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Sumner, James Batcheller

(Encyclopedia)Sumner, James Batcheller, 1887–1955, American biochemist, b. Canton, Mass., Ph.D. Harvard Medical School, 1914. He was a professor at Cornell from 1914 until his death in 1955. In 1946 Sumner was a ...

Bromley

(Encyclopedia)Bromley brŏmˈlē [key], outer borough of Greater London, SE England. It is the largest of t...

microelectronics

(Encyclopedia)microelectronics, branch of electronic technology devoted to the design and development of extremely small electronic devices that consume very little electric power. Although the term is sometimes us...

quartz

(Encyclopedia)quartz, one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2. It occurs in crystals of the hexagon...

Kristallnacht

(Encyclopedia)Kristallnacht krĭsˌtäl-näkht [key] [Ger.,=night of crystal], in German history, the night of Nov. 9, 1938, a night of violence against Jews and of destruction of the businesses and other property ...

sunstone

(Encyclopedia)sunstone. 1 Crystal mineral thought by some to have been used by the Vikings as an aid to navigation, especially in conditions of low visibility due to clouds or fog when the position of the sun was u...

calcium carbonate

(Encyclopedia)calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. Calci...

Kroehl, Julius Hermann

(Encyclopedia)Kroehl, Julius Hermann, 1820–67, German-American inventor and engineer, b. Memel, Prussia (now Klaipeda, Lithuania). Immigrating in 1844 to the United States, he became an iron manufacturer and civi...

amphibole

(Encyclopedia)amphibole ămˈfəbōlˌ [key], any of a group of widely distributed rock-forming minerals, magnesium-iron silicates, often with traces of calcium, aluminum, sodium, titanium, and other elements. The ...

feldspar

(Encyclopedia)feldspar fĕlˈspär [key], an abundant group of rock-forming minerals which constitute 60% of the earth's crust. Chemically the feldspars are silicates of aluminum, containing sodium, potassium, iron...