Columbia Encyclopedia

Search results

500 results found

cheese

(Encyclopedia)cheese, food known from ancient times and consisting of the curd of milk separated from the whey. The numerous cheeses (often named for their place of origin) depend for their distinctive qualities ...

penicillin

(Encyclopedia)penicillin, any of a group of chemically similar substances obtained from molds of the genus Penicillium that were the first antibiotic agents to be used successfully in the treatment of bacterial inf...

silver

(Encyclopedia)silver, metallic chemical element; symbol Ag [Lat. argentum]; at. no. 47; at. wt. 107.8682; m.p. 961.93℃; b.p. 2,212℃; sp. gr. 10.5 at 20℃; valence +1 or +2. Pure silver is nearly white, lustrou...

reproduction

(Encyclopedia)CE5 Examples of asexual reproduction reproduction, capacity of all living systems to give rise to new systems similar to themselves. The term reproduction may refer to this power of self-duplicati...

dissociation

(Encyclopedia)dissociation, in chemistry, separation of a substance into atoms or ions. Thermal dissociation occurs at high temperatures. For example, hydrogen molecules (H2) dissociate into atoms (H) at very high ...

cresol

(Encyclopedia)cresol krēˈsōl [key], CH3C6H4OH, any one of three aromatic alcohols present in coal tar. The three compounds are structural isomers; they may be thought of as hydroxy derivatives of toluene or as m...

Crick, Francis Harry Compton

(Encyclopedia)Crick, Francis Harry Compton, 1916–2004, English scientist, grad. University College, London, and Caius College, Cambridge. Crick was trained as a physicist, and from 1940 to 1947 he served as a sci...

glucose

(Encyclopedia)glucose, dextrose, or grape sugar, monosaccharide sugar with the empirical formula C6H12O6 . This carbohydrate occurs in the sap of most plants and in the juice of grapes and other fruits. Glucose ...

Goodyear, Charles

(Encyclopedia)Goodyear, Charles, 1800–1860, American inventor, b. New Haven, Conn., originator of vulcanized rubber. He failed in his earlier business ventures and was in jail for debt when he began his experimen...

formaldehyde

(Encyclopedia)formaldehyde fôrmălˈdəhīdˌ [key], HCHO, the simplest aldehyde. It melts at −92℃, boils at −21℃, and is soluble in water, alcohol, and ether; at STP, it is a flammable, poisonous, colorle...