﻿368 
  dr 
  Anderson's 
  researches 
  on 
  some 
  of 
  the 
  

  

  Acid 
  Hemipinate 
  of 
  Potass. 
  — 
  This 
  salt 
  was 
  met 
  with 
  at 
  first 
  accidentally 
  in 
  

   an 
  experiment 
  in 
  which, 
  during 
  the 
  preparation 
  of 
  the 
  acid, 
  a 
  sufficient 
  quantity 
  

   of 
  hydrochloric 
  acid 
  was 
  not 
  added 
  to 
  the 
  original 
  alkaline 
  solution 
  ; 
  but 
  it 
  may 
  

   be 
  readily 
  prepared 
  by 
  dividing 
  a 
  quantity 
  of 
  hemipinic 
  acid 
  into 
  two 
  equal 
  quan- 
  

   tities, 
  neutralising 
  one 
  half 
  with 
  potash, 
  then 
  adding 
  the 
  other 
  and 
  evaporating. 
  

   It 
  is 
  deposited 
  in 
  thick 
  six-sided 
  tables 
  sometimes 
  of 
  considerable 
  size. 
  It 
  is 
  

   readily 
  soluble 
  both 
  in 
  cold 
  and 
  hot 
  water 
  and 
  in 
  alcohol, 
  but 
  not 
  in 
  ether, 
  which 
  

   throws 
  it 
  down 
  from 
  its 
  alcoholic 
  solution 
  in 
  shining 
  plates. 
  It 
  is 
  highly 
  acid 
  

   to 
  test 
  paper. 
  Dried 
  at 
  212° 
  it 
  gave 
  the 
  following 
  results 
  : 
  

  

  {6-203 
  grains 
  acid 
  hemipinate 
  of 
  potass 
  gave 
  

   10-245 
  ... 
  carbonic 
  acid, 
  and 
  

   1-935 
  ... 
  water. 
  

  

  5-330 
  grains 
  acid 
  hemipinate 
  of 
  potass 
  gave 
  

   1763 
  ... 
  sulphate 
  of 
  potass. 
  

  

  Carbon, 
  

   Hydrogen, 
  

   Oxygen, 
  

   Potass, 
  

  

  Experiment. 
  

  

  Calculation. 
  

  

  

  45-04 
  

  

  45-42 
  C 
  20 
  

  

  120 
  

  

  3-46 
  

  

  3-40 
  H 
  9 
  

  

  9 
  

  

  

  33-32 
  O 
  u 
  

  

  88 
  

  

  17-88 
  

  

  1786 
  KO 
  

  

  47-2 
  

  

  100-00 
  

  

  13-505 
  grains 
  of 
  the 
  crystallised 
  salt 
  lost, 
  at 
  212°, 
  1950 
  grains 
  =14-43 
  per 
  cent., 
  

   and 
  corresponding 
  to 
  5 
  equivalents 
  of 
  water, 
  the 
  calculated 
  result 
  for 
  which 
  is 
  

   14-55 
  per 
  cent. 
  The 
  formula 
  of 
  the 
  crystallised 
  salt 
  is 
  consequently, 
  

  

  KO 
  HO 
  C 
  20 
  H 
  8 
  O 
  10 
  + 
  5 
  HO. 
  

  

  Neutral 
  Hemipinate 
  of 
  Potass 
  is 
  a 
  highly 
  soluble 
  salt, 
  and 
  crystallises 
  only 
  

   with 
  difficulty. 
  

  

  Neutral 
  Hemipinate 
  of 
  Silver 
  is 
  obtained 
  as 
  a 
  white 
  precipitate, 
  insoluble 
  in 
  

   water. 
  Dried 
  at 
  212° 
  and 
  burned, 
  it 
  gave 
  the 
  following 
  results 
  : 
  — 
  

  

  ("6-278 
  grains 
  hemipinate 
  of 
  silver 
  gave 
  

   I 
  3-098 
  ... 
  silver. 
  

  

  Carbon, 
  

  

  Hydrogen, 
  

  

  Oxygen, 
  

  

  Silver, 
  

  

  Experiment. 
  

  

  Calculation. 
  

  

  

  

  27-27 
  

  

  ^20 
  

  

  120 
  

  

  

  1-81 
  

  

  H 
  s 
  

  

  8 
  

  

  

  21-83 
  

  

  12 
  

  

  96 
  

  

  49-34 
  

  

  49-09 
  

  

  Ag 
  2 
  

  

  216 
  

  

  100-00 
  440 
  

  

  Acid 
  Hemipinic 
  Ether 
  — 
  Hemipinovinic 
  Acid. 
  — 
  When 
  hemipinic 
  acid 
  is 
  dis- 
  

   solved 
  in 
  absolute 
  alcohol, 
  and 
  a 
  current 
  of 
  hydrochloric 
  acid 
  gas 
  passed 
  through 
  

   the 
  solution, 
  hemipinovinic 
  acid 
  is 
  formed. 
  It 
  is 
  obtained 
  in 
  the 
  pure 
  state 
  by 
  

  

  