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barite

(Encyclopedia)barite bərīˈtēz [key] [New Lat., from barium], or heavy spar, a white, yellow, blue, red, or colorless mineral. It is a sulfate of barium, BaSO4, found in nature as tabular crystals or in granular...

Guido d'Arezzo

(Encyclopedia)Guido d'Arezzo ârətīˈnəs [key], c.990–1050, Italian Benedictine monk, known for his contributions to musical notation and theory. His theoretical work Micrologus (c.1025) is one of the principa...

perch

(Encyclopedia)perch, common name for some members of the family Percidae, symmetrical freshwater fishes of N Europe, Asia, and North America. The perches belong to the large order Perciformes (spiny-finned fishes) ...

lapwing

(Encyclopedia)lapwing, common name for some members of the family Charadriidae, which includes the plovers. Lapwings are almost all inland or upland birds, found in all temperate and tropical regions except North A...

lark

(Encyclopedia)lark, common name for members of the large family Alaudidae, perching birds of terrestrial habits, chiefly of the Old World and best-known through the skylark, Alauda arvensis. The horned larks belong...

caviar

(Encyclopedia)caviar or caviare kăvˈēär [key], the roe (eggs) of various species of sturgeon prepared as a piquant table delicacy. The ovaries of the fish are beaten to loosen the eggs, which are then freed fro...

bead test

(Encyclopedia)bead test, test used in the identification of certain metals. Some metallic ions that cannot be identified by a flame test are identified by a bead test. The test can also be used to confirm the resul...

bee fly

(Encyclopedia)bee fly, name for the small- to medium-sized flies of the family Bombyliidae, many of which resemble bees in appearance and behavior. This mimicry provides bee flies with some measure of protection ag...

tempering

(Encyclopedia)tempering, process involving slow and moderate heating to increase the hardness and toughness of metals that have undergone previous heat treatment. Metals are usually hardened (see hardening) by bein...

thistle

(Encyclopedia)thistle, popular name for many spiny and usually weedy plants, but especially applied to members of the family Asteraceae (aster family) that have spiny leaves and often showy heads of purple, rose, w...