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data/en.wikipedia.org/wiki/Edward_Loysel-0.md

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+---
+title: "Edward Loysel"
+chunk: 1/1
+source: "https://en.wikipedia.org/wiki/Edward_Loysel"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:00.976880+00:00"
+instance: "kb-cron"
+---
+
+Edward Loysel (Vannes, 1816 – 1865), born Édouard Loysel de La Lantais, was a French-British engineer who patented an early espresso machine, and is known for having coined and popularised the terms "percolator" and "percolation."
+Initially professor of mechanics and natural sciences in Marseille, France, he began to move into business in following years. In the early 1840s, he first patented an advertising panel and a chess game. 
+Later on, Loysel built over existing work undertaken by Jöns Jacob Berzelius in Sweden, the Count of Real and Pierre-François-Guillaume Boullay in France, and other techniques developed in Germany, to patent in 1845 his "Hydrostatic percolator" described as "devices, intended to obtain, by infusion, liquid extracts and various substances".
+Mainly used for coffee, the machine was exhibited at the 1855 Paris Exposition. As Loysel had moved to the UK in 1844 (and obtained British nationality in 1848), his machine was presented as part of the "English catalogue" of the world fair. In London, he was member of the Institution of Civil Engineers.
+The success of Loysel's machine was also ensured by its capacity to produce hundreds of cups of coffee per hour.
+
+
+== References ==

data/en.wikipedia.org/wiki/Ethnochemistry-0.md

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+---
+title: "Ethnochemistry"
+chunk: 1/1
+source: "https://en.wikipedia.org/wiki/Ethnochemistry"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:02.233858+00:00"
+instance: "kb-cron"
+---
+
+Ethnochemistry is the study of chemical ideas found in any culture; where an appreciation of cultural heritage is preserved.  In the West African country of Ghana, an example of this are the bead makers who do not explain what they're doing in modern chemical terms, though they do explain the process in their own artistic way.  A similar concept is ethnomathematics; Achor, et al. concluded that there was a positive impact on the achievement of students and retention of knowledge when ethnomathematics is applied to a classroom setting, it can also help to make students aware of the role in which chemistry plays in their everyday lives.
+
+
+== References ==

data/en.wikipedia.org/wiki/Etymology_of_chemistry-0.md

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+---
+title: "Etymology of chemistry"
+chunk: 1/1
+source: "https://en.wikipedia.org/wiki/Etymology_of_chemistry"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:03.486347+00:00"
+instance: "kb-cron"
+---
+
+The word chemistry derives from the word alchemy, which is found in various forms in European languages.
+The word alchemy itself derives from the Arabic word al-kīmiyāʾ (الكيمياء), wherein al- is the definite article 'the'. The ultimate origin of the word is uncertain, but the Arabic term kīmiyāʾ (كيمياء) is likely derived from either the Ancient Greek word khēmeia (χημεία) or the similar khēmia (χημία).
+The Greek term khēmeia, meaning 'cast together', may refer to the art of alloying metals, from root words χύμα (khúma, 'fluid') and χέω (khéō, 'I pour'). Alternatively, khēmia may be derived from the ancient Egyptian name of Egypt, khem, khm, khame, or khmi, meaning 'blackness', likely in reference to the rich dark soil of the Nile river valley.
+
+
+== Overview ==
+There are two main views on the derivation of the Greek word. According to one, the word comes from the greek χημεία (chimeía, meaning 'pouring' or 'infusion'), used in connection with the study of the juices of plants, and thence extended to chemical manipulations in general; this derivation accounts for the old-fashioned spellings chymist and chymistry. The other view traces it to khem or khame, hieroglyph khmi, which denotes black earth as opposed to barren sand, and was used by Plutarch as χημία (chimía); on this derivation, the word alchemy is explained as meaning 'the Egyptian art'. The first occurrence of the word is said to be in a treatise of Julius Firmicus, an astrological writer of the 4th century, but the prefix al- must be the addition of a later Arabic copyist. In English, works by Piers Plowman (1362) use the phrase experimentis of alconomye, with variants alkenemye and alknamye. The prefix al- began to be dropped about the middle of the 16th century.
+
+
+=== Egyptian origin ===
+According to the Egyptologist Wallis Budge, the Arabic word al-kīmiyaʾ actually means 'the Egyptian [science]', borrowing from the Coptic word for "Egypt", kēme (or its equivalent in the Medieval Bohairic dialect of Coptic, khēme). This Coptic word derives from Demotic kmỉ, itself from ancient Egyptian kmt. The ancient Egyptian word referred to both the country and the colour black (Egypt was the "Black Land", by contrast with the "Red Land", the surrounding desert); so this etymology could also explain the nickname "Egyptian black arts". However, according to Friedrich Mahn, this theory may be an example of folk etymology. Assuming an Egyptian origin, chemistry is defined as follows:
+
+Chemistry, from the ancient Egyptian word "khēmia" meaning transmutation of earth, is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals.
+Thus, according to Budge and others, chemistry derives from the Egyptian word khemein or khēmia, meaning the 'preparation of black powder', ultimately derived from the name khem (Egypt). A decree of Diocletian, written about AD 300 in Greek, speaks against "the ancient writings of the Egyptians, which treat of the khēmia transmutation of gold and silver".
+
+
+=== Greek origin ===
+Arabic al-kīmiyaʾ or al-khīmiyaʾ (الكيمياء or الخيمياء), according to some, is thought to derive from the Koine Greek word khymeia (χυμεία) meaning 'the art of alloying metals' or 'alchemy'; in the manuscripts, this word is also written as khēmeia (χημεία) or kheimeia (χειμεία), which is the probable basis of the Arabic form. According to Mahn, the Greek word χυμεία (khumeia) originally meant "cast together", "casting together", "weld", "alloy", etc. (cf. Gk. kheein (χέειν) "to pour"; khuma (χύμα), "that which is poured out, an ingot"). Assuming a Greek origin, chemistry is defined as follows:
+
+Chemistry, from the Greek word χημεία (khēmeia) meaning "cast together" or "pour together", is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals.
+
+
+== From alchemy to chemistry ==
+Later Medieval Latin had alchimia/alchymia ('alchemy'), alchimicus ('alchemical'), and alchimista ('alchemist'). The 16th century mineralogist and humanist Georg Agricola was the first to drop the Arabic definite article al-. In his Latin works from 1530 onwards, he exclusively wrote chymia and chymista in describing activity that we today would characterize as chemical or alchemical. As a humanist, Agricola was intent on purifying words and returning them to their classical roots. He had no intent to make a semantic distinction between chymia and alchymia.
+In the late 16th century, Agricola's newly coined terminology gradually came into use. It seems to have been adopted in most of the vernacular European languages following Conrad Gessner's adoption of it in his widely circulated pseudonymous work, Thesaurus Euonymi Philiatri De remediis secretis: Liber physicus, medicus, et partim etiam chymicus (Zurich, 1552). Gessner's work was frequently re-published in the second half of the 16th century in Latin and was also published in a number of vernacular European languages, with the word spelled without the al-.
+In the 16th and 17th centuries in Europe, the forms alchimia, chimia and chymia were synonymous and interchangeable. The semantic distinction between a rational and practical science of chimia and an occult alchimia arose only in the early eighteenth century.
+In English of the 16th, 17th, and early 18th centuries, both the forms with and without the prefix al- were commonly spelled with i or y, as in chymic, chymic, alchimic, and alchymic. During the later 18th century, the spelling was re-fashioned to use the letter e, as in chemic in English. In English, after the spelling shifted from chimical to chemical, there was a corresponding shift from alchimical to alchemical, which occurred in the early 19th century. In French, Italian, Spanish and Russian today, it continues to be spelled with an i as in, for example, Italian chimica.
+
+
+== See also ==
+History of chemistry
+History of science
+History of thermodynamics
+List of Arabic loanwords in English
+List of chemical element name etymologies
+
+
+== Notes ==
+
+
+== References ==

data/en.wikipedia.org/wiki/Factitious_airs-0.md

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+---
+title: "Factitious airs"
+chunk: 1/3
+source: "https://en.wikipedia.org/wiki/Factitious_airs"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:04.801665+00:00"
+instance: "kb-cron"
+---
+
+Factitious airs is an archaic term for synthetic gases coined by Robert Boyle around 1670 .
+
+== Background ==
+Factitious airs (also factitious air or artificial airs) was a term used in 17th- to early 19th-century pneumatic chemistry for any gas, then called an "elastic fluid", that could be artificially produced from solid or liquid bodies by chemical reaction, fermentation, putrefaction, distillation, dissolution, or heat. The phrase was coined by Robert Boyle around 1670 while isolating what is now recognized as hydrogen (which he termed "inflammable air").
+The term was rigorously defined by Henry Cavendish in his landmark 1766 paper Three papers, containing experiments on factitious air. Cavendish described factitious air as "any kind of air which is contained in other bodies in an unelastic state, and is produced from thence by art". At the time, these gases were understood to be distinct from ordinary atmospheric air and were rarely obtained in pure form; archaic nomenclature was therefore inconsistent and often applied overlapping or mistaken labels to the same substance.
+The study of factitious airs encompassed what are now known as hydrogen ("inflammable air"), carbon dioxide ("fixed air" or "fixible air"), ammonia ("alkaline air" or "volatile alkali"), oxygen ("dephlogisticated air", "vital air", or "oxygene"), nitrous oxide ("dephlogisticated nitrous air"), nitric oxide ("nitrous air"), carbon monoxide ("hydrocarbonate" or "water gas"), methane ("marsh gas" or "carburetted hydrogen"), hydrogen sulfide ("hepatic air"), and several others. These investigations were central to the development of pneumatic chemistry, the refinement and eventual overthrow of phlogiston theory, and the Chemical Revolution led by Antoine Lavoisier. The same body of work also laid the foundation for pneumatic medicine, most notably through the efforts of Thomas Beddoes and James Watt at the Pneumatic Institution in the 1790s, where factitious airs were trialed as treatments for tuberculosis and other conditions.
+With the widespread acceptance of Lavoisier’s oxygen theory and the new chemical nomenclature in the late 1780s and 1790s, the archaic term "factitious airs" gradually fell out of use.
+
+== Definition ==
+Factitious means "artificial, not natural", so the term means "man-made gases".
+An archaic definition from 1747  for the production of factitious air was defined as being caused by: "1- by flow Degrees from Putrefactions and Fermentations of all Kinds; or 2- more expeditiously by some Sorts of chymical Dissolutions of Bodies; or 3- and lastly, almost instantaneously by the Explosion of Gunpowder, and the Mixture or some Kinds of Bodies. Thus, if Paste or Dough with Leaven be placed in an exhausted Receiver, it will, after some Time, by Fermentation, produce a considerable quantity of Air, which will appear very plainly by the Sinking the Quicksilver in the Gage. Thus also any Animal or Vegetable Substance, putrifying in Vacuo, will produce the same Effect."
+
+== Therapeutics ==
+The study of these airs interfaced with phlogiston theory.
+The therapeutic potential of factitious airs were widely investigated with significant contributions by Thomas Beddoes, James Watt, James Lind, Humphry Davy, Robert John Thornton, and others at the Pneumatic Institution. Georgiana Cavendish, Duchess of Devonshire (related to Henry through marriage) had a profound interest in chemistry with interest in Henry's research in pneumatic chemistry. She played a pivotal role in advancing the study of factitious airs through partnering with Thomas Beddoes to establish the Pneumatic Institution.
+Tuberculosis was a primary disease physicians had attempted to treat with factitious airs, particularly since James Watt's daughter died of the disease. John Carmichael had reported successfully treating a patient suffering from tuberculosis using hydrocarbonate. This application of factitious air was pioneering research relevant to the modern era as carbon monoxide currently has preclinical evidence of treating Mycobacterium tuberculosis infection progression by inducing dormancy, stimulating host immune response, and ameliorating host inflammation.
+
+== Historical Names ==
+There are significant inconsistencies in the ancient nomenclature due to the limited knowledge of chemistry and primitive analytical technology of the era (i.e. based on the chemistry, it is clear the terms were mistakenly assigned to more than one gas by different investigators). Furthermore, in most cases the gases were not pure. Historical names used for factitious airs may have included:
+
+=== Ammonia ===
+Gaseous ammonia was first isolated by Joseph Black in 1756 by reacting sal ammoniac (ammonium chloride) with calcined magnesia (magnesium oxide). It was isolated again by Peter Woulfe in 1767, by Carl Wilhelm Scheele in 1770 . In 1785, Claude Louis Berthollet ascertained its composition.
+
+ammoniac
+"the volatile alkali in its pure state"
+alkaline air
+Term used by Joseph Priestley in 1773 upon isolation of ammonia.
+Other historical names: gaseous ammonia, azoturetted hydrogen, volatile alkali, ammonical gas
+
+=== Carbon Dioxide ===
+
+==== Fixed Air ====
+Fixed air, or fixible air, is an ancient term for carbon dioxide
+Joseph Priestley credited Joseph Black for discovering and coining "fixed air", which was thought to exist in a fixed state in alkaline salts, chalk, and other calcareous substances. Black considered substances containing fixed air to be "mild", and upon expulsion of the gas by heating the resulting state is "caustic" by corroding or burning plants and animals (e.g. CO2 released by chalk upon decomposition to calcium oxide). In other words, the fixed air (also known as fixible air) was thought to be fixated within a corrosive molecule.
+Priestley likewise credited the discovery of fixed air to contributions from several scientists including: David Macbride, John Pringle, William Brownrigg (regarded carbonated water to have an acidulous taste), Stephen Hales, and many others.
+Henry Cavendish provided a definition: "By fixed air, I mean that particular species of factitious air, which is separated from alkaline substances by solution in acids or by calcination". Cavendish essentially defined potassium oxide or calcium oxide as a base, which can contain a fixated air within its composition, setting the stage for the historical definition of carbonate.

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+---
+title: "Factitious airs"
+chunk: 2/3
+source: "https://en.wikipedia.org/wiki/Factitious_airs"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:04.801665+00:00"
+instance: "kb-cron"
+---
+
+==== Carbonic Acid ====
+According to Claude Louis Berthollet, "What has long been called fixed, or fixible air, being really an acid in the state of gas, has of late received several new denominations. It has been called aerial acid, as existing very readily in the state of air, or more properly of gas, and plentifully in the atmosphere. The chalky acid, as procurable in large quantities from chalk, or other mild calcareous substances. The name given to it in this essay is derived from the knowledge of its composition, as lately ascertained by the French Chemists to consist of the elementary part of charcoal, named charbone, or char, united with oxygen, or the acidifying principle. Hence it is called, with strict propriety, carbonic acid in general; carbonic acid gas when in the aerial form; and carbonic acid liquor when combined with or dissolved in water."
+By French Chemists, Berthollet is generally referring to Lavoisier's oxidation discoveries. The name oxygen is derived from Greek with oxy meaning acid, and gene to mean forming/expression, therefore carbonic acid is simply the union of carbon with oxygen (Laviosier's original degrees of oxidation could not fit the concept of carbon monoxide as it was based on diamond, graphite, coal and carbonic acid)
+The 1804 definition by John Sadler of the Pneumatic Institution is, "A peculiar elastic fluid possessed of acid properties, formerly called fixed air, produced when charcoal or diamond is burned in oxygene; its is carbon perfectly oxygenated. It contains carbon 1, oxygene 4.
+
+===== Carbonic acid gas =====
+Carbonic acid gas was an ancient term to specify the gaseous state of carbonic acid (i.e. the term is synonymous and interchangeable with carbonic acid despite explicitly describing the gaseous state). It is listed as an alternative name for carbon dioxide in PubChem. In 1796 externally applied carbonic acid gas to the epidermis was reported to treat breast cancer; and inhalation treated tuberculosis and other indications. Henry Hill Hickman evaluated carbonic acid gas (produced by mixing sulfuric acid with carbonate of lime) for a surgical anesthetic.
+
+==== Carbonate ====
+Carbonate was defined as "a compound formed by the union of carbonic acid with an earth, alkali, or metallic oxide [...] they are distinguished by the property of effervescing on the addition of an acid" The definition expands upon fixed air being fixated within carbonate to suggest carbonic acid is a constituent of carbonate, therefore in the ancient language the suffix "-ic acid" and "-ate" were not interchangeable.
+The modern definition is similar, although equipped with the molecular knowledge of carbonate's structure and reassignment of the meaning of carbonic acid from CO2 to the H2CO3 molecule, "Carbonates are the salts of carbonic acids. They form when a positively charged metal ion comes into contact with the oxygen atoms of the carbonate ion." 
+
+==== Bicarbonate ====
+Bicarbonate, originally known as bi-carbonate of potash, was coined by William Hyde Wollaston in 1814 based on hydrocarbonate's potential to release two molar equivalents of carbon dioxide (referred to as carbonic acid at the time) as released by both potassium hydrocarbonate (initially known as carbonate of potash, suggested to become bicarbonate) and potassium carbonate (vaguely known as subcarbonate, suggested to become carbonate) upon formation of potash (potassium oxide).
+Bicarbonates have historically been defined as, "combinations of the bases with the carbonic acid, in which two atoms of the latter are united to one of the former" In other words, potash (potassium oxide) was well-understood to be a caustic base and essentially the core molecule that subsequent chemical nomenclature was built upon. Carbonate of potash (potassium carbonate) must contain a carbonic acid species fixated within potash's alternative composition (see fixed air above). Since "bi-carbonate of potash" liberates a double dose of carbonic acid, to distinguish between the similar substances, the prefix bi- indicates the bi-carbonate of potash (potassium hydrocarbonate) contains twice as much CO2 fixated in this form potash's composition relative to the carbonate of potash. The same ancient logic (prior to the understanding of molecular formulas and reaction stoichiometry) applied to soda, carbonate of soda, and bicarbonate of soda.
+The word saleratus, from Latin sal æratus (meaning "aerated salt"), was widely used beginning in the 1840s.
+
+==== Miscellaneous historical names ====
+gas silvestre
+Ancient origin for fixed air by Jan Baptist van Helmont
+gas produced from fermenting and effervescing substances.
+Other historical names: Spiritus sylvestris, vinous gas, calcareous gas, aerial acid, acid of air, luft-saeure, carbonic anhydride, Gas acide carbonique, Gas carbonicum, chalky acid, acid of chalk, kriedesaeure, kohlensaeures gas, choke-damp, cretaceous acid, Acide mephitique, Mephitic air, deutoxide of carbon
+
+=== Carbon monoxide ===
+
+hydrocarbonate
+Water gas prepared by passing steam over charcoal/coke. Alternatively prepared from unspecified alcohol and sulphuric acid.
+Hydrocarbonate was recognized to brighten venous blood and compete with oxygen around 1796, although credit is widely awarded to Claude Bernard's work in the mid-1850s.
+carbonic oxide / protoxide
+William Cruickshank discovered the composition of carbon monoxide and named it gaseous oxide of carbon. Cruickshank recognized water and hydrogen were not a constituent of the combustible base which contained the same ingredients as carbonic acid, although containing less oxygen.
+Carbonic oxide was identified in the intestine of cattle in the 1800s, marking a trace origin for endogenous carbon monoxide.
+John Sadler's 1804 definition reads, "An inflammable elastic fluid, obtained by the action of ignited charcoal on some of the metallic oxides. It is carbon in its second degree of oxygenation, consisting of carbon 9, oxygen 21"
+carbonous oxyd
+The name carbonous oxyd relative to carbonic acid was once considered analogous to nitrous oxide to nitric acid based on the oxide not having sufficient oxygen to form the acid.
+Other historical names: gaseous oxide of carbon, hydrocarbonous acid, heavy inflammable air, carbonated hydrogene, oxycarburetted hydrogen (water gas)
+
+=== Hydrogen ===
+Hydrogen was initially thought to be toxic based on experiments by Lavoisier, however, the purity of the hydrogen was taken into question when later experiments discovered hydrogen to effectively treat measles in the 1790s.

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+---
+title: "Factitious airs"
+chunk: 3/3
+source: "https://en.wikipedia.org/wiki/Factitious_airs"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:04.801665+00:00"
+instance: "kb-cron"
+---
+
+factitious air (Boyle)
+hydro-gene
+means "water former" from hydro- and gene-
+hydrogene gas
+Inflammable air; a very light elastic fluid, produced by the action of water on ignited iron or zinc.
+Other historical names: inflammable air, inflammable gas, base of inflammable air, zincic inflammable air, martial inflammable air
+
+=== Hydrogen sulfide ===
+sulphurated hydrogene
+therapeutic application of hydrogen sulfide for gastrointestinal disorders dates as early as 1806
+Other historical names: hepatic air, hydrogenated sulfur
+
+=== Hydrogen disulfide ===
+supersulphuretted hydrogene
+
+=== Sulfur dioxide ===
+Vitriolic acid gas
+
+=== Methane ===
+marsh gas / marsh air
+Other historical names: carburetted hydrogen, light carburetted hydrogen, heavy inflammable air, dicarburet of hydrogen, fire-damp, gas of the acetates
+
+=== Nitrogen ===
+azot, or azotic air. Azote – means lifeless, or a-zote for "not life", generally regarded as the solid constituent whereas azotic gas was the gaseous form.
+Other historical names: phlogisticated air, atmospherical memphitic gas, mephitis, nitrogene, base of mephitis, stickstoffgas,
+
+=== Nitric oxide ===
+nitrous gas
+
+=== Nitrous oxide ===
+factitious air (Davy)
+Other historical names: dephlogisticated nitrous air, protoxide of nitrogen, hypo-nitrous oxide, gaseous oxide of azote, nitrous oxide,
+
+=== Nitrogen dioxide ===
+nitrous acid gas
+
+=== Oxygen ===
+Blood has been understood to absorb and deliver oxygen since the mid-1790s. Oxy-gene means acid-former or acid-expression, once thought all acids contained oxygen.
+
+oxygene gas
+An elastic fluid, constituting that part of the air of the atmosphere necessary for combustion and animal life. It is the supposed principle of acidity of the French chemists.
+Other historical names: vital air, highly respirable air, pure air, phosoxygen, dephlogisticated air, empyreal air, base of vital air,
+
+=== Miscellaneous ===
+animal inflammable air
+Phosphane / Phosphine
+Phosphotetted Hydrogene
+hydrochloric acid
+marine acid gas
+chlorine gas
+dephlogisticated marine acid gas
+fulmination gases
+
+== References ==

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+---
+title: "Faraday Society"
+chunk: 1/1
+source: "https://en.wikipedia.org/wiki/Faraday_Society"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:06.037565+00:00"
+instance: "kb-cron"
+---
+
+The Faraday Society was a British society for the study of physical chemistry, founded in 1903 and named in honour of Michael Faraday. In 1980, it merged with several similar organisations, including the Chemical Society, the Royal Institute of Chemistry, and the Society for Analytical Chemistry to form the Royal Society of Chemistry which is both a learned society and a professional body.  At that time, the Faraday Division became one of six units within the Royal Society of Chemistry.
+The Faraday Society published Faraday Transactions from 1905 to 1971, when the Royal Society of Chemistry took over the publication.
+Of particular note were the conferences called Faraday Discussions, which were published under the same name. The publication includes the discussion of the paper as well as the paper itself. At the meeting, more time is given to the discussion than to the author presenting the paper as the audience are given the papers prior to the meeting. These conferences continue to be run by the Royal Society of Chemistry.
+In addition to its presidents, key figures at the Faraday Society included George Stanley Withers Marlow, Secretary and Editor of the society from 1926 to 1948,
+and his successor Frederick Clifford Tompkins. Tompkins served as Editor until 1977, and as the President of the Faraday Division of the amalgamated Royal Society of Chemistry from 1978 to 1979.
+Prior to the amalgamation, Tompkins received valuable assistance from D. A. Young, who became Editor as of 1977.
+
+
+== Presidents ==
+Sir Joseph Swan: 1903–1904
+Lord Kelvin: 1905–1907
+Sir William Henry Perkin: 1907
+Sir Oliver Lodge: 1908–1909
+Sir James Swinburne: 1909–1911
+Sir Richard T. Glazebrook: 1911–1913
+Sir Robert Abbott Hadfield: 1913–1920
+Professor Alfred W Porter: 1920–1922
+Sir Robert Robertson: 1922–1924
+Sir Frederick George Donnan: 1924–1926
+Professor Cecil Henry Desch: 1926–1928
+Professor Thomas Martin Lowry: 1928–1930
+Sir Robert Mond: 1930–1932
+Professor Nevil Vincent Sidgwick: 1932–1934
+William Rintoul: 1934–1936
+Professor Morris William Travers: 1936–1938
+Sir Eric Keightley Rideal: 1938–1945
+Professor William Edward Garner: 1945–1947
+Professor Arthur John Allmand: 1947–1948
+Sir John Lennard-Jones: 1948–1950
+Sir Charles Goodeve: 1950–1952
+Sir Hugh Taylor: 1952–1953
+Professor Ronald George Wreyford Norrish: 1953–1955
+Ronald Percy Bell: 1956–1957
+Sir Harry Work Melville: 1958
+Dr Edgar William Steacie: 1959
+Sir Harry Work Melville: 1960
+Sir Cyril Norman Hinshelwood: 1961–1962
+Professor Alfred Rene Ubbelhode: 1963–1964
+Sir Frederick Sydney Dainton: 1965–1966
+Professor Cecil Bawn: 1967–1968
+Professor Geoffrey Gee: 1969–1970
+Professor John Wilfrid Linnett: 1971–1972
+
+
+== See also ==
+Marlow Award
+
+
+== References ==

data/en.wikipedia.org/wiki/Fire_air-0.md

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+---
+title: "Fire air"
+chunk: 1/1
+source: "https://en.wikipedia.org/wiki/Fire_air"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:07.359657+00:00"
+instance: "kb-cron"
+---
+
+In the history of chemistry, fire air was postulated to be one of two fluids of common air.  This theory was positioned in 1775 by Swedish chemist Carl Wilhelm Scheele.[1]  In Scheele's Chemical Treatise on Air and Fire he states: "air is composed of two fluids, differing from each other, the one of which does not manifest in the least the property of attracting phlogiston, whilst the other, which composes between the third and fourth part of the whole mass of the air, is peculiarly disposed to such attraction." These two constituents of common air Scheele called Foul Air ("verdorbene Luft") and Fire Air ("Feuerluft"); afterwards these components came to be known as nitrogen and oxygen, respectively.
+
+
+== See also ==
+Heat
+
+
+== References ==

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+---
+title: "History of ESPCI Paris"
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+
+The history of the École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI ParisTech) began in 1882, driven by concerns among French chemical industry leaders about France's lag behind Germany, particularly after the annexation of Mulhouse following the Franco-Prussian War of 1870. Founded as the École Municipale de Physique et de Chimie Industrielles (EMPCI), later becoming ESPCI, the institution emerged during a period of weakness in French science, largely due to an underdeveloped university system. To counter Germany's economic and industrial strength, particularly in its chemical industry, Alsatian scientists drew inspiration from the German model of integrating higher education and research with industry, exemplified by the laboratories of Justus von Liebig.
+The history of ESPCI reflects the close interplay between science and industry in the late 19th and early 20th centuries, followed by a shift toward pure science in the 20th century, free from immediate economic demands. The institution’s evolution can be divided into two phases: an initial focus on industrial and economic needs, followed by a pivot toward fundamental research. Nonetheless, ESPCI has maintained a strong tradition of industry engagement. As Pierre-Gilles de Gennes and his successors emphasized, the school strives to blend cutting-edge fundamental research with practical applications.
+ESPCI has been home to notable French scientists, including several Nobel Prize laureates: Pierre Curie, Marie Curie, Pierre-Gilles de Gennes, and Georges Charpak. Its history sheds light on the context of major discoveries, such as the Curies' discovery of radium, and challenges the notion of a stark divide between science and industry.
+
+== Historical context of the establishment ==
+
+=== Institutional context ===
+
+The establishment of ESPCI was part of a broader effort to structure French higher education in the 19th century, initiated during the revolutionary period with the abolition of universities by the National Convention, and the creation of institutions like the Conservatoire national des arts et métiers (CNAM), École Polytechnique, and École normale supérieure. Located initially at 42 rue Lhomond, ESPCI was founded to address the chemical industry’s needs, which the shortcomings of the 1870s French higher education system failed to meet. This gap threatened France’s economic development amid Europe’s race toward industrialization, particularly in competition with Germany.
+French higher education in the 19th century was distinct from its European counterparts due to its dual structure: relatively inactive university faculties until 1870, and specialized institutions like the grandes écoles and research bodies such as the Collège de France and French Academy of Sciences. As historian Antoine Prost notes, true scientific education was provided at institutions like École Polytechnique, the Muséum national d'histoire naturelle, or the Collège de France, rather than in university faculties. These faculties, established by an 1808 decree, primarily focused on administering the baccalauréat, with little emphasis on research.
+Scientific and technical education was delivered through a diverse array of grandes écoles, some predating the French Revolution, such as the École nationale des ponts et chaussées (1747) and the École des Mines (1783). Post-1789 institutions included École spéciale militaire de Saint-Cyr (1802), École centrale Paris (1829), and various Écoles nationales supérieures d'arts et métiers. The core of French scientific training, however, rested with École Polytechnique and École normale supérieure, both founded in 1794.
+Under Charles Dupin’s influence, the CNAM offered free public education in applied sciences, including mechanics, chemistry for industrial applications, and industrial economics, as mandated by an 1819 ordinance. In industrial regions like Amiens, Lille, Lyon, Mulhouse, and Rouen, learned societies provided evening courses in mechanics and industrial chemistry, led by figures like Jean Girardin and Frédéric Kuhlmann.
+The École nationale supérieure de chimie de Mulhouse, established in 1822 to train personnel for chemical processes, was a rare institution specializing in industrial chemistry until its annexation by Germany in 1871, prompting Alsatian refugees in Paris to advocate for a similar school in the capital.
+
+=== Economic and industrial context ===
+
+==== The Second Industrial Revolution ====
+ESPCI’s creation coincided with the rise of organic chemistry, a key driver of the Second Industrial Revolution in the late 19th century, alongside advancements in electricity and turbine technology. This period saw a growing alignment between science and industry, particularly in organic chemistry, which was revolutionized by William Henry Perkin’s accidental discovery of mauveine in 1856. This breakthrough spurred the development of synthetic chemistry, replacing natural products with synthetic alternatives, driven by rational applications of atomic theory and molecular representations.
+
+==== Challenges in French Science and Chemistry ====
+During this era of technological and scientific progress, French research faced significant challenges. Antoine Prost highlights the dire state of French science: libraries were underfunded, with the Paris law faculty receiving only 1,000 francs annually, and provincial science faculties limited to 1,800 francs for heating, lighting, and laboratories. No laboratories existed at the Paris Faculty of Sciences or the Museum. Research was further hampered by excessive centralization.
+French chemistry struggled with the slow adoption of atomism. Albin Haller, in a report for the Exposition Universelle (1900), noted the resistance to atomic theory in France, which hindered progress in organic chemistry. The outdated "system of equivalents," championed by Marcellin Berthelot, persisted in French education until the late 19th century.
+
+The French higher education system, disconnected from cutting-edge research, failed to meet the needs of emerging industries like chemistry and electricity, which required skilled engineers and technicians. While faculties provided outdated academic knowledge, grandes écoles adhered to a model suited to the First Industrial Revolution, focusing on mathematics and mechanics but neglecting chemistry. Chemistry education was often undervalued, with terms like "chemist" used derogatorily at institutions like École centrale Paris.
+
+==== Insufficient reforms ====

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+title: "History of ESPCI Paris"
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+
+Prominent scientists like Louis Pasteur, Marcellin Berthelot, Claude Bernard, and Ernest Renan decried the state of French science in the 1850s and 1860s. Renan, in 1867, attributed Prussia’s victory at Sadowa to German scientific prowess, contrasting it with French deficiencies. Reforms began in the 1870s, with the law of July 12, 1875, allowing independent higher education institutions, and increased funding for faculties between 1875 and 1885. The decree of July 25, 1885, granted faculties greater autonomy and the ability to receive donations.
+However, these measures fell short, particularly in chemistry, where the loss of Mulhouse’s chemistry school to Germany left a critical gap. The Paris Universal Exposition of 1878 highlighted France’s industrial lag, prompting Charles Lauth to propose the creation of a National Chemistry School in a report to the Minister of Commerce and Agriculture, laying the groundwork for ESPCI’s establishment.
+
+== Establishment of the school ==
+
+=== Influence of the Alsatian network and the German model ===
+The authorship of Charles Lauth’s 1878 proposal was no coincidence. As a prominent member of the Association française pour l'avancement des sciences (AFAS), alongside Charles Adolphe Wurtz, Charles Friedel, Albin Haller, and Paul Schützenberger, Lauth shared a vision of science, its practice, and its relationship with industry, inspired by the German model. These five scientists formed the core of what historians Danielle Fauque and Georges Bram term the "Alsatian network."
+
+This group promoted the German model, credited for the success of the world’s leading chemical industry at the time, through the AFAS, which Wurtz and Friedel helped found. The AFAS’s annual congresses, held in different cities, effectively disseminated their ideas. For Lauth and his colleagues, Germany’s industrial success stemmed from strong ties between businesses, research, and education. Germany boasted a robust network of autonomous, well-funded universities offering high-level, accessible education. Professors were numerous, well-compensated, and respected, and applied sciences were embraced. Additionally, Germany’s technical schools, nearly all equipped with chemistry laboratories by 1892, trained the engineers the industry needed. The German system’s effectiveness was proven by Justus von Liebig, who, from 1825, emphasized precise laboratory techniques at his Giessen laboratory, a model for German universities and technical institutes led by his former students.
+Key features of the German model—decentralization, well-funded universities, accessible education, pragmatism, and a focus on applied research—were absent in France, to the dismay of the Alsatian network.
+
+=== Charles Lauth’s proposal for a national school ===
+By 1878, when Lauth wrote to the Minister of Commerce and Agriculture, French higher education reforms were underway. Lauth’s proposal emphasized the need for research and teaching laboratories to train students in “living” chemistry and an education system focused on industrial applications. He envisioned an autonomous chemistry school, a model already well-established.
+
+Lauth’s proposed curriculum spanned three years, combining theoretical lectures with practical laboratory work. The first year would cover qualitative and quantitative mineral analysis and basic preparations, with lectures on inorganic and organic chemistry. The second year would focus on organic analysis, industrial analyses, and complex preparations, with lectures on major chemical industries. The third year would train students to solve industrial problems through methodical projects, with lectures highlighting the latest scientific and industrial advancements. Graduates would earn a special “chemical engineer” diploma after an examination or competition. This approach, supported by figures like Louis Pasteur and Marcellin Berthelot, aimed to avoid the excessive abstraction of institutions like École Polytechnique and the rudimentary empiricism of schools like the École nationale supérieure d'arts et métiers. It emphasized experimental science and laboratory work to produce skilled chemical engineers capable of addressing the challenges of the emerging chemical industry.
+However, Lauth’s national school proposal was not realized, reportedly due to resistance from grandes écoles and Parisian academics offended by his critiques.
+
+=== Creation of the Municipal School in Paris ===
+
+Undeterred, Lauth turned to the Paris Municipal Council, where he served. On December 22, 1880, the council prioritized the school’s creation, allocating 10,000 francs for a feasibility study and forming a commission. On June 20, 1881, the Prefect of the Seine appointed 14 commission members, including Berthelot, Wurtz, and Lauth (as director of the Sèvres manufactory). The commission’s report, presented months later, outlined the school’s entrance requirements, internal regulations, study duration, curriculum, budget, and mission statement. Two innovations stood out: the inclusion of physics alongside chemistry, anticipating their mutual development, particularly in electricity, following the 1881 Paris International Electricity Exposition; and a 50-franc monthly stipend for students to broaden access, echoing the German model’s accessibility.
+The report’s mission statement emphasized the school’s goal: to equip students with specialized scientific knowledge for significant roles in industrial settings, such as constructing physics apparatus or conducting industrial chemistry research. Unlike existing higher education institutions, which trained doctors, pharmacists, professors, and scholars, the École Municipale de Physique et de Chimie Industrielle would complement advanced primary education, focusing on practical, specialized training to produce foremen, engineers, or chemists. It drew inspiration from similar schools in Mulhouse, Zurich, and Strasbourg, and referenced Lauth’s 1878 letter advocating for a national chemistry school.
+The École Municipale de Physique et de Chimie Industrielle was formally established by an ordinance signed by Prefect Charles Floquet on August 28, 1882.
+
+== Two major periods of the school ==
+The history of ESPCI, particularly its relationship with industry and research, can be divided into two distinct periods. The first, lasting until the late 1920s under Paul Langevin’s directorship, was marked by a strong industrial focus. The second, beginning in the early 1930s, saw a significant shift toward fundamental sciences and research.
+
+=== 1882–1930: A school in service of the industry ===
+
+==== Influence of the Alsatian network ====

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+
+The first three directors—Paul Schützenberger, Charles Lauth, and Albin Haller—were instrumental in the school’s founding, alongside Charles Friedel, an early board member, and Charles Adolphe Wurtz, who served on the municipal council’s study commission. The École Municipale de Physique et de Chimie Industrielle (EMPCI), later ESPCI, was deeply shaped by the ideas of the Alsatian network, comprising these five scientists.
+The school adopted the pragmatic German model championed by the Alsatian network, emphasizing practical and experimental training. The EMPCI curriculum allocated only a quarter of its time to theoretical courses, with the rest dedicated to industrially relevant activities: laboratory work, technical drawing, and technological problem-solving, with minimal lectures. Third-year students were introduced to industrial accounting, basic political economy, and discussions on manufacturing processes and industry needs. This reflected a strong commitment to industrial integration.
+The institution maintained close ties with industry. Industrialists comprised nearly one-sixth of the board, ensuring alignment with industrial strategies by assigning some courses to scientists employed in industry. Faculty members also engaged directly in industrial projects: Schützenberger contributed to chemical manufacturing, particularly fertilizers and synthetic dyes; Lauth collaborated with the Saint-Denis chemical company’s research and production teams; and Haller consulted extensively with Parisian industrialists.
+The student profile further reinforced the school’s industrial focus. Admission targeted graduates of advanced primary schools, equipped with practical skills in science and mathematics and inclined toward industrial careers, unlike lycée students, who showed little interest in technical fields, or those from basic primary schools, whose education was insufficient.
+
+==== Neglect of scientific research ====
+
+Despite the Alsatian network’s influence, the EMPCI diverged from Lauth’s original vision. Lauth criticized Parisian laboratories as inadequate for students seeking to learn, lacking proper guidance to translate scientific discoveries into practical outcomes or spark new industries. His proposed third-year curriculum aimed to train students in solving industrial problems while keeping them updated on scientific and industrial advancements. However, the EMPCI’s early curriculum prioritized technology over pure science, omitting the latest scientific developments, particularly in the third year, which focused on industrial accounting and economic discussions.
+Research, even applied, was absent from the curriculum, with no time allocated for it. Regulations discouraged personal research by preparators, requiring them to dedicate their time to supervising students in laboratories, where third-year students spent most of their day. Despite this, exceptions were made, notably allowing Pierre Curie to research piezoelectricity.
+
+==== Balancing Science and Industry ====
+
+The early directors sought to balance the school’s industrial mission with scientific research, though this was challenging. On November 5, 1906, Haller proposed hosting foreign researchers to enhance the school’s reputation, citing the international renown of its faculty. Lauth, then a board member, opposed this, arguing that the school’s industrial focus should not shift toward pure science, as hosting foreign researchers could compromise its purpose.
+Schützenberger also championed fundamental research. Paul Langevin noted that without Schützenberger’s and his successors’ support, Pierre Curie might not have completed his groundbreaking thesis on magnetism or discovered radium, potentially leaving the school. A 1903 evaluation of Curie acknowledged his tendency toward pure science but valued his contributions to the school’s prestige.
+This balancing act enabled high-level research, notably by Pierre and Marie Curie, but resources were limited. Terry Shinn notes that Pierre Curie, a mere lecturer, conducted his research in a dilapidated shed with outdated equipment.
+
+=== From 1930: Embracing research ===
+
+It was not until the early 1930s, under the leadership of Paul Langevin, that ESPCI began to fully embrace fundamental research and pure science.
+
+==== Nature of the changes ====
+Terry Shinn identifies four key changes to the curriculum: a) applied mathematics courses were replaced by advanced theoretical mathematics; b) technological training was partially overshadowed by theoretical sciences and the interplay between theory and experimental discoveries; c) specialized studies supplanted multidisciplinarity; and d) research became an integral part of the curriculum. The proportion of practical training decreased from 74% to 65% of study time, while theoretical instruction expanded. Concurrently, fundamental research gained prominence, exemplified by René Lucas’s work on birefringence and Georges Champetier’s contributions to molecular chemistry. ESPCI became a hub for discussing and refining bold concepts from Louis de Broglie and showcasing discoveries by Frédéric Joliot-Curie. Between 1953 and 1970, the number of active researchers at ESPCI grew from 37 to 116. A 1971 report emphasized that “research is inseparable from true higher education. How can one teach the science being created without participating in its creation?” In 1937, ESPCI relaxed its earlier restrictions, allowing foreign researchers from Luxembourg and Czechoslovakia, limited to 10% of the French student body. Meanwhile, industrial influence waned, with industrialists’ representation on the board halving to 10% between 1950 and 1965.
+
+==== Continued industrial connection ====
+The integration of research training, occupying 8% of the curriculum per Shinn’s analysis, and the emphasis on fundamental research marked a return to the principles of the Alsatian network. Yet, ESPCI retained its industrial mission. Industrialists, though fewer, remained on the board, and practical, application-oriented training continued to dominate the curriculum. Even the most fundamental research maintained a focus on practical applications, following the example of the Curies and Langevin, who applied his theoretical work on ultrasonics to invent sonar during World War I.
+
+Langevin and his successors rejected any strict divide between pure and applied science. Langevin argued that scientists must connect with society’s needs through engineers and technicians, stating: “The scientist can no longer remain isolated but must be linked to the farmer and the worker, increasingly educated, through a continuous chain of intermediaries and interpreters represented by engineers and technicians at various levels of expertise and roles. The need has become clear to ensure this connection by creating institutions to train individuals not only informed about established science but, above all, immersed in its methods, understanding through direct and sustained experimentation and rigorous laboratory training how science is created, its provisional and living nature, and the degree of confidence its results warrant, too often taught dogmatically, definitively, and lifelessly.” This ethos was deepened by successors like Pierre-Gilles de Gennes.

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+---
+title: "History of ESPCI Paris"
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+---
+
+=== The school today ===
+Under Pierre-Gilles de Gennes, ESPCI achieved its current balance, becoming one of France’s top engineering schools. De Gennes encouraged faculty to bridge science and industry, emphasizing the potential applications of even the most fundamental research.
+During his tenure, ESPCI expanded its fundamental research, hosting 20 laboratories, 18 affiliated with the CNRS, and two interdisciplinary research groups, collectively employing over 250 researchers and 40 foreign visitors. The school awards about 20 doctorates annually.
+ESPCI maintains strong industry ties, filing approximately 40 patents yearly. Several companies have emerged from the school. Claude Boccara, scientific director until 2003, noted: “The significant partnerships we maintain with public research entities (Ministry of Research, CNRS, Medical Research Institute) and private sectors (large corporations, small and medium enterprises) give ESPCI a distinctive profile of innovative research, seamlessly spanning the most fundamental aspects to the most strategic applications.”
+
+== Timeline ==
+
+== See also ==
+École supérieure de physique et de chimie industrielles de la ville de Paris
+Pierre Curie and Marie Curie
+Paul Langevin
+Pierre-Gilles de Gennes
+Georges Charpak
+Charles Adolphe Wurtz
+Charles Lauth
+Albin Haller
+Paul Schützenberger
+Charles Friedel
+Frédéric Joliot-Curie and Irène Joliot-Curie
+Justus von Liebig
+Second Industrial Revolution
+Organic chemistry
+
+== References ==
+
+== Bibliography ==
+Bensaude-Vincent, Bernadette (1987). Langevin: 1872-1946 ; science et vigilance [Langevin: 1872-1946; Science and Vigilance] (in French). Paris: Belin. ISBN 978-2-7011-0873-5.
+Biquard, Pierre (1982). Du radium au microprocesseur. Histoire de l'École Supérieure de Physique et de Chimie 1882-1982 [From Radium to the Microprocessor: History of the École Supérieure de Physique et de Chimie 1882-1982] (in French). Paris: Institut pour le Développement de la Science et de la Technologie. p. 169. ISBN 978-2903667016.
+Boudia, Soraya (1997). Marie Curie et son laboratoire : science, industrie, instruments et métrologie de la radioactivité en France. 1896-1941 [Marie Curie and Her Laboratory: Science, Industry, Instruments, and Metrology of Radioactivity in France, 1896-1941] (PhD dissertation). Université Paris VII - Denis Diderot. Retrieved May 23, 2025.
+Fauque, Danielle; Bram, Georges (1994). "Le réseau alsacien" [The Alsatian Network]. Bulletin de la société industrielle de Mulhouse (in French). 833: 17–20.
+Grelon, André (1989). "Les universités et la formation des ingénieurs en France (1870-1914)" [Universities and the Training of Engineers in France (1870-1914)]. Formation Emploi (in French). 27–28: 65–88. doi:10.3406/forem.1989.1354. Retrieved May 23, 2025.
+Grossetti, Michel (1996). Science, industrie et territoire [Science, Industry, and Territory] (in French). Toulouse: Presses Universitaires du Mirail. p. 312. doi:10.4000/books.pumi.13572. ISBN 978-2-85816-255-0.
+Prost, Antoine (1968). Histoire de l'enseignement en France, 1800-1967 [History of Education in France, 1800-1967] (in French). Paris: A. Colin. p. 523. ISBN 9782200310790.
+Ramunni, Girolamo (1995). Les sciences pour l'ingénieur. Histoire du rendez-vous des sciences et de la société [Sciences for the Engineer: History of the Convergence of Science and Society] (in French). Paris: Éditions du CNRS. p. 150. ISBN 9782271053732.
+Shinn, Terry (1981). "Des sciences industrielles aux sciences fondamentales. La mutation de l'École supérieure de physique et de chimie (1882-1970)" [From Industrial Sciences to Fundamental Sciences: The Transformation of the École supérieure de physique et de chimie (1882-1970)]. Revue Française de Sociologie. 22 (2): 167–182. doi:10.2307/3320999. JSTOR 3320999. Retrieved May 23, 2025.

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+title: "History of aluminium"
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+
+Aluminium (or aluminum) metal is very rare in native form, and the process to refine it from ores is complex, so for most of human history it was unknown. However, the compound alum has been known since the 5th century BCE and was used extensively by the ancients for dyeing. During the Middle Ages, its use for dyeing made it a commodity of international commerce. Renaissance scientists believed that alum was a salt of a new earth; during the Age of Enlightenment, it was established that this earth, alumina, was an oxide of a new metal. Discovery of this metal was announced in 1825 by Danish physicist Hans Christian Ørsted, whose work was extended by German chemist Friedrich Wöhler.
+Aluminium was difficult to refine and thus uncommon in actual use. Soon after its discovery, the price of aluminium exceeded that of gold. It was reduced only after the initiation of the first industrial production by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the Bayer process developed by Austrian chemist Carl Josef Bayer in 1889. These processes have been used for aluminium production up to the present.
+The introduction of these methods for the mass production of aluminium led to extensive use of the light, corrosion-resistant metal in industry and everyday life. Aluminium began to be used in engineering and construction. In World Wars I and II, aluminium was a crucial strategic resource for aviation. World production of the metal grew from 6,800 metric tons in 1900 to 2,810,000 metric tons in 1954, when aluminium became the most produced non-ferrous metal, surpassing copper.
+In the second half of the 20th century, aluminium gained usage in transportation and packaging. Aluminium production became a source of concern due to its effect on the environment, and aluminium recycling gained ground. The metal became an exchange commodity in the 1970s. Production began to shift from developed countries to developing ones; by 2010, China had accumulated an especially large share in both production and consumption of aluminium. World production continued to rise, reaching 58,500,000 metric tons in 2015. Aluminium production exceeds those of all other non-ferrous metals combined.
+
+== Early history ==
+"Today, I bring you the victory over the Turk. Every year they wring from the Christians more than three hundred thousand ducats for the alum with which we dye wool. For this is not found among the Latins except a very small quantity. [...] But I have found seven mountains so rich in this material that they could supply seven worlds. If you will give orders to engage workmen, build furnaces, and smelt the ore, you will provide all Europe with alum and the Turk will lose all his profits. Instead they will accrue to you ..." 
+
+The history of aluminium was shaped by the usage of its compound alum. The first written record of alum was in the 5th century BCE by Greek historian Herodotus. The ancients used it as a dyeing mordant, in medicine, in chemical milling, and as a fire-resistant coating for wood to protect fortresses from enemy arson. Aluminium metal was unknown. Roman writer Petronius mentioned in his novel Satyricon that an unusual glass had been presented to the emperor: after it was thrown on the pavement, it did not break but only deformed. It was returned to its former shape using a hammer. After learning from the inventor that nobody else knew how to produce this material, the emperor had the inventor executed so that it did not diminish the price of gold. Variations of this story were mentioned briefly in Natural History by Roman historian Pliny the Elder (who noted the story had "been current through frequent repetition rather than authentic") and Roman History by Roman historian Cassius Dio. Some sources suggest this glass could be aluminium. It is possible aluminium-containing alloys were produced in China during the reign of the first Jin dynasty (266–420).
+After the Crusades, alum was a commodity of international commerce; it was indispensable in the European fabric industry. Small alum mines were worked in Catholic Europe but most alum came from the Middle East. Alum continued to be traded through the Mediterranean Sea until the mid-15th century, when the Ottomans greatly increased export taxes. In a few years, alum was discovered in great abundance in Italy. Pope Pius II forbade all imports from the east, using the profits from the alum trade to start a war with the Ottomans. This newly found alum long played an important role in European pharmacy, but the high prices set by the papal government eventually made other states start their own production; large-scale alum mining came to other regions of Europe in the 16th century.
+
+== Establishing the nature of alum ==
+I think it not too venturesome to predict that a day will come when the metallic nature of the base of alum will be incontestably proven. 

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+title: "History of aluminium"
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+
+At the start of the Renaissance, the nature of alum remained unknown. Around 1530, Swiss physician Paracelsus recognized alum as separate from vitriole (sulfates) and suggested it was a salt of an earth. In 1595, German doctor and chemist Andreas Libavius demonstrated that alum and green and blue vitriole were formed by the same acid but different earths; for the undiscovered earth that formed alum, he proposed the name "alumina". German chemist Georg Ernst Stahl stated that the unknown base of alum was akin to lime or chalk in 1702; this mistaken view was shared by many scientists for half a century. In 1722, German chemist Friedrich Hoffmann suggested that the base of alum was a distinct earth. In 1728, French chemist Étienne Geoffroy Saint-Hilaire claimed alum was formed by an unknown earth and sulfuric acid; he mistakenly believed burning that earth yielded silica. (Geoffroy's mistake was corrected only in 1785 by German chemist and pharmacist Johann Christian Wiegleb. He determined that earth of alum could not be synthesized from silica and alkalis, contrary to contemporary belief.)  French chemist Jean Gello proved the earth in clay and the earth resulting from the reaction of an alkali on alum were identical in 1739. German chemist Johann Heinrich Pott showed the precipitate obtained from pouring an alkali into a solution of alum was different from lime and chalk in 1746.
+German chemist Andreas Sigismund Marggraf synthesized the earth of alum by boiling clay in sulfuric acid and adding potash in 1754. He realized that adding soda, potash, or an alkali to a solution of the new earth in sulfuric acid yielded alum. He described the earth as alkaline, as he had discovered it dissolved in acids when dried. Marggraf also described salts of this earth: chloride, nitrate and acetate. In 1758, French chemist Pierre Macquer wrote that alumina resembled a metallic earth. In 1760, French chemist Théodore Baron d'Hénouville expressed his confidence that alumina was a metallic earth.
+In 1767, Swedish chemist Torbern Bergman synthesized alum by boiling alunite in sulfuric acid and adding potash to the solution. He also synthesized alum as a reaction product between sulfates of potassium and earth of alum, demonstrating that alum was a double salt. Swedish German pharmaceutical chemist Carl Wilhelm Scheele demonstrated that both alum and silica originated from clay and alum did not contain silicon in 1776. Writing in 1782, French chemist Antoine Lavoisier  considered alumina an oxide of a metal with an affinity for oxygen so strong that no known reducing agents could overcome it.
+Swedish chemist Jöns Jacob Berzelius suggested the formula AlO3 for alumina in 1815. The correct formula, Al2O3, was established by German chemist Eilhard Mitscherlich in 1821; this helped Berzelius determine the correct atomic weight of the metal, 27.
+
+== Isolation of metal ==
+
+In 1760, Baron de Hénouville unsuccessfully attempted to reduce alumina to its metal. He claimed he had tried every method of reduction known at the time, though his methods were unpublished. It is probable he mixed alum with carbon or some organic substance, with salt or soda for flux, and heated it in a charcoal fire. Austrian chemists Anton Leopold Ruprecht and Matteo Tondi repeated Baron's experiments in 1790, significantly increasing the temperatures. They found small metallic particles they believed were the sought-after metal; but later experiments by other chemists showed these were iron phosphide from impurities in the charcoal and bone ash. German chemist Martin Heinrich Klaproth commented in an aftermath, "if there exists an earth which has been put in conditions where its metallic nature should be disclosed, if it had such, an earth exposed to experiments suitable for reducing it, tested in the hottest fires by all sorts of methods, on a large as well as on a small scale, that earth is certainly alumina, yet no one has yet perceived its metallization." Lavoisier in 1794 and French chemist Louis-Bernard Guyton de Morveau in 1795 melted alumina to a white enamel in a charcoal fire fed by pure oxygen but found no metal. American chemist Robert Hare melted alumina with an oxyhydrogen blowpipe in 1802, also obtaining the enamel, but still found no metal.
+In 1807, British chemist Humphry Davy successfully electrolyzed alumina with alkaline batteries, but the resulting alloy contained potassium and sodium, and Davy had no means to separate the desired metal from these. He then heated alumina with potassium, forming potassium oxide but was unable to produce the sought-after metal. In 1808, Davy set up a different experiment on electrolysis of alumina, establishing that alumina decomposed in the electric arc but formed metal alloyed with iron; he was unable to separate the two. Finally, he tried yet another electrolysis experiment, seeking to collect the metal on iron, but was again unable to separate the coveted metal from it. Davy suggested the metal be named alumium in 1808 and aluminum in 1812, thus producing the modern name. Other scientists used the spelling aluminium; the former spelling regained usage in the United States in the following decades.
+American chemist Benjamin Silliman repeated Hare's experiment in 1813 and obtained small granules of the sought-after metal, which almost immediately burned.

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+title: "History of aluminium"
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+
+In 1824, Danish physicist Hans Christian Ørsted attempted to produce the metal. He reacted anhydrous aluminium chloride with potassium amalgam, yielding a lump of metal that looked similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1826, he wrote, "aluminium has a metallic luster and somewhat grayish color and breaks down water very slowly"; this suggests he had obtained an aluminium–potassium alloy, rather than pure aluminium. Ørsted placed little importance on his discovery. He did not notify either Davy or Berzelius, both of whom he knew, and published his work in a Danish magazine unknown to the European public. As a result, he is often not credited as the discoverer of the element; some earlier sources claimed Ørsted had not isolated aluminium.
+Berzelius tried isolating the metal in 1825 by carefully washing the potassium analog of the base salt in cryolite in a crucible. Prior to the experiment, he had correctly identified the formula of this salt as K3AlF6. He found no metal, but his experiment came very close to succeeding and was successfully reproduced many times later. Berzelius's mistake was in using an excess of potassium, which made the solution too alkaline and dissolved all the newly formed aluminium.
+
+German chemist Friedrich Wöhler visited Ørsted in 1827 and received explicit permission to continue the aluminium research, which Ørsted "did not have time" for. Wöhler repeated Ørsted's experiments but did not identify any aluminium. (Wöhler later wrote to Berzelius, "what Oersted assumed to be a lump of aluminium was certainly nothing but aluminium-containing potassium".) He conducted a similar experiment, mixing anhydrous aluminium chloride with potassium (the Wöhler process), and produced a powder of aluminium. After hearing about this, Ørsted suggested that his own aluminium might have contained potassium. Wöhler continued his research and in 1845 was able to produce small pieces of the metal and described some of its physical properties. Wöhler's description of the properties indicates that he had obtained impure aluminium. Other scientists also failed to reproduce Ørsted's experiment, and Wöhler was credited as the discoverer for many years. While Ørsted was not concerned with the priority of the discovery,  some Danes tried to demonstrate he had obtained aluminium. In 1921, the reason for the inconsistency between Ørsted's and Wöhler's experiments was discovered by Danish chemist Johan Fogh, who demonstrated that Ørsted's experiment was successful thanks to use of a large amount of excess aluminium chloride and an amalgam with low potassium content. In 1936, scientists from American aluminium producing company Alcoa successfully recreated that experiment. However, many later sources still credit Wöhler with the discovery of aluminium, as well as its successful isolation in a relatively pure form.
+
+== Early industrial production ==
+My first thought was I had laid my hands on this intermediate metal which would find its place in man's uses and needs when we would find the way of taking it out of the chemists' laboratory and putting it in the industry. 
+Since Wöhler's method could not yield large amounts of aluminium, the metal remained uncommon; its cost had exceeded that of gold before a new method was devised. In 1852, aluminium was sold at US$34 per ounce. In comparison, the price of gold at the time was $19 per ounce.
+
+French chemist Henri Étienne Sainte-Claire Deville announced an industrial method of aluminium production in 1854 at the French Academy of Sciences in Paris. Aluminium chloride could be reduced by sodium, a metal more convenient and less expensive than potassium used by Wöhler. Deville was able to produce an ingot of the metal. Napoleon III of France promised Deville an unlimited subsidy for aluminium research; in total, Deville used 36,000 French francs—20 times the annual income of an ordinary family. Napoleon's interest in aluminium lay in its potential military use: he wished weapons, helmets, armor, and other equipment for the French army could be made of the new light, shiny metal. While the metal was still not displayed to the public, Napoleon is reputed to have held a banquet where the most honored guests were given aluminium utensils while others made do with gold.
+Twelve small ingots of aluminium were later exhibited for the first time to the public at the Exposition Universelle of 1855. The metal was presented as "the silver from clay" (aluminium is very similar to silver visually), and this name was soon widely used. It attracted widespread attention; it was suggested aluminium be used in arts, music, medicine, cooking, and tableware. The metal was noticed by the avant-garde writers of the time—Charles Dickens, Nikolay Chernyshevsky, and Jules Verne—who envisioned its use in the future. However, not all attention was favorable. Newspapers wrote, "The Parisian expo put an end to the fairy tale of the silver from clay", saying that much of what had been said about the metal was exaggerated if not untrue and that the amount of the presented metal—about a kilogram—contrasted with what had been expected and was "not a lot for a discovery that was said to turn the world upside down". Overall, the fair led to the eventual commercialization of the metal. That year, aluminium was put to the market at a price of 300 F per kilogram. At the next fair in Paris in 1867, visitors were presented with aluminium wire and foil as well a new alloy—aluminium bronze, notable for its low cost of production, high resistance to corrosion, and desirable mechanical properties.

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+
+Manufacturers did not wish to divert resources from producing well-known (and marketable) metals, such as iron and bronze, to experiment with a new one; moreover, produced aluminium was still not of great purity and differed in properties by sample. This led to an initial general reluctance to produce the new metal. Deville and partners established the world's first industrial production of aluminium at a smelter in Rouen in 1856. Deville's smelter moved that year to La Glacière and then Nanterre, and in 1857 to Salindres. For the factory in Nanterre, an output of 2 kilograms of aluminium per day was recorded, with a purity of 98%. Originally, production started with synthesis of pure alumina, which was obtained from calcination of ammonium alum. In 1858, Deville was introduced to bauxite and, in collaboration with Louis Le Châtelier, soon developed what became known as the Deville–Pechiney process, employing the mineral as a source for alumina production. In 1860, Deville sold his aluminium interests to Henri Merle, a founder of Compagnie d'Alais et de la Camargue; this company dominated the aluminium market in France decades later.
+
+Some chemists, including Deville, sought to use cryolite as the source ore, but with little success. British engineer William Gerhard set up a plant with cryolite as the primary raw material in Battersea, London, in 1856, but technical and financial difficulties forced the closure of the plant in three years. British ironmaster Isaac Lowthian Bell produced aluminium from 1860 to 1874. During the opening of his factory, he waved to the crowd with a unique and costly aluminium top hat. No statistics about this production can be recovered, but it "cannot be very high". Deville's output grew to 1 metric ton per year in 1860; 1.7 metric tons in 1867; and 1.8 metric tons in 1872. At the time, demand for aluminium was low: for example, sales of Deville's aluminium by his British agents equaled 15 kilograms in 1872. Aluminium at the time was often compared with silver; like silver, it was found to be suitable for making jewelry and objéts d'art. Price for aluminium steadily declined to 240 F in 1859; 200 F in 1862; 120 F in 1867.
+Other production sites began to appear in the 1880s. British engineer James Fern Webster launched the industrial production of aluminium by reduction with sodium in 1882; his aluminium was much purer than Deville's (it contained 0.8% impurities whereas Deville's typically contained 2%). World production of aluminium in 1884 equaled 3.6 metric tons. In 1884, American architect William Frishmuth combined production of sodium, alumina, and aluminium into a single technological process; this contrasted with the previous need to collect sodium, which combusts in water and sometimes air; his aluminium production cost was about $16 per pound (compare to silver's cost of $19 per pound, or the French price, an equivalent of $12 per pound). In 1885, Aluminium- und Magnesiumfabrik started production in Hemelingen. Its production figures strongly exceeded those of the factory in Salindres but the factory stopped production in 1888. In 1886, American engineer Hamilton Castner devised a method of cheaper production of sodium, which decreased the cost of aluminium production to $8 per pound, but he did not have enough capital to construct a large factory like Deville's. In 1887, he constructed a factory in Oldbury; Webster constructed a plant nearby and bought Castner's sodium to use it in his own production of aluminium. In 1889, German metallurgist Curt Netto launched a method of reduction of cryolite with sodium that produced aluminium containing 0.5–1.0% of impurities.
+
+== Electrolytic production and commercialization ==
+I'm going for that metal. 

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+
+Aluminium was first produced independently using electrolysis in 1854 by the German chemist Robert Bunsen and Deville. Their methods did not become the basis for industrial production of aluminium because electrical supplies were inefficient at the time. This changed only with Belgian engineer Zénobe Gramme's invention of the dynamo in 1870, which made creation of large amounts of electricity possible. The invention of the three-phase current by Russian engineer Mikhail Dolivo-Dobrovolsky in 1889 made transmission of this electricity over long distances achievable. Soon after his discovery, Bunsen moved on to other areas of interest while Deville's work was noticed by Napoleon III; this was the reason Deville's Napoleon-funded research on aluminium production had been started. Deville quickly realized electrolytic production was impractical at the time and moved on to chemical methods, presenting results later that year.
+Electrolytic mass production remained difficult because electrolytic baths could not withstand prolonged contact with molten salts, succumbing to corrosion. The first attempt to overcome this for aluminium production was made by American engineer Charles Bradley in 1883. Bradley heated aluminium salts internally: the highest temperature was inside the bath and the lowest was on its walls, where salts would solidify and protect the bath. Bradley then sold his patent claim to brothers Alfred and Eugene Cowles, who used it at a smelter in Lockport and later in Stoke-upon-Trent but the method was modified to yield alloys rather than pure aluminium. Bradley applied for a patent in 1883; due to his broad wordings, it was rejected as composed of prior art. After a necessary two-year break, he re-applied. This process lasted for six years, as the patent office questioned whether Bradley's ideas were original. When Bradley was granted a patent, electrolytic aluminium production had already been in place for several years.
+The first large-scale production method was independently developed by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886; it is now known as the Hall–Héroult process. Pure alumina's very high melting point made electrolysis impractical; both Héroult and Hall realized it could be greatly lowered by the presence of molten cryolite. Héroult was granted a patent in France in April and subsequently in several other European countries; he also applied for a U.S. patent in May. After securing a patent, Héroult could not find interest in his invention. When asking professionals for advice, he was told there was no demand for aluminium but some for aluminium bronze. The factory in Salindres did not wish to improve its process. In 1888, Héroult and his companions founded Aluminium Industrie Aktiengesellschaft and started industrial production of aluminium bronze in Neuhausen am Rheinfall. Then, Société électrométallurgique française was founded in Paris. They convinced Héroult to return to France, purchased his patents, and appointed him as the director of a smelter in Isère, which produced aluminium bronze on a large scale at first and pure aluminium in a few months.
+
+At the same time, Hall produced aluminium by the same process in his home at Oberlin. He applied for a patent in July, and the patent office notified Hall of an "interference" with Héroult's application. The Cowles brothers offered legal support. By then, Hall had failed to develop a commercial process for his first investors, and he turned to experimenting at Cowles' smelter in Lockport. He experimented for a year without much success but gained the attention of investors. Hall co-founded the Pittsburgh Reduction Company in 1888 and initiated production of aluminium.  Hall's patent was granted in 1889. In 1889, Hall's production began to use the principle of internal heating. By September 1889, Hall's production grew to 385 pounds (175 kilograms) at a cost of $0.65 per pound. By 1890, Hall's company still lacked capital and did not pay dividends; Hall had to sell some of his shares to attract investments. During that year, a new factory in Patricroft was constructed. The smelter in Lockport was unable to withstand the competition and shut down by 1892.
+The Hall–Héroult process converts alumina into the metal. Austrian chemist Carl Josef Bayer discovered a way of purifying bauxite to yield alumina in 1888 at a textile factory in Saint Petersburg and was issued a patent later that year; this is now known as the Bayer process. Bayer sintered bauxite with alkali and leached it with water; after stirring the solution and introducing a seeding agent to it, he found a precipitate of pure aluminium hydroxide, which decomposed to alumina on heating. In 1892, while working at a chemical plant in Yelabuga, he discovered the aluminium contents of bauxite dissolved in the alkaline leftover from isolation of alumina solids; this was crucial for the industrial employment of this method. He was issued a patent later that year.
+The total amount of unalloyed aluminium produced using Deville's chemical method from 1856 to 1889 equaled 200 metric tons. Production in 1890 alone was 175 metric tons. It grew to 715 metric tons in 1893 and to 4,034 metric tons in 1898. The price fell to $2 per pound in 1889 and to $0.5 per pound in 1894.
+
+By the end of 1889, a consistently high purity of aluminium produced via electrolysis had been achieved. In 1890, Webster's factory went obsolete after an electrolysis factory was opened in England. Netto's main advantage, the high purity of the resulting aluminium, was outmatched by electrolytic aluminium and his company closed the following year. Compagnie d'Alais et de la Camargue also decided to switch to electrolytic production, and their first plant using this method was opened in 1895.
+Modern production of the aluminium is based on the Bayer and Hall–Héroult processes. It was further improved in 1920 by a team led by Swedish chemist Carl Wilhelm Söderberg. Previously, anode electrodes had been made from pre-baked coal blocks, which quickly corrupted and required replacement; the team introduced continuous electrodes made from a coke and tar paste in a reduction chamber. This advance greatly increased the world output of aluminium.
+
+== Mass usage ==

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+Prices for aluminium declined, and by the early 1890s, the metal had become widely used in jewelry, eyeglass frames, optical instruments, and many everyday items. Aluminium cookware began to be produced in the late 19th century and gradually supplanted copper and cast iron cookware in the first decades of the 20th century. Aluminium foil was popularized at that time. Aluminium is soft and light, but it was soon discovered that alloying it with other metals could increase its hardness while preserving its low density. Aluminium alloys found many uses in the late 19th and early 20th centuries. For instance, aluminium bronze is applied to make flexible bands, sheets, and wire, and is widely employed in the shipbuilding and aviation industries. Aviation used a new aluminium alloy, duralumin, invented in 1903. Aluminium recycling began in the early 1900s and has been used extensively since as aluminium is not impaired by recycling and thus can be recycled repeatedly. At this point, only the metal that had not been used by end-consumers was recycled. During World War I, major governments demanded large shipments of aluminium for light strong airframes. They often subsidized factories and the necessary electrical supply systems. Overall production of aluminium peaked during the war: world production of aluminium in 1900 was 6,800 metric tons; in 1916, annual production exceeded 100,000 metric tons. The war created a greater demand for aluminium, which the growing primary production was unable to fully satisfy, and recycling grew intensely as well. The peak in production was followed by a decline, then a swift growth.
+
+During the first half of the 20th century, the real price for aluminium fell continuously from $14,000 per metric ton in 1900 to $2,340 in 1948 (in 1998 United States dollars). There were some exceptions such as the sharp price rise during World War I. Aluminium was plentiful, and in 1919 Germany began to replace its silver coins with aluminium ones; more and more denominations were switched to aluminium coins as hyperinflation progressed in the country. By the mid-20th century, aluminium had become a part of everyday lives, becoming an essential component of housewares. Aluminium freight cars first appeared in 1931. Their lower mass allowed them to carry more cargo. During the 1930s, aluminium emerged as a civil engineering material used in both basic construction and building interiors. Its use in military engineering for both airplanes and tank engines advanced.
+Aluminium obtained from recycling was considered inferior to primary aluminium because of poorer chemistry control as well as poor removal of dross and slags. Recycling grew overall but depended largely on the output of primary production: for instance, as electric energy prices declined in the United States in the late 1930s, more primary aluminium could be produced using the energy-expensive Hall–Héroult process. This rendered recycling less necessary, and thus aluminium recycling rates went down. By 1940, mass recycling of post-consumer aluminium had begun.
+
+During World War II, production peaked again, exceeding 1,000,000 metric tons for the first time in 1941. Aluminium was used heavily in aircraft production and was a strategic material of extreme importance; so much so that when Alcoa (successor of Hall's Pittsburgh Reduction Company and the aluminium production monopolist in the United States at the time) did not expand its production, the United States Secretary of the Interior proclaimed in 1941, "If America loses the war, it can thank the Aluminum Corporation of America". In 1939, Germany was the world's leading producer of aluminium; the Germans thus saw aluminium as their edge in the war. Aluminium coins continued to be used but while they symbolized a decline on their introduction, by 1939, they had come to represent power. (In 1941, they began to be withdrawn from circulation to save the metal for military needs.) After the United Kingdom was attacked in 1940, it started an ambitious program of aluminium recycling; the newly appointed Minister of Aircraft Production appealed to the public to donate any household aluminium for airplane building. The Soviet Union received 328,100 metric tons of aluminium from its co-combatants from 1941 to 1945; this aluminium was used in aircraft and tank engines. Without these shipments, the output of the Soviet aircraft industry would have fallen by over a half.
+After the wartime peak, world production fell for three late-war and post-war years but then regained its rapid growth. In 1954, the world output equaled 2,810,000 metric tons; this production surpassed that of copper, historically second in production only to iron, making it the most produced non-ferrous metal.
+
+== Aluminium Age ==
+
+Earth's first artificial satellite Sputnik 1, launched in 1957, consisted of two joined aluminium hemispheres. All subsequent spacecraft have used aluminium to some extent. The aluminium can was first manufactured in 1956 and employed as a container for drinks in 1958. In the 1960s, aluminium was employed for the production of wires and cables. Since the 1970s, high-speed trains have commonly used aluminium for its high strength-to-weight ratio. For the same reason, the aluminium content of cars is growing.
+Six major companies dominated the world market by 1955: Alcoa, Alcan (originated as a part of Alcoa), Reynolds, Kaiser, Pechiney (merger of Compagnie d'Alais et de la Camargue that bought Deville's smelter and Société électrométallurgique française that hired Héroult), and Alusuisse (successor of Héroult's Aluminium Industrie Aktien Gesellschaft); their combined share of the market equaled 86%. From 1945, aluminium consumption grew by almost 10% each year for nearly three decades, gaining ground in building applications, electric cables, basic foils and the aircraft industry. In the early 1970s, an additional boost came from the development of aluminium beverage cans. The real price declined until the early 1970s; in 1973, the real price equaled $2,130 per metric ton (in 1998 United States dollars). The main drivers of the drop in price was the decline of extraction and processing costs, technological progress, and the increase in aluminium production, which first exceeded 10,000,000 metric tons in 1971.

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+In the late 1960s, governments became aware of waste from the industrial production; they enforced a series of regulations favoring recycling and waste disposal. Söderberg anodes, which save capital and labor to bake the anodes but are more harmful to the environment (because of a greater difficulty in collecting and disposing of the baking fumes), fell into disfavor, and production began to shift back to the pre-baked anodes. The aluminium industry began promoting the recycling of aluminium cans in an attempt to avoid restrictions on them. This sparked recycling of aluminium previously used by end-consumers: for example, in the United States, levels of recycling of such aluminium increased 3.5 times from 1970 to 1980 and 7.5 times to 1990. Production costs for primary aluminium grew in the 1970s and 1980s, and this also contributed to the rise of aluminium recycling. Closer composition control and improved refining technology diminished the quality difference between primary and secondary aluminium.
+In the 1970s, the increased demand for aluminium made it an exchange commodity; it entered the London Metal Exchange, the world's oldest industrial metal exchange, in 1978. Since then, aluminium has been traded for United States dollars and its price fluctuated along with the currency's exchange rate. The need to exploit lower-grade poorer quality deposits and fast increasing input costs of energy, but also bauxite, as well as changes in exchange rates and greenhouse gas regulation, increased the net cost of aluminium; the real price grew in the 1970s.
+
+The increase of the real price, and changes of tariffs and taxes, began the redistribution of world producers' shares: the United States, the Soviet Union, and Japan accounted for nearly 60% of world's primary production in 1972 (and their combined share of consumption of primary aluminium was also close to 60%); but their combined share only slightly exceeded 10% in 2012. The production shift began in the 1970s with production moving from the United States, Japan, and Western Europe to Australia, Canada, the Middle East, Russia, and China, where it was cheaper due to lower electricity prices and favorable state regulation, such as low taxes or subsidies. Production costs in the 1980s and 1990s declined because of advances in technology, lower energy and alumina prices, and high exchange rates of the United States dollar.
+In the 2000s, the BRIC countries' (Brazil, Russia, India and China) combined share grew from 32.6% to 56.5% in primary production and 21.4% to 47.8% in primary consumption. China has accumulated an especially large share of world production, thanks to an abundance of resources, cheap energy, and governmental stimuli; it also increased its share of consumption from 2% in 1972 to 40% in 2010. The only other country with a two-digit percentage was the United States with 11%; no other country exceeded 5%. In the United States, Western Europe and Japan, most aluminium was consumed in transportation, engineering, construction, and packaging.
+
+In the mid-2000s, increasing energy, alumina and carbon (used in anodes) prices caused an increase in production costs. This was amplified by a shift in currency exchange rates: not only a weakening of the United States dollar, but also a strengthening of the Chinese yuan. The latter became important as most Chinese aluminium was relatively cheap.
+World output continued growing: in 2018, it was a record 63,600,000 metric tons before falling slightly in 2019. Aluminium is produced in greater quantities than all other non-ferrous metals combined. Its real price (in 1998 United States dollars) in 2019 was $1,400 per metric ton ($2,190 per ton in contemporary dollars).
+
+== See also ==
+
+List of countries by aluminium production
+
+== Notes ==
+
+== References ==
+
+== Bibliography ==
+Drozdov, Andrey (2007). Aluminium: The Thirteenth Element (PDF). RUSAL Library. ISBN 978-5-91523-002-5. Archived from the original (PDF) on 2016-04-16. Retrieved 2019-06-09.
+McNeil, Ian (2002). An Encyclopedia of the History of Technology. Routledge. ISBN 978-1-134-98165-6.
+Nappi, Carmine (2013). The global aluminium industry 40 years from 1972 (PDF) (Report). International Aluminium Institute.
+Richards, Joseph William (1896). Aluminium: Its history, occurrence, properties, metallurgy and applications, including its alloys (3 ed.). Henry Carey Baird & Co.
+Skrabec, Quentin R. (2017). Aluminum in America: A History. McFarland. ISBN 978-1-4766-2564-5.

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+title: "History of cosmetics"
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+
+The history of cosmetics spans at least 7,000 years and is present in almost every society on earth. Cosmetic body art is argued to have been the earliest form of a ritual in human culture. The evidence for this comes in the form of utilised red mineral pigments (red ochre) including crayons associated with the emergence of Homo sapiens in Africa. Cosmetics are mentioned in the Old Testament—2 Kings 9:30 where Jezebel painted her eyelids—approximately 840 BC—and the book of Esther describes various beauty treatments as well.
+Cosmetics were also used in ancient Rome, although much of Roman literature suggests that it was frowned upon. It is known that some women in ancient Rome invented make up including lead-based formulas, to whiten the skin, and kohl to line the eyes.
+
+== Africa ==
+
+=== Egypt ===
+
+One of the earliest cultures to use cosmetics was ancient Egypt, where both Egyptian men and women used makeup to enhance their appearance. The first cosmetics appeared 5,000 years ago in Egypt. To achieve a pleasant smell and softness of the skin, incense oils were used, and women applied white to protect their faces from the sun. The Egyptians were also the first to use black antimony-based paint as eyeliner. And to create a natural blush, they would crush flowers.
+The use of cosmetics in Ancient Egypt is well documented. Kohl has its roots in north Africa. The use of black kohl eyeliner and eyeshadows in dark colours such as blue, red, and black was common, and was commonly recorded and represented in Egyptian art, as well as being seen in Egyptian hieroglyphs. Ancient Egyptians utilized stone pallets to combine the material used to create cosmetic products. Cosmetic pallets were shaped into hieroglyphs, the most frequent being fish. Ancient Egyptians also extracted cosmetic face paint from fucus-algin, 0.01% iodine, and bromine mannite, however the bromine-based makeup was severely toxic. Lipsticks with shimmering effects were initially made using a pearlescent substance found in fish scales, which are still used extensively today. Despite the hazardous nature of some Egyptian cosmetics, ancient Egyptian makeup was also thought to have antibacterial properties that helped prevent infections. Remedies to treat wrinkles contained ingredients such as gum of frankincense and fresh moringa. For scars and burns, a special ointment was made of red ochre, kohl, and sycamore juice. An alternative treatment was a poultice of carob grounds and honey, or an ointment made of knotgrass and powdered root of wormwood. To improve breath the ancient Egyptians chewed herbs or frankincense which is still in use today. Jars of what could be compared with setting lotion have been found to contain a mixture of beeswax and resin. These doubled as remedies for problems such as baldness and greying hair. They also used these products on their mummies, because they believed that it would make them irresistible in the after life.
+
+=== Madagascar ===
+Women of the Sakalava and Vezo peoples in Madagascar began wearing masonjoany, a decorative paste made from ground wood, in the 9th century C.E. It is worn on the face as sunscreen and insect repellent, as well as decoration, with women painting flowers, leaves and stars in white and yellow pastes. The practice is derived from cultural exchange between Malagasy people and Arab merchants in the Northwest coastal region of the island.
+
+== Middle East ==
+Cosmetics are mentioned in the Old Testament, such as in 2 Kings 9:30, where the biblical figure Jezebel painted her eyelids (approximately 840 BC). Cosmetics are also mentioned in the book of Esther, where beauty treatments are described.
+Both sexes used cosmetics throughout the pre-Islamic Near East, going back to the civilizations of ancient Mesopotamia, Ancient Egypt, and Iran. Eye makeup in the form of kohl, were used in Persia and what today is Iran from ancient periods. Kohl is a black powder that was used widely across the Persian Empire. It was used as a powder or smeared to darken the edges of the eyelids similar to eyeliner. Cosmetics, especially kohl, played a significant role in the Middle East, highlighting not only its eye-protective aspects but also its cultural significance. The process of making kohl involved burning a substance to maintain a flame, a group of surfaces, and incorporating galena, a lead compound. Three items—jewelry, pottery, and seashells containing kohl—were buried with an ancient Emirati woman. Natural benefits of kohl also reduced eye swelling.
+The Middle East's adherence to Islamic rules shapes various aspects of daily life, including cosmetics and was also used throughout the Middle East and Near East after the advent of Islam. A specific type of kohl known as Ithmid kohl has been used for over 15 centuries in the region. In comparison to other types, Ithmid kohl not only has cosmetic benefits but also promotes health without harmful substances. Women used cosmetics widely in the private sphere, while only female slaves and singers tended to use them in public. Ointments, powders, and pastes were used as skin-lightening agents to comply with the era's beauty standards. Perfumed creams were also used on the face, as were sandalwood-based pastes to protect the skin from sunlight. Decorative henna was used during wedding celebrations to beautify the bride. Men and children used kohl on their eyes and henna as a natural dye for their hair, but rarely used other cosmetic items.

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+
+=== Henna ===
+Henna has a particular significance in Middle Eastern cosmetic techniques. It is used for both practical and ornamental purposes, especially at weddings, Eid, and Ramadan. The application method is combining dried henna powder with water, lemon juice, strong tea, and additional substances to make a paste. After that, the paste is applied to the skin in intricate patterns, frequently with the use of a brush or cone. A reddish-brown stain that might remain for several weeks is left behind when the dried paste peels off after a few hours. In Middle Eastern societies, this art form has been passed down through the years and is seen as a means of celebration and self-expression.
+In addition to its ceremonial use, henna can be used as an alternative for hair and nail polish, particularly on special occasions. Beyond its artistic designs, henna is used in Muslim marriage rituals to paint certain patterns on the skin that are said to bring blessings, or barakah. Henna was also a helpful way to stay cool during the summer. The cultural and symbolic value of henna in the Middle East is enhanced by these designs. In the Middle East, older women typically apply henna as a cosmetic procedure to symbolize tradition, experience, and wisdom. By connecting generations, this tradition not only preserves cultural identity but also promotes intercultural understanding.
+
+== Asia ==
+In the Indus Valley Civilization (c. 2500 BCE), archaeological excavations at Mohenjo-daro and Harappa have revealed small cosmetic containers, applicators, and evidence of pigments used for personal adornment.
+Traditional Indian practices included the use of kajal (kohl) to darken the eyes, believed to be both aesthetic and protective against glare and the evil eye.
+The application of sindoor (vermillion) in the hair parting by married women, and the use of mehndi (henna) for body decoration, also trace back to ancient Indian customs and remain culturally significant today.
+
+=== China ===
+
+ 
+Flowers play an important decorative role in China. Legend has it that once on the 7th day of the 1st lunar month, while Princess Shouyang, daughter of Emperor Wu of Liu Song, was resting under the eaves of Hanzhang Palace near the plum trees after wandering in the gardens, a plum blossom drifted down onto her fair face, leaving a floral imprint on her forehead that enhanced her beauty further. The court ladies were said to be so impressed, that they started decorating their own foreheads with a small delicate plum blossom design. This is also the mythical origin of the floral fashion, meihua zhuang (梅花妝, 'plum blossom makeup'), that originated in the Southern dynasties (420–589) and became popular amongst ladies in the Tang (618–907) and Song (960–1279) dynasties. The use of nail polish originated around 3000 BC in China, when the staining of nails was utilized by members of the upper class. Nail stains were produced from ingredients such as egg whites, beeswax, roses, and arabic gum. The colors used to stain nails became symbols of social class, as only the powerful could have red, gold, or silver stained nails. Nail cosmetics were reserved for the elite, and its use would be considered criminal for members of the lower class.
+
+=== Mongolia ===
+Women of royal families painted red spots on the center of their cheeks, right under their eyes. However, it is a mystery why. They said that red cheeks (face blush) are a sign of a happy queen. Blush helps to enhance the face shape to bring out the cheek bones.
+
+=== Japan ===
+
+In Japan, geisha wore lipstick made of crushed safflower petals to paint the eyebrows and edges of the eyes as well as the lips, and sticks of bintsuke wax, a softer version of the sumo wrestlers' hair wax, were used by geisha as a makeup base. Rice powder colors the face and back; rouge contours the eye socket and defines the nose.[unreliable source?] Ohaguro (black paint) colours the teeth for the ceremony, called Erikae, when maiko (apprentice geisha) graduate and become independent. The geisha would also sometimes use bird droppings to compile a lighter color. The beginning of the modern Japanese cosmetic industry began after the Meiji Restoration in 1868. New products began appearing in the markets for skin care and dermatology due to new ingredients and technologies.
+
+== Europe ==
+
+=== Antiquity ===
+Cosmetics were used by ancient Greeks and the Romans. During the Roman Empire, the use of cosmetics was common amongst prostitutes and rich women. Such adornment was sometimes lamented by certain Roman writers, who thought it to be against the castitas required of women by what they considered traditional Roman values. Pliny the Elder mentioned cosmetics in his Naturalis Historia, and Ovid wrote a book on the topic. Later Christian writers expressed similar sentiments.

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+
+=== Medieval Europe ===
+The Galenic model of health equates good skin to good health. Bad skin indicated humoral imbalance and was associated with lower socioeconomic status. That being said, smooth, soft, even, pale complexions were the beauty standard during the European Middle Ages Beauty was equated with moral goodness and harmony with the universe. While skincare was seen as a practice to take care of one’s health, paint or makeup was seen as deceitful because it covered rather than enhanced the natural complexion. Skin tone was affected by changes in climate, health, emotion, or diet. Therefore, by using make-up, women could stabilize their complexions. For instance, cosmetics were used to hide anything that seemed undesirable or a marker of bad health by removing puffiness from the face and eyes, lightening the skin, covering blemishes, and removing unwanted hair. The use of cosmetics continued in Middle Ages, where the face was whitened and the cheeks rouged. Thirteenth century Italian women wore red lipstick to show that they were of high social standing.
+Skincare was seen as medicinal, and involved language such as “heal” and “cure” when the products were marketed to both men and women. Recipes for skincare products were often seen in books with medicinal recipes. Many recipes were recorded for curing various skin issues like acne, redness, and dryness with face washes and ointments. Despite medicine being a male dominated space, skincare allowed women to show some expertise in science and medicine. Anna Hebrea of Rome (fl. 1508), cosmetologist of the Countess of Fiorlì Caterina Sforza (1463-1509), were some of the early modern women who experimented with the production of makeups in Europe.
+Another prevalent beauty standard was healthy hair; many cosmetic treatments were concocted to address balding by stimulating hair growth. Different regions dictated which hair color was the most desirable. For example, women would dye their hair blond in regions of Italy, England, France, Castile, and Aragon.
+While beauty was a sign of health and goodness, methods to achieve beauty could be harmful. Some cosmetics ingredients were detrimental to human health, such as white lead, mercury, agaric, and blackenbane. White lead was commonly used in facial creams and hair dyes, agaric was used as a lip ointment, and blackenbane was used to dye hair black. Mercury was used on severe facial scabies, to whiten the skin, and a multitude of other ailments.
+The Renaissance theater frequently referenced and utilized cosmetics. For instance, recipes for creams, face-whiteners, and rouges were described in many early modern play texts. This medium allowed beauty techniques available to illiterate women and to those who did not have access to recipe books. Makeup also played a crucial role in representing both race and gender. Blackface was used to emphasize whiteness by contrast, reinforcing the idea of being white as "normal." This went beyond mere entertainment as it represented racial stereotypes and the notion of Blackness as inferior. Whereas, whiteface on young male actors helped convey femininity. The theater showed how race could be removed or “applied” through cosmetics.
+
+=== 19th century onwards ===
+Cosmetics continued to be used in the following centuries, though attitudes towards cosmetics varied throughout time, with the use of cosmetics being openly frowned upon at many points in Western history. In the 19th century, Queen Victoria publicly declared makeup improper, vulgar, and acceptable only for use by actors,  with many famous actresses of the time, such as Sarah Bernhardt and Lillie Langtry using makeup.
+19th-century fashion ideals of women appearing delicate, feminine and pale were achieved by some through the use of makeup, with some women discreetly using rouge on their cheeks and drops of belladonna to dilate their eyes to appear larger. Though cosmetics were used discreetly by many women, makeup in Western cultures during this time was generally frowned upon, particularly during the 1870s, when Western social etiquette increased in rigidity. Teachers and clergy were specifically forbidden from the use of cosmetic products.
+
+== Latin America ==
+Beauty standards varied by tribes. Cosmetics was typically describing an individual's social class. These tribes tend to have the product on their bodies in addition to their face. In Colombia, cosmetic products used oil or petroleum with various colors for the face and vermillion for the body. More color indicates the woman of higher class. For Nicaragua, the arms were painted with a mixture consisting of wool and the individual's blood. Like the Colombian women, the petroleum is used with the exception of the breasts to prevent interference with child development.
+The Maya utilized the color red to represent social class and also used the color in funeral processes. The pigment was produced with mercury, lead, and arsenic. Other products to make the red color includes animals and plants. These items helped create more variety of reds with various tones, intensity, and sheen. Different shades of red determine a person's social status as red was represented luxury. Other colors in Maya society were blue and green made with Indigofera, malachite, azurite, veszelyite, and copper-containing minerals. Similar to red, the colors were also used in funerals and used to represent royalty. Orange and yellow were used with the same purpose of prestige being produced with hematite, goethite, and limonite.
+The body was considered as their portrait to the Maya with various images of plants, animals, and humans being common images. Other designs include personal designs using geometry.
+The Chinchorro culture in northern Chile followed the same principle as the Mayans regarding the significance of the color red with it being found in mummies.
+
+== Modern ==
+
+=== 19th century ===

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+
+During the late 1800s, the Western cosmetics industry began to grow due to a rise in "visual self-awareness", a shift in the perception of color cosmetics, and improvements in the safety of products. Prior to the 19th century, limitations in lighting technology and access to reflective devices stifled people's ability to regularly perceive their appearance. This, in turn, limited the need for a cosmetic market and resulted in individuals creating and applying their own products at home. Several technological advancements in the latter half of the century, including the innovation of mirrors, commercial photography, marketing and electricity in the home and in public, increased consciousness of one's appearance and created a demand for cosmetic products that improved one's image.
+Face powders, rouges, lipstick and similar products made from home were found to have toxic ingredients, which deterred customers from their use. Discoveries of non-toxic cosmetic ingredients, such as Henry Tetlow's 1866 use of zinc oxide as a face powder, and the distribution of cosmetic products by established companies such as Rimmel, Guerlain, and Hudnut helped popularize cosmetics to the broader public. Skincare, along with "face painting" products like powders, also became in-demand products of the cosmetics industry. The mass advertisements of cold cream brands such as Pond's through billboards, magazines, and newspapers created a high demand for the product. These advertisement and cosmetic marketing styles were soon replicated in European countries, which further increased the popularity of the advertised products in Europe.
+
+=== 20th century ===

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+
+In the 1970s, at least five companies started producing make-up for African American women. Before the 1970s, makeup shades for Black women were limited. Face makeup and lipstick did not work for dark skin types because they were created for pale skin tones. These cosmetics that were created for pale skin tones only made dark skin appear grey. Makeup artists, such as Reggie Wells, who specialized in black women celebrities, such as Oprah Winfrey developed their own shades. Eventually, makeup companies created makeup that worked for richer skin tones, such as foundations and powders that provided a natural match. Popular companies like Astarté, Afram, Libra, Flori Roberts and Fashion Fair priced the cosmetics reasonably due to the fact that they wanted to reach out to the masses. In addition, Black women joined the consumer market in America for hair care. Due to innovations in technology in the 1940s and 1950s, Black women were given more options in hair straightening techniques. In 1954, George E. Johnson started the Johnson Product Company and introduced a safe straightening hair care system that could be purchased in stores and done at home. As America shifted into the 1960s and 1970s, the afro became a popular hairstyle and required a new set of beauty demands. The afro became a symbol of naturalness, and rose with the "Black is Beautiful Movement," as well as Black nationalism. Johnson Product Company created various hair care products to upkeep the Afro look. Products like Afro Sheen and Ultra Sheen became popular amongst Black consumers. As Black consumerism grew, White owned companies tried to make their way into the Black hair care industry. Clairol created products and advertisements that were aimed to support Black hair. From 1939 to 1945, during the Second World War, cosmetics were in short supply. Petroleum and alcohol, basic ingredients of many cosmetics, were diverted into war supply. Ironically, at this time when they were restricted, lipstick, powder, and face cream were most desirable and most experimentation was carried out for the post war period. Cosmetic developers realized that the war would result in a phenomenal boom afterwards, so they began preparing. Yardley, Elizabeth Arden, Helena Rubinstein, and the French manufacturing company became associated with "quality" after the war because they were the oldest established. Pond's had this same appeal in the lower price range. Gala cosmetics were one of the first to give its products fantasy names, such as the lipsticks in "lantern red" and "sea coral."
+During the 1960s and 1970s, many women in the western world influenced by feminism decided to go without any cosmetics. In 1968 at the feminist Miss America protest, protestors symbolically threw a number of feminine products into a "Freedom Trash Can." This included cosmetics, which were among items the protestors called "instruments of female torture" and accouterments of what they perceived to be enforced femininity. Cosmetics in the 1970s were divided into a "natural look" for day and a more sexualized image for evening. Non-allergic makeup appeared when the bare face was in fashion as women became more interested in the chemical value of their makeup. Modern developments in technology, such as the High-shear mixer facilitated the production of cosmetics which were more natural looking and had greater staying power in wear than their predecessors. The prime cosmetic of the time was eye shadow, though; women also were interested in new lipstick colors such as lilac, green, and silver. These lipsticks were often mixed with pale pinks and whites, so women could create their own individual shades. "Blush-ons" came into the market in this decade, with Revlon giving them wide publicity. This product was applied to the forehead, lower cheeks, and chin. Contouring and highlighting the face with white eye shadow cream also became popular. Avon introduced the lady saleswoman. In fact, the whole cosmetic industry in general opened opportunities for women in business as entrepreneurs, inventors, manufacturers, distributors, and promoters.

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+
+=== 21st century ===
+Beauty products are now widely available from dedicated internet-only retailers, who have more recently been joined online by established outlets, including major department stores and traditional brick-and-mortar beauty retailers.
+Like most industries, cosmetic companies resist regulation by government agencies. In the U.S., the Food and Drug Administration (FDA) does not approve or review cosmetics, although it does regulate the colors that can be used in hair dyes. Cosmetic companies are not required to report injuries resulting from use of their products.
+Although modern makeup has been used mainly by women traditionally, gradually an increasing number of males are using cosmetics usually associated to women to enhance their own facial features. Concealer is commonly used by cosmetic-conscious men. Cosmetics brands are releasing cosmetic products especially tailored for men, and men are using such products more commonly. There is some controversy over this, however, as many feel that men who wear makeup are neglecting traditional gender roles, and do not view men wearing cosmetics in a positive light. Others, however, view this as a sign of increasing gender equality and feel that men also have the right to enhance their facial features with cosmetics if women do.
+Today the market of cosmetics has a different dynamic compared to the 20th century. Some countries are driving this economy:
+
+Japan: Japan is the second largest market in the world. Regarding the growth of this market, cosmetics in Japan have entered a period of stability. However, the market situation is quickly changing. Now consumers can access a lot of information on the Internet and choose many alternatives, opening up many opportunities for newcomers entering the market, looking for chances to meet the diverse needs of consumers. The size of the cosmetics market for 2010 was 2286 billion yen on the basis of the value of shipments by brand manufacturer. With a growth rate of 0.1%, the market was almost unchanged from the previous year.
+Russia: One of the most interesting emerging markets, the 5th largest in the world in 2012, the Russian perfumery and cosmetics market has shown the highest growth of 21% since 2004, reaching US$13.5 billion.
+South Korea: South Korea's cosmetic industry is on the rise with its creations, light ingredients, and aesthetic packages. In 2020, the market amassed $6.8 billion with a $2.6 billion loss due to COVID-19. The total export of products and trade increased by 16 percent with France being the largest exporter followed by the United States and Japan. Skincare products remain to be the largest imported items at 34.17 percent along with perfumes and haircare products being other large, imported goods in 2021.
+With the imposition of lockdowns due to the COVID-19 pandemic and the consequent wariness to return to salons, trends that imitate salon procedures started to emerge, such as more complicated home skin-care regimens, hair color preserving products, and beauty tools. Early in the pandemic, sales on makeup essentials, like foundation and lipstick, decreased by up to 70% because of quarantining and face-covering mandates.
+In Latin America's cosmetic and personal-care industry, it has been increasing significantly and become much more diverse. Within the industry, the thought of sustainability in products are considered to find alternatives to silicone and palm sourced additives. Clariant being one of the companies producing such products. One item used in products is epseama derived from seaweed. The ingredient serves as an anti-aging agent in skin products.
+
+==== Men and makeup ====
+In the 1970s, male musicians began to use makeup onstage. This included famous rock stars such as David Bowie, Alice Cooper, and the band Kiss. The use of cosmetics allowed them to create an alter ego, and were part of the visual entertainment of their shows. Currently, the popularity of TikTok has created a rise in men's cosmetics. Some men have chosen to wear nail polish, makeup, and other cosmetics to express their identity online.
+
+== See also ==
+
+== References ==
+
+=== Sources ===
+Angeloglou, Maggie (1970). The History of Make-up. London, UK: Macmillan. OCLC 615683528.
+Peiss, Kathy Lee (1998). Hope in a Jar: The Making of America's Beauty Culture. Metropolitan Books. ISBN 978-0-8050-5550-4.
+Riordan, Teresa (2004). Inventing Beauty. New York City: Broadway Books. ISBN 0-7679-1451-1.
+
+== External links ==
+Forsling, Yvonne. "Regency Cosmetics and Make-Up: Looking Your Best in 1811". Regency England 1790-1830.
+"Naked face project: Women try no-makeup experiment". USA Today. 28 March 2012. Archived from the original on 30 March 2012. Retrieved 7 April 2012.
+Forsling, Yvonne. "Regency Cosmetics and Make-Up: Looking Your Best in 1811". Regency England 1790-1830.

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+title: "History of fluorine"
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+
+Fluorine is a relatively new element in human applications. In ancient times, only minor uses of fluorine-containing minerals existed. The industrial use of fluorite, fluorine's source mineral, was first described by early scientist Georgius Agricola in the 16th century, in the context of smelting. The name "fluorite" (and later "fluorine") derives from Agricola's invented Latin terminology. In the late 18th century, hydrofluoric acid was discovered. By the early 19th century, it was recognized that fluorine was a bound element within compounds, similar to chlorine. Fluorite was determined to be calcium fluoride.
+Because of fluorine's tight bonding as well as the toxicity of hydrogen fluoride, the element resisted many attempts to isolate it. In 1886, French chemist Henri Moissan, later a Nobel Prize winner, succeeded in making elemental fluorine by electrolyzing a mixture of potassium fluoride and hydrogen fluoride. Large-scale production and use of fluorine began during World War 2 as part of the Manhattan Project. Earlier in the century, the main fluorochemicals were commercialized by the DuPont company:  refrigerant gases (Freon) and polytetrafluoroethylene plastic (Teflon).
+
+== Ancient use ==
+
+Some instances of ancient use of fluorite, main source mineral of fluorine, for ornamental use carvings exist. However, archeological finds are rare, perhaps in part because of the stone's softness. Two Roman cups made of Persian fluorite have been discovered and are currently exhibited at the British museum. Pliny the Elder described a soft stone from Persia used in cups that may have been fluorite. Fluorite carvings from about 1000 AD have been discovered in the Americas in Indian burial grounds.
+
+== Early metallurgy ==
+
+The word "fluorine" derives from the Latin stem of the main source mineral, fluorite, which was first mentioned in 1529 by Georgius Agricola, the "father of mineralogy". He described fluorite as a flux—an additive that helps melt ores and slags during smelting. Fluorite stones were called schone flusse in the German of the time. Agricola, writing in Latin but describing 16th century industry, invented several hundred new Latin terms. For the schone flusse stones, he used the Latin noun fluores, "fluxes", because they made metal ores flow when in a fire. After Agricola, the name for the mineral evolved to fluorspar (still commonly used) and then to fluorite.
+Fluorite mineral was also described in the writings of alchemist Basilius Valentinus, supposedly in the late 15th century.  However, it is alleged that "Valentinus" was a hoax as his writings were not known until about 1600.
+
+== Hydrofluoric acid ==
+
+Some sources claim that the first production of hydrofluoric acid was by Heinrich Schwanhard, a German glass cutter, in 1670. A peer-reviewed study of Schwanhard's writings, though, showed no specific mention of fluorite and only discussion of an extremely strong acid. It was hypothesized that this was probably nitric acid or aqua regia, both capable of etching soft glass.
+Andreas Sigismund Marggraf made the first definite preparation of hydrofluoric acid in 1764 when he heated fluorite with sulfuric acid in glass, which was greatly corroded by the product.   In 1771, Swedish chemist Carl Wilhelm Scheele repeated this reaction. Scheele recognized the product of the reaction as an acid, which he called "fluss-spats-syran" (fluor-spar-acid); in English, it was known as "fluoric acid".
+
+== Recognition of the element ==
+
+In 1810, French physicist André-Marie Ampère suggested that hydrofluoric acid was a compound of hydrogen with an unknown element, analogous to chlorine. Fluorite was then shown to be mostly composed of calcium fluoride.
+Sir Humphry Davy originally suggested the name fluorine, taking the root from the name of "fluoric acid" and the -ine suffix, similarly to other halogens. This name, with modifications, came to most European languages. (Greek, Russian, and several other languages use the name ftor or derivatives, which was suggested by Ampère and comes from the Greek φθόριος (phthorios), meaning "destructive".) The New Latin name (fluorum) gave the element its current symbol, F, although the symbol Fl has been used in early papers.  The symbol Fl is now used for the super-heavy element flerovium.
+
+== Early isolation attempts ==
+
+Progress in isolating the element was slowed by the exceptional dangers of generating fluorine:  several 19th century experimenters, the "fluorine martyrs", were killed or blinded. Humphry Davy, as well as the notable French chemists Joseph Louis Gay-Lussac and Louis Jacques Thénard, experienced severe pains from inhaling hydrogen fluoride gas; Davy's eyes were damaged. Irish chemists Thomas and George Knox developed fluorite apparatus for working with hydrogen fluoride, but nonetheless were severely poisoned. Thomas nearly died and George was disabled for three years. French chemist Henri Moissan was poisoned several times, which shortened his life. Belgian chemist Paulin Louyet and French chemist Jérôme Nicklès tried to follow the Knox work, but they died from HF poisoning even though they were aware of the dangers.
+Initial attempts to isolate the element were also hindered by material difficulties:  the extreme corrosiveness and reactivity of hydrogen fluoride (and of fluorine gas) as well as problems getting a suitable conducting liquid for electrolysis. Davy tried to electrolyze HF but had to stop because the electrodes were damaged. He then shifted to (unsuccessful) chemical reactions.
+Edmond Frémy thought that passing electric current through pure hydrofluoric acid (dry HF) might work. Previously, hydrogen fluoride was only available in a water solution. Frémy therefore devised a method for producing dry hydrogen fluoride by acidifying potassium bifluoride (KHF2). Unfortunately, pure hydrogen fluoride did not pass an electric current. Frémy also tried electrolyzing molten calcium fluoride and probably produced some fluorine (since he made calcium metal at the other electrode), but he was unable to collect the gas.
+English chemist George Gore also tried electrolyzing dry HF and may have made small quantities of fluorine gas in 1860. He reported an explosion after running his cell (hydrogen and fluorine recombine dramatically), but he recognized that an oxygen leak could have also caused the reaction.
+
+== Moissan ==

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+---
+title: "History of fluorine"
+chunk: 2/2
+source: "https://en.wikipedia.org/wiki/History_of_fluorine"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:16.902729+00:00"
+instance: "kb-cron"
+---
+
+French chemist Henri Moissan, formerly one of Frémy's students, continued the search. After trying many different approaches, he built on Frémy and Gore's earlier attempts by combining potassium bifluoride and hydrogen fluoride. The resultant solution conducted electricity. Moissan also constructed especially corrosion-resistant equipment: containers crafted from a mixture of platinum and iridium (more chemically resistant than pure platinum) with fluorite stoppers.
+After 74 years of effort by many chemists, on 26 June 1886, Moissan isolated elemental fluorine.  Moissan's report to the French Academy of making fluorine showed appreciation for the feat:  "One can indeed make various hypotheses on the nature of the liberated gas; the simplest would be that we are in the presence of fluorine."
+Moissan's 1887 publication documents reaction attempts of fluorine gas with several substances: sulfur (flames), hydrogen (explosion), carbon (no reaction), etc. Later, Moissan devised a less expensive apparatus for making fluorine: copper equipment coated with copper fluoride.
+Moissan also constructed special apparatus—5m long platinum tubes with fluorite windows—to determine the slight yellow color of fluorine gas. (The gas appears transparent in small tubes or when allowed to escape. The color observation was not repeated until the 1980s, when his result was confirmed.)
+
+In 1906, two months before his death, Moissan received the Nobel Prize in chemistry.  The citation:
+
+...in recognition of the great services rendered by him in his investigation and isolation of the element fluorine...The whole world has admired the great experimental skill with which you have studied that savage beast among the elements.
+
+== Development ==
+
+During the 1930s and 1940s, the DuPont company commercialized organofluorine compounds at large scales. Following trials of chlorofluorocarbons as refrigerants by researchers at General Motors, DuPont developed large-scale production of Freon-12. The work was carried out by DuPont scientist Dr. Thomas Midgley Jr. DuPont and GM formed a joint venture in 1930 to market the new product; in 1949 DuPont took over the business. Freon proved to be a marketplace hit, rapidly replacing earlier, more toxic, refrigerants and growing the overall market for kitchen refrigerators.
+In 1938, polytetrafluoroethylene (Teflon) was discovered by accident by a recently hired DuPont PhD, Roy J. Plunkett. While working with a cylinder of tetrafluoroethylene, he was unable to release the gas, although the weight had not changed. Scraping down the container, he found white flakes of a polymer new to the world. Tests showed the substance was resistant to corrosion from most substances and had better high temperature stability than any other plastic. By early 1941, a crash program was making commercial quantities.
+Large-scale productions of elemental fluorine began during World War II. Germany used high-temperature electrolysis to produce tons of chlorine trifluoride, a compound planned to be used as an incendiary. The Manhattan Project in the United States produced even more fluorine for use in uranium separation. Gaseous uranium hexafluoride was used to separate uranium-235, an important nuclear explosive, from the heavier uranium-238 in diffusion plants. Because uranium hexafluoride releases small quantities of corrosive fluorine, the separation plants were built with special materials. All pipes were coated with nickel; joints and flexible parts were fabricated from Teflon.
+In 1958, a DuPont research manager in the Teflon business, Bill Gore, left the company because of its unwillingness to develop Teflon as wire-coating insulation. Gore's son Robert found a method for solving the wire-coating problem and the company W. L. Gore and Associates was born. In 1969, Robert Gore developed an expanded polytetrafluoroethylene (ePTFE) membrane which led to the large Gore-Tex business in breathable rainwear. The company developed many other uses of PTFE.
+In the 1970s and 1980s, concerns developed over the role chlorofluorocarbons play in damaging the ozone layer. By 1996, almost all nations had banned chlorofluorocarbon refrigerants and commercial production ceased. Fluorine continued to play a role in refrigeration though: hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) were developed as replacement refrigerants.
+
+== See also ==
+History of aluminium
+
+== Notes ==
+
+== Citations ==
+
+== Indexed references ==
+
+== External links ==
+(in French) Research in the isolation of Fluorine, 1887 report by Moissan with drawings, on the French Wikisource.

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+title: "History of gold"
+chunk: 1/3
+source: "https://en.wikipedia.org/wiki/History_of_gold"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:18.181634+00:00"
+instance: "kb-cron"
+---
+
+Gold is a chemical element; its chemical symbol is 'Au' (from Latin aurum) and atomic number 79. In its pure form, it is a bright-metallic-yellow, dense, soft, malleable, and ductile metal.
+75% of the presently accounted for gold has been extracted since 1910, two-thirds since 1950.
+
+== Overview ==
+
+=== Earliest recordings ===
+
+The earliest recorded metal employed by humans appears to be gold, which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC.
+The oldest gold artifacts in the world are from Bulgaria and are dating back to the 5th millennium BC (4,600 BC to 4,200 BC), such as those found in the Varna Necropolis near Lake Varna and the Black Sea coast, thought to be the earliest "well-dated" finding of gold artifacts in history.
+Gold artifacts probably made their first appearance in Ancient Egypt at the very beginning of the pre-dynastic period, at the end of the fifth millennium BC and the start of the fourth, and smelting was developed during the course of the 4th millennium; gold artifacts appear in the archeology of Lower Mesopotamia during the early 4th millennium. As of 1990, gold artifacts found at the Wadi Qana cave cemetery of the 4th millennium BC in West Bank were the earliest from the Levant. Gold artifacts such as the golden hats and the Nebra disk appeared in Central Europe from the 2nd millennium BC Bronze Age.
+The oldest known map of a gold mine was drawn in the 19th Dynasty of Ancient Egypt (1320–1200 BC), whereas the first written reference to gold was recorded in the 12th Dynasty around 1900 BC. Egyptian hieroglyphs from as early as 2600 BC describe gold, which King Tushratta of the Mitanni claimed was "more plentiful than dirt" in Egypt. Egypt and especially Nubia had the resources to make them major gold-producing areas for much of history. One of the earliest known maps, known as the Turin Papyrus Map, shows the plan of a gold mine in Nubia together with indications of the local geology. The primitive working methods are described by both Strabo and Diodorus Siculus, and included fire-setting. Large mines were also present across the Red Sea in what is now Saudi Arabia.
+Gold is mentioned in the Amarna letters numbered 19 and 26 from around the 14th century BC.
+Gold is mentioned frequently in the Old Testament, starting with Genesis 2:11 (at Havilah), the story of the golden calf, and many parts of the temple including the Menorah and the golden altar. In the New Testament, it is included with the gifts of the magi in the first chapters of Matthew. The Book of Revelation 21:21 describes the city of New Jerusalem as having streets "made of pure gold, clear as crystal". An ancient Talmudic text circa 100 AD describes Rachel, wife of Rabbi Akiva, receiving a "Jerusalem of Gold" (diadem).
+
+=== Classical Antiquity ===
+Exploitation of gold in the south-east corner of the Black Sea is said to date from the time of Midas, and this gold was important in the establishment of what is probably the world's earliest coinage in Lydia around 610 BC. The legend of the Golden Fleece dating from eighth century BC may refer to the use of fleeces to trap gold dust from placer deposits in the ancient world. From the 6th or 5th century BC, the Chu (state) circulated the Ying Yuan, one kind of square gold coin.
+In Roman metallurgy, new methods for extracting gold on a large scale were developed by introducing hydraulic mining methods, especially in Hispania from 25 BC onwards and in Dacia from 106 AD onwards. One of their largest mines was at Las Medulas in León, where seven long aqueducts enabled them to sluice most of a large alluvial deposit. The mines at Roşia Montană in Transylvania were also very large, and until very recently, still mined by opencast methods. They also exploited smaller deposits in Britain, such as placer and hard-rock deposits at Dolaucothi. The various methods they used are well described by Pliny the Elder in his encyclopedia Naturalis Historia written towards the end of the first century AD.
+A Greek burial crown made of gold was found in a grave circa 370 BC.
+
+=== Middle Ages ===
+During Mansa Musa's (ruler of the Mali Empire from 1312 to 1337) hajj to Mecca in 1324, he passed through Cairo in July 1324, and was reportedly accompanied by a camel train that included thousands of people and nearly a hundred camels where he gave away so much gold that it depressed the price in Egypt for over a decade, causing high inflation. A contemporary Arab historian remarked:

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+
+Gold was at a high price in Egypt until they came in that year. The mithqal did not go below 25 dirhams and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...].The Dome of the Rock is covered with an ultra-thin golden glassier. The Sikh Golden temple, the Harmandir Sahib, is a building covered with gold. Similarly the Wat Phra Kaew emerald Buddhist temple (wat) in Thailand has ornamental gold-leafed statues and roofs
+One main goal of the alchemists was to produce gold from other substances, such as lead — presumably by the interaction with a mythical substance called the philosopher's stone. Trying to produce gold led the alchemists to systematically find out what can be done with substances, and this laid the foundation for today's chemistry, which can produce gold (albeit uneconomically) by using nuclear transmutation. Their symbol for gold was the circle with a point at its center (☉), which was also the astrological symbol and the ancient Chinese character for the Sun.
+
+=== In the Americas ===
+
+The European exploration of the Americas was fueled in no small part by reports of the gold ornaments displayed in great profusion by Native American peoples, especially in Mesoamerica, Peru, Ecuador and Colombia. The Aztecs regarded gold as the product of the gods, calling it literally "god excrement" (teocuitlatl in Nahuatl), and after Moctezuma II was killed, most of this gold was shipped to Spain. However, for the indigenous peoples of North America gold was considered useless and they saw much greater value in other minerals which were directly related to their utility, such as obsidian, flint, and slate.
+El Dorado is applied to a legendary story in which precious stones were found in fabulous abundance along with gold coins. The concept of El Dorado underwent several transformations, and eventually accounts of the previous myth were also combined with those of a legendary lost city. El Dorado, was the term used by the Spanish Empire to describe a mythical tribal chief (zipa) of the Muisca native people in Colombia, who, as an initiation rite, covered himself with gold dust and submerged in Lake Guatavita. The legends surrounding El Dorado changed over time, as it went from being a man, to a city, to a kingdom, and then finally to an empire.
+The exploitation of gold in Colonial Brazil began at the end of the 17th century, especially in the region of Minas Gerais, and brought about profound economic, social, and administrative transformations. According to estimates by historians, between 800 and 1,000 tons of gold were extracted during the 18th and early 19th centuries. Gold mining attracted a large population flow, encouraged the occupation of the interior, and led to the emergence of towns and cities, sustained by enslaved labor, while also prompting the Portuguese Crown to strengthen oversight and tax collection, such as the quinto.
+
+=== European colonization of Africa ===
+Beginning in the early modern period, European exploration and colonization of West Africa was driven in large part by reports of gold deposits in the region, which was eventually referred to by Europeans as the "Gold Coast". From the late 15th to early 19th centuries, European trade in the region was primarily focused in gold, along with ivory and slaves. The gold trade in West Africa was dominated by the Ashanti Empire, who initially traded with the Portuguese before branching out and trading with British, French, Spanish and Danish merchants. British desires to secure control of West African gold deposits played a role in the Anglo-Ashanti wars of the late 19th century, which saw the Ashanti Empire annexed by Britain.
+
+== Culture ==
+
+In popular culture gold is a high standard of excellence, often used in awards. Great achievements are frequently rewarded with gold, in the form of gold medals, gold trophies and other decorations. Winners of athletic events and other graded competitions are usually awarded a gold medal. Many awards such as the Nobel Prize are made from gold as well. Other award statues and prizes are depicted in gold or are gold plated (such as the Academy Awards, the Golden Globe Awards, the Emmy Awards, the Palme d'Or, and the British Academy Film Awards). The top prize at the Olympic Games and many other sports competitions is the gold medal.
+Aristotle in his ethics used gold symbolism when referring to what is now known as the golden mean. Similarly, gold is associated with perfect or divine principles, such as in the case of the golden ratio and the Golden Rule. Gold is further associated with the wisdom of aging and fruition. The fiftieth wedding anniversary is golden. A person's most valued or most successful latter years are sometimes considered "golden years" or "golden jubilee". The height of a civilization is referred to as a golden age.
+Gold played a role in western culture, as a cause for desire and of corruption, as told in children's fables such as Rumpelstiltskin—where Rumpelstiltskin turns hay into gold for the peasant's daughter in return for her child when she becomes a princess—and the stealing of the hen that lays golden eggs in Jack and the Beanstalk.

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+
+== Price ==
+Historically gold coinage was widely used as currency; when paper money was introduced, it typically was a receipt redeemable for gold coin or bullion. In a monetary system known as the gold standard, a certain weight of gold was given the name of a unit of currency. For a long period, the United States government set the value of the US dollar so that one troy ounce was equal to $20.67 ($0.665 per gram, equivalent to $16 in 2025), but in 1934 the dollar was devalued to $35.00 per troy ounce ($0.889/g, equivalent to $21 in 2025). By 1961, it was becoming hard to maintain this price, and a pool of US and European banks agreed to manipulate the market to prevent further currency devaluation against increased gold demand.
+The largest gold depository in the world is that of the U.S. Federal Reserve Bank in New York, which holds about 3% of the gold known to exist and accounted for today, as does the similarly laden U.S. Bullion Depository at Fort Knox. In 2005 the World Gold Council estimated total global gold supply to be 3,859 tonnes and demand to be 3,754 tonnes, giving a surplus of 105 tonnes.
+After 15 August 1971 Nixon shock, the price began to greatly increase, and between 1968 and 2000 the price of gold ranged widely, from a high of $850 per troy ounce ($27.33/g, equivalent to $107 in 2025) on 21 January 1980, to a low of $252.90 per troy ounce ($8.13/g, equivalent to $16 in 2025) on 21 June 1999 (London Gold Fixing). Prices increased rapidly from 2001, but the 1980 high was not exceeded until 3 January 2008, when a new maximum of $865.35 per troy ounce was set (equivalent to $1,294 in 2025). Another record price was set on 17 March 2008, at $1023.50 per troy ounce ($32.91/g, equivalent to $49 in 2025).
+On 2 December 2009, gold reached a new high closing at $1,217.23 (equivalent to $1,827 in 2025). Gold further rallied hitting new highs in May 2010 after the European Union debt crisis prompted further purchase of gold as a safe asset. On 1 March 2011, gold hit a new all-time high of $1432.57 (equivalent to $2,050 in 2025), based on investor concerns regarding ongoing unrest in North Africa as well as in the Middle East.
+From April 2001 to August 2011, spot gold prices more than quintupled in value against the US dollar, hitting yet another new all-time high of $1,913.50 on 23 August 2011 (equivalent to $2,739 in 2025), prompting speculation that the long secular bear market had ended and a bull market had returned. However, the price then began a slow decline towards $1,200 per troy ounce in late 2014 and 2015 (equivalent to $1,632 in 2025).
+In August 2020, the gold price picked up to US$2,060 per ounce (equivalent to $2,563 in 2025) after a total growth of 59% from August 2018 to October 2020, a period during which it outplaced the Nasdaq total return of 54%.
+Gold futures are traded on the COMEX exchange. These contacts are priced in USD per troy ounce (1 troy ounce = 31.1034768 grams). Below are the CQG contract specifications outlining the futures contracts:
+
+== Religion ==
+
+The first known prehistoric human usages of gold were religious in nature.
+In some forms of Christianity and Judaism, gold has been associated both with the sacred and evil. In the Book of Exodus, the Golden Calf is a symbol of idolatry, while in the Book of Genesis, Abraham was said to be rich in gold and silver, and Moses was instructed to cover the Mercy Seat of the Ark of the Covenant with pure gold. In Byzantine iconography the halos of Christ, Virgin Mary and the saints are often golden.
+In Islam, gold (along with silk) is often cited as being forbidden for men to wear. Abu Bakr al-Jazaeri, quoting a hadith, said that "[t]he wearing of silk and gold are forbidden on the males of my nation, and they are lawful to their women". This, however, has not been enforced consistently throughout history, e.g. in the Ottoman Empire. Further, small gold accents on clothing, such as in embroidery, may be permitted.
+In ancient Greek religion and mythology, Theia was seen as the goddess of gold, silver and other gemstones.
+According to Christopher Columbus, those who had something of gold were in possession of something of great value on Earth and a substance to even help souls to paradise.
+Wedding rings are typically made of gold. It is long lasting and unaffected by the passage of time and may aid in the ring symbolism of eternal vows before God and the perfection the marriage signifies. In Orthodox Christian wedding ceremonies, the wedded couple is adorned with a golden crown (though some opt for wreaths, instead) during the ceremony, an amalgamation of symbolic rites.
+On 24 August 2020, Israeli archaeologists discovered a trove of early Islamic gold coins near the central city of Yavne. Analysis of the extremely rare collection of 425 gold coins indicated that they were from the late 9th century. Dating to around 1,100 years back, the gold coins were from the Abbasid Caliphate.
+
+== References ==
+
+== Further reading ==
+Bachmann, H. G. The lure of gold : an artistic and cultural history (2006) online
+Bernstein, Peter L. The Power of Gold: The History of an Obsession (2000) online
+Brands, H.W. The Age of Gold: The California Gold Rush and the New American Dream (2003) excerpt
+Buranelli, Vincent. Gold : an illustrated history (1979) online' wide-ranging popular history
+Cassel, Gustav. "The restoration of the gold standard." Economica 9 (1923): 171–185. online
+Eichengreen, Barry. Golden Fetters: The Gold Standard and the Great Depression, 1919–1939 (Oxford UP, 1992).
+Ferguson, Niall. The Ascent of Money – Financial History of the World (2009) online
+Hart, Matthew, Gold: The Race for the World's Most Seductive Metal Gold : the race for the world's most seductive metal", New York: Simon & Schuster, 2013. ISBN 9781451650020
+Johnson, Harry G (1969). "The gold rush of 1968 in retrospect and prospect". American Economic Review. 59 (2): 344–348. JSTOR 1823687.
+Kwarteng, Kwasi. War and Gold: A Five-Hundred-Year History of Empires, Adventures, and Debt (2014) online
+Vilar, Pierre. A History of Gold and Money, 1450–1920 (1960). online
+Vilches, Elvira. New World Gold: Cultural Anxiety and Monetary Disorder in Early Modern Spain (2010).
+
+== External links ==

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+title: "History of gunpowder"
+chunk: 1/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+Gunpowder is the first explosive to have been created in the world. Popularly listed as one of the "Four Great Inventions" of China, it was invented during the late Tang dynasty (9th century) while the earliest recorded chemical formula for gunpowder dates to the Song dynasty (11th century). Knowledge of gunpowder spread rapidly throughout Eurasia, possibly as a result of the Mongol conquests during the 13th century, with written formulas for it appearing in the Middle East between 1240 and 1280 in a treatise by Hasan al-Rammah, and in Europe by 1267 in the Opus Majus by Roger Bacon. It was employed in warfare to some effect from at least the 10th century in weapons such as fire arrows, bombs, and the fire lance before the appearance of the gun in the 13th century. While the fire lance was eventually supplanted by the gun, other gunpowder weapons such as rockets and fire arrows continued to see use in China, Korea, India, and this eventually led to its use in the Middle East, Europe, and Africa. Bombs too never ceased to develop and continued to progress into the modern day as grenades, mines, and other explosive implements. Gunpowder has also been used for non-military purposes such as fireworks for entertainment, or in explosives for mining and tunneling.
+The evolution of guns led to the development of large artillery pieces, popularly known as bombards, during the 15th century, pioneered by states such as the Duchy of Burgundy. Firearms came to dominate early modern warfare in Europe by the 17th century. The gradual improvement of cannons firing heavier rounds for a greater impact against fortifications led to the invention of the star fort and the bastion in the Western world, where traditional city walls and castles were no longer suitable for defense. The use of gunpowder technology also spread throughout the Islamic world and to India, Korea, and Japan. The so-called Gunpowder Empires of the early modern period consisted of the Mughal Empire, Safavid Empire, and Ottoman Empire.
+The use of gunpowder in warfare during the course of the 19th century diminished due to the invention of smokeless powder. Gunpowder is often referred to today as "black powder" to distinguish it from the propellant used in contemporary firearms.
+
+== Chinese beginnings ==

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+---
+title: "History of gunpowder"
+chunk: 2/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+=== Gunpowder formula ===
+Gunpowder was invented in China sometime during the first millennium AD. The earliest possible reference to gunpowder appeared in 142 AD during the Eastern Han dynasty when the alchemist Wei Boyang, also known as the "father of alchemy", wrote about a substance with gunpowder-like properties. He described a mixture of three powders that would "fly and dance" violently in his Cantong qi, otherwise known as the Book of the Kinship of Three, a Taoist text on the subject of alchemy. At this time, saltpeter was produced in Hanzhong, but would shift to Gansu and Sichuan later on. Wei Boyang is considered to be a semi-legendary figure meant to represent a "collective unity", and the Cantong qi was probably written in stages from the Han dynasty to 450 AD.
+While it was almost certainly not their intention to create a weapon of war, Taoist alchemists continued to play a major role in gunpowder development due to their experiments with sulfur and saltpeter involved in searching for eternal life and ways to transmute one material into another. Historian Peter Lorge notes that despite the early association of gunpowder with Taoism, this may be a quirk of historiography and a result of the better preservation of texts associated with Taoism, rather than being a subject limited to only Taoists. The Taoist quest for the elixir of life attracted many powerful patrons, one of whom was Emperor Wu of Han. One of the resulting alchemical experiments involved heating 10% sulfur and 75% saltpeter to transform them.
+The next reference to gunpowder occurred in the year 300 during the Jin dynasty (266–420). A Taoist philosopher by the name of Ge Hong wrote down the ingredients of gunpowder in his surviving works, collectively known as the Baopuzi ("The Master Who Embraces Simplicity"). The "Inner Chapters" (neipian) on Taoism contains records of his experiments to create gold with heated saltpeter, pine resin, and charcoal among other carbon materials, resulting in a purple powder and arsenic vapours. In 492, Taoist alchemists noted that saltpeter, one of the most important ingredients in gunpowder, burns with a purple flame, allowing for practical efforts at purifying the substance. During the Tang dynasty, alchemists used saltpeter in processing the "four yellow drugs" (sulfur, realgar, orpiment, arsenic trisulfide).
+The first confirmed references to what can be considered gunpowder in China occurred more than three hundred years later during the Tang dynasty in two Taoist texts. The first in a formula contained in the Taishang Shengzu Jindan Mijue (太上聖祖金丹秘訣) in 808, and then about 50 years later in a text known as the Zhenyuan miaodao yaolüe (真元妙道要略). The first formula was a combination of six parts sulfur to six parts saltpeter to one part birthwort herb. The second text warned against an assortment of dangerous formulas, one of which corresponds with gunpowder: "Some have heated together sulfur, realgar (arsenic disulfide),
+and saltpeter with honey; smoke [and flames] result, so that their hands and faces have been burnt, and even the whole house burned down." Alchemists called this discovery fire medicine ("huoyao" 火藥), and the term has continued to refer to gunpowder in China into the present day, a reminder of its heritage as a side result in the search for longevity increasing drugs. A book published in 1185 called Gui Dong (The Control of Spirits) also contains a story about a Tang dynasty alchemist whose furnace exploded, but it is not known if this was caused by gunpowder.
+The earliest surviving chemical formula of gunpowder dates to 1044 in the form of the military manual Wujing Zongyao, also known in English as the Complete Essentials for the Military Classics, which contains a collection of entries on Chinese weaponry. However the 1044 edition has since been lost and the only currently extant copy is dated to 1510 during the Ming dynasty. The Wujing Zongyao served as a repository of antiquated or fanciful weaponry, and this applied to gunpowder as well, suggesting that it had already been weaponized long before the invention of what would today be considered conventional firearms. These types of gunpowder weapons had an assortment of odd names such as "flying incendiary club for subjugating demons", "caltrop fire ball", "ten-thousand fire flying sand magic bomb", "big bees nest", "burning heaven fierce fire unstoppable bomb", and "fire bricks" which released "flying swallows", "flying rats", "fire birds", and "fire oxen". Eventually they gave way and coalesced into a smaller number of dominant weapon types, notably gunpowder arrows, bombs, and early guns. This was most likely because some weapons were deemed too onerous or ineffective to deploy.
+
+=== Fire arrows ===
+
+The early gunpowder formula contained too little saltpeter (about 50%) to be explosive, but the mixture was highly flammable, and contemporary weapons reflected this in their deployment as mainly shock and incendiary weapons. One of the first, if not the first of these weapons was the fire arrow. The first possible reference to the use of fire arrows was by the Southern Wu in 904 during the siege of Yuzhang. An officer under Yang Xingmi by the name of Zheng Fan (鄭璠) ordered his troops to "shoot off a machine to let fire and burn the Longsha Gate", after which he and his troops dashed over the fire into the city and captured it, and he was promoted to Prime Minister Inspectorate for his efforts and the burns his body endured. A later account of this event corroborated with the report and explained that "by let fire (飛火) is meant things like firebombs and fire arrows." Arrows carrying gunpowder were possibly the most applicable form of gunpowder weaponry at the time. Early gunpowder may have only produced an effective flame when exposed to oxygen, thus the rush of air around the arrow in flight would have provided a suitably ample supply of reactants for the reaction.

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+---
+title: "History of gunpowder"
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+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
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+---
+
+The Muslim world acquired the gunpowder formula some time after 1240, but before 1280, by which time Hasan al-Rammah had written, in Arabic, recipes for gunpowder, instructions for the purification of saltpeter, and descriptions of gunpowder incendiaries. Early Muslim sources suggest that knowledge of gunpowder was acquired from China and may have been introduced by invading Mongols. This is implied by al-Rammah's usage of "terms that suggested he derived his knowledge from Chinese sources." Early Arab texts on gunpowder refer to saltpeter as "Chinese snow" (Arabic: ثلج الصين thalj al-ṣīn), fireworks as "Chinese flowers" and rockets as "Chinese arrows" (sahm al-Khitai). Similarly, the Persians called saltpeter "Chinese salt" or "salt from Chinese salt marshes" (namak shūra chīnī Persian: نمک شوره چيني). Fireworks listed by al-Rammah include "wheels of China" and "flowers of China".
+The gunpowder formula of al-Rammah has a saltpeter content of 68% to 75%, which is more explosive than is necessary for rockets, however no explosives are mentioned. Al-Rammah's text, The Book of Military Horsemanship and Ingenious War Devices (Kitab al-Furusiya wa'l-Munasab al-Harbiya), does however mention fuses, incendiary bombs, naphtha pots, fire lances, and an illustration and description of the earliest torpedo. The torpedo was called the "egg which moves itself and burns." Two iron sheets were fastened together and tightened using felt. The flattened pear shaped vessel was filled with gunpowder, metal filings, "good mixtures," two rods, and a large rocket for propulsion. Judging by the illustration, it was evidently supposed to glide across the water.
+Hasan al-Rammah was the first Muslim to describe the purification of saltpeter using the chemical processes of solution and crystallization. This was the first clear method for the purification of saltpeter.
+According to Joseph Needham, fire lances were used in battles between the Muslims and Mongols in 1299 and 1303.
+The earliest surviving documentary evidence for cannons in the Islamic world is from an Arabic manuscript dated to the early 14th century. The author's name is uncertain but may have been Shams al-Din Muhammad, who died in 1350. Dating from around 1320–1350, the illustrations show gunpowder weapons such as gunpowder arrows, bombs, fire tubes, and fire lances or proto-guns. The manuscript describes a type of gunpowder weapon called a midfa which uses gunpowder to shoot projectiles out of a tube at the end of a stock. Some consider this to be a cannon while others do not. The problem with identifying cannons in early 14th century Arabic texts is the term midfa, which appears from 1342 to 1352 but cannot be proven to be true hand-guns or bombards. Contemporary accounts of a metal-barrel cannon in the Islamic world do not occur until 1365. Needham believes that in its original form the term midfa refers to the tube or cylinder of a naphtha projector (flamethrower), then after the invention of gunpowder it meant the tube of fire lances, and eventually it applied to the cylinder of hand-gun and cannon.
+
+Description of the drug (mixture) to be introduced in the madfa'a (cannon) with its proportions: barud, ten; charcoal two drachmes, sulphur one and a half drachmes. Reduce the whole into a thin powder and fill with it one third of the madfa'a. Do not put more because it might explode. This is why you should go to the turner and ask him to make a wooden madfa'a whose size must be in proportion with its muzzle. Introduce the mixture (drug) strongly; add the bunduk (balls) or the arrow and put fire to the priming. The madfa'a length must be in proportion with the hole. If the madfa'a was deeper than the muzzle's width, this would be a defect. Take care of the gunners. Be careful
+According to Paul E. J. Hammer, the Mamluks certainly used cannons by 1342. According to J. Lavin, cannons were used by Moors at the siege of Algeciras in 1343. A metal cannon firing an iron ball was described by Shihab al-Din Abu al-Abbas al-Qalqashandi between 1365 and 1376.
+
+=== Europe ===

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+---
+title: "History of gunpowder"
+chunk: 12/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
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+---
+
+A common theory of how gunpowder came to Europe is that it made its way along the Silk Road through the Middle East. Another is that it was brought to Europe during the Mongol invasion in the first half of the 13th century. Some sources claim that Chinese firearms and gunpowder weapons may have been deployed by Mongols against European forces at the Battle of Mohi in 1241. It may also have been due to subsequent diplomatic and military contacts. Some authors have speculated that William of Rubruck, who served as an ambassador to the Mongols from 1253 to 1255, was a possible intermediary in the transmission of gunpowder. His travels were recorded by Roger Bacon, who was the first European to mention gunpowder, but the records of William's journey do not contain any mention of gunpowder.
+The earliest European references to gunpowder are found in Roger Bacon's Opus Majus from 1267, in which he mentions a firecracker toy found in various parts of the world. The passage reads: "We have an example of these things (that act on the senses) in [the sound and fire of] that children's toy which is made in many [diverse] parts of the world; i.e., a device no bigger than one's thumb. From the violence of that salt called saltpeter [together with sulfur and willow charcoal, combined into a powder] so horrible a sound is made by the bursting of a thing so small, no more than a bit of parchment [containing it], that we find [the ear assaulted by a noise] exceeding the roar of strong thunder, and a flash brighter than the most brilliant lightning." In the early 20th century, British artillery officer Henry William Lovett Hime proposed that another work tentatively attributed to Bacon, Epistola de Secretis Operibus Artis et Naturae, et de Nullitate Magiae contained an encrypted formula for gunpowder. This claim has been disputed by historians of science including Lynn Thorndike, John Maxson Stillman and George Sarton and by Bacon's editor Robert Steele, both in terms of authenticity of the work, and with respect to the decryption method. In any case, the formula claimed to have been decrypted (7:5:5 saltpeter:charcoal:sulfur) is not useful for firearms use or even firecrackers, burning slowly and producing mostly smoke. However, if Bacon's recipe is taken as measurements by volume rather than weight, a far more potent and serviceable explosive powder is created suitable for firing hand-cannons, albeit less consistent due to the inherent inaccuracies of measurements by volume. One example of this composition resulted in 100 parts saltpeter, 27 parts charcoal, and 45 parts sulfur, by weight.
+The oldest written recipes for gunpowder in Europe were recorded under the name Marcus Graecus or Mark the Greek between 1280 and 1300 in the Liber Ignium, or Book of Fires. One recipe for "flying fire" (ignis volatilis) involves saltpeter, sulfur, and colophonium, which, when inserted into a reed or hollow wood, "flies away suddenly and burns up everything." Another recipe, for artificial "thunder", specifies a mixture of one pound native sulfur, two pounds linden or willow charcoal, and six pounds of saltpeter. Another specifies a 1:3:9 ratio. The text is likely a translation from Arabic through a Spanish intermediary due to the terminology used and recipes for items found in 12th century Arabic texts.
+The earliest known European depiction of a gun appeared in 1326 in a manuscript by Walter de Milemete, although not necessarily drawn by him, known as De Nobilitatibus, sapientii et prudentiis regum (Concerning the Majesty, Wisdom, and Prudence of Kings), which displays a gun with a large arrow emerging from it and its user lowering a long stick to ignite the gun through the touchole In the same year, another similar illustration showed a darker gun being set off by a group of knights, which also featured in another work of de Milemete's, De secretis secretorum Aristotelis. On 11 February of that same year, the Signoria of Florence appointed two officers to obtain canones de mettallo and ammunition for the town's defense. In the following year a document from the Turin area recorded a certain amount was paid "for the making of a certain instrument or device made by Friar Marcello for the projection of pellets of lead." The bronze vase-shaped gun from Mantua, unfortunately disappeared in 1849, but of which we have drawings and measurements taken in 1786, dates back to 1322. It was 16.4 cm long, weighed about 5 kg and had a caliber of 5.5 cm.
+The 1320s seem to have been the takeoff point for guns in Europe according to most modern military historians. Scholars suggest that the lack of gunpowder weapons in a well-traveled Venetian's catalogue for a new crusade in 1321 implies that guns were unknown in Europe up until this point. From the 1320s guns spread rapidly across Europe. The French raiding party that sacked and burned Southampton in 1338 brought with them a ribaudequin and 48 bolts (but only 3 pounds of gunpowder). By 1341 the town of Lille had a "tonnoire master," and a tonnoire was an arrow-hurling gun. In 1345, two iron cannons were present in Toulouse. In 1346 Aix-la-Chapelle too possessed iron cannons which shot arrows (busa ferrea ad sagittandum tonitrum). The Battle of Crécy in 1346 was one of the first in Europe where cannons were used. By 1350 Petrarch wrote that the presence of cannons on the battlefield was 'as common and familiar as other kinds of arms'.
+Around the late 14th century European and Ottoman guns began to deviate in purpose and design from guns in China, changing from small anti-personnel and incendiary devices to the larger artillery pieces most people imagine today when using the word "cannon." If the 1320s can be considered the arrival of the gun on the European scene, then the end of the 14th century may very well be the departure point from the trajectory of gun development in China. In the last quarter of the 14th century, European guns grew larger and began to blast down fortifications.

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+---
+title: "History of gunpowder"
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+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+=== Southeast Asia ===
+
+In Southeast Asia, cannons were used by the Ayutthaya Kingdom in 1352 during its invasion of the Khmer Empire. Within a decade large quantities of gunpowder could be found in the Khmer Empire. By the end of the century firearms were also used by the Trần dynasty in Đại Việt.
+The Mongol invasion of Java in 1293 brought gunpowder technology to the Nusantara archipelago in the form of cannon (Chinese: 炮—Pào). The knowledge of making gunpowder-based weapon has been known after the failed Mongol invasion of Java. The predecessor of firearms, the pole gun (bedil tombak), was recorded as being used in Java by 1413, while the knowledge of making "true" firearms came much later, after the middle of 15th century. It was brought by the Muslim traders from West Asia, most probably the Arabs. The precise year of introduction is unknown, but it may be safely concluded to be no earlier than 1460.
+Portuguese influence to local weaponry after the capture of Malacca (1511) resulted in a new type of hybrid tradition matchlock firearm, the istinggar. Saltpeter harvesting was recorded by Dutch and German travelers as being common in even the smallest villages and was collected from the decomposition process of large dung hills specifically piled for this purpose. The Dutch punishment for possession of non-permitted gunpowder appears to have been amputation. Ownership and manufacture of gunpowder was later prohibited by the colonial Dutch occupiers. According to colonel McKenzie quoted in the book The History of Java (1817) by Thomas Stamford Raffles, the purest sulfur was supplied from a crater from a mountain near the straits of Bali.
+
+=== India ===
+Gunpowder technology is believed to have arrived in India by the mid-14th century, but could have been introduced much earlier by the Mongols, who had conquered both China and some borderlands of India, perhaps as early as the mid-13th century. The unification of a large single Mongol Empire resulted in the free transmission of Chinese technology into Mongol conquered parts of India. Regardless, it is believed that the Mongols used Chinese gunpowder weapons during their invasions of India. It was written in the Tarikh-i Firishta (1606–1607) that the envoy of the Mongol ruler Hulegu Khan was presented with a dazzling pyrotechnics display upon his arrival in Delhi in 1258. The first gunpowder device, as opposed to naphtha-based pyrotechnics, introduced to India from China in the second half of the 13th century, was a rocket called the "hawai" (also called "ban"). The rocket was used as an instrument of war from the second half of the 14th century onward, and the Delhi sultanate as well as the Bahmani Sultanate made good use of them. As a part of an embassy to India by Timurid leader Shah Rukh (1405–1447), 'Abd al-Razzaq mentioned naphtha-throwers mounted on elephants and a variety of pyrotechnics put on display. Roger Pauly has written that "while gunpowder was primarily a Chinese innovation," the saltpeter that led to the invention of gunpowder may have arrived from India, although it is also likely that it originated indigenously in China.
+Firearms known as top-o-tufak also existed in the Vijayanagara Empire of Southern India by as early as 1366. In 1368–1369, the Bahmani Sultanate may have used firearms against Vijayanagara, but these weapons could have been pyrotechnics as well. By 1442 guns had a clearly felt presence in India as attested to by historical records. From then on the employment of gunpowder warfare in India was prevalent, with events such as the siege of Belgaum in 1473 by Muhammad Shah III. Muslim and Hindu states in the south were advanced in artillery compared to the Delhi rulers of this period because of their contact with the outside world, especially Ottomans, through the sea route. The south Indian kingdoms imported their gunners (topci) and artillery from Turkey and the Arab countries, with whom they had developed good relations.
+
+=== Korea ===
+
+Korea had already come into possession of cannons by 1373, when a Korean mission was sent to China requesting gunpowder supplies for the artillery on their ships. However Korea did not natively produce gunpowder until the years 1374–76. In the 14th century a Korean scholar named Ch'oe Mu-sŏn discovered a way to produce it after visiting China and bribing a merchant by the name of Li Yuan for the gunpowder formula. In 1377 he figured out how to extract potassium nitrate from the soil and subsequently invented the juhwa, Korea's first rocket, and further developments led to the birth of singijeons, Korean arrow rockets. Korea also began producing cannons in 1377. The multiple rocket launcher known as hwacha ("fire cart" 火車) was developed from the juhwa and singijeon in Korea by 1409 during the Joseon Dynasty. Its inventors include Yi To (이도, not to be mistaken for Sejong the Great) and Ch'oe Hae-san, the son of Ch'oe Mu-sŏn. However the first hwachas did not fire rockets, but used mounted bronze guns that shot iron-fletched darts. Rocket launching hwachas were developed in 1451 under the decree of King Munjong and his younger brother Pe. ImYung (Yi Gu, 임영대군 이구). This "Munjong Hwacha" is the well-known type today, and could fire 100 rocket arrows or 200 small Chongtong bullets at one time with changeable modules. At the time, 50 units were deployed in Hanseong (present-day Seoul), and another 80 on the northern border. By the end of 1451, hundreds of hwachas were deployed throughout Korea.
+Naval gunpowder weapons also appeared and were rapidly adopted by Korean ships for conflicts against Japanese pirates in 1380 and 1383. By 1410, 160 Korean ships were reported to have equipped artillery of some sort. Mortars firing thunder-crash bombs are known to have been used, and four types of cannons are mentioned: chonja (heaven), chija (earth), hyonja (black), and hwangja (yellow), but their specifications are unknown. These cannons typically shot wooden arrows tipped with iron, the longest of which were nine feet long, but stone and iron balls were sometimes used as well.

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+---
+title: "History of gunpowder"
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+category: "reference"
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+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+=== Japan ===
+
+Firearms seem to have been known in Japan around 1270 as proto-cannons invented in China, which the Japanese called teppō (鉄砲 lit. "iron cannon"). Gunpowder weaponry exchange between China and Japan was slow and only a small number of hand guns ever reached Japan. However Japanese samurai used Fire lances in 15th-century. The first recorded appearance of the Fire lances in Japan was in 1409. The use of gunpowder bombs in the style of Chinese explosives is known to have occurred in Japan from at least the mid-15th century onward. The first recorded appearance of the cannon in Japan was in 1510 when a Buddhist monk presented Hōjō Ujitsuna with a teppō iron cannon that he had acquired during his travels in China. Firearms saw very little use in Japan until Portuguese matchlocks were introduced in 1543. During the Japanese invasions of Korea (1592–1598), the forces of Toyotomi Hideyoshi effectively used matchlock firearms against the Korean forces of Joseon, although they would ultimately be defeated and forced to withdraw from the Korean peninsula.
+
+=== Africa ===
+In Africa, the Adal Empire and the Abyssinian Empire both deployed gunpowder weapons during the Adal-Abyssinian War. Imported from Arabia, and the wider Islamic world, the Adalites, led by Ahmed ibn Ibrahim al-Ghazi, were the first African power to introduce cannon warfare to the African continent. Later on as the Portuguese Empire entered the war it would supply and train the Abyssinians with cannon and muskets, while the Ottoman Empire sent soldiers and cannon to back Adal. The conflict proved, through their use on both sides, the value of firearms such as the matchlock musket, cannon, and the arquebus over traditional weapons.
+Ernest Gellner in his book 'Nations and Nationalism' argues that the centralizing potential of the gun and the book, enabled both the Somali people and the Amhara people to dominate the political history of a vast area in Africa, despite neither of them being numerically predominant.
+
+"In the Horn of Africa both the Amharas and the Somalis possessed both gun and Book (not the same Book, but rival and different editions), and neither bothered greatly with the wheel. Each of these ethnic groups was aided in its use of these two pieces of cultural equipment by its link to other members of the wider religious civilization which habitually used them, and were willing to replenish their stock." – Ernest Gellner
+
+== Transition to early modern warfare ==
+
+=== Early Ming firearms ===
+
+Gun development and proliferation in China continued under the Ming dynasty. The success of its founder Zhu Yuanzhang, who declared his reign to be the era of Hongwu, or "Great Martiality," has often been attributed to his effective use of guns.
+Most early Ming guns weighed two to three kilograms while guns considered "large" at the time weighed around only seventy-five kilograms. Ming sources suggest guns such as these shot stones and iron balls, but were primarily used against men rather than for causing structural damage to ships or walls. Accuracy was low and they were limited to a range of only 50 paces or so.
+Despite the relatively small size of early Ming guns, some elements of gunpowder weapon design followed world trends. The growing length to muzzle bore ratio matched the rate at which European guns were developing up until the 1450s. The practice of corning gunpowder had been developed by 1370 for the purpose of increasing explosive power in land mines, and was arguably used in guns as well according to one record of a fire-tube shooting a projectile 457 meters, which was probably only possible at the time with the usage of corned powder. Around the same year Ming guns transitioned from using stone shots to iron ammunition, which has greater density and increased firearm power. Aside from firearms, the Ming pioneered in the usage of rocket launchers known as "wasp nests", which it manufactured for the army in 1380 and was used by the general Li Jinglong in 1400 against Zhu Di, the future Yongle Emperor.
+The peak of Chinese cannon development prior to the incorporation of European weaponry in the 16th century is exemplified by the muzzle loading wrought iron "great general cannon" (大將軍炮) which weighed up to 360 kilograms and could fire a 4.8 kilogram lead ball. Its heavier variant, the "great divine cannon" (大神銃), could weigh up to 600 kilograms and was capable of firing several iron balls and upward of a hundred iron shots at once. The great general and divine cannons were the last indigenous Chinese cannon designs prior to the incorporation of European models in the 16th century.
+The lack of larger siege weapons in China unlike the rest of the world where cannons grew larger and more potent has been attributed to the immense thickness of traditional Chinese walls, which Tonio Andrade suggests provided no incentive for creating larger cannons, since even industrial artillery had trouble overcoming them. Asianist Kenneth Chase also argues that larger guns were not particularly useful against China's traditional enemies: horse nomads.
+
+=== Big guns ===

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+title: "History of gunpowder"
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+
+The development of large artillery pieces began by Burgundy. Originally a minor power, the duchy grew to become one of the most powerful states in 14th-century Europe, and a great innovator in siege warfare. The Duke of Burgundy, Philip the Bold (1363–1404), based his power on the effective use of big guns and promoted research and development in all aspects of gunpowder weaponry technology. Philip established manufacturers and employed more cannon casters than any European power before him.
+Whereas most European guns before 1370 weighed about 20 to 40 lbs (9–14 kg), the French siege of Château de Saint-Sauveur-le-Vicomte in 1375 during the Hundred Years War saw the use of guns weighing over a ton (900 kg), firing stone balls weighing over 100 lbs (45 kg). Philip used large guns to help the French capture the fortress of Odruik in 1377. These guns fired projectiles far larger than any that had been used before, with seven guns that could shoot projectiles as heavy as 90 kilograms. The cannons smashed the city walls, inaugurating a new era of artillery warfare and Burgundy's territories rapidly expanded.
+Europe entered an arms race to build ever larger artillery pieces. By the early 15th century both French and English armies were equipped with larger pieces known as bombards, weighing up to 5 tons (4,535 kg) and firing balls weighing up to 300 lbs (136 kg). The artillery trains used by Henry V of England in the 1415 Siege of Harfleur and 1419 Siege of Rouen proved effective in breaching French fortifications, while artillery contributed to the victories of French forces under Joan of Arc in the Loire Campaign (1429).
+These weapons were transformational for European warfare. A hundred years earlier the Frenchman Pierre Dubois wrote that a "castle can hardly be taken within a year, and even if it does fall, it means more expenses for the king's purse and for his subjects than the conquest is worth," but by the 15th century European walls fell with the utmost regularity.
+The Ottoman Empire was also developing their own artillery pieces. Mehmed the Conqueror (1432–1481) was determined to procure large cannons for the purpose of conquering Constantinople. Hungarian Urban produced for him a six-meter (20-foot) long cannon, which required hundreds of pounds of gunpowder to fire; during the actual siege of Constantinople the gun proved to be somewhat underwhelming. However, dozens of other large cannons bombarded Constantinople's walls in their weakest sections for 55 days, and despite a fierce defense, the city's fortifications were overwhelmed.
+
+==== Changes to fortifications ====
+
+As a response to gunpowder artillery, European fortifications began displaying architectural principles such as lower and thicker walls in the mid-1400s. Cannon towers were built with artillery rooms where cannons could discharge fire from slits in the walls. However this proved problematic as the slow rate of fire, reverberating concussions, and noxious fumes produced greatly hindered defenders. Gun towers also limited the size and number of cannon placements because the rooms could only be built so big. Notable surviving artillery towers include a seven layer defensive structure built in 1480 at Fougères in Brittany, and a four layer tower built in 1479 at Querfurth in Saxony.
+The star fort, also known as the bastion fort, tracé à l'italienne, or renaissance fortress, was a style of fortification that became popular in Europe during the 16th century. The bastion and star fort was developed in Italy, where the Florentine engineer Giuliano da Sangallo (1445–1516) compiled a comprehensive defensive plan using the geometric bastion and full tracé à l'italienne that became widespread in Europe.
+The main distinguishing features of the star fort were its angle bastions, each placed to support their neighbor with lethal crossfire, covering all angles, making them extremely difficult to engage with and attack. Angle bastions consisted of two faces and two flanks. Artillery positions positioned at the flanks could fire parallel into the opposite bastion's line of fire, thus providing two lines of cover fire against an armed assault on the wall, and preventing mining parties from finding refuge. Meanwhile, artillery positioned on the bastion platform could fire frontally from the two faces, also providing overlapping fire with the opposite bastion. Overlapping mutually supporting defensive fire was the greatest advantage enjoyed by the star fort. As a result, sieges lasted longer and became more difficult affairs. By the 1530s the bastion fort had become the dominant defensive structure in Italy.
+Outside Europe, the star fort became an "engine of European expansion", and acted as a force multiplier so that small European garrisons could hold out against numerically superior forces. Wherever star forts were erected the natives experienced great difficulty in uprooting European invaders.
+In China, Sun Yuanhua advocated for the construction of angled bastion forts in his Xifashenji so that their cannons could better support each other. The officials Han Yun and Han Lin noted that cannons on square forts could not support each side as well as bastion forts. Their efforts to construct bastion forts and their results were inconclusive. Ma Weicheng built two bastion forts in his home county, which helped fend off a Qing incursion in 1638. By 1641, there were ten bastion forts in the county. Before bastion forts could be spread any further, the Ming dynasty fell in 1644, and they were largely forgotten as the Qing dynasty was on the offensive most of the time and had no use for them.

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+title: "History of gunpowder"
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+category: "reference"
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+date_saved: "2026-05-05T16:15:19.654773+00:00"
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+---
+
+=== Classical cannon ===
+Gun development and design in Europe reached its "classic" form in the 1480s – longer, lighter, more efficient, and more accurate compared to its predecessors only three decades prior. The design persisted, and cannons of the 1480s show little difference and surprising similarity with cannons three centuries later in the 1750s. This 300-year period during which the classic cannon dominated gives it its moniker.
+The early classical European guns are exemplified by two cannons from 1488 now preserved in a plaza in Neuchâtel, Switzerland. The Neuchâtel guns are 224 centimeters long, with a bore of 6.2 centimeters and the other is slightly longer, 252 centimeters, with the same bore size. They are differentiated from older firearms by an assortment of improvements. Their longer length-to-bore ratio imparts more energy into the shot, enabling the projectile to shoot further. Not only longer, they were also lighter as the barrel walls were made thinner to allow for faster dissipation of heat. They also no longer needed the help of a wooden plug to load since they offered a tighter fit between projectile and barrel, further increasing the accuracy of gunpowder warfare – and were deadlier due to developments such as gunpowder corning and iron shot. When these guns reached China in the 1510s, the Chinese were highly impressed by them, primarily for their longer and thinner barrels.
+The two primary theories for the appearance of the classic gun involve the development of gunpowder corning and a new method for casting guns.
+The corning hypothesis stipulates that the longer barrels came about as a reaction to the development of corned gunpowder. Not only did "corned" powder keep better, because of its reduced surface area, but gunners also found that it was more powerful and easier to load into guns. Prior to corning, gunpowder would also frequently demix into its constitutive components and was therefore unreliable. The faster gunpowder reaction was suitable for smaller guns, since large ones had a tendency to crack, and the more controlled reaction allowed large guns to have longer, thinner walls. However, the corning hypothesis has been argued against on two grounds: One, the powder makers were probably more worried about spoilage than the effect of corned gunpowder on guns; and two, corning as a practice had existed in China (for explosives) since the 1370s.
+The second theory is that the key to developing the classic gun may have been a new method of gun casting, muzzle side up. Smith observes: "The surviving pieces of ordnance from earlier in the 15th century are big pieces with large bore sizes. They do not look like the long thin gun.… Essentially they are parallel-sided tubes with flat ends. The explanation is, probably, that they were cast muzzle down in the traditional bell-founding method whereas the long thin guns were cast muzzle up.… Perhaps this marks the real 'revolution' in artillery. Once the technique of casting muzzle up with the attendant advantages, and it is not clear what those are at present, had been mastered by cannon founders, the way was open for the development of the 'classic' form of artillery." However, Smith himself states that it is not clear what advantages this technique would have conferred, despite its widespread adoption.
+
+==== Iron and bronze ====
+Across the 15th and 16th centuries there were primarily two different types of manufactured cannons. The wrought iron cannon and the cast-bronze cannon. Wrought iron guns were structurally composed of two layers: an inner tube of iron staves held together in a tight fit by an outer case of iron hoops. Bronze cannons on the other hand were cast in one piece similar to bells. The technique used in casting bronze cannons was so similar to the bell that the two were often looked upon as a connected enterprise.
+Both iron and bronze cannons had their advantages and disadvantages. Forged iron cannons were up to ten times cheaper, but more unstable due to their piece built nature. Even without use, iron cannons were liable to rust away, while bronze cannons did not. Another reason for the dominance of bronze cannons was their aesthetic appeal. Because cannons were so important as displays of power and prestige, rulers liked to commission bronze cannons, which could be sculpted into fanciful designs containing artistic motifs or symbols. It was for all these reasons that the cast-bronze cannon became the preferred type by the late 1400s.
+Some cannons cast in China during the 1370s may have been of steel rather than iron.
+
+==== Composite metal ====
+Composite iron/bronze cannons were far less common, but were produced in substantial numbers during the Ming and Qing dynasties. The resulting bronze-iron composite cannons were superior to iron or bronze cannons in many respects. They were lighter, stronger, longer lasting, and able to withstand more intensive explosive pressure. Chinese artisans also experimented with other variants such as cannons featuring wrought iron cores with cast iron exteriors. While inferior to their bronze-iron counterparts, these were considerably cheaper and more durable than standard iron cannons. Both types were met with success and were considered "among the best in the world" during the 17th century. The Chinese composite metal casting technique was effective enough that Portuguese imperial officials sought to employ Chinese gunsmiths for their cannon foundries in Goa, so that they could impart their methods for Portuguese weapons manufacturing. The Gujarats experimented with the same concept in 1545, the English at least by 1580, and Hollanders in 1629. However the effort required to produce these weapons prevented them from mass production. The Europeans essentially treated them as experimental products, resulting in very few surviving pieces today. Of the currently known extant composite metal cannons, there are 2 English, 2 Dutch, 12 Gujarati, and 48 from the Ming-Qing period.
+
+=== Arquebus and musket ===

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+---
+title: "History of gunpowder"
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+
+The average Mamluk archer for example was capable of hitting targets only 68 meters far away but could keep up a pace of six to eight shots per minute. In comparison, sixteenth-century matchlocks fired off one shot every several minutes, and much less when taking into consideration misfires and malfunctions which occurred up to half the time. This is not to say that firearms of the 16th century were inferior to the bow and arrow, for it could better penetrate armor and required less training, but the disadvantages of the musket were very real, and it would not be until the 1590s that archers were for the most part phased out of European warfare. This was possibly a consequence of the increased effectiveness of musket warfare due to the rise of volley fire in Europe as first applied by the Dutch. At this time gunners in European armies reached as high as 40 percent of infantry forces. As the virtues of the musket became apparent it was quickly adopted throughout Eurasia so that by 1560 even in China generals were giving praise to the new weapon. Qi Jiguang, a noted partisan of the musket, gave a eulogy on the effectiveness of the gun in 1560:

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+title: "History of gunpowder"
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+
+It is unlike any other of the many types of fire weapons. In strength it can pierce armor. In accuracy it can strike the center of targets, even to the point of hitting the eye of a coin [i.e., shooting right through a coin], and not just for exceptional shooters.… The arquebus [鳥銃] is such a powerful weapon and is so accurate that even bow and arrow cannot match it, and … nothing is so strong as to be able to defend against it.
+Other East Asian powers such as Đại Việt also adopted the matchlock musket in quick order. Đại Việt in particular was considered by the Ming to have produced the most advanced matchlocks in the world during the 17th century, surpassing even Ottoman, Japanese, and European firearms. European observers of the Trịnh–Nguyễn War also corroborated with the Ming in the proficiency of matchlock making by the Vietnamese. The Vietnamese matchlock was said to have been able to pierce several layers of iron armour, kill two to five men in one shot, yet also fire quietly for a weapon of its caliber.
+
+== Gunpowder Empires ==
+
+The Gunpowder Empires generally refer to the Islamic Ottoman, Safavid and Mughal empires. The phrase was first coined by Marshall Hodgson in the title of Book 5 ("The Second Flowering: The Empires of Gunpowder Times") of his highly influential three-volume work, The Venture of Islam (1974).
+Hogdson applied the term "gunpowder empire" to three Islamic political entities he identified as separate from the unstable, geographically limited confederations of Turkic clans that prevailed in post-Mongol times. He called them "military patronage states of the Later Middle Period," which possessed three defining characteristics: first, a legitimization of independent dynastic law; second, the conception of the whole state as a single military force; third, the attempt to explain all economic and high cultural resources as appanages of the chief military families. Connecting these empires were their traditions which grew "out of Mongol notions of greatness," but "[s]uch notions could fully mature and create stable bureaucratic empires only after gunpowder weapons and their specialized technology attained a primary place in military life."
+William H. McNeill further expanded on the concept of gunpowder empires by arguing that such states "were able to monopolize the new artillery, central authorities were able to unite larger territories into new, or newly consolidated, empires."
+In 2011 Douglas E. Streusand criticized the Hodgson-McNeill Gunpowder-Empire hypothesis, calling it into disfavor as a neither "adequate [n]or accurate" explanation, although the term remains in use. The main problem he saw with the Hodgson-McNeill theory is that the acquisition of firearms does not seem to have preceded the initial acquisition of territory constituting the imperial critical mass of any of the three early modern Islamic empires, except in the case of the Mughals. Moreover, it seems that the commitment to military autocratic rule pre-dated the acquisition of gunpowder weapons in all three cases.
+Whether or not gunpowder was inherently linked to the existence of any of these three empires, it cannot be questioned that each of the three acquired artillery and firearms early in their history and made such weapons an integral part of their military tactics.
+
+=== Ottoman Empire ===
+It's not certain when the Ottomans started using firearms, however it's argued that they had been using cannons since the Battles of Kosovo (1389) and Nukap (1396) and most certainly by the 1420s. Some argue that field guns only entered service shortly after the Battle of Varna (1444) and more certainly used in the Second Battle of Kosovo (1448). Firearms, (especially grenades) were used in the 1683 siege of Vienna The arquebus reached them around 1425.
+
+=== India and the Mughal Empire ===
+
+In India, guns made of bronze were recovered from Calicut (1504) and Diu (1533). By the 17th century, Indians were manufacturing a diverse variety of firearms; large guns in particular, became visible in Tanjore, Dacca, Bijapur and Murshidabad. Gujarāt supplied Europe saltpeter for use in gunpowder warfare during the 17th century. Bengal and Mālwa participated in saltpeter production. The Dutch, French, Portuguese, and English used Chāpra as a center of saltpeter refining.
+Fathullah Shirazi (c. 1582), who worked for Akbar the Great as a mechanical engineer, developed an early multi gun shot. Shirazi's rapid-firing gun had multiple gun barrels that fired hand cannons loaded with gunpowder.
+Mysorean rockets were an Indian military weapon, the first iron-cased rockets successfully deployed for military use. The Mysorean army, under Hyder Ali and his son Tipu Sultan, used the rockets effectively against the British East India Company during the 1780s and 1790s.
+
+The Indian war rockets were formidable weapons before such rockets were used in Europe. They had bam-boo rods, a rocket-body lashed to the rod, and iron points. They were directed at the target and fired by lighting the fuse, but the trajectory was rather erratic. The use of mines and counter-mines with explosive charges of gunpowder is mentioned for the times of Akbar and Jahāngir.
+
+== Civil engineering ==
+
+=== Canals ===
+Gunpowder was used for hydraulic engineering in China by 1541. Gunpowder blasting followed by dredging of the detritus was a technique which Chen Mu employed to improve the Grand Canal at the waterway where it crossed the Yellow River. In Europe, gunpowder was used in the construction of the Canal du Midi in Southern France. It was completed in 1681 and linked the Mediterranean sea with the Atlantic with 240 km of canal and 100 locks. Another noteworthy consumer of black powder was the Erie Canal in New York, which was 585 km long and took eight years to complete, starting in 1817.

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+title: "History of gunpowder"
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+---
+
+=== Mining ===
+Before gunpowder was applied to civil engineering, there were two ways to break up large rocks, by hard labor or by heating with large fires followed by rapid quenching. The earliest record for the use of gunpowder in mines comes from Hungary in 1627. It was introduced to Britain in 1638 by German miners, after which records are numerous. Until the invention of the safety fuse by William Bickford in 1831, the practice was extremely dangerous. Another reason for danger were the dense fumes given off and the risk of igniting flammable gas when used in coal mines.
+
+=== Tunnel construction ===
+Gunpowder was also extensively used in railway construction. At first railways followed the contours of the land, or crossed low ground by means of bridges and viaducts, but later railways made extensive use of cuttings and tunnels. One 2400-ft stretch of the 5.4 mi Box Tunnel on the Great Western Railway line between London and Bristol consumed a ton of gunpowder per week for over two years. The 12.9 km long Mont Cenis Tunnel was completed in 13 years starting in 1857 but, even with black powder, progress was only 25 cm a day until the invention of pneumatic drills sped up the work.
+
+== United States ==
+
+=== Revolutionary War ===
+During the American Revolutionary War, a number of caves were mined for saltpeter to make gunpowder when supplies from Europe were embargoed. Abigail Adams reputedly also made gunpowder at her family farm in Massachusetts.
+The New York Committee of Safety produced some essays on making gunpowder that were printed in 1776.
+
+=== Civil War ===
+During the American Civil War, British India was the main source for saltpeter for the manufacture of gunpowder for the Union armies. This supply was threatened by the British government during the Trent Affair, when Union naval forces stopped a British ship, the RMS Trent, and removed two Confederate diplomats. The British government responded in part by halting all exports of saltpeter to the United States, threatening their gunpowder manufacturing resources. Shortly thereafter, the situation was resolved and the Confederate diplomats were released.
+The Union Navy blockaded the southern Confederate States, which reduced the amount of gunpowder that could be imported from overseas. The Confederate Nitre and Mining Bureau was formed to produce gunpowder for the army and the navy from domestic resources. Nitre is the English spelling of "Niter". While carbon and sulfur were readily available throughout the south, potassium nitrate was often produced from the Calcium nitrate found in cave dirt, tobacco barn floors and barn stalls other places. A number of caves were mined, and the men and boys who worked in the caves were called "peter monkey", somewhat in imitation of the naval term "powder monkey" that was used for the boys who brought up charges of gunpowder on gunboats.
+On 13 November 1862, the Confederate government advertised in the Charleston Daily Courier for 20 or 30 "able bodied Negro men" to work in the new nitre beds at Ashley Ferry, S.C. The nitre beds were large rectangles of rotted manure and straw, moistened weekly with urine, "dung water", and liquid from privies, cesspools and drains, and turned over regularly.  The process was designed to yield saltpeter, an ingredient of gunpowder, which the Confederate army needed during the Civil War. The South was so desperate for saltpeter for gunpowder that one Alabama official reportedly placed a newspaper ad asking that the contents of chamber pots be saved for collection.  In the winter of 1863, scores of enslaved people were set to work extracting it from a huge cave in Barstow County, Ga., where they labored by torchlight in grim conditions, hauling out and processing the so-called "peter dirt",. In South Carolina, in April 1864, the Confederate government hired 31 enslaved people to work at the Ashley Ferry Nitre Works.
+
+== Decline ==
+The latter half of the 19th century saw the invention of nitroglycerin, nitrocellulose and smokeless powders which soon replaced traditional gunpowder in most civil and military applications.
+
+== See also ==
+
+== Notes ==

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+title: "History of gunpowder"
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+---
+
+==== Rockets ====
+The first fire arrows were arrows strapped with gunpowder incendiaries, but they eventually became gunpowder propelled projectiles (rockets). It's not certain when this happened. According to the History of Song, in 969 two Song generals, Yue Yifang and Feng Jisheng (馮繼升), invented a variant fire arrow which used gunpowder tubes as propellants. These fire arrows were shown to the emperor in 970 when the head of a weapons manufacturing bureau sent Feng Jisheng to demonstrate the gunpowder arrow design, for which he was heavily rewarded. However Joseph Needham argues that rockets could not have existed before the 12th century, since the gunpowder formulas listed in the Wujing Zongyao are not suitable as rocket propellant. According to Stephen G. Haw, there is only slight evidence that rockets existed prior to 1200 and it is more likely they were not produced or used for warfare until the latter half of the 13th century. Rockets are recorded to have been used by the Song navy in a military exercise dated to 1245. Internal-combustion rocket propulsion is mentioned in a reference to 1264, recording that the 'ground-rat,' a type of firework, had frightened the Empress-Mother Gongsheng at a feast held in her honor by her son the Emperor Lizong.
+In 975, the state of Wuyue sent to the Song dynasty a unit of soldiers skilled in the handling of fire arrows and in the same year, the Song used fire arrows to destroy the fleet of Southern Tang. In 994, the Liao dynasty attacked the Song and laid siege to Zitong with 100,000 troops. They were repelled with the aid of fire arrows. In 1000 a soldier by the name of Tang Fu (唐福) also demonstrated his own designs of gunpowder arrows, gunpowder pots (a proto-bomb which spews fire), and gunpowder caltrops, for which he was richly rewarded as well.
+The imperial court took great interest in the progress of gunpowder developments and actively encouraged as well as disseminated military technology. For example, in 1002 a local militia man named Shi Pu (石普) showed his own versions of fireballs and gunpowder arrows to imperial officials. They were so astounded that the emperor and court decreed that a team would be assembled to print the plans and instructions for the new designs to promulgate throughout the realm. The Song court's policy of rewarding military innovators was reported to have "brought about a great number of cases of people presenting technology and techniques" (器械法式) according to the official History of Song. Production of gunpowder and fire arrows heavily increased in the 11th century as the court centralized the production process, constructing large gunpowder production facilities, hiring artisans, carpenters, and tanners for the military production complex in the capital of Kaifeng. One surviving source circa 1023 lists all the artisans working in Kaifeng while another notes that in 1083 the imperial court sent 100,000 gunpowder arrows to one garrison and 250,000 to another.
+Evidence of gunpowder in the Liao dynasty and Western Xia is much sparser than in Song, but some evidence such as the Song decree of 1073 that all subjects were henceforth forbidden from trading sulfur and saltpeter across the Liao border, suggests that the Liao were aware of gunpowder developments to the south and coveted gunpowder ingredients of their own.
+
+=== Explosives ===
+
+Gunpowder bombs had been mentioned since the 11th century. In 1000 AD, the previously mentioned soldier, Tang Fu (唐福), demonstrated a design of a proto-bomb and other weaponry, and was rewarded for them. In the same year, Xu Dong wrote that trebuchets used bombs that were like "flying fire", suggesting that they were incendiaries. In the military text Wujing Zongyao of 1044, bombs such as the "ten-thousand fire flying sand magic bomb", "burning heaven fierce fire unstoppable bomb", and "thunderclap bomb" (pilipao) were mentioned. However detailed accounts of their use did not appear until the 12th century.
+The Jurchen people of Manchuria united under Wanyan Aguda and established the Jin dynasty in 1115. Allying with the Song, they rose rapidly to the forefront of East Asian powers and defeated the Liao dynasty in a shockingly short span of time, destroying the 150-year balance of power between the Song, Liao, and Western Xia. Remnants of the Liao fled to the west and became known as the Qara Khitai, or Western Liao to the Chinese. In the east, the fragile Song-Jin alliance dissolved once the Jin saw how badly the Song army had performed against Liao forces. Realizing the weakness of Song, the Jin grew tired of waiting and captured all five of the Liao capitals themselves. They proceeded to make war on Song, initiating the Jin-Song Wars.
+For the first time, two major powers would have access to equally formidable gunpowder weapons. Initially the Jin expected their campaign in the south to proceed smoothly given how poorly the Song had fared against the Liao. However they were met with stout resistance upon besieging Kaifeng in 1126 and faced the usual array of gunpowder arrows and fire bombs, but also a weapon called the "thunderclap bomb" (霹靂炮), which one witness wrote, "At night the thunderclap bombs were used, hitting the lines of the enemy well, and throwing them into great confusion. Many fled, screaming in fright." The thunderclap bomb was previously mentioned in the Wujing Zongyao, but this was the first recorded instance of its use. Its description in the text reads thus:

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+
+== References ==
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+Ágoston, Gábor (2005), Guns for the Sultan: Military Power and the Weapons Industry in the Ottoman Empire, Cambridge University Press, ISBN 978-0-521-60391-1
+Agrawal, Jai Prakash (2010), High Energy Materials: Propellants, Explosives and Pyrotechnics, Wiley-VCH
+Andrade, Tonio (2016), The Gunpowder Age: China, Military Innovation, and the Rise of the West in World History, Princeton University Press, ISBN 978-0-691-13597-7. Arnold, Thomas (2001), History of Warfare: The Renaissance at War
+koichIro, Thomas (2001), The Renaissance at War, Cassell & Co, ISBN 978-0-304-35270-8
+Benton, Captain James G. (1862). A Course of Instruction in Ordnance and Gunnery (2nd ed.). West Point, New York: Thomas Publications. ISBN 978-1-57747-079-3. {{cite book}}: ISBN / Date incompatibility (help)
+Breverton, Terry (2012), Breverton's Encyclopedia of Inventions
+Brown, G. I. (1998), The Big Bang: A History of Explosives, Sutton Publishing, ISBN 978-0-7509-1878-7. Buchanan, Brenda J. (2006), "Gunpowder, Explosives and the State: A Technological History", Technology and Culture, 49 (3), Aldershot: Ashgate: 785–86, doi:10.1353/tech.0.0051, ISBN 978-0-7546-5259-5, S2CID 111173101{{citation}}:  CS1 maint: work parameter with ISBN (link)
+Chase, Kenneth (2003), Firearms: A Global History to 1700, Cambridge University Press, ISBN 978-0-521-82274-9. Cocroft, Wayne (2000), Dangerous Energy: The archaeology of gunpowder and military explosives manufacture, Swindon: English Heritage, ISBN 978-1-85074-718-5
+Cook, Haruko Taya (2000), Japan at War: An Oral History, Phoenix Press
+Cowley, Robert (1993), Experience of War, Laurel. Cressy, David (2013), Saltpeter: The Mother of Gunpowder, Oxford University Press
+Crosby, Alfred W. (2002), Throwing Fire: Projectile Technology Through History, Cambridge University Press, ISBN 978-0-521-79158-8. Curtis, W. S. (2014), Long Range Shooting: A Historical Perspective, WeldenOwen. Earl, Brian (1978), Cornish Explosives, Cornwall: The Trevithick Society, ISBN 978-0-904040-13-5. Easton, S. C. (1952), Roger Bacon and His Search for a Universal Science: A Reconsideration of the Life and Work of Roger Bacon in the Light of His Own Stated Purposes, Basil Blackwell
+Ebrey, Patricia B. (1999), The Cambridge Illustrated History of China, Cambridge University Press, ISBN 978-0-521-43519-2
+Grant, R.G. (2011), Battle at Sea: 3,000 Years of Naval Warfare, DK Publishing. Hadden, R. Lee. 2005. "Confederate Boys and Peter Monkeys." Armchair General. January 2005. Adapted from a talk given to the Geological Society of America on 25 March 2004. Haines, Spencer (2017). "The 'Military Revolution' Arrives on the Central Eurasian Steppe: The Unique Case of the Zunghar (1676–1745)". Mongolica: An International Journal of Mongolian Studies. 51. International Association of Mongolists: 170–185. Harding, Richard (1999), Seapower and Naval Warfare, 1650–1830, UCL Press Limited
+Smee, Harry (2020), Gunpowder and Glory
+Haw, Stephen G. (2013), Cathayan Arrows and Meteors: The Origins of Chinese Rocketry
+al-Hassan, Ahmad Y. (2001), "Potassium Nitrate in Arabic and Latin Sources", History of Science and Technology in Islam, archived from the original on 2019-05-20, retrieved 2007-07-23. Hobson, John M. (2004), The Eastern Origins of Western Civilisation, Cambridge University Press. Johnson, Norman Gardner. "explosive". Encyclopædia Britannica. Chicago. Kelly, Jack (2004), Gunpowder: Alchemy, Bombards, & Pyrotechnics: The History of the Explosive that Changed the World, Basic Books, ISBN 978-0-465-03718-6. Khan, Iqtidar Alam (1996), "Coming of Gunpowder to the Islamic World and North India: Spotlight on the Role of the Mongols", Journal of Asian History, 30: 41–45. Khan, Iqtidar Alam (2004), Gunpowder and Firearms: Warfare in Medieval India, Oxford University Press
+Khan, Iqtidar Alam (2008), Historical Dictionary of Medieval India, The Scarecrow Press, Inc., ISBN 978-0-8108-5503-8
+Kinard, Jeff (2007), Artillery An Illustrated History of its Impact
+Konstam, Angus (2002), Renaissance War Galley 1470-1590, Osprey Publisher Ltd.. Liang, Jieming (2006), Chinese Siege Warfare: Mechanical Artillery & Siege Weapons of Antiquity, Singapore, Republic of Singapore: Leong Kit Meng, ISBN 978-981-05-5380-7
+Lidin, Olaf G. (2002), Tanegashima – The Arrival of Europe in Japan, Nordic Inst of Asian Studies, ISBN 978-8791114120
+Lorge, Peter (2005), Warfare in China to 1600, Routledge
+Lorge, Peter A. (2008), The Asian Military Revolution: from Gunpowder to the Bomb, Cambridge University Press, ISBN 978-0-521-60954-8
+Lu, Gwei-Djen (1988), "The Oldest Representation of a Bombard", Technology and Culture, 29 (3): 594–605, doi:10.2307/3105275, JSTOR 3105275, S2CID 112733319
+Lu, Yongxiang (2015), A History of Chinese Science and Technology 2
+May, Timothy (2012), The Mongol Conquests in World History, Reaktion Books
+McLahlan, Sean (2010), Medieval Handgonnes
+McNeill, William Hardy (1992), The Rise of the West: A History of the Human Community, University of Chicago Press. Morillo, Stephen (2008), War in World History: Society, Technology, and War from Ancient Times to the Present, Volume 1, To 1500, McGraw-Hill, ISBN 978-0-07-052584-9
+Needham, Joseph (1971), Science and Civilization in China, Volume 4 Part 3, Cambridge University Press
+Needham, Joseph (1976), Science and Civilization in China, Volume 5 Part 3, Cambridge University Press
+Needham, Joseph (1980), Science & Civilisation in China, Volume 5 Part 4, Cambridge University Press, ISBN 978-0-521-08573-1
+Needham, Joseph (1986), Science & Civilisation in China, Volume 5 Part 7: The Gunpowder Epic, Cambridge University Press, ISBN 978-0-521-30358-3
+Nicolle, David (1990), The Mongol Warlords: Genghis Khan, Kublai Khan, Hulegu, Tamerlane
+Nicolle, David (1983), Armies of the Ottoman Turks 1300-1774
+Nolan, Cathal J. (2006), The Age of Wars of Religion, 1000–1650: an Encyclopedia of Global Warfare and Civilization, Vol 1, A-K, vol. 1, Westport & London: Greenwood Press, ISBN 978-0-313-33733-8
+Norris, John (2003), Early Gunpowder Artillery: 1300–1600, Marlborough: The Crowood Press. Padmanabhan, Thanu (2019), The Dawn of Science: Glimpses from History for the Curious Mind, Bibcode:2019dsgh.book.....P
+Partington, J. R. (1960), A History of Greek Fire and Gunpowder, Cambridge, UK: W. Heffer & Sons. Partington, J. R. (1999), A History of Greek Fire and Gunpowder, Baltimore: Johns Hopkins University Press, ISBN 978-0-8018-5954-0
+Patrick, John Merton (1961), Artillery and warfare during the thirteenth and fourteenth centuries, Utah State University Press. Pauly, Roger (2004), Firearms: The Life Story of a Technology, Greenwood Publishing Group. Perrin, Noel (1979), Giving up the Gun, Japan's reversion to the Sword, 1543–1879, Boston: David R. Godine, ISBN 978-0-87923-773-8
+Petzal, David E. (2014), The Total Gun Manual (Canadian edition), WeldonOwen. Phillips, Henry Prataps (2016), The History and Chronology of Gunpowder and Gunpowder Weapons (c.1000 to 1850), Notion Press
+Pregadio, Fabrizio (2011), The Seal of the Unity of the Three
+Purton, Peter (2009), A History of the Early Medieval Siege c. 450–1200, The Boydell Press
+Purton, Peter (2010), A History of the Late Medieval Siege, 1200–1500, Boydell Press, ISBN 978-1-84383-449-6
+Robins, Benjamin (1742), New Principles of Gunnery
+Romane, Julian (2020), The First & Second Italian Wars 1494-1504
+Rose, Susan (2002), Medieval Naval Warfare 1000–1500, Routledge
+Roy, Kaushik (2015), Warfare in Pre-British India, Routledge
+Sasaki, Randall J. (2015). The Origins of the Lost Fleet of the Mongol Empire. Schmidtchen, Volker (1977a), "Riesengeschütze des 15. Jahrhunderts. Technische Höchstleistungen ihrer Zeit", Technikgeschichte 44 (2): 153–173 (153–157)
+Schmidtchen, Volker (1977b), "Riesengeschütze des 15. Jahrhunderts. Technische Höchstleistungen ihrer Zeit", Technikgeschichte 44 (3): 213–237 (226–228)
+Tran, Nhung Tuyet (2006), Viêt Nam Borderless Histories, University of Wisconsin Press. Turnbull, Stephen (2003), Fighting Ships Far East (2: Japan and Korea AD 612–1639, Osprey Publishing, ISBN 978-1-84176-478-8
+Urbanski, Tadeusz (1967), Chemistry and Technology of Explosives, vol. III, New York: Pergamon Press. Villalon, L. J. Andrew (2008), The Hundred Years War (part II): Different Vistas, Brill Academic Pub, ISBN 978-90-04-16821-3
+Wagner, John A.

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+---
+title: "History of gunpowder"
+chunk: 22/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+(2006), The Encyclopedia of the Hundred Years War, Westport & London: Greenwood Press, ISBN 978-0-313-32736-0
+Watson, Peter (2006), Ideas: A History of Thought and Invention, from Fire to Freud, Harper Perennial (2006), ISBN 978-0-06-093564-1
+Wilkinson, Philip (9 September 1997), Castles, Dorling Kindersley, ISBN 978-0-7894-2047-3
+Wilkinson-Latham, Robert (1975), Napoleon's Artillery, France: Osprey Publishing, ISBN 978-0-85045-247-1
+Willbanks, James H. (2004), Machine guns: an illustrated history of their impact, ABC-CLIO, Inc. Williams, Anthony G. (2000), Rapid Fire, Shrewsbury: Airlife Publishing Ltd., ISBN 978-1-84037-435-3
+Kouichiro, Hamada (2012), 日本人はこうして戦争をしてきた
+Tatsusaburo, Hayashiya (2005), 日本の歴史12 - 天下一統
+
+== External links ==
+"A Guide to Geometry, Surveying, the Launching of Missiles, and the Planting of Mines" from 1791, in Arabic, discusses the storing of gunpowder and related subjects in the 18th-century Muslim world.

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+---
+title: "History of gunpowder"
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+
+The thunderclap bomb contains a length of two or three internodes of dry bamboo with a diameter of 1.5 in. There must be no cracks, and the septa are to be retained to avoid any leakage. Thirty pieces of thin broken porcelain the size of iron coins are mixed with 3 or 4 lb of gunpowder, and packed around the bamboo tube. The tube is wrapped within the ball, but with about an inch or so protruding at each end. A (gun)powder mixture is then applied all over the outer surface of the ball.
+Jin troops withdrew with a ransom of Song silk and treasure but returned several months later with their own gunpowder bombs manufactured by captured Song artisans. According to historian Wang Zhaochun, the account of this battle provided the "earliest truly detailed descriptions of the use of gunpowder weapons in warfare." Records show that the Jin used gunpowder arrows and trebuchets to hurl gunpowder bombs while the Song responded with gunpowder arrows, fire bombs, thunderclap bombs, and a new addition called the "molten metal bomb" (金汁炮). As the Jin account describes, when they attacked the city's Xuanhua Gate, their "fire bombs fell like rain, and their arrows were so numerous as to be uncountable." The Jin captured Kaifeng despite the appearance of the molten metal bomb and secured another 20,000 fire arrows for their arsenal.
+The molten metal bomb appeared again in 1129 when Song general Li Yanxian (李彥仙) clashed with Jin forces while defending a strategic pass. The Jin assault lasted day and night without respite, using siege carts, fire carts, and sky bridges, but each assault was met with Song soldiers who "resisted at each occasion, and also used molten metal bombs. Wherever the gunpowder touched, everything would disintegrate without a trace." The molten metal bomb was likely an explosive that contained molten metal and gunpowder.
+
+=== Fire lance ===
+
+The Song relocated their capital to Hangzhou and the Jin followed. The fighting that ensued would see the first proto-gun, the fire lance, in action – with earliest confirmed employment by Song dynasty forces against the Jin in 1132 during the siege of De'an (modern Anlu, Hubei), Most Chinese scholars reject the appearance of the fire lance prior to the Jin-Song wars, but its first appearance in art with a silk banner painting from Dunhuang dates to the Five Dynasties and Ten Kingdoms period in the mid-10th century.
+The siege of De'an marks an important transition and landmark in the history of gunpowder weapons as the fire medicine of the fire lances were described using a new word: "fire bomb medicine" (火炮藥), rather than simply "fire medicine." This could imply the use of a new more potent formula, or simply an acknowledgement of the specialized military application of gunpowder. Peter Lorge suggests that this "bomb powder" may have been corned, making it distinct from normal gunpowder. Evidence of gunpowder firecrackers also points to their appearance at roughly around the same time fire medicine was making its transition in the literary imagination.
+Fire lances continued to be used as anti-personnel weapons into the Ming dynasty, and were even attached to battle carts on one situation in 1163. Song commander Wei Sheng constructed several hundred of these carts known as "at-your-desire-war-carts" (如意戰車), which contained fire lances protruding from protective covering on the sides. They were used to defend mobile trebuchets that hurled fire bombs. They were used as cavalry weapons by the 13th century.
+
+=== Naval bombs ===
+Gunpowder technology also spread to naval warfare and in 1129 Song decreed that all warships were to be fitted with trebuchets for hurling gunpowder bombs. Older gunpowder weapons such as fire arrows were also used. In 1159 a Song fleet of 120 ships caught a Jin fleet at anchor near Shijiu Island (石臼島) off the shore of Shandong peninsula. The Song commander "ordered that gunpowder arrows be shot from all sides, and wherever they struck, flames and smoke rose up in swirls, setting fire to several hundred vessels." Song forces took another victory in 1161 when Song paddle boats ambushed a Jin transport fleet, launched thunderclap bombs, and drowned the Jin force in the Yangtze.

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+---
+title: "History of gunpowder"
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+
+The men inside them paddled fast on the treadmills, and the ships glided forwards as though they were flying, yet no one was visible on board. The enemy thought that they were made of paper. Then all of a sudden
+a thunderclap bomb was let off: It was made with paper (carton) and filled with lime and sulphur. (Launched from trebuchets) these thunderclap bombs came dropping down from the air, and upon meeting the water exploded with a noise like thunder, the sulphur bursting into flames. The carton case rebounded and broke, scattering the lime to form a smoky fog which blinded the eyes of men and horses so that they could see nothing. Our ships then went forward to attack theirs, and their men and horses were all drowned, so that they were utterly defeated.
+According to a minor military official by the name of Zhao Wannian (趙萬年), thunderclap bombs were used again to great effect by the Song during the Jin siege of Xiangyang in 1206–1207. Both sides had gunpowder weapons, but the Jin troops only used gunpowder arrows for destroying the city's moored vessels. The Song used fire arrows, fire bombs, and thunderclap bombs. Fire arrows and bombs were used to destroy Jin trebuchets. The thunderclap bombs were used on Jin soldiers themselves, causing foot soldiers and horsemen to panic and retreat. "We beat our drums and yelled from atop the city wall, and simultaneously fired our thunderclap missiles out from the city walls. The enemy cavalry was terrified and ran away." The Jin were forced to retreat and make camp by the riverside. In a rare occurrence, the Song made a successful offensive on Jin forces and conducted a night assault using boats. They were loaded with gunpowder arrows, thunderclap bombs, a thousand crossbowmen, five hundred infantry, and a hundred drummers. Jin troops were surprised in their encampment while asleep by loud drumming, followed by an onslaught of crossbow bolts, and then thunderclap bombs, which caused a panic of such magnitude that they were unable to even saddle themselves and trampled over each other trying to get away. Two to three thousand Jin troops were slaughtered along with eight to nine hundred horses.
+
+=== Hard-shell explosives ===
+Traditionally the inspiration for the development of the iron bomb is ascribed to the tale of a fox hunter named Iron Li. According to the story, around the year 1189 Iron Li developed a new method for hunting foxes which used a ceramic explosive to scare foxes into his nets. The explosive consisted of a ceramic bottle with a mouth, stuffed with gunpowder, and attached with a fuse. Explosive and net were placed at strategic points of places such as watering holes frequented by foxes, and when they got near enough, Iron Li would light the fuse, causing the ceramic bottle to explode and scaring the frightened foxes right into his nets. Although the veracity of this story is uncertain, the tradition holds that this ceramic bomb inspired the Jin to create an iron version.
+The iron bomb made its first appearance in 1221 at the siege of Qizhou (in modern Hubei), and this time it would be the Jin who possessed the technological advantage. The Song commander Zhao Yurong (趙與褣) survived and was able to relay his account for posterity.
+Qizhou was a major fortress city situated near the Yangtze and a 25 thousand strong Jin army advanced on it in 1221. News of the approaching army reached Zhao Yurong in Qizhou, and despite being outnumbered nearly eight to one, he decided to hold the city. Qizhou's arsenal consisted of some three thousand thunderclap bombs, twenty thousand "great leather bombs" (皮大炮), and thousands of gunpowder arrows and gunpowder crossbow bolts. While the formula for gunpowder had become potent enough to consider the Song bombs to be true explosives, they were unable to match the explosive power of the Jin iron bombs. Yurong describes the uneven exchange thus, "The barbaric enemy attacked the Northwest Tower with an unceasing flow of catapult projectiles from thirteen catapults. Each catapult shot was followed by an iron fire bomb [catapult shot], whose sound was like thunder. That day, the city soldiers in facing the catapult shots showed great courage as they maneuvered [our own] catapults, hindered by injuries from the iron fire bombs. Their heads, their eyes, their cheeks were exploded to bits, and only one half [of the face] was left." Jin artillerists were able to successfully target the command center itself: "The enemy fired off catapult stones ... nonstop day and night, and the magistrate's headquarters [帳] at the eastern gate, as well as my own quarters ..., were hit by the most iron fire bombs, to the point that they struck even on top of [my] sleeping quarters and [I] nearly perished! Some said there was a traitor. If not, how would they have known the way to strike at both of these places?"
+Zhao was able to examine the new iron bombs himself and described thus, "In shape they are like gourds, but with a small mouth. They are made with pig iron, about two inches thick, and they cause the city's walls to shake." Houses were blown apart, towers battered, and defenders blasted from their placements. Within four weeks all four gates were under heavy bombardment. Finally the Jin made a frontal assault on the walls and scaled them, after which followed a merciless hunt for soldiers, officers, and officials of every level. Zhao managed an escape by clambering over the battlement and making a hasty retreat across the river, but his family remained in the city. Upon returning at a later date to search the ruins, he found that the "bones and skeletons were so mixed up that there was no way to tell who was who."
+
+=== Hand cannon ===

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+title: "History of gunpowder"
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+
+The early fire lance, considered to be the ancestor of firearms, is not considered a true gun because it did not include projectiles, whereas a gun by definition uses "the explosive force of the gunpowder to propel a projectile from a tube: cannons, muskets, and pistols are typical examples.". Even later on when shrapnel such as ceramics and bits of iron were added to the fire lance, these didn't occlude the barrel, and were only swept along with the discharge rather than making use of windage, and so are referred to as "co-viatives."
+In 1259 a type of "fire-emitting lance" (tuhuoqiang 突火槍) made an appearance and according to the History of Song: "It is made from a large bamboo tube, and inside is stuffed a pellet wad (子窠). Once the fire goes off it completely spews the rear pellet wad forth, and the sound is like a bomb that can be heard for five hundred or more paces." The pellet wad mentioned is possibly the first true bullet in recorded history depending on how bullet is defined, as it did occlude the barrel, unlike previous co-viatives used in the fire lance. Fire lances transformed from the "bamboo- (or wood- or paper-) barreled firearm to the metal-barreled firearm" to better withstand the explosive pressure of gunpowder. From there it branched off into several different gunpowder weapons known as "eruptors" in the late 12th and early 13th centuries, with different functions such as the "filling-the-sky erupting tube" which spewed out poisonous gas and porcelain shards, the "orifice-penetrating flying sand magic mist tube" (鑽穴飛砂神霧筒) which spewed forth sand and poisonous chemicals into orifices, and the more conventional "phalanx-charging fire gourd" which shot out lead pellets.
+The earliest artistic depiction of what might be a hand cannon – a rock sculpture found among the Dazu Rock Carvings – is dated to 1128, much earlier than any recorded or precisely dated archaeological samples, so it is possible that the concept of a cannon-like firearm has existed since the 12th century. This has been challenged by others such as Liu Xu, Cheng Dong, and Benjamin Avichai Katz Sinvany. According to Liu, the weight of the cannon would have been too much for one person to hold, especially with just one arm, and points out that fire lances were being used a decade later at De'an. Cheng Dong believes that the figure depicted is actually a wind spirit letting air out of a bag rather than a cannon emitting a blast. Stephen Haw also considered the possibility that the item in question was a bag of air but concludes that it is a cannon because it was grouped with other weapon wielding sculptures. Sinvany believes in the wind bag interpretation and that the cannonball indentation was added later on.
+Archaeological samples of the gun, specifically the hand cannon (huochong), have been dated starting from the 13th century. The oldest extant gun whose dating is unequivocal is the Xanadu Gun because it contains an inscription describing its date of manufacture corresponding to 1298. It is so called because it was discovered in the ruins of Xanadu, the Mongol summer palace in Inner Mongolia. The Xanadu Gun is 34.7 cm in length and weighs 6.2 kg. The design of the gun includes axial holes in its rear which some speculate could have been used in a mounting mechanism. Like most early guns it is small, weighing just over six kilograms and thirty-five centimeters in length. Although the Xanadu Gun is the most precisely dated gun from the 13th century, other extant samples with approximate dating likely predate it. The Heilongjiang hand cannon is dated a decade earlier to 1288, but the dating method is based on contextual evidence; the gun bears no inscription or era date. According to the History of Yuan, in 1287, a group of soldiers equipped with hand cannons led by the Jurchen commander Li Ting (李庭) attacked the rebel prince Nayan's camp. The History reports that the hand cannons not only "caused great damage," but also caused "such confusion that the enemy soldiers attacked and killed each other." The hand cannons were used again in the beginning of 1288. Li Ting's "gun-soldiers" or chongzu (銃卒) were able to carry the hand cannons "on their backs". The passage on the 1288 battle is also the first to coin the name chong (銃) for metal-barrel firearms. Chong was used instead of the earlier and more ambiguous term huo tong (fire tube; 火筒), which may refer to the tubes of fire lances, proto-cannons, or signal flares.
+Another specimen, the Wuwei Bronze Cannon, was discovered in 1980 and may possibly be the oldest as well as largest cannon of the 13th century: a 100 centimeter 108 kilogram bronze cannon discovered in a cellar in Wuwei, Gansu containing no inscription, but has been dated by historians to the late Western Xia period between 1214 and 1227. The gun contained an iron ball about nine centimeters in diameter, which is smaller than the muzzle diameter at twelve centimeters, and 0.1 kilograms of gunpowder in it when discovered, meaning that the projectile might have been another co-viative. Ben Sinvany and Dang Shoushan believe that the ball used to be much larger prior to its highly corroded state at the time of discovery. While large in size, the weapon is noticeably more primitive than later Yuan dynasty guns, and is unevenly cast. A similar weapon was discovered not far from the discovery site in 1997, but much smaller in size at only 1.5 kg. Chen Bingying disputes this however, and argues there were no guns before 1259, while Dang Shoushan believes the Western Xia guns point to the appearance of guns by 1220, and Stephen Haw goes even further by stating that guns were developed as early as 1200. Sinologist Joseph Needham and renaissance siege expert Thomas Arnold provide a more conservative estimate of around 1280 for the appearance of the "true" cannon.
+Whether or not any of these are correct, it seems likely that the gun was born sometime during the 13th century.

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+---
+title: "History of gunpowder"
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+instance: "kb-cron"
+---
+
+== Use by the Mongols ==
+
+The Mongols and their rise in world history as well as conflicts with both the Jin and Song played a key role in the evolution of gunpowder technology. Mongol aptitude in incorporating foreign experts extended to the Chinese, who provided artisans that followed Mongol armies willingly and unwillingly far into the west and even east, to Japan. Unfortunately textual evidence for this is scant as the Mongols left few documents. This lack of primary source documents has caused some historians and scholars such as Kate Raphael to doubt the Mongol's role in disseminating gunpowder throughout Eurasia. On the opposite side stand historians such as Tonio Andrade and Stephen Haw, who believe that the Mongol Empire not only used gunpowder weapons but deserves the moniker "the first gunpowder empire."
+
+=== Conquest of the Jin dynasty ===
+
+The first concerted Mongol invasion of Jin occurred in 1211 and total conquest was not accomplished until 1234. In 1232 the Mongols besieged the Jin capital of Kaifeng and deployed gunpowder weapons along with other more conventional siege techniques such as building stockades, watchtowers, trenches, guardhouses, and forcing Chinese captives to haul supplies and fill moats. Jin scholar Liu Qi (劉祈) recounts in his memoir, "the attack against the city walls grew increasingly intense, and bombs rained down as [the enemy] advanced." The Jin defenders also deployed gunpowder bombs as well as fire arrows (huo jian 火箭) launched using a type of early solid-propellant rocket. Of the bombs, Liu Qi writes, "From within the walls the defenders responded with a gunpowder bomb called the heaven-shaking-thunder bomb (震天雷). Whenever the [Mongol] troops encountered one, several men at a time would be turned into ashes."
+A more fact based and clear description of the bomb exists in the History of Jin: "The heaven-shaking-thunder bomb is an iron vessel filled with gunpowder. When lighted with fire and shot off, it goes off like a crash of thunder that can be heard for a hundred li [thirty miles], burning an expanse of land more than half a mu [所爇圍半畝之上, a mu is a sixth of an acre], and the fire can even penetrate iron armor." A Ming official named He Mengchuan would encounter an old cache of these bombs three centuries later in the Xi'an area: "When I went on official business to Shaanxi Province, I saw on top of Xi'an's city walls an old stockpile of iron bombs. They were called 'heaven-shaking-thunder' bombs, and they were like an enclosed rice bowl with a hole at the top, just big enough to put your finger in. The troops said they hadn't been used for a very long time." Furthermore, he wrote, "When the powder goes off, the bomb rips open, and the iron pieces fly in all directions. That is how it is able to kill people and horses from far away."
+Heaven-shaking-thunder bombs, also known as thunder crash bombs, were used prior to the siege in 1231 when a Jin general made use of them in destroying a Mongol warship. The Jin general named Wanyan Eke had lost the defense of Hezhong to the Mongols and fled on ships with 3,000 of his men. The Mongols pursued them with their ships until the Jin broke through by using thunder crash bombs that caused flashes and flames. However, during the siege the Mongols responded by protecting themselves with elaborate screens of thick cowhide. This was effective enough for workers to get right up to the walls to undermine their foundations and excavate protective niches. Jin defenders countered by tying iron cords and attaching them to heaven-shaking-thunder bombs, which were lowered down the walls until they reached the place where the miners worked. The protective leather screens were unable to withstand the explosion, and were penetrated, killing the excavators.
+Another weapon the Jin employed was an improved version of the fire lance called the flying fire lance. The History of Jin provides a detailed description: "To make the lance, use chi-huang paper, sixteen layers of it for the tube, and make it a bit longer than two feet. Stuff it with willow charcoal, iron fragments, magnet ends, sulfur, white arsenic [probably an error that should mean saltpeter], and other ingredients, and put a fuse to the end. Each troop has hanging on him a little iron pot to keep fire [probably hot coals], and when it's time to do battle, the flames shoot out the front of the lance more than ten feet, and when the gunpowder is depleted, the tube isn't destroyed." While Mongol soldiers typically held a view of disdain toward most Jin weapons, apparently they greatly feared the flying fire lance and heaven-shaking-thunder bomb. Kaifeng managed to hold out for a year before the Jin emperor fled and the city capitulated. In some cases Jin troops still fought with some success, scoring isolated victories such as when a Jin commander led 450 fire lancers against a Mongol encampment, which was "completely routed, and three thousand five hundred were drowned." Even after the Jin emperor committed suicide in 1234, one loyalist gathered all the metal he could find in the city he was defending, even gold and silver, and made explosives to lob against the Mongols, but the momentum of the Mongol Empire could not be stopped. By 1234, both the Western Xia and Jin dynasty had been conquered.
+
+=== Conquest of the Song dynasty ===

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+title: "History of gunpowder"
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+---
+
+The Mongol war machine moved south and in 1237 attacked the Song city of Anfeng (modern Shouxian, Anhui) "using gunpowder bombs [huo pao] to burn the [defensive] towers." These bombs were apparently quite large. "Several hundred men hurled one bomb, and if it hit the tower it would immediately smash it to pieces." The Song defenders under commander Du Gao (杜杲) rebuilt the towers and retaliated with their own bombs, which they called the "Elipao," after a famous local pear, probably in reference to the shape of the weapon. Perhaps as another point of military interest, the account of this battle also mentions that the Anfeng defenders were equipped with a type of small arrow to shoot through eye slits of Mongol armor, as normal arrows were too thick to penetrate.
+By the mid 13th century, gunpowder weapons had become central to the Song war effort. In 1257 the Song official Li Zengbo was dispatched to inspect frontier city arsenals. Li considered an ideal city arsenal to include several hundred thousand iron bombshells, and also its own production facility to produce at least a couple thousand a month. The results of his tour of the border were severely disappointing and in one arsenal he found "no more than 85 iron bomb-shells, large and small, 95 fire-arrows, and 105 fire-lances. This is not sufficient for a mere hundred men, let alone a thousand, to use against an attack by the ... barbarians. The government supposedly wants to make preparations for the defense of its fortified cities, and to furnish them with military supplies against the enemy (yet this is all they give us). What chilling indifference!" Fortunately for the Song, Möngke Khan died in 1259 and the war would not continue until 1269 under the leadership of Kublai Khan, but when it did the Mongols came in full force.
+Blocking the Mongols' passage south of the Yangtze were the twin fortress cities of Xiangyang and Fancheng. What resulted was one of the longest sieges the world had ever known, lasting from 1268 to 1273. Song relief forces used fire lances, fire bombs, and crossobws to break a blockade on Xiangyang. In 1273 the Mongols enlisted the expertise of two Muslim engineers, one from Persia and one from Syria, who helped in the construction of counterweight trebuchets. These new siege weapons had the capability of throwing larger missiles further than the previous traction trebuchets. One account records, "when the machinery went off the noise shook heaven and earth; every thing that [the missile] hit was broken and destroyed."
+The next major battle to feature gunpowder weapons was during a campaign led by the Mongol general Bayan, who commanded an army of around two hundred thousand, consisting of mostly Chinese soldiers. It was probably the largest army the Mongols had ever used. Such an army was still unable to successfully storm Song city walls, as seen in the 1274 Siege of Shayang. Thus Bayan waited for the wind to change to a northerly course before ordering his artillerists to begin bombarding the city with molten metal bombs, which caused such a fire that "the buildings were burned up and the smoke and flames rose up to heaven." Shayang was captured and its inhabitants massacred.
+Gunpowder bombs were used again in the 1275 Siege of Changzhou in the latter stages of the Mongol-Song Wars. Upon arriving at the city, Bayan gave the inhabitants an ultimatum: "if you ... resist us ... we shall drain your carcasses of blood and use them for pillows." This didn't work and the city resisted anyway, so the Mongol army bombarded them with fire bombs before storming the walls, after which followed an immense slaughter claiming the lives of a quarter million. The war lasted for only another four years during which some remnants of the Song held up last desperate defenses. In 1277, 250 defenders under Lou Qianxia conducted a suicide bombing and set off a huge iron bomb when it became clear defeat was imminent. Of this, the History of Song writes, "the noise was like a tremendous thunderclap, shaking the walls and ground, and the smoke filled up the heavens outside. Many of the troops [outside] were startled to death. When the fire was extinguished they went in to see. There were just ashes, not a trace left." So came an end to the Mongol-Song Wars, which saw the deployment of all the gunpowder weapons available to both sides at the time, which for the most part meant gunpowder arrows, bombs, and lances, but in retrospect, another development would overshadow them all, the birth of the gun.
+In 1280, a large store of gunpowder at Weiyang in Yangzhou accidentally caught fire, producing such a massive explosion that a team of inspectors at the site a week later deduced that some 100 guards had been killed instantly, with wooden beams and pillars blown sky high and landing at a distance of over 10 li (~2 mi. or ~3 km) away from the explosion, creating a crater more than ten feet deep.
+By the time of Jiao Yu and his Huolongjing (a book that describes military applications of gunpowder in great detail) in the mid 14th century, the explosive potential of gunpowder was perfected, as the level of nitrate in gunpowder formulas had risen from a range of 12% to 91%, with at least 6 different formulas in use that are considered to have maximum explosive potential for gunpowder. By that time, the Chinese had discovered how to create explosive round shot by packing their hollow shells with this nitrate-enhanced gunpowder.
+
+=== Invasions of Europe, Japan, and South East Asia ===

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+---
+title: "History of gunpowder"
+chunk: 9/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
+instance: "kb-cron"
+---
+
+Gunpowder may have been used during the Mongol invasions of Europe. "Fire catapults", "pao", and "naphtha-shooters" are mentioned in some sources. However, according to Timothy May, "there is no concrete evidence that the Mongols used gunpowder weapons on a regular basis outside of China."
+Shortly after the Mongol invasions of Japan (1274–1281), the Japanese produced a scroll painting depicting a bomb. Called tetsuhau in Japanese, the bomb is speculated to have been the Chinese thunder crash bomb. Archaeological findings by the Kyushu Okinawa Society for Underwater Archaeology confirmed the existence of bombs in the Yuan invasion's arsenal. Multiple bomb shells were discovered in an underwater shipwreck off the shore of Japan and X-rays of the excavated shells show that they contained gunpowder and were also packed with scrap iron. Japanese descriptions of the invasions also talk of iron and bamboo pao causing "light and fire" and emitting 2–3,000 iron bullets. The Nihon Kokujokushi, written around 1300, mentions huo tong (fire tubes) at the Battle of Tsushima in 1274 and the second coastal assault led by Holdon in 1281. The Hachiman Gudoukun of 1360 mentions iron pao "which caused a flash of light and a loud noise when fired." The Taiheki of 1370 mentions "iron pao shaped like a bell."
+
+The commanding general kept his position on high ground, and directed the various detachments as need be with signals from hand-drums. But whenever the (Mongol) soldiers took to flight, they sent iron bomb-shells (tetsuho) flying against us, which made our side dizzy and confused. Our soldiers were frightened out of their wits by the thundering explosions; their eyes were blinded, their ears deafened, so that they could hardly distinguish east from west. According to our manner of fighting, we must first call out by name someone from the enemy ranks, and then attack in single combat. But they (the Mongols) took no notice at all of such conventions; they rushed forward all together in a mass, grappling with any individuals they could catch and killing them.
+To punish King Kertanagara, Kubilai Khan consolidated his forces in 1293 to invade Java with a combined army of Yuan and Tartar troops. The expeditionary force was equipped with a diverse arsenal utilizing gunpowder, ranging from small rockets to early cannons. According to Jawaharlal Nehru in his work Glimpses of World History, there is a strong assertion that the Mongol invasion of Java significantly influenced the development and advancement of weapon technology within the Majapahit Empire.
+
+== Historiography of gunpowder and gun transmission ==

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+---
+title: "History of gunpowder"
+chunk: 10/22
+source: "https://en.wikipedia.org/wiki/History_of_gunpowder"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:19.654773+00:00"
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+---
+
+According to historian Tonio Andrade, "Scholars today overwhelmingly concur that the gun was invented in China," however multiple independent gunpowder and gun invention theories continue to exist today, advocating for European, Islamic, or Indian origins. Opponents of Chinese invention and transmission criticize the vagueness of Chinese records on specific gunpowder usage in weaponry, the possible lack of gunpowder in incendiary weapons as described by Chinese documents, the weakness of Chinese firearms, the lack of evidence of guns between Europe and China before 1326, and emphasize the appearance of earlier or superior gunpowder weapons. For example, Stephen Morillo, Jeremy Black, and Paul Lococo's War in World History argues that "the sources are not entirely clear about Chinese use of gunpowder in guns. There are references to bamboo and iron cannons, or perhaps proto-cannons, but these seem to have been small, unreliable, handheld weapons in this period. The Chinese do seem to have invented guns independently of the Europeans, at least in principle; but, in terms of effective cannon, the edge goes to Europe." Independent invention theories include examples such as the attribution of gunpowder to Berthold Schwarz (Black Berthold), the usage of cannons by Mamluks at the Battle of Ain Jalut in 1260, and descriptions of gunpowder and firearms to various Sanskrit texts. The problem with all theories of non-Chinese invention boils down to lack of evidence and dating. It's not certain who exactly Berthold Schwarz was since there are no contemporary records of him. According to J.R. Partington, Black Berthold is a purely legendary figure invented for the purpose of providing a German origin for gunpowder and cannon. The source for Mamluk usage of cannons in the Battle of Ain Jalut is a text dated to the late 14th century. The dating of the cited Sanskrit texts is often dubious at best, with one example, Sukraniti, containing descriptions of a musket and a cart-drawn gun.
+Proponents of Chinese invention and transmission point out the lack of any significant evidence of evolution or experimentation with gunpowder or gunpowder weapons leading up to the gun outside of China. Gunpowder appeared in Europe primed for military usage as an explosive and propellant, bypassing a process which took centuries of Chinese experimentation with gunpowder weaponry to reach, making a nearly instantaneous and seamless transition into firearm warfare, as its name suggests. Furthermore, early European gunpowder recipes shared identical defects with Chinese recipes such as the inclusion of the poisons sal ammoniac and arsenic, which provide no benefit to gunpowder. Bert S. Hall explains this phenomenon in his Weapons and Warfare in Renaissance Europe: Gunpowder, Technology, and Tactics by drawing upon the gunpowder transmission theory, explaining that "gunpowder came [to Europe], not as an ancient mystery, but as a well-developed modern technology, in a manner very much like twentieth-century 'technology-transfer' projects." In a similar vein, Peter Lorge supposes that the Europeans experienced gunpowder "free from preconceived notions of what could be done," in contrast to China, "where a wide range of formulas and a broad variety of weapons demonstrated the full range of possibilities and limitations of the technologies involved." There is also the vestige of Chinese influence on Muslim terminology of key gunpowder related items such as saltpeter, which has been described as either Chinese snow or salt, fireworks which were called Chinese flowers, and rockets which were called Chinese arrows. Moreover, Europeans in particular experienced great difficulty in obtaining saltpeter, a primary ingredient of gunpowder which was relatively scarce in Europe compared to China, and had to be obtained from "distant lands or extracted at high cost from soil rich in dung and urine." Thomas Arnold believes that the similarities between early European cannons and contemporary Chinese models suggests a direct transmission of cannon making knowledge from China rather than a home grown development.
+
+== Spread throughout Eurasia and Africa ==
+
+=== Middle East ===

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+---
+title: "History of lead"
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+category: "reference"
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+date_saved: "2026-05-05T16:15:22.223075+00:00"
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+---
+
+Lead (chemical symbol: Pb, atomic number: 82) is one of the earliest metals worked by humans. It is known to have been smelted as early as the 7th millennium BC and spread widely due to its frequent association with silver ores. Ancient civilizations across the Near East, Mediterranean, Asia, Africa, and the Americas employed lead in construction, tools, currency, cosmetics, warfare, and writing, with production reaching a peak during the Roman Empire. After the fall of the Western Roman Empire, lead mining and use expanded in Asia and later revived in Europe during the Middle Ages and Renaissance, when it was also central to alchemy, printing, architecture, and armaments. The Industrial Revolution marked a new period of large-scale production and widespread exposure, leading to increased recognition of lead’s toxicity and the introduction of public health regulations. In the 20th century, lead was progressively restricted in paints, plumbing, and fuels due to its health impacts, while remaining important in industrial applications such as lead–acid batteries, with global production patterns shifting toward Eastern Europe and Asia.
+
+== Prehistory and early history ==
+Metallic lead beads dating back to 7000–6500 BC have been found in Asia Minor and may represent the first example of metal smelting. At that time, lead had few (if any) applications due to its softness and dull appearance. The major reason for the spread of lead production was its association with silver, which may be obtained by burning galena (a common lead mineral). The Ancient Egyptians were the first to use lead minerals in cosmetics, an application that spread to Ancient Greece and beyond; the Egyptians had used lead for sinkers in fishing nets, glazes, glasses, enamels, ornaments. Various civilizations of the Fertile Crescent used lead as a writing material, as coins, and as a construction material. Lead was used by the ancient Chinese as a stimulant, as currency, as contraceptive, and in chopsticks. The Indus Valley civilization and the Mesoamericans used it for making amulets; and the eastern and southern Africans used lead in wire drawing.
+
+== Classical era ==
+Because silver was extensively used as a decorative material and an exchange medium, lead deposits came to be worked in Asia Minor from 3000 BC; later, lead deposits were developed in the Aegean and Laurion. These three regions collectively dominated production of mined lead until c. 1200 BC. Beginning c. 2000 BC, the Phoenicians worked deposits in the Iberian peninsula; by 1600 BC, lead mining existed in Cyprus, Greece, and Sardinia.
+Rome's territorial expansion in Europe and across the Mediterranean, and its development of mining, led to it becoming the greatest producer of lead during the classical era, with an estimated annual output peaking at 80,000 tonnes. Like their predecessors, the Romans obtained lead mostly as a by-product of silver smelting. Lead mining occurred in central Europe, Britain, Balkans, Greece, Anatolia, Hispania, the latter accounting for 40% of world production.
+
+Lead tablets were commonly used as a material for letters. Lead coffins, cast in flat sand forms and with interchangeable motifs to suit the faith of the deceased, were used in ancient Judea. Lead was used to make sling bullets from the 5th century BC. In Roman times, lead sling bullets were amply used, and were effective at a distance of between 100 and 150 meters. The Balearic slingers, used as mercenaries in Carthaginian and Roman armies, were famous for their shooting distance and accuracy.
+
+Lead was used for making water pipes in the Roman Empire; the Latin word for the metal, plumbum, is the origin of the English word "plumbing". Its ease of working, its low melting point enabling the easy fabrication of completely waterproof welded joints, and its resistance to corrosion ensured its widespread use in other applications, including pharmaceuticals, roofing, currency, warfare. Writers of the time, such as Cato the Elder, Columella, and Pliny the Elder, recommended lead (and lead-coated) vessels for the preparation of sweeteners and preservatives added to wine and food. The lead conferred an agreeable taste due to the formation of "sugar of lead" (lead(II) acetate), whereas copper vessels imparted a bitter flavor through verdigris formation.
+
+The Roman author Vitruvius reported the health dangers of lead and modern writers have suggested that lead poisoning played a major role in the decline of the Roman Empire. Other researchers have criticized such claims, pointing out, for instance, that not all abdominal pain is caused by lead poisoning. According to archaeological research, Roman lead pipes increased lead levels in tap water but such an effect was "unlikely to have been truly harmful". When lead poisoning did occur, victims were called "saturnine", dark and cynical, after the ghoulish father of the gods, Saturn. By association, lead was considered the father of all metals. Its status in Roman society was low as it was readily available and cheap.
+
+=== Confusion with tin and antimony ===
+Since the Bronze Age, metallurgists and engineers have understood the difference between rare and valuable tin, essential for alloying with copper to produce tough and corrosion resistant bronze, and 'cheap and cheerful' lead. However, the nomenclature in some languages is similar.  Romans called lead plumbum nigrum ("black lead"), and tin plumbum candidum ("bright lead"). The association of lead and tin can be seen in other languages: the word olovo in Czech translates to "lead", but in Russian, its cognate олово (olovo) means "tin". To add to the confusion, lead bore a close relation to antimony: both elements commonly occur as sulfides (galena and stibnite), often together. Pliny incorrectly wrote that stibnite would give lead on heating, instead of antimony. In countries such as Turkey and India, the originally Persian name surma (Persian: سرمه) came to refer to either antimony sulfide or lead sulfide, and in some languages, such as Russian, gave its name to antimony (сурьма).
+
+== Middle Ages and the Renaissance ==

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+---
+title: "History of lead"
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+source: "https://en.wikipedia.org/wiki/History_of_lead"
+category: "reference"
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+date_saved: "2026-05-05T16:15:22.223075+00:00"
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+---
+
+Lead mining in Western Europe declined after the fall of the Western Roman Empire, with Al-Andalus being the only region having a significant output. The largest production of lead occurred in South Asia and East Asia, especially China and India, where lead mining grew rapidly.
+In Europe, lead production began to increase in the 11th and 12th centuries, when it was again used for roofing and piping. Starting in the 13th century, lead was used to create stained glass. In the European and Muslim traditions of alchemy, lead (symbol ♄ in the European tradition) was considered an impure base metal which, by the separation, purification and balancing of its constituent essences, could be transformed to pure and incorruptible gold. During the period, lead was used increasingly for adulterating wine. The use of such wine was forbidden for use in Christian rites by a papal bull in 1498, but it continued to be imbibed and resulted in mass poisonings up to the late 18th century. Lead was a key material in parts of the printing press, and lead dust was commonly inhaled by print workers, causing lead poisoning. Lead also became the chief material for making bullets for firearms: it was cheap, less damaging to iron gun barrels, had a higher density (which allowed for better retention of velocity), and its lower melting point made the production of bullets easier as they could be made using a wood fire. Lead, in the form of Venetian ceruse, was extensively used in cosmetics by Western European aristocracy as whitened faces were regarded as a sign of modesty. This practice later expanded to white wigs and eyeliners, and only faded out with the French Revolution in the late 18th century. A similar fashion appeared in Japan in the 18th century with the emergence of the geishas, a practice that continued long into the 20th century. The white faces of women "came to represent their feminine virtue as Japanese women", with lead commonly used in the whitener.
+
+== Outside Europe and Asia ==
+In the New World, lead production was recorded soon after the arrival of European settlers. The earliest record dates to 1621 in the English Colony of Virginia, fourteen years after its foundation. In Australia, the first mine opened by colonists on the continent was a lead mine, in 1841. In Africa, lead mining and smelting were known in the Benue Trough and the lower Congo Basin, where lead was used for trade with Europeans, and as a currency by the 17th century, well before the scramble for Africa.
+
+== Industrial Revolution ==
+
+In the second half of the 18th century, Britain, and later continental Europe and the United States, experienced the Industrial Revolution. This was the first time during which lead production rates exceeded those of Rome. Britain was the leading producer, losing this status by the mid-19th century with the depletion of its mines and the development of lead mining in Germany, Spain, and the United States. By 1900, the United States was the leader in global lead production, and other non-European nations—Canada, Mexico, and Australia—had begun significant production; production outside Europe exceeded that within. A great share of the demand for lead came from plumbing and painting—lead paints were in regular use. At this time, more (working class) people were exposed to the metal and lead poisoning cases escalated. This led to research into the effects of lead intake. Lead was proven to be more dangerous in its fume form than as a solid metal. Lead poisoning and gout were linked; British physician Alfred Baring Garrod noted a third of his gout patients were plumbers and painters. The effects of chronic ingestion of lead, including mental disorders, were also studied in the 19th century. The first laws aimed at decreasing lead poisoning in factories were enacted during the 1870s and 1880s in the United Kingdom.
+
+== Modern era ==
+Further evidence of the threat that lead posed to humans was discovered in the late 19th and early 20th centuries. Mechanisms of harm were better understood, lead blindness was documented, and the element was phased out of public use in the United States and Europe. The United Kingdom introduced mandatory factory inspections in 1878 and appointed the first Medical Inspector of Factories in 1898; as a result, a 25-fold decrease in lead poisoning incidents from 1900 to 1944 was reported. Most European countries banned lead paint—commonly used because of its opacity and water resistance—for interiors by 1930.
+The last major human exposure to lead was the addition of tetraethyllead to gasoline as an antiknock agent, a practice that originated in the United States in 1921.  It was phased out in the United States and the European Union by 2000.
+In the 1970s, the United States and Western European countries introduced legislation to reduce lead air pollution. The impact was significant: while a study conducted by the Centers for Disease Control and Prevention in the United States in 1976–1980 showed that 77.8% of the population had elevated blood lead levels, in 1991–1994, a study by the same institute showed the share of people with such high levels dropped to 2.2%. The main product made of lead by the end of the 20th century was the lead–acid battery.
+From 1960 to 1990, lead output in the Western Bloc grew by about 31%. The share of the world's lead production by the Eastern Bloc increased from 10% to 30%, from 1950 to 1990, with the Soviet Union being the world's largest producer during the mid-1970s and the 1980s, and China starting major lead production in the late 20th century. Unlike the European communist countries, China was largely unindustrialized by the mid-20th century; in 2004, China surpassed Australia as the largest producer of lead. As was the case during European industrialization, lead has had a negative effect on health in China.
+
+== Notes ==
+
+== References ==
+
+== Bibliography ==

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+---
+title: "History of molecular theory"
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+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:23.565196+00:00"
+instance: "kb-cron"
+---
+
+In chemistry, the history of molecular theory traces the origins of the concept or idea of the existence of strong chemical bonds between two or more atoms.
+A modern conceptualization of molecules began to develop in the 19th century along with experimental evidence for pure chemical elements and how individual atoms of different chemical elements such as hydrogen and oxygen can combine to form chemically stable molecules such as water molecules.
+
+== Ancient world ==
+The modern concept of molecules can be traced back towards pre-scientific and Greek philosophers such as Leucippus and Democritus who argued that all the universe is composed of atoms and voids. 
+Circa 450 BC Empedocles imagined fundamental elements (fire (), earth (), air (), and water ()) and "forces" of attraction and repulsion allowing the elements to interact. Prior to this, Heraclitus had claimed that fire or change was fundamental to our existence, created through the combination of opposite properties.  
+In the Timaeus, Plato, following Pythagoras, considered mathematical entities such as number, point, line and triangle as the fundamental building blocks or elements of this ephemeral world, and considered the four elements of fire, air, water and earth as states of substances through which the true mathematical principles or elements would pass. A fifth element, the incorruptible quintessence aether, was considered to be the fundamental building block of the heavenly bodies. 
+The viewpoint of Leucippus and Empedocles, along with the aether, was accepted by Aristotle and passed to medieval and renaissance Europe. 
+
+=== Greek atomism ===
+The earliest views on the shapes and connectivity of atoms was that proposed by Leucippus, Democritus, and Epicurus who reasoned that the solidness of the material corresponded to the shape of the atoms involved.  Thus, iron atoms are solid and strong with hooks that lock them into a solid; water atoms are smooth and slippery; salt atoms, because of their taste, are sharp and pointed; and air atoms are light and whirling, pervading all other materials.  
+It was Democritus that was the main proponent of this view.  Using analogies based on the experiences of the senses, he gave a picture or an image of an atom in which atoms were distinguished from each other by their shape, their size, and the arrangement of their parts.  Moreover, connections were explained by material links in which single atoms were supplied with attachments: some with hooks and eyes others with balls and sockets (see diagram).
+
+== 17th century ==
+With the rise of scholasticism and the decline of the Roman Empire, the atomic theory was abandoned for many ages in favor of the various four element theories and later alchemical theories. The 17th century, however, saw a resurgence in the atomic theory primarily through the works of Gassendi and Newton. 
+Among other scientists of that time Gassendi deeply studied ancient history, wrote major works about Epicurus's natural philosophy and was a persuasive propagandist on its behalf. He reasoned that to account for the size and shape of atoms moving in a void could account for the properties of matter.  Heat was due to small, round atoms; cold, to pyramidal atoms with sharp points, which accounted for the pricking sensation of severe cold; and solids were held together by interlacing hooks. 
+Newton, though he acknowledged the various atom attachment theories in vogue at the time, i.e. "hooked atoms", "glued atoms" (bodies at rest), and the "stick together by conspiring motions" theory, rather believed, as famously stated in "Query 31" of his 1704 Opticks, that particles attract one another by some force, which "in immediate contact is extremely strong, at small distances performs the chemical operations, and reaches not far from particles with any sensible effect."
+In a more concrete manner, however, the concept of aggregates or units of bonded atoms, i.e. "molecules", traces its origins to Robert Boyle's 1661 hypothesis, in his famous treatise The Sceptical Chymist, that matter is composed of clusters of particles and that chemical change results from the rearrangement of the clusters.  Boyle argued that matter's basic elements consisted of various sorts and sizes of particles, called "corpuscles", which were capable of arranging themselves into groups.
+In 1680, using the corpuscular theory as a basis, French chemist Nicolas Lemery stipulated that the acidity of any substance consisted in its pointed particles, while alkalis were endowed with pores of various sizes.  A molecule, according to this view, consisted of corpuscles united through a geometric locking of points and pores.
+
+== 18th century ==

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+title: "History of molecular theory"
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+---
+
+An early precursor to the idea of bonded "combinations of atoms", was the theory of "combination via chemical affinity".  For example, in 1718, building on Boyle's conception of combinations of clusters, the French chemist Étienne François Geoffroy developed theories of chemical affinity to explain combinations of particles, reasoning that a certain alchemical "force" draws certain alchemical components together.  Geoffroy's name is best known in connection with his tables of "affinities" (tables des rapports), which he presented to the French Academy in 1718 and 1720.
+These were lists, prepared by collating observations on the actions of substances one upon another, showing the varying degrees of affinity exhibited by analogous bodies for different reagents.  These tables retained their vogue for the rest of the century, until displaced by the profounder conceptions introduced by CL Berthollet.
+In 1738, Swiss physicist and mathematician Daniel Bernoulli published Hydrodynamica, which laid the basis for the kinetic theory of gases.  In this work, Bernoulli positioned the argument, still used to this day, that gases consist of great numbers of molecules moving in all directions, that their impact on a surface causes the gas pressure that we feel, and that what we experience as heat is simply the kinetic energy of their motion. The theory was not immediately accepted, in part because conservation of energy had not yet been established, and it was not obvious to physicists how the collisions between molecules could be perfectly elastic.
+In 1789, William Higgins published views on what he called combinations of "ultimate" particles, which foreshadowed the concept of valency bonds.  If, for example, according to Higgins, the force between the ultimate particle of oxygen and the ultimate particle of nitrogen were 6, then the strength of the force would be divided accordingly, and similarly for the other combinations of ultimate particles:
+
+== 19th century ==
+
+Similar to these views, in 1803 John Dalton took the atomic weight of hydrogen, the lightest element, as unity, and determined, for example, that the ratio for nitrous anhydride was 2 to 3 which gives the formula N2O3. Dalton incorrectly imagined that atoms "hooked" together to form molecules. Later, in 1808, Dalton published his famous diagram of combined "atoms":
+Amedeo Avogadro created the word "molecule". His 1811 paper "Essay on Determining the Relative Masses of the Elementary Molecules of Bodies", he essentially states, i.e. according to Partington's A Short History of Chemistry, that:
+
+The smallest particles of gases are not necessarily simple atoms, but are made up of a certain number of these atoms united by attraction to form a single molecule.
+Note that this quote is not a literal translation.  Avogadro uses the name "molecule" for both atoms and molecules.  Specifically, he uses the name "elementary molecule" when referring to atoms and to complicate the matter also speaks of "compound molecules" and "composite molecules".
+During his stay in Vercelli, Avogadro wrote a concise note (memoria) in which he declared the hypothesis of what we now call Avogadro's law: equal volumes of gases, at the same temperature and pressure, contain the same number of molecules.  This law implies that the relationship occurring between the weights of same volumes of different gases, at the same temperature and pressure, corresponds to the relationship between respective molecular weights. Hence, relative molecular masses could now be calculated from the masses of gas samples.
+Avogadro developed this hypothesis to reconcile Joseph Louis Gay-Lussac's 1808 law on volumes and combining gases with Dalton's 1803 atomic theory. The greatest difficulty Avogadro had to resolve was the huge confusion at that time regarding atoms and molecules—one of the most important contributions of Avogadro's work was clearly distinguishing one from the other, admitting that simple particles too could be composed of molecules and that these are composed of atoms. Dalton, by contrast, did not consider this possibility.  Curiously, Avogadro considers only molecules containing even numbers of atoms; he does not say why odd numbers are left out.
+In 1826, building on the work of Avogadro, the French chemist Jean-Baptiste Dumas states:
+
+Gases in similar circumstances are composed of molecules or atoms placed at the same distance, which is the same as saying that they contain the same number in the same volume.
+In coordination with these concepts, in 1833 the French chemist Marc Antoine Auguste Gaudin presented a clear account of Avogadro's hypothesis, regarding atomic weights, by making use of "volume diagrams", which clearly show both semi-correct molecular geometries, such as a linear water molecule, and correct molecular formulas, such as H2O:
+
+In two papers outlining his "theory of atomicity of the elements" (1857–58), Friedrich August Kekulé was the first to offer a theory of how every atom in an organic molecule was bonded to every other atom.  He proposed that carbon atoms were tetravalent, and could bond to themselves to form the carbon skeletons of organic molecules.
+In 1856, Scottish chemist Archibald Couper began research on the bromination of benzene at the laboratory of Charles Wurtz in Paris.  One month after Kekulé's second paper appeared, Couper's independent and largely identical theory of molecular structure was published.  He offered a very concrete idea of molecular structure, proposing that atoms joined to each other like modern-day Tinkertoys in specific three-dimensional structures. Couper was the first to use lines between atoms, in conjunction with the older method of using brackets, to represent bonds, and also postulated straight chains of atoms as the structures of some molecules, ring-shaped molecules of others, such as in tartaric acid and cyanuric acid.  In later publications, Couper's bonds were represented using straight dotted lines (although it is not known if this is the typesetter's preference) such as with alcohol and oxalic acid below:
+
+In 1861, an unknown Vienna high-school teacher named Joseph Loschmidt published, at his own expense, a booklet entitled Chemische Studien I, containing pioneering molecular images which showed both "ringed" structures as well as double-bonded structures, such as:

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+---
+title: "History of molecular theory"
+chunk: 3/4
+source: "https://en.wikipedia.org/wiki/History_of_molecular_theory"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:23.565196+00:00"
+instance: "kb-cron"
+---
+
+Loschmidt also suggested a possible formula for benzene, but left the issue open.  The first proposal of the modern structure for benzene was due to Kekulé, in 1865.  The cyclic nature of benzene was finally confirmed by the crystallographer Kathleen Lonsdale. Benzene presents a special problem in that, to account for all the bonds, there must be alternating double carbon bonds:
+
+In 1865, German chemist August Wilhelm von Hofmann was the first to make stick-and-ball molecular models, which he used in lecture at the Royal Institution of Great Britain, such as methane shown below:
+
+The basis of this model followed the earlier 1855 suggestion by his colleague William Odling that carbon is tetravalent. Hofmann's color scheme, to note, is still used to this day: carbon = black, nitrogen = blue, oxygen = red, chlorine = green,  sulfur = yellow, hydrogen = white.  The deficiencies in Hofmann's model were essentially geometric: carbon bonding was shown as planar, rather than tetrahedral, and the atoms were out of proportion, e.g. carbon was smaller in size than the hydrogen.
+In 1864, Scottish organic chemist Alexander Crum Brown began to draw pictures of molecules, in which he enclosed the symbols for atoms in circles, and used broken lines to connect the atoms together in a way that satisfied each atom's valence.
+The year 1873, by many accounts, was a seminal point in the history of the development of the concept of the "molecule".  In this year, the renowned Scottish physicist James Clerk Maxwell published his famous thirteen page article 'Molecules' in the September issue of Nature.  In the opening section to this article, Maxwell clearly states:
+
+An atom is a body which cannot be cut in two; a molecule is the smallest possible portion of a particular substance.
+After speaking about the atomic theory of Democritus, Maxwell goes on to tell us that the word 'molecule' is a modern word.  He states, "it does not occur in Johnson's Dictionary.  The ideas it embodies are those belonging to modern chemistry."  We are told that an 'atom' is a material point, invested and surrounded by 'potential forces' and that when 'flying molecules' strike against a solid body in constant succession it causes what is called pressure of air and other gases.  At this point, however, Maxwell notes that no one has ever seen or handled a molecule.
+In 1874, Jacobus Henricus van 't Hoff and Joseph Achille Le Bel independently proposed that the phenomenon of optical activity could be explained by assuming that the chemical bonds between carbon atoms and their neighbors were directed towards the corners of a regular tetrahedron. This led to a better understanding of the three-dimensional nature of molecules.
+Emil Fischer developed the Fischer projection technique for viewing 3-D molecules on a 2-D sheet of paper:
+
+In 1898, Ludwig Boltzmann, in his Lectures on Gas Theory, used the theory of valence to explain the phenomenon of gas phase molecular dissociation, and in doing so drew one of the first rudimentary yet detailed atomic orbital overlap drawings.  Noting first the known fact that molecular iodine vapor dissociates into atoms at higher temperatures, Boltzmann states that we must explain the existence of molecules composed of two atoms, the "double atom" as Boltzmann calls it, by an attractive force acting between the two atoms.  Boltzmann states that this chemical attraction, owing to certain facts of chemical valence, must be associated with a relatively small region on the surface of the atom called the sensitive region.
+Boltzmann states that this "sensitive region" will lie on the surface of the atom, or may partially lie inside the atom, and will firmly be connected to it.  Specifically, he states "only when two atoms are situated so that their sensitive regions are in contact, or partly overlap, will there be a chemical attraction between them.  We then say that they are chemically bound to each other."  This picture is detailed below, showing the α-sensitive region of atom-A overlapping with the β-sensitive region of atom-B:
+
+== 20th century ==
+In the early 20th century, the American chemist Gilbert N. Lewis began to use dots in lecture, while teaching undergraduates at Harvard, to represent the electrons around atoms.  His students favored these drawings, which stimulated him in this direction.  From these lectures, Lewis noted that elements with a certain number of electrons seemed to have a special stability.  This phenomenon was pointed out by the German chemist Richard Abegg in 1904, to which Lewis referred to as "Abegg's law of valence" (now generally known as Abegg's rule).  To Lewis it appeared that once a core of eight electrons has formed around a nucleus, the layer is filled, and a new layer is started.  Lewis also noted that various ions with eight electrons also seemed to have a special stability. On these views, he proposed the rule of eight or octet rule: Ions or atoms with a filled layer of eight electrons have a special stability.
+Moreover, noting that a cube has eight corners Lewis envisioned an atom as having eight sides available for electrons, like the corner of a cube.  Subsequently, in 1902 he devised a conception in which cubic atoms can bond on their sides to form cubic-structured molecules.
+In other words, electron-pair bonds are formed when two atoms share an edge, as in structure C below. This results in the sharing of two electrons.  Similarly, charged ionic-bonds are formed by the transfer of an electron from one cube to another, without sharing an edge A. An intermediate state B where only one corner is shared was also postulated by Lewis.

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+---
+title: "History of molecular theory"
+chunk: 4/4
+source: "https://en.wikipedia.org/wiki/History_of_molecular_theory"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:23.565196+00:00"
+instance: "kb-cron"
+---
+
+Hence, double bonds are formed by sharing a face between two cubic atoms. This results in the sharing of four electrons.
+In 1913, while working as the chair of the department of chemistry at the University of California, Berkeley, Lewis read a preliminary outline of paper by an English graduate student, Alfred Lauck Parson, who was visiting Berkeley for a year.  In this paper, Parson suggested that the electron is not merely an electric charge but is also a small magnet (or "magneton" as he called it) and furthermore that a chemical bond results from two electrons being shared between two atoms.  This, according to Lewis, meant that bonding occurred when two electrons formed a shared edge between two complete cubes.
+On these views, in his famous 1916 article The Atom and the Molecule, Lewis introduced the "Lewis structure" to represent atoms and molecules, where dots represent electrons and lines represent covalent bonds.  In this article, he developed the concept of the electron-pair bond, in which two atoms may share one to six electrons, thus forming the single electron bond, a single bond, a double bond, or a triple bond.
+
+In Lewis' own words:
+
+An electron may form a part of the shell of two different atoms and cannot be said to belong to either one exclusively.
+Moreover, he proposed that an atom tended to form an ion by gaining or losing the number of electrons needed to complete a cube.  Thus, Lewis structures show each atom in the structure of the molecule using its chemical symbol. Lines are drawn between atoms that are bonded to one another; occasionally, pairs of dots are used instead of lines.  Excess electrons that form lone pairs are represented as pair of dots, and are placed next to the atoms on which they reside:
+
+To summarize his views on his new bonding model, Lewis states:
+
+Two atoms may conform to the rule of eight, or the octet rule, not only by the transfer of electrons from one atom to another, but also by sharing one or more pairs of electrons...Two electrons thus coupled together, when lying between two atomic centers, and held jointly in the shells of the two atoms, I have considered to be the chemical bond. We thus have a concrete picture of that physical entity, that "hook and eye" which is part of the creed of the organic chemist.
+The following year, in 1917, an unknown American undergraduate chemical engineer named Linus Pauling was learning the Dalton hook-and-eye bonding method at the Oregon Agricultural College, which was the vogue description of bonds between atoms at the time. Each atom had a certain number of hooks that allowed it to attach to other atoms, and a certain number of eyes that allowed other atoms to attach to it. A chemical bond resulted when a hook and eye connected.  Pauling, however, wasn't satisfied with this archaic method and looked to the newly emerging field of quantum physics for a new method.
+In 1927, the physicists Fritz London and Walter Heitler applied the new quantum mechanics to the deal with the saturable, nondynamic forces of attraction and repulsion, i.e., exchange forces, of the hydrogen molecule.  Their valence bond treatment of this problem, in their joint paper, was a landmark in that it brought chemistry under quantum mechanics.  Their work was an influence on Pauling, who had just received his doctorate and visited Heitler and London in Zürich on a Guggenheim Fellowship.
+Subsequently, in 1931, building on the work of Heitler and London and on theories found in Lewis' famous article, Pauling published his ground-breaking article "The Nature of the Chemical Bond" (see: manuscript) in which he used quantum mechanics to calculate properties and structures of molecules, such as angles between bonds and rotation about bonds.  On these concepts, Pauling developed hybridization theory to account for bonds in molecules such as CH4, in which four sp³ hybridised orbitals are overlapped by hydrogen's 1s orbital, yielding four sigma (σ) bonds. The four bonds are of the same length and strength, which yields a molecular structure as shown below:
+
+Owing to these exceptional theories, Pauling won the 1954 Nobel Prize in Chemistry. Notably he has been the only person to ever win two unshared Nobel Prizes, winning the Nobel Peace Prize in 1963.
+In 1926, French physicist Jean Perrin received the Nobel Prize in physics for proving, conclusively, the existence of molecules.  He did this by calculating the Avogadro number using three different methods, all involving liquid phase systems.  First, he used a gamboge soap-like emulsion, second by doing experimental work on Brownian motion, and third by confirming Einstein's theory of particle rotation in the liquid phase.
+In 1937, chemist K.L. Wolf introduced the concept of supermolecules (Übermoleküle) to describe hydrogen bonding in acetic acid dimers.  This would eventually lead to the area of supermolecular chemistry, which is the study of non-covalent bonding.
+In 1951, physicist Erwin Wilhelm Müller invents the field ion microscope and is the first to see atoms, e.g. bonded atomic arrangements at the tip of a metal point.
+In 1999, researchers from the University of Vienna reported results from experiments on wave-particle duality for C60 molecules.  The data published by Anton Zeilinger et al. were consistent with Louis de Broglie's matter waves. This experiment was noted for extending the applicability of wave–particle duality by about one order of magnitude in the macroscopic direction.
+In 2009, researchers from IBM managed to take the first picture of a real molecule. Using an atomic force microscope every single atom and bond of a pentacene molecule could be imaged.
+
+== See also ==
+History of chemistry
+History of quantum mechanics
+History of thermodynamics
+History of molecular biology
+Kinetic theory of gases
+Atomic theory
+
+== References ==
+
+== Further reading ==
+
+== External links ==
+Geometric Structures of Molecules - Middlebury College
+Atoms and Molecules - McMaster University
+3D Molecule Viewer - The Wileys Family
+Molecule of the Month - School of Chemistry, University of Bristol
+[1] - Eric Scerri's history & philosophy of chemistry website
+
+=== Types ===
+Antibody Molecule - The National Health Museum
+15 Types of Molecules - IUPAC Definitions
+
+=== Definitions ===
+Molecule Definition - Frostburg State University (Department of Chemistry)
+Definition of Molecule - IUPAC
+
+=== Articles ===
+Molecules Used to Make Nano-sized Containers - TRN Newswire
+Molecular Computer Processors - HP Labs

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+---
+title: "History of spectroscopy"
+chunk: 1/3
+source: "https://en.wikipedia.org/wiki/History_of_spectroscopy"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:24.945489+00:00"
+instance: "kb-cron"
+---
+
+Modern spectroscopy in the Western world started in the 17th century. New designs in optics, specifically prisms, enabled systematic observations of the solar spectrum. Isaac Newton first applied the word spectrum to describe the rainbow of colors that combine to form white light. During the early 1800s, Joseph von Fraunhofer conducted experiments with dispersive spectrometers that enabled spectroscopy to become a more precise and quantitative scientific technique. Since then, spectroscopy has played and continues to play a significant role in chemistry, physics and astronomy. Fraunhofer observed and measured dark lines in the Sun's spectrum, which now bear his name although several of them were observed earlier by Wollaston.
+
+== Origins and experimental development ==
+The Romans were already familiar with the ability of a prism to generate a rainbow of colors. Newton is traditionally regarded as the founder of spectroscopy, but he was not the first scientist who studied and reported on the solar spectrum. The works of Athanasius Kircher (1646), Jan Marek Marci (1648), Robert Boyle (1664), and Francesco Maria Grimaldi (1665), predate Newton's optics experiments (1666–1672). Newton published his experiments and theoretical explanations of dispersion of light in his Opticks. His experiments demonstrated that white light could be split up into component colors by means of a prism and that these components could be recombined to generate white light. He demonstrated that the prism is not imparting or creating the colors but rather separating constituent parts of the white light. Newton's corpuscular theory of light was gradually succeeded by the wave theory. It was not until the 19th century that the quantitative measurement of dispersed light was recognized and standardized. As with many subsequent spectroscopy experiments, Newton's sources of white light included flames and stars, including the Sun. Subsequent studies of the nature of light include those of Hooke, Huygens, Young. Subsequent experiments with prisms provided the first indications that spectra were associated uniquely with chemical constituents. Scientists observed the emission of distinct patterns of colour when salts were added to alcohol flames.
+
+=== Early 19th century (1800–1829) ===
+
+In 1802, William Hyde Wollaston built a spectrometer, but he observed the spectrum directly with his eye rather than projecting on a screen. Upon use, Wollaston realized that within the colors were dark bands in the sun's spectrum.
+In 1815, independently and unaware of Wollaston's paper Joseph von Fraunhofer used a better spectrometer and observed 754 lines now called Fraunhofer lines.
+Fraunhofer replaced the prism with a diffraction grating as the source of wavelength dispersion. Fraunhofer built off the theories of light interference developed by Thomas Young, François Arago and Augustin-Jean Fresnel. He conducted his own experiments to demonstrate the effect of passing light through a single rectangular slit, two slits, and so forth, eventually developing a means of closely spacing thousands of slits to form a diffraction grating. The interference achieved by a diffraction grating both improves the spectral resolution over a prism and allows for the dispersed wavelengths to be quantified. Fraunhofer's establishment of a quantified wavelength scale paved the way for matching spectra observed in multiple laboratories, from multiple sources (flames and the sun) and with different instruments. Fraunhofer made and published systematic observations of the solar spectrum, and the dark bands he observed and specified the wavelengths of are still known as Fraunhofer lines.
+Throughout the early 1800s, a number of scientists pushed the techniques and understanding of spectroscopy forward. In the 1820s, both John Herschel and William H. F. Talbot made systematic observations of salts using flame spectroscopy.
+
+=== Mid-19th century (1830–1869) ===
+In 1835, Charles Wheatstone reported that different metals could be easily distinguished by the different bright lines in the emission spectra of their sparks, thereby introducing an alternative mechanism to flame spectroscopy. In 1849, J. B. L. Foucault experimentally demonstrated that absorption and emission lines appearing at the same wavelength are both due to the same material, with the difference between the two originating from the temperature of the light source. In 1853, the Swedish physicist Anders Jonas Ångström presented observations and theories about gas spectra in his work Optiska Undersökningar (Optical investigations) to the  Royal Swedish Academy of Sciences. Ångström postulated that an incandescent gas emits luminous rays of the same wavelength as those it can absorb. Ångström was unaware of Foucalt's experimental results. At the same time George Stokes and William Thomson (Kelvin) were discussing similar postulates. Ångström also measured the emission spectrum from hydrogen later labeled the Balmer lines. In 1854 and 1855, David Alter published observations on the spectra of metals and gases, including an independent observation of the Balmer lines of hydrogen.
+
+The systematic attribution of spectra to chemical elements began in the 1860s with the work of German physicists Robert Bunsen and Gustav Kirchhoff, who found that Fraunhofer lines correspond to emission spectral lines observed in laboratory light sources. This laid way for spectrochemical analysis in laboratory and astrophysical science. Bunsen and Kirchhoff applied the optical techniques of Fraunhofer, Bunsen's improved flame source and a highly systematic experimental procedure to a detailed examination of the spectra of chemical compounds. They established the linkage between chemical elements and their unique spectral patterns. In the process, they established the technique of analytical spectroscopy. In 1860, they published their findings on the spectra of eight elements and identified these elements' presence in several natural compounds. They demonstrated that spectroscopy could be used for trace chemical analysis and several of the chemical elements they discovered were previously unknown. Kirchhoff and Bunsen also definitively established the link between absorption and emission lines, including attributing solar absorption lines to particular elements based on their corresponding spectra. Kirchhoff went on to contribute fundamental research on the nature of spectral absorption and emission, including what is now known as Kirchhoff's law of thermal radiation. Kirchhoff's applications of this law to spectroscopy are captured in three laws of spectroscopy:

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+---
+title: "History of spectroscopy"
+chunk: 2/3
+source: "https://en.wikipedia.org/wiki/History_of_spectroscopy"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:24.945489+00:00"
+instance: "kb-cron"
+---
+
+An incandescent solid, liquid or gas under high pressure emits a continuous spectrum.
+A hot gas under low pressure emits a "bright-line" or emission-line spectrum.
+A continuous spectrum source viewed through a cool, low-density gas produces an absorption-line spectrum.
+In the 1860s the husband-and-wife team of William and Margaret Huggins used spectroscopy to determine that the stars were composed of the same elements as found on earth. They also used the non-relativistic Doppler shift (redshift) equation on the spectrum of the star Sirius in 1868 to determine its axial speed. They were the first to take a spectrum of a planetary nebula when the Cat's Eye Nebula (NGC 6543) was analyzed. Using spectral techniques, they were able to distinguish nebulae from stars.
+August Beer observed a relationship between light absorption and concentration and created the color comparator which was later replaced by a more accurate device called the spectrophotometer.
+
+=== Late 19th century (1870–1899) ===
+In the 19th century new developments such as the discovery of photography, Rowland's invention of the concave diffraction grating, and Schumann's works on discovery of vacuum ultraviolet (fluorite for prisms and lenses, low-gelatin photographic plates and absorption of UV in air below 185 nm) made advance to shorter wavelengths very fast.
+In 1871,  Stoney suggested using a wavenumber scale for spectra and Hartley followed up, finding constant wave-number differences in the triplets of zinc.
+
+Liveing and
+Dewar observed that alkali spectra appeared to form a series and Alfred Cornu found similar structure in the spectra of thallium and aluminum, setting the stage for Balmer to discover a relation connecting wavelengths in the visible hydrogen spectrum. In 1890, Kayser and Runge organized the series reported by Liveing and Dewar using names like 'Principal', 'diffuse', and 'sharp' series. Rydberg gave a formula for wave-numbers of all spectral series of all the alkalis and hydrogen. 
+In 1895, the German physicist Wilhelm Conrad Röntgen discovered and extensively studied X-rays, which were later used in X-ray spectroscopy.  One year later, in 1896, French physicist Antoine Henri Becquerel discovered radioactivity, and Dutch physicist Pieter Zeeman observed spectral lines being split by a magnetic field.
+In 1897, theoretical physicist, Joseph Larmor explained the splitting of the spectral lines in a magnetic field by the oscillation of electrons.
+Physicist, Joseph Larmor, created the first solar system model of the atom in 1897. He also postulated the proton, calling it a "positive electron." He said the destruction of this type of atom making up matter "is an occurrence of infinitely small probability."
+
+=== Early 20th century (1900–1950) ===
+The first decade of the 20th century brought the basics of quantum theory (Planck, Einstein) and interpretation of spectral series of hydrogen by Lyman in VUV and by Paschen in infrared. Ritz formulated the combination principle.
+John William Nicholson had created an atomic model in 1912, a year before Niels Bohr, that was both nuclear and quantum in which he showed that electron oscillations in his atom matched the solar and nebular spectral lines. Bohr had been working on his atom during this period, but Bohr's model had only a single ground state and no spectra until he incorporated the Nicholson model and referenced the Nicholson papers in his model of the atom.
+In 1913, Bohr formulated his quantum mechanical model of atom. This stimulated empirical term analysis. Bohr published a theory of the hydrogen-like atoms that could explain the observed wavelengths of spectral lines due to electrons transitioning from different energy states. In 1937 "E. Lehrer created the first fully-automated spectrometer" to help more accurately measure spectral lines. With the development of more advanced instruments such as photo-detectors scientists were then able to more accurately measure specific wavelength absorption of substances.
+
+== Development of quantum mechanics ==
+Between 1920 and 1930 fundamental concepts of quantum mechanics were developed by Pauli, Heisenberg, Schrödinger, and Dirac. Understanding of the spin and exclusion principle allowed conceiving how electron shells of atoms are filled with the increasing atomic number.
+
+== Multiply ionized atoms ==
+This branch of spectroscopy deals with radiation related to atoms that are stripped of several electrons (multiply ionized atoms (MIA), multiply charged ions, highly charged ions). These are observed in very hot plasmas (laboratory or astrophysical) or in accelerator experiments (beam-foil, electron beam ion trap (EBIT)). The lowest exited electron shells of such ions decay into stable ground states producing photons in VUV, EUV and soft X-ray spectral regions (so-called resonance transitions).
+
+=== Structure studies ===
+Further progress in studies of atomic structure was in tight connection with the advance to shorter wavelength in EUV region. Millikan, Sawyer, Bowen used electric discharges in vacuum to observe some emission spectral lines down to 13 nm they prescribed to stripped atoms. In 1927 Osgood and Hoag reported on grazing incidence concave grating spectrographs and photographed lines down to 4.4 nm (Kα of carbon). Dauvillier used a fatty acid crystal of large crystal grating space to extend soft x-ray spectra up to 12.1 nm, and the gap was closed. In the same period Manne Siegbahn constructed a very sophisticated grazing incidence spectrograph that enabled Ericson and Edlén to obtain spectra of vacuum spark with high quality and to reliably identify lines of multiply ionized atoms up to O VI, with five stripped electrons. Grotrian developed his graphic presentation of energy structure of the atoms. Russel and Saunders proposed their coupling scheme for the spin-orbit interaction and their generally recognized notation for spectral terms.

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+---
+title: "History of spectroscopy"
+chunk: 3/3
+source: "https://en.wikipedia.org/wiki/History_of_spectroscopy"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:24.945489+00:00"
+instance: "kb-cron"
+---
+
+=== Accuracy ===
+Theoretical quantum-mechanical calculations become rather accurate to describe the energy structure of some simple electronic configurations. The results of theoretical developments were summarized by Condon and Shortley in 1935.
+Edlén thoroughly analyzed spectra of MIA for many chemical elements and derived regularities in energy structures of MIA for many isoelectronic sequences (ions with the same number of electrons, but different nuclear charges). Spectra of rather high ionization stages (e.g. Cu XIX) were observed.
+The most exciting event was in 1942, when Edlén proved the identification of some solar coronal lines on the basis of his precise analyses of spectra of MIA. This implied that the solar corona has a temperature of a million degrees, and strongly advanced understanding of solar and stellar physics.
+After the WW II experiments on balloons and rockets were started to observe the VUV radiation of the Sun. (See X-ray astronomy). More intense research continued since 1960 including spectrometers on satellites.
+In the same period the laboratory spectroscopy of MIA becomes relevant as a diagnostic tool for hot plasmas of thermonuclear devices (see Nuclear fusion) which begun with building Stellarator in 1951 by Spitzer, and continued with tokamaks, z-pinches and the laser produced plasmas. Progress in ion accelerators stimulated beam-foil spectroscopy as a means to measure lifetimes of exited states of MIA. Many various data on highly exited energy levels, autoionization and inner-core ionization states were obtained. 
+
+=== Electron beam ion trap ===
+Simultaneously theoretical and computational approaches provided data necessary for identification of new spectra and interpretation of observed line intensities. New laboratory and theoretical data become very useful for spectral observation in space. It was a real upheaval of works on MIA in USA, England, France, Italy, Israel, Sweden, Russia and other countries
+A new page in the spectroscopy of MIA may be dated as 1986 with development of EBIT (Levine and Marrs, LLNL) due to a favorable composition of modern high technologies such as cryogenics, ultra-high vacuum, superconducting magnets, powerful electron beams and semiconductor detectors. Very quickly EBIT sources were created in many countries (see NIST summary for many details as well as reviews.)
+A wide field of spectroscopic research with EBIT is enabled including achievement of highest grades of ionization (U92+), wavelength measurement, hyperfine structure of energy levels, quantum electrodynamic studies, ionization cross-sections (CS) measurements, electron-impact excitation CS, X-ray polarization, relative line intensities, dielectronic recombination CS, magnetic octupole decay, lifetimes of forbidden transitions, charge-exchange recombination, etc.
+
+== Infrared and Raman spectroscopy ==
+Many early scientists who studied the IR spectra of compounds had to develop and build their own instruments to be able to record their measurements making it very difficult to get accurate measurements. During World War II, the U.S. government contracted different companies to develop a method for the polymerization of butadiene to create rubber, but this could only be done through analysis of C4 hydrocarbon isomers. These contracted companies started developing optical instruments and eventually created the first infrared spectrometers. With the development of these commercial spectrometers, Infrared Spectroscopy became a more popular method to determine the "fingerprint" for any molecule. Raman spectroscopy was first observed in 1928 by Sir Chandrasekhara Venkata Raman in liquid substances and also by "Grigory Landsberg and Leonid Mandelstam in crystals". Raman spectroscopy is based on the observation of the raman effect which is defined as "The intensity of the scattered light is dependent on the amount of the polarization potential change". The raman spectrum records light intensity vs. light frequency (wavenumber) and the wavenumber shift is characteristic to each individual compound.
+
+== Laser spectroscopy ==
+Laser spectroscopy is a spectroscopic technique that uses lasers to be able determine the emitted frequencies of matter. The laser was invented because spectroscopists took the concept of its predecessor, the maser, and applied it to the visible and infrared ranges of light. The maser was invented by Charles Townes and other spectroscopists to stimulate matter to determine the radiative frequencies that specific atoms and molecules emitted. While working on the maser, Townes realized that more accurate detections were possible as the frequency of the microwave emitted increased. This led to an idea a few years later to use the visible and eventually the infrared ranges of light for spectroscopy that became a reality with the help of Arthur Schawlow. Since then, lasers have gone on to significantly advance experimental spectroscopy. The laser light allowed for much higher precision experiments specifically in the uses of studying collisional effects of light as well as being able to accurately detect specific wavelengths and frequencies of light, allowing for the invention of devices such as laser atomic clocks. Lasers also made spectroscopy that used time methods more accurate by using speeds or decay times of photons at specific wavelengths and frequencies to keep time. Laser spectroscopic techniques have been used for many different applications. One example is using laser spectroscopy to detect compounds in materials. One specific method is called Laser-induced Fluorescence Spectroscopy, and uses spectroscopic methods to be able to detect what materials are in a solid, liquid, or gas, in situ. This allows for direct testing of materials, instead of having to take the material to a lab to figure out what the solid, liquid, or gas is made of.
+
+== See also ==
+List of spectroscopists
+Mass spectrometry
+History of quantum mechanics
+
+== References ==
+
+== External links ==
+MIT Spectroscopy Lab's History of Spectroscopy
+Spectroscopy Magazine's "A Timeline of Atomic Spectroscopy" Archived 2014-08-09 at the Wayback Machine

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+---
+title: "History of the Haber process"
+chunk: 1/5
+source: "https://en.wikipedia.org/wiki/History_of_the_Haber_process"
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+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:26.170591+00:00"
+instance: "kb-cron"
+---
+
+The history of the Haber process begins with the invention of the Haber process at the dawn of the twentieth century. The process allows the economical fixation of atmospheric dinitrogen in the form of ammonia, which in turn allows for the industrial synthesis of various explosives and nitrogen fertilizers, and is probably the most important industrial process developed during the twentieth century.
+Well before the start of the industrial revolution, farmers would fertilize the land in various ways, mainly using feces and urine, well aware of the benefits of an intake of essential nutrients for plant growth. Although it was frowned upon, farmers took it upon themselves to fertilize their fields using natural means and remedies that had been passed down from generation to generation. The 1840s works of Justus von Liebig identified nitrogen as one of these important nutrients. The same chemical compound could already be converted to nitric acid, the precursor of gunpowder and powerful explosives like TNT and nitroglycerine. Scientists also already knew that nitrogen formed the dominant portion of the atmosphere, but manmade chemistry had yet to establish a means to fix it.
+Then, in 1909, German chemist Fritz Haber successfully fixed atmospheric nitrogen in a laboratory. This success had extremely attractive military, industrial and agricultural applications. In 1913, barely five years later, a research team from BASF, led by Carl Bosch, developed the first industrial-scale application of the Haber process, sometimes called the Haber–Bosch process.
+The industrial production of nitrogen prolonged World War I by providing Germany with the gunpowder and explosives necessary for the war effort even though it no longer had access to guano. During the interwar period, the lower cost of ammonia extraction from the virtually inexhaustible atmospheric reservoir contributed to the development of intensive agriculture and provided support for worldwide population growth. During World War II, the efforts to industrialize the Haber process benefited greatly from the Bergius process, allowing Nazi Germany access to the synthesized fuel produced by IG Farben, thereby decreasing oil imports.
+In the early twenty-first century, the effectiveness of the Haber process (and its analogues) is such that these processes satisfy more than 99% of global demand for synthetic ammonia, a demand which exceeds 100 million tons annually. Nitrogen fertilizers and synthetic products, such as urea and ammonium nitrate, are mainstays of industrial agriculture, and are essential to the nourishment of at least two billion people. Industrial facilities using the Haber process and its analogues have a significant ecological impact. Half of the nitrogen in the great quantities of synthetic fertilizers employed today is not assimilated by plants but finds its way into rivers and the atmosphere as volatile chemical compounds.
+
+== Nitrogen sources pre-Haber process ==
+For several centuries, farmers knew that certain nutrients were essential for plant growth. In different parts of the world, farmers developed different methods of fertilizing the farmland. In China, human waste was scattered in rice fields. Justus von Liebig (1803 – 1873), German chemist and founder of industrial agriculture, claimed that England had "stolen" 3.5 million skeletons from Europe to obtain phosphorus for fertilizer. In Paris, as many as one million tons of horse dung was collected annually to fertilize city gardens. Throughout the nineteenth century, bison bones from the American West were brought back to East Coast factories for the production of phosphorus and phosphate fertilizer.
+
+From the 1820s to the 1860s, the Chincha Islands of Peru were exploited for their high quality guano deposits, which they exported to the United States, France and the United Kingdom. The guano-boom increased economic activity in Peru considerably for a few decades until all 12.5 million tons of guano deposits were exhausted.
+Research was initiated to find alternative sources of fertilizer. The Atacama Desert, at that time part of Peru, was home to significant amounts of saltpeter (sodium nitrate). At the time of the discovery of these deposits, the saltpeter had limited agricultural use. Then chemists successfully developed a process to purify the saltpeter in order to produce gunpowder. The saltpeter was also converted into nitric acid, the precursor of powerful explosives, such as nitroglycerine and dynamite. As exports from this region increased, tensions between Peru and its neighbors increased as well.
+In 1879, Bolivia, Chile, and Peru went to war over possession of Atacama Desert, the so-called "Saltpeter War". Bolivian forces were quickly defeated by the Chileans. In 1881, Chile defeated Peru and seized control of nitrate exploitation in the Atacama Desert. Consumption of Chilean saltpeter for agriculture quickly grew and Chileans standard of living rose significantly.
+Technological developments in Europe brought an end to these days. In the twentieth century, the minerals from this region "contribute[d] minimally to global nitrogen supply."

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+---
+title: "History of the Haber process"
+chunk: 2/5
+source: "https://en.wikipedia.org/wiki/History_of_the_Haber_process"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:26.170591+00:00"
+instance: "kb-cron"
+---
+
+== A pressing need ==
+In the late nineteenth century, chemists, including William Crookes, President of the British Association for the Advancement of Science in 1898, predicted that the demand for nitrogen compounds, either in the form of fertilizer or explosives, would exceed supply in the near future.
+Following the work by Claude Louis Berthollet published in 1784, chemists knew ammonia to be a nitrogen compound. Early attempts to synthesize ammonia were performed in 1795 by Georg Friedrich Hildebrandt. Several others were made during the nineteenth century.
+In the 1870s, ammonia was an unwanted byproduct of making manufactured gas. Its importance emerged later, and in the 1900s the industry modified their facilities to produce it from coke. Still, production could not meet demand.
+In 1900, Chile, with its deposits of saltpeter, produced two-thirds of all fertilizer on the planet. However, these deposits rapidly diminished, the industry was dominated by an oligopoly and the cost of saltpeter rose constantly. To ensure food security for Europe's growing population, it was essential that a new economical and reliable method of obtaining ammonia be developed.
+Issues of food security were particularly acute in Germany. Its soil was poor and the country lacked an empire. A major consumer of Chilean saltpeter, Germany saltpeter imports totaled 350,000 tonnes in 1900. Twelve years later, it imported 900,000 tonnes. The United States was in much better position due to the Guano Islands Act.
+In the years between 1890 and 1900, chemistry advanced on several fronts, and more scientists attempted to fix atmospheric nitrogen. In 1895, German chemists Adolf Frank and Nikodem Caro succeeded in reacting calcium carbide with dinitrogen to obtain calcium cyanamide, a chemical compound used as a fertilizer. Industrialization of the Frank-Caro process began in 1905. By 1918, there were 35 synthesis sites fixing 325,000 tonnes of nitrogen annually.  However, the Cyanamide process consumed large amounts of electrical power and was more labor-intensive than the Haber process. Today, cyanamide is used primarily as a herbicide.
+Wilhelm Ostwald, considered one of the best German chemists of the early twentieth century, attempted to synthesize ammonia in 1900 using an invention. He interested BASF, who asked Carl Bosch, a recently hired chemist, to validate the device.
+In 1901, Henry Le Chatelier managed to synthesize ammonia from air. After obtaining a patent, he claimed it was possible to obtain better performance by increasing the pressure. When one of his assistants was killed following the accidental explosion of a device, Le Chatelier decided to end his research.
+In 1905, Norwegian physicist Kristian Birkeland, funded by engineer and industrialist Samuel Eyde, developed the Birkeland–Eyde process which fixes atmospheric nitrogen as nitrogen oxides. The Birkeland–Eyde process requires a considerable amount of electricity, constraining possible site location; fortunately, Norway possessed several sites capable of meeting these needs. Norsk Hydro was founded 2 December 1905 to commercialize the new process. In 1911, the Norsk Hydro facility was consuming 50,000 kW, the next year, consumption doubled to 100,000 kW. By 1913, Norsk Hydro's facilities were producing 12,000 tonnes of nitrogen,  about 5 percent of the volume extracted from coke at the time.
+Similar processes were developed at the time. Schönherr, an employee of BASF, worked on a nitrogen fixation process beginning in 1905. In 1919, Schönherr's Badische process was employed at Norsk Hydro facilities. That same year, the Pauling process was used in Germany and the United States.
+All these methods were quickly supplanted by the less-expensive Haber process.
+
+== A new approach ==
+In 1905, German chemist Fritz Haber published Thermodynamik technischer Gasreaktionen (The Thermodynamics of Technical Gas Reactions), a book more concerned about the industrial application of chemistry than to its theoretical study. In it, Haber inserted the results of his study of the equilibrium equation of ammonia:
+
+N2 (g) + 3 H2 (g) ⇌ 2 NH3 (g) - ΔH
+At 1000 °C in the presence of an iron catalyst, "small" amounts of ammonia were produced from dinitrogen and dihydrogen gas. These results discouraged his further pursuit in this direction. However, in 1907, spurred by a scientific rivalry between Haber and Walther Nernst, nitrogen fixation became Haber's first priority. A few years later, Haber used results published by Nernst on the chemical equilibrium of ammonia and his own familiarity with high pressure chemistry and the liquefaction of air, to develop a new nitrogen fixation process. He had no precise information on the parameters to impose on the system, but at the conclusion of his research, he was able to establish that an effective ammonia production system must:

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+---
+title: "History of the Haber process"
+chunk: 3/5
+source: "https://en.wikipedia.org/wiki/History_of_the_Haber_process"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:26.170591+00:00"
+instance: "kb-cron"
+---
+
+operate at high pressure (on the order of 20 MPa);
+implement one or more catalysts to accelerate the synthesis of ammonia;
+operate at a high temperature (between 500 °C and 600 °C) to obtain the best efficiency in the presence of the catalyst;
+since about 5% of the N2 and H2 molecules react with each passage in the chemical reactor:
+separate the ammonia from the other molecules by liquefaction,
+withdraw ammonia continuously,
+inject the N2 and H2 that did not react into the chemical reactor again;
+recycle the heat produced.
+To overcome the problems associated with high pressure, Haber called upon the talents of Robert Le Rossignol, who designed the equipment necessary for the success of the process. Early in 1909, Haber discovered that osmium could serve as a catalyst. Later, he established that uranium could also act as a catalyst.  Haber also obtained good results with iron, nickel, manganese and calcium. In the chemical equation shown above, the direct reaction is exothermic. This heat can be used to heat the reagents before they enter the chemical reactor. Haber's team developed a system that recycles the heat produced.
+In March 1909, Haber demonstrated to his laboratory colleagues that he had finally found a process capable of fixing atmospheric dinitrogen sufficient to consider its industrialization.
+While BASF took out a patent on the Haber process, August Bernthsen, director of research at BASF, doubted the utility of it. He did not believe that BASF wanted to engage in such a project. According to Bernthsen, no industrial device was capable of withstanding such high pressure and temperature for a long enough period to pay off the investment. In addition, it appeared to him that the catalytic potential of osmium could disappear with use, which required its regular replacement despite the metal being scarce on Earth.
+However, Carl Engler, a chemist and university professor, wrote to BASF President Heinrich von Brunck to convince him to talk to Haber. Von Brunck, along with Bernthsen and Carl Bosch, went to Haber's laboratory to determine whether BASF should engage in industrialization of the process. When Bernthsen learned that he needed devices capable of supporting at least 100 atm (about 10 MPa), he exclaimed, "One hundred atmospheres! Just yesterday an autoclave at seven atmospheres exploded on us!" Before deciding, von Brunck asked for Bosch's advice.
+The latter had already worked in metallurgy, and his father had installed a mechanical workshop at home where the young Carl had learned to handle different tools. He had been working for several years on nitrogen fixation, without having obtained any significant results. He knew that processes that used electric arc furnaces, such as the Birkeland–Eyde process, required huge amounts of electricity, making them economically nonviable outside Norway. To continue to grow, BASF had to find a more economical method of fixing. Bosch said, "I think it can work. I know exactly what the steel industry can do. We should risk it."
+
+In July 1909, BASF employees came to check on Haber's success again: the laboratory equipment fixed the nitrogen from the air, in the form of liquid ammonia, at a rate of about 250 milliliters every two hours. BASF decided to industrialize the process, although it was associated with Norsk Hydro to operate the Schönherr process. Carl Bosch, future head of industrialization of the process, reported that the key factor that prompted BASF to embark on this path was the improvement of the efficiency of the catalyst.
+
+== A new field of knowledge ==
+At the time, high-pressure chemistry was a new field of knowledge, making its industrialisation all the more difficult. However, BASF had developed an industrial process for synthesizing indigo dye. This development took 15 years of work, but paid off, as this process made BASF an industrial giant.
+
+In his speech before accepting his Nobel prize in chemistry in 1931, Carl Bosch claimed that, before ammonia could be synthesized industrially, three major obstacles needed to be overcome:
+
+Obtain hydrogen and nitrogen gas at a lower cost than what was commonly available at the time,
+Manufacture efficient and stable catalysts,
+Building the apparatus.
+
+=== A satisfactory gas mixture ===
+At the time Bosch began the development of this industrial process in 1909, it was possible to obtain a sufficiently pure gas mixture of hydrogen and nitrogen in the right proportions. However, there was no source capable of supplying an industrial plant at sufficiently low cost. Developing an economical source was essential as, according to Bosch, the cost of ammonia production was mostly dependent on the cost of hydrogen.
+Bosch and his colleagues succeeded in developing a catalytic chemical process cable of supplying hydrogen to BASF's facilities, consequently providing a substitute to the chlor-alkali process. In the 21st century, the bulk of required hydrogen is produced from methane using heterogeneous catalysts, which requires considerably less energy than other methods.
+
+=== A stable and inexpensive catalyst ===
+
+When the industrialisation project started, Bosch rejected osmium as a catalyst, due its rarity. He also rejected uranium because it easily reacts with oxygen and water, both present in air
+Bosch assigned Alwin Mittasch to search for a stable and inexpensive catalyst. Together with his colleagues, they studied practically all the elements of the periodic table to find the best catalyst.  In September 1909, they discovered an iron-based compound that exhibited interesting properties. The impurities in the compound had a catalytic effect, but Mittasch did not know the exact arrangement. After two years of work, they discovered a catalyst, also iron-based, significantly less expensive and more stable than osmium. When he stopped his search for an ideal catalyst in 1920, Mittasch estimated that he had tested about 20,000 compounds. His efforts ushered in a new era in chemistry: chemists recognized the importance of promoters, impurities that increase the catalytic effect tenfold.
+According to Bosch, all iron-based catalysts used in 1931 were used in ammonia synthesis. He also mentioned that molybdenum had excellent catalytic properties.

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+---
+title: "History of the Haber process"
+chunk: 4/5
+source: "https://en.wikipedia.org/wiki/History_of_the_Haber_process"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:26.170591+00:00"
+instance: "kb-cron"
+---
+
+=== New apparatus ===
+Bosch's team also had to conceive industrial apparatus capable of working under the new conditions of the time: pressures of the order of 20 MPa and temperatures in the order of 600 °C. According to Bosch, there was no other equivalent in industry (Linde's liquefaction process, of physical nature, was the closest thing). To meet their needs, they had to set up a manufacturing workshop from scratch. Bosch and his colleagues replicated Haber's prototype to conduct their experiments. This apparatus could not operate on an industrial scale. They conceived new devices, and 24 of these were put into continuous operation for years.
+
+When Bosch believed his team had gained sufficient experience with benchtop devices, he had two larger chemical reactors built. Each was 2.44 meters high and had a wall thickness exceeding 2.5 centimeters. These cylinders were built by the best German gun manufacturer of the time: Krupp.
+During their experiments, they discovered that the supposedly strong alloys lost their elasticity under these operating conditions. Bosch spontaneously believed that chemical corrosion caused by nitrogen was responsible for this phenomenon. To confirm his suspicions, he used a novelty in the industrial setting of the time: metallographic analysis. It revealed that hydrogen at high pressure and temperature was responsible: it penetrated the steel walls of the reactor and weakened them by forming a new alloy.
+They attempted to solve this problem by reducing the temperature of the reactor, but the catalyst only worked at temperatures above 400 °C. They covered the inner reactor walls with thermal insulators, but hydrogen diffused easily through these materials, and, is an excellent thermal conductor at high pressures. They also tried various steels that were commercially available at the time, without success.
+The program was in jeopardy, and six months after the problem first appeared, there were still no viable and permanent solutions. Finally, it was Bosch that found one: separating the two functions offered by the reactor shell. The reactor shell serves to (1) maintain internal pressure, and (2) prevent the diffusion of the gaseous mixture outside of the reactor. A reactor with two walls, nested together like Russian dolls, makes it possible to separate both functions. Hydrogen diffuses across the inner walls and sees its pressure greatly reduced on the other side, where it is much less likely to corrode the interior shell. To facilitate the flow of hydrogen, the exterior walls are engraved with small gutters on their inner faces. On the other hand, it was possible for hydrogen to accumulate between the two walls. Bosch wondered how to prevent the risk of explosions caused by such pockets. The solution came to him when he realized that hydrogen could escape through the outside walls without significantly reducing the pressure in the reactor. He had small holes drilled in the outer surface. Bosch claimed that this solution was still in use in 1931. It was also possible to reduce corrosion by circulating nitrogen gas between the two walls.
+Several members of Bosch's team were veterans of the era where BASF had created various dye synthesis processes, including indigo. They knew that the development of an industrial process could take years, and so were not particularly disappointed when problems arose. However, the program moved forward regularly, which maintained the morale of the employees.
+At the time, there was no industrial pump capable of delivering pressures in the order of 20 MPa. Linde's liquefaction process, for example, used air pumps, but they were too small. Additionally, air leaks were tolerated. In the Haber-Bosch process, hydrogen leaks were not permissible due to the risk of explosion.  Additionally, any leaks increase the cost of ammonia production. After several years of work, employees under Bosch's orders managed to put into operation sealed pumps of about 2240 kW that could operate continuously for 6 months before requiring maintenance, something that had not yet been achieved.
+While Bosch and his team experimented to create new apparatus, some exploded under pressure. They would then perform an "autopsy" of the debris to determine what had caused the rupture. This allowed them to design stronger, more reliable devices. To maintain the physical integrity of the production devices, the production system had to be quickly halted in the case of breakage. They developed a set of instruments designed to continuously monitor the evolution of chemical reactions, another novelty at the time. According to Bosch, the production site had to operate continuously and smoothly, and any stoppage  at any point led to a complete shut down and it would take several hours before it could restart, making production less profitable.
+It was finally on May 7, 1911, in Oppau, Germany, that the construction of BASF's first industrial synthesis site officially began. Bosch supervised the project, ensuring its smooth running. On site, workers assembled compressors the size of locomotives, chemical reactors four times larger than those commonly used elsewhere in the chemical industry, a mini-factory to extract nitrogen from the air and purify it before injecting it into the reactors, kilometers of tubing, a complete electrical system including generators, a port shipping system attached to a marshalling yard, a laboratory operated by 180 researchers assisted by a thousand assistants, as well as housing for more than 10,000 workers.
+
+The company was able to produce ammonia industrially from 1913. The Oppau site started production on September 9. In the same year, it was able to produce up to 30 tons of ammonia per day In 1914, the plant produced 8700 tons of ammonia, which was used to supply a neighboring unit, which produced 36000 tons of ammonium sulfate.
+The Oppau site was not only an increasingly important source of revenue for BASF, as its steadily growing production was completely sold out, it also served as a laboratory. The site offered the opportunity to develop the emerging technology of high-pressure chemistry. Bosch and his colleagues encountered problems never seen before, but could explore different approaches without worrying about the costs associated with their development.

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+---
+title: "History of the Haber process"
+chunk: 5/5
+source: "https://en.wikipedia.org/wiki/History_of_the_Haber_process"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:26.170591+00:00"
+instance: "kb-cron"
+---
+
+== Notes ==
+
+== Bibliography ==
+Auger, Pierre; Grmek, Mirko D. (1969). Encyclopédie internationale des sciences et des techniques. Verona, Italy: Presses de la Cité. p. 840.
+Bensaude-Vincent, Bernadette (2008). "Fritz Haber : un criminel de guerre récompensé". La Recherche (423): 66–70. ISSN 0029-5671.
+Bensaude-Vincent, Bernadette; Stengers, Isabelle (2001). Histoire de la chimie. Sciences humaines et sociales. Paris: La Découverte/Poche. p. 364. ISBN 2-7071-3541-0.
+Bosch, Carl (1931). The Development of the Chemical High Pressure Method During the Establishment of the New Ammonia Industry (PDF). Oslo, Sweden: Nobel Foundation. p. 45.
+Considine, Glenn D.; Kulik, Peter H. (2002). Ammonia. Vol. Van Nostrand's Scientific Encyclopedia, Ninth Edition. Canada: John Wiley & Sons, inc. pp. 140–143. ISBN 0-471-33230-5.
+Haber, Fritz (1920). The Synthesis of Ammonia From its Elements (PDF). Oslo, Sweden: Nobel Foundation. p. 15.
+Hager, Thomas (2008). The Alchemy of Air: A Jewish Genius, a Doomed Tycoon, and the Scientific Discovery That Fed the World but Fueled the Rise of Hitler. New York: Harmony Books. p. 336. ISBN 978-0-307-35178-4.
+Hayes, Peter (2001). Industry and Ideology : IG Farben in the nazi era. New York: Cambridge University Press (published 1971). ISBN 978-0-521-78638-6.
+Jeffreys, Diarmuid (2008). Hell's Cartel: IG Farben and the Making of Hitler's War Machine. Metropolitan Books. p. 496. ISBN 978-0805078138.
+Jones, K.; Bailar, J. C.; Emeléus, H. J.; Nyholm, Sir Ronald Sydney; Trotman-Dickenson, A. F. (1973). Nitrogen. Vol. Comprehensive Inorganic Chemistry. New York: Pergamon Press. p. 547. ISBN 0-08-017275-X.
+Lawrence, Stephen A. (2006). "An Introduction to the Amines". Amines. Synthesis, Properties and Applications. Cambridge University Press. p. 384. ISBN 978-0521029728.
+Maxwell, Gary R. (2004). Synthetic Nitrogen Products: A Practical Guide to the Products and Processes. Springer. p. 388. ISBN 978-0306482250.
+Smil, Vaclav (2001). Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production. MIT Press. p. 358. ISBN 978-0-262-69313-4.
+Travis, Tony (August 1993). "The Haber-Bosch process: exemplar of 20th century chemical industry". Entrepreneur (2). Society of Chemical Industry.
+Travis, Anthony S.; Schröter, Harm G.; Homburg, Ernst; Morris, Peter J. T. (1998). Determinants in the Evolution of the European Chemical Industry, 1900-1939: New Technologies, Political Frameworks, Markets and Companies (Chemists and Chemistry). Springer. p. 300. ISBN 978-0792348900.
+Wiley-VCH (2007). Ullmann's Agrochemicals. United States: Wiley-VCH. p. 932. ISBN 978-3527316045.
+Wisniak, Jaime (2002). "Fritz Haber - a Conflicting Chemist". Proceedings of the Indian National Science Academy. 37 (2): 153–173. ISSN 0019-5235.

data/en.wikipedia.org/wiki/History_of_the_periodic_table-0.md

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+---
+title: "History of the periodic table"
+chunk: 1/10
+source: "https://en.wikipedia.org/wiki/History_of_the_periodic_table"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:27.487948+00:00"
+instance: "kb-cron"
+---
+
+The periodic table is an arrangement of the chemical elements, structured by their atomic number, electron configuration and recurring chemical properties. In the basic form, elements are presented in order of increasing atomic number, in the reading sequence. Then, rows and columns are created by starting new rows and inserting blank cells, so that rows (periods) and columns (groups) show elements with recurring properties (called periodicity). For example, all elements in group (column) 18 are noble gases that are largely—though not completely—unreactive.
+The history of the periodic table reflects over two centuries of growth in the understanding of the chemical and physical properties of the elements, with major contributions made by Antoine-Laurent de Lavoisier, Johann Wolfgang Döbereiner, John Newlands, Julius Lothar Meyer, Dmitri Mendeleev, Glenn T. Seaborg, and others.
+
+== Early history ==
+
+In the 5th century BCE, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles which they called "atoms". Atoms, Democritus believed, are too small to be detected by the senses; they are infinite in numbers and come in infinitely many varieties, and they have existed forever and that these atoms are in constant motion in the void or vacuum. What we perceive as water, fire, plants, or humans are merely combinations of atoms in the void.
+Around 330 BCE, the Greek philosopher Aristotle proposed that everything is made up of a mixture of one or more roots, an idea originally suggested by the Sicilian philosopher Empedocles. The four roots, which the Athenian philosopher Plato called elements, were earth, water, air and fire. Similar ideas existed in other ancient traditions, such as Indian philosophy with five elements: Earth, water, fire, air and aether collectively called 'pañca bhūta'. 
+Of the chemical elements shown on the periodic table, nine – carbon, sulfur, iron, copper, silver, tin, gold, mercury, and lead – have been known since antiquity, as they are found in their native form and are relatively simple to mine with primitive tools. Five more elements were known in the age of alchemy: zinc, arsenic, antimony, and bismuth. Platinum was known to pre-Columbian South Americans, but knowledge of it did not reach Europe until the 16th century.
+
+== First classification ==
+
+The history of the periodic table is also a history of the discovery of the chemical elements. 
+In 1661, Boyle defined elements as "those primitive and simple Bodies of which the mixt ones are said to be composed, and into which they are ultimately resolved."
+The first person in recorded history to discover a new element was Hennig Brand, a bankrupt German merchant. Brand tried to discover the philosopher's stone—a mythical object that was supposed to turn inexpensive base metals into gold. In 1669, or later, his experiments with distilled human urine resulted in the production of a glowing white substance, which he called "cold fire" (kaltes Feuer). He kept his discovery secret until 1680, when Anglo-Irish chemist Robert Boyle rediscovered phosphorus and published his findings.
+The discovery of phosphorus helped to raise the question of what it meant for a substance (any given variety of matter) to be an element, in a world where versions of atomic theory were only speculative and later understandings of the nature of substances were only beginning to become possible.
+In 1718, Étienne François Geoffroy's Affinity Table made use of several aspects — (1) tabular grouping and (2) correlation with chemical affinity — that would later be reprised. 
+
+In 1789, French chemist Antoine Lavoisier wrote Traité Élémentaire de Chimie (Elementary Treatise of Chemistry), which is considered to be the first modern textbook about chemistry. Lavoisier defined an element as a substance whose smallest units cannot be broken down into a simpler substance. Lavoisier's book contained a list of "simple substances" that Lavoisier believed could not be broken down further, which included oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc and sulfur, which formed the basis for the modern list of elements. Lavoisier's list also included "light" and "caloric", which at the time were believed to be material substances. He classified these substances into metals and nonmetals. While many leading chemists refused to believe Lavoisier's new revelations, the Elementary Treatise was written well enough to convince the younger generation. However, Lavoisier's descriptions of his elements lack completeness, as he only classified them as metals and non-metals.
+
+In 1808–10, British natural philosopher John Dalton published a method by which to arrive at provisional atomic weights for the elements known in his day, from stoichiometric measurements and reasonable inferences. Dalton's atomic theory was adopted by many chemists during the 1810s and 1820s.
+In 1815, British physician and chemist William Prout noticed that atomic weights seemed to be multiples of that of hydrogen.
+In 1817, German physicist Johann Wolfgang Döbereiner began to formulate one of the earliest attempts to classify the elements. In 1829, he found that he could form some of the elements into groups of three, with the members of each group having related properties. He termed these groups triads. In 1843, building on work done by Döbereiner, Leopold Gmelin developed a forerunner of the modern periodic table that listed 55 chemical elements grouped by common characteristics.
+Definition of Triad law
+"Chemically analogous elements arranged in increasing order of their atomic weights formed well marked groups of three called Triads in which the atomic weight of the middle element was found to be generally the arithmetic mean of the atomic weight of the other two elements in the triad.

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+---
+title: "History of the periodic table"
+chunk: 2/10
+source: "https://en.wikipedia.org/wiki/History_of_the_periodic_table"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:27.487948+00:00"
+instance: "kb-cron"
+---
+
+chlorine, bromine, and iodine
+calcium, strontium, and barium
+sulfur, selenium, and tellurium
+lithium, sodium, and potassium
+All those attempts to sort elements by atomic weights were inhibited by the inaccurate determination of weights, and not just slightly: carbon, oxygen and many other elements were believed to be half their actual masses (cf. the illustration by Dalton above), because only monatomic gases were believed to exist. Even though Amedeo Avogadro and, independently of him, André-Marie Ampère, proposed the solution in the form of diatomic molecules and Avogadro's law already in the 1810s, it was not until after Stanislao Cannizzaro's publications in late 1850s when the theory began to be widely considered.
+In 1860, the modern scientific consensus emerged at the first international chemical conference, the Karlsruhe Congress, and a revised list of elements and atomic masses was adopted. It helped spur creation of more extensive systems. The first such system emerged in two years.
+
+== Comprehensive formalizations ==
+Properties of the elements, and thus properties of light and heavy bodies formed by them, are in a periodic dependence on their atomic weight.
+French geologist Alexandre-Émile Béguyer de Chancourtois noticed that the elements, when ordered by their atomic weights, displayed similar properties at regular intervals. In 1862, he devised a three-dimensional chart, named the "telluric helix", after the element tellurium, which fell near the center of his diagram. With the elements arranged in a spiral on a cylinder by order of increasing atomic weight, de Chancourtois saw that elements with similar properties lined up vertically. The original paper from Chancourtois in Comptes rendus de l'Académie des Sciences did not include a chart and used geological rather than chemical terms. In 1863, he extended his work by including a chart and adding ions and compounds.
+The next attempt was made in 1864. British chemist John Newlands presented in Chemical News a classification of the 62 known elements. Newlands noticed recurring trends in physical properties of the elements at recurring intervals of multiples of eight in order of mass number; based on this observation, he produced a classification of these elements into eight groups. Each group displayed a similar progression; Newlands likened these progressions to the progression of notes within a musical scale. Newlands's table left no gaps for possible future elements, and in some cases had two elements at the same position in the same octave. Newlands's table was ignored or ridiculed by some of his contemporaries. The Chemical Society refused to publish his work. The president of the Society, William Odling, defended the Society's decision by saying that such "theoretical" topics might be controversial; there was even harsher opposition from within the Society, suggesting the elements could have been just as well listed alphabetically. Later that year, Odling suggested a table of his own but failed to get recognition following his role in opposing Newlands's table.
+German chemist Lothar Meyer also noted the sequences of similar chemical and physical properties repeated at periodic intervals. According to him, if the atomic weights were plotted as ordinates (i.e. vertically) and the atomic volumes as abscissas (i.e. horizontally)—the curve obtained  is a series of maximums and minimums—the most electropositive elements would appear at the peaks of the curve in the order of their atomic weights. In 1864, a book of his was published; it contained an early version of the periodic table containing 28 elements, and classified elements into six families by their valence—for the first time, elements had been grouped according to their valence. Works on organizing the elements by atomic weight had until then been stymied by inaccurate measurements of the atomic weights. In 1868, he revised his table, but this revision was published as a draft only after his death. In a paper dated December 1869 which appeared early in 1870, Meyer published a new periodic table of 55 elements, in which the series of periods are ended by an element of the alkaline earth metal group. The paper also included a line chart of relative atomic volumes, which illustrated periodic relationships of physical characteristics of the elements, and which assisted Meyer in deciding where elements should appear in his periodic table. By this time he had already seen the publication of Mendeleev's first periodic table, but his work appears to have been largely independent.
+In 1869, Russian chemist Dmitri Mendeleev arranged 63 elements by increasing atomic weight in several columns, noting recurring chemical properties across them. It is sometimes said that he played "chemical solitaire" on long train journeys, using cards containing the symbols, atomic weights, and chemical properties of the known elements. Another possibility is that he was inspired in part by the periodicity of the Sanskrit alphabet, which was pointed out to him by his friend and linguist Otto von Böhtlingk. Mendeleev used the trends he saw to suggest that atomic weights of some elements were incorrect, and accordingly changed their placements: for instance, he figured there was no place for a trivalent beryllium with the atomic weight of 14 in his work, and he cut both the atomic weight and valency of beryllium by a third, suggesting it was a divalent element with the atomic weight of 9.4. Mendeleev widely distributed printed broadsheets of the table to various chemists in Russia and abroad. Mendeleev argued in 1869 there were seven types of highest oxides. Mendeleev continued to improve his ordering; in 1870, it gained a tabular shape, and each column was given its own highest oxide, and in 1871, he further developed it and formulated what he termed the "law of periodicity". Some changes also occurred with new revisions, with some elements changing positions.

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+---
+title: "History of the periodic table"
+chunk: 3/10
+source: "https://en.wikipedia.org/wiki/History_of_the_periodic_table"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:27.487948+00:00"
+instance: "kb-cron"
+---
+
+== Priority dispute and recognition ==
+In 1881, Mendeleev claimed priority over Meyer for the periodic table as follows:That person is rightly regarded as the creator of a particular scientific idea who perceives not merely its philosophical, but its real aspect, and who understands so to illustrate the matter so that everyone can become convinced of its truth. Then alone the idea, like matter, becomes indestructible.
+
+=== Mendeleev's predictions and inability to incorporate the rare-earth metals ===
+
+Even as Mendeleev corrected positions of some elements, he thought that some relationships that he could find in his grand scheme of periodicity could not be found because some elements were still undiscovered, and that the properties of such undiscovered elements could be deduced from their expected relationships with other elements. In 1870, he first tried to characterize the yet undiscovered elements, and he gave detailed predictions for three elements, which he termed eka-boron, eka-aluminium, and eka-silicium; he also more briefly noted a few other expectations. It has been proposed that the prefixes eka, dvi, and tri, Sanskrit for one, two, and three, respectively, are a tribute to Pāṇini and other ancient Sanskrit grammarians for their invention of a periodic alphabet. In 1871, Mendeleev expanded his predictions further.
+Compared to the rest of the work, Mendeleev's 1869 list misplaces seven then known elements: indium, thorium, and five rare-earth metals: yttrium, cerium, lanthanum, erbium, and didymium. The last two were later found to be mixtures of two different elements; ignoring those would allow him to restore the logic of increasing atomic weight. These elements (all thought to be divalent at the time) puzzled Mendeleev as they did not show a regular increase in valency despite their seemingly consequential atomic weights. Mendeleev grouped them together, thinking of them as of a particular kind of series. In early 1870, he decided that the weights for these elements must be wrong and that the rare-earth metals should be trivalent (which accordingly increased their predicted atomic weights by half). He measured the heat capacity of indium, uranium, and cerium to demonstrate their higher assumed valency (which was soon confirmed by Prussian chemist Robert Bunsen). Mendeleev treated the change by assessing each element to an individual place in his system of the elements rather than continuing to treat them as a series.
+Mendeleev noticed that there was a significant difference in atomic mass between cerium and tantalum with no element between them; his consideration was that between them, there was a row of yet undiscovered elements, which would display similar properties to those elements which were to be found above and below them: for instance, an eka-molybdenum would behave as a heavier homolog of molybdenum and a lighter homolog of wolfram (the name under which Mendeleev knew tungsten). This row would begin with a trivalent lanthanum, a tetravalent cerium, and a pentavalent didymium. However, the higher valency for didymium had not been established, and Mendeleev tried to do so himself. Having had no success in that, he abandoned his attempts to incorporate the rare-earth metals in late 1871 and embarked on his grand idea of luminiferous ether. His idea was carried on by Austrian-Hungarian chemist Bohuslav Brauner, who sought to find a place in the periodic table for the rare-earth metals; Mendeleev later referred to him as to "one of the true consolidators of the periodic law".
+In addition to the predictions of scandium, gallium, and germanium that were quickly realized, Mendeleev's 1871 table left many more spaces for undiscovered elements, though he did not provide detailed predictions of their properties. In total, he predicted eighteen elements, though only half corresponded to elements that were later discovered.
+
+=== Priority of discovery ===
+None of the proposals were accepted immediately, and many contemporary chemists found it too abstract to have any meaningful value. Of those chemists that proposed their categorizations, Mendeleev strove to back his work and promote his vision of periodicity, Meyer did not promote his work very actively, and Newlands did not make a single attempt to gain recognition abroad.
+Both Mendeleev and Meyer created their respective tables for their pedagogical needs; the difference between their tables is well explained by the fact that the two chemists sought to use a formalized system to solve different problems. Mendeleev's intent was to aid composition of his textbook, Foundations of Chemistry, whereas Meyer was rather concerned with presentation of theories. Mendeleev's predictions emerged outside of the pedagogical scope in the realm of journal science, while Meyer made no predictions at all and explicitly stated his table and his textbook it was contained in, Modern Theories, should not be used for prediction in order to make the point to his students to not make too many purely theoretically constructed projections.
+Mendeleev and Meyer differed in temperament, at least when it came to promotion of their respective works. Boldness of Mendeleev's predictions was noted by some contemporary chemists, however skeptical they may have been. Meyer referred to Mendeleev's "boldness" in an edition of Modern Theories, whereas Mendeleev mocked Meyer's indecisiveness to predict in an edition of Foundations of Chemistry.
+
+=== Recognition of Mendeleev's table ===
+Eventually, the periodic table was appreciated for its descriptive power and for finally systematizing the relationship between the elements, although such appreciation was not universal. In 1881, Mendeleev and Meyer had an argument via an exchange of articles in British journal Chemical News over priority of the periodic table, which included an article from Mendeleev, one from Meyer, one of critique of the notion of periodicity, and many more. In 1882, the Royal Society in London awarded the Davy Medal to both Mendeleev and Meyer for their work to classify the elements; although two of Mendeleev's predicted elements had been discovered by then, Mendeleev's predictions were not at all mentioned in the prize rationale.

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+---
+title: "History of the periodic table"
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+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:27.487948+00:00"
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+---
+
+Mendeleev's eka-aluminium was discovered in 1875 and became known as gallium; eka-boron and eka-silicium were discovered in 1879 and 1886, respectively, and were named scandium and germanium. Mendeleev was even able to correct some initial measurements with his predictions, including the first prediction of gallium, which matched eka-aluminium fairly closely but had a different density. Mendeleev advised the discoverer, French chemist Paul-Émile Lecoq de Boisbaudran, to measure the density again; de Boisbaudran was initially skeptical (not least because he thought Mendeleev was trying to take credit from him) but eventually admitted the correctness of the prediction. Mendeleev contacted all three discoverers; all three noted the close similarity of their discovered elements with Mendeleev's predictions, with the last of them, German chemist Clemens Winkler, admitting this suggestion was not first made by Mendeleev or himself after the correspondence with him, but by a different person, German chemist Hieronymous Theodor Richter. Some contemporary chemists were not convinced by these discoveries, noting the dissimilarities between the new elements and the predictions or claiming those similarities that did exist were coincidental. However, success of Mendeleev's predictions helped spread the word about his periodic table. Later, chemists used the successes of these Mendeleev's predictions to justify his table.
+By 1890, Mendeleev's periodic table had been universally recognized as a piece of basic chemical knowledge. Apart from his own correct predictions, a number of aspects may have contributed to this, such as the correct accommodation of many elements whose atomic weights were thought to have wrong values but were later corrected. The debate on the position of the rare-earth metals helped spur the discussion about the table as well. In 1889, Mendeleev noted at the Faraday Lecture to the Royal Institution in London that he had not expected to live long enough "to mention their discovery to the Chemical Society of Great Britain as a confirmation of the exactitude and generality of the periodic law".
+
+== Inert gases and ether ==
+The great value of Newland's, Mendeleef's, and Lothar Meyer's generalisation, known as the periodic arrangement of the elements, is universally acknowledged. But a study of this arrangement, it must be allowed, is a somewhat tantalising pleasure; for, although the properties of elements do undoubtedly vary qualitatively, and, indeed, show approximate quantitative relations to their position in the periodic table, yet there are inexplicable deviations from regularity, which hold forth hopes of the discovery of a still more far-reaching generalisation. What that generalisation may be is not yet to be divined; but that it must underlie what is known, and must furnish a clue to the explanation of irregularities, cannot be disputed. 

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+title: "History of the periodic table"
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+---
+
+=== Inert gases ===
+British chemist Henry Cavendish, the discoverer of hydrogen in 1766, discovered that air is composed of more gases than nitrogen and oxygen. He recorded these findings in 1784 and 1785; among them, he found a then-unidentified gas less reactive than nitrogen. Helium was first reported in 1868; the report was based on the new technique of spectroscopy; some spectral lines in light emitted by the Sun did not match those of any of the known elements. Mendeleev was not convinced by this finding since variance of temperature led to change of intensity of spectral lines and their location on the spectrum. This opinion was held by some other scientists of the day, some of whom believed the spectral lines were due to a particular state of hydrogen existing in the Sun's atmosphere. Others believed the spectral lines could belong to an element that occurred on the Sun but not on Earth; some believed it was yet to be found on Earth.
+In 1894, British chemist William Ramsay and British physicist Lord Rayleigh isolated argon from air and determined that it was a new element. Argon, however, did not engage in any chemical reactions and was—highly unusually for a gas—monatomic; it did not fit into the periodic law and thus challenged the very notion of it. Not all scientists immediately accepted this report; Mendeleev's original response was that argon was a triatomic form of nitrogen rather than an element of its own. While the notion of a possibility of a group between that of halogens and that of alkali metals had existed (some scientists believed that several atomic weight values between halogens and alkali metals were missing, especially since places in this half of group VIII remained vacant), argon did not easily match the position between chlorine and potassium because its atomic weight exceeded those of both chlorine and potassium. Other explanations were proposed; for example, Ramsay supposed argon could be a mixture of different gases. For a while, Ramsay believed argon could be a mixture of three gases of similar atomic weights; this triad would resemble the triad of iron, cobalt, and nickel, and be similarly placed in group VIII. Certain that shorter periods contain triads of gases at their ends, Ramsay suggested in 1898 the existence of a gas between helium and argon with an atomic weight of 20; after its discovery later that year (it was named neon), Ramsay continued to interpret it as a member of a horizontal triad at the end of that period.
+In 1896, Ramsay tested a report of American chemist William Francis Hillebrand, who found a stream of an unreactive gas from a sample of uraninite. Wishing to prove it was nitrogen, Ramsay analyzed a different uranium mineral, cleveite, and found a new element, which he named krypton. This finding was corrected by British chemist William Crookes, who matched its spectrum to that of the Sun's helium. Following this discovery, Ramsay, using fractional distillation to separate the components air, discovered several more such gases in 1898: metargon, krypton, neon, and xenon; detailed spectroscopic analysis of the first of these demonstrated it was argon contaminated by a carbon-based impurity. Ramsay was initially skeptical about the existence of gases heavier than argon, and the discovery of krypton and xenon came as a surprise to him; however, Ramsay accepted his own discovery, and the five newly discovered inert gases (now noble gases) were placed in a single column in the periodic table. Although Mendeleev's table predicted several undiscovered elements, it did not predict the existence of such inert gases, and Mendeleev originally rejected those findings as well.

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+title: "History of the periodic table"
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+---
+
+=== Changes to the periodic table ===
+Although the sequence of atomic weights suggested that inert gases should be located between halogens and alkali metals, and there were suggestions to put them into group VIII coming from as early as 1895, such placement contradicted one of Mendeleev's basic considerations, that of the highest oxides. Inert gases did not form any oxides, and no other compounds at all, and as such, their placement in a group where elements should form tetroxides was seen as merely auxiliary and not natural; Mendeleev doubted inclusion of those elements in group VIII. Later developments, particularly by British scientists, focused on correspondence of inert gases with halogens to their left and alkali metals to their right. In 1898, when only helium, argon, and krypton were definitively known, Crookes suggested these elements be placed in a single column between the hydrogen group and the fluorine group. In 1900, at the Prussian Academy of Sciences, Ramsay and Mendeleev discussed the new inert gases and their location in the periodic table; Ramsay proposed that these elements be put in a new group between halogens and alkali metals, to which Mendeleev agreed. Ramsay published an article after his discussions with Mendeleev; the tables in it featured halogens to the left of inert gases and alkali metals to the right. Two weeks before that discussion, Belgian botanist Léo Errera had proposed to the Royal Academy of Science, Letters and Fine Arts of Belgium to put those elements in a new group 0. In 1902, Mendeleev wrote that those elements should be put in a new group 0; he said this idea was consistent with what Ramsay suggested to him and referred to Errera as to the first person to suggest the idea. Mendeleev himself added these elements to the table as group 0 in 1902, without disturbing the basic concept of the periodic table.
+In 1905, Swiss chemist Alfred Werner resolved the dead zone of Mendeleev's table. He determined that the rare-earth elements (lanthanides), 13 of which were known, lay within that gap. Although Mendeleev knew of lanthanum, cerium, and erbium, they were previously unaccounted for in the table because their total number and exact order were not known; Mendeleev still could not fit them in his table by 1901. This was in part a consequence of their similar chemistry and the imprecise determination of their atomic masses. Combined with the lack of a known group of similar elements, this rendered the placement of the lanthanides in the periodic table difficult. This discovery led to a restructuring of the table and the first appearance of the 32-column form.
+
+=== Ether ===
+By 1904, Mendeleev's table rearranged several elements, and included the noble gases along with most other newly discovered elements. It still had the dead zone, and a row zero was added above hydrogen and helium to include coronium and the ether, which were widely believed to be elements at the time. Although the Michelson–Morley experiment in 1887 cast doubt on the possibility of a luminiferous ether as a space-filling medium, physicists set constraints for its properties. Mendeleev believed it to be a very light gas, with an atomic weight several orders of magnitude smaller than that of hydrogen. He also postulated that it would rarely interact with other elements, similar to the noble gases of his group zero, and instead permeate substances at a velocity of 2,250 kilometers (1,400 mi) per second.
+Mendeleev was not satisfied with the lack of understanding of the nature of this periodicity; this would only be possible through the understanding of the composition of the atom. However, Mendeleev firmly believed that future would only develop the notion rather than challenge it and reaffirmed his belief in writing in 1902.
+
+== Atomic theory and isotopes ==
+
+=== Radioactivity and isotopes ===

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+
+In 1907 it was discovered that thorium and radiothorium, products of radioactive decay, were physically different but chemically identical; this led Frederick Soddy to propose in 1910 that they were the same element but with different atomic weights. Soddy later proposed to call these elements with complete chemical identity "isotopes".
+The problem of placing isotopes in the periodic table had arisen beginning in 1900 when four radioactive elements were known: radium, actinium, thorium, and uranium. These radioactive elements (termed "radioelements") were accordingly placed at the bottom of the periodic table, as they were known to have greater atomic weights than stable elements, although their exact order was not known. Researchers believed there were still more radioactive elements yet to be discovered, and during the next decade, the decay chains of thorium and uranium were extensively studied. Many new radioactive substances were found, including the noble gas radon, and their chemical properties were investigated. By 1912, almost 50 different radioactive substances had been found in the decay chains of thorium and uranium. American chemist Bertram Boltwood proposed several decay chains linking these radioelements between uranium and lead. These were thought at the time to be new chemical elements, substantially increasing the number of known "elements" and leading to speculations that their discoveries would undermine the concept of the periodic table which had long been established to obey the octet rule. For example, there was not enough room between lead and uranium to accommodate these discoveries, even assuming that some discoveries were duplicates or incorrect identifications. It was also believed that radioactive decay violated one of the central principles of the periodic table, namely that chemical elements could not undergo transmutations and always had unique identities.
+Soddy and Kazimierz Fajans, who had been following these developments, published in 1913 that although these substances emitted different radiation, many of these substances were identical in their chemical characteristics, so shared the same place in the periodic table. They became known as isotopes, from the Greek isos topos ("same place"). Austrian chemist Friedrich Paneth cited a difference between "real elements" (elements) and "simple substances" (isotopes), also determining that the existence of different isotopes was mostly irrelevant in determining chemical properties.
+Following British physicist Charles Glover Barkla's discovery of characteristic X-rays emitted from metals in 1906, British physicist Henry Moseley considered a possible correlation between X-ray emissions and physical properties of elements. Moseley, along with Charles Galton Darwin, Niels Bohr, and George de Hevesy, proposed that the nuclear charge (Z) might be mathematically related to physical properties. The significance of these atomic properties was determined in the Geiger–Marsden experiments, in which the atomic nucleus and its charge were discovered, conducted between 1908 and 1913.
+
+=== Rutherford model and atomic number ===
+
+In 1913, amateur Dutch physicist Antonius van den Broek was the first to propose that the atomic number (nuclear charge) determined the placement of elements in the periodic table. He correctly determined the atomic number of all elements up to atomic number 50 (tin), though he made several errors with heavier elements. However, Van den Broek did not have any method to experimentally verify the atomic numbers of elements; thus, they were still believed to be a consequence of atomic weight, which remained in use in ordering elements.
+Moseley was determined to test Van den Broek's hypothesis. After a year of investigation of the characteristic x-rays of various elements, he found a relationship between the X-ray wavelength of an element and its atomic number. With this, Moseley obtained the first accurate measurements of atomic numbers and determined an absolute sequence to the elements, allowing him to restructure the periodic table. Moseley's research immediately resolved discrepancies between atomic weight and chemical properties, where sequencing strictly by atomic weight would result in groups with inconsistent chemical properties. For example, his measurements of X-ray wavelengths enabled him to correctly place argon (Z = 18) before potassium (Z = 19), cobalt (Z = 27) before nickel (Z = 28), as well as tellurium (Z = 52) before iodine (Z = 53), in line with periodic trends. The determination of atomic numbers also clarified the order of chemically similar rare-earth elements; it was also used to confirm that Georges Urbain's claimed discovery of a new rare-earth element (celtium) was invalid, earning Moseley acclamation for this technique.
+Swedish physicist Karl Siegbahn continued Moseley's work for elements heavier than gold (Z = 79), and found that the heaviest known element at the time, uranium, had atomic number 92. In determining the largest identified atomic number, gaps in the atomic number sequence were conclusively determined where an atomic number had no known corresponding element; the gaps occurred at atomic numbers 43 (technetium), 61 (promethium), 72 (hafnium), 75 (rhenium), 85 (astatine), and 87 (francium).

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+title: "History of the periodic table"
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+---
+
+=== Electron shell and quantum mechanics ===
+In 1914, Swedish physicist Johannes Rydberg noticed that the atomic numbers of the noble gases was equal to doubled sums of squares of simple numbers: 2 = 2·12, 10 = 2(12 + 22), 18 = 2(12 + 22 + 22), 36 = 2(12 + 22 + 22 + 32), 54 = 2(12 + 22 + 22 + 32 + 32), 86 = 2(12 + 22 + 22 + 32 + 32 + 42). This finding was accepted as an explanation of the fixed lengths of periods and eventually paved the way to repositioning of the noble gases from the left edge of the table, in group 0, to the right, in group VIII. Unwillingness of the noble gases to engage in chemical reaction was explained in the alluded stability of closed noble gas electron configurations; from this notion emerged the octet rule originally referred to as Abegg's Rule of 1904. Among the notable works that established the importance of the periodicity of eight were the valence bond theory, published in 1916 by American chemist Gilbert N. Lewis and the octet theory of chemical bonding, published in 1919 by American chemist Irving Langmuir. The chemists' approach during the period of the Old Quantum Theory (1913 to 1925) was incorporated into the understanding of the electron shells and orbitals under current quantum mechanics. In his 1919 paper, Langmuir postulated the existence of "cells", which we now call atomic orbitals, and these were arranged in "equidistant layers" which we now call electron shells. These postulates were introduced on the basis of Rydberg's rule which Niels Bohr had used not in chemistry, but in physics, to apply to the orbits of electrons around the nucleus. The Langmuir paper introduced the rule as 2N2 where N was a positive integer.
+British chemist Charles Rugeley Bury made the next major step toward the modern theory in 1921, by suggesting that eight and eighteen electrons in a shell form stable configurations. Bury's scheme was built upon that of earlier chemists and was a chemical model. Bury proposed that the electron configurations in transitional elements depended upon the valency electrons in their outer shell. In some early papers, the model was called the "Bohr-Bury Atom". He introduced the word transition to describe the elements now known as transition metals or transition elements.
+In the 1910s and 1920s, pioneering research into quantum mechanics led to new developments in atomic theory and small changes to the periodic table. In the 19th century, Mendeleev had already asserted that there was a fixed periodicity of eight, and expected a mathematical correlation between atomic number and chemical properties. The Bohr model was developed beginning 1913, and championed the idea of electron configurations that determine chemical properties. Bohr proposed that elements in the same group behaved similarly because they have similar electron configurations, and that noble gases had filled valence shells; this forms the basis of the modern octet rule. Bohr's study of spectroscopy and chemistry was not usual among theoretical atomic physicists. Even Rutherford told Bohr that he was struggling "to form an idea of how you arrive at your conclusions". This is because none of the quantum mechanical equations describe the number of electrons per shell and orbital. Bohr acknowledged that he was influenced by the work of Walther Kossel, who in 1916 was the first to establish an important connection between the quantum atom and the periodic table. He noticed that the difference between the atomic numbers 2, 10, 18 of the first three noble gases, helium, neon, argon, was 8, and argued that the electrons in such atoms orbited in "closed shells". The first contained only 2 electrons, the second and third, 8 each. Bohr's research then led Austrian physicist Wolfgang Pauli to investigate the length of periods in the periodic table in 1924. Pauli demonstrated that this was not the case. Instead, the Pauli exclusion principle was developed, not upon a mathematical basis, but upon the previous developments in alignment with chemistry. This rule states that no electrons can coexist in the same quantum state, and showed, in conjunction with empirical observations, the existence of four quantum numbers and the consequence on the order of shell filling. This determines the order in which electron shells are filled and explains the periodicity of the periodic table.
+British chemist Charles Bury is credited with the first use of the term transition metal in 1921 to refer to elements between the main-group elements of groups II and III. He explained the chemical properties of transition elements as a consequence of the filling of an inner subshell rather than the valence shell. This proposition, based upon the work of American chemist Gilbert N. Lewis, suggested the appearance of the d subshell in period 4 and the f subshell in period 6, lengthening the periods from 8 to 18 and then 18 to 32 elements, thus explaining the position of the lanthanides in the periodic table.
+
+=== Proton and neutron ===
+
+The discovery of proton and neutron demonstrated that an atom was divisible; this rendered Lavoisier's definition of a chemical element obsolete. A chemical element is defined today as a species of atoms with a consistent number of protons and that number is now known to be precisely the atomic number of an element. The discovery also explained the mechanism of several types of radioactive decay, such as alpha decay.
+Eventually, it was proposed that protons and neutrons were made of even smaller particles called quarks; their discovery explained the transmutation of neutrons into protons in beta decay.
+
+== From short form into long form (into -A and -B groups) ==

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+title: "History of the periodic table"
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+
+Circa 1925, the periodic table changed by shifting some Reihen (series) to the right, into an extra set of columns (groups). The original groups I–VII were repeated, distinguished by adding "A" and "B". Group VIII (with three columns) remained sole.
+Thus, Reihen 4 and 5 were shifted, and together formed new period 4 with groups IA–VIIA, VIII, IB–VIIB.
+
+== Later expansions and the end of the periodic table ==
+We already feel that we have neared the moment when this [periodic] law begins to change, and change fast.
+
+=== Actinides ===
+As early as 1913, Bohr's research on electronic structure led physicists such as Johannes Rydberg to extrapolate the properties of undiscovered elements heavier than uranium. Many agreed that the next noble gas after radon would most likely have the atomic number 118, from which it followed that the transition series in the seventh period should resemble those in the sixth. Although it was thought that these transition series would include a series analogous to the rare-earth elements, characterized by filling of the 5f shell, it was unknown where this series began. Predictions ranged from atomic number 90 (thorium) to 99, many of which proposed a beginning beyond the known elements (at or beyond atomic number 93). The elements from actinium to uranium were instead believed to form part of a fourth series of transition metals because of their high oxidation states; accordingly, they were placed in groups 3 through 6.
+In 1940, neptunium and plutonium were the first transuranic elements to be discovered; they were placed in sequence beneath rhenium and osmium, respectively. However, preliminary investigations of their chemistry suggested a greater similarity to uranium than to lighter transition metals, challenging their placement in the periodic table. During his Manhattan Project research in 1943, American chemist Glenn T. Seaborg experienced unexpected difficulties in isolating the elements americium and curium, as they were believed to be part of a fourth series of transition metals. Seaborg wondered if these elements belonged to a different series, which would explain why their chemical properties, in particular the instability of higher oxidation states, were different from predictions. In 1945, against the advice of colleagues, he proposed a significant change to Mendeleev's table: the actinide series.
+Seaborg's actinide concept of heavy element electronic structure proposed that the actinides form an inner transition series analogous to the rare-earth series of lanthanide elements—they would comprise the second row of the f-block (the 5f series), in which the lanthanides formed the 4f series. This facilitated chemical identification of americium and curium, and further experiments corroborated Seaborg's hypothesis; a spectroscopic study at the Los Alamos National Laboratory by a group led by American physicist Edwin McMillan indicated that 5f orbitals, rather than 6d orbitals, were indeed being filled. However, these studies could not unambiguously determine the first element with 5f electrons and therefore the first element in the actinide series; it was thus also referred to as the "thoride" or "uranide" series until it was later found that the series began with actinium.
+In light of these observations and an apparent explanation for the chemistry of transuranic elements, and despite fear among his colleagues that it was a radical idea that would ruin his reputation, Seaborg nevertheless submitted it to Chemical & Engineering News and it gained widespread acceptance; new periodic tables thus placed the actinides below the lanthanides. Following its acceptance, the actinide concept proved pivotal in the groundwork for discoveries of heavier elements, such as berkelium in 1949. It also supported experimental results for a trend towards +3 oxidation states in the elements beyond americium—a trend observed in the analogous 4f series.
+
+=== Relativistic effects and breakdown of the periodic law in period 7 ===
+
+=== Expansions beyond period 7 ===
+Seaborg's subsequent elaborations of the actinide concept theorized a series of superheavy elements in a transactinide series comprising elements from 104 to 121 and a superactinide series of elements from 122 to 153. He proposed an extended periodic table with an additional period of 50 elements (thus reaching element 168); this eighth period was derived from an extrapolation of the Aufbau principle and placed elements 121 to 138 in a g-block, in which a new g subshell would be filled. Seaborg's model, however, did not take into account relativistic effects resulting from high atomic number and electron orbital speed. Burkhard Fricke in 1971 and Pekka Pyykkö in 2010 used computer modeling to calculate the positions of elements up to Z = 172, and found that the positions of several elements were different from those predicted by Seaborg. Although models from Pyykkö and Fricke generally place element 172 as the next noble gas, there is no clear consensus on the electron configurations of elements beyond 120 and thus their placement in an extended periodic table. It is now thought that because of relativistic effects, such an extension will feature elements that break the periodicity in known elements, thus posing another hurdle to future periodic table constructs.
+The discovery of tennessine in 2010 filled the last remaining gap in the seventh period. Any newly discovered elements will thus be placed in an eighth period.
+Despite the completion of the seventh period, experimental chemistry of some transactinides has been shown to be inconsistent with the periodic law. In the 1990s, Ken Czerwinski at University of California, Berkeley observed similarities between rutherfordium and plutonium and between dubnium and protactinium, rather than a clear continuation of periodicity in groups 4 and 5. More recent experiments on copernicium and flerovium have yielded inconsistent results, some of which suggest that these elements behave more like the noble gas radon rather than mercury and lead, their respective congeners. As such, the chemistry of many superheavy elements has yet to be well characterized, and it remains unclear whether the periodic law can still be used to extrapolate the properties of undiscovered elements.
+
+== See also ==
+
+== Notes ==
+
+== References ==

data/en.wikipedia.org/wiki/History_of_the_periodic_table-9.md

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+---
+title: "History of the periodic table"
+chunk: 10/10
+source: "https://en.wikipedia.org/wiki/History_of_the_periodic_table"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:27.487948+00:00"
+instance: "kb-cron"
+---
+
+== Sources ==
+Gordin, M. D. (2012). "The Textbook Case of a Priority Dispute: D. I. Mendeleev, Lothar Meyer, and the Periodic System". In Biagioli, M.; Riskin, J. (eds.). Nature Engaged. Palgrave Macmillan. pp. 59–82. doi:10.1057/9780230338029_4. ISBN 978-1-349-28717-8.
+Mendeleev, D. I. (1870). Естественная система элементов и применение ее к указанию свойств неоткрытых элементов [The natural system of the elements and its application to indication of properties of unknown elements]. pp. 102–176.. Republished from Mendeleev, D. I. (1871). "Естественная система элементовъ и примѣненіе её къ указанію свойствъ неоткрытыхъ элементовъ" [The natural system of the elements and its application to indication of properties of unknown elements]. Journal of the Russian Physico-Chemical Society (in Russian). 3 (2): 25–56. Archived from the original on 17 March 2014.
+Mendeleev, D. I. (1871). Периодическая законность химических элементов [Periodic regularity of the chemical elements]. pp. 102–176.. Republished from Mendelejeff, D. (1871). "Die periodische Gesetzmässigkeit der Elemente" [Periodic regularity of the chemical elements]. Annalen der Chemie und Pharmacie (in German). Suppl. 8: 133–229.
+Petrov, L. P. (1981). Прогнозирование и размещение инертных элементов в периодической системе [Forecasting and placing of inert elements in the periodic system] (in Russian).
+Scerri, E. R. (2019). The Periodic Table: Its Story and Its Significance. Oxford University Press. ISBN 978-0-19-091436-3.
+Thyssen, Pieter; Binnemans, Koen (2015). "Mendeleev and the Rare-Earth Crisis". Philosophy of Chemistry (PDF). Boston Studies in the Philosophy and History of Science. Vol. 306. pp. 155–182. doi:10.1007/978-94-017-9364-3_11. ISBN 978-94-017-9363-6.
+
+== Further reading ==
+Mendeleev, D. I. (1902). Попытка химического понимания мирового эфира [Attempt of chemical understanding of the world ether]. pp. 470–517.. Republished from Mendeleev, D. (1905). Попытка химическаго пониманія мірового эѳира [Attempt of chemical understanding of the world ether] (in Russian). M. P. Frolova's typo-lithography. pp. 5–40.
+Mendeleev, D. I. (1958). Kedrov, K. M. (ed.). Периодический закон [The periodic law] (in Russian). Academy of Sciences of the USSR.
+Trifonov, D. I., ed. (1981). Учение о периодичности: история и современность [Teaching of periodicity: history and modernity] (in Russian). Nauka.
+
+== External links ==
+Development of the periodic table (part of a collection of pages that explores the periodic table and the elements) by the Royal Society of Chemistry
+Dr. Eric Scerri's web page, which contains interviews, lectures and articles on various aspects of the periodic system, including the history of the periodic table.
+The Internet Database of Periodic Tables – a large collection of periodic tables and periodic system formulations.
+History of Mendeleev periodic table of elements as a data visualization at Stack Exchange

data/en.wikipedia.org/wiki/Iatrochemistry-0.md

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+---
+title: "Iatrochemistry"
+chunk: 1/4
+source: "https://en.wikipedia.org/wiki/Iatrochemistry"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:28.928632+00:00"
+instance: "kb-cron"
+---
+
+Iatrochemistry (from Ancient Greek  ἰατρός (iatrós) 'physician, medicine'; also known as chemiatria or chemical medicine) is an archaic pre-scientific school of thought that was supplanted by modern chemistry and medicine. Having its roots in alchemy, iatrochemistry sought to provide chemical solutions to diseases and medical ailments.
+This area of science fell out of use in Europe since the rise of modern establishment medicine.  Iatrochemistry was popular between 1525 and 1660, especially in the Low Countries.  Its most notable leader was Paracelsus, an important Swiss alchemist of the 16th century. Iatrochemists believed that physical health was dependent on a specific balance of bodily fluids.  Iatrochemical therapies and concepts are still in wide use in South Asia, East Asia and amongst their diasporic communities worldwide.
+
+== History in Europe ==

data/en.wikipedia.org/wiki/Iatrochemistry-2.md

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+---
+title: "Iatrochemistry"
+chunk: 3/4
+source: "https://en.wikipedia.org/wiki/Iatrochemistry"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:28.928632+00:00"
+instance: "kb-cron"
+---
+
+In continuation of humoral medicine, Sylvius did deem that diseases resulted from excesses of the humors in the body, but he saw it as a more chemically driven excess, specifically one of too much acid or alkali solution in the body. Sylvius had his own laboratory in which he ran experiments on acids and alkali solutions to see the result when different mixtures were made. Much of his theories of the human body were based on the digestive processes. His understanding was that digestion helped food undergo a fermentation reaction. He reasoned that the body functioned mainly as a result of chemical reactions, of which acids and alkali were the essential reactants and were products which needed to be kept in balance to be in a healthy state. Although Sylvius did not take on the more observation-based style of medicine that was being so championed in the 17th and 18th centuries, his emphasis on the chemical reactions and knowledge helped support this more observation-driven scientific approach to medicine. It is known that many of Sylvius' inquiries did help in the future discoveries of certain enzymes driving food digestion and bodily reactions. The understanding of iatrochemists helped to drive new knowledge of how drugs work and treat medical conditions. In particular, one English iatrochemist, Thomas Willis (1621–1675), considered the effect of diaphoretics (sweat-promoting drugs) as resulting from the mechanisms of the drug entering the blood and associating or disturbing blood and flow which produces a state of heat and sweat. He also hypothesized that the working of opiates came from an interaction with a salt in the body that created a painless and woozy feeling when it reached the brain. In his treatise De fermentalione (1659), Willis rejected the four Aristotelian elements of earth, air, fire and water, stating that they provided no special insight into "the more secret recesses of nature". Willis settled on a view on the organization of natural things based strictly on chemistry. Such a view, he wrote, "resolves all Bodies into Particles of Spirit, Sulphur, Salt, Water, and Earth ... Because this Hypothesis determinates Bodies into sensible parts, and cutts open things as it were to the life, it pleases us before the rest." Willis derived many of his conclusions from observations on distillation. It was eventually realized that these explanations were not accurate. Natural philosopher Robert Boyle contributed greatly to the understanding of respiration by showing that air (or oxygen), which is required for fire in combustion reactions, is also needed for human breathing.[1] Despite this, Boyle's works on the mechanical origin of qualities were generally rather remote from Helmontian chemistry; however, Boyle's philosophy and Helmontian iatrochemistry were not mutually exclusive. Like van Helmont, Boyle claimed that spirit of human blood, like other ingredients obtained by the chemical analysis of blood, was no simple substance.

data/en.wikipedia.org/wiki/Iatrochemistry-3.md

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+---
+title: "Iatrochemistry"
+chunk: 4/4
+source: "https://en.wikipedia.org/wiki/Iatrochemistry"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:28.928632+00:00"
+instance: "kb-cron"
+---
+
+=== Challenge to Galenic physiology ===
+
+Iatrochemistry was a new practice in the 17th century, a time when traditional medicines were based on a legacy from the 4th and 5th centuries B.C.  Much of this tradition was derived from Galen and Avicenna.  The iatrochemists rejected the traditional medical theory, mostly from Galenic traditionalists.  Galen traditionalists sought to establish the balance of temperament within the bodies.  There are two pairs of qualities, hot and cold, and wet and dry. Sickness came from the imbalance of one quality.  That is, a cold was an excess of heat (hot quality), so it can be cured by reducing hot quality or by increasing cold quality.  The iatrochemists, influenced by Paracelsus's belief, believed that the sickness was from the outside source, not because of the imbalance of the body.
+Another controversy between Galenic traditionalists and iatrochemists was the way to use herbs.  The Galenic traditionalists thought that the strength of remedies relied on the amount of plant materials that was used.  The iatrochemists, however, supported the chemical preparation of materials of remedies to increase the effectiveness of the materials or to find the stronger medicine.
+Additionally, Galenic traditionalists argued that chemically prepared medicines were poisonous, and the iatrochemists were inadequately trained.  The former was true, and, in some cases, both were correct.  Since Paracelsus claimed that poisons could have beneficial medical effects, the number of toxic ingredients used in chemical medicines had increased.  Galenic traditionalists later adapted medical method and some remedies to use in their own fields.
+
+== History in South Asia ==
+Iatrochemical principles form a major part of the Indian alchemical tradition (Sanskrit rasaśāstra, रसशास्त्र). Alchemical texts start to be composed in Sanskrit in South Asia from the end of the first millennium CE, and a flourishing literature developed and continued even into the twentieth century. These works contain extensive chapters on the use of alchemical recipes for healing.
+The use of plants, minerals and metals in medical therapeutics also existed in India. In Ayurvedic medicine, substances used in these therapeutics were known as 'Rasa dravyas.' Ayurvedic medicine instills the belief that every material had the potential to be used as a substance. This drove the creation of new products and new uses for common substances in nature. The people of Ayurvedic medicine categorize the materials in nature into three categories: 'Janagama,' substances from animals such as milk, urine, blood, and meat, 'Audbhida' or substances from plants such as stems, roots or leaves, and 'Paarthiwa' or metal/mineral substances such as gold, silver, copper or sulfur. There was especially an emphasis on the element, Mercury, in this culture. The name of these specific practices in Ayurvedic medicine, were termed 'Rasashaastra', which means the "Science of Mercury". which has eventually become known as Iatrochemistry in current terminology. Much of the focus of 'Rasashaastra' was on the processing of these metals to become ingestible by the human body. The therapeutic effect of the materials such as metals and minerals that were known to be indigestible by the human body were combined with plants or animal materials to increase their delivery ability to human body.
+
+== See also ==
+Antivenom
+
+== References ==
+
+== Further reading ==
+"Iatrochemistry" . Encyclopædia Britannica. Vol. 14 (11th ed.). 1911.
+Conrad, Lawrence; Nutton, Vivian; et al. The Western Medical Tradition: 800 BC To AD 1800. Cambridge University Press, 1995.
+Debus, Allen G., The English Paracelsians. [Franklin Watts, Inc., New York], 1965.
+Lawrence M. Principe,  "Transmutations: Alchemy in Art."  CHP publications.  ISBN 0-941901-32-7
+Lawrence M. Principe,  "The Secrets of Alchemy."  The University of Chicago Press, 2013.  ISBN 978-0-226-92378-9
+Mary Lindemann, "Medicine and Society in Early Modern Europe."  Cambridge University Press, 2010.  ISBN 978-0-521-42592-6

data/en.wikipedia.org/wiki/Timeline_of_the_gunpowder_age-0.md

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+---
+title: "Timeline of the gunpowder age"
+chunk: 1/3
+source: "https://en.wikipedia.org/wiki/Timeline_of_the_gunpowder_age"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:20.945893+00:00"
+instance: "kb-cron"
+---
+
+This is a timeline of the history of gunpowder and related topics such as weapons, warfare, and industrial applications. The timeline covers the history of gunpowder from the first hints of its origin as a Taoist alchemical product in China until its replacement by smokeless powder in the late 19th century (from 1884 to the present day).
+
+== Pre-gunpowder formula ==
+Major developments: Earliest stage of gunpowder development. Mentions of gunpowder ingredients and their uses in conjunction with each other.
+
+== 9th century ==
+Major developments: Earliest definite references to a gunpowder formula and awareness of its danger.
+
+== 10th century ==
+Major developments: Gunpowder is utilized in Chinese warfare and an assortment of gunpowder weapons appear. Fire arrows utilizing gunpowder as an incendiary appear in the early 900s and possibly rocket arrows as well by the end of the century. The gunpowder slow match is used for igniting flame throwers. The ancestor of firearms, the fire lance, also appears, but its usage in the 10th century is uncertain and no textual evidence for it exists during this period. 
+
+== 11th century ==
+Major developments: The chemical formula for gunpowder is recorded in the Wujing Zongyao by 1044. Bombs appear in the early 11th century. Gunpowder becomes more common in the Song dynasty and production of gunpowder weapons is systematized. The Song court restricts trade of gunpowder ingredients with the Liao and Western Xia dynasties.
+
+== 12th century ==
+Major developments: Gunpowder fireworks are mentioned. Ships are equipped with trebuchets for hurling bombs. Earliest recorded usage of gunpowder artillery in ship to ship combat, first mention of the fire lance in battle, and the earliest possible depiction of a cannon appears.
+
+== 13th century ==
+Major developments: Bomb shells gain an iron casing. Fire lances are equipped with projectiles and reusable iron barrels. Rockets are used in warfare. "Fire emitting tubes" are produced in the Song dynasty by the mid-13th century and hand cannons are recorded to have been used in battle by the Yuan dynasty in 1287. The earliest extant cannons appear in China. The Mongols spread gunpowder weaponry to Japan, Southeast Asia, and possibly the Middle East as well as Europe. Europe and India both acquire gunpowder by the end of the century, but only in the Middle East are gunpowder weapons mentioned in any detail.
+
+== 14th century ==
+Major developments: Chinese gunpowder weaponry continues to advance with the development of one-piece cast iron cannons, accompanying carriages, and the addition of land mines, naval mines and rocket launchers. Earliest recorded instance of volley fire with gunpowder weaponry, by the Ming dynasty. The rest of the world catches up quickly and most of Eurasia acquires gunpowder weapons by the second half of the 14th century. Cannon development in Europe progresses rapidly and by 1374, cannons in Europe are able to breach a city wall for the first time. Breech loading cannons appear in Europe.
+
+== 15th century ==
+Major developments: Large-calibre artillery weighing several thousand kg are produced in Europe during the early 15th century and spread to the Ottoman Empire. Modifiable two wheeled gun carts known as limbers and caissons appear, greatly improving the mobility of artillery. The matchlock arquebus, the first firearm with a trigger mechanism, appears in Europe by 1475. Rifled barrels also appear in the late 15th century. The term musket is used for the first time in 1499. Rocket launchers are used in battle by the Ming dynasty and the Korean kingdom of Joseon develops a mobile rocket launcher vehicle called the hwacha. Chinese style bombs are used in Japan by 1468 at the latest.
+
+== 16th century ==
+Major developments: Matchlock firearms spread throughout Eurasia, reaching China and Japan by the mid-16th century. The volley fire technique is implemented using matchlock firearms by the Ottomans, Ming dynasty, and Dutch Republic by the end of the century. The arquebus is replaced by its heavier variant called the musket to combat heavily armoured troops. "Musket" becomes the dominant term for all shoulder arms fireweapons until the mid-19th century. The wheellock and flintlock trigger mechanisms are invented. Pistols and revolvers both appear during this period. Ottoman troops attach bayonets to their firearms. Both Europe and China develop handheld breech loading firearms. The star fort spreads across Europe in response to increasing effectiveness of siege artillery. The Ming dynasty uses gunpowder for hydraulic engineering. 
+
+== 17th century ==
+Major developments: Bayonets spread across Eurasia. A paper cartridge is introduced by Gustavus Adolphus. Rifles are used for war by Denmark. A ship of the line carrying 60 to 120 cannons appears in Europe. Samuel Pepys' diary mentions a machine gun like pistol. The "true" flintlock replaces the snaphance flintlock in Europe by the end of the 17th century. Both China and Japan reject the flintlock and the Mughal Empire only uses it in limited quantities. Gunpowder is used for mining in Europe.
+
+== 18th century ==
+Major developments: Flintlocks completely displace matchlock firearms in Europe both on land and at sea. Sir William Congreve, 1st Baronet discovers "cylinder powder", gunpowder produced using charcoal in iron cylinders, which is twice as powerful as traditional gunpowder and less likely to spoil. He also invents block trail carriages, the most advanced artillery transport of the time. James Puckle invents a breechloader flintlock capable of firing 63 shots in seven minutes. The Kingdom of Mysore deploys iron cased rockets known as Mysorean rockets.

data/en.wikipedia.org/wiki/Timeline_of_the_gunpowder_age-1.md

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+---
+title: "Timeline of the gunpowder age"
+chunk: 2/3
+source: "https://en.wikipedia.org/wiki/Timeline_of_the_gunpowder_age"
+category: "reference"
+tags: "science, encyclopedia"
+date_saved: "2026-05-05T16:15:20.945893+00:00"
+instance: "kb-cron"
+---
+
+== 19th century ==
+Major developments: Sir William Congreve, 2nd Baronet develops the Congreve rockets based on Mysorean rockets and British forces successfully deploy them against Copenhagen. Joshua Shaw invents percussion caps which replace the flintlock trigger mechanism. Claude-Étienne Minié invents the Minié ball, making rifles a viable military firearm, ending the era of smoothbore muskets. Subsequently rifles are deployed in the Crimean War with resounding success. Benjamin Tyler Henry invents the Henry rifle, the first reliable repeating rifle. Richard Jordan Gatling invents the Gatling gun, capable of firing 200 cartridges in a minute. Hiram Maxim invents the Maxim gun, the first single-barreled machine gun. Both China and Europe start using cast iron molds for casting cannons. Alfred Nobel invents dynamite, the first stable explosive stronger than gunpowder. Smokeless powder is invented and replaces the traditional "black powder" in Europe by the end of the century.
+
+== 20th century ==
+Major developments: Smokeless powder replaces traditional "black powder" across the globe, ending the gunpowder age.
+
+== See also ==
+Timeline of the gunpowder age in Japan
+Timeline of the gunpowder age in Korea
+Timeline of the gunpowder age in South Asia
+Timeline of the gunpowder age in Southeast Asia
+
+== Citations ==