2 ART. 12. --K. HON'DA, S. SHIMIZU, AXD S. KUSAKABE : 



Wiedemunii^^ did does not seem to be justifiable. Wartinium-'^ u.sed 

 Cliladui's figure to investigate the change of elasticity of magnetized 

 iron and steel plates, and also examined the sound accompanying 

 longitudinal and transversal viijrations of maofnetized iron wires. 

 Xo influence of magnetization was (observed. Trèves^^ put in vibration 

 two tuning forks having the same period of vibration. When one 

 of them was put in a coil and magnetized by a strong electric current, 

 its vibration was accelerated producing the beat; but when tlie current 

 was broken, the beats were no longer audiljle and the two notes 

 were in unison. This shows an increace of elasticity by ma- 

 gnetization. H. T<Hnlinson*' found that the elono-ation of an iron wire 

 by loading is independent of magnetization. Bock'^^ found the effect to 

 be less than j%, if there was any. By passing an electi-ic current 

 through a stretched pianoforte wire, M.G. Noyes*" noticed an increase 

 of elasticity, which was less than \%. But in his later experiment'^ 

 he did not accept the conclusion, to which he was led by his former 

 experiment. We can, however, have from his tables an increase of 

 •elasticity ; but he attributed it to the effect of temperature. Maurain®' 

 also found a small increase of frequency in a tuning fork placed in a 

 very strong magnetic field. In the investigation of the etfect of tension 

 upon the magnetic elongation of a pianoforte wire, B>. Brackett^' 

 observed that the effect of tension was to diminish the magnetic 

 elongation, and he ascribed it to an increase of elasticity. J. S. 



1) Wipdeiiiana's Electricität HI. 813. 



2) Wartmann, Ana. de Chim. et de Phys. 24, 363, 1848. 



3) Treves, Couip. Rend. 67, 321, 1868; Archives des soc nat. X. S. 33, 7-t, 1368. 



4) Toiiilinson, Proc. Roy Soc. 40, 447, 1886. 



5) Bock, Wied. Ann. 54, 442, 1895; Phil. Mag. (5) 39, 548, 1895. 



6) Noyes, Pby. Rev. (4) 2, 277, 1895. 



7) Noyes, Phy. Rev. (6) 3, 432, 1896. 



8) Maurain, Comp. Rend. 121» 248, 1895. 



9) Brackett, Phy. Rev. (5) 5, 257, 1897. 



