﻿558 
  Dr. 
  Meyer 
  Wilderman 
  on 
  Velocity/ 
  of 
  Molecular 
  

  

  2 
  Jius 
  I 
  find 
  that 
  the 
  law 
  regulating 
  the 
  variation 
  of 
  the 
  velo- 
  

   city-constant 
  with 
  temperature 
  is 
  for 
  molecular 
  reactions 
  similar 
  

   to 
  the 
  law 
  of 
  van't 
  Hojf 
  for 
  homogeneous 
  reactions; 
  it 
  has 
  the 
  

   same 
  thermodynamic 
  explanation^ 
  i. 
  e. 
  is 
  in 
  connexion 
  with 
  the 
  

   maximum 
  work 
  performed 
  during 
  the 
  reaction 
  in 
  a 
  reversible 
  

   cycle. 
  I 
  will 
  show 
  in 
  my 
  publication 
  on 
  chemical 
  reaction 
  in 
  

   heterogeneous 
  systems 
  that 
  the 
  same 
  equation 
  holds 
  good 
  in 
  case 
  

   o£ 
  reaction 
  of 
  acids 
  &c. 
  upon 
  little 
  soluble 
  solids 
  and 
  confirm 
  

   it 
  also 
  upon 
  data 
  taken 
  from 
  the 
  investigations 
  of 
  other 
  reliable 
  

   scientists. 
  

  

  The 
  above 
  is 
  a 
  very 
  strong 
  and 
  reliable 
  proof 
  against 
  the 
  

   diffusion 
  conceptions 
  of 
  Noyes 
  and 
  Whitney, 
  Bruner 
  and 
  

   ToUoczko, 
  Nernst 
  and 
  Brunner. 
  As 
  to 
  the 
  percentage 
  

   increase 
  of 
  A, 
  this 
  gradually 
  drops 
  from 
  5'1 
  per 
  cent, 
  per 
  

   degree 
  between 
  1°*5 
  C. 
  and 
  17°-5 
  C. 
  to 
  3*64 
  per 
  cent, 
  between 
  

   40° 
  C. 
  and 
  60° 
  C, 
  instead 
  of 
  being 
  2*5 
  per 
  cent., 
  as 
  required 
  

   by 
  the 
  diffusion 
  theory 
  ; 
  and 
  this 
  increase 
  of 
  A 
  drops 
  with 
  

   rise 
  of 
  temperature 
  instead 
  of 
  rising. 
  

  

  (e) 
  My 
  further 
  question 
  is, 
  what 
  do 
  we 
  gain 
  by 
  the 
  Bruner- 
  

   Tolloczko's, 
  Nernst 
  and 
  Brunner's 
  hypothesis 
  ? 
  Nothing 
  

   either 
  in 
  clearness 
  or 
  in 
  generality 
  of 
  conception. 
  In 
  the 
  first 
  

   instance, 
  what 
  has 
  become 
  of 
  the 
  speed 
  with 
  which 
  the 
  solid 
  

   passes 
  into 
  the 
  thin 
  film 
  of 
  the 
  solution, 
  the 
  heterogeneous 
  

   reaction 
  proper 
  ? 
  and 
  which 
  law 
  regulates 
  this 
  reaction 
  ? 
  

   What 
  do 
  we 
  know 
  of 
  the 
  " 
  infinite 
  forces 
  at 
  play," 
  mentioned 
  

   by 
  Nernst 
  ? 
  Are 
  we 
  to 
  be 
  satisfied 
  by 
  mere 
  assertions 
  

   without 
  proof, 
  or 
  are 
  we 
  going 
  to 
  know 
  anything 
  about 
  this 
  

   speed 
  and 
  about 
  the 
  forces 
  at 
  play 
  and 
  the 
  mode 
  of 
  their 
  

   action 
  ? 
  In 
  the 
  theory 
  of 
  galvanic 
  cells 
  we 
  are, 
  at 
  any 
  rate, 
  

   consistent, 
  we 
  calculate 
  and 
  measure 
  the 
  solution-pressures, 
  

   whether 
  they 
  be 
  only 
  an 
  integration-constant 
  or 
  not. 
  We 
  

   get 
  solution-pressures 
  of 
  10^^ 
  or 
  10"^^ 
  atmospheres, 
  to 
  which 
  

   many 
  a 
  serious 
  scientist 
  objected, 
  but 
  we, 
  from 
  our 
  point 
  of 
  

   view, 
  adhere 
  to 
  them. 
  These 
  forces 
  are 
  great 
  enough 
  and 
  

   small 
  enough 
  to 
  show 
  us 
  that 
  if 
  Nernst 
  and 
  Brunner^s 
  theory 
  

   of 
  the 
  process 
  of 
  the 
  ordinary 
  solution 
  of 
  solids 
  at 
  their 
  

   surface 
  be 
  true, 
  this 
  theory, 
  as 
  given 
  to 
  us 
  at 
  present, 
  still 
  

   teaches 
  us 
  nothing 
  about 
  the 
  heterogeneous 
  reactions 
  proper 
  even 
  

   in 
  the 
  sphere 
  of 
  pure 
  abstraction. 
  I, 
  for 
  one, 
  would 
  object 
  to 
  

   this 
  method 
  of 
  treating 
  the 
  subject 
  of 
  molecular 
  reactions 
  as 
  

   a 
  clear 
  and 
  lucid 
  conception 
  of 
  a 
  phenomenon 
  which 
  we 
  wish 
  

   to 
  know, 
  even 
  if 
  pure 
  abstractions 
  were 
  all 
  that 
  interested 
  us. 
  

   Our 
  conceptions, 
  instead 
  of 
  becoming 
  simpler^ 
  became 
  compli- 
  

   cated, 
  and 
  we 
  are 
  thrown 
  face 
  to 
  face 
  with 
  neio 
  'unknown 
  

   problems 
  which 
  are 
  very 
  difficult 
  and 
  inaccessible 
  to 
  test, 
  while 
  

   the 
  content 
  and 
  the 
  conceptions 
  contained 
  in 
  the 
  equation, 
  

  

  