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Nott, Eliphalet

(Encyclopedia)Nott, Eliphalet ĭlĭfˈəlĭt [key], 1773–1866, American educator, inventor, and clergyman, b. Ashford, Conn. In 1804, Nott became president of Union College, a post he held for 62 years; he initia...

Brown-Séquard, Charles Édouard

(Encyclopedia)Brown-Séquard, Charles Édouard broun-sākärˈ, –sākwärˈ [key], 1817–94, physiologist, b. Mauritius, of French and American parents. He taught at Harvard (1864–68), practiced medicine in Ne...

machine tool

(Encyclopedia)machine tool, power-operated tool used for finishing or shaping metal parts, especially parts of other machines. An establishment that is equipped with such tools and specializes in such work is known...

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...