(Encyclopedia) blackjack, one of the world's most widely played gambling card games; also known as twenty-one or vingt-et-un. Despite contesting claims between the French and Italians, its origins…
(Encyclopedia) Ribot, ThéoduleRibot, Théodulerēbōˈ [key], 1839–1916, French psychologist. He was professor of experimental psychology at the Sorbonne and later at the Collège de France. His many…
(Encyclopedia) division, fundamental operation in arithmetic; the inverse of multiplication. Division may be indicated by the symbol ÷, as in 15 ÷ 3, or simply by a fraction, 15/3. The number that is…
(Encyclopedia) common-ion effect, decrease in solubility of an ionic salt, i.e., one that dissociates in solution into its ions, caused by the presence in solution of another solute that contains one…
(Encyclopedia) convection, mode of heat transfer in fluids (liquids and gases). Convection depends on the fact that, in general, fluids expand when heated and thus undergo a decrease in density (…
(Encyclopedia) hostage, person held by another as a guarantee that certain actions or promises will or will not be carried out. During periods of internal turmoil, insurgents often seize hostages;…
(Encyclopedia) glaucomaglaucomaglôkōˈmə [key], ocular disorder characterized by pressure within the eyeball caused by an excessive amount of aqueous humor (the fluid substance filling the eyeball).…
(Encyclopedia) guardian and ward, in law. A guardian is someone who by appointment or by relationship has the care of a person or that person's property, or both. The protected individual, known as…
(Encyclopedia) Jehovah's Witnesses, Christian group originating in the United States at the end of the 19th cent., organized by Charles Taze Russell, whose doctrine centers on the Second Coming of…
(Encyclopedia) melting point, temperature at which a substance changes its state from solid to liquid. Under standard atmospheric pressure different pure crystalline solids will each melt at a…
