﻿Separation 
  of 
  Antimony 
  from 
  Arsenic. 
  309 
  

  

  (added 
  in 
  the 
  form 
  of 
  tartar 
  emetic) 
  was 
  retained 
  entirely 
  in 
  

   the 
  residue 
  under 
  similar 
  conditions 
  of 
  treatment. 
  Moreover, 
  

   it 
  appeared 
  that 
  this 
  action 
  could 
  be 
  brought 
  about 
  in 
  solutions 
  

   measuring 
  no 
  more 
  than 
  100 
  cm. 
  3 
  at 
  the 
  beginning 
  and 
  no 
  less 
  

   than 
  50 
  cm. 
  3 
  at 
  the 
  end 
  of 
  the 
  distillation, 
  so 
  that 
  a 
  very 
  

   considerable 
  saving 
  of 
  time 
  over 
  that 
  demanded 
  by 
  the 
  process 
  

   of 
  distillation 
  as 
  left 
  by 
  Classen 
  and 
  Ludwig 
  could 
  be 
  effected. 
  

   Accordingly 
  we 
  proceeded 
  to 
  test 
  the 
  action 
  of 
  the 
  hydriodic 
  

   acid 
  quantitatively, 
  following 
  the 
  same 
  general 
  lines. 
  The 
  

   distillation-apparatus 
  consisted 
  of 
  a 
  flask 
  of 
  250 
  cm. 
  3 
  capacity, 
  

   provided 
  with 
  a 
  hollow 
  glass 
  stopper 
  tightly 
  fitted 
  in 
  a 
  ground 
  

   joint, 
  the 
  stopper 
  itself 
  being 
  sealed 
  upon 
  a 
  large 
  glass 
  tube 
  

   bent 
  suitably 
  to 
  connect 
  the 
  interior 
  of 
  the 
  flask 
  with 
  an 
  

   upright 
  condenser, 
  while 
  through 
  the 
  hollow 
  stopper, 
  and 
  

   sealed 
  into 
  it, 
  passed 
  a 
  smaller 
  glass 
  tube 
  reaching 
  nearly 
  to 
  

   the 
  bottom 
  of 
  the 
  flask. 
  The 
  arrangement 
  was 
  such 
  that 
  a 
  

   current 
  of 
  gas 
  entering 
  the 
  smaller 
  tube 
  would 
  pass 
  nearly 
  to 
  

   the 
  bottom 
  of 
  the 
  flask 
  and 
  then 
  out 
  through 
  the 
  hollow 
  stop- 
  

   per 
  into 
  the 
  condenser 
  without 
  meeting 
  joints 
  of 
  rubber 
  or 
  

   cork. 
  Into 
  this 
  flask 
  was 
  weighed, 
  for 
  the 
  experiments 
  of 
  

   Table 
  I, 
  about 
  a 
  half 
  gram 
  of 
  carefully 
  recrystallized 
  tartar 
  

   emetic, 
  and 
  a 
  half' 
  gram 
  of 
  pure 
  di-hydrogen 
  potassium 
  

   arseniate 
  and 
  a 
  gram 
  of 
  potassium 
  iodide 
  were 
  added 
  in 
  

   concentrated 
  solution, 
  the 
  volume 
  of 
  liquid 
  being 
  made 
  up 
  to 
  

   100 
  cm. 
  3 
  by 
  the 
  addition 
  of 
  strong 
  hydrochloric 
  acid. 
  A 
  brisk 
  

   current 
  of 
  hydrochloric 
  acid 
  gas 
  was 
  passed 
  into 
  the 
  solution 
  

   through 
  the 
  tube 
  sealed 
  into 
  the 
  glass 
  stopper 
  of 
  the 
  flask 
  

   until 
  complete 
  saturation 
  was 
  effected, 
  and 
  then 
  the 
  liquid 
  was 
  

   heated 
  and 
  distilled 
  in 
  the 
  continuous 
  current 
  of 
  hydrochloric 
  

   acid 
  gas 
  until 
  the 
  volume 
  of 
  30 
  cm. 
  3 
  was 
  reached. 
  Iodine 
  was 
  

   evolved 
  as 
  soon 
  as 
  the 
  liquid 
  became 
  warm 
  and 
  the 
  greater 
  

   part 
  of 
  it 
  passed 
  into 
  the 
  distillate 
  with 
  the 
  first 
  10 
  cm. 
  3 
  

   When 
  the 
  final 
  concentration 
  was 
  reached 
  the 
  solution 
  was 
  in 
  

   each 
  case 
  colorless, 
  but 
  on 
  cooling 
  there 
  appeared 
  in 
  one 
  of 
  

   the 
  two 
  experiments 
  of 
  this 
  set 
  a 
  pale 
  yellow 
  tint 
  which 
  van- 
  

   ished 
  with 
  the 
  dilution 
  involved 
  in 
  the 
  transfer 
  and 
  washing 
  

   from 
  the 
  flask 
  previous 
  to 
  titration. 
  The 
  addition 
  of 
  starch 
  to 
  

   the 
  cooled 
  and 
  diluted 
  liquid 
  developed 
  no 
  color. 
  To 
  the 
  

   liquid 
  were 
  added 
  1 
  grm. 
  of 
  tartaric 
  acid, 
  to 
  keep 
  the 
  antimony 
  

   in 
  solution 
  during 
  subsequent 
  treatment, 
  sodium 
  hydrate 
  

   nearly 
  to 
  neutrality, 
  and 
  hydrogen 
  sodium 
  carbonate 
  in 
  excess 
  

   amounting 
  to 
  about 
  20 
  cm. 
  3 
  of 
  the 
  saturated 
  solution 
  ; 
  and 
  the 
  

   antimonious 
  oxide 
  in 
  solution 
  was 
  titrated 
  by 
  decinormal 
  iodine 
  

   standardized 
  against 
  tartar 
  emetic. 
  The 
  details 
  of 
  these 
  exper- 
  

   iments 
  are 
  given 
  in 
  Table 
  I. 
  

  

  In 
  Table 
  II 
  are 
  comprised 
  the 
  accounts 
  of 
  experiments 
  

   similar 
  in 
  general 
  to 
  those 
  of 
  Table 
  I, 
  excepting 
  that 
  the 
  final 
  

  

  