64 



AET. 4. — K. HOXDA AXD T. TERADA. 



^, SO that relation (o) can not be satisfied even ai^proximately. 

 In concluding the descriptions of the results of our experi- 

 ments, the following remarks may be added. Since we measured 

 the changes of elasticity and of rigidity for the same wires of 

 ferromagnetic metals and alloys, it will be now interesting to cal- 

 culate the change of Poisson ratio by magnetization. Since the 

 change of elastic constants is considerably affected by tension, it 

 is necessary to calculate the change of the ratio from the 

 changes of elasticity and rigidity for the same tension. 



If <y be the Poisson ratio, we have 



E 

 K /dE dK\ 



a 



K 



TP 



The value of -y^ used in the calculation of the following table 



K 



ÙE 



oVv 



is that for no field ; and the values of -^ and -^ are those ob- 

 tained by the tension effect of the magnetic elongation and by 

 the Barus's method respectively, for in these two sets of experi- 

 ments, the stress was first applied and then the magnetizing field. 



TABLE XL. 



