THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JANUARY 1892. 



I. On Reflexion from Liquid Surfaces in the Neighbourhood of 

 the Polarizing Angle. By Lord Rayleigh, Sec. R.S.* 



BY the experiments of Jamin and others it has been 

 abundantly proyed that in the neighbourhood of the 

 polarizing angle the reflexion of light from ordinary trans- 

 parent liquids and solids deviates sensibly from the laws of 

 Fresnel, according to which the reflexion of light polarized 

 perpendicularly to the plane of incidence should vanish when 

 the incidence takes place at the Brewsterian angle. It is 

 found, on the contrary, that in most cases the residual light is 

 sensible at all angles, and that the change of phase by 180°, 

 which, according to FresnePs formula, should occur suddenly, 

 in reality enters by degrees, so that in general plane-polarized 

 light acquires after reflexion a certain amount of ellipticity. 

 Although Jamin describes the non-evanescence at the polar- 

 izing angle and the ellipticity in its neighbourhood as " deux 

 ordres de phenomenes de nature differente," it is clear that 

 they are really inseparable parts of one phenomenon. If we 

 suppose the incident light polarized perpendicularly to the 

 plane of incidence to be given, the vibration which determines 

 the reflected light at various angles may be represented in 

 amplitude and phase by the situation of points relatively to 

 an origin and coordinate axes. Thus, according to Fresnel's 

 formula, the locus of these points is the axis of abscissre X X' 



* Communicated by the Author. 

 Phil. Mag. S. 5. Vol. 33. No. 200. Jan, 1892. B 



