Rosco

The element was rediscovered in 1830 by Sefstrom, who named the element in honor of the Scandinavian goddess, Vanadis, because of its beautiful multicolored compounds. It was isolated in nearly pure form by Roscoe, in 1867, who reduced the chloride with hydrogen. 

Bunsen-Roscoe law Bunte salt Bunte salts Bunte s salt Bunyavirus Buoyancy... 

Multiphoton processes are also undoubtedly involved in the photodegradation of polymers in intense laser fields, eg, using excimer lasers (13). Moreover, multiphoton excitation during pumping can become a significant loss factor in operation of dye lasers (26,27). The photochemically reactive species may or may not be capable of absorption of the individual photons which cooperate to produce multiphoton excitation, but must be capable of utilising a quantum of energy equal to that of the combined photons. Multiphoton excitation thus may be viewed as an exception to the Bunsen-Roscoe law. 

R. Roscoe, in J. J. Hermans, ed.. Flow Properties of Disperse Systems, North-HoUand Publishing Co., Amsterdam, the Netherlands, 1953, p. 1. 

A. M. del Rio in 1801 claimed to have discovered the previously unknown element 23 in a sample of Mexican lead ore and, because of the red colour of the salts produced by acidification, he called it erythronium. Unfortunately he withdrew his claim when, 4 years later, it was (incorrectly) suggested by the Frenchman, H. V. Collett-Desotils, that the mineral was actually basic lead chromate. In 1830 the element was rediscovered by N. G. Sefstrom in some Swedish iron ore. Because of the richness and variety of colours found in its compounds he called it vanadium after Vanadis, the Scandinavian goddess of beauty. One year later F. Wohler established the identity of vanadium and erythro-nium. The metal itself was isolated in a reasonably pure form in 1867 by H. E. Roscoe who reduced the chloride with hydrogen, and he was... 

Deviations from Henry s law are exhibited by most gases having absorption coefficients greater than 100. In some cases the discrepancies vanish at higher temperatures. Thus Roscoe and Dittmar (1860) found that ammonia did not follow the law of Henry at the ordinary temperature, but Sims (1862) showed that the deviations from the law became less as the temperature at which absorption occurred increased, until at 100° the amount of ammonia dissolved by water was directly proportional to the pressure. The deviations appear to be always greatest under small pressures, and to decrease with increasing pressure, and therefore with increasing concentration of the solution they are doubtless due to chemical interaction between the solvent and dissolved gas. 

Historical Introduction and Perchlorates in General History. The early history of perchlorates and the perchlorate mdustryhas been thoroughly discussed (Refs 12 14, p 2), so it will be only briefly reviewed here. Early exptl work on chlorates and perchlorates was closely tied to the discovery and identification of Cl. Several workers, notably Priestly, Lavoisier, and Scheele reported the isolation of volat liqs and gases which probably were oxides or oxyacids of Cl, but they failed to identify and characterize the compds isolated. Scheele, for example, treated muriatic ac (HCl) with Mn dioxide and obtained a volat liq which he called muriatic ac derived of its phlogiston (Ref 14, p3). The first perchlorate definitely identified was the K salt which was prepd by Stadion in 1816 by the thermal decompn of K chlorate (Ref 2). From this he prepd a hydrate of perchloric ac by heating the K salt with sulfuric ac (Ref 3). Pure (anhyd) perchloric ac was first prepd by Roscoe in 1862 by distn of the hydrated ac (Ref 4)... 

By Roscoe G. Dickinson1 and Linus Pauling Received April 24, 1923... 

By melting the calculated amounts of magnesium and tin in an iron crucible under a mixture of potassium and magnesium chlorides, and cooling slowly, a mass of magnesium stannide was obtained from which individual crystals could be cleaved. The X-ray data were obtained from Laue and spectral photographs, treated as described by Dickinson.3 I wish to express my thanks to Dr. Roscoe G. Dickinson for his advice and active interest in this research. 

Sato et al. " measured the viscosities of some binary and ternary alkali carbonates. Since melt creep must be prevented, a highly sintered alumina crucible was used instead of a gold-plated nickel crucible. Homogeneity of a mixture sample was achieved by gas bubbling. A laser beam is combined with a computer-assisted time counter to obtain the logarithmic decrement. Roscoe s equationi3i has been used for calculation of the viscosity, while it has been claimed by Abe et al. that the viscosities calculated from Roscoe s equation are 0.6-1.5% lower than those from more rigorous equations. 

Roscoe, H. E., 1901, Chemical Society Memorial Lectures 1893-1900 London, Gurney Jackson. 

P.K. Hopke, D.J. Alpert and B.A. Roscoe, FANTASIA — A program for target transformation factor analysis to apportion sources in environmental samples. Comput. Chem., 7 (1983) 149-155. 

G. Harm,J. Wittenauer and P. Roscoe, Proceedings Polymer Additives 95, Chicago, IL (1995). 

Schaeffer, G. W., J. S. Roscoe, and A. G. Stewart The Reduction of Iron(III) Chloride with Lithium Aluminohydride and Lithium Borohydride Iron(II) Borohydride. J. Amer. chem. Soc. 78, 729 (1956). 

Checked by Arthur C. Cope, William F. Gorham, and Roscoe A. Pike. 

Oxygen is not the only surface contaminant, but it is the most prevalent. Other frequent ones are sulfur (tarnish) and phosphorus. Sometimes a combination, such as chlorate (O + Cl), forms a layer. These effects are known collectively as the Roscoe Effect (Metzger and Read, 1958). 

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