JOURNAL OF THE COLLEGE OF SCIENCE, IMPERIAL UNIVERSITY, 

 TOKYO, JAPAN. 



VOL. XXI,, ARTICLE 4. 



On the Change of Elastic Constants of 



Ferromagnetic Substances by 



Magnetization. 



Bv 



CORRIGENDA. 



l*;i,UX' 1, for plate I-X read plate l-XU. 



The elastic constants of a substance in a magnetic field is 

 here defined as the ratio of the stress applied to the strain 

 caused thereby, the magnetic force constantly acting on the sub- 

 stance. The change of elasticity is then the difference of this 

 ratio, Nvhen the magnetic field is on, and when it is off*. In 

 the case of ferromagnetic substances, for which the hysteresis is 

 considerable, the change of elasticity so defined may, or may not 

 coincide with that of the same ratio, when the stress is first 

 applied and then the field. However, little attention seems to 

 have hitherto been paid to this point. Thus, in many*^ of the 

 experiments hitherto made regarding the change of elastic con- 



*) Guillemin, C. R. 22, 264 and 432, 1846. .T. S. Stevens and 11. G. Dorsc'y, Phy. R<'V. 

 (2) 9, 116, 1899. G. Wiedemann, Electricitat III, 796. C. Barns, Amer. Jour., 34, 175, 

 1887; Phy. Rev. XIII, 257, 1901. Day, Electrician, 39, 480, 1897. J. S. Stevens, Phy. 

 Rev. (3) 10, 111, 1900. K. Honda and S. Shimizu, Jour. Sc. Coll., Art. 12 and 13, Vol. 

 XVI, 1902. 



