﻿aiid 
  Chemical 
  Reactions 
  in 
  Heterogeneouii 
  Systems. 
  549 
  

  

  into 
  the 
  solution, 
  and 
  vice 
  versa, 
  is 
  evidently 
  the 
  greater, 
  the 
  

   larger 
  the 
  surface 
  from 
  which 
  they 
  pass 
  into 
  the 
  solution, 
  

   or 
  the 
  larger 
  the 
  surface 
  of 
  contact 
  of 
  the 
  solid 
  and 
  liquid, 
  

   because 
  the 
  reaction 
  goes 
  on 
  all 
  along 
  at 
  every 
  point 
  of 
  the 
  

   solid 
  in 
  contact 
  with 
  the 
  solution. 
  Hence 
  my 
  equation 
  

  

  ar 
  ^ 
  ^ 
  

  

  These 
  extremely 
  simple 
  and 
  clear 
  conceptions 
  about 
  the 
  

   cause 
  of 
  the 
  shape 
  of 
  mx 
  aeneral 
  equation, 
  I^oyes 
  and 
  Whitney, 
  

   Bruner 
  and 
  Tolloczko, 
  Nernst 
  and 
  Brunner 
  tried 
  to 
  replace, 
  

   singling 
  out 
  a 
  special 
  case 
  of 
  solution 
  of 
  solids 
  from 
  all 
  the 
  

   rest 
  of 
  the 
  reactions, 
  by 
  other 
  conceptions. 
  Let 
  us 
  now 
  see 
  

   what 
  these 
  conceptions 
  are, 
  how 
  they 
  simplify 
  matters 
  purely 
  

   theoretically, 
  and 
  how 
  far 
  they 
  are 
  confirmed 
  by 
  true 
  

   experiments. 
  Noyes 
  and 
  Whitney, 
  dealing 
  with 
  solubility 
  

   of 
  salts, 
  write 
  : 
  — 
  •' 
  We 
  can 
  imagine 
  that 
  the 
  solid 
  substance 
  

   is 
  always 
  surrounded 
  with 
  an 
  infinitely 
  thin 
  layer 
  of 
  a 
  

   saturated 
  solution, 
  and 
  that 
  the 
  process 
  consists 
  in 
  a 
  diffusion 
  

   from 
  this 
  layer 
  to 
  the 
  rest 
  of 
  the 
  solution, 
  which 
  is 
  kept 
  by 
  

   stirring 
  homogeneous. 
  Then 
  according 
  to 
  the 
  known 
  laws 
  

   of 
  diffusion 
  the 
  speed 
  of 
  reaction 
  will 
  be 
  directly 
  proportional 
  

   to 
  the 
  differences 
  of 
  concentration 
  of 
  the 
  saturated 
  solution 
  

  

  and 
  that 
  of 
  the 
  solution, 
  i. 
  e., 
  -7' 
  = 
  A'(C' 
  — 
  C)." 
  This 
  view 
  

  

  was 
  adopted 
  first 
  by 
  L. 
  Bruner 
  and 
  Tolloczko, 
  who 
  went 
  

   a 
  step 
  further, 
  and 
  assumed 
  that 
  the 
  velocity 
  constant 
  is 
  

   nothing 
  else 
  but 
  the 
  diffusion 
  constant^ 
  and 
  later 
  on 
  thev 
  

   introduce 
  also 
  the 
  idea 
  of 
  a 
  finite 
  layer 
  3 
  &c. 
  The 
  views 
  of 
  

   these 
  investigators 
  were 
  later 
  on 
  fully 
  adopted 
  and 
  followed 
  

   by 
  Nernst 
  and 
  Brunner, 
  who 
  instead 
  of 
  D 
  use 
  Bruner 
  and 
  

  

  Tolloczko's 
  ^, 
  and 
  make 
  a 
  step 
  further 
  stilly 
  by 
  trying 
  to 
  

  

  explain 
  the 
  equations 
  of 
  Boguski, 
  Spring, 
  Haber, 
  and 
  

   Lorenz, 
  giving 
  speed 
  of 
  chemical 
  reactions 
  in 
  heterogeneous 
  

   systems, 
  as 
  diffusion 
  equations 
  also. 
  With 
  the 
  last 
  we 
  

   shall 
  deal 
  in 
  detail 
  later 
  on. 
  In 
  this 
  first 
  publication 
  I 
  

   shall 
  restrict 
  myself 
  principally 
  to 
  molecular 
  reactions 
  only. 
  

  

  Returning 
  to 
  the 
  work 
  of 
  Bruner 
  and 
  Tolloczko, 
  as 
  ^ 
  

  

  

   had 
  to 
  be 
  made 
  equal 
  to 
  the 
  velocity 
  constant, 
  they 
  soon 
  got 
  

   the 
  result 
  that 
  if 
  the 
  diffusion 
  constants 
  were 
  not 
  to 
  upset 
  the 
  

   theory, 
  3 
  or 
  the 
  layer 
  of 
  Noyes 
  and 
  Whitney 
  cannot 
  be 
  

   taken 
  to 
  be 
  " 
  infinitely 
  thin/' 
  but 
  must 
  have 
  a 
  measurable 
  

   thickness. 
  In 
  this, 
  as 
  well 
  as 
  in 
  my 
  identical 
  equation, 
  

  

  