crystallized, bodies on homogeneous light. 
59 
in. 
TableIV. Rochelle salt, perpendicular to the optic axis. Thickness=z<J. J 94425 . 
Corresponding 
inclinations. 
Ordinary pencil. 
Extraordinary, 
Remarks, &c. 
o 
201 3C 
0 / 
330 1C 
White .... 
White 
Poles PP' for 
207 IC 
Exceeding pale blue 
Exceeding pale pink 
red rays. 
20 9 c 
Exceeding pale pink . 
Exceeding pale blue 
210 3c 
Very pale blue 
Very pale pink 
212 3c 
Very pale pink 
Very pale blue 
213 2C 
Very pale blue 
Very pale pink 
215 25 
Pale pink 
Pale blue green 
2l6 40 
Pale blue 
Pale yellow pink 
218 O 
Pink 
Blue green 
219 29 
Pale blue 
Pale yellow pink 
220 58 
Pink 
Greenish blue 
White 
Very pale purple 
222 30 
Blue 
Yellow pink 
22 3 45 
309 30 
Yellowish pink 
Greenish blue 
224 50 
308 15 
Pale greenish blue 
Yellowish pink 
Blue 
Pale pinkish yellow 
226 10 
307 0 
Pale pink 
Pale greenish blue 
306 10 
Pale yellow 
Dark blue 
White 
Pale purple 
227 25 
Bluish or greenish white 
Very pale violet pink 
228 30 
Blue 
Very pale yellow 
Violet almost imperceptible . 
White 
229 3 
3°4 10 
Pure white 
Pure white 
Virtual poles 
Exceeding pale yellow 
A little violet 
p, p'. 
229 50 
Pale yellow 
Very narrow dark blue 
Very pale tawny orange 
Blue, sombre and pale 
231 20 
302 20 
Fine purplish crimson 
Pale yellow green 
Very pale purple 
White 
232 25 
Very pale green 
Fine crimson 
White 
Pale purple 
234 0 
299 20 
Splendid crimson 
Very pale green 
Pale purple 
White 
235 4 ° 
Very pale green 
Rich crimson 
While 
Pale purple 
236 23 
296 15 
Rich crimson 
Very pale green 
Pale purple . 
White 
238 50 
2 94 35 
Pale blue green . 
Good pink, almost crimson 
White 
Very pale purple 
240 12 
2 9 2 55 
Pink rather pale 
Pale greenish blue 
White 
White 
242 10 
291 30 
Pale blue 
Pale yellowish pink 
243 40 
289 50 
Pale pink yellow 
Pale blue 
245 10 
287 45 
Very pale blue 
Very pale yellow 
246 50 
286 45 
Very pale yellow green 
Very pale lilac blue 
248 25 
284 55 
Pale lilac 
Yellow green 
White 
White 
250 40 
282 30 
Fine yellow green 
Fine lilac 
White , • 
White 
252 57 
280 12 
Lilac 
Fine yellow green 
White 
White 
256 5 
2 77 25 
Fine yellow green 
Fine lilac 
White 
White 
259 20 
274 40 
Pale lilac 
Fine yellow green 
261 40 
271 40 
White 
White 
266 40 
266 40 
Green yellow . 
Pale lilac . . 
The middle tint 
