MR. J. G. LEATHEM ON THE THEORY OF THE 
112 
the units being electromagnetic and C.G.S. And hence 
log’10 (- Co) = 11-8623, 
- Co = 7-283 X 10-“. 
25. Y 01 ' polar reflection, we derive from (44) and (36) 
2 c\ cos i{ — C(j) 7 (/ . 
= mod. 4 . cosi) cos i) ’ 
= - fj-i, = /X (say). 
Comparing this with the amplitude in equatorial reflection, we And ■ ^ 
jji (equatorial) _ , (— «„) sin i 
/X (polar) - mjo ' 
If — a^— 1400, yo = 850, i =51° 22 ', the value of this ratio, as calculated from 
theory, is -321. 
But the values ascribed to yo, and i correspond to the experiments of Sissingh 
and Zeeman ; and the latter found experimentally 
/X (Sissingh) ^ 
fx (Zeeman) 
So that here again we have a very fair agreement of the tlieoiy with experiment. 
Nickel. 
26. In the paper already quoted Zeeman gives a few measurements made by 
himself on polar reflection from nickel. He also quotes experimental results of 
Kundt (‘Wied. Ann.,’ vol. 23), and Drude (‘Wied. Ann.,’ vol. 46), which he 
expresses in a form similar to his own. These I have used to form the following 
tables, wherein the theoretical values of the phase and amplitude are in all cases 
calculated for yellow light. 
