﻿322 
  E. 
  M. 
  Wellisch 
  — 
  Distribution 
  of 
  the 
  Active 
  Deposit 
  

  

  By 
  plotting 
  the 
  curves 
  in 
  this 
  manner 
  the 
  two 
  sets 
  become 
  

   comparable 
  ; 
  the 
  continuous 
  curves 
  afford 
  a 
  measure 
  of 
  the 
  

   fraction 
  of 
  the 
  total 
  number 
  of 
  positive 
  ions 
  which 
  reach 
  the 
  

   cathode 
  corresponding 
  to 
  any 
  potential 
  V, 
  while 
  the 
  broken 
  

   curves 
  similarly 
  afford 
  a 
  measure 
  of 
  the 
  fraction 
  of 
  the 
  total 
  

   number 
  of 
  positively 
  charged 
  particles 
  which 
  settle 
  on 
  the 
  

   cathode. 
  

  

  A 
  very 
  large 
  number 
  of 
  experimental 
  results 
  were 
  used 
  in 
  

   order 
  to 
  plot 
  the 
  curves 
  ; 
  for 
  the 
  sake 
  of 
  simplification 
  the 
  

   individual 
  results 
  are 
  not 
  recorded 
  in 
  the 
  diagram. 
  

  

  The 
  curves 
  in 
  fig. 
  2 
  all 
  refer 
  to 
  the 
  values 
  obtained 
  when 
  

   the 
  air 
  with 
  which 
  the 
  emanation 
  was 
  mixed 
  was 
  thoroughly 
  

   dried 
  as 
  described 
  in 
  Section 
  4. 
  The 
  effect 
  of 
  a 
  small 
  amount 
  

   of 
  water 
  vapor 
  was 
  especially 
  marked 
  when 
  the 
  applied 
  

   potential 
  was 
  small. 
  In 
  illustration 
  of 
  this 
  point 
  some 
  of 
  the 
  

   results 
  obtained 
  for 
  dried 
  and 
  undried 
  air 
  are 
  recorded 
  below 
  : 
  

  

  Air 
  at 
  1 
  atmosphere 
  : 
  

   V 
  = 
  8 
  volts 
  

  

  dried 
  with 
  special 
  caution 
  

  

  containing 
  slight 
  traces 
  

   of 
  water 
  vapor 
  

  

  It 
  is 
  worthy 
  of 
  notice 
  that 
  the 
  presence 
  of 
  small 
  quantities 
  of 
  

   water 
  vapor 
  does 
  not 
  appreciably 
  diminish 
  the 
  fraction 
  of 
  posi- 
  

   tive 
  ions 
  which 
  reach 
  the 
  cathode, 
  whereas 
  the 
  effect 
  on 
  the 
  num- 
  

   ber 
  of 
  positively 
  charged 
  deposit 
  particles 
  is 
  considerable. 
  It 
  

   has 
  for 
  some 
  time 
  been 
  known 
  that 
  water 
  vapor 
  is 
  effective 
  in 
  

   causing 
  increased 
  recombination 
  of 
  ions, 
  but 
  the 
  above 
  results 
  

   serve 
  to 
  show 
  that 
  the 
  ions 
  are 
  not 
  nearly 
  so 
  sensitive 
  to 
  the 
  

   presence 
  of 
  vapor 
  as 
  the 
  active 
  deposit 
  particles. 
  

  

  Referring 
  again 
  to 
  the 
  curves 
  of 
  fig. 
  2, 
  it 
  is 
  seen 
  that 
  in 
  gen- 
  

   eral 
  the 
  'activity' 
  curve 
  for 
  any 
  given 
  voltage 
  lies 
  below 
  the 
  

   ionization 
  curve 
  for 
  the 
  corresponding 
  voltage. 
  This 
  is 
  almost 
  

   certainly 
  to 
  be 
  ascribed 
  to 
  the 
  increased 
  recombination 
  with 
  

   negative 
  ions 
  which 
  Occurs 
  with 
  the 
  active 
  particles 
  as 
  com- 
  

   pared 
  with 
  the 
  positive 
  ions 
  even 
  when 
  the 
  air 
  with 
  which 
  the 
  

   emanation 
  is 
  mixed 
  is 
  thoroughly 
  dried. 
  

  

  Cathode 
  Deposit 
  for 
  very 
  small 
  quantities 
  of 
  emanation 
  

   in 
  dry 
  Air. 
  

  

  6. 
  If 
  the 
  curves 
  in 
  fig. 
  2 
  are 
  produced 
  so 
  as 
  to 
  intersect 
  the 
  

   axis 
  of 
  ordinates, 
  we 
  obtain 
  points 
  which 
  afford 
  a 
  measure 
  of 
  

   the 
  fraction 
  of 
  ions 
  and 
  of 
  positively 
  charged 
  deposit 
  particles 
  

   which 
  would 
  be 
  obtained 
  by 
  the 
  application 
  of 
  the 
  corresponding 
  

  

  A 
  v 
  

  

  I,/I 
  1M 
  

  

  160 
  

  

  38-4 
  

  

  •61 
  

  

  3-21 
  

  

  31-2 
  

  

  •61 
  

  

  3-21 
  

  

  