$6 Mr. J. F. W. Herschel on the action of 
in. 
Table I. Sulphate of baryta. Thickness of plate = 0.11964. 
Corresponding 
inclinations. 
Ordinary pencil. 
Extraordinary. 
Remarks, &c. 
O / 
43 55 
0 / 
*34 37 
Pink 
Very pale blue green . 
Tints beyond 
45 0 
! 33 4 2 
Bluish green 
Pink 
the poles. 
46 0 
i 3 2 45 
Rich pink 
Beautiful green 
132 0 
Whitish . 
Dull purple 
46 58 
J 3 i 37 
Splendid green 
Rich crimson 
131 0 
Blue 
Yellow 
47 53 
* 3 ° 45 
Crimson 
Fine green 
Yellow inclining to orange 
Blue 
Yellow 
Purple 
48 51 
129 30 
Blue green 
Rich crimson 
Blue 
Orange 
128 58 
Purple 
Pale yellow 
Rich crimson red 
Pale green or greenish white 
Fine orange 
Light blue 
Pale orange yellow 
Dark blue 
1 
50 58 
127 45 
White 
Sombre & very narrow purple 
Bluish white 
Scarlet or fiery red 
Light blue 
Orange 
Sombre greenish blue 
Ruddy white, or very pale 
52 0 
126 50 
Dirt}’ and very sombre purple . 
White [orange 
Sombre and narrow pinkish red . 
White 
Very pale violet or pinkish white 
Greenish white 
White 
Dirty bluish green 
53 1 
125 47 
White 
Narrow and very sombre violet 
Virtual poles 
125 30 
White slightly yellowish 
Violet [purple 
pp', or points 
125 0 
Pale and dirty olive green 
Violet white 
of coincidence. 
Very narrow violet 
White 
OO' 
124 30 
Blue very sombre and narrow . 
White slightly yellowish 
Light blue 
Pale yellow 
Bluish or greenish white 
Indifferent purplish pink 
55 2 5 
123 30 
Yellowish white . 
Sombre and narrow purple 
Light yellow 
Dark blue 
Dull orange pink 
Pale greenish blue 
5 6 33 
122 15 
Sombre purple 
Pale yellow green 
Blue 
Yellow 
57 30 
Pale green 
Fine pink verging to crimson 
57 5 ° 
1 2 1 0 
Pale yellow 
Purple 
58 15 
120 15 
Light yellowish pink 
Greenish blue 
The polesP,P' 
Rich pink 
Bluish green 
Tints between 
59 12 
119 35 
Pale purple 
Greenish white 
the axes. 
Blue green 
Crimson 
60 45 
1 1 8 20 
White 
Very pale purple 
1 '7 40 
Pink 
Blue green 
62 0 
117 5 
Pale purple 
Whitish 
62 58 
iif> 25 
Greenish blue 
Pink 
63 2 5 
•IS ^5 
White 
Dull purple 
64 28 
1 14 47 
Pink 
Bluish green 
65 40 
1132 
Greenish blue 
Pink 
67 30 
iii 30 
Pin k 
Pale greenish blue 
69 15 
1 10 0 
Pale greenish blue 
Pale pink 
