﻿396 
  Mr. 
  H. 
  P. 
  Walmsley 
  on 
  the 
  Distribution 
  of 
  the 
  

  

  curves 
  is 
  a 
  measure 
  o£ 
  the 
  positively 
  charged 
  deposit 
  existing 
  

   In 
  the 
  chamber 
  at 
  any 
  time. 
  If 
  this 
  were 
  corrected 
  for 
  the 
  

   diffusion 
  of 
  the 
  active 
  matter 
  to 
  the 
  walls 
  of 
  the 
  vessel, 
  the 
  

   resulting 
  values 
  would 
  show 
  the 
  law 
  of 
  loss 
  of 
  charge 
  of 
  

  

  Fig. 
  9. 
  

  

  ■5 
  ^•0 
  2-5 
  

  

  Time 
  in 
  ,yinut£$. 
  — 
  - 
  

  

  the 
  active 
  deposit. 
  It 
  seems 
  extremely 
  probable 
  that 
  the 
  

   curve 
  would 
  satisfy 
  the 
  ordinary 
  law 
  of 
  recombination 
  of 
  

   positive 
  ions, 
  but 
  the 
  experimental 
  values 
  are 
  not 
  sufficiently 
  

   accurate 
  to 
  test 
  the 
  point. 
  The 
  evidence 
  shows, 
  however, 
  

   that 
  actinium 
  B 
  continues 
  to 
  recombine 
  until 
  it 
  is 
  all 
  elec- 
  

   trically 
  neutral. 
  

  

  The 
  necessity 
  of 
  employing 
  the 
  cotton- 
  wool 
  plug 
  Gr 
  to 
  

   remove 
  active 
  deposit 
  from 
  the 
  emanation 
  as 
  it 
  enters 
  the 
  

   chamber, 
  can 
  be 
  well 
  shown 
  with 
  the 
  apparatus. 
  The 
  curves 
  

   fig. 
  10 
  show 
  the 
  resulting 
  measurements 
  obtained 
  by 
  this 
  

   method, 
  when 
  the 
  plug 
  G 
  is 
  omitted. 
  

  

  VI. 
  

  

  Attention 
  has 
  been 
  drawm 
  throughout 
  this 
  paper 
  to 
  the 
  

   necessity 
  of 
  eliminating 
  dust 
  from 
  the 
  air 
  into 
  which 
  the 
  

   emanation 
  is 
  introduced. 
  The 
  role 
  played 
  by 
  dust 
  was 
  

   forcibly 
  brought 
  out 
  during 
  the 
  work 
  on 
  actinium 
  B, 
  for 
  it 
  

   was 
  found 
  that 
  if 
  this 
  was 
  not 
  removed, 
  it 
  was 
  possible, 
  

   under 
  certain 
  circumstances, 
  to 
  obtain 
  more 
  activity 
  on 
  the 
  

   -anode 
  than 
  on 
  the 
  cathode. 
  Atmospheric 
  air 
  is 
  known 
  to 
  

  

  