Transient Electric Currents produced by 



twisting Magnetized Iron, Steel, 



and Nickel Wires 



by 

 Hantarö Nagaoka. 



With Plates XXIX, XXX. 



The existence of a transient electric current when a magnetized 

 iron wire is suddenly twisted was first noticed by Matteucei.* The 

 same subject was afterwards investigated by Professor Ewing,f who 

 examined especially the hysteresis in circular magnetization, when 

 the direction of t lie magnetizing force was suddenly reversed. He 

 considers the transient current thus developed as an induction 

 current due to aeolotropic magnetic susceptibility produced in the 

 iron wire by twisting. He also found that the transient current in 

 the twisted wire, produced by reversing the magnetizing current 

 reaches a maximum at a certain strength of the masmetizin«" force ; 

 and that when the field is made greater the current is gradually 

 weakened, hut it never changes its direction. I was led to in- 

 vestigate the subject witli the aim of tracing some connection between 

 this transient current in nickel and the reversal of polarity in nickel 

 wire in a steady held, J when it is under the combined action of 

 torsional and longitudinal stresses. Preliminary experiments were 

 made during the Summer of 1888. My experiments were conducted 



* Annales de Chimie et de Physique, 185S ; or Wiedemann's Eleittrieität, Bel. III. 

 t Proe. R. S. Vol. 36, 1884.. 



X See my previous paper oa the combined effect of torsion and longitudinal stress on 

 the magnetization of nickel wire; this Journal Vol. II, or 1'hil. Mag. Feb. 1839. 



