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Phlogiston
The phlogiston theory is a superseded scientific theory that postulated the existence of a fire-like element called phlogiston () contained within combustible bodies and released during combustion. The name comes from the Ancient Greek (''burning up''), from (''flame''). The idea was first proposed in 1667 by Johann Joachim Becher and later put together more formally by Georg Ernst Stahl. Phlogiston theory attempted to explain chemical processes such as combustion and rusting, now collectively known as oxidation. It was challenged by the concomitant weight increase, and was abandoned before the end of the 18th century following experiments by Antoine Lavoisier and others. Phlogiston theory led to experiments which ultimately concluded with the discovery of oxygen. Theory Phlogiston theory states that ''phlogisticated'' substances contain phlogiston and that they ''dephlogisticate'' when burned, releasing stored phlogiston which is absorbed by the air. Growing plants then ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antoine Lavoisier
Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794), CNRS ( Centre National de la Recherche Scientifique) also Antoine Lavoisier after the , was a and who was central to the 18th-century [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Priestley
Joseph Priestley (; 24 March 1733 – 6 February 1804) was an English chemist, natural philosopher, separatist theologian, grammarian, multi-subject educator, and liberal political theorist. He published over 150 works, and conducted experiments in electricity and other areas of science. He was a close friend of, and worked in close association with Benjamin Franklin involving electricity experiments. Priestley is credited with his independent discovery of oxygen by the thermal decomposition of mercuric oxide, having isolated it in 1774. During his lifetime, Priestley's considerable scientific reputation rested on his invention of carbonated water, his writings on electricity, and his discovery of several "airs" (gases), the most famous being what Priestley dubbed "dephlogisticated air" (oxygen). Priestley's determination to defend phlogiston theory and to reject what would become the chemical revolution eventually left him isolated within the scientific community. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Ernst Stahl
Georg Ernst Stahl (22 October 1659 – 24 May 1734) was a German chemist, physician and philosopher. He was a supporter of vitalism, and until the late 18th century his works on phlogiston were accepted as an explanation for chemical processes.Ku-ming Chang (2008)"Stahl, Georg Ernst", ''Complete Dictionary of Scientific Biography'', Vol. 24, from Cengage Learning __TOC__ Biography Georg Ernst Stahl was born on October 22, 1659, at Anspach in Bavaria. Raised as a son to a Lutheran Pastor, he was brought up in a very pious and religious household. From an early age he expressed profound interest toward chemistry, even by age 15 mastering a set of university lecture notes on chemistry and eventually a difficult treatise by Johann Kunckel. He had two wives, who both died from puerperal fever in 1696 and 1706. He also had a son Johnathan and a daughter who died in 1708. He continued to work and publish following the death of both of his wives and eventually his children, but was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superseded Scientific Theories
This list catalogs well-accepted theories in science and pre-scientific natural philosophy and natural history which have since been superseded by scientific theories. Many discarded explanations were once supported by a scientific consensus, but replaced after more empirical information became available that identified flaws and prompted new theories which better explain the available data. Pre-modern explanations originated before the scientific method, with varying degrees of empirical support. Some theories are discarded in their entirety, such as the replacement of the phlogiston theory by energy and thermodynamics. Some theories known to be incomplete or in some ways incorrect are still used. For example, Newtonian classical mechanics is accurate enough for practical calculations at everyday distances and velocities, and it is still taught in schools. The more complicated relativistic mechanics must be used for long distances and velocities nearing the speed of light, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Rutherford
Daniel Rutherford (3 November 1749 – 15 December 1819) was a Scottish physician, chemist and botanist who is known for the isolation of nitrogen in 1772. Life Rutherford was born on 3 November 1749, the son of Anne Mackay and Professor John Rutherford (1695–1779). He began college at the age of 16 at Mundell's School on the West Bow close to his family home, and then studied medicine under William Cullen and Joseph Black at the University of Edinburgh, graduating with a doctorate (MD) in 1772. From 1775 to 1786 he practiced as a physician in Edinburgh. In 1783 he was a joint founder of the Royal Society of Edinburgh. He was president of the Harveian Society in 1787. At this time he lived at Hyndford Close on the Royal Mile. He was a professor of botany at the University of Edinburgh and the 5th Regius Keeper of the Royal Botanic Garden Edinburgh from 1786 to 1819. He was president of the Royal College of Physicians of Edinburgh from 1796 to 1798. His pupils included ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Juncker
Johann Juncker (23 December 1679 in Londorf, Hesse – 25 October 1759 in Halle) was a German physician and chemist. Juncker was a leader in the Pietist reform movement as it applied to medicine. He directed the Francke Foundations and initiated approaches to medical practice, charitable treatment, and education at the University of Halle that influenced others internationally. He was a staunch proponent of Georg Ernst Stahl and helped to more clearly present Stahl's phlogiston theory of combustion. Early life and education Johann Juncker was born on 23 December 1679 to Johann Ludwig Juncker, a well-to-do tenant farmer in Londorf, near Giessen. Juncker went to school in Allendorf and Obernhof, before attending the Pädagogium in Giessen for four years. The head of the institution at that time, J. H. May, was a Pietist. A dissident evangelical reform movement, Pietism emphasized the practical application of theology and active charitable work. Juncker attended the University o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calx
Calx is a substance formed from an ore or mineral that has been heated. Calx, especially of a metal, is now known as an oxide. According to the obsolete phlogiston theory, the calx was the true elemental substance, having lost its phlogiston in the process of combustion. "Calx" is also sometimes used in older texts on artist's techniques to mean calcium oxide. Etymology Calx is Latin for chalk or limestone, from the Greek χάλιξ (''khaliks'', “pebble”). It is not to be confused with the Latin homonym meaning heelbone (or calcaneus in modern medical Latin), which has an entirely separate derivation. In popular culture * UK electronic music artist Aphex Twin Richard David James (born 18 August 1971), best known as Aphex Twin, is an Irish-born British musician, composer and DJ. He is known for his idiosyncratic work in electronic styles such as techno, ambient, and jungle. Journalists from publication ... named four of his tracks after differently coloured calxes (g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giovanni Antonio Giobert
Giovanni Antonio Giobert also known as Jean-Antoine Giobert (27 October 1761 in Mongardino - 14 September 1834 in Millefiori) was an Italian chemist and mineralogist who studied magnetism, galvanism, and agricultural chemistry. He introduced Antoine Lavoisier's theories to Italy, and built a phosphorus-based eudiometer sufficiently sensitive to measure atmospheric carbon dioxide and oxygen. He identified the correct composition of the mineral Gioberite, a form of magnesite (MgCO3) found in the Piedmont area. He was made a knight (Cavaliere) for his work on the chemistry of indigo dyes. Early life Giovanni Antonio Giobert was born on 27 October 1761 in Mongardino near Asti, to Spirito and Anna Gugalin. He was educated by Abbot G. B. Lovizzolo, studying the physical sciences and chemistry, and was apprenticed in pharmacies in Asti and Turin. Science In his early twenties, Giobert focused his studies on the application of chemistry in agriculture and industry. He became a member of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Heinrich Pott
Johann Heinrich Pott (6 October 1692 – 29 March 1777) was a Prussian physician and chemist. He is considered a pioneer of pyrochemistry. He examined the elements bismuth and manganese apart from attempting improvements to glass and porcelain production. Biography Pott was born in Halberstadt, son of the royal councillor Johann Andreas Pott (1662–1729) and Dorothea Sophia daughter of Andreas Machenau. He studied at the cathedral school in Halberstadt and Francke's pedagogium before studying theology at the University of Halle. He then shifted to study medicine and chemistry under Georg Ernst Stahl. In 1713 he studied assaying at Mansfield under mining master Lages. He spent two years along with two of his brothers as travelling evangelists for the Community of True Inspiration but he left the sect in 1715 and returned to study chemistry at Halle, receiving a doctorate in 1716 on sulfur under Friedrich Hoffmann. He worked as a physician in Halberstadt before moving to Berlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many industrially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver Of Sulphur
Liver of sulfur is a loosely defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and likely potassium bisulfide. Synonyms include hepar sulfuris, sulfur, sulfurated potash and sulfurated potassa. There are two distinct varieties: "potassic liver of sulfur" and "ammoniacal liver of sulfur". Overview Liver of sulfur is mainly used in metalworking to form a brown or black patina on copper and silver as well as many (though not all) copper alloys and silver alloys (brass, for example— a copper alloy— does not react with sulfur compounds). It is sold as a yellow brittle solid (a "lump" which must be mixed with water before use) as well as a pre-mixed liquid and a gel form. The solid is believed to have the longest shelf life, though all liver of sulfur tends to decompose with time. Modern gel forms contain stabilizers that allow the reactivity to last much longer. Liver of sulfur that is kept dry, sealed from air, out of the light, and in a free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
