Columbia Encyclopedia

Search results

500 results found

platinum

(Encyclopedia)platinum plătˈənəm [key], metallic chemical element; symbol Pt; at. no. 78; at. wt. 195.084; m.p. 1,772℃; b.p. 3,827±100℃; sp. gr. 21.45 at 20℃; valence +2 or +4. Pure platinum is a malleab...

Hopkins, Sir Frederick Gowland

(Encyclopedia)Hopkins, Sir Frederick Gowland, 1861–1947, English biochemist, educated at Cambridge and the Univ. of London. He was professor of biochemistry at Cambridge (1914–43). Among his contributions were ...

gilding

(Encyclopedia)gilding, process of applying a thin layer of real or imitation gold to a surface. The process is employed on wood, metal, ivory, leather, paper, glass, porcelain, and fabrics and is used to embellish ...

nux vomica

(Encyclopedia)nux vomica nŭks vŏmˈəkə [key], bitter-tasting drug obtained from the poisonous seeds of Strychnos nux-vomica, a tree that grows in Sri Lanka, India, and N Australia. The dried seeds contain stryc...

nitro group

(Encyclopedia)nitro group, in chemistry, functional group that consists of a nitrogen atom joined to two oxygen atoms. Compounds that contain a nitro group, e.g., picric acid and trinitrotoluene (TNT), are called n...

Lister, Joseph Lister, 1st Baron

(Encyclopedia)Lister, Joseph Lister, 1st Baron, 1827–1912, English surgeon, educated at University College, London. He brought to surgery the principle of antisepsis, an outgrowth of Pasteur's theory that bacteri...

Wöhler, Friedrich

(Encyclopedia)Wöhler, Friedrich frēˈdrĭkh vöˈlər [key], 1800–1882, German chemist. He studied under the German chemist Leopold Gmelin and J. J. Berzelius, a Swedish chemist, and in 1836 was appointed profe...

stearin

(Encyclopedia)stearin stērˈĭn [key], fat that is the triglyceride of stearic acid, CH3(CH2)16CO2H, i.e., the tristearate ester of glycerol. It is a white crystalline solid at ordinary temperatures and is insolub...

bayberry

(Encyclopedia)bayberry, common name for the Myricaceae, a family of trees and shrubs with aromatic foliage, found chiefly in temperate and subtropical regions. The waxy gray “berries” of the North American wild...

Ramsay, Sir William

(Encyclopedia)Ramsay, Sir William, 1852–1916, Scottish chemist. He was professor of chemistry at University College, Bristol (1880–87), and at University College, London (1887–1912). In his early experiments ...