﻿258 
  Conductivity 
  of 
  Dielectrics 
  under 
  Radium 
  Rays. 
  

  

  conductivity 
  increased. 
  This 
  is 
  shown 
  in 
  the 
  case 
  o£ 
  paraffin 
  

   and 
  vaseline 
  in 
  Table 
  III. 
  

  

  Table 
  III. 
  

  

  Vaseline. 
  

   Time 
  

  

  Current 
  (10-12 
  amp.) 
  

  

  Radium 
  

  

  Heavy 
  Faraffin 
  Oil. 
  

   Time 
  

  

  Current 
  (10—13 
  amp.) 
  

  

  Radium 
  , 
  

  

  10.36 
  

   1-8 
  

   out 
  

  

  10.52 
  

  

  1-8 
  

  

  out 
  

  

  11.18 
  

  

  2-2 
  

   in 
  

  

  12.46 
  3.58 
  

   3-5 
  4-9 
  

  

  in 
  in 
  

  

  10.30 
  10.47 
  11.18 
  11.48 
  12.18 
  12.36 
  12.55 
  

   4-8 
  12-4 
  17-0 
  17-4 
  17-8 
  18-2 
  19-1 
  

   out 
  in 
  in 
  in 
  in 
  in 
  in 
  

  

  riff. 
  7. 
  

  

  16 
  

  

  T 
  

  

  

  ,^---®-- 
  

  

  '-(^- 
  

  

  -©-- 
  

  

  --(S 
  

  

  G^ 
  

  

  

  

  f 
  

   I 
  

  

  //£/9l^y 
  P/}f?/?FF/A/ 
  

  

  //V 
  0/L 
  

  

  1 
  

  

  1 
  

   (p) 
  

  

  

  

  

  

  

  I 
  hours 
  

  

  The 
  curves 
  obtained, 
  showing 
  the 
  behaviour 
  of 
  dielectrics 
  

   under 
  the 
  action 
  o£ 
  radium 
  rays, 
  are 
  similar 
  in 
  character 
  to 
  

   those 
  obtained 
  by 
  JafEe 
  with 
  very 
  pure 
  substances. 
  The 
  

   immediate 
  increase 
  due 
  to 
  radiation 
  was 
  observed 
  in 
  benzene, 
  

   toluene, 
  aniline, 
  and 
  carbon 
  disulphide, 
  in 
  addition 
  to 
  those 
  

   mentioned 
  above. 
  The 
  vaseline 
  used 
  was 
  the 
  unpurified 
  

   commercial 
  sort, 
  and 
  it 
  was 
  rather 
  irregular 
  in 
  its 
  action. 
  

   Its 
  conductivity 
  proper 
  decreased 
  very 
  rapidly, 
  so 
  much 
  so 
  

   as 
  to 
  mask 
  completely 
  the 
  increase 
  due 
  to 
  radiation, 
  i£ 
  

   sufficient 
  time 
  was 
  not 
  allowed 
  to 
  elapse 
  to 
  produce 
  its 
  own 
  

   minimum 
  conductivity. 
  

  

  These 
  experiments 
  have 
  been 
  conducted 
  in 
  the 
  Physical 
  

   Laboratory 
  of 
  Armstrong 
  College, 
  Newcastle-on-Tyne, 
  under 
  

   Prof. 
  H. 
  Stroud 
  and 
  Mr. 
  fl. 
  Morris-Airey, 
  to 
  whom 
  my 
  best 
  

   thanks 
  are 
  due. 
  

  

  