﻿of 
  Antimony 
  and 
  its 
  condition 
  of 
  Oxidation. 
  217 
  

  

  in 
  treating 
  the 
  larger 
  amounts. 
  The 
  only 
  point 
  in 
  which 
  

   these 
  experiments 
  differ 
  essentially 
  from 
  those 
  of 
  the 
  previous 
  

   series 
  is 
  in 
  the 
  quantity 
  of 
  the 
  iodine 
  solution 
  employed 
  to 
  

   effect 
  this 
  oxidation. 
  So 
  far 
  as 
  concerns 
  the 
  free 
  iodine 
  itself 
  

   the 
  conditions 
  are 
  similar 
  in 
  both 
  series 
  ; 
  for 
  the 
  iodine 
  is 
  con- 
  

   verted 
  in 
  both 
  cases 
  to 
  hydriodic 
  acid 
  exactly 
  equivalent 
  in 
  

   amount 
  to 
  the 
  antimony 
  acted 
  upon. 
  The 
  potassium 
  iodide 
  

   which 
  is 
  added 
  in 
  the 
  iodine 
  solution 
  produces 
  by 
  action 
  upon 
  

   the 
  sulphuric 
  acid 
  present 
  an 
  excess 
  of 
  hydriodic 
  acid, 
  which 
  

   is, 
  of 
  course, 
  dependent 
  upon 
  the 
  absolute 
  amount 
  of 
  the 
  

   iodine 
  solution 
  employed. 
  The 
  hydriodic 
  acid 
  is 
  the 
  active 
  

   agent 
  in 
  the 
  reduction 
  of 
  the 
  antimony, 
  and 
  to 
  the 
  greater 
  

   mass-action 
  in 
  the 
  former 
  series 
  of 
  experiments 
  might 
  be 
  

   attributed 
  the 
  more 
  complete 
  reduction 
  for 
  equal 
  degrees 
  of 
  

   concentration. 
  Accordingly 
  the 
  determinations 
  of 
  Table 
  III 
  

   were 
  made 
  to 
  put 
  this 
  point 
  to 
  the 
  test. 
  In 
  these 
  experiments 
  

   the 
  conditions 
  were 
  identical 
  with 
  those 
  of 
  the 
  determinations 
  

   of 
  Table 
  II, 
  excepting 
  that 
  in 
  every 
  case 
  1 
  grm. 
  of 
  potassium 
  

   iodide 
  was 
  added 
  to 
  the 
  liquid 
  before 
  boiling, 
  thus 
  bringing 
  

   the 
  total 
  amount 
  of 
  hydriodic 
  acid 
  present 
  to 
  an 
  equality 
  with 
  

   that 
  present 
  in 
  the 
  experiments 
  of 
  Table 
  I, 
  in 
  which 
  the 
  larger 
  

   amounts 
  of 
  antimony 
  were 
  treated. 
  The 
  results 
  of 
  these 
  

   experiments 
  bear 
  out 
  completely 
  the 
  hypothesis 
  concerning 
  

   the 
  mass-action 
  of 
  the 
  hydriodic 
  acid 
  — 
  the 
  smaller 
  amounts 
  of 
  

   antimony 
  being 
  completely 
  reduced 
  in 
  the 
  presence 
  of 
  the 
  

   large 
  excess 
  of 
  hydriodic 
  acid 
  even 
  at 
  a 
  final 
  volume 
  of 
  60 
  cm. 
  3 
  

   with 
  a 
  maximum 
  error 
  of 
  0*0002 
  grm. 
  — 
  

  

  Table 
  III. 
  

  

  Tartar 
  

  

  Final 
  Emetic 
  

  

  Volume. 
  taken. 
  

  

  Sb 
  2 
  3 
  Iodine 
  used 
  

  

  in 
  final 
  

   taken. 
  oxidation. 
  

  

  Sb 
  2 
  3 
  

   found. 
  

  

  Error. 
  

  

  cm. 
  3 
  grm. 
  

   60 
  0-0500 
  

   60 
  0-0500 
  

   60 
  0-0500 
  

  

  grm. 
  grm. 
  

   0-0217 
  00378 
  

   00217 
  0-0379 
  

   00217 
  0-0379 
  

  

  grm. 
  

  

  0-0215 
  

   0-0216 
  

   0-0216 
  

  

  grm. 
  

   0-0002 
  — 
  

  

  o-oooi- 
  

   o-oooi- 
  

  

  It 
  is 
  plain 
  therefore 
  that 
  we 
  have 
  in 
  the 
  phenomena 
  de- 
  

   scribed 
  the 
  basis 
  of 
  a 
  good 
  method 
  for 
  the 
  iodometric 
  deter- 
  

   mination 
  of 
  the 
  condition 
  of 
  oxidation 
  of 
  antimony; 
  for, 
  the 
  

   amount 
  of 
  antimonious 
  salt 
  present 
  in 
  a 
  mixture 
  of 
  antimoni- 
  

   ous 
  and 
  antimonic 
  salts 
  may 
  be 
  determined 
  by 
  direct 
  titration 
  

   in 
  alkaline 
  solution, 
  and 
  the 
  total 
  amount 
  of 
  antimony 
  present 
  

   is 
  given 
  similarly 
  after 
  the 
  treatment 
  by 
  boiling, 
  as 
  described, 
  

   with 
  potassium 
  iodide 
  and 
  sulphuric 
  acid, 
  the 
  amount 
  of 
  

   antimonic 
  salt 
  being 
  immediately 
  calculable 
  from 
  the 
  difference 
  

   between 
  the 
  quantities 
  of 
  the 
  standard 
  iodine 
  used 
  as 
  the 
  

  

  