On Polarization of Light by Refraction. 227 
angles to that of reflexion. This difference is exactly’ what 
might have been expected from the opposite character of the result 
ing polarization, the poles of the particles of light which were form- 
erly repelled by the force of reflexion, beipg now attracted by the re- 
fracting force. 
In this experiment the action of the two surfaces is davidupatkie 
succession, so that we cannot deduce from the maximum rotation of 
21° 19’, the real action of the first, or-of a single surface, which must 
be obviously more than half of the action of the two surfaces, because 
the planes of polarization have been widened before they Polina the 
action of the second surface. 
In order to obtain the rotation ee pale ie 
due to a single surface, I took a 
prism of glass ABC (Fig. 2.) hav- 
ing such an angle BAC, that a ray 
RR, incident as obliquely as pos- 
sible, should emerge in a direction 
Rr perpendicular to the surface 
AC. I took care thatthis prism was well annealed, ded T caused 
the refraction to be performed as near as possible to the vertex A, 
where the glass was thi most free from the in- 
fluence of any polarizing structure. ‘Tn this way I obtained ™ ~ 
R 
acs GLASS. 
= kn les of Inclination of Planes ab, ed, (Vig. 1.) 3 
“oc to the Plane of Reflexion. Rotation. 
EE: her): a a er B4o 10... sc dticieds oe ee, 
af yt 54 50. * . . . * 47 ns Ba . . * . fe 9 ie . 
- 0 
eT next made the following experiments with two ods. of hs 
the one a piece of parallel plate glass, and the oi other a piece of very 
thin crowa._The latter had the advantage of separating the refi ete z 
from the transmitted light. a 
PLATE GLASS. : - CROWN GLASS. 
Incidence. Inclination. Rotation. Inclination. Rotation. 
| . 45° 0 oY. 6°. 0. 
at yt te ae ST 
See 8 ere ee ee 
ee. fet es , ORL, 
PF. ae eee eee ea D a 4 wees nee fs = i s 
Me. ole. . 1616. . CDs ee. 
