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Rocky Mountain spotted fever

(Encyclopedia)Rocky Mountain spotted fever, infectious disease caused by a rickettsia. The bacterium is harbored by wild rodents and other animals and is carried by infected ticks of several species that attach the...

Benedict's solution

(Encyclopedia)Benedict's solution, deep-blue alkaline solution used to test for the presence of the aldehyde functional group, −CHO. The substance to be tested is heated with Benedict's solution; formation of a b...

bloodletting

(Encyclopedia)bloodletting, also called bleeding, practice of drawing blood from the body in the treatment of disease. General bloodletting consists of the abstraction of blood by incision into an artery (arterioto...

beryl

(Encyclopedia)beryl bĕrˈĭl [key], mineral, a silicate of beryllium and aluminum, Be3Al2Si6O18, extremely hard, occurring in hexagonal crystals that may be of enormous size and are usually white, yellow, green, b...

zinnia

(Encyclopedia)zinnia, any species of the genus Zinnia of the family Asteraceae (aster family), native chiefly to Mexico, though some range as far north as Colorado and as far south as Guatemala. The common zinnia o...

Taxco

(Encyclopedia)Taxco täsˈkō [key], town (1990 pop. 43,836), Guerrero state, S Mexico. Founded in 1529 as a silver-mining community, Taxco was also an important stop between Mexico City and Acapulco in Spanish col...

bauxite

(Encyclopedia)bauxite bôkˈsīt, bŏkˈ– [key], mixture of hydrated aluminum oxides usually containing oxides of iron and silicon in varying quantities. A noncrystalline substance formerly thought to be a minera...

trillium

(Encyclopedia)trillium or wake-robin trĭlˈēəm [key], any plant of the large genus Trillium, attractive spring wildflowers of the family Liliaceae (lily family), native to North America and E Asia. The leaves, p...

thrush , in zoology

(Encyclopedia)thrush, bird, common name for members of the Turdidae, a large family of birds found in most parts of the world and noted for their beautiful song. The majority are modestly colored, with spotted unde...

United States, Great Seal of the

(Encyclopedia)United States, Great Seal of the, official impression that validates a United States government document. It was adopted by the Continental Congress in 1782 and, with only minor changes in the design,...