glass and many plastics. Despite the name, lead crystal, crystal glass, related products are not crystals, but rather types of glass, i.e. amorphous solids. Crystals are used in pseudoscientific practices such as crystal therapy, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements; the scientific definition of a "crystal" is based on the microscopic arrangement of atoms inside it, called the crystal structure. A crystal is a solid where the atoms form a periodic arrangement.. Not all solids are crystals. For example, when liquid water starts freezing, the phase change begins with small ice crystals that grow until they fuse, forming a polycrystalline structure. In the final block of ice, each of the small crystals is a true crystal with a periodic arrangement of atoms, but the whole polycrystal does not have a periodic arrangement of atoms, because the periodic pattern is broken at the grain boundaries.
Most macroscopic inorganic solids are polycrystalline, including all metals, ice, etc. Solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids called glassy, vitreous, or noncrystalline; these have no periodic order microscopically. There are distinct differences between crystalline solids and amorphous solids: most notably, the process of forming a glass does not release the latent heat of fusion, but forming a crystal does. A crystal structure is characterized by its unit cell, a small imaginary box containing one or more atoms in a specific spatial arrangement; the unit cells are stacked in three-dimensional space to form the crystal. The symmetry of a crystal is constrained by the requirement that the unit cells stack with no gaps. There are 219 possible crystal symmetries, called crystallographic space groups; these are grouped into 7 crystal systems, such as hexagonal crystal system. Crystals are recognized by their shape, consisting of flat faces with sharp angles.
These shape characteristics are not necessary for a crystal—a crystal is scientifically defined by its microscopic atomic arrangement, not its macroscopic shape—but the characteristic macroscopic shape is present and easy to see. Euhedral crystals are those with well-formed flat faces. Anhedral crystals do not because the crystal is one grain in a polycrystalline solid; the flat faces of a euhedral crystal are oriented in a specific way relative to the underlying atomic arrangement of the crystal: they are planes of low Miller index. This occurs; as a crystal grows, new atoms attach to the rougher and less stable parts of the surface, but less to the flat, stable surfaces. Therefore, the flat surfaces tend to grow larger and smoother, until the whole crystal surface consists of these plane surfaces. One of the oldest techniques in the science of crystallography consists of measuring the three-dimensional orientations of the faces of a crystal, using them to infer the underlying crystal symmetry.
A crystal's habit is its visible external shape. This is determined by the crystal structure, the specific crystal chemistry and bonding, the conditions under which the crystal formed. By volume and weight, the largest concentrations of crystals in the Earth are part of its solid bedrock. Crystals found in rocks range in size from a fraction of a millimetre to several centimetres across, although exceptionally large crystals are found; as of 1999, the world's largest known occurring crystal is a crystal of beryl from Malakialina, Madagascar, 18 m long and 3.5 m in diameter, weighing 380,000 kg. Some crystals have formed by magmatic and metamorphic processes, giving origin to large masses of crystalline rock; the vast majority of igneous rocks are formed from molten magma and the degree of crystallization depends on the conditions under which they solidified. Such rocks as granite, which have cooled slowly and under great pressures, have crystallized.
Switzerland
Switzerland the Swiss Confederation, is a country situated in western and southern Europe. It consists of 26 cantons, the city of Bern is the seat of the federal authorities; the sovereign state is a federal republic bordered by Italy to the south, France to the west, Germany to the north, Austria and Liechtenstein to the east. Switzerland is a landlocked country geographically divided between the Alps, the Swiss Plateau and the Jura, spanning a total area of 41,285 km2. While the Alps occupy the greater part of the territory, the Swiss population of 8.5 million people is concentrated on the plateau, where the largest cities are to be found: among them are the two global cities and economic centres Zürich and Geneva. The establishment of the Old Swiss Confederacy dates to the late medieval period, resulting from a series of military successes against Austria and Burgundy. Swiss independence from the Holy Roman Empire was formally recognized in the Peace of Westphalia in 1648; the country has a history of armed neutrality going back to the Reformation.
It pursues an active foreign policy and is involved in peace-building processes around the world. In addition to being the birthplace of the Red Cross, Switzerland is home to numerous international organisations, including the second largest UN office. On the European level, it is a founding member of the European Free Trade Association, but notably not part of the European Union, the European Economic Area or the Eurozone. However, it participates in the Schengen Area and the European Single Market through bilateral treaties. Spanning the intersection of Germanic and Romance Europe, Switzerland comprises four main linguistic and cultural regions: German, French and Romansh. Although the majority of the population are German-speaking, Swiss national identity is rooted in a common historical background, shared values such as federalism and direct democracy, Alpine symbolism. Due to its linguistic diversity, Switzerland is known by a variety of native names: Schweiz. On coins and stamps, the Latin name – shortened to "Helvetia" – is used instead of the four national languages.
Switzerland is one of the most developed countries in the world, with the highest nominal wealth per adult and the eighth-highest per capita gross domestic product according to the IMF. Switzerland ranks at or near the top globally in several metrics of national performance, including government transparency, civil liberties, quality of life, economic competitiveness and human development. Zürich and Basel have all three been ranked among the top ten cities in the world in terms of quality of life, with the first ranked second globally, according to Mercer in 2018; the English name Switzerland is a compound containing Switzer, an obsolete term for the Swiss, in use during the 16th to 19th centuries. The English adjective Swiss is a loan from French Suisse in use since the 16th century; the name Switzer is from the Alemannic Schwiizer, in origin an inhabitant of Schwyz and its associated territory, one of the Waldstätten cantons which formed the nucleus of the Old Swiss Confederacy. The Swiss began to adopt the name for themselves after the Swabian War of 1499, used alongside the term for "Confederates", used since the 14th century.
The data code for Switzerland, CH, is derived from Latin Confoederatio Helvetica. The toponym Schwyz itself was first attested in 972, as Old High German Suittes perhaps related to swedan ‘to burn’, referring to the area of forest, burned and cleared to build; the name was extended to the area dominated by the canton, after the Swabian War of 1499 came to be used for the entire Confederation. The Swiss German name of the country, Schwiiz, is homophonous to that of the canton and the settlement, but distinguished by the use of the definite article; the Latin name Confoederatio Helvetica was neologized and introduced after the formation of the federal state in 1848, harking back to the Napoleonic Helvetic Republic, appearing on coins from 1879, inscribed on the Federal Palace in 1902 and after 1948 used in the official seal.. Helvetica is derived from the Helvetii, a Gaulish tribe living on the Swiss plateau before the Roman era. Helvetia appears as a national personification of the Swiss confederacy in the 17th century with a 1672 play by Johann Caspar Weissenbach.
Switzerland has existed as a state in its present form since the adoption of the Swiss Federal Constitution in 1848. The precursors of Switzerland established a protective alliance at the end of the 13th century, forming a loose confederation of states which persisted for centuries; the oldest traces of hominid existence in Switzerland date back about 150,000 years. The oldest known farming settlements in Switzerland, which were found at Gächlingen, have been dated to around 5300 BC; the earliest known cultural tribes of the area were members of the Hallstatt and La Tène cultures, named after the archaeological site of La Tène on the north side of Lake Neuchâtel. La Tène culture developed and flourished during the late Iron Age from around 450 BC under some influence from the Gree
Pleochroism
Pleochroism is an optical phenomenon in which a substance has different colors when observed at different angles with polarized light. Anisotropic crystals will have optical properties; the direction of the electric field determines the polarization of light, crystals will respond in different ways if this angle is changed. These kinds of crystals have two optical axes. If absorption of light varies with the angle relative to the optical axis in a crystal pleochroism results. Anisotropic crystals have double refraction of light where light of different polarizations is bent different amounts by the crystal, therefore follows different paths through the crystal; the components of a divided light beam follow different paths within the mineral and travel at different speeds. When the mineral is observed at some angle, light following some combination of paths and polarizations will be present, each of which will have had light of different colors absorbed. At another angle, the light passing through the crystal will be composed of another combination of light paths and polarizations, each with their own color.
The light passing through the mineral will therefore have different colors when it is viewed from different angles, making the stone seem to be of different colors. Tetragonal and hexagonal minerals can only show two colors and are called dichroic. Orthorhombic and triclinic crystals can show three and are trichroic. For example, which has two optical axes, can have a red, yellow, or blue appearance when oriented in three different ways in three-dimensional space. Isometric minerals cannot exhibit pleochroism. Tourmaline is notable for exhibiting strong pleochroism. Gems are sometimes cut and set either to display pleochroism or to hide it, depending on the colors and their attractiveness; the pleochroic colors are at their maximum when light is polarized parallel with a principle optical vector. The axes are designated X, Y, Z for direction, alpha and gamma in magnitude of the refractive index; these axes can be determined from the appearance of a crystal in a conoscopic interference pattern. Where there are two optical axes, the acute bisectrix of the axes gives Z for positive minerals and X for negative minerals and the obtuse bisectrix gives the alternative axis.
Perpendicular to these is the Y axis. The color is measured with the polarization parallel to each direction. An absorption formula records the amount of absorption parallel to each axis in the form of X < Y < Z with the left most having the least absorption and the rightmost the most. Pleochroism is an useful tool in mineralogy and gemology for mineral and gem identification, since the number of colors visible from different angles can identify the possible crystalline structure of a gemstone or mineral and therefore help to classify it. Minerals that are otherwise similar have different pleochroic color schemes. In such cases, a thin section of the mineral is used and examined under polarized transmitted light with a petrographic microscope. Another device using this property to identify minerals is the dichroscope. Amethyst: different shades of purple Andalusite: green-brown / dark red / purple Beryl: purple / colorless Corundum: purple / orange Hypersthene: purple / orange Spodumene: purple / clear / pink Tourmaline: pale purple / purple Putnisite: pale purple / bluish grey Aquamarine: clear / light blue, or light blue / dark blue Alexandrite: dark red-purple / orange / green Apatite: blue-yellow / blue-colorless Benitoite: colorless / dark blue Cordierite: pale yellow / violet / pale blue Corundum: dark violet-blue / light blue-green Tanzanite See Zoisite Topaz: colorless / pale blue / pink Tourmaline: dark blue / light blue Zoisite: blue / red-purple / yellow-green Zircon: blue / clear / gray Alexandrite: dark red / orange / green Andalusite: brown-green / dark red Corundum: green / yellow-green Emerald: green / blue-green Peridot: yellow-green / green / colorless Titanite: brown-green / blue-green Tourmaline: blue-green / brown-green / yellow-green Zircon: greenish brown / green Kornerupine: green / pale yellowish-brown / reddish-brown Hiddenite: blue-green / emerald-green / yellow-green Citrine: different shades of pale yellow Chrysoberyl: red-yellow / yellow-green / green Corundum: yellow / pale yellow Danburite: pale yellow / pale yellow Orthoclase: different shades of pale yellow Phenacite: colorless / yellow-orange Spodumene: different shades of pale yellow Topaz: tan / yellow / yellow-orange Tourmaline: pale yellow / dark yellow Zircon: tan / yellow Hornblende: light green / dark green / yellow / brown Corundum: yellow-brown / orange Topaz: brown-yellow / dull brown-yellow Tourmaline: dark brown / light brown Zircon: brown-red / brown-yellow Biotite: brown Alexandrite: dark red / orange / green Andalusite: dark red / brown-red Corundum: violet-red / orange-red Morganite: light red / red-violet Tourmaline: dark red / light red Zircon: purple / red-brown Birefringence Medieval sunstone
Gneiss
Gneiss is a common and distributed type of metamorphic rock. Gneiss is formed by high temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Orthogneiss is gneiss derived from igneous rock. Paragneiss is gneiss derived from sedimentary rock. Gneiss forms at higher pressures than schist. Gneiss nearly always shows a banded texture characterized by alternating darker and lighter colored bands and without a distinct foliation; the word gneiss has been used in English since at least 1757. It is borrowed from the German word Gneis also spelled Gneiss, derived from the Middle High German noun gneist "spark". Gneiss is formed from sedimentary or igneous rock exposed to temperatures greater than 320°C and high pressure. Gneissic rocks are medium- to coarse-foliated. Gneisses that are metamorphosed igneous rocks or their equivalent are termed granite gneisses, diorite gneisses, etc. Gneiss rocks may be named after a characteristic component such as garnet gneiss, biotite gneiss, albite gneiss, etc.
Orthogneiss designates a gneiss derived from an igneous rock, paragneiss is one from a sedimentary rock. Gneissose rocks have properties similar to gneiss. Gneiss appears to be striped in bands like parallel lines in shape, called gneissic banding; the banding is developed under high pressure conditions. The minerals are arranged into layers; the appearance of layers, called'compositional banding', occurs because the layers, or bands, are of different composition. The darker bands have more mafic minerals; the lighter bands contain more felsic minerals. A common cause of the banding is the subjection of the protolith to extreme shearing force, a sliding force similar to the pushing of the top of a deck of cards in one direction, the bottom of the deck in the other direction; these forces stretch out the rock like a plastic, the original material is spread out into sheets. Some banding is formed from original rock material, subjected to extreme temperature and pressure and is composed of alternating layers of sandstone and shale, metamorphosed into bands of quartzite and mica.
Another cause of banding is "metamorphic differentiation", which separates different materials into different layers through chemical reactions, a process not understood. Not all gneiss rocks have detectable banding. In kyanite gneiss, crystals of kyanite appear as random clumps in what is a plagioclase matrix. Augen gneiss, from the German: Augen, meaning "eyes", is a coarse-grained gneiss resulting from metamorphism of granite, which contains characteristic elliptic or lenticular shear-bound feldspar porphyroclasts microcline, within the layering of the quartz and magnetite bands. Henderson gneiss is found in South Carolina, US, east of the Brevard Shear Zone, it has deformed into two sequential forms. The second, more warped, form is associated with the Brevard Fault, the first deformation results from displacement to the southwest. Most of the Outer Hebrides of Scotland have a bedrock formed from Lewisian gneiss. In addition to the Outer Hebrides, they form basement deposits on the Scottish mainland west of the Moine Thrust and on the islands of Coll and Tiree.
These rocks are igneous in origin, mixed with metamorphosed marble and mica schist with intrusions of basaltic dikes and granite magma. Gneisses of Archean and Proterozoic age occur in the Baltic Shield. List of rock types Blatt and Robert J. Tracy. Petrology: Igneous and Metamorphic, 2nd ed. Freeman, pp. 359–65. ISBN 0-7167-2438-3. Gillen, Con. Geology and landscapes of Scotland. Harpenden. Terra Publishing. ISBN 1-903544-09-2. Harper, Douglas. "gneiss", Online Etymological Dictionary. Retrieved 2015-03-01. Marshak, Stephen. Essentials of Geology. W. W. Norton. ISBN 978-0-393-91939-4. McKirdy, Roger Crofts and John Gordon. Land of Mountain and Flood: The Geology and Landforms of Scotland. Edinburgh. Birlinn. ISBN 978-1-84158-357-0. Murray, W. H.. The Hebrides. London. Heinemann. Sacks, Paul E. and Donald T. Secor. "Kinematics of Late Paleozoic continental collision between Laurentia and Gondwana". Science, 250: 1702–05. Doi:10.1126/science.250.4988.1702. "Gneiss". Encyclopædia Britannica. 1911. "Gneiss". New International Encyclopedia.
1906
Oxide minerals
The oxide mineral class includes those minerals in which the oxide anion is bonded to one or more metal ions. The hydroxide-bearing minerals are included in the oxide class; the minerals with complex anion groups such as the silicates, sulfates and phosphates are classed separately. Simple oxides: X2O and XO Cuprite Cu2O Ice H2O Periclase group Periclase MgO Manganosite MnO Zincite group Zincite ZnO Bromellite BeO Tenorite CuO Litharge PbO X2O3Hematite group Corundum Al2O3 Hematite Fe2O3 Ilmenite FeTiO3 XO2Rutile group Rutile TiO2 Pyrolusite MnO2 Cassiterite SnO2 Baddeleyite ZrO2 Uraninite UO2 Thorianite ThO2 XY2O4Spinel group Spinel MgAl2O4 Gahnite ZnAl2O4 Magnetite Fe3O4 Franklinite 2O4 Chromite FeCr2O4 Chrysoberyl BeAl2O4 Columbite2O6Hydroxide subgroup: Brucite Mg2 Manganite MnO Romanechite BaMn2+Mn4+8O164 Goethite group Diaspore αAlO Goethite αFeO IMA-CNMNC proposes a new hierarchical scheme; this list uses it to modify the Classification of Nickel–Strunz. Abbreviations: "*" - discredited.
"?" - questionable/doubtful. "REE" - Rare-earth element "PGE" - Platinum-group element 03. C Aluminofluorides, 06 Borates, 08 Vanadates, 09 Silicates: Neso: insular Soro: grouping Cyclo: ring Ino: chain Phyllo: sheet Tekto: three-dimensional framework Nickel–Strunz code scheme: NN. XY.##x NN: Nickel–Strunz mineral class number X: Nickel–Strunz mineral division letter Y: Nickel–Strunz mineral family letter ##x: Nickel–Strunz mineral/group number, x add-on letter 04. A Metal:Oxygen = 2.1 and 1:1 04. AA Cation:Anion = 2:1: 05 Ice, 10 Cuprite, 15 Paramelaconite 04. AB M:O = 1:1. AC M:O = 1:1. B Metal:Oxygen = 3:4 and similar 04. BA With small and medium-sized cations: 05 Chrysoberyl, 10 Manganostibite 04. BB With only medium-sized cations: 05 Filipstadite, 05 Donathite?, 05 Gahnite, 05 Galaxite, 05 Hercynite, 05 Spinel, 05 Cochromite, 05 Chromite, 05 Magnesiochromite, 05 Manganochromite, 05 Nichromite, 05 Zincochromite, 05 Magnetite, 05 Cuprospinel, 05 Franklinite, 05 Jacobsite, 05 Magnesioferrite, 05 Trevorite, 05 Brunogeierite, 05 Coulsonite, 05 Magnesiocoulsonite, 05 Qandilite, 05 Ulvospinel, 05 Vuorelainenite.
BC With medium-sized and large cations: 05 Marokite, 10 Dmitryivanovite 04. BD With only large cations: 05 Minium 04. C Metal:Oxygen = 2:3, 3:5, Similar 04. CB With medium-sized cations: 05 Tistarite, 05 Auroantimonate*, 05 Brizziite-VII, 05 Brizziite-III, 05 Corundum, 05 Eskolaite, 05 Hematite, 05 Karelianite, 05 Geikielite, 05 Ecandrewsite, 05 Ilmenite, 05 Pyrophanite, 05 Melanostibite, 05 Romanite*. CC With large and medium-sized cations: 05 Chrombismite, 10 Freudenbergite, 15 Grossite, 20 Mayenite, 25 Yafsoanite. D Metal:Oxygen = 1:2 and similar 04. DA With small cations 04. DB With medium-sized cations. DC With medium-sized cations. DD With medium-sized cations. DE With medium-sized cations.
One or more of the preceding sentences incorporates text from a publication now in the public domain: Spencer, Leonard James (1911). . In Chisholm, Hugh (ed.). Encyclopædia Britannica. 1 (11th ed.). Cambridge University Press. pp. 919–920.
One or more of the preceding sentences incorporates text from a publication now in the