274 H. NAGAOKA AND K. HONDA 



1 



7^(0 



h" HR. {A) 



in field H, and that the mean longitudinal magnetization caused 

 by twisting a ferromagnetic wire carrying an electric current C 

 amounts to 



1 



?rW 



2 



h"C. (B) 



The reciprocal relation between these two phenomena is thus 

 apparent at a glance. We shall next show how the same pheno- 

 mena are reciprocally connected with the torsion produced by the 

 interaction of the longitudinal and circular magnetizations. 



The stress components in a magnetic medium as given by 

 Kirchhoff' are as follows : 



î;= -(^ + /.• + ^) ß'-+ 4(^ + /■• - ^y ) («^+ ir-+ f). 

 ^. = -(^ + I- + 4-) r+ |(-^ + /.• - z^-' ) (-+ /5^+f). 



-^,= i;= - y^^ + ic + ^ y«- 



Taking the axis of in the axial line of the wire, and two other 

 axes in the plane perpendicular to it, we see that the component 



