﻿142 
  Distribution 
  of 
  Thorium 
  in 
  the 
  Earth's 
  Surface. 
  

  

  replaced 
  by 
  one 
  on 
  a 
  mixed 
  sample 
  from 
  six 
  localities 
  which 
  

   since 
  preparation 
  had 
  been 
  stored 
  some 
  weeKs. 
  There 
  is, 
  

   I 
  think, 
  in 
  some 
  cases 
  an 
  increase 
  of 
  emanating 
  power 
  in 
  the 
  

   acid 
  solutions 
  which 
  are 
  kept 
  for 
  some 
  weeks 
  after 
  the 
  fusion 
  

   with 
  alkaline 
  carbonates. 
  All 
  the 
  tests 
  given 
  below 
  are 
  on 
  

   old 
  solutions. 
  

  

  Thorium 
  in 
  

   grams 
  per 
  gram. 
  

  

  Lava, 
  Vesuvius, 
  1906. 
  10 
  grams 
  2-6x10"^ 
  

  

  1895-99, 
  10 
  grams 
  2'1 
  „ 
  

  

  1832, 
  lOgrams 
  2'3 
  „ 
  

  

  1794, 
  10 
  grams 
  0-6 
  „ 
  

  

  1631, 
  10 
  grams 
  1-7 
  „ 
  

  

  „ 
  Etna, 
  1855, 
  10 
  grams 
  1-2 
  „ 
  

  

  „ 
  Pantellaria, 
  10 
  grams 
  2*2 
  ,, 
  

  

  „ 
  St 
  Helena, 
  10 
  grams 
  0-6 
  „ 
  

  

  Basalt, 
  Giant's 
  Causeway, 
  20 
  grams 
  0'9 
  „ 
  

  

  Gneiss, 
  Simplon 
  Tunnel, 
  10 
  grams 
  M 
  „ 
  

  

  Diabase, 
  Fit'eshire, 
  10 
  grams 
  less 
  than 
  0*2 
  „ 
  

  

  Shale, 
  Moffat 
  Dale, 
  10 
  grams 
  I'O 
  „ 
  

  

  Granite, 
  Co. 
  Wicklow, 
  20 
  grams 
  Tl 
  ,, 
  

  

  Carboniferous 
  Limestone, 
  Armagh, 
  22*5 
  grams 
  ... 
  less 
  than 
  0*2 
  „ 
  

  

  Marsupites 
  Chalk, 
  32 
  grams 
  less 
  than 
  0'6 
  ,, 
  

  

  Red 
  Clay, 
  N. 
  Pacific, 
  2'4 
  grams 
  less 
  than 
  0*9 
  „ 
  

  

  „ 
  Central 
  Pacific, 
  10 
  grams 
  O'-i 
  „ 
  

  

  Radiolarian 
  Ooze, 
  Central 
  Pacific, 
  6'3 
  grams 
  less 
  than 
  0*4 
  „ 
  

  

  Manganese 
  Nodule, 
  S, 
  Pacific, 
  12 
  grams 
  less 
  than 
  0'2 
  „ 
  

  

  Meteorite 
  fell 
  at 
  Dundrum, 
  25'6 
  grams 
  0*09 
  „ 
  

  

  Sea- 
  Water, 
  Coast 
  of 
  Dublin, 
  1400 
  CCS 
  less 
  than 
  l-4xl0-8 
  

  

  ,, 
  S. 
  Atlantic, 
  1790 
  CCS 
  less 
  than 
  1*1 
  ,, 
  

  

  „ 
  „ 
  1500 
  CCS 
  less 
  than 
  1'4 
  ,, 
  

  

  Lidian 
  Ocean, 
  2800 
  CCS 
  09 
  „ 
  

  

  In 
  giving 
  these 
  results 
  in 
  the 
  Phil. 
  Mng. 
  for 
  May 
  I 
  regret 
  

   that 
  1 
  was 
  unaware 
  of 
  M. 
  Blanc's 
  important 
  contributions 
  to 
  

   the 
  same 
  subject. 
  M. 
  Blanc 
  has 
  been 
  so 
  kind 
  as 
  to 
  send 
  

   me 
  an 
  account 
  of 
  his 
  results 
  w^hich 
  appears 
  in 
  this 
  present 
  

   number. 
  

  

  The 
  determination 
  of 
  thorium 
  in 
  the 
  meteorite 
  which 
  fell 
  

   at 
  Dundrum, 
  i)o. 
  Tipperarj, 
  seems 
  quite 
  certain 
  although 
  

   the 
  quantity 
  present 
  is 
  small. 
  Two 
  prolonged 
  experiments 
  

   gave 
  an 
  identical 
  result 
  of 
  a 
  steady 
  gain 
  of 
  little 
  over 
  one 
  

   scale-division 
  per 
  hour 
  This 
  meteorite 
  is 
  partly 
  nickel-iron, 
  

   but 
  for 
  the 
  greater 
  part, 
  about 
  75 
  per 
  cent., 
  consists 
  of 
  non- 
  

   metallic 
  minerals. 
  

  

  The 
  Rocks 
  of 
  the 
  St. 
  Gothard 
  Tunnel. 
  

  

  The 
  experiments 
  which 
  I 
  had 
  previously 
  made 
  upon 
  the 
  

   radium 
  content 
  of 
  the 
  rocks 
  of 
  the 
  St. 
  Gothard 
  tunnel 
  

   (Address 
  to 
  Section 
  C, 
  British 
  Association, 
  1908) 
  left 
  me 
  in 
  

   possession 
  of 
  solutions 
  of 
  51 
  rocks. 
  These 
  rocks 
  had 
  been 
  

   selected 
  so 
  as 
  to 
  be 
  as 
  far 
  as 
  possible 
  typical 
  of 
  the 
  principal 
  

  

  