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galvanizing

(Encyclopedia)galvanizing, process of coating a metal, usually iron or steel, with a protective covering of zinc. Galvanized iron is prepared either by dipping iron, from which rust has been removed by the action o...

fluorite

(Encyclopedia)fluorite flo͞oˈərspär [key], mineral appearing in various colors, e.g., green, yellow-brown, rose, and red. Chemically, it is calcium fluoride, CaF2. Its crystals, commonly cubic, are transparent ...

aquatint

(Encyclopedia)aquatint äˈkwətĭntˌ [key], etching technique. The plate is covered with a porous ground, or resist, through which acid bites many tiny pockmarks in the metal. If an area is to be completely white...

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 ...

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...

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 ...

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...

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...

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...