S On the Power of Glass of Antimony to reflect Light. 



b = 1*25, and c — 9. We thus obtain the intensities in I lie 

 second column of the next Table; and comparing them with 



A 



those determined by experiment, we find as close an agree- 

 ment through a long range of incidences as could be expected 

 by those who have any idea of photometrical experiments. 



We find here again also the palpable inadequacy of the 

 formula: deduced from the undulatory theory of light, ac- 

 cording to which glass of antimony should have reflected, at 

 a perpendicular incidence, a quantity of light more than half 

 as much again as what it really does, namely, 13*33 rays of 

 every 100 rays incident. The polarizing angle for this speci- 

 men of glass of antimony appears to be about 65°, so that we 



