126 Mr. W. R. Grove on the Transmission of 



when 



tt ' 



o/j denoting the expression jj \/b ,% —y li . 



In order to compare A x and A'* with each other, we can trans- 

 form the variables within the integral signs. If we take 

 jc^asinp, and y = bcosp, we obtain 



A * =fi jo dp ' siuyu " ^ r ^ ~^ r ^y 



M x =^dp . sin p . (^(R,) -0(R 2 )). 



Supposing that the point (a', /3') is in the periphery of the 

 first ellipse, and that its coordinates are denned by the analogies 

 a:ot' = a' :a and /3 : — b 1 : b, whereby (a, 0) and (a', /3') become 

 so-called corresponding points, we get 



V-^aW^ + ^-l), 



when we substitute in the expressions for R, and r, the values 

 ofa?,,^^ andy'p observing at the same time that a' 2 — a*=zV*—b % 9 

 because the ellipses are confocal. But as the coordinates of the 



point (a', ft') must satisfy the equation -2 + 72=1, we have 



a' 2 jS 2 



-5 + ^2 — 1=0, and consequently Rj^r,, In like manner it 



can be shown that R 2 =r 2 . The expressions within the integral 

 signs in the values of the components of attraction are, conse- 

 quently, equal, and we may thence conclude that 



A x :A' x =b:b'. 



Iu the same way we obtain 



A v :M y =a\a!. 



Gothenburgh, June 12, 1860. 



XIII. On the Transmission of Electrolysis across Glass. 

 By W. R. Gkove, Q.C., FM.S*. 



IF glass or an equally non-conducting substance be interposed 

 between electrodes in an electrolyte, so that there be no liquid 

 communication around the edges of the glass, it is hardly neces- 



* Communicated by the Author, having been read at the Chemical Section 

 of the British Association, June 28, 1860. 



