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Calvin, Melvin

(Encyclopedia)Calvin, Melvin, 1911–97, American organic chemist and educator, b. St. Paul, Minn., grad. Michigan College of Mining and Technology, 1931, Ph.D. Univ. of Minnesota, 1935. In 1937 he joined the facul...

Wallon, Henri Alexandre

(Encyclopedia)Wallon, Henri Alexandre äNrēˈ älĕksäNˈdrə välôNˈ [key], 1812–1904, French historian and politician. He was elected (1871) to the national assembly, and it was his proposal (1875) that led...

verb

(Encyclopedia)verb, part of speech typically used to indicate an action. English verbs are inflected for person, number, tense and partially for mood; compound verbs formed with auxiliaries (e.g., be, can, have, do...

fluoridation

(Encyclopedia)fluoridation flo͝orˌĭdāˈshən [key], process of adding a fluoride to the water supply of a community to preserve the teeth of the inhabitants. Tooth enamel ordinarily contains small amounts of fl...

hydrazine

(Encyclopedia)hydrazine hīˈdrəzēnˌ [key], chemical compound, formula NH2NH2, m.p. 1.4℃, b.p. 113.5℃, specific gravity 1.011 at 15℃. It is very soluble in water and soluble in alcohol. At ordinary tempera...

anemone

(Encyclopedia)anemone ənĕmˈənē [key] or windflower, any of the perennial herbs, wild or cultivated, of the genus Anemone of the family Ranunculaceae (buttercup family). A rich legendary history has gained the ...

fungicide

(Encyclopedia)fungicide fŭnˈjəsīdˌ, fŭngˈgə– [key], any substance used to destroy fungi. Some fungi are extremely damaging to crops (see diseases of plants), and others cause diseases in humans and other ...

furnace

(Encyclopedia)furnace, enclosed space for the burning of fuel. There are many kinds of furnaces, the type depending upon the fuel and the use to which the heat produced within it is put. Most familiar are the furna...

Guam

(Encyclopedia)Guam gwäm [key], Chamorro Guåhan, officially Territory of Guam, the largest, most populous, and southernmost of the Mariana Islands (see also Northern Mariana Islands), an unincorporated territory o...

polychlorinated biphenyl

(Encyclopedia)polychlorinated biphenyl or PCB, any of a group of organic compounds originally widely used in industrial processes but later found to be dangerous environmental pollutants. Polychlorinated biphenyl i...