Columbia Encyclopedia

(Encyclopedia) Haldane, John Scott, 1860–1936, British scientist, b. Edinburgh; father of John Burdon Sanderson Haldane. He made many important contributions to mine safety, investigating principally the action of...

(Encyclopedia) fermentation, process by which the living cell is able to obtain energy through the breakdown of glucose and other simple sugar molecules without requiring oxygen. Fermentation is achieved by somewhat...

(Encyclopedia) mercaptan thīˈōl [key], any of a class of organic compounds containing the group –SH bonded to a carbon atom. The volatile low-molecular-weight mercaptans have disagreeable odors. Mercaptans are ...

(Encyclopedia) anhydride ănhīˈdrīd, –drĭd [key] [Gr.,=without water], chemical compound formed by removing water, H2O, from another compound; the anhydride can also react with water to form the original compo...

(Encyclopedia) Urey, Harold Clayton yo͝orˈē [key], 1893–1981, American chemist, b. Walkerton, Ind., grad. Univ. of Montana (B.S., 1917), Ph.D. Univ. of California, 1923. He taught at Johns Hopkins (1924–29), ...

(Encyclopedia) Liebig, Justus, Baron von yo͝osˈto͝os bärônˈ fən lēˈbĭkh [key], 1803–73, German chemist. As professor at Giessen (1824–52), he was among the first to establish a chemical teaching labora...

(Encyclopedia) excretion, process of eliminating from an organism waste products of metabolism and other materials that are of no use. It is an essential process in all forms of life. In one-celled organisms wastes ...

(Encyclopedia) gallic acid or 3,4,5-trihydroxybenzoic acid trīˌhīdrŏkˈsēbĕnzōˈĭk [key], C6H2(OH)3CO2H, colorless crystalline organic acid found in gallnuts, sumach, tea leaves, oak bark, and many other pla...

(Encyclopedia) Leipzig līpˈtsĭkh [key], city (1994 pop. 490,850), Saxony, E central Germany, at the confluence of the Pleisse, White Elster, and Parthe rivers. Originally a Slavic settlement called Lipsk, Leipz...

(Encyclopedia) chlorofluorocarbons klōrˌəflo͝orˈəkärˌbənz, klôrˌ– [key] (CFCs), organic compounds that contain carbon, chlorine, and fluorine atoms. CFCs are highly effective refrigerants that were deve...