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as a green image seen after viewing a red wafer lying on white paper. Called also ocular spectrum. Absorption spectrum, the spectrum of light which has passed through a medium capable of absorbing a portion of the rays. It is characterized by dark spaces, bands, or lines. -- Chemical spectrum, a spectrum of rays cons…

d chromatic aberration, when due to different refrangibilities of the colored rays of the spectrum, those of each color having a distinct focus.

ent for measuring minute quantities of radiant heat, especially in different parts of the spectrum; -- called also actinic balance, thermic balance. S. P. Langley.

metal found in mineral water; -- so called from the two characteristic blue lines in its spectrum. It was the first element discovered by spectrum analysis, and is the most strongly basic and electro-positive substance known. Symbol Cs. Atomic weight 132.6.

gaseous substance forming the solar corona, characterized by a green line in the coronal spectrum.

ed diffraction. Whewell. Diffraction grating. (Optics) See under Grating. -- Diffraction spectrum. (Optics) See under Spectrum.

due to the fact that the axial angle has different values for the different colors of the spectrum.

the wind and filling away again on the same tack. -- False vampire (Zoöl.), the Vampyrus spectrum of South America, formerly erroneously supposed to have blood-sucking habits; -- called also vampire, and ghost vampire. The genuine blood-sucking bats belong to the genera Desmodus and Diphylla. See Vampire. -- False wi…

Decorated with flutes; channeled; grooved; as, a fluted column; a fluted ruffle; a fluted spectrum.

The lines of the spectrun; especially and properly, the dark lines of the solar spectrum, so called because first accurately observed and interpreted by Fraunhofer, a German physicist.

A supposed rare metallic element, with a characteristic spectrum, found associated with yttrium and other rare metals. Its individuality and properties have not yet been determined.

Having the color of grass when fresh and growing; resembling that color of the solar spectrum which is between the yellow and the blue; verdant; emerald.

ee under Food. -- Heat rays, a term formerly applied to the rays near the red end of the spectrum, whether within or beyond the visible spectrum. -- Heat weight (Mech.), the product of any quantity of heat by the mechanical equivalent of heat divided by the absolute temperature; -- called also thermodynamic function,…

rare metallic element, discovered in certain ores of zinc, by means of its characteristic spectrum of two indigo blue lines; hence, its name. In appearance it resembles zinc, being white or lead gray, soft, malleable and easily fusible, but in its chemical relation it resembles aluminium or gallium. Symbol In. Atomic w…

Lying outside the visible spectrum at its red end; -- said of rays less refrangible than the extreme red rays.

A spectroscope arranged for attachment to a microscope, for observation of the spectrum of light from minute portions of any substance.

ects. Obscure rays (Opt.), those rays which are not luminous or visible, and which in the spectrum are beyond the limits of the visible portion.

A vacuum tube, used in spectrum analysis, in which the part through which the discharge takes place is a capillary tube, thus producing intense incandescence of the contained gases.

a prism for viewing a distant object and the compass card at the same time. -- Prismatic spectrum (Opt.), the spectrum produced by the passage of light through a prism.

us process from pitchblende. Its compounds color flames carmine and give a characteristic spectrum. It resembles barium chemically. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, an…