﻿390 
  Mr. 
  H. 
  P. 
  Walmsley 
  on 
  the 
  Distribution 
  of 
  the 
  

  

  whole 
  deposit 
  reaches 
  the 
  wire 
  as 
  actinium 
  B, 
  the 
  recom- 
  

   bination 
  still 
  continues. 
  It 
  seems 
  extremely 
  probable, 
  

   therefore, 
  that 
  this 
  product 
  also 
  is 
  positively 
  charged 
  at 
  the 
  

   moment 
  of 
  its 
  creation. 
  

  

  IV. 
  

  

  If 
  the 
  anode 
  activity 
  be 
  a 
  measure 
  of 
  the 
  uncharged 
  active 
  

   deposit, 
  one 
  would 
  expect 
  that 
  an 
  external 
  source 
  of 
  ionization 
  

   would 
  increase 
  it. 
  To 
  test 
  this 
  point, 
  an 
  a-ray 
  tube 
  con- 
  

   taining 
  about 
  twenty 
  millicuries 
  of 
  radium 
  emanation 
  was 
  

   introduced 
  into 
  the 
  brass 
  tube 
  AB 
  (fig. 
  2) 
  and 
  exposures 
  

   made 
  in 
  the 
  usual 
  way. 
  In 
  order 
  to 
  be 
  able 
  to 
  study 
  the 
  

   distribution 
  of 
  the 
  active 
  deposit, 
  the 
  wire 
  was 
  charged 
  

   positively 
  to 
  16 
  volts. 
  This 
  was 
  repeated 
  two 
  days 
  later, 
  and 
  

   again 
  after 
  another 
  three 
  days. 
  The 
  a-ray 
  tube 
  was 
  then 
  

   removed 
  and 
  the 
  distribution 
  on 
  the 
  anode 
  again 
  found. 
  The 
  

   results 
  are 
  shown 
  graphically 
  in 
  fig. 
  6. 
  As 
  the 
  radium 
  

  

  Fij?. 
  6. 
  

  

  40 
  

  

  30 
  ^0 
  10 
  10 
  10 
  30 
  

  

  D/ST/INCE 
  EEIOM 
  CENTRE 
  OE 
  W/SfE 
  Y/V 
  MILLIMETffES 
  . 
  

  

  40 
  

  

  emanation 
  decays 
  and 
  therefore 
  the 
  ionization 
  diminishes, 
  

   the 
  active 
  deposit 
  collected 
  on 
  the 
  anode 
  decreases, 
  thus 
  

   showing 
  that 
  the 
  anode 
  activity 
  is 
  due 
  to 
  the 
  deposit 
  which 
  

   has 
  lost 
  its 
  charge 
  by 
  recombination. 
  The 
  displacement 
  of 
  

   the 
  maxima 
  is 
  probably 
  due 
  to 
  the 
  fact 
  that 
  the 
  a-ray 
  tube 
  

   was 
  not 
  placed 
  exactly 
  in 
  the 
  middle 
  of 
  the 
  tube 
  AB. 
  

  

  These 
  results 
  are 
  consistent 
  with 
  those 
  found 
  by 
  Wellisch 
  

  

  