Investigation of Polarized Light. 



II. 



Cell II., about J filled with KNa alloy. 



Angle of incidence = 65°. 



31 December, 1894. 



223 



Azimuth a 



0. 



15. 



30. 



45. 



60. 



75. 



90. 





Current-intensity (observed) . 

 Current-intensity (calculated) 

 Difference 



105-4 

 105-5 

 -0-1 



98-6 



98-6 

 00 



796 



79-7 



-0-1 



53-8 

 53-8 



o-o 



28-0 



28-0 



00 



8-7 



9-0 



-0-3 



2-1 

 2-1 





III. 



Cell III., with plate-glass windows. 



Angle of incidence = 65°. 



24 February, 1895. 



Azimuth a 



0. 



15. 



30. 



45. 



60. 



75. 



90. 



1-3 

 1-3 





Current-intensity (observed) . 

 Current-intensity (calculated) 

 Difference . , 



63-7 

 64-7 

 -10 



60-1 

 60-5 

 -0-4 



48-5 

 48-9 

 -0-4 



33-7 



330 



+0-7 



17-3 



17-2 



+0-1 



6-0 



5-5 



+0-5 





The numbers given as calculated current-intensities are 

 calculated from the formula 



J = A cos 2 a + B sin 2 a 

 in the following manner. The equation may be written 



J=(A— B) cos 2 a + B 



or 



J-B 



A-B=' 



cos a 



If we subtract the minimum value of B (corresponding to 

 a = 90°) from all the other values of J, and divide by the square 

 of the cosine of the corresponding azimuths, we ought to 

 obtain numbers nearly equal. Of these we take the arithmetic 

 mean (M), and write down the numbers obtained from the 

 formula 



J=Mcos 2 a + B 



for all azimuths as the calculated current-intensities. 



As we see from the foregoing tables, the result found with 



