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Berthelot, Pierre Eugène Marcelin

(Encyclopedia)Berthelot, Pierre Eugène Marcelin pyĕr ûzhĕnˈ märsəlăNˈ bĕrtəlōˈ [key], 1827–1907, French chemist. He was professor at the École Supérieure de Pharmacie (1859) and at the Collège de ...

loam

(Encyclopedia)loam, soil composed of sand, silt, clay, and organic matter in evenly mixed particles of various sizes. More fertile than sandy soils, loam is not stiff and tenacious like clay soils. Its porosity all...

Louis, Morris

(Encyclopedia)Louis, Morris, 1912–62, American painter, b. Baltimore. A practitioner of color-field painting, Louis was noted for soaking poured paint through unsized and often unstretched canvas. Prior to 1960 h...

mechanism

(Encyclopedia)mechanism, philosophical theory about the nature of organic systems, holding that organisms are machines in the sense that they are material systems. Mechanism seeks to explain biological processes, i...

ethyl

(Encyclopedia)ethyl ĕthˈəl [key], CH3CH2, organic free radical or alkyl group derived from ethane by removing one hydrogen atom. ...

prosthetic group

(Encyclopedia)prosthetic group, non-amino acid portions of certain protein molecules. The key part of the prosthetic group may be either organic (such as a vitamin) or inorganic (such as a metal) and is usually req...

celestite

(Encyclopedia)celestite sĕlˈəstĭn, –tīn [key], mineral appearing in blue-tinged or white orthorhombic crystals or in fibrous masses. The natural sulfate of strontium, SrSO4, it is important as a source of st...

cerussite

(Encyclopedia)cerussite sērˈəsīt [key], colorless to white or gray mineral, sometimes yellowish or greenish, transparent to opaque, very brittle, crystallizing in the orthorhombic system and occurring also in g...

matter

(Encyclopedia)matter, anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles. The atomic th...

waterfowl

(Encyclopedia)waterfowl, common term for members of the order Anseriformes, wild, aquatic, typically freshwater birds including ducks, geese, and screamers. In Great Britain the term is also used to designate speci...