OF ARTS AND SCIENCES. 123 



experimental values. The discrepancy, we believe, can be explained 

 also by a consideration of the transformations of energy in the 

 dielectric. 



3. The periodicity which we have studied is most manifest when the 

 variable capacity of the air condenser bears a suitable relation to the 

 time of the electrical surgings. 



4. The electrical waves are apparently unaffected by passing 

 through glass which is placed in an intense magnetic field, the 

 direction of the electrical strain being perpendicular to that of the 

 magnetic strain. The displacement currents of Maxwell in this case 

 do not appear to affect the time of electrical surgings. This con- 

 clusion, however, may be modified by experiments which we shall try 

 on a more extended scale. 



