338         Dr.  Gundry  on  the  Asymmetrical  Action  of  an 
no  importance  in  the  case  where  diffusion  plays  the  chief 
part;  and  therefore  we  may  suppose  that  the  mercury  ions 
which  come  into  solution  practically  all  disappear  instanta- 
neously in  the  form  of  the  undissociated  complex,  and  with 
the  same  rapidity,  the  mercury  ions  required  for  the  opposite 
phase  of  the  current  (from  electrolyte  to  electrode)  are 
supplied  from  the  complexes. 
Let  us  suppose  that  the  equilibrium  in  a  reaction 
(where  A'  represents  the  anion,  and  HgxAy  the  formula  of 
the  complex  salt)  is  reached  with  infinite  velocity,  and  cor- 
responds to  a  very  small  mercury  ion  concentration. 
Let  c  be  the  mercury  ion  concentration  in  the  neighbourhood 
of  the  small  electrode. 
Co  the  same  in  the  neighbourhood  of  the  large  electrode. 
.ft „-.  —  ~ — &. 
v,  v0  the  corresponding  concentrations  of  the  undissociated 
complexes. 
Then  v  =  acx,         v0  =  <rc0x 
by  the  law  of  mass  action,  where  <r  is  a  large  constant.  The 
concentration  of  the  anion  is  considered  constant  on  account 
of  the  presence  of  an  indifferent  electrolyte  with  the  same 
anion. 
The  equations  now  become 
&=<fc' ^ 
where  £  =  0,                  i^sm  »t            $v  / 
—      =S,I€K^Z *     (2) 
(3)' 
=  yz  ,  i'  =  i', 
The  equation  (2)'  is  arrived  at  by  supposing  that  each- ion 
which  comes  into  the  solution  disappears,  and  x  such  ions 
correspond  to  one  complex  molecule. 
As  before,  wre  have 
p  = loo-  -= log  -  =      log      1+        cos  I  mt  +  -  )  >  , 
r        n       °  c0       nx      °  v0      x  I  v0        \  4  /  J 
where  -r>,  &o  i     -*       R@ 
B= j=~,     and     \  — , 
qex^/tcm 
P 
-*{?-(-+i)-i£M~3+-}- 
