Search the Dictionary

bliquely a medium of a different density from that through which it has previously moved. Refraction out of the rarer medium into the denser, is made towards the perpendicular. Sir I. Newton.

rved after the summits have passed into shadow, supposed to be due to a curving downward (refraction) of the light rays from the west resulting from the cooling of the air.

Produced by the refraction of light, as seen through water; as, anaclastic curves.

That part of optics which treats of the refraction of light; -- commonly called dioptrics. Encyc. Brit.

to the center of the eye. -- For Angles of commutation, draught, incidence, reflection, refraction, position, repose, fraction, see Commutation, Draught, Incidence, Reflection, Refraction, etc.

An anomalous state of refraction caused by the absence of the crystalline lens, as after operations for cataract. The remedy is the use of powerful convex lenses. Dunglison.

ity on which another quantity in a table depends; as, the altitude is the argument of the refraction.

ic axis of a crystal, the direction in which a ray of transmitted light suffers no double refraction. All crystals, not of the isometric system, are either uniaxial or biaxial. -- Optic axis, Visual axis (Opt.), the straight line passing through the center of the pupil, and perpendicular to the surface of the eye. --…

Pertaining to, produced by, or involving, both the reflection and refraction of light; as, a catadioptric light. Hutton.

surfaces are called catacaustic when formed by reflection, and diacaustic when formed by refraction.

Not parallel; lying or falling athwart; transverse; oblique; intersecting. The cross refraction of the second prism. Sir I. Newton.

Pertaining to, or possessing the properties of, a species of caustic curves formed by refraction. See Caustic surface, under Caustic.

, the parts of which do not correspond in size or proportion; difform leaves. The unequal refractions of difform rays. Sir I. Newton.

Of or pertaining to dioptrics; assisting vision by means of the refraction of light; refractive; as, the dioptric system; a dioptric glass or telescope. "Dioptrical principles." Nichol. Dioptric curve (Geom.), a Cartesian oval. See under Cartesian.

The science of the refraction of light; that part of geometrical optics which treats of the laws of the refraction of light in passing from one medium into another, or through different mediums, as air, water, or glass, and esp. through different lenses; -- distinguished from catoptrics, which refers to reflected light…

er (Opt.), the relative effect of a material in separating the different rays of light by refraction, as when the substance is formed into a prism. -- Dis*pers"ive*ness, n.

ouble point. -- Double quarrel. (Eccl. Law) See Duplex querela, under Duplex. -- Double refraction. (Opt.) See Refraction. -- Double salt. (Chem.) (a) A mixed salt of any polybasic acid which has been saturated by different bases or basic radicals, as the double carbonate of sodium and potassium, NaKCO3.6H2O. (b) A…

surface of an ellipsoid (see Pedal); a surface used in explaining the phenomena of double refraction and their relation to the elastic force of the luminous ether in crystalline media.

e, usually prismatically colored, round the sun or moon, and supposed to be caused by the refraction of light through crystals of ice in the atmosphere. Connected with halos there are often white bands, crosses, or arches, resulting from the same atmospheric conditions.

ed in Iceland. It is used for the prisms of the polariscope, because of its strong double refraction. Cf. Calcite.