1908-9.] Dissymmetrical Separations in the Zeeman Effect. 83 
on the plates, the turning points in the intensity of the middle component 
are approximately as stated in the table. It will be seen that correspond- 
ing to this more rapid variation in intensities, there is a similar variation 
in the character of the dissymmetry found in the lines. Again, there are 
exceptions to the rule that the dissymmetry depends on the amount of the 
rotation of the plane of polarisation. 
These experiments show that in using a quartz lens and a concave 
grating to obtain the Zeeman Effect cases of dissymmetry arise which are 
due to the angle between the planes of vibration of the components and the 
lines of the grating, for this dissymmetry varies with the intensities, which, 
in their turn, vary with that angle. That all cases of dissymmetry cannot 
be so accounted for is shown by the exceptions to this rule where abnormal 
dissymmetry is found instead of the normal which might be expected, and 
vice versa. These point to the possibility of the presence of the couplings 
between electrons of different vibration frequencies assumed by Professor 
Voigt, in consequence of which the two triplets containing the coupled 
electrons become respectively an abnormal and a normal dissymmetrical 
triplet. The intensities of the outside components are in most cases the 
same, and this also is in accordance with the theory. In the photographs 
of these substances, tungsten and molybdenum, are also to be found many 
other examples of dissymmetry among lines which break up into many 
components. 
This research was carried out in the University of Gottingen, and I take 
this opportunity of expressing my gratitude to Professor Voigt, and the 
pleasure I had in having the apparatus there, which is so splendidly 
adapted for such research, set at my disposal. 
{ Issued separately December 30 , 1908 .) 
