On Polarization of Light by Refraction. 



235 



It is obvious from a consideration of the principle of the formula 

 for reflected light, that the quantity of polarized light is nothing at 0° 

 because the force which polarizes it is there a minimum. At the 

 maximum polarizing angle, Q is oi.ly 79° because the glass is inca- 

 pable of reflecting more light at that angle, otherwise more would 

 have been polarized. The value of Q then rises to its maximum at 

 78° T, and descends to its minimum at 90° ; but the polarizing 

 force has not increased from 56° 45^ to 78° 7' as the value of (p' 

 shows. It is only the quantity of reflected light that has increased, 

 which occasions a greater quantity of light to disappear from the 

 extraordinary image of the analysing rhomb. 



