+9, 
126 
2. To one color A or wave 
length belongs an “afinite number 
of directions of vibration, but in as 
many different planes of polariza- 
tion. 
3. To an infinite number - 
lanes of polarization belongs a 
infinite number of directions of 
ibration. The ere are per- 
pendicular to each plan 
4. The direction of eeinicn of 
the extraordinary ray is perpendic- 
ular to its plane. There is but one 
such direction ; it is parallel to the 
. A color B, that is a wave 
length, i is in all azimuths united to 
one direction of vibration. 
- To one plane of polarization 
belongs one direction of vibration. 
Sctentific Intelligence. 
To one color A or wave length — 
belongs atly one direction of vie 
bration. 
f 
n infinite number of planes 
of polactine belongs but one di- 
rection of vibration. 
The direction of vibration of 
the extraordinary ray lies in the 
plane of polarization. There is an 
infinite number of such directions. 
They lie in - aint pergende: 
ular to ye 
Aco or Bi is Pada to an infinite 
santas oad directions of vibrations 
one in each azimut 
To one ne of polarization 
belongs an infinite number of di- 
rections of vibration. 
(2.) Obdservation.—In the vertical zones whose edges are oclpendies 
lar tu the axis of the crystal, in all azimuths. The ordinary ray '$ 
polarized in the direction of the axis with the color A. The extraordi- 
nary ray is polarized perpendicular to the axis, and goes from the di- 
rection of the observation, beginning perpendicular to the axis, to the 
direction of the axis itself, passing from the color B to the color A. 
Observed in the direction of the axis the colors of both rays perpendicu- 
= to each other are perfectly similar in all azimuths and poss — the 
eA 
. 
Consequences and Hypotheses as above. 
7. The direction of vibration of The direction of vibration of the 
the ordinary ray is perpendi ordinary ray lies in its lane. 
to its There is but one such here isan infinite number of such 
direction for e every plane. It is directions fur every plane. 
perpendicular fo the axis. include with the axis all p 
angles from 0° to 90°, 
. Toone olka: habe ene 
belong but one di ireciion of ra- 
t 
tion principal section only one such 
uch direc- It is Pog. eapitg to the 
, =n 0° parallel to the : 
perpendicular to the 
T o one color or wave er we : 
