849 



they are in direct fields. However, il would be preposterous to con- 

 clude that the susceplibilitv is actually decreased bj the amount 

 found. Fnrtliei' work will be necessary for that. The choice of the 

 place of the suspended tube was rather unfortunate. It was situated 

 rather close to one of the slits in the linfoil. Even though capacity 

 effects appear to be absent this is dangerous because the magnetic 

 field in the neighborhood of the slit is not homogeneous. It is pos- 

 sible that the divergence between the \alues for alternating and direct 

 fields is due to insufficient caution in the manipulation of the sus- 

 pended tube and a slight displacement of il during the experiment. 

 This would hardlj' explain, however, the similarity ') of the results 

 for the two substances investigated. 



The writers wish to express their sincere thanks to Dr. H. R. 

 WoLTJKK for help in comparing the results with those in steady 

 fields and for makiiig unpublished results of his measurements 

 available. 



1) Especially, if the value 0.75 is too high and 0.51 too low (see notes §§ 4 and 5, 

 this similarity is perhaps not onlv qualitative, but also more or less quantitative. 



