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CONTENTS
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Selective transparency for polarised electric ray—Double absorption exhibited by Nemalite, Chrysotile, Satin spar and Epidote—Relation between double absorption and double conductivity—Selective transparency exhibited by ordinary books—The book form of Polariser and Analyser • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
71 |
(Proc. Roy. Soc. January 1897.)
Production of mechanical waves—Oscillatory electric discharge—Failure of oscillatory discharge by disintegrating action of sparks remedied by platinum coating—Electric radiation from a single spark—Magnetic disturbance screened by soft-iron cover—Stray radiation and reflection from the body of the observer—Advantages of short electric waves—Spiral spring and single contact receivers—Enhancement of sensibility by adjustment of E. M. F.—Nickel, aluminium and magnesium receivers—Portable radiation apparatus—Selective absorption—Transparency of liquid air—Varification of the laws of reflection—Opacity due to multiple reflection and refraction—Total reflection by right-angled glass prism—Determination of index of refraction by method of total reflection—Double refraction of the electric ray by crystals belonging to Tetragonal, Orthorhombic, Hexagonal, Monoclinic and Triclinic systems—Double refraction by strained dielectric—Phenomenon of double absorption—Electric tourmalines—Anisotropic conductivity of polarising substances—'Bradshaw' as a polariser • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
77 |
The book form of Polariser and Analyser—No polarisation by a jute-bundle when its length is parallel to the electric ray—Rotation of plane of polarisation by twisted jute-bundle—Rotating elements, positive and negative—Electro-optic analogue of dextrose and levulose—Neutralisation by mixture of equal numbers of positive and negative elements • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
102 |
Production of dark cross by salicine interposed between crossed Nicols—Production of cross in the dark field of electric radiation by interposition of circular |
