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etching

(Encyclopedia)etching, the art of engraving with acid on metal; also the print taken from the metal plate so engraved. In hard-ground etching the plate, usually of copper or zinc, is given a thin coating or ground ...

paramecium

(Encyclopedia)paramecium parəmēˈsĭəm [key], unicellular organism of the genus Paramecium, of the ciliate phylum Ciliophora found in freshwater throughout the world. Like other protozoans, paramecia, previously...

hydrogen sulfide

(Encyclopedia)hydrogen sulfide, chemical compound, H2S, a colorless, extremely poisonous gas that has a very disagreeable odor, much like that of rotten eggs. It is slightly soluble in water and is soluble in carbo...

mordant

(Encyclopedia)mordant môrˈdənt [key] [Fr.,=biting], substance used in dyeing to fix certain dyes (mordant dyes) in cloth. Either the mordant (if it is colloidal) or a colloid produced by the mordant adheres to t...

vitamin

(Encyclopedia)vitamin, group of organic substances that are required in the diet of humans and animals for normal growth, maintenance of life, and normal reproduction. Vitamins act as catalysts; very often either t...

LSD

(Encyclopedia)LSD or lysergic acid diethylamide līˌsûrˈjĭk, dīˌĕthˈələmĭd, dīˌĕthəlămˈĭd [key], alkaloid synthesized from lysergic acid, which is found in the fungus ergot (Claviceps purpurea). I...

Kornberg, Roger David

(Encyclopedia)Kornberg, Roger David, 1947–, American biochemist, b. St. Louis, Mo., Ph.D. Stanford, 1972; son of Arthur Kornberg. Kornberg held academic posts at Cambridge (1972–76) and Harvard (1976–78) befo...

Smith, Michael

(Encyclopedia)Smith, Michael, 1932–2000, British-born Canadian biochemist, Ph.D. Univ. of Manchester, 1956. Smith was a researcher at the Univ. of British Columbia from 1961 until his death in 2000. He shared the...

cyclamate

(Encyclopedia)cyclamate sīˌkləmātˌ, –mət [key], any member of a group of salts of cyclamic acid (cyclohexanesulfamic acid). The sodium and calcium salts were commonly used as artificial sweeteners until 196...

fulminate

(Encyclopedia)fulminate fŭlˈmĭnāt [key], any salt of fulminic acid, HONC, a highly unstable compound known only in solution. The term is most commonly applied to the explosive mercury (II) fulminate, also calle...