﻿448 
  D. 
  A. 
  Kr 
  eider 
  — 
  Preparation 
  of 
  Perchloric 
  Acid, 
  etc. 
  

  

  acid 
  solution, 
  some 
  potassium 
  is 
  carried 
  down 
  with 
  the 
  

   barium. 
  Phosphoric 
  acid 
  need 
  not 
  be 
  previously 
  removed 
  ; 
  

   but 
  to 
  secure 
  a 
  nearly 
  complete 
  separation 
  of 
  this 
  acid 
  from 
  

   the 
  potassium, 
  a 
  considerable 
  excess 
  of 
  perchloric 
  acid 
  should 
  

   be 
  left 
  upon 
  the 
  potassium 
  perchlorate 
  before 
  it 
  is 
  treated 
  with 
  

   the 
  alcohol. 
  When 
  these 
  conditions 
  are 
  carefully 
  complied 
  

   with, 
  fairly 
  good 
  results 
  may 
  justly 
  be 
  expected. 
  Below 
  are 
  

   given 
  a 
  number 
  of 
  the 
  results 
  obtained. 
  

  

  Compounds 
  taken, 
  

   grms. 
  

  

  KOI 
  = 
  0-1000 
  ^ 
  

  

  CaC0 
  3 
  = 
  0-13 
  

  

  MgS0 
  4 
  = 
  0-13 
  

  

  Fe 
  2 
  Cl 
  6 
  = 
  005 
  

  

  A1 
  2 
  (S0 
  4 
  ) 
  3 
  = 
  0-05 
  

  

  Mn0 
  2 
  = 
  0-05 
  

  

  HNa 
  9 
  P(V12H 
  a 
  O 
  = 
  0-40 
  

  

  Yol. 
  of 
  KC10 
  4 
  Error 
  on 
  Error 
  on 
  Error 
  on 
  

  

  filtrate. 
  

   cm 
  3 
  . 
  

  

  50 
  

   82 
  

   80 
  

   80 
  

   92 
  

   60 
  

  

  found, 
  

   grms. 
  

  

  0-188*7 
  

   0-1875 
  

   0-1861 
  

   0-1843 
  

   0-1839 
  

   0-1854 
  

  

  KCIO, 
  

   grms. 
  

  

  00028 
  + 
  

   0-0016 
  + 
  

   0-0002 
  + 
  

   0-0016- 
  

   0-0020- 
  

   0-0005- 
  

  

  KC1. 
  

  

  grms. 
  

  

  0-0014 
  + 
  

   0-0008 
  + 
  

   0-0001 
  + 
  

   0-0008- 
  

   0-0010- 
  

   0-0002- 
  

  

  K 
  2 
  0. 
  

  

  grms. 
  

  

  0-0009 
  + 
  * 
  

   0-0005 
  + 
  * 
  

   0-0001 
  + 
  + 
  

   0-0005-f 
  

   0-0006— 
  |- 
  

   0-0002— 
  I 
  

  

  In 
  the 
  last 
  three 
  experiments 
  of 
  the 
  above 
  table 
  the 
  amount 
  

   of 
  perchloric 
  acid 
  was 
  about 
  three 
  times 
  that 
  required 
  to 
  unite 
  

   with 
  the 
  bases 
  present 
  and 
  the 
  phosphoric 
  acid 
  subsequently 
  

   found 
  with 
  the 
  potassium 
  was 
  hardly 
  enough 
  to 
  appreciably 
  

   affect 
  the 
  weight, 
  although 
  its 
  absolute 
  removal 
  was 
  found 
  

   impossible. 
  

  

  The 
  kindly 
  direction 
  and 
  frequent 
  advice 
  of 
  Professor 
  F. 
  A. 
  

   Gooch, 
  during 
  the 
  investigation, 
  is 
  gratefully 
  acknowledged. 
  

  

  * 
  The 
  residue 
  showed 
  phosphoric 
  acid 
  plainly 
  when 
  tested, 
  

   f 
  Only 
  traces 
  of 
  phosphoric 
  acid 
  found 
  in 
  the 
  residue. 
  

  

  