Columbia Encyclopedia

Search results

500 results found

Mar, John Erskine, 1st (or 6th) earl of

(Encyclopedia)Mar, John Erskine, 1st (or 6th) earl of, d. 1572, regent of Scotland. As Lord Erskine he was keeper of Edinburgh and Stirling castles, a source of much political strength. In the struggle between the ...

Mar, John Erskine, 6th (or 11th) earl of

(Encyclopedia)Mar, John Erskine, 6th (or 11th) earl of, 1675–1732, Scottish nobleman, leader of the Jacobites. He was nicknamed “Bobbing John,” probably because of his political vacillation. He succeeded his ...

Nunavut

(Encyclopedia)Nunavut no͞oˈnəvo͞otˌ [key] [Inuktituk,=our land], territory (2001 pop. 26,745), 772,260 sq mi (2,000,671 sq km), NE Canada. The capital and largest town is Iqaluit on Baffin Island at Frobisher ...

nitrogen cycle

(Encyclopedia)CE5 Nitrogen cycle nitrogen cycle, the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen...

ribbon grass

(Encyclopedia)ribbon grass, ornamental perennial grass (Phalaris arundinacea var. picta), a variety of the reed canary grass. It has green leaves striped with white and is often cultivated in gardens; it is also kn...

ester

(Encyclopedia)CE5 Esters ester, any one of a group of organic compounds with general formula RCO2R′ (where R and R′ are alkyl groups or aryl groups) that are formed by the reaction between an alcohol and an...

gram-molecular weight

(Encyclopedia)gram-molecular weight, amount of a molecular substance whose weight, in grams, is numerically equal to the molecular weight of that substance. For example, one gram-molecular weight of molecular oxyge...

sulfide

(Encyclopedia)sulfide, chemical compound containing sulfur and one other element or sulfur and a radical. Sulfides may be salts or esters of hydrogen sulfide, H2S, or may be formed directly, e.g., by heating a meta...

leaching

(Encyclopedia)leaching, method of extraction in which a solvent is passed through a mixture to remove some desired substance from it. A simple example is the passage of boiling water through ground coffee to dissol...

gramicidin

(Encyclopedia)gramicidin grămˌĭsīdˈən [key], antibiotic obtained from the bacterial species Bacillus brevis, which is found in soil. Gramicidin is particularly effective against gram-positive bacteria (see Gr...