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chemical bond

(Encyclopedia)chemical bond, mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the for...

atomism

(Encyclopedia)atomism, philosophic concept of the nature of the universe, holding that the universe is composed of invisible, indestructible material particles. The theory was first advanced in the 5th cent. b.c. b...

Webster, Pelatiah

(Encyclopedia)Webster, Pelatiah, 1726–95, American writer, b. Lebanon, Conn., grad. Yale, 1746. A Philadelphia businessman, he is remembered for his advocacy in his Dissertation of the Political Union and Constit...

Sanctorius

(Encyclopedia)Sanctorius săngktôrˈēəs [key], Ital. Santorio, 1561–1636, Italian physiologist. He was a professor at Padua (1611–24). By his quantitative experiments in temperature, respiration, and weight,...

grouper

(Encyclopedia)grouper, common name for a large carnivorous member of the family Serranidae (sea bass family), abundant in tropical and subtropical seas and highly valued as food fish. There are several genera, nota...

titration

(Encyclopedia)titration tītrāˈshən [key], gradual addition of an acidic solution to a basic solution or vice versa (see acids and bases); titrations are used to determine the concentration of acids or bases in ...

de Gennes, Pierre-Gilles

(Encyclopedia)de Gennes, Pierre-Gilles, 1932–2007, French physicist, Ph.D. Center for Nuclear Studies at Saclay, France, 1958. He was a professor at the Univ. of Paris, Orsay, from 1961 to 1971, when he joined th...

Clausius, Rudolf Julius Emanuel

(Encyclopedia)Clausius, Rudolf Julius Emanuel ro͞oˈdôlf yo͞oˈlyo͝os āmäˈno͞oĕl klouˈzēo͝os [key], 1822–88, German mathematical physicist. A pioneer in the science of thermodynamics, he introduced th...

Hilleman, Maurice Ralph

(Encyclopedia)Hilleman, Maurice Ralph, 1919–2005, American microbiologist, regarded as the father of modern vaccinology, b. Miles City, Mont., Ph.D Univ. of Chicago, 1941. He joined E. R. Squibb and Sons in 1944,...

pathology

(Encyclopedia)pathology, study of the cause of disease and the modifications in cellular function and changes in cellular structure produced in any cell, organ, or part of the body by disease. The changes in tissue...