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soil

(Encyclopedia)soil, surface layer of the earth, composed of fine rock material disintegrated by geological processes; and humus, the organic remains of decomposed vegetation. In agriculture, soil is the medium that...

bivalve

(Encyclopedia)CE5 Internal anatomy of a clam, Anodonta, representative mollusk of the class Pelecypoda (the bivalves) bivalve, aquatic mollusk of the class Pelecypoda (“hatchet-foot”) or Bivalvia, with a la...

druids

(Encyclopedia)druids dro͞oˈĭdz [key], priests of ancient Celtic Britain, Ireland, and Gaul and probably of all ancient Celtic peoples, known to have existed at least since the 3d cent. BC. Information about them...

chiton

(Encyclopedia)CE5 A. Dorsal view of a chiton, representative mollusk of the class Amphineura B. Internal anatomy of a chiton chiton kīˈtən [key], common name for rock-clinging marine mollusks of the class Po...

Interior, United States Department of the

(Encyclopedia)Interior, United States Department of the, federal executive department established in 1849, delegated custodian of U.S. natural resources, and whose head, the Secretary of the Interior, has cabinet r...

hydrolysis

(Encyclopedia)hydrolysis hīdrŏlˈĭsĭs [key], chemical reaction of a compound with water, usually resulting in the formation of one or more new compounds. The most common hydrolysis occurs when a salt of a weak ...

histidine

(Encyclopedia)CE5 histidine hĭsˈtĭdēn [key], organic compound, one of the 22 α-amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. Histidine is the direct pr...

Fredericksburg

(Encyclopedia)Fredericksburg. 1 Town (2020 pop. 10,875), Gillespie co., S central Texas, in the Texas Hill Country near the Pedernales River; inc. 1928. Located in an...

Gram's stain

(Encyclopedia)Gram's stain, laboratory staining technique that distinguishes between two groups of bacteria by the identification of differences in the structure of their cell walls. The Gram stain, named after its...

gelatin

(Encyclopedia)gelatin or animal jelly, foodstuff obtained from connective tissue (found in hoofs, bones, tendons, ligaments, and cartilage) of vertebrate animals by the action of boiling water or dilute acid. It is...