| glass-sponge | <zoology> A siliceous sponge, of the genus Hyalonema, and allied genera; so called from their glassy fibres or spicules. Synonym: vitreous sponge. See Glass-rope, and Euplectella. Source: Websters Dictionary (01 Mar 1998) |
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| vita glass | A specially prepared glass that is transparent to ultraviolet rays of the spectrum. (05 Mar 2000) |
| ground-glass pattern | Radiographic or CT appearance of hazy opacity which fails to obscure pulmonary vascular markings. (05 Mar 2000) |
| water glass | <chemistry> See Soluble glass, under Glass. Source: Websters Dictionary (01 Mar 1998) |
| Wood's glass | A glass containing nickel oxide, used in Wood's lamp. (05 Mar 2000) |
| cover glass | A thin glass disk or plate covering an object examined under the microscope. Synonym: coverslip. (05 Mar 2000) |
| Crookes' glass | A spectacle lens combined with metallic oxides to absorb ultraviolet or infrared rays. (05 Mar 2000) |
| crown glass | A compound of lime, potash, alumina, and silica; commonly used in lenses; has a low dispersion (52.2) relative to index of refraction (1.523). (05 Mar 2000) |
| cupping glass | A glass vessel, from which the air has been exhausted by heat or a special suction apparatus, formerly applied to the skin in order to draw blood to the surface. See: cupping, cup. Synonym: cup. (05 Mar 2000) |
| half-glass spectacles | Spectacles, used for reading, in which the upper portion of the lenses are removed. Synonym: clerical spectacles, pantoscopic spectacles, pulpit spectacles. (05 Mar 2000) |
| soluble glass | A silicate of potassium or sodium, soluble in hot water but solid at ordinary temperatures; used for fixed dressings. Synonym: water glass. (05 Mar 2000) |
| quartz glass | A transparent, colourless crystal, made by fusing pure quartz sand, which transmits ultraviolet light. (05 Mar 2000) |
| object glass | 1. <psychology> Perceptible to the external senses. 2. <ophthalmology> The lens or system of lenses in a microscope (or telescope) that is nearest to the object under examination. Origin: L. Objectivus (18 Nov 1997) |
| opera-glass hand | A deformity of the hand seen in chronic absorptive arthritis, the fingers and wrists being shortened and the covering skin wrinkled into transverse folds; the phalanges appear to be retracted into one another like an opera glass or miniature telescope. Synonym: main en lorgnette. (05 Mar 2000) |
| three-glass test | The bladder is emptied by passing urine into a series of 3-ounce test tubes, and the contents of the first and the last are examined; the first tube contains the washings from the anterior urethra, the second, material from the bladder, and the last, material from the posterior urethra, prostate, and seminal vesicles. Synonym: Valentine's test. (05 Mar 2000) |