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Swammerdam, Jan

(Encyclopedia)Swammerdam, Jan yän väˈmərdäm [key], 1637–80, Dutch naturalist. He was a pioneer in the use of the microscope. Before he turned to religious contemplation his chief interest was the study of in...

swim bladder

(Encyclopedia)swim bladder, large, thin-walled sac in some fishes that may function in several ways, e.g., as a buoyant float, a sound producer and receptor, and a respiratory organ. The swim bladder, or air bladde...

Blumberg, Baruch Samuel

(Encyclopedia)Blumberg, Baruch Samuel, 1925–2011, American biochemist and medical anthropologist, b. Brooklyn, N.Y., B.S. Union College, Schenectady, N.Y., 1946, M.D. Columbia, 1951, Ph.D. Oxford, 1957. From 1957...

metamorphism

(Encyclopedia)metamorphism, in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combin...

transmission

(Encyclopedia)transmission, in automobiles, system of parts connecting the engine to the wheels. Suitable torque, or turning force, is generated by the engine only within a narrow range of engine speeds, i.e., rate...

Hasan

(Encyclopedia)Hasan häsänˈ [key], c.625–c.669; son of Ali and Fatima (daughter of Muhammad the Prophet). When Ali was killed in 661, Hasan became caliph, but he was not strong enough to withstand the threat of...

homogenization

(Encyclopedia)homogenization həmŏjˌənəzāˈshən [key], process in which a mixture is made uniform throughout. Generally this procedure involves reducing the size of the particles of one component of the mixtu...

harpoon

(Encyclopedia)harpoon härpo͞onˈ [key], weapon used for spearing whales and large fish. The early type was a flat triangular piece of metal with barbed edges and a socket for attaching a wooden handle, to the end...

amphictyony

(Encyclopedia)amphictyony ămfĭkˈtēōˌnē, –ŏˌnē, –ənēˌ [key], in ancient Greece, a league connected with maintaining a temple or shrine. There were a number of these, but by far the most important wa...

flint, mineral

(Encyclopedia)flint, variety of quartz that commonly occurs in rounded nodules and whose crystal structure is not visible to the naked eye. Flint is dark gray, smoky brown, or black in color; pale gray flint is cal...