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polonium

(Encyclopedia)polonium pəlōˈnēəm [key], radioactive chemical element; symbol Po; at. no. 84; mass no. of most stable isotope 209; m.p. 254℃; b.p. 962℃; sp. gr. about 9.4; valence +2 or +4. Polonium is an e...

solid

(Encyclopedia)solid, one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume....

Lister, Joseph Lister, 1st Baron

(Encyclopedia)Lister, Joseph Lister, 1st Baron, 1827–1912, English surgeon, educated at University College, London. He brought to surgery the principle of antisepsis, an outgrowth of Pasteur's theory that bacteri...

Hill, Archibald Vivian

(Encyclopedia)Hill, Archibald Vivian, 1886–1977, British physiologist, B.A. Cambridge, 1909. Hill was a professor at Manchester Univ. (1920–23) and University College, London (1923–25) before becoming a resea...

gilding

(Encyclopedia)gilding, process of applying a thin layer of real or imitation gold to a surface. The process is employed on wood, metal, ivory, leather, paper, glass, porcelain, and fabrics and is used to embellish ...

polychlorinated biphenyl

(Encyclopedia)polychlorinated biphenyl or PCB, any of a group of organic compounds originally widely used in industrial processes but later found to be dangerous environmental pollutants. Polychlorinated biphenyl i...

potassium hydroxide

(Encyclopedia)potassium hydroxide, chemical compound with formula KOH. Pure potassium hydroxide forms white, deliquescent crystals. For commercial and laboratory use it is usually in the form of white pellets. A st...

succulent

(Encyclopedia)succulent sŭkˈyələnt [key], any fleshy plant that belongs to one of many diverse families, among them species of cactus, aloe, stonecrop, houseleek, agave, and yucca. Most succulents are indigenou...

Micah, book of the Bible

(Encyclopedia)Micah mīˈkə [key], 6th of the books of the Minor Prophets of the Bible, containing the oracles of the prophet Micah, a contemporary of Isaiah whose career spanned the period c.750–c.700 b.c. The ...

Lewis, Meriwether

(Encyclopedia)Lewis, Meriwether, 1774–1809, American explorer, one of the leaders of the Lewis and Clark expedition, b. near Charlottesville, Va. He was a captain in the army and served in a number of campaigns a...