406 Mr. R. T. Glazebrook on the Molecular 



Thus, substituting for f &c, 



tfF 2/*C da! _ fzX _ An Bfi 



P 



du f , a d0 f t cW . , • • 



since a, /3, y are constant. Put — =^- for ^r- , the total elec- 

 ' ax 2 



tromotive force impressed on the element parallel to the axis 



of x, and, as before, let 



fiB 1 



7-lT 

 K being the specific inductive capacity ; then, if P be the 

 electromotive force parallel to x ? 



Then 



+ P=-g- • • • (20) 



Thus P, the electromotive force parallel to x, is, on the mole- 

 cular vortex theory, composed of four parts in a field of strong 



magnetic force. The first is — =-, the rate of change of the 



vector potential. The next is 



r 



and this is exactly similar in form to the electromotive force 

 discovered by Mr. E. H. Hall and already alluded to. The 

 third may be written _ 



where f) is the impressed magnetic force, f)' the resultant of 

 the force arising from the displacement of the medium, and 

 e the angle between them. In Mr. Hall's experiments this 

 angle would be 90°, and therefore the term would vanish. 



