OF ELLIPTIC POLARIZATION. 
309 
polarization has a maximum at about 50°, declining rapidly to zero at 41°, and 
on the other side slowly to zero at 90° of incidence. 
When one reflexion from steel was combined with two total reflexions from 
glass at 54^°, the inclination of the plane of the restored ray was 30^°, an 
arithmetical mean between 45° that of total reflexion, and 17° that of steel, for 
45° + 17° 
= 31°. 
With silver the inclination was 42^°, 
and 
45° + 39° 48' 
= 42° 24'. 
If we make the metallic reflector receive the circularly polarized ray in 
every azimuth, we shall find that in azimuth 90° the circular polarization is 
compensated by a metallic reflexion above 80°. As the azimuth diminishes 
to 0°, this angle of compensation diminishes also, passes through 73° in the case 
of steel, and diminishes to a number depending on the angle of incidence at 
which the total reflexion is made. We are thus enabled to study the pheno- 
mena of circular polarization by the aid of metals, and to obtain results at 
which it would be exceedingly difficult, if not impossible, to arrive by any 
other method. This subject, however, presents too wide a field to be treated 
thus incidentally. 
Sect. III. — On the complementary colours produced hy successive reflexions 
from the polished surfaces of metals. 
I have already given a general account of the phenomena of colour pro- 
duced by successive reflexions ; and I have shown that the tints thus produced 
are by no means the same as those of crystallized plates, as they do not rise in 
the scale by successive reflexions. 
In my early experiments on total and metallic reflexions, I regarded the two 
classes of phenomena as exactly the same, mutatis mutandis ; and in commu- 
nicating these results to Dr. Young, I pointed out their coincidence with his 
theoretical views. Dr. Young noticed these experiments in the following 
manner*. 
“ Dr. Brewster has also shown that the total reflexion of light within a 
denser medium, and the brilliant reflexion at the surfaces of some of the 
metals, are capable of exhibiting some of the appearances of colour as if the 
* Art. Chromatics, Supp. Encyc. Brit. p. 157. 
