﻿Determination 
  of 
  Radium 
  in 
  Radioactive 
  Substances. 
  677 
  

  

  that 
  samarskite 
  gave 
  off 
  10 
  per 
  cent. 
  of 
  its 
  emanation 
  at 
  low 
  

   red 
  heat 
  (say 
  600° 
  C.) 
  and 
  20 
  per 
  cent, 
  at 
  bright 
  red 
  heat 
  

   (say 
  800° 
  C), 
  and 
  that 
  nraninite 
  gave 
  off 
  54 
  per 
  cent, 
  of: 
  its 
  

   emanation 
  at 
  bright 
  redness 
  are 
  in 
  accordance 
  with 
  the 
  above 
  

  

  Fig. 
  2. 
  

   ZSCAPZ 
  Of 
  RADIUM 
  EMANATION 
  

  

  from 
  Pitchblende. 
  

  

  « 
  

  

  100 
  

  

  ^> 
  

  

  

  1 
  

  

  30 
  

  

  1 
  

  

  80 
  

  

  $ 
  

  

  70 
  

  

  Q 
  

  

  

  s 
  

  

  60 
  

  

  T 
  

  

  

  ^ 
  

  

  

  & 
  50 
  

  

  <X) 
  

  

  

  3 
  

  

  40 
  

  

  Ui 
  

  

  

  

  30 
  

  

  20 
  

  

  I 
  

  

  10 
  

  

  ffl 
  

  

  4& 
  

  

  J234-5678S 
  1000 
  

   /EMP. 
  jn 
  HUAIOREDS 
  OF 
  DEGREES 
  CENT/G 
  ft/IDE 
  

  

  results. 
  Comparatively 
  large 
  differences 
  between 
  the 
  amounts 
  

   liberated 
  at 
  bright 
  redness 
  can 
  easily 
  be 
  accounted 
  for 
  at 
  this 
  

   region 
  o£ 
  the 
  curve. 
  Complete 
  de-emanation 
  takes 
  place 
  at 
  

   full 
  redness. 
  

  

  It 
  may 
  be 
  supposed 
  that 
  with 
  quantities 
  of 
  pitchblende 
  of 
  

   the 
  order 
  of 
  one 
  or 
  two 
  milligrams 
  the 
  escape 
  of 
  emanation 
  

   is 
  practically 
  instantaneous, 
  and 
  de-emanation 
  at 
  high 
  tem- 
  

   peratures 
  was 
  found 
  to 
  be 
  complete 
  in 
  a 
  few 
  seconds. 
  

  

  If 
  it 
  is 
  desired 
  to 
  investigate 
  solutions, 
  as 
  in 
  dealing 
  with 
  

   filtrates, 
  a 
  comparatively 
  large 
  amount 
  of 
  substance 
  may 
  be 
  

   dissolved 
  into 
  solution, 
  and 
  an 
  accurately 
  known 
  small 
  

   quantity 
  placed 
  on 
  the 
  carbon 
  by 
  means 
  of 
  a 
  capillary 
  

   pipette. 
  The 
  rod 
  is 
  then 
  examined 
  as 
  before 
  after 
  a 
  period 
  

   of 
  a 
  month. 
  

  

  I 
  am 
  much 
  indebted 
  to 
  Professor 
  G. 
  A. 
  J. 
  Cole 
  for 
  the 
  

   mineral 
  specimens, 
  and 
  to 
  Professor 
  Morgan 
  and 
  Dr. 
  Pollok 
  

   for 
  their 
  interest 
  in 
  the 
  work. 
  

  

  Royal 
  College 
  of 
  Science 
  for 
  Ireland, 
  

   Dublin, 
  June 
  1913. 
  

  

  Phil 
  Mag. 
  S. 
  6. 
  Vol. 
  26. 
  No. 
  154. 
  Oct. 
  1913. 
  2 
  Z 
  

  

  