1317 
reduce the matter to its original (“virginal’’) state before the beginning 
of every series of measurings, which was effected by heating it up to 
a little above the second point of transition. The current was kept 
constant during the measurements. 
Every series of measurements progressed as follows. 
A, The radiation of the Nernsr-burner is intercepted and con- 
sequently the galvanometer records the zero-condition. 
B. The radiation is admitted, the substance being in the virginal 
condition. 
- The magnetic field is excited. 
The magnetic field is removed. 
The radiation is intercepted. 
The radiation is admitted. 
The magnetic field is excited. 
The magnetic field is removed. 
The radiation is intercepted. 
mm oO 
Fig. 2. Perpendicular magnetic field of 1100 Gauss. 
_ The figures 2 and 3 show the phenomenon for a field of 1100 
Gauss. 
“A ‘ E \ 
Fig. 3. Horizontal magnetic field of 1100 Gauss. 
In order to understand their meaning it may be stated that to 
magnify the ordinates implies the diminishing of the extinction. 
The difference between the two phenomena is very characteristic. 
Whereas the perpendicular field excited for the first time a 
‘temporary increase of the extinction, nothing of the sort is observed 
84* 
