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dogbane

(Encyclopedia)dogbane, common name for some members of the Apocynaceae, a family of herbs, shrubs, and trees found in most parts of the world but especially in the tropics, where they are often climbing forms. Many...

prostate gland

(Encyclopedia)prostate gland, gland that is part of the male reproductive system. It is an organ about the size of a chestnut and consists of glandular and muscular tissue. It is situated below the neck of the blad...

ratchet and pawl

(Encyclopedia)ratchet and pawl, mechanical device that permits motion in one direction only. The ratchet is usually a wheel with slanting teeth. The pawl is a lever tangential to the wheel with one end resting on t...

Appii forum

(Encyclopedia)Appii forum ăpˈēī [key] [Lat.,=Appius' market], important stop on the Appian Way, c.40 mi (64 km) E of Rome. It was at the head of a canal through the Pontine Marshes. When Paul arrived here on hi...

milkweed

(Encyclopedia)milkweed, common name for members of the Asclepiadaceae, a family of mostly perennial herbs and shrubs characterized by milky sap, a tuft of silky hairs attached to the seed (for wind distribution), a...

thermometer

(Encyclopedia)thermometer, instrument for measuring temperature. Galileo and Sanctorius devised thermometers consisting essentially of a bulb with a tubular projection, the open end of which was immersed in a liqui...

Hertzsprung-Russell diagram

(Encyclopedia)CE5 The Hertzsprung-Russell diagram shows the relation between the luminosity and surface temperature (which is related to spectral class, or color) of the stars in the Milky Way. Most stars fall a...

community chest

(Encyclopedia)community chest, cooperative organization of citizens and social welfare agencies in a city. Also known as a united fund, it has two purposes: to raise funds through an annual campaign for its member ...

morning glory

(Encyclopedia)CE5 Morning glory, Convolvulus arvensis morning glory, common name for members of the Convolvulaceae, a family of herbs, shrubs, and small trees (many of them climbing forms) inhabiting warm regio...

cosmology

(Encyclopedia)cosmology, area of science that aims at a comprehensive theory of the structure and evolution of the entire physical universe. The earliest pre-Ptolemaic theories assumed that the earth was the cent...