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Calomel is a powder that is white when pure, and it has been used as a pigment in painting in 17th century South Americas art and in European medieval manuscripts. [14] When it is exposed to light or contains impurities it takes on a darker tint. [7] Calomel is made up of mercury and chlorine with the chemical formula Hg 2 Cl 2. Depending on ...
Note: it redefines rocksalt (a rock) and defines the mineral halite. Spectroscopy (c. 1859): Gustav Robert Kirchhoff (1824–1887) and Robert Wilhelm Bunsen (1811–1899) Brothers Gustav Rose (1798–1873) and Heinrich Rose (1795–1864), German mineralogists.
The origins of rock and roll are complex.Rock and roll emerged as a defined musical style in the United States in the early to mid-1950s. It derived most directly from the rhythm and blues music of the 1940s, [1] which itself developed from earlier blues, the beat-heavy jump blues, boogie woogie, up-tempo jazz, and swing music.
During World War I Yves Le Prieur, a French naval officer (who later invented a pioneering scuba-diving apparatus), developed air-to-air solid-fuel Le Prieur rockets - used to destroy captive observation balloons (called saucisses - "sausages" in French, or Drachen - "dragons" in German) used by German artillery-spotters.
The use of rock has had a huge impact on the cultural and technological development of the human race. Rock has been used by humans and other hominids for at least 2.5 million years. [22] Lithic technology marks some of the oldest and continuously used technologies. The mining of rock for its metal content has been one of the most important ...
Invented Pop Rocks, Tang, Cool whip and Powdered Egg Whites William A. Mitchell (October 21, 1911 – July 26, 2004) was an American food chemist who, while working for General Foods Corporation between 1941 and 1976, was the key inventor behind Pop Rocks , Tang , Cool Whip , and powdered egg whites . [ 1 ]
Broken stone was wedged into the spaces between the tapered perpendicular faces to provide the layer with good lateral control. Telford kept the natural formation level and used masons to camber the upper surface of the blocks. He placed a 6-inch (15 cm) layer of stone no bigger than 2.4 in (6 cm) on top of the rock foundation.
[4] [5] He has been called "the dean of rock 'n' roll storytellers". [6] Guralnick wrote the 727-page biography of influential record producer Sam Phillips entitled Sam Phillips: The Man Who Invented Rock 'n' Roll. He also penned the script for A&E's documentary of the same name, narrated by Billy Bob Thornton.