Columbia Encyclopedia

Search results

500 results found

Abu al-Abbas as-Saffah

(Encyclopedia)Abu al-Abbas as-Saffah äˈbo͞o äl-äbäsˈ äs-säfäˈ [key], d. 754, 1st Abbasid caliph (749–54). Raised to the caliphate by the armed might of Abu Muslim, he took the reign name as-Saffah [she...

Cohnheim, Julius

(Encyclopedia)Cohnheim, Julius yo͞oˈlyo͝os kōnˈhīm [key], 1839–84, German experimental histologist and pathologist. In a relatively brief life Cohnheim made a series of remarkable contributions to the rapid...

emetic

(Encyclopedia)emetic əmĕtˈĭk [key], substance that produces vomiting. Direct, or gastric, emetics, which act directly on the stomach, include syrup of ipecac, sulfate of zinc or copper, alum, ammonium carbonate...

Schleicher, Kurt von

(Encyclopedia)Schleicher, Kurt von, 1882–1934, German general. A leading Reichswehr (army) figure after World War I, Schleicher wielded great power in the years before Adolf Hitler came to power (1933). He was wa...

Agre, Peter Courtland

(Encyclopedia)Agre, Peter Courtland, 1949–, American molecular biologist, b. Northfield, Minn., M.D. Johns Hopkins, 1974. From 1981 to 2005, Agre taught at Johns Hopkins in the departments of medicine and cell bi...

Caesalpinus, Andreas

(Encyclopedia)Caesalpinus, Andreas ändrĕˈä chāzälpēˈnō [key], 1519–1603, Italian botanist and physiologist. He was physician to Pope Clement VIII. He described, in part and as a theory only, the circulat...

lamprey

(Encyclopedia)lamprey, name for several primitive marine and freshwater jawless fishes of the order Petromyzontiformes. As in the other jawless fish, the hagfish, the adult lamprey retains the notochord, the suppor...

lungs

(Encyclopedia)lungs, elastic organs used for breathing in vertebrate animals, excluding most fish, which use gills, and a few amphibian species that respire through the skin. The word is sometimes applied to the re...

neoplasm

(Encyclopedia)neoplasm or tumor, tissue composed of cells that grow in an abnormal way. Normal tissue is growth-limited, i.e., cell reproduction is equal to cell death. Feedback controls limit cell division after a...

specific gravity

(Encyclopedia)specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the t...