CAUSTIC; CAUSTICAL a.
he ray of light, reflected or refracted by another curve, are tangents, the reflecting or refracting curve and the luminous point being in one plane. -- Caustic lime. See under Lime. -- Caustic potash, Caustic soda (Chem.), the solid hydroxides potash, KOH, and soda, NaOH, or solutions of the same. -- Caustic silver…
POSITIVE a.
gative, and said of metals, bases, and basic radicals. Positive crystals (Opt.), a doubly refracting crystal in which the index of refraction for the extraordinary ray is greater than for the ordinary ray, and the former is refracted nearer to the axis than the latter, as quartz and ice; -- opposed to negative crystal,…
PRISM n.
rown glass, the difference of dispersive power being compensated by giving them different refracting angles, so that, when placed together so as to have opposite relative positions, a ray of light passed through them is refracted or bent into a new position, but is free from color. -- Nicol's prism, Nicol prism. Etym:…
RANGE n.
ion, -- usually measured and designated by the strength of the lens which if added to the refracting media of the eye would cause the rays from the near point to appear as if they came from the far point. -- Range finder (Gunnery), an instrument, or apparatus, variously constructed, for ascertaining the distance of an…