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The doctrine of refracted sound; diacoustics.

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

A unit employed by oculists in numbering glasses according to the metric system; a refractive power equal to that of a glass whose principal focal distance is one meter.

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…

One of a species of coccoliths, having an oval discoidal body, with a thick strongly refracting rim, and a thinner central portion. One of them measures about

One of the dark particles forming the doubly refracting disks of muscle fibers.

cting or refusing to obey; omitting to do what is commanded, or doing what is prohibited; refractory; not observant of duty or rules prescribed by authority; -- applied to persons and acts. This disobedient spirit in the colonies. Burke. Disobedient unto the word of the Lord. 1 Kings xiii. 26.

ws, etc.); to transgress the commands of (one in authority); to violate, as an order; as, refractory children disobey their parents; men disobey their Maker and the laws. Not to disobey her lord's behest. Tennyson.

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.

concealment, or of rising into view; sudden uprisal or appearance. The white color of all refracted light, at its very first emergence . . . is compounded of various colors. Sir I. Newton. When from the deep thy bright emergence sprung. H. Brooke.

That refractive condition of the eye in which the rays of light are all brought accurately and without undue effort to a focus upon the retina; -- opposed to hypermetropia, myopia, an astigmatism.

- Fire box, the chamber of a furnace, steam boiler, etc., for the fire. -- Fire brick, a refractory brick, capable of sustaining intense heat without fusion, usually made of fire clay or of siliceous material, with some cementing substance, and used for lining fire boxes, etc. -- Fire brigade, an organized body of me…

A refractory material consisting of crushed or ground siliceous stone, mixed with fire clay; -- used for lining Bessemer converters; also used for macadamizing roads.

Not wild, turbulent, or refractory; quiet and docile; tame; peaceable; as, a gentle horse.

abolition of sight, with a diminution of transparency, a bluish or greenish tinge of the refracting media of the eye, and a hard inelastic condition of the eyeball, with marked increase of tension within the eyeball.

Wild or intractable; disposed to break away from duty; untamed; as, a haggard or refractory hawk. [Obs.] Shak

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.