1263 



being heated. The influence of the wall, feared by Brnedicks, is thus 

 completely eliminated; the surface of contact can be made very 

 small and in this surface the mercury is continuously renewed, thus 

 making the temperature gradient very large and stationary. 



The accompanying figure shows the arrangement used. To a 

 glass bulb .1 is attached a tube B^ the end of which has t^een 



82* 



