26 



ART. 8.-H. NAGAOKA AND K. HONDA: 



of volume. The (.'oiirse of the curve turns and jn-cK-eeds in the same 

 direction iis far as the present experiment goes. This character is 

 possessed by cast cobalt only among the numerous specimens of ferro- 

 magnetic substances hitherto experimented upon. Further we may 

 notice that the amount of the change is, to a certain extent, greater 

 in cobalt than in iron, steel, or nickel. 



The results of measurements in cobalt are given l^ehjw : — 



Nickel steel. (Fig. <S.) The volume change in nickel steel is cha- 

 racterized by the simplicity and the large amplitude of the ettect. 



The following table gives the measurements made <3n three speci- 

 mens of nickel steels containing different percentages of nickel. 



