﻿4:46 
  Kr 
  eider 
  — 
  Preparation 
  of 
  Perchloric 
  Acid 
  and 
  its 
  

  

  nearly 
  all 
  removed, 
  when 
  more 
  of 
  the 
  chloride 
  seems 
  to 
  dissolve. 
  

   This 
  treatment 
  with 
  alcohol 
  is 
  continued 
  until, 
  on 
  evaporation 
  

   of 
  a 
  small 
  portion 
  of 
  the 
  latest 
  filtrate, 
  only 
  a 
  small 
  residue 
  is 
  

   found. 
  The 
  alcoholic 
  solution 
  of 
  the 
  perchlorate 
  is 
  then 
  dis- 
  

   tilled 
  from 
  a 
  large 
  flask 
  until 
  the 
  perchlorate 
  begins 
  to 
  crystal- 
  

   lize, 
  when 
  the 
  heat 
  is 
  removed 
  and 
  the 
  contents 
  quickly 
  

   emptied 
  into 
  an 
  evaporating 
  dish, 
  the 
  same 
  liquid 
  being 
  used 
  

   to 
  wash 
  out 
  the 
  remaining 
  portions 
  of 
  the 
  salt. 
  When 
  the 
  dis- 
  

   tillation 
  is 
  terminated 
  at 
  the 
  point 
  indicated, 
  the 
  distillate 
  will 
  

   contain 
  most 
  of 
  the 
  alcohol 
  employed, 
  but 
  in 
  a 
  somewhat 
  

   stronger 
  solution, 
  so 
  that 
  it 
  requires 
  only 
  diluting 
  to 
  97 
  per 
  

   cent 
  to 
  fit 
  it 
  for 
  use 
  in 
  future 
  preparations. 
  The 
  salt 
  is 
  then 
  

   evaporated 
  to 
  dryness 
  on 
  the 
  steam 
  bath 
  and 
  subsequently 
  

   treated 
  with 
  strong 
  hydrochloric 
  acid 
  for 
  the 
  separation 
  of 
  the 
  

   perchloric 
  acid. 
  

  

  One 
  cubic 
  centimeter 
  of 
  the 
  acid 
  prepared 
  in 
  this 
  way, 
  on 
  

   evaporation 
  gave 
  a 
  residue 
  in 
  one 
  case 
  of 
  0-0369 
  grms., 
  and 
  in 
  

   another 
  0*0307 
  grm., 
  completely 
  soluble 
  in 
  97 
  per 
  cent 
  alcohol, 
  

   which 
  was 
  then 
  ignited 
  and 
  the 
  chlorine 
  determined 
  by 
  silver 
  

   from 
  which 
  the 
  equivalent 
  of 
  perchloric 
  acid 
  in 
  the 
  form 
  of 
  

   salts 
  was 
  calculated 
  as 
  0*0305 
  grm. 
  By 
  neutralizing 
  the 
  acid 
  

   with 
  sodium 
  carbonate, 
  evaporating, 
  igniting 
  in 
  an 
  atmosphere 
  

   of 
  carbon 
  dioxide 
  till 
  decomposition 
  was 
  complete, 
  collecting 
  

   the 
  oxygen 
  over 
  caustic 
  potash, 
  allowing 
  it 
  to 
  act 
  on 
  hydriodic 
  

   acid 
  by 
  intervention 
  of 
  nitric 
  oxide, 
  according 
  to 
  a 
  process 
  

   soon 
  to 
  be 
  published, 
  titrating 
  the 
  iodin 
  liberated, 
  with 
  stand- 
  

   ard 
  arsenic 
  and 
  calculating 
  the 
  equivalent 
  of 
  perchloric 
  acid, 
  

   after 
  subtracting 
  the 
  amount 
  of 
  acid 
  found 
  in 
  the 
  form 
  of 
  salts, 
  

   the 
  amount 
  of 
  free 
  acid 
  per 
  cubic 
  centimeter 
  proved 
  to 
  be 
  

   0*9831 
  grms. 
  

  

  The 
  whole 
  process, 
  even 
  when 
  the 
  separation 
  with 
  alcohol 
  is 
  

   necessary, 
  can 
  not 
  well 
  require 
  more 
  than 
  two 
  days 
  and 
  during 
  

   the 
  greater 
  part 
  of 
  that 
  time 
  the 
  work 
  proceeds 
  without 
  atten- 
  

   tion. 
  

  

  In 
  applying 
  perchloric 
  acid, 
  thus 
  prepared, 
  to 
  the 
  determina- 
  

   tion 
  of 
  potassium 
  according 
  to 
  the 
  treatment 
  suggested 
  by 
  

   Caspari* 
  very 
  satisfactory 
  results 
  were 
  obtained. 
  Briefly, 
  the 
  

   method 
  is 
  as 
  follows 
  : 
  The 
  substance, 
  free 
  from 
  sulphuric 
  acid, 
  

   is 
  evaporated 
  to 
  the 
  expulsion 
  of 
  free 
  hydrochloric 
  acid, 
  the 
  

   residue 
  stirred 
  with 
  20 
  cm 
  3 
  of 
  hot 
  water 
  and 
  then 
  treated 
  with 
  

   perchloric 
  acid 
  in 
  quantity 
  not 
  less 
  than 
  one 
  and 
  one-half 
  times 
  

   that 
  required 
  by 
  the 
  bases 
  present, 
  when 
  it 
  is 
  evaporated 
  with 
  

   frequent 
  stirring 
  to 
  a 
  thick, 
  syrup-like 
  consistency, 
  again 
  dis- 
  

   solved 
  in 
  hot 
  water 
  and 
  evaporated 
  with 
  continued 
  stirring 
  till 
  

   all 
  hydrochloric 
  acid 
  has 
  been 
  expelled 
  and 
  the 
  fumes 
  of 
  per- 
  

  

  * 
  loc. 
  cit. 
  

  

  