﻿Radium 
  present 
  in 
  Sea- 
  Water. 
  103 
  

  

  sea-water 
  collected 
  from 
  mid 
  -Atlantic, 
  and 
  found 
  0*3 
  and 
  0*6, 
  

   respectively, 
  expressed 
  in 
  the 
  above 
  units. 
  

  

  A 
  large 
  number 
  of 
  samples 
  have 
  been 
  examined 
  by 
  Joly, 
  

   and 
  in 
  his 
  Presidential 
  Address 
  to 
  the 
  British 
  Association, 
  

   1908, 
  he 
  stated 
  that 
  the 
  average 
  value 
  found 
  by 
  him 
  was 
  16. 
  

  

  These 
  three 
  observers 
  then 
  give 
  results 
  in 
  the 
  ratios 
  of 
  

   4,1,27. 
  

  

  There 
  are 
  several 
  points 
  of 
  special 
  interest 
  in 
  Joly's 
  paper 
  *. 
  

   In 
  the 
  tirst 
  place 
  he 
  found 
  that 
  the 
  addition 
  of 
  HCl 
  tended 
  

   sometimes 
  to 
  increase 
  the 
  amount 
  of 
  radium 
  determined 
  by 
  

   his 
  experimental 
  method, 
  apparently 
  through 
  clearing 
  away 
  

   pi-ecipitates, 
  possibly 
  of 
  sulphates. 
  Next, 
  a 
  second 
  deter- 
  

   mination 
  invariably 
  afforded 
  a 
  higher 
  reading 
  than 
  the 
  first. 
  

   Thirdly, 
  two 
  vsamples 
  of 
  sea-water 
  which 
  had 
  stood 
  for 
  two 
  

   months 
  in 
  bottles, 
  before 
  testing, 
  gave 
  low 
  values. 
  

  

  I 
  venture 
  to 
  give 
  a 
  brief 
  summary 
  of 
  the 
  results 
  published 
  

   by 
  Joly. 
  

  

  Samples 
  of 
  Sea-vrnter 
  collected 
  near 
  land. 
  

  

  Without 
  HOI. 
  With 
  HCl. 
  

   a. 
  Valencia 
  Harbour 
  ^5-6 
  40*0 
  

  

  h. 
  Few 
  miles 
  W. 
  of 
  I. 
  of 
  Man 
  3-8 
  38-6 
  

  

  c. 
  65 
  miles 
  W. 
  of 
  Valencia 
  12-6 
  31*4 
  

  

  d. 
  1-5 
  miles 
  S. 
  of 
  Crow 
  Head, 
  Co. 
  Kerry, 
  15-2 
  22-6 
  

  

  e. 
  20 
  miles 
  W. 
  of 
  Bantry 
  Bay 
  268 
  39-3 
  

  

  Samples 
  from 
  Ocean 
  between 
  Madeira 
  and 
  Bay 
  of 
  Biscay. 
  

  

  Without 
  HCl. 
  With 
  HCl. 
  

   /, 
  2-9 
  14-4 
  

  

  ./; 
  1^-0, 
  21-3 
  

  

  <j, 
  . 
  . 
  19-3, 
  27-3 
  

  

  V. 
  4-4, 
  8-0 
  

  

  h^ 
  . 
  . 
  2-0, 
  14-6 
  

  

  h^_ 
  . 
  . 
  8-4 
  

  

  i, 
  3-5 
  26-0 
  

  

  i., 
  . 
  . 
  30-4 
  

  

  J, 
  14-6 
  

  

  Arabian 
  Sea. 
  

   Jc 
  . 
  . 
  24-3, 
  31-4 
  

  

  27-8 
  

  

  The 
  range 
  is 
  from 
  about 
  8 
  to 
  40, 
  and 
  the 
  average 
  value 
  

   of 
  all 
  Professor 
  Joly's 
  determinations 
  is 
  16. 
  

  

  * 
  Phil. 
  Mag. 
  vol. 
  xv. 
  pp. 
  385-393 
  (March 
  1908). 
  

  

  