286 On Polarization of Light by Reflexion. 
This formula is equally applicable to a single pencil of polarized 
light of the same intensity as the pencil of partially polarized light. 
In all these cases it expresses the quantity of light really or appa- 
rently polarized in the plane of reflexion 
In order to show the quantity of ‘light polarized at different angles 
of incidence, I have computed the following table for common light, | 
and suited to glass in which m=1.525. 
PLATE GLASS. 
Inclination of 
Angle of| Angle of |Plane of Polari-|Quantity of Light|Quantity of Po-|Ratio of 3: 
{incidence Retraction} zation to Plane | reflected out of | larized Light | larized to 
i. v. of Reflexion. 1000. Rays. Q. Reflected 
9. Light. 
& <ph sissy es 1 
0°. 01.020 45 0 43.23 0 0 
10 0} 6 32 43 51 43.39 1.74 | 0.04000 
20 0/12 58) 40 13 43.41 7.22 | 0.16618 
25 0) 16 -5 37 21 43.64 11.6 0.26388 
30 0;19 84) 33 40 44.78 17.25 | 0.3833 
35 0;22 6]| 29 8 46.33 24.37 | 0.5260 
40 0| 24 56 23 41 49.10 33.25 |0.6773 
45 0/27 374) 17 224 53.66 44.09 | 0.82167 
50 0/30 9 10 18 61.36 57.36 | 0.9360 
56 45| 33 15 0 79.5. 79.5 1.000 
60 0| 34 36 43 93.31 1 0.9628 
65 0; 36 28 12 45 124.86 112.7 0.90258 
70 O 2 18. 32 162.67 129.80 | 0.79794 
75 0/39 18 26 52 257.26 152.34 | 0.59154 
78 0) 39 54 |. 30 44 329.95 157.67 | 0.47786 
79 0;40 4 31 59 359.27 157.69 | 0.43892 
80 0/40 13 33 13 391.7 156.6 0. 
82 44) 40 35 36 22 499.44 145.4 0.29112 
84 0 40 42 38 2 560.32 134.93 | 0.2408 
85 0 40 47 39 12 616.28 123.75 | 0.2008 
86 0/40 51 40 22.7 676.26 108.67 | 0.16068 
87 0/40 54 41 32 744.11 89.83 | 0.12072 
88 0/40 574) 42 42 819.9 65.9 8 
89 0/40 58 43 51 904.81 36.32 | 0.04014 
90 0140 58 45 0 1000.0 0.0000 
As the preceding formula is deduced from principles which have 
been either established by experiment or confirmed by it, it may be 
expected to harmonize with the results of observation. At allt 
its where the pencil is either wholly polarized or not polarized at 
all, it of course corresponds with experiment: but though in so boc 
