180 WEBER ON THE CONNEXION OF DIAMAGNETISM 



increase with the deflection AND, and may be represented by 



D sin (p, 

 where D is a constant quantity which may be named the tnole- 

 cular force of direction. If, now, besides this molecular force of 

 direction, the magnetizing force X act upon the molecular 

 current in the direction NX, which encloses the angle XND 

 = u with the line of the directive force, the molecular current 

 will by this be drawn or deflected through the angle AND = ^, 

 and for the determination of the new position of equilibrium 

 we have the following equation, 



X sin u cos ^ = (D +X cos u) sin <f), 



X sinz< 



or tan A = tT~r v — ~~ — • 



^ D + A cos u 



From the deflection ^ the increase of the magnetic moment of 

 the molecular current, decomposed in the direction of the force 

 X, may be determined. If the total unchangeable magnetic 

 moment of the molecular current be denoted by ft, then before 

 the deflection that decomposed in the direction of the force X 

 was 



= jEx,cosw; 

 after the deflection, 



= wcos (m— <^) ; 



hence the required increase <r, 



a?=|u, (^cos (2^— ^)--cosw). 

 Substituting here for 4) the value of it as given by the above 



X sin u . 



equation, tan <^ = y^ . v » we obtam 



^ ' ^ D + Xcosw' 



{X + DCOSM 1 



^(XX 4- DD + 2XD^^ "" ^^^ ^J • 

 For a system of molecular currents whose magnetic axes, in 

 their original positions of equilibrium, point in all directions 

 without distinction, the number of molecular currents whose 

 axes form an angle u with the direction NX of the force X are 

 to be set proportional to sin u. Let it be required to determine 

 the magnetic moment y which results from the rotation of all 

 molecular currents of the system, by the force X. 

 To this end let the value of x above found be multiplied by 



