Davy, Humphry

Davy, Humphry. Elements of Chemical Philosophy. London Printed for J. Johnson [by W. Bulmer], 1812. 

In later years, Gay-Lussac continued to advance science. He developed a precise method for analyzing the alcoholic content of liquors and patented a method for the manufacture of sulfuric acid. His last publication on aqua regia (a mixture of nitric and hydrochloric acids that dissolves gold or platinum) came out the year before his death in 1850. Gay-Lussac was a top-notch experimentalist and theoretician. More than twenty-five years after Gay-Lussac died, the prominent chemist Marcellin Bertholet (1827-1907) once said, We all teach. . . the chemistry of Lavoisier and Gay-Lussac (Crosland, p. 248), a fitting tribute to two outstanding scientists of the era. see also Acid-Base Chemistry Berthollet, Claude-Louis Charles, Jacques Dalton, John Davy, Humphry Lavoisier, Antoine. 

Regioselectivity in the formation of regioisomers is also observed in electrophilic aromatic substitution reactions. In the case of monosubstituted benzene derivatives, there are three possible regiosomeric products that form at different rates, based on the mechanism of the reaction (see Figure 13). see also Berzelius, Jons Jakob Chirality Dalton, John Davy, Humphry Molecular Structure Scheele, Carl Wohler, Friedrich. 

Davy, Humphry. Fragmentary Remains. John Churchill, London. 1858. Davy, Humphry. The Collected Works of Sir Humphry Davy. Volume I. London. 1839-1840. 

Because of their metallic and alkaline properties, potassium and especially sodium are widely used in a variety of industrial processes both as metals and as compounds with various other elements. Lithium is rarely used, but does find application in lightweight alloys with magnesium. Rubidium and cesium are not commonly utilized industrially, except for some applications in electronics. Sodium and potassium are essential for life, sodium being the principal extracellular and potassium the major intracellular monovalent cations. The other alkali metals have no essential biological role, see ALSO Bunsen, Robert Cesium Davy, Humphry Francium Lithium Mendeleev, Dimitri Potassium Rubidium Sodium. 

Because of their metallic properties and low mass, Be and Mg are used to form lightweight alloys for structural purposes. Ca sees less industrial use, although the phosphate is sometimes utifized in fertilizers. Sr and Ba have no significant industrial applications. Both Be and Ra are used in various devices, the former because it is quite transparent to x-rays and the latter because it is a ready source of both a- and y-radiation. Mg and Ca are essential to all living systems for many reasons the other alkali earths have no known biological roles, see also Beryllium Cesium Curie, Marie Sklodowska Davy, Humphry Francium Magnesium Potassium Rubidium Wohler, Friedrich. 

Sodium borohydride is marketed in powdered or pellet form, and in solution, for use in fuel cells. Boron nitride can withstand temperatures of up to 650°C (1,202°E) when subjected to high pressures and temperatures, it forms cubic crystals whose hardness rivals that of diamond. Boron carbide, produced by reacting coke and boric acid at 2,600°C (4,712°E), is a highly refractory material and one of the hardest substances known. It has both abrasive and abrasion-resistant applications, and is used in nuclear shielding, see ALSO Davy, Humphry Gay-Lussac, Joseph-Louis Nuclear Chemistry. 

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