( 842 ) 



Here III formed an asymmetric doublet, of which the component 

 on the red side was the narrower; V a faint doublet; for VI the 

 middle became somewhat lighter. 



With a vertical plane of polarisation all the bands became vaguer, 

 most of them slightly shifting towards the red ; in the field the bands 

 widened or further faded away ; now only III gave a symmetrical 

 doublet. 



Band in the blue-green at — 193": with a horizontal plane of 

 polarisation ;i=r: 511,9, /?„= 0,13 |uf.t; in a field of 42 kgs. a doublet 

 appeared: width of the lefthand line 0,13, of the righthand line 

 0,18, of the light interval 0,09 mi ; the whole made the impression 

 of perhaps being a quadruplet. With a vertical plane of polarisation 

 the phenomenon was analogous but less clear. 



Group of bands in the green at — 193°: 6 bands were measured. 



42 Kilogauss. — Plane of polarisation horizontal — Thickness 0,3 mm. 



Band II gave an ordinary doublet; that of III remained rather 

 dark in the middle, so that we may infer a more complex structure 

 in this case also. 



With a vertical plane of polarisation all this was less clearly 

 visible, band II still gave a clear doublet, for III only a trace of 

 this could be perceived. 



Group of bands in the yellow at — 193°. Two rather sharply 

 defined bands 576,0 (/i„ = 0,3) and 586,0 (/?„ = 0,14) exhibited a 

 distinct widening of 0,05 p^u in a field of 42 kgs. The intermediate 

 bands are too wide for this kind of observation. 



Group of bands in the orange-red at — 193° : 5 bands were 

 measured. 



