﻿Radium- 
  Content 
  of 
  Deep- 
  Sea 
  Sediments. 
  191 
  

  

  merits. 
  A 
  short 
  list 
  has 
  to 
  be 
  given, 
  however, 
  of 
  such 
  as 
  have 
  

   been 
  used 
  in 
  obtaining 
  the 
  data 
  which 
  follow. 
  A 
  reference 
  

   letter 
  attached 
  to 
  the 
  experiment 
  will 
  then 
  suffice 
  to 
  show 
  the 
  

   mode 
  of 
  extraction 
  adopted. 
  

  

  (A.) 
  The 
  substance 
  is 
  fused 
  in 
  a 
  platinum 
  crucible 
  with 
  

   the 
  mixed 
  carbonates 
  of 
  sodium 
  and 
  potassium, 
  and 
  the 
  melt 
  

   leached 
  in 
  hot 
  water. 
  This 
  is 
  filtered, 
  and 
  the 
  filtrate 
  is 
  closed 
  

   as 
  the 
  alkaline 
  solution. 
  The 
  residue 
  is 
  treated 
  with 
  hydro- 
  

   chloric 
  acid, 
  and 
  closed 
  as 
  the 
  acid 
  solution. 
  If 
  the 
  acid 
  

   solution 
  contains 
  or 
  develops 
  a 
  precipitate, 
  this 
  is 
  filtered 
  out 
  

   and 
  re-fused 
  with 
  the 
  carbonates, 
  the 
  melt 
  being 
  treated 
  as 
  

   before, 
  i. 
  e. 
  divided 
  between 
  the 
  alkaline 
  and 
  the 
  acid 
  solutions. 
  

   Both 
  solutions 
  are 
  subsequently 
  examined 
  for 
  radium. 
  In 
  a 
  

   variation 
  of 
  this 
  method 
  the 
  melt 
  after 
  leaching 
  is 
  acidified, 
  

   and 
  but 
  one 
  acid 
  solution 
  closed. 
  

  

  (B.) 
  The 
  substance 
  is 
  boiled 
  in 
  HC1, 
  and 
  the 
  filtered 
  solu- 
  

   tion 
  enclosed 
  the 
  requisite 
  time. 
  This 
  is 
  applicable 
  only 
  

   when 
  there 
  is 
  good 
  reason 
  to 
  believe 
  that 
  the 
  insoluble 
  part 
  

   contains 
  but 
  little 
  radium. 
  

  

  (C.) 
  The 
  substance 
  is 
  fused 
  with 
  the 
  carbonates, 
  and 
  the 
  

   leaching 
  effected 
  as 
  in 
  (A). 
  The 
  thoroughly 
  softened 
  and 
  

   diffused 
  melt 
  and 
  solution 
  are 
  enclosed 
  in 
  the 
  one 
  flask 
  with- 
  

   out 
  further 
  treatment. 
  After 
  the 
  lapse 
  of 
  the 
  requisite 
  period 
  

   it 
  is 
  attacked 
  with 
  HC1, 
  and 
  the 
  emanation 
  withdrawn 
  along 
  

   with 
  the 
  C0 
  2 
  evolved 
  in 
  the 
  process 
  of 
  decomposition. 
  

   Vigorous 
  boiling 
  finishes 
  the 
  process 
  of 
  extraction. 
  The 
  

   arrangement 
  of 
  apparatus 
  is 
  such 
  as 
  to 
  secure 
  the 
  absorption 
  

   of 
  the 
  C0 
  2 
  , 
  the 
  air 
  and 
  emanation 
  only 
  being 
  transferred 
  to 
  

   the 
  electroscope. 
  This 
  is 
  a 
  very 
  effective 
  method 
  where 
  the 
  

   attack 
  with 
  acid 
  secures 
  complete 
  solution. 
  

  

  (D.) 
  The 
  substance 
  in 
  the 
  form 
  of 
  a 
  fine 
  powder 
  is 
  placed 
  

   in 
  a 
  small 
  flask, 
  and 
  acid 
  run 
  in 
  upon 
  it, 
  the 
  remainder 
  of 
  the 
  

   treatment 
  being 
  as 
  in 
  method 
  (C). 
  It 
  is, 
  of 
  course, 
  only 
  

   applicable 
  to 
  carbonates, 
  or 
  soluble 
  substances 
  like 
  manganese 
  

   dioxide, 
  calcium 
  sulphate, 
  &c. 
  

  

  (E.) 
  The 
  substance 
  is 
  enclosed 
  in 
  a 
  very 
  thin 
  blown 
  glass 
  

   bulb, 
  wdiich 
  is 
  sealed 
  by 
  the 
  blowpipe. 
  This 
  is 
  preserved 
  for 
  

   about 
  twenty 
  days. 
  The 
  bulb 
  is 
  then 
  placed 
  in 
  a 
  flask, 
  and 
  

   after 
  this 
  is 
  attached 
  to 
  the 
  train 
  of 
  receiving 
  apparatus, 
  the 
  

   bulb 
  is 
  broken 
  by 
  shaking 
  the 
  flask. 
  Acid 
  is 
  then 
  run 
  in, 
  

   and 
  the 
  process 
  proceeds 
  as 
  in 
  (D). 
  The 
  object 
  here 
  is 
  to 
  

   correct 
  the 
  loss 
  w^hich 
  attends 
  the 
  direct 
  treatment 
  of 
  powders 
  

   owing 
  to 
  the 
  large 
  surface 
  and 
  consequent 
  escape 
  of 
  emana- 
  

   tion. 
  This 
  loss 
  is 
  shown 
  in 
  experiment 
  (2) 
  on 
  the 
  Globigerina 
  

   Ooze, 
  from 
  the 
  ' 
  Albatross 
  ' 
  collection, 
  when 
  compared 
  with 
  

   experiment 
  (1) 
  on 
  the 
  same 
  material. 
  

  

  