358 M. C. Cheneveau on the Magnetic Balance 



i. e. in the direction Ox (fig. 1). If £f is the intensity of 

 specific magnetization, the value of the force is * 



f=mSr 



3 



(1) 



35 

 3* 



representing the space variation o£ the field. 







Fig. 1. 



As we are only concerned with feebly magnetic bodies, 

 the demagnetizing force arising from the magnetization of 

 the body is negligible, and we may assume that the intensity 

 of magnetization is proportional to the field. If we denote 

 the constant ratio between the intensity and field, or coefficient 

 of specific magnetization, by K, we have 



#=KH 



L i" 



consequently combining equations (1) and (2) 



3H„ 



/=K»E 



~dx 



(2) 



(3) 



Let us first suppose that the magnet producing the magnetic 

 field is at a considerable distance from the body. Then 

 H y = 0, and by (3) the force is zero. 



The body being always situated at 0, let the magnet be 

 brought up to the position I (fig. 2). If the force /is one 

 of attraction the body is of course paramagnetic, if of 

 repulsion, diamagnetic f . 



* We have /= 



dW 



W = MH , and M=^« 



Hence f=mP^. 



t If the sense Ox is taken as positive and we employ the true formula 

 the negative sign for the force indicates 



for the force, f— 





attraction and the positive sign repulsion. 



