Page:Collected Physical Papers.djvu/13

page radiation and induced conductivity variation—Fatigue and reversal in Ag and Fe3O4 receivers under continued radiation—Electromotive response of Mg receiver under electric radiation—Electromotive response of AgBr cell under light—Fatigue and reversal exhibited by AgBr cell under continued action of light •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •

163

XV

ON THE SIMILARITIES BETWEEN RADIATION AND MECHANICAL STRAINS

Conductivity variation under mechanical strain—Variation of resistance of surface contacts under electric radiation—Electromotive variation under photic and mechanical stimulation—The Strain Cell—Response to torsional stimulation—Self-recovery—Response independent of direction of torsion—Response to single stimulation—Increasing response under increasing amplitude of torsional vibration—Summated effect of stimuli—Opposite sign of response under subminimal stimulation—Reversal under continuous stimulation—Molecular response common to electric radiation, light and mechanical vibration—Stimulation by light balanced by mechanical stimulation •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •

192

(Proc. Roy. Soc. June, 1901.)

XVI

ON THE STRAIN THEORY OF PHOTOGRAPHIC ACTION

Photographic effect essentially due to molecular action—Difficulty in detection of minute induced change—Primary and secondary reactions—Chemical and physical theories—Relapse of image due to self-recovery—Permanence of after-effect by overstrain—Curve of electromotive variation under light—Preliminary negative twitch preceding normal action—Recurrent reversals under mechanical stimulation—Photo-chemical induction—Effect of intermittent and of continuous light—Photographic effect modified by time-rate—Recurrent reversals under light—Pressure image and inductoscripts •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •          •

208

(Proc. Roy. Soc. June, 1901.)

XVII

ON THE CHANGE OF CONDUCTIVITY OF METALLIC PARTICLES UNDER CYCLIC ELECTROMOTIVE VARIATION

Conductivity variation under rapid electromotive variation due to electric radiation—The Conductivity Recorder—Characteristic curve of a single-point Iron Receiver—Effect of intensity of currents in modification of the characteristic curve—The time-lag—Characteristic curve of a mass of iron-filings—Curve of Cyclic Variation exhibiting hysteresis—Response of self-recovering receiver