﻿548 
  Dr. 
  Meyer 
  Wilderman 
  on 
  Velocity 
  of 
  Molecular 
  

  

  this 
  is 
  a 
  very 
  strange 
  thing 
  to 
  do, 
  when 
  we 
  are 
  asked 
  to 
  

   tnke 
  their 
  results 
  as 
  quantitative 
  measurements 
  and 
  to 
  give 
  

   them 
  all 
  the 
  credence 
  we 
  have 
  to 
  give 
  the 
  quantitative 
  results, 
  

   instead 
  of 
  leaving 
  it 
  to 
  the 
  reader 
  to 
  see 
  for 
  himself 
  what 
  

   value 
  those 
  A's 
  really 
  possess. 
  Especially 
  is 
  this 
  regrettable 
  

   when 
  we 
  are 
  invited 
  to 
  accept 
  a 
  theory 
  on 
  the 
  basis 
  of 
  con- 
  

   clusions 
  which 
  are 
  mostly 
  based 
  upon 
  differences 
  in 
  the 
  values 
  

   of 
  A, 
  which, 
  it 
  is 
  quite 
  evident, 
  are 
  often 
  smaller 
  than 
  the 
  

   experimental 
  error 
  of 
  the 
  method 
  itself. 
  

  

  § 
  3. 
  The 
  Theory 
  of 
  Molecular 
  Reaction^ 
  including 
  the 
  Solution 
  

   of 
  Solids 
  in 
  a 
  Solvent, 
  Also 
  on 
  the 
  Diffusion 
  Theory, 
  

  

  In 
  the 
  first 
  place 
  let 
  me 
  state 
  again, 
  in 
  somewhat 
  greater 
  

   detail, 
  the 
  content 
  of 
  my 
  equation 
  as 
  far 
  as 
  it 
  concerns 
  the 
  

   solution 
  of 
  salts, 
  before 
  I 
  pass 
  to 
  the 
  consideration 
  of 
  its 
  content 
  

   according 
  to 
  the 
  diffusion 
  theory. 
  I 
  assume 
  that 
  every 
  sub- 
  

   stance 
  has 
  a 
  solution 
  pressure, 
  which 
  causes 
  the 
  solid 
  to 
  pass 
  

   into 
  the 
  solvent, 
  whenever 
  brought 
  into 
  contact 
  with 
  the 
  same; 
  

   that 
  this 
  goes 
  on 
  until 
  the 
  solution 
  becomes 
  saturated, 
  so 
  that 
  

   the 
  solution 
  pressure 
  of 
  the 
  solid 
  is 
  kept 
  in 
  equilibrium 
  by 
  the 
  

   counter 
  osmotic 
  pressure 
  of 
  the 
  saturated 
  solution, 
  which 
  

   (leaving 
  out 
  of 
  consideration 
  galvanic 
  cells 
  where 
  we 
  have 
  to 
  

   deal 
  with 
  electrostatic 
  forces) 
  at 
  equilibrium 
  are 
  equal 
  ; 
  that 
  in 
  

   case 
  of 
  an 
  unsaturated 
  solution, 
  before 
  equilibrium 
  is 
  reached, 
  

   the 
  solution 
  pressure 
  of 
  the 
  solid 
  is 
  greater 
  than 
  the 
  counter 
  

   osmotic 
  pressure 
  of 
  the 
  solution, 
  and 
  the 
  substance 
  of 
  the 
  solid 
  

   is 
  still 
  driven 
  into 
  the 
  solution 
  by 
  a 
  force, 
  which 
  is 
  directly 
  

   proportional 
  to 
  the 
  difference 
  of 
  the 
  existing 
  solution 
  pressure 
  

   and 
  the 
  counter 
  osmotic 
  pressure, 
  or 
  to 
  the 
  difference 
  of 
  the 
  

   osmotic 
  pressure 
  of 
  the 
  solution 
  al 
  equilibrium 
  (which 
  is 
  equal 
  

   to 
  the 
  solution 
  pressure 
  of 
  the 
  solid) 
  and 
  the 
  osmotic 
  pressure 
  

   of 
  the 
  solution 
  at 
  the 
  time 
  r, 
  or 
  also 
  directly 
  proportional 
  to 
  the 
  

   difference 
  of 
  the 
  concentration 
  of 
  the 
  solution 
  at 
  equilibrium 
  

   and 
  its 
  concentration 
  at 
  the 
  time 
  r, 
  since 
  the 
  osmotic 
  pressure 
  

   is 
  directly 
  proportional 
  to 
  the 
  concentration. 
  Similarly, 
  in 
  

   case 
  of 
  an 
  over-saturated 
  solution, 
  the 
  solution 
  pressure 
  of 
  

   the 
  solid 
  is 
  smaller 
  than 
  the 
  counter 
  osmotic 
  pressure 
  of 
  the 
  

   solution, 
  and 
  the 
  substance 
  in 
  solution 
  is 
  driven 
  into 
  the 
  

   solid 
  by 
  a 
  ibrce, 
  which 
  is 
  directly 
  proportional 
  to 
  the 
  differ- 
  

   ence 
  of 
  the 
  existing 
  osmotic 
  pressure 
  of 
  the 
  solution 
  and 
  the 
  

   solution 
  pressure 
  of 
  the 
  solid 
  (or 
  osmotic 
  pressure 
  of 
  the 
  

   solution 
  at 
  equilibrium). 
  The 
  speed 
  with 
  which 
  the 
  solid 
  

   passes 
  into 
  the 
  solution 
  or 
  from 
  the 
  solution 
  into 
  the 
  solid, 
  

   I 
  therefore 
  take 
  to 
  be 
  directly 
  proportional 
  to 
  the 
  driving- 
  

   force, 
  and 
  the 
  number 
  of 
  molecules 
  passing 
  from 
  the 
  solid 
  

  

  