220 Me POWER'S THEORY OF 



If we substitute for L, M, N, the expressions at the commence- 

 ment of No. (13), we shall find 



^L-M-N = A{L) + B{M) + C{N), where 



^ = 2*i.(l-«2) + 2*2.(l-*,)-2*i.(l -*i)-2 52.(l-«2) 

 = 2 *, - 2 *,«2 + 2 *2 - 2 «i*8 - 2 *, + 2 «i' - 2 *2 + 2 «/ 

 = 2*,*- 4*1*2 + 2*/ 

 = 2(*i-*,f. 



= -(*!- s^f. 



= -{(i-*0-(i-*.)}' 

 = -(«i-*2)'; 



.-. ^L-M-N={s,-s,)\{2 (L) - {M) - {N)} 

 The effect of the disturbance in the direction GF, is therefore 



consequently if (i) be greater than ^ — '-^ — '- , or, if the capillary 



affinity of the opposite fluids exceed an arithmetic mean between 

 the capillary affinities of the two fluids for fluids of their own kind, 

 the tendency will be to depart still farther from the position of 



