Carl Wilhelm Scheele
|Died||21 May 1786 43) (aged|
|Known for||Discovered oxygen (independently), molybdenum, manganese, barium, chlorine, tungsten and more|
Carl Wilhelm Scheele (German: [ˈʃeːlə] , Swedish: [ˈɧêːlɛ] ; 9 December 1742 – 21 May 1786) was a Swedish Pomeranian and German pharmaceutical chemist. Isaac Asimov called him "hard-luck Scheele" because he made a number of chemical discoveries before others who are generally given the credit. For example, Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, hydrogen, and chlorine before Humphry Davy, among others. Scheele discovered organic acids tartaric, oxalic, uric, lactic, and citric, as well as hydrofluoric, hydrocyanic, and arsenic acids. He preferred speaking German to Swedish his whole life, as German was commonly spoken among Swedish pharmacists.
Scheele was born in Stralsund, in western Pomerania, which at the time was a Swedish Dominion inside the Holy Roman Empire. Scheele's father Joachim (or Johann) Christian Scheele, was a grain dealer and brewer from a respected German family. His mother was Margaretha Eleanore Warnekros.
Friends of Scheele's parents taught him the art of reading prescriptions and the meaning of chemical and pharmaceutical signs.Then, in 1757, at age fourteen Carl was sent to Gothenburg as an apprentice pharmacist with another family friend and apothecary. (Martin Andreas Bauch). Scheele retained this position for eight years. During this time he ran experiments late into the night and read the works of Nicolas Lemery, Caspar Neumann, Johann von Löwenstern-Kunckel and Georg Ernst Stahl (the champion of the phlogiston theory). Much of Scheele's later theoretical speculations were based upon Stahl.
In 1765 Scheele worked under the progressive and well informed apothecary, C. M. Kjellström in Malmö, and became acquainted with Anders Jahan Retzius who was a lecturer at the University of Lund and later a professor of chemistry at Stockholm. Scheele arrived in Stockholm between 1767 and 1769 and worked as a pharmacist. During this period he discovered tartaric acid and with his friend, Retzius, studied the relation of quicklime to calcium carbonate. While in the capital, he also became acquainted with many luminaries, such as: Abraham Bäck, Peter Jonas Bergius, Bengt Bergius and Carl Friedreich von Schultzenheim.
In the fall of 1770 Scheele became director of the laboratory of the great pharmacy of Locke, at Uppsala which is about 40 miles north of Stockholm. The laboratory supplied chemicals to Professor of Chemistry Torbern Bergman. A friendship developed between Scheele and Bergman after Scheele analyzed a reaction which Bergman and his assistant Johan Gottlieb Gahn could not resolve. The reaction was between melted saltpetre and acetic acid which produced a red vapor. Further study of this reaction later led to Scheele's discovery of oxygen (see "The theory of phlogiston" below). Based upon this friendship and respect Scheele was given free use of Bergman's laboratory. Both men were profiting from their working relationship. In 1774 Scheele was nominated by Peter Jonas Bergius to be a member of the Royal Swedish Academy of Sciences and was elected February 4, 1775. In 1775 Scheele also managed for a short time a pharmacy in Köping. Between the end of 1776 and the beginning of 1777 Scheele established his own business there.
On October 29, 1777, Scheele took his seat for the first, and only time, at a meeting of the Academy of Sciences and on November 11 passed the examination as apothecary before the Royal Medical College and did so with highest honours. After his return to Köping he devoted himself, outside of his business, to scientific researches which resulted in a long series of important papers.
By the time he was a teenager, Scheele had learned the dominant theory of gases which in the 1770s was the phlogiston theory. Phlogiston, classified as "matter of fire", was supposed to be released from any burning material, and when it was exhausted, combustion would stop. When Scheele discovered oxygen he called it "fire air" as it supported combustion. Scheele explained oxygen using phlogistical terms because he did not believe that his discovery disproved the phlogiston theory.
Before Scheele made his discovery of oxygen, he studied air. Air was thought to be an element that made up the environment in which chemical reactions took place but did not interfere with the reactions. Scheele's investigation of air enabled him to conclude that air was a mixture of "fire air" and "foul air;" in other words, a mixture of two gases. Scheele performed numerous experiments in which he heated substances such as saltpetre (potassium nitrate), manganese dioxide, heavy metal nitrates, silver carbonate and mercuric oxide. In all of these experiments, he isolated the same gas: his "fire air," which he believed combined with phlogiston in materials to be released during heat-releasing reactions.
However, his first publication, Chemische Abhandlung von der Luft und dem Feuer, was delivered to the printer Swederus in 1775, but not published until 1777, at which time both Joseph Priestley and Lavoisier had already published their experimental data and conclusions concerning oxygen and the phlogiston theory. Carl was credited for finding oxygen with two other people, Joseph Priestley and Antoine Lavoisier. The first English edition, Chemical Observation and Experiments on Air and Fire was published in 1780, with an introduction "Chemical Treatise on Air and Fire".
Scheele achieved astonishingly prolific and important results without the expensive laboratory equipment to which his Parisian contemporary Antoine-Laurent Lavoisier was accustomed. Through the studies of Lavoisier, Joseph Priestley, Scheele, and others, chemistry was made a standardized field with consistent procedures. Although Scheele was unable to grasp the significance of his discovery of the substance that Lavoisier later named oxygen, his work was essential for the abandonment of the long-held theory of phlogiston.
Scheele's study of the gas not yet named oxygen was prompted by a complaint by Torbern Olof Bergman, a professor at Upsala University who would eventually become Scheele's friend. Bergman informed Scheele that the saltpeter he had purchased from Scheele's employer, after long heating, produced red vapors (now known to be nitrogen dioxide) when it came into contact with acetic acid. Scheele's quick explanation was that the saltpeter had absorbed phlogiston with the heat (had been reduced to nitrite, in modern terms) and gave off a new phlogisticated gas as an active principle when combined with an acid (even a weak acid).
Bergman next suggested that Scheele analyze the properties of manganese (IV) oxide. It was through his studies of manganese(IV)oxide that Scheele developed his concept of "fire air" (his name for oxygen). He ultimately obtained oxygen by heating mercuric oxide, silver carbonate, magnesium nitrate, and other nitrate salts. Scheele wrote about his findings to Lavoisier who was able to see the significance of the results. His discovery of oxygen (ca. 1771) was chronologically earlier than the corresponding work of Priestley and Lavoisier, but he did not publish this discovery until 1777, after both of his rivals had published.
Although Scheele would always believe in some form of the phlogiston theory, his work reduced phlogiston to an unusually simple form, complicated only by the fact that chemists of Scheele's day still believed that light and heat were elements and were to be found in combination with them. Thus, Scheele assumed that hydrogen was composed of phlogiston (a reducing principle lost when objects were burned) plus heat. Scheele speculated that his fire air or oxygen (which he found the active part of air, estimating it to compose one quarter of air) combined with the phlogiston in objects to produce either light or heat (light and heat were presumed to be composed of differing proportions of phlogiston and oxygen).
When other chemists later showed water is produced when burning hydrogen and that rusting of metals added weight to them and that passing water over hot iron gave hydrogen, Scheele modified his theory to suggest that oxygen was the salt (or "saline principle" of water), and that when added to iron, water was reproduced, which added weight to the iron as rust.
In addition to his joint recognition for the discovery of oxygen, Scheele is argued to have been the first to discover other chemical elements such as barium (1772),manganese (1774), molybdenum (1778), and tungsten (1781), as well as several chemical compounds, including citric acid, lactic acid, glycerol, hydrogen cyanide (also known, in aqueous solution, as prussic acid), hydrogen fluoride, and hydrogen sulfide (1777). In addition, he discovered a process similar to pasteurization, along with a means of mass-producing phosphorus (1769), leading Sweden to become one of the world's leading producers of matches.
Scheele made one other very important scientific discovery in 1774, arguably more revolutionary than his isolation of oxygen. He identified lime, silica, and iron in a specimen of pyrolusite (impure manganese dioxide) given to him by his friend, Johann Gottlieb Gahn, but could not identify an additional component (this was the manganese, which Scheele recognized was present as a new element, but could not isolate). When he treated the pyrolusite with hydrochloric acid over a warm sand bath, a yellow-green gas with a strong odor was produced.He found that the gas sank to the bottom of an open bottle and was denser than ordinary air. He also noted that the gas was not soluble in water. It turned corks a yellow color and removed all color from wet, blue litmus paper and some flowers. He called this gas with bleaching abilities, "dephlogisticated muriatic acid" (dephlogisticated hydrochloric acid, or oxidized hydrochloric acid). Eventually, Sir Humphry Davy named the gas chlorine.
Chlorine's bleaching properties were eventually turned into an industry by Berzelius, and became the foundation of a second industry of disinfection and deodorization of putrefied tissue and wounds (including wounds in living humans) in the hands of Labarraque, by 1824.
In the fall of 1785, Scheele began to suffer from symptoms described as kidney disease. In early 1786, he also contracted a disease of the skin, which, combined with kidney problems, so enfeebled him that he could foresee an early death. With this in mind, he married the widow of his predecessor,Pohl, two days before he died, so that he could pass undisputed title to his pharmacy and his possessions to her.
While Scheele's experiments generated substances which have long since been found to be hazardous, the compounds and elements he used to start his experiments were dangerous to begin with, especially heavy metals. Like most of his contemporaries, in an age where there were few methods of chemical characterisation, Scheele would smell and taste any new substances he discovered.Cumulative exposure to arsenic, mercury, lead, their compounds and perhaps hydrofluoric acid which he had discovered, as well as other substances took their toll on Scheele, who died at the early age of 43, on 21 May 1786, at his home in Köping. Doctors said that he died of mercury poisoning.
All of the following papers were published by Scheele within a span of fifteen years.
Scheele's papers appeared first in the Transactions of the Swedish Academy of Sciences, and in various periodicals such as Lorenz Florenz Friedrich von Crell's Chemische Annalen . Scheele's work was collected and published in four languages beginning with Mémoires de Chymie by Mme. Claudine Picardet in 1785 and Chemical Essays by Thomas Beddoes in 1786, followed by Latin and German.Another English translation was published by Dr Leonard Dobbin, in 1931.
Antoine-Laurent de Lavoisier, also Antoine Lavoisier after the French Revolution, was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology. He is widely considered in popular literature as the "father of modern chemistry".
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. After hydrogen and helium, oxygen is the third-most abundant element in the universe by mass. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O
2. Diatomic oxygen gas constitutes 20.95% of the Earth's atmosphere. As compounds including oxides, the element makes up almost half of the Earth's crust.
The phlogiston theory is a superseded scientific theory that postulated that a fire-like element called phlogiston is contained within combustible bodies and released during combustion. The name comes from the Ancient Greek φλογιστόν phlogistón, from φλόξ phlóx (flame). It was first stated in 1667 by Johann Joachim Becher and then put together more formally by Georg Ernst Stahl. The theory attempted to explain processes such as combustion and rusting, which are now collectively known as oxidation.
Arsine (IUPAC name: arsane) is an inorganic compound with the formula AsH3. This flammable, pyrophoric, and highly toxic pnictogen hydride gas is one of the simplest compounds of arsenic. Despite its lethality, it finds some applications in the semiconductor industry and for the synthesis of organoarsenic compounds. The term arsine is commonly used to describe a class of organoarsenic compounds of the formula AsH3−xRx, where R = aryl or alkyl. For example, As(C6H5)3, called triphenylarsine, is referred to as "an arsine".
Malic acid is an organic compound with the molecular formula C4H6O5. It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms (L- and D-enantiomers), though only the L-isomer exists naturally. The salts and esters of malic acid are known as malates. The malate anion is an intermediate in the citric acid cycle.
The year 1780 in science and technology involved some significant events.
Johan Gadolin was a Finnish chemist, physicist and mineralogist. Gadolin discovered a "new earth" containing the first rare-earth compound yttrium, which was later determined to be a chemical element. He is also considered the founder of Finnish chemistry research, as the second holder of the Chair of Chemistry at the Royal Academy of Turku. Gadolin was ennobled for his achievements and awarded the Order of Saint Vladimir and the Order of Saint Anna.
The history of chemistry represents a time span from ancient history to the present. By 1000 BC, civilizations used technologies that would eventually form the basis of the various branches of chemistry. Examples include extracting metals from ores, making pottery and glazes, fermenting beer and wine, extracting chemicals from plants for medicine and perfume, rendering fat into soap, making glass, and making alloys like bronze.
Tungstic acid refers to hydrated forms of tungsten trioxide, WO3. Both a monohydrate (WO3·H2O) and hemihydrate (WO3·0.5H2O) are known. Molecular species akin to sulfuric acid, i.e. (HO)2WO2 are not observed.
Adolph Modéer (1738–1799) was a Swedish surveyor, economic historian and naturalist. As a naturalist he was mainly interested in malacology and entomology. He also worked on jellyfish. As an economic historian, he wrote on the history of Sweden's trade.
The chemical revolution, also called the first chemical revolution, was the early modern reformulation of chemistry that culminated in the law of conservation of mass and the oxygen theory of combustion. During the 19th and 20th century, this transformation was credited to the work of the French chemist Antoine Lavoisier. However, recent work on the history of early modern chemistry considers the chemical revolution to consist of gradual changes in chemical theory and practice that emerged over a period of two centuries. The so-called scientific revolution took place during the sixteenth and seventeenth centuries whereas the chemical revolution took place during the seventeenth and eighteenth centuries.
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. 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 and Fire Air ("Feuerluft"); afterwards these components came to be known as nitrogen and oxygen, respectively.
Marie-Anne Pierrette Paulze was a French chemist and noblewoman. Madame Lavoisier was the wife of the chemist and nobleman Antoine Lavoisier, and acted as his laboratory companion and contributed to his work. She played a pivotal role in the translation of several scientific works, and was instrumental to the standardization of the scientific method.
This timeline of chemistry lists important works, discoveries, ideas, inventions, and experiments that significantly changed humanity's understanding of the modern science known as chemistry, defined as the scientific study of the composition of matter and of its interactions. The history of chemistry in its modern form arguably began with the Irish scientist Robert Boyle, though its roots can be traced back to the earliest recorded history.
Pneumatic chemistry is a term most-closely identified with an area of scientific research of the seventeenth, eighteenth, and early nineteenth centuries. Important goals of this work were an understanding of the physical properties of gases and how they relate to chemical reactions and, ultimately, the composition of matter.
Experiments and Observations on Different Kinds of Air (1774–86) is a six-volume work published by 18th-century British polymath Joseph Priestley which reports a series of his experiments on "airs" or gases, most notably his discovery of oxygen gas.
Traité élémentaire de chimie is a textbook written by Antoine Lavoisier published in 1789 and translated into English by Robert Kerr in 1790 under the title Elements of Chemistry in a New Systematic Order containing All the Modern Discoveries. It is considered to be the first modern chemical textbook.
Chemistry: A Volatile History is a 2010 BBC documentary on the history of chemistry presented by Jim Al-Khalili. It was nominated for the 2010 British Academy Television Awards in the category Specialist Factual.
Robert Porrett (1783–1868) was an English amateur chemist and antiquary.
Claudine Picardet was a chemist, mineralogist, meteorologist and scientific translator. Among the French chemists of the late eighteenth century she stands out for her extensive translations of scientific literature from Swedish, English, German and Italian to French. She translated three books and thousands of pages of scientific papers, which were published as well as circulated in manuscript form. She hosted renowned scientific and literary salons in Dijon and Paris, and was an active participant in the collection of meteorological data. She helped to establish Dijon and Paris as scientific centers, substantially contributing to the spread of scientific knowledge during a critical period in the chemical revolution.
|Wikimedia Commons has media related to Carl Wilhelm Scheele .|
|Wikiquote has quotations related to: Chemical Observations and Experiments on Air and Fire|