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1789 In Science
The year 1789 in science and technology involved some significant events. Anatomy * Antonio Scarpa publishes ''Anatomicæ disquisitiones de auditu et olfactu'', a classic treatise on the hearing and olfactory organs. Astronomy * August 28 and September 17 – William Herschel discovers Saturn's moons Enceladus and Mimas, which he describes to the Royal Society of London on November 12. * Maximilian Hell establishes the constellations '' Tubus Hershelli Major'' and ''Minor'' in honour of Herschel's discovery of Uranus (constellations obsolete by 1930). Botany * Erasmus Darwin publishes his poem '' The Loves of the Plants'', a popular rendering of Linnaeus' works. * Antoine Laurent de Jussieu publishes Genera Plantarum: secundum ordines naturales disposita, juxta methodum in Horto regio parisiensi exaratam, anno M.DCC.LXXIV', providing a basis for the system of natural classification of flowering plants largely still in use. Chemistry * Antoine Lavoisier's '' Traité élémenta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta. Angiosperms are by far the most diverse group of Embryophyte, land plants with 64 Order (biology), orders, 416 Family (biology), families, approximately 13,000 known Genus, genera and 300,000 known species. They include all forbs (flowering plants without a woody Plant stem, stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. Angiosperms are distinguished from the other major seed plant clade, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slovenes
The Slovenes, also known as Slovenians ( ), are a South Slavs, South Slavic ethnic group native to Slovenia and adjacent regions in Italy, Austria and Hungary. Slovenes share a common ancestry, Slovenian culture, culture, and History of Slovenia, history, and speak Slovene language, Slovene as their native language. Although Slovenes are linguistically classified as South Slavs, genetic studies indicate they share closer genetic affinities with West Slavic and Central European populations than with other South Slavs such as Bulgarians and Macedonians. Outside of Slovenia and Europe, Slovenes form diaspora groups in the United States, Canada, Argentina and Brazil. Population Population in Slovenia Most Slovenes today live within the borders of the independent Slovenia (2,100,000 inhabitants, 83% Slovenes est. July 2020). In the Slovenian national census of 2002, 1,631,363 people ethnically declared themselves as Slovenes, while 1,723,434 people claimed Slovene as their nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mackenzie River
The Mackenzie River (French: ; Slavey language, Slavey: ' [tèh tʃʰò], literally ''big river''; Inuvialuktun: ' [kuːkpɑk], literally ''great river'') is a river in the Canadian Canadian boreal forest, boreal forest and tundra. It forms, along with the Slave River, Slave, Peace River, Peace, and Finlay River, Finlay, the longest river system in Canada, and includes the second largest drainage basin of any North American river after the Mississippi River, Mississippi. The Mackenzie River flows through a vast, thinly populated region of forest and tundra entirely within the Northwest Territories in Canada, although its many tributaries reach into five other Provinces and territories of Canada, Canadian provinces and territories. The river's mainstem (hydrology), main stem is long, flowing north-northwest from Great Slave Lake into the Arctic Ocean, where it forms a large River delta, delta at its mouth. Its extensive watershed drains about 20 percent of Canada. It is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Mackenzie (explorer)
Sir Alexander Mackenzie ( – 12 March 1820) was a Scottish explorer and fur trader known for accomplishing the first crossing of North America north of Mexico by a European in 1793. The Mackenzie River and Mount Sir Alexander are named after him. As a leading member of the North West Company, he aspired to extend the Company's operations into western Canada and selling those furs in China. His hopes thus were intrusions on the monopoly positions of both the Hudson's Bay Company and the East India Company. Early life Mackenzie was born in Stornoway in Isle of Lewis, Lewis. He was the third of the four children born to Kenneth 'Corc' Mackenzie (1731–1780) and his wife Isabella MacIver, from another prominent mercantile family in Stornoway. When only 14 years old, Mackenzie's father served as an Ensign (rank), ensign to protect Stornoway during the Jacobite rising of 1745. He later became a merchant and held the Tacksman, tack of Melbost; his grandfather being a younger brot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitchblende
Uraninite, also known as pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium causes the mineral to contain oxides of lead and trace amounts of helium. It may also contain thorium and rare-earth elements. Overview Uraninite used to be known as pitchblende (from '' pitch'', because of its black color, and ''blende'', from ''blenden'' meaning "to deceive", a term used by German miners to denote minerals whose density suggested metal content, but whose exploitation, at the time they were named, was either unknown or not economically feasible). The mineral has been known since at least the 15th century, from silver mines in the Ore Mountains, on the German/Czech border. The type locality is the historic mining and spa town known as Joachimsthal, the modern-day Jáchymov, on the Czech side of the mountains, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactive decay, radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes of uranium, isotopes, making them useful for dating the age of the Earth. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordial nuclide, primordially occurring elements. Its density is about 70% higher than that of lead and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few Parts-per notation#Parts-per expressions, parts per million in soil, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Heinrich Klaproth
Martin Heinrich Klaproth (1 December 1743 – 1 January 1817) was a German chemist. He trained and worked for much of his life as an apothecary, moving in later life to the university. His shop became the second-largest apothecary in Berlin, and the most productive artisanal chemical research center in Europe. Klaproth was a major systematizer of analytical chemistry, and an independent inventor of gravimetric analysis. His attention to detail and refusal to ignore discrepancies in results led to improvements in the use of apparatus. He was a major figure in understanding the composition of minerals and characterizing the elements. Klaproth discovered uranium (1789) and zirconium (1789). He was also involved in the discovery or co-discovery of titanium (1795), strontium (1793), cerium (1803), and chromium (1797) and confirmed the previous discoveries of tellurium (1798) and beryllium (1798). Klaproth was a member and director of the Berlin Academy of Scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annales De Chimie Et De Physique
__NOTOC__ ''Annales de chimie et de physique'' (, ) is a scientific journal founded in Paris, France, in 1789 under the title ''Annales de chimie''. One of the early editors was the French chemist Antoine Lavoisier. Lavoisier, an aristocrat, was guillotined in May 1794, ostensibly for tax fraud: and the journal was not published from 1794 to 1796 while the Reign of Terror was at its height under the French Directory. In 1815, it became the ''Annales de chimie et de physique'', and was published under that name for the next 100 years. In 1914, it split into two successor journals. The first one, '' Annales de physique'', was latterly published by EDP Sciences under the same name up to 2009, when it became integrated in the '' European Physical Journal'' series as the '' European Physical Journal H – Historical Perspectives on Contemporary Physics''. The second successor, ''Annales de chimie'', later became '' Annales de chimie: Science des matériaux'' in 1978; from 1998 to 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Journal
In academic publishing, a scientific journal is a periodical publication designed to further the progress of science by disseminating new research findings to the scientific community. These journals serve as a platform for researchers, scholars, and scientists to share their latest discoveries, insights, and methodologies across a multitude of scientific disciplines. Unlike professional or trade magazines, the articles are mostly written by scientists rather than staff writers employed by the journal. Scientific journals are characterized by their rigorous peer review process, which aims to ensure the validity, reliability, and quality of the published content. In peer review, submitted articles are reviewed by active scientists (peers) to ensure scientific rigor. With origins dating back to the 17th century, the publication of scientific journals has evolved significantly, advancing scientific knowledge, fostering academic discourse, and facilitating collaboration within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phlogiston
The phlogiston theory, a superseded scientific theory, postulated the existence of a fire-like element dubbed phlogiston () contained within combustible bodies and released during combustion. The name comes from the Ancient Greek (''burning up''), from (''flame''). The idea of a substance was first proposed in 1667 by Johann Joachim Becher and later put together more formally in 1697 by Georg Ernst Stahl. Phlogiston theory attempted to explain chemical processes such as combustion and rusting, now collectively known as oxidation. The theory was challenged by the concomitant mass increase and was abandoned before the end of the 18th century following experiments by Antoine Lavoisier in the 1770s and by other scientists. Phlogiston theory led to experiments that ultimately resulted in the identification (), and naming (1777), of oxygen by Joseph Priestley and Antoine Lavoisier, respectively. Theory Phlogiston theory states that ''phlogisticated'' substances contain phlo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Element
A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its atomic nucleus, nucleus. Atoms of the same element can have different numbers of neutrons in their nuclei, known as isotopes of the element. Two or more atoms can combine to form molecules. Some elements form Homonuclear molecule, molecules of atoms of said element only: e.g. atoms of hydrogen (H) form Diatomic molecule, diatomic molecules (H). Chemical compounds are substances made of atoms of different elements; they can have molecular or non-molecular structure. Mixtures are materials containing different chemical substances; that means (in case of molecular substances) that they contain different types of molecules. Atoms of one element can be transformed into atoms of a different element in nuclear reactions, which change an atom's at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
