﻿308 
  

  

  Prof. 
  E. 
  Rutherford 
  : 
  Experiments 
  

  

  was 
  prominent. 
  In 
  addition 
  to 
  the 
  mercury 
  lines, 
  a 
  few 
  

   others 
  were 
  observed 
  which 
  were 
  not 
  identified 
  with 
  cer- 
  

   tainty. 
  The 
  initial 
  volume, 
  0*154 
  c.mm., 
  corresponded 
  to 
  

   67 
  mgs. 
  radium, 
  consequently 
  the 
  initial 
  volume 
  correspond- 
  

   ing 
  to 
  one 
  gram 
  of 
  radium 
  was 
  2*3 
  c.mm. 
  The 
  final 
  volume 
  

   after 
  21 
  hours 
  corresponds 
  to 
  5*2 
  c.mm. 
  per 
  gram. 
  As 
  the 
  

   spectrum 
  indicated, 
  the 
  emanation 
  in 
  this 
  case 
  was 
  very 
  

   impure, 
  containing 
  probably 
  a 
  large 
  proportion 
  of 
  CO 
  or 
  Q0 
  2 
  . 
  

  

  Experiment 
  II. 
  — 
  We 
  shall 
  now 
  give 
  an 
  example 
  of 
  the 
  

   contraction 
  of 
  volume. 
  In 
  this 
  case 
  the 
  emanation 
  was 
  far 
  

   purer 
  than 
  in 
  experiment 
  I. 
  The 
  emanation 
  was 
  left 
  four 
  

   hours 
  in 
  the 
  presence 
  of 
  caustic 
  potash 
  before 
  introduction 
  

   into 
  the 
  capillary. 
  The 
  amount 
  of 
  emanation 
  in 
  the 
  capillary 
  

   corresponded 
  to 
  130 
  mgs. 
  radium. 
  

  

  Time 
  after 
  introduction 
  

  

  Volume 
  of 
  gas 
  in 
  capillary 
  

  

  of 
  the 
  emanation 
  into 
  

  

  at 
  normal 
  pressure 
  and 
  

  

  capillary. 
  

  

  room 
  temperature. 
  

  

  2 
  minutes 
  

  

  0*171 
  c.mm. 
  

  

  5 
  

  

  •169 
  „ 
  

  

  o 
  

  

  •165 
  „ 
  

  

  18 
  

  

  •158 
  „ 
  

  

  26 
  „ 
  

  

  •150 
  „ 
  

  

  37 
  ,, 
  

  

  •135 
  „ 
  

  

  56 
  

  

  •126 
  „ 
  

  

  70 
  „ 
  

  

  •120 
  ., 
  

  

  91 
  

  

  •106 
  „ 
  

  

  5 
  "9 
  hours 
  

  

  •097 
  „ 
  

  

  17 
  „ 
  

  

  •069 
  „ 
  

  

  44 
  

  

  •075 
  ,. 
  

  

  92 
  

  

  •079 
  „ 
  

  

  161 
  

  

  •080 
  „ 
  

  

  185 
  

  

  •119 
  „ 
  

  

  209 
  

  

  •125 
  ,. 
  

  

  257 
  

  

  •125 
  „ 
  

  

  The 
  initial 
  volume 
  for 
  the 
  emanation 
  from 
  one 
  gram 
  of 
  

   radium 
  corresponded 
  to 
  1*32 
  c.mm. 
  Correcting 
  for 
  the 
  

   decay 
  of 
  the 
  emanation, 
  the 
  volume 
  at 
  the 
  minimum 
  after 
  

   an 
  interval 
  of 
  17 
  hours 
  was 
  equal 
  to 
  59 
  c.mm. 
  per 
  gram 
  of 
  

   radium. 
  It 
  will 
  be 
  observed 
  that 
  the 
  volume 
  sank 
  to 
  about 
  

   0*4 
  of 
  its 
  initial 
  value 
  after 
  17 
  hours. 
  After 
  passing 
  through 
  

   a 
  minimum, 
  the 
  volume 
  increased 
  again, 
  though 
  not 
  very 
  

   regularly. 
  At 
  the 
  conclusion 
  of 
  the 
  experiment, 
  L 
  e. 
  after 
  

  

  