Columbia Encyclopedia

Search results

500 results found

Metchnikoff, Élie

(Encyclopedia)Metchnikoff, Élie ālēˈ mĕchˈnĭkôf [key], 1845–1916, Russian biologist. He studied in Russia and Germany, lectured at the Univ. of Odessa, and, after working with Pasteur in Paris, became (19...

medlar

(Encyclopedia)medlar mĕdˈlər [key], small deciduous tree (Mespilus germanica) of the family Rosaceae (rose family), native to Europe and Asia. It has luxuriant foliage and large white or pinkish flowers; in the ...

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...

Skou, Jens Christian

(Encyclopedia)Skou, Jens Christian, 1918–2018, Danish chemist, M.D. Univ. of Copenhagen, 1944, Ph.D. Univ. of Aarhus, 1954. Skou was on the faculty at the Univ. of Aarhus, Denmark, from 1947 until he retired in 1...

Reichstein, Tadeus

(Encyclopedia)Reichstein, Tadeus tädĕˈo͞osh rīkhˈshtīn [key], 1897–1996, Swiss organic chemist, b. Vlotslavsk, Russia (now Włocławek, Poland), educated at the technical school in Zürich, where he also t...

Szent-Gyorgyi, Albert von

(Encyclopedia)Szent-Gyorgyi, Albert von älˈbĕrt fən sĕntˌ-dyörˈdyĭ [key], 1893–1986, American biochemist, b. Hungary, M.D. Univ. of Budapest, 1917; Ph.D. Cambridge, 1927. After teaching at the universiti...

tautomer

(Encyclopedia)tautomer tôˈtəmər [key], one of two or more structural isomers that exist in equilibrium and are readily converted from one isomeric form to another. Of the various types of tautomerism that are p...

photoengraving

(Encyclopedia)photoengraving, photomechanical process in the graphic arts, used principally for reproducing illustrations. The subject is photographed, and the image is recorded on a sensitized metal plate, which i...

pectin

(Encyclopedia)pectin, any of a group of white, amorphous, complex carbohydrates that occur in ripe fruits and certain vegetables. Fruits rich in pectin are the peach, apple, currant, and plum. Protopectin, present ...

technetium

(Encyclopedia)technetium tĕknēˈshēəm [key] [Gr. technetos=artificial], artificially produced radioactive chemical element; symbol Tc; at. no. 43; mass no. of most stable isotope 98; m.p. 2,200℃; b.p. 4,877�...