﻿392 
  Mr. 
  H. 
  P. 
  Walmsley 
  on 
  the 
  Distribution 
  of 
  the 
  

  

  this 
  case 
  the 
  ionization 
  must 
  have 
  been 
  very 
  great, 
  and 
  hence 
  

   the 
  facility 
  for 
  recombination 
  was 
  correspondingly 
  increased. 
  

   An 
  increase 
  of 
  voltage 
  would 
  not 
  diminish 
  the 
  facility, 
  so 
  

   that 
  a 
  flat 
  curve 
  for 
  the 
  cathode 
  activity 
  would 
  be 
  obtained, 
  

   no 
  changes 
  occurring 
  in 
  the 
  anode 
  activity. 
  

  

  V. 
  

  

  It 
  was 
  thought 
  that 
  an 
  examination 
  of 
  the 
  recombination 
  

   of 
  the 
  positively 
  charged 
  active 
  deposit 
  atoms 
  over 
  much 
  

   longer 
  intervals 
  of 
  time 
  might 
  be 
  of 
  interest. 
  Although 
  no 
  

   essentially 
  new 
  facts 
  were 
  obtained, 
  yet 
  a 
  possible 
  cause 
  of 
  

   the 
  anomalous 
  behaviour 
  attributed 
  to 
  actinium 
  was 
  found. 
  

   The 
  method 
  consisted 
  essentially 
  of 
  injecting 
  emanation 
  into 
  

   a 
  chamber, 
  in 
  which 
  it 
  rapidly 
  transformed, 
  and 
  observing 
  

   the 
  ratio 
  of 
  the 
  activities 
  collected 
  by 
  positively 
  and 
  

   negatively 
  charged 
  rods, 
  after 
  various 
  intervals 
  of 
  time. 
  A 
  

   closed 
  metal 
  cylinder 
  (fig. 
  7) 
  was 
  fixed 
  rigidly 
  within 
  

   two 
  closely 
  fitting 
  bell-jars 
  A 
  and 
  B. 
  Two 
  glass 
  tubes 
  E 
  and 
  

   G 
  passed 
  through 
  the 
  stopper 
  of 
  the 
  lower 
  jar, 
  the 
  latter 
  

   being 
  connected 
  to 
  the 
  preparation 
  of 
  actinium 
  and 
  to 
  the 
  

   pump 
  which 
  forced 
  in 
  the 
  emanation. 
  The 
  upper 
  stopper 
  

   contained 
  a 
  short 
  brass 
  rod 
  into 
  which 
  a 
  copper 
  wire, 
  of 
  

   length 
  somewhat 
  greater 
  than 
  the 
  height 
  of 
  the 
  cylinder, 
  was 
  

   fixed. 
  To 
  prevent 
  the 
  active 
  deposit 
  being 
  collected 
  on 
  the 
  

   wire 
  before 
  an 
  exposure 
  was 
  made, 
  a 
  glass 
  tube 
  F, 
  which 
  

   could 
  be 
  raised 
  or 
  lowered 
  at 
  will, 
  passed 
  through 
  the 
  short 
  

   glass 
  tube 
  E 
  and 
  was 
  used 
  as 
  a 
  screen. 
  The 
  lower 
  end 
  of 
  E 
  

   dipped 
  into 
  a 
  vessel 
  containing 
  mercury, 
  so 
  making 
  the 
  whole 
  

   arrangement 
  air-tight. 
  The 
  actinium 
  preparation 
  was 
  con- 
  

   tained 
  in 
  a 
  wide 
  glass 
  tube 
  H. 
  A 
  tightly 
  packed 
  plug 
  of 
  

   glass 
  wool 
  at 
  each 
  end 
  of 
  the 
  tube 
  prevented 
  loss 
  of 
  the 
  

   material 
  when 
  a 
  charge 
  of 
  emanation 
  was 
  blown 
  into 
  the 
  

   apparatus. 
  The 
  electric 
  field 
  was 
  produced 
  by 
  charging 
  the 
  

   wire 
  to 
  a 
  fixed 
  potential 
  ( 
  + 
  80 
  volts), 
  using 
  a 
  battery 
  of 
  small 
  

   accumulators, 
  and 
  earthing 
  the 
  metal 
  cylinder. 
  

  

  The 
  emanation 
  was 
  introduced 
  into 
  the 
  cylinder 
  C 
  a& 
  

   follows. 
  The 
  taps 
  T 
  and 
  T' 
  were 
  opened 
  and 
  the 
  reservoir 
  K 
  

   was 
  raised 
  until 
  the 
  mercury 
  filled 
  the 
  tube 
  M 
  to 
  a 
  fixed 
  

   mark. 
  The 
  air 
  in 
  the 
  apparatus 
  was 
  then 
  at 
  atmospheric 
  

   pressure. 
  The 
  tap 
  T' 
  was 
  closed 
  and 
  K 
  lowered 
  a 
  fixed 
  

   distance. 
  After 
  the 
  expansion 
  had 
  ceased, 
  T 
  was 
  closed 
  and 
  

   K 
  raised 
  to 
  its 
  original 
  position. 
  This 
  compressed 
  the 
  air 
  in 
  

   M. 
  On 
  opening 
  T 
  a 
  sudden 
  rush 
  of 
  air 
  into 
  the 
  apparatus 
  

   occurred, 
  sufficient 
  to 
  carry 
  a 
  measurable 
  amount 
  of 
  the 
  

   emanation 
  past 
  the 
  glass-wool 
  plugs 
  in 
  H 
  and 
  past 
  a 
  cotton- 
  

   wool 
  plug 
  in 
  the 
  end 
  of 
  G 
  whose 
  purpose 
  was 
  to 
  free 
  the 
  

  

  