THE PARTIAL POLARIZATION OF LIGHT BY REFLEXION. 
75 
Diamond. 
Angle of 
Incidence. 
Angle of 
Refraction. 
Inclination of Plane of Polarization 
to Plane of Reflexion. 
Observed. Calculated. 
Difference. 
CO 
O 
o 
0' 
. 24° 12' . 
O' 
o 
o 
O' 
o 
o 
0 ° o' 
85 
0 
. 24 6 . 
. . 34 30 
. . 33 56 . 
. +0 34 
80 
0 
. 23 48 . 
. . 24 0 
. . 23 12 . 
. +0 48 
75 
0 
. 23 19 . 
. . 14 30 
. . 13 8 . 
. +1 22 
70 
0 
. 22 39 . 
. . 4 30 
. . 3 54 . 
. +0 36 
67 
43 
. 22 17 . 
..00 
. . 0 0. 
0 0 
60 
0 
. 20 47 . 
. . 12 30 
. . 11 41 . 
. +0 49 
50 
0 
. 18 18 . 
. . 24 0 
. . 23 30 . 
. +0 30 
These differences, which at an average amount to 46|', are also within the 
limits of the errors of observation. 
In all these experiments the value of x was 45° ; but in order to determine 
the law of variation for <p, when x varies from 0° to 90°, I took a crystal of 
quartz with a fine natural surface parallel to its axis ; and I found that at an 
angle of incidence of 75°, and when x was 45°, the inclination of the plane of 
polarization to the plane of reflexion was 26° 20'. I then varied x, and obtained 
the following results : 
lues of x. 
Inclination of Plane of Polarization. 
<p Observed, <p Calculated. 
Difference. 
0° . 
... 0° 0' . 
0° 0' . . 
0° 0' 
10 . 
... 4 54 . 
4 29 . . 
. . +0 25 
20 . 
... 10 0 . 
. . 10 16 . . 
. . — 0 16 
30 . 
... 15 50 . 
. . 16 2 . . 
. . — 0 12 
35 . 
'. . . 20 0 . 
. . 19 12 . . 
. . +0 48 
40 . 
... 23 30 . 
. . 22 40 . . 
. . +0 50 
45 . 
... 26 20 . 
. . 26 27 • • 
..-07 
50 . 
... 30 0 . 
. . 30 40 . . 
. . -0 40 
55 . 
... 35 30 . 
. . 35 23 . . 
..+07 
60 . 
... 40 0 . 
. . 40 45 . . 
. . —0 45 
70 . 
... 53 0 . 
. . 53 49 . . 
. . —0 49 
80 . 
... 70 0 . 
. . 70 29 . . 
. . -0 29 
90 . 
... 90 0 . 
. . 90 0 . . 
0 0 
l 2 
