Scheel

These included Scheele, Cavendish, Priestley, and others. They called it burnt or dephlogisticated air," which meant air without oxygen. 

Priestley is generally credited with its discovery, although Scheele also discovered it independently. 

Gr. chloros, greenish yellow) Discovered in 1774 by Scheele, who thought it contained oxygen. Chlorine was named in 1810 by Davy, who insisted it was an element. 

Recognized by Scheele, Bergman, and others as an element and isolated by Gahn in 1774 by reduction of the dioxide with carbon. 

Gr. molybdos, lead) Before Scheele recognized molybdenite as a distinct ore of a new element in 1778, it was confused with graphite and lead ore. The metal was prepared as an impure form in 1782 by Hjelm. Molybdenum does not occur native, but is obtained principally from molybdenite. Wulfenite, and Powellite are also minor commercial ores. 

Gr. barys, heavy) Baryta was distinguished from lime by Scheele in 1774 the element was discovered by Sir Humphrey Davy in 1808. 

Acetaldehyde [75-07-0] (ethanal), CH CHO, was first prepared by Scheele ia 1774, by the action of manganese dioxide [1313-13-9] and sulfuric acid [7664-93-9] on ethanol [64-17-5]. The stmcture of acetaldehyde was estabhshed in 1835 by Liebig from a pure sample prepared by oxidising ethyl alcohol with chromic acid. Liebig named the compound "aldehyde" from the Latin words translated as al(cohol) dehyd(rogenated). The formation of acetaldehyde by the addition of water [7732-18-5] to acetylene [74-86-2] was observed by Kutscherow] in 1881. 

Stannous fluoride probably was first prepared by Scheele in 1771 and was described by Gay-Lussac and Thenard in 1809. Commercial production of stannous fluoride is by the reaction of stannous oxide and aqueous hydrofluoric acid, or metallic tin and anhydrous hydrogen fluoride (5,6). Snp2 is also produced by the reaction of tin metal, HP, and a halogen in the presence of a nitrile (7). 

D. Elwell and H. J. Scheel, Crystal Growth from High Temperature Solution Academic Press, London, 1975. 

Lactic acid [50-21-5] (2-hydroxypropanoic acid), CH CHOHCOOH, is the most widely occurring hydroxycarboxylic acid and thus is the principal topic of this article. It was first discovered ia 1780 by the Swedish chemist Scheele. Lactic acid is a naturally occurring organic acid that can be produced by fermentation or chemical synthesis. It is present ia many foods both naturally or as a product of in situ microbial fermentation, as ia sauerkraut, yogurt, buttermilk, sourdough breads, and many other fermented foods. Lactic acid is also a principal metaboHc iatermediate ia most living organisms, from anaerobic prokaryotes to humans. 

Tartaric acid [526-83-0] (2,3-dihydroxybutanedioic acid, 2,3-dihydroxysuccinic acid), C H O, is a dihydroxy dicarboxyhc acid with two chiral centers. It exists as the dextro- and levorotatory acid the meso form (which is inactive owing to internal compensation), and the racemic mixture (which is commonly known as racemic acid). The commercial product in the United States is the natural, dextrorotatory form, (R-R, R )-tartaric acid (L(+)-tartaric acid) [87-69-4]. This enantiomer occurs in grapes as its acid potassium salt (cream of tartar). In the fermentation of wine (qv), this salt forms deposits in the vats free crystallized tartaric acid was first obtained from such fermentation residues by Scheele in 1769. 

Oxahc acid was synthesi2ed for the first time ia 1776 by Scheele through the oxidation of sugar with nitric acid. Then, Wn h1er synthesi2ed it by the hydrolysis of cyanogen [460-19-5] ia 1824. 

The oxidation of carbohydrates is the oldest method for oxahc acid manufacture. The reaction was discovered by Scheele in 1776, but was not successfully developed as a commercial process until the second quarter of the twentieth century. Technical advances in the manufacture of nitric acid, particularly in the recovery of nitrogen oxides in a form suitable for recycle, enabled its successful development. Thus 150 t of oxahc acid per month was produced from sugar by I. G. Earben (Germany) by the end of World War II. 

The discovery of oxygen, the development of a cleat understanding of the nature of air, and a knowledge of the role of oxygen in combustion and in life processes were historically important scientific achievements. In the 1770s, air and ethers were studied by such scientists as Cavendish, Ptiesdey, and Scheele. Both Scheele and Ptiesdey independendy prepared oxygen. Whereas Scheele s work remained unpubUshed until after his death, Ptiesdey was able to relate his discovery direcdy to Lavoisier in 1775. 

PyrogaHol (1) was first observed by Scheele in 1786 as a product of the dry distillation of gaUic acid [149-91-7] (3,4,5-ttihydroxybenzoic acid). PyrogaHol, which is of widespread occurrence in nature, is incorporated in tannins, anthocyanins, flavones, and alkaloids (1). 

Manufacture and Synthesis. The commercial manufacturing process is based on Scheele s original procedure starting with cmde gaHic acid. 

In 1774, Scheele deterrnined that barium oxide was a distinct oxide or "earth," and named it terra ponderosa because of its high density (1). Later, this name was changed to barote from the Greek word meaning heavy. Later stUl, the name of the oxide was modified to baryta to conform to the nomenclature recommended by Lavoisier, and from this the name barium was derived... 

The first report concerning barium compounds occurred in the early part of the seventeenth century when it was noted that the ignition of heavy spar gave a peculiar green light. A century later, Scheele reported that a precipitate formed when sulfuric acid was added to a solution of barium salts. The presence of natural barium carbonate, witherite [14941-39-0] BaCO, was noted in Scodand by Withering. 

Scheel, Lyman F., Gas Machinery, Homston, TX Gulf Publishing Company, 1972. 

Scheel, Lyman F Gas Machinery, Houston, TX Gulf Publishing Compa-nv, 1972. 

Carl-Scheele-Strafie 16 12489 Berlin-Adlershof Germany... 

Chemical Designations - Synonyms Cupric Arsenite Swedish Green Scheele s Green Cupric Green Copper Orthoarsenite Chemical Formula CuHAsO ... 

---