23 AKT. 3.— H. XAGAOKA AND K. HONDA. 



nickel is indeed reniarkuble, as the changes here noticed far exceed those 

 hitherto ob.served in simple ferromagnetic substances. The change in 

 2*d% Ni is nearly 4:0 times greater than in soft iron ; in ûict, the 

 motion of the capillary meniscus could be easily followed by the naked 

 eye, as the displacement, wliicli took place almost instantaneously 

 with the making of the current, was nearly 5 mm. in tlie strongest 

 field at our disposal. Even the 25% Xi sample showed a volume 

 change, which, in spite of the minute magnetizability, could be dis- 

 tinctly measured by a microscope. 



From the above result, it f(jll<)ws that there is a certain alloy, 

 whose percentage content of nickel will lie somewhere between 2b% 

 and 36%, wdiich will indicate the greatest change of volume ; the 

 changfe will indeed be the orreatest, that we can observe in the ferro- 

 maofnetic substances of common (occurrence. 



When we consider the magnitude of the volume change in 

 nickel steels and compare it with that observed in iron or nickel, 

 we are struck with the immensity of the effect, which is not shared 

 in such an extraordinary degree by either of the constituents of the 

 alloy. The same remark applies to the magnetizability of the 

 samples. That the alloy of two strongly magnetizable substances 

 should give rise to an almost neutral body is in no way an object of 

 curiosity, when considered in the same light as the enormous eftect 

 of magnetization on the bulk of the alloy. In the present instance, 

 we are at a loss to decide which of the two metals plays a predomi- 

 nating part in the magnetostriction of nickel steel ; perhaps a 

 complete study of the subject from the lowest percentage to the 

 pure nickel, and the comparative investigation of the phenomena in 

 the succeedinof stao^es will reveal to us the o-roupin^-s of the constituent 

 metals while entering into an alloy, as Avell as the part played by them 

 in the magnetization and in the various ])henomena attending it. 



