1886.] On Specific Inductive Capacity. 455 



where 4t7re=Af(V), when the whole space is occupied by fluid, and 

 the distance is x. 



The charge being constant we have — 



= { J-/00 }rfA l+ {£ + (A- A0/'(V) } dV, 



and for the purpose of transforming the integral 



whence 



4,^« = {^+(A-A 1 )/(V)}<iV, 



y 



rf =i| {/CV)~}^. (4) 



dp 



Writing with Quincke K s for the dielectric constant determined by 



a measurement of P, we have by substituting in (4) /(V) = — — , and 



x 



integrating as though K 5 were constant, 



4i7T X Z 



K ^- 1 + -y2-' ( 6 ) 



which may be taken as the definition of K„ 



whence K f = ^ J (7) 



but from (5) we have, since in fact K = ^^2, 



But K 



-I 



) dx I Sttx^ 



