512 



M. F. Osmond's Considerations 



of the polarized particles, will be exactly equal to the whole 



,' ;■ ..100,, 

 of the iron a, i. e. to mp, ex. varying from to j^g, the 



temporary magnetism will be represented by the diagonal A. 



Y -rv A. 





/ f 





/ / 



p 



/ / 

 / t 





/ / 





/ / 





/ / 





/ / 









{» / cx 

















7? ^v. 







JP "''" 





^ c ^" 





m X 



As to the permanent magnetism, in regarding it as the 

 relative number of particles of a which remain polarized after 

 the cessation of the magnetizing force, it will be a fraction of 



mp, all the greater as -r is smaller for the steel under consi- 

 deration. In other words, the polarized particles ex. will be 

 more immovable the closer the network /3. 



Under the supposition that the quantity mr of the particles 

 a which remain polarized after the interruption of the 

 magnetizing force (that is to say, the permanent magnetism 



as defined) is proportional to the percentage of iron /3, ~L 

 we can write 



mpx 



K np 



100' 



K being a numerical coefficient equal to or less than unity. 

 Since 



mp = mO = .1', 



np = 100 — mp = 100 — mO, 



= 100-0, 



^lOO-a 



100 



K 



V 100} • 



Accordingly the permanent magnetism is represented by a 

 portion of a parabola whose axis is parallel to that of Y. It 



