54 ARÎ. 7. — K. HONDA AND T. TERADA. 



By a similar consideration as Heyclweiller, A. Kolâcêk ob- 

 tained eqnation (8), and also a relation between magnetism and 

 twist, i. e., 



which coincides with equation (y). 



M. Cantone obtained two relations by equating the change 

 of magnetic energy due to a tension or a twist to the change of 

 elastic energy caused by magnetization, i. e. , 



=J^- (mi and r^= H~ (mi , 

 ' (iT Jo "" oL Jo ' 



where e,„ and r„, are the magnetic strains. By differentiating 

 the above equations with respect to H, we have 



9/ 





977 



Cantone tested the second relation by experiment and found a 

 satisfactory agreement in iron and nickel. For the first relation, 

 he also made a comparison between theory and exj^erimeiit, but 

 the data he used were taken from experiments by diflerent ])hy- 

 sicists, so that they do not refer to the same specimen. Thougl» 

 the comparison shows a satisfactory agreement, it is not certain, 

 whether it was l)v chance or not. 



