1908-9.] Dissymmetrical Separations in the Zeeman Effect. 81 
mainly from a part nearer the edge of the lens. Due to the difference in 
rotation thus produced, a difference in the relative intensities of the com- 
ponents was observed, and at the same time a difference in the dissymmetry. 
The measurements show that these changes are in no way due to a differ- 
ence of field strength acting on the light which falls on these two parts of 
the plate. Such a difference between the middle and the edge often occurs. 
These results tend to confirm the connection between the rotation and the 
dissymmetry produced by the apparatus used. The exceptions show that 
this does not explain everything. 
The problem was now to discover what component or components moved 
to produce the dissymmetry. Photographs of the same lines in tungsten 
were made in such a way that on the upper half of the plate came the 
spectral lines without separation, and under these were the separated com- 
ponents produced under the influence of the magnetic field. By means of a 
sheet, first the one half and then the other was covered. The same was also 
done with the lines in the iron spectrum. All the observations show that 
the centre component may sometimes remain stationary, and at other times 
be moved towards the red, or again towards the violet. The same is also 
true of the mean of the outer components. 
In the following table the results for tungsten are given : — 
Table III. — Tungsten. 
Field strength = 22, 000 gauss. 
Wave- 
length. 
S 
>» 
C/2 
C/2 
• rH 
Distance from Spectral 
line ( - towards Violet, 
+ towards Red). 
Q 
(mm.) 
o 
(Angstrom.) 
2488-89 
n 
( -0-117 
I +0-004 
[ +0-118 
- 0-114 
+ 0-003 
+ 0-115 
2522-14 
n 
f -0-116 
] +0-003 
( +0-117 
-0-112 
+ 0-003 
+ 0-114 
2555-23 
n 
f -0-122 
] +0-006 
{ +0-127 
-0-119 
+ 0-006 
+ 0-123 
2697-81 
a 
f -0-141 
] -0-005 
( +0-155 
-0-137 
-0-005 
+ 0-151 
Intensity. 
Wave- 
length. 
n 
2774-12 
5 / 
4 1 
2 r 
2774-60 
4 J 
5 ) 
3 r 
2856-20 
5 / 
6 ) 
4 f 
3049*80 
6 J 
c/2 
C/2 
a 
a 
a 
Distance from Spectral 
line ( - towards Violet, 
+ towards Red). 
(mm. ) 
O 
(Angstrom.) 
f - 0*138 
4 -0-005 
[ +0-143 
-0-135 
-0-005 
+ 0-140 
f -0-126 
4 -0-006 
t +0-130 
-0-124 
-0'006 
+ 0-128 
f -0-131 
-o-oio 
( +0-133 
-0-129 
-o-oio 
+ 0-130 
f -0-246 
4 -o-oii 
t +0-255 
-0*242 
-0-011 
+ 0-251 
-4-3 
In this experiment the lens was moved a little distance from its former 
position (Table I.), which gave a difference in rotation and an accompanying 
VOL. xxix. 6 
