﻿770 
  Dr. 
  J. 
  Kunz 
  on 
  the 
  Corpuscular 
  

  

  Let 
  us 
  suppose 
  that 
  there 
  is 
  a 
  thin 
  layer 
  between 
  the 
  

   substances 
  A, 
  B 
  in 
  which 
  the 
  transition 
  from 
  A 
  to 
  B 
  takes 
  

   place 
  gradually, 
  and 
  let 
  us 
  reckon 
  the 
  abscissa 
  x 
  from 
  one 
  of 
  

   the 
  boundaries 
  of 
  this 
  layer. 
  

  

  i 
  

  

  4« 
  rr 
  BlogN 
  j 
  

   Xdx 
  = 
  - 
  - 
  1 
  — 
  ^ 
  — 
  dx 
  

   5 
  e 
  ox 
  

  

  X&=V„-V 
  s 
  =^Tlog|. 
  

  

  V 
  a 
  and 
  Vj 
  denote 
  the 
  potentials 
  in 
  the 
  metals 
  A 
  and 
  B, 
  

   N, 
  the 
  number 
  of 
  free 
  corpuscles 
  in 
  the 
  metal 
  A, 
  N 
  2 
  that 
  in 
  

   metal 
  B. 
  

  

  The 
  potential-differences 
  which 
  arise 
  in 
  this 
  way 
  are 
  not 
  

   comparable 
  with 
  the 
  Volta 
  differences 
  of 
  potential 
  between 
  

   metals 
  in 
  contact. 
  The 
  experimental 
  results, 
  however, 
  cannot 
  

   be 
  in 
  accord 
  with 
  this 
  theoretical 
  calculation 
  for 
  well 
  known 
  

   reasons. 
  Let 
  us 
  remark, 
  in 
  addition, 
  that 
  we 
  have 
  assumed 
  

   a 
  perfect 
  metallic 
  contact 
  ; 
  if 
  this 
  condition 
  is 
  not 
  satisfied 
  

   quite 
  different 
  phenomena 
  take 
  place, 
  when 
  an 
  electric 
  force 
  

   is 
  acting 
  between 
  two 
  metals 
  or 
  even 
  between 
  two 
  pieces 
  of 
  

   the 
  same 
  metal. 
  

  

  These 
  new 
  phenomena 
  occur 
  in 
  the 
  coherer, 
  which 
  we 
  

   shall 
  consider 
  later 
  on 
  in 
  the 
  light 
  of 
  the 
  second 
  theory 
  of 
  

   metallic 
  conduction 
  due 
  to 
  J. 
  J. 
  Thomson. 
  

  

  § 
  2. 
  Tliermoelectric 
  Force 
  in 
  an 
  unequally 
  heated 
  Metallic 
  Bar, 
  

  

  Let 
  AB 
  be 
  a 
  bar 
  of 
  metal, 
  and 
  let 
  the 
  temperature 
  increase 
  

   from 
  A 
  to 
  B. 
  If 
  we 
  assume 
  the 
  number 
  of 
  corpuscles 
  to 
  be 
  

   independent 
  of 
  the 
  temperature, 
  there 
  is 
  a 
  diffusion 
  of 
  cor- 
  

   puscles 
  with 
  a 
  large 
  amount 
  of 
  kinetic 
  energy 
  from 
  the 
  

   hotter 
  parts 
  of 
  the 
  metal 
  to 
  the 
  colder 
  ones. 
  In 
  consequence 
  

   of 
  the 
  collisions 
  which 
  the 
  corpuscles 
  make 
  with 
  the 
  atoms 
  

   of 
  the 
  metal, 
  resulting 
  in 
  alterations 
  in 
  the 
  energy, 
  the 
  cor- 
  

   puscles 
  will 
  carry 
  heat 
  from 
  the 
  hot 
  to 
  the 
  cold 
  parts 
  of 
  the 
  

   metal. 
  This 
  transference 
  of 
  heat 
  takes 
  place 
  without 
  a 
  

   change 
  in 
  the 
  number 
  of 
  corpuscles 
  in 
  unit 
  volume, 
  without 
  

   a 
  transference 
  of 
  the 
  electric 
  charges, 
  and 
  therefore 
  without 
  

   the 
  production 
  of 
  an 
  electromotive 
  force. 
  This 
  process 
  is 
  a 
  

   completely 
  irreversible 
  one, 
  like 
  the 
  diffusion 
  of 
  two 
  volumes 
  

   of 
  a 
  gas 
  of 
  different 
  temperatures 
  but 
  of 
  the 
  same 
  number 
  

   of 
  molecules 
  per 
  unit 
  volume. 
  No 
  mechanical 
  work 
  can 
  be 
  

   produced 
  by 
  such 
  a 
  process. 
  If 
  the 
  number 
  of 
  corpuscles 
  

   per 
  unit 
  volume 
  in 
  a 
  metal 
  does 
  not 
  depend 
  on 
  the 
  tempera- 
  

   ture, 
  there 
  can 
  be 
  no 
  electromotive 
  force 
  along 
  the 
  bar 
  to 
  

  

  