|
Hans Heinrich Landolt
Hans Heinrich Landolt (5 December 1831 – 15 March 1910) was a Swiss chemist who discovered iodine clock reaction. He is also one of the founders of Landolt–Börnstein database. He tested law of mass conservation which was given by Lavoisier. Biography Landolt was born in Zurich and at the age of nineteen entered the university there to study chemistry and physics. He attended the lectures of Carl Jacob Löwig and published his first work on stibmethyl in ''Schriften der Naturforschenden Gesellschaft'' (Writings of the Natural Science Society). He was then appointed assistant to Lowig and followed him in 1853 to Breslau. The same year he obtained the degree of Doctor of Philosophy with a thesis "Ueber die Arsenäthyle" (On ethyl compounds of arsenic) which was a notable contribution to the law of chemical valence. After the defense, he went to Berlin to attend lectures of Eilhard Mitscherlich, Rose, Johannes Muller and Dubois. Facilities for experimental research in chemistry we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Konrad Beilstein
Friedrich Konrad Beilstein (russian: Фёдор Фёдорович Бейльштейн) (17 February 183818 October 1906), was a Russian chemist and founder of the famous ''Handbuch der organischen Chemie'' (''Handbook of Organic Chemistry''). The first edition of this work, published in 1881, covered 1,500 compounds in 2,200 pages. This handbook is now known as the Beilstein database. Life Beilstein was born in Saint Petersburg in a family of German descent. Although he mastered the Russian language, he was educated in a German school. At the age of 15, he left for the University of Heidelberg where he studied chemistry under the tuition of Robert Bunsen. After two years he moved to the University of Munich and became a pupil of Justus Liebig, but soon returned to Heidelberg. There he acquired an interest and preference for organic chemistry, which became his major. For his Ph.D., Beilstein joined Friedrich Wöhler at the University of Göttingen, receiving his doctorate in Febr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiss Chemists
Swiss may refer to: * the adjectival form of Switzerland *Swiss people Places *Swiss, Missouri * Swiss, North Carolina *Swiss, West Virginia *Swiss, Wisconsin Other uses *Swiss-system tournament, in various games and sports *Swiss International Air Lines **Swiss Global Air Lines, a subsidiary *Swissair, former national air line of Switzerland *.swiss alternative TLD for Switzerland See also *Swiss made, label for Swiss products *Swiss cheese (other) *Switzerland (other) *Languages of Switzerland, none of which are called "Swiss" *International Typographic Style, also known as Swiss Style, in graphic design *Schweizer (other), meaning Swiss in German *Schweitzer, a family name meaning Swiss in German *Swisse Swisse is a vitamin, supplement, and skincare brand. Founded in Australia in 1969 and globally headquartered in Melbourne, and was sold to Health & Happiness, a Chinese company based in Hong Kong previously known as Biostime International, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1910 Deaths
Year 191 ( CXCI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Apronianus and Bradua (or, less frequently, year 944 ''Ab urbe condita''). The denomination 191 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Parthia * King Vologases IV of Parthia dies after a 44-year reign, and is succeeded by his son Vologases V. China * A coalition of Chinese warlords from the east of Hangu Pass launches a punitive campaign against the warlord Dong Zhuo, who seized control of the central government in 189, and held the figurehead Emperor Xian Emperor Xian of Han (2 April 181 – 21 April 234), personal name Liu Xie (劉協), courtesy name Bohe, was the 14th and last emperor of the Eastern Han dynasty in China. He reigned from 28 September 189 until 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1831 Births
Events January–March * January 1 – William Lloyd Garrison begins publishing '' The Liberator'', an anti-slavery newspaper, in Boston, Massachusetts. * January 10 – Japanese department store, Takashimaya in Kyoto established. * February–March – Revolts in Modena, Parma and the Papal States are put down by Austrian troops. * February 2 – Pope Gregory XVI succeeds Pope Pius VIII, as the 254th pope. * February 5 – Dutch naval lieutenant Jan van Speyk blows up his own gunboat in Antwerp rather than strike his colours on the demand of supporters of the Belgian Revolution. * February 7 – The Belgian Constitution of 1831 is approved by the National Congress. *February 8 - Aimé Bonpland leaves Paraguay. * February 14 – Battle of Debre Abbay: Ras Marye of Yejju marches into Tigray, and defeats and kills the warlord Sabagadis. * February 25 – Battle of Olszynka Grochowska (Grochów): Polish rebel forces divide a Ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berichte Der Deutschen Chemischen Gesellschaft
''Chemische Berichte'' (usually abbreviated as ''Ber.'' or ''Chem. Ber.'') was a German-language scientific journal of all disciplines of chemistry founded in 1868. It was one of the oldest scientific journals in chemistry, until it merged with ''Recueil des Travaux Chimiques des Pays-Bas'' to form ''Chemische Berichte/Recueil'' in 1997. ''Chemische Berichte/Recueil'' was then merged with other European journals in 1998 to form ''European Journal of Inorganic Chemistry''. History Founded in 1868 as ''Berichte der Deutschen Chemischen Gesellschaft'' (, CODEN BDCGAS), it operated under this title until 1928 (Vol. 61). The journal was then split into: * ''Berichte der Deutschen Chemischen Gesellschaft, A: Vereins-Nachrichten'' (, CODEN BDCAAS), and * ''Berichte der Deutschen Chemischen Gesellschaft, B: Abhandlungen'' (, CODEN BDCBAD). Vol. 78 and 79 (1945–1946) were omitted and not published due to World War II. The journal was renamed ''Chemische Berichte'' (, CODEN CHBEAM) in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfurous Acid
Sulfurous acid (also sulfuric(IV) acid, sulphurous acid (UK), sulphuric(IV) acid (UK)) is the chemical compound with the formula . There is no evidence that sulfurous acid exists in solution, but the molecule has been detected in the gas phase. The conjugate bases of this elusive acid are, however, common anions, bisulfite (or hydrogen sulfite) and sulfite. Sulfurous acid is an intermediate species in the formation of acid rain from sulfur dioxide. Raman spectra of solutions of sulfur dioxide in water show only signals due to the molecule and the bisulfite ion, . The intensities of the signals are consistent with the following equilibrium: 17O NMR spectroscopy provided evidence that solutions of sulfurous acid and protonated sulfites contain a mixture of isomers, which is in equilibrium: Attempts to concentrate the solutions of sulfurous acid simply reverses the equilibrium, producing sulfur dioxde and water vapor. A clathrate with the formul a has been crystallised. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine Clock - Persulphate
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compoun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Meyerhoffer
Wilhelm Meyerhoffer (13 September 1864 – 21 April 1906) was a German chemist. Meyerhoffer studied chemistry and worked with Jacobus Henricus van 't Hoff at the University of Amsterdam and the University of Berlin. The mineral Meyerhofferite Meyerhofferite is a hydrated borate mineral of calcium, with the chemical formula Ca2B6O6(OH)10·2H2O, CaB3O3(OH)5·H2O or Ca2(H3B3O7)2·4H2O. It occurs principally as an alteration product of inyoite, another borate mineral. Natural meyerhoffer ... is named after him. References * 1864 births 1906 deaths 19th-century German chemists {{Germany-chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Börnstein
Richard Börnstein (9 January 1852 – 13 May 1913) was a German physicist and meteorologist. Born into a Jewish family in Königsberg, he studied natural sciences at the University of Göttingen, and later on, worked as an assistant to Georg Hermann Quincke at the University of Heidelberg. In 1877 he obtained his habilitation at Heidelberg, and afterwards taught classes in experimental physics and meteorology at the Agricultural Academy in Proskau. From 1881 onward, he served as a professor at the Agricultural University of Berlin.Börnstein, Richard Leopold, Meteorologe In (NDB). Band 2, Duncker & Humblot, Berlin 1955, , . At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Rotation
Optical rotation, also known as polarization rotation or circular birefringence, is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Circular birefringence and circular dichroism are the manifestations of optical activity. Optical activity occurs only in chiral materials, those lacking microscopic mirror symmetry. Unlike other sources of birefringence which alter a beam's state of polarization, optical activity can be observed in fluids. This can include gases or solutions of chiral molecules such as sugars, molecules with helical secondary structure such as some proteins, and also chiral liquid crystals. It can also be observed in chiral solids such as certain crystals with a rotation between adjacent crystal planes (such as quartz) or metamaterials. When looking at the source of light, the rotation of the plane of polarization may be either to the right (dextrorotator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aachen
Aachen ( ; ; Aachen dialect: ''Oche'' ; French and traditional English: Aix-la-Chapelle; or ''Aquisgranum''; nl, Aken ; Polish: Akwizgran) is, with around 249,000 inhabitants, the 13th-largest city in North Rhine-Westphalia, and the 28th-largest city of Germany. It is the westernmost city in Germany, and borders Belgium and the Netherlands to the west, the triborder area. It is located between Maastricht (NL) and Liège (BE) in the west, and Bonn and Cologne in the east. The Wurm River flows through the city, and together with Mönchengladbach, Aachen is the only larger German city in the drainage basin of the Meuse. Aachen is the seat of the City Region Aachen (german: link=yes, Städteregion Aachen). Aachen developed from a Roman settlement and (bath complex), subsequently becoming the preferred medieval Imperial residence of Emperor Charlemagne of the Frankish Empire, and, from 936 to 1531, the place where 31 Holy Roman Emperors were crowned Kings of the Germans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Optical Rotation")
