﻿458 
  F. 
  A. 
  Gooch 
  and 
  T. 
  S. 
  Hart— 
  The 
  Detection, 
  etc. 
  

  

  Experiment 
  YII. 
  

  

  

  

  Part 
  I 
  

  

  

  1 
  

  

  Part 
  II. 
  

  

  I 
  

  

  

  Part 
  III. 
  

  

  is 
  

  

  ►1 
  

  

  O 
  

  

  ills* 
  

  

  Cj 
  o 
  * 
  o 
  S 
  

  

  Stronger 
  

   Stronger 
  

   j 
  Weaker 
  

   j 
  Like 
  

  

  A 
  

  

  5So 
  

  

  cS 
  O 
  » 
  

  

  o 
  

  

  ■©•a 
  

  

  0-18 
  mm. 
  

  

  0-80 
  '• 
  

   0-18 
  " 
  

   0-18 
  " 
  

  

  •*-> 
  ~ 
  a> 
  i* 
  

  

  la 
  11 
  

  

  cS-O 
  O 
  co 
  

   es 
  w 
  °5 
  

   OO 
  * 
  £ 
  

  

  Weaker 
  

  

  Weaker 
  

  

  Weaker 
  

  

  ( 
  Like 
  

  

  < 
  Stronger 
  

  

  ( 
  Stronger 
  

  

  Volume 
  of 
  

   test-solution. 
  

  

  O 
  

  

  Characteristic 
  

   of 
  potassium 
  

   line 
  as 
  com- 
  

   pared 
  with 
  

   standard. 
  

  

  30 
  cm. 
  3 
  

  

  0.23 
  mm. 
  

   0-23 
  " 
  

   0-23 
  " 
  

  

  0*05 
  grm.* 
  

   0-07 
  " 
  

   0-09 
  " 
  

   0-10 
  " 
  

  

  First. 
  

  

  90 
  " 
  

   100 
  " 
  

  

  100 
  cm. 
  3 
  

   120 
  " 
  

   130 
  " 
  

   140 
  " 
  

  

  023 
  mm. 
  

   0-23 
  " 
  

   023 
  " 
  

  

  023 
  " 
  

  

  Stronger 
  

  

  Stronger 
  

  

  Stronger 
  

  

  j 
  Stronger 
  

  

  } 
  Weaker 
  

  

  

  Second. 
  

  

  

  120 
  cm. 
  3 
  

   140 
  " 
  

  

  150 
  " 
  

  

  160 
  " 
  

  

  0-23 
  mm. 
  

   0-23 
  " 
  

  

  023 
  " 
  

  

  0-23 
  " 
  

  

  Stronger 
  

  

  Stronger 
  

  

  j 
  Stronger 
  

  

  ( 
  Weaker 
  

  

  Weaker 
  

  

  

  First. 
  Second. 
  

  

  (140x0.0001 
  = 
  0-0140) 
  (150x0-0001 
  = 
  0-0150) 
  

  

  Potassium 
  found 
  0-0180 
  grm. 
  0-0150 
  

  

  " 
  taken 
  0-0150 
  " 
  0*0150 
  

  

  Error 
  00010 
  " 
  = 
  7 
  per 
  cent 
  .0-0000 
  

  

  From 
  these 
  results 
  it 
  is 
  plain 
  that 
  the 
  sodium 
  in 
  test 
  and 
  

   standard 
  may 
  be 
  matched 
  closely 
  enough 
  to 
  allow 
  a 
  fair 
  approxi- 
  

   mation 
  to 
  be 
  made 
  in 
  the 
  determination 
  of 
  the 
  potassium. 
  In 
  

   Experiments 
  IV, 
  Y 
  and 
  VI, 
  no 
  readjustment 
  of 
  the 
  percentage 
  

   of 
  sodium 
  in 
  the 
  final 
  dilution, 
  subsequent 
  to 
  the 
  matching 
  of 
  

   the 
  sodium 
  lines, 
  was 
  attempted 
  ; 
  in 
  Experiment 
  YII 
  this 
  

   point 
  was 
  looked 
  to, 
  so 
  that 
  in 
  this 
  determination 
  the 
  strength 
  

   of 
  the 
  sodium 
  was 
  kept 
  equal 
  to 
  that 
  found 
  in 
  the 
  matching 
  

   process. 
  In 
  Experiments 
  IY 
  and 
  YII, 
  the 
  matching 
  of 
  the 
  

   sodium 
  in 
  the 
  test-solution 
  against 
  that 
  in 
  the 
  standard 
  proved 
  

   to 
  have 
  been 
  exact 
  ; 
  in 
  Y, 
  an 
  excess 
  of 
  10 
  per 
  cent 
  was 
  added, 
  

   and 
  in 
  YI, 
  the 
  point 
  of 
  equality 
  was 
  thought 
  to 
  have 
  been 
  

   reached 
  while 
  there 
  was 
  still 
  a 
  deficiency 
  of 
  25 
  per 
  cent 
  in 
  

   the 
  sodium 
  chloride 
  of 
  the 
  test-solution. 
  

  

  The 
  error 
  in 
  the 
  determination 
  of 
  the 
  potassium 
  in 
  Experi- 
  

   ment 
  YI 
  may, 
  perhaps, 
  be 
  accounted 
  for 
  by 
  the 
  mistake 
  in 
  

   matching 
  the 
  sodium 
  ; 
  that 
  of 
  the 
  first 
  attempt 
  in 
  Experiment 
  

   YII, 
  we 
  are 
  disposed 
  to 
  attribute 
  to 
  lack 
  of 
  care 
  in 
  keeping 
  

   the 
  eye 
  of 
  the 
  observer 
  in 
  the 
  most 
  sensitive 
  condition, 
  and 
  of 
  

   attention 
  to 
  the 
  point 
  of 
  bringing 
  the 
  wires 
  to 
  the 
  plane 
  in 
  

   quick 
  succession. 
  The 
  largest 
  absolute 
  error 
  met 
  with 
  amounted 
  

   to 
  one 
  milligram 
  in 
  a 
  total 
  of 
  fifteen. 
  Though 
  not 
  accurate 
  to 
  

  

  * 
  Originally 
  present. 
  

  

  