﻿Forces 
  produced 
  hy 
  Flowing 
  Solutions. 
  603 
  

  

  have 
  proved 
  most 
  successful 
  in 
  the 
  explanation 
  of 
  electro- 
  

   motive 
  forces, 
  i. 
  e. 
  with 
  the 
  osmotic 
  views 
  put 
  forward 
  by 
  

   Xernst*. 
  Perrin^s 
  view 
  leads 
  him 
  to 
  the 
  consequence 
  that 
  

   the 
  electromotive 
  force 
  does 
  not 
  depend 
  on 
  the 
  nature 
  of 
  the 
  

   wall. 
  The 
  osmotic 
  theory 
  makes 
  the 
  potential 
  difference 
  

   always 
  a 
  function 
  of 
  the 
  special 
  nature 
  of 
  the 
  properties 
  of 
  

   the 
  two 
  phases 
  between 
  which 
  it 
  takes 
  place. 
  Haber^s 
  theo- 
  

   retical 
  deductions, 
  from 
  which 
  we 
  started, 
  are 
  grounded 
  on 
  

   the 
  same 
  standpoint. 
  

  

  The 
  diffusion 
  theory 
  may 
  account 
  for 
  differences 
  in 
  the 
  

   phenomena 
  caused 
  by 
  the 
  use 
  of 
  different 
  solids^ 
  by 
  help 
  of 
  

   the 
  assumption 
  that 
  a 
  specific 
  absorbing 
  power 
  for 
  ions 
  exists 
  

   at 
  solid 
  surfaces, 
  but 
  the 
  explanation 
  becomes 
  in 
  this 
  way 
  

   still 
  more 
  indefinite, 
  and 
  does 
  not 
  show 
  a 
  clearer 
  connexion 
  

   with 
  the 
  osmotic 
  theory. 
  

  

  Though 
  the 
  diffusion 
  theory 
  has 
  up 
  till 
  the 
  present 
  time 
  

   been 
  unable 
  to 
  give 
  more 
  than 
  qualitative 
  results, 
  w^hilst 
  

   every 
  step 
  of 
  the 
  osmotic 
  theory 
  guides 
  to 
  quantitati\e 
  

   results, 
  certain 
  difficulties 
  arising 
  especially 
  in 
  the 
  electric 
  

   behaviour 
  of 
  colloidal 
  substances 
  w^hen 
  considered 
  from 
  the 
  

   osmotic 
  standpoint, 
  have 
  led 
  to 
  some 
  support 
  being 
  given 
  to 
  

   the 
  former 
  theoryf. 
  

  

  Finally, 
  the 
  fact 
  that 
  the 
  osmotic 
  theory, 
  according 
  to 
  our 
  

   experiments, 
  is 
  able 
  to 
  explain 
  qualitatively 
  a 
  result 
  which 
  till 
  

   now 
  seemed 
  only 
  explicable 
  by 
  the 
  diffusion 
  theory; 
  and, 
  on 
  

   the 
  other 
  hand, 
  the 
  differences 
  still 
  remaining 
  between 
  the 
  

   predictions 
  of 
  the 
  osmotic 
  theory 
  and 
  our 
  results, 
  suggest 
  

   further 
  experimental 
  work 
  in 
  this 
  direction 
  ; 
  this 
  will 
  be 
  

   carried 
  out 
  by 
  one 
  of 
  us 
  in 
  this 
  Institution. 
  

  

  This 
  problem 
  was 
  undertaken 
  by 
  us 
  at 
  the 
  suggestion 
  

   of 
  Professor 
  Haber 
  ; 
  and 
  we 
  desire 
  to 
  express 
  our 
  sincere 
  

   thanks 
  for 
  the 
  interest 
  which 
  he 
  has 
  showm 
  and 
  for 
  the 
  help 
  

   which 
  he 
  has 
  given 
  throughout, 
  both 
  with 
  the 
  experimental 
  

   difficulties 
  and 
  with 
  the 
  theory. 
  

  

  Phys. 
  Chem. 
  Institut 
  u. 
  Phys. 
  Institut, 
  

  

  Technische 
  Hocbscliule; 
  

  

  Karlsruhe. 
  

  

  * 
  See 
  Wied. 
  Jnn. 
  Iviii. 
  Beilage, 
  Heft 
  8, 
  1896. 
  

  

  t 
  It 
  may 
  be 
  remembered 
  that 
  Billiter 
  {Zeitschr. 
  f. 
  Eledrochemie, 
  xv. 
  

   p. 
  160,1009) 
  considers 
  that 
  the 
  diffusion 
  phenomena 
  have 
  only 
  a 
  secondary 
  

   infiuenre. 
  

  

  2S 
  2 
  

  

  