Columbia Encyclopedia

Search results

144 results found

norepinephrine

(Encyclopedia)norepinephrine nôrˌĕpīnĕfˈrən [key], a neurotransmitter in the catecholamine family that mediates chemical communication in the sympathetic nervous system, a branch of the autonomic nervous sys...

verbena

(Encyclopedia)CE5 Hoary vervain, Verbena stricta verbena, common name for some members of the Verbenaceae, a family of herbs, shrubs, and trees (often climbing forms) of warmer regions of the world. Well-known ...

adsorption

(Encyclopedia)adsorption, adhesion of the molecules of liquids, gases, and dissolved substances to the surfaces of solids, as opposed to absorption, in which the molecules actually enter the absorbing medium (see a...

Rossetti, Dante Gabriel

(Encyclopedia)Rossetti, Dante Gabriel rōsĕtˈē [key], 1828–82, English poet and painter; son of Gabriele Rossetti and brother of Christina Rossetti. He attended the Royal Academy and studied painting briefly ...

petroleum

(Encyclopedia)petroleum, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth; it is also called crude oil. It consists principally of a mixture of hydrocarbons, with t...

gas, fuel

(Encyclopedia)gas, fuel, gaseous substance that burns in air and releases enough heat to be useful as a fuel, while also remaining sufficiently stable at ordinary temperatures to permit long-term storage without de...

ester

(Encyclopedia)CE5 Esters ester, any one of a group of organic compounds with general formula RCO2R′ (where R and R′ are alkyl groups or aryl groups) that are formed by the reaction between an alcohol and an...

olive oil

(Encyclopedia)olive oil, pale yellow to greenish oil obtained from the pulp of olives by separating the liquids from solids. Olive oil was used in the ancient world for lighting, in the preparation of food, and as ...

bleaching

(Encyclopedia)bleaching, process of whitening by chemicals or by exposure to sun and air, commonly applied to textiles, paper pulp, wheat flour, petroleum products, oils and fats, straw, hair, feathers, and wood. C...

Turner, Joseph Mallord William

(Encyclopedia)Turner, Joseph Mallord William, 1775–1851, English landscape painter, b. London. Turner was the foremost English romantic painter and the most original of English landscape artists; in watercolor he...