﻿456 
  F. 
  A. 
  Gooch 
  and 
  T. 
  S. 
  Hart 
  — 
  The 
  Detection 
  and 
  

  

  From 
  this 
  it 
  appears 
  that 
  the 
  maximum 
  strengthening 
  effect 
  

   occurs 
  when 
  the 
  sodium 
  chloride 
  stands 
  to 
  the 
  potassium 
  in 
  

   the 
  ratio 
  of 
  100 
  : 
  1. 
  The 
  apparent 
  diminution 
  of 
  brilliance 
  

   when 
  the 
  sodium 
  is 
  increased 
  beyond 
  that 
  proportion 
  is 
  doubt- 
  

   less 
  due 
  to 
  the 
  effect 
  of 
  the 
  strong 
  light 
  diffused 
  through 
  the 
  

   field 
  of 
  view 
  by 
  the 
  intensely 
  bright 
  sodium 
  flame 
  in 
  spite 
  of 
  

   the 
  fact 
  that 
  the 
  line 
  itself 
  is 
  cut 
  off 
  from 
  direct 
  vision. 
  

  

  The 
  cause 
  of 
  the 
  brightening 
  effect 
  of 
  the 
  sodium 
  chloride 
  

   we 
  are 
  inclined 
  to 
  attribute 
  to 
  the 
  chemical 
  action 
  of 
  the 
  sodium 
  

   dissociated 
  in 
  the 
  flame. 
  The 
  effect 
  of 
  ammonium 
  chloride, 
  

   and 
  of 
  hydrochloric 
  acid, 
  in 
  destroying 
  the 
  potassium 
  light 
  is 
  

   well 
  known, 
  and 
  is 
  due, 
  presumably, 
  in 
  very 
  large 
  degree 
  to 
  

   the 
  prevention 
  of 
  the 
  dissociation 
  of 
  the 
  potassium 
  chloride. 
  

   The 
  dissociated 
  sodium 
  should 
  naturally 
  by 
  its 
  mass-action 
  

   reinforce 
  the 
  disintegrating 
  action 
  of 
  the 
  heat 
  upon 
  the 
  mole- 
  

   cule 
  of 
  potassium 
  chloride. 
  

  

  It 
  is 
  plain 
  that 
  the 
  complication 
  introduced 
  into 
  the 
  quanti- 
  

   tative 
  spectroscopic 
  determination 
  of 
  potassium 
  by 
  the 
  presence 
  

   of 
  the 
  sodium 
  salt 
  in 
  the 
  test 
  can 
  be 
  obviated 
  if 
  it 
  can 
  be 
  

   brought 
  about 
  that 
  both 
  the 
  test 
  and 
  the 
  standard 
  solution 
  shall 
  

   contain 
  the 
  same 
  amount 
  of 
  that 
  reagent. 
  It 
  is 
  a 
  matter 
  of 
  

   interest, 
  therefore, 
  to 
  discover 
  whether 
  it 
  is 
  possible 
  to 
  match 
  

   sodium 
  lines 
  of 
  considerable 
  intensity 
  so 
  closely 
  that 
  the 
  quan- 
  

   tities 
  of 
  that 
  element 
  in 
  solutions 
  brought 
  into 
  comparison 
  shall 
  

   be 
  practically 
  equal, 
  and 
  so 
  may 
  be 
  relied 
  upon 
  to 
  give 
  the 
  

   same 
  strengthening 
  effect 
  to 
  the 
  potassium 
  spectrum. 
  The 
  

   following 
  statement 
  is 
  the 
  record 
  of 
  an 
  attempt 
  in 
  this 
  direc- 
  

   tion. 
  The 
  narrower 
  slit 
  was 
  found 
  to 
  be 
  best 
  adopted 
  to 
  the 
  

   comparison 
  of 
  the 
  sodium 
  lines. 
  

  

  

  

  

  Characteristic 
  of 
  line 
  as 
  

  

  NaCl 
  in 
  a 
  coil-full 
  

  

  NaCl 
  in 
  a 
  coil 
  full 
  

  

  Width 
  of 
  

  

  compared 
  with 
  that 
  of 
  

  

  of 
  new 
  solution. 
  

  

  of 
  standard. 
  

  

  slit. 
  

  

  standard. 
  

  

  0-010 
  mg. 
  

  

  02 
  mg. 
  

  

  0-18 
  mm. 
  

  

  weaker. 
  

  

  0-017 
  " 
  

  

  0-02 
  " 
  

  

  0-18 
  " 
  

  

  weaker. 
  

  

  0019 
  " 
  

  

  0-02 
  " 
  

  

  0-18 
  " 
  

  

  weaker. 
  

  

  0-020 
  " 
  

  

  0-02 
  " 
  

  

  0-18 
  " 
  

  

  like. 
  

  

  The 
  result 
  shows 
  the 
  possibility 
  of 
  matching 
  the 
  sodium 
  

   lines 
  with 
  a 
  degree 
  of 
  approximation 
  sufficient 
  for 
  the 
  purpose 
  

   in 
  view 
  ; 
  and, 
  accordingly, 
  a 
  new 
  standard 
  solution 
  was 
  made 
  

   containing 
  0*01 
  grm. 
  of 
  potassium 
  taken 
  in 
  the 
  form 
  of 
  the 
  

   chloride 
  and 
  0'1 
  grm. 
  of 
  sodium 
  chloride 
  in 
  100 
  cm 
  3 
  , 
  and 
  with 
  

   this 
  new 
  standard 
  the 
  following 
  determinations 
  were 
  made. 
  

   The 
  experiment 
  was 
  performed 
  in 
  three 
  stages 
  : 
  first, 
  the 
  test 
  

   solution 
  was 
  diluted 
  until 
  its 
  potassium 
  line 
  matched 
  approxi- 
  

   mately 
  with 
  that 
  of 
  the 
  standard 
  ; 
  secondly, 
  sodium 
  chloride 
  

   was 
  added 
  to 
  the 
  solution 
  thus 
  diluted 
  until 
  the 
  sodium 
  lines 
  

   were 
  brought 
  to 
  equality; 
  and, 
  finally, 
  the 
  test 
  solution 
  and 
  

   the 
  standard 
  were 
  again 
  brought 
  into 
  comparison. 
  

  

  