﻿PRODUCTS 
  OF 
  DECOMPOSITION 
  OF 
  COMENIC 
  ACID. 
  229 
  

  

  f 
  6-475 
  grains 
  dried 
  at 
  250° 
  gave 
  

   \ 
  2-520 
  ... 
  sulphate 
  of 
  lime. 
  

  

  

  Experiment. 
  

  

  40-83 
  

  

  

  Calculation. 
  

  

  

  Carbon, 
  

  

  41-14 
  

  

  C 
  12 
  

  

  72 
  

  

  Hydrogen, 
  

  

  1-94 
  

  

  1-71 
  

  

  H 
  3 
  

  

  3 
  

  

  Oxygen, 
  . 
  

  

  . 
  

  

  41-15 
  

  

  o 
  9 
  

  

  72 
  

  

  Lime, 
  

  

  16-02 
  

  

  16-00 
  

  

  CaO 
  

  

  28 
  

  

  100-00 
  100-00 
  175 
  

  

  Hence 
  the 
  composition 
  of 
  the 
  salt 
  dried 
  at 
  250° 
  is 
  represented 
  by 
  the 
  formula 
  

  

  CaO 
  HO, 
  C 
  12 
  H 
  2 
  8 
  . 
  

   The 
  crystals 
  contain 
  seven 
  equivalents 
  water 
  of 
  crystallization. 
  

  

  f 
  7-177 
  grains 
  air-dry 
  salt 
  lost 
  at 
  250° 
  Fahr. 
  

   { 
  1-893 
  ... 
  water. 
  

  

  f 
  8-757 
  grains 
  air-dry 
  salt 
  lost 
  at 
  250° 
  Fahr. 
  

   ( 
  2-270 
  ... 
  water. 
  

  

  these 
  numbers, 
  when 
  calculated 
  for 
  per-centage, 
  give 
  

  

  I. 
  II. 
  Mean. 
  

  

  26-37 
  25-92 
  26-15 
  

  

  and 
  26 
  47 
  is 
  that 
  corresponding 
  to 
  the 
  formula 
  

  

  CaO, 
  HO, 
  C 
  12 
  H 
  2 
  8 
  + 
  7aq. 
  

  

  Neutral 
  Comenate 
  of 
  Lime. 
  — 
  This 
  salt 
  is 
  obtained 
  in 
  the 
  form 
  of 
  crystalline 
  

   grains, 
  when 
  a 
  solution 
  of 
  the 
  acid 
  ammonia 
  salt, 
  to 
  which 
  an 
  excess 
  of 
  ammonia 
  

   has 
  been 
  added, 
  is 
  poured 
  into 
  a 
  solution 
  of 
  chloride 
  of 
  calcium. 
  According 
  to 
  

   the 
  state 
  of 
  dilution 
  of 
  the 
  fluids 
  employed, 
  salts 
  containing 
  different 
  amounts 
  of 
  

   water 
  of 
  crystallization 
  are 
  obtained, 
  and 
  the 
  appearance 
  of 
  the 
  product 
  varies 
  

   accordingly. 
  They 
  are 
  all 
  insoluble 
  in 
  water. 
  The 
  well-washed 
  substance 
  gave 
  

   the 
  following 
  results 
  ; 
  the 
  lime 
  being 
  estimated 
  as 
  sulphate, 
  because 
  the 
  salt 
  

   when 
  dried 
  blows 
  up 
  in 
  a 
  cloud 
  on 
  ignition. 
  

  

  

  / 
  9-670 
  

   { 
  6-270 
  

  

  f 
  6-015 
  

   <^ 
  7-545 
  

   { 
  1-280 
  

  

  grains 
  dried 
  at 
  

   sulphate 
  

  

  grains 
  dried 
  at 
  . 
  

   carbonic 
  

   water. 
  

  

  Experiment. 
  

  

  34-20 
  

   2-36 
  

  

  26-59 
  

  

  250° 
  gave 
  

   of 
  lime. 
  

  

  250° 
  gave 
  

   acid, 
  and 
  

  

  Calculation. 
  

  

  

  Carbon, 
  

   Hydrogen, 
  

   Oxygen, 
  

   Lime, 
  

  

  33-96 
  C 
  12 
  

   1-88 
  H 
  4 
  

   27-75 
  O 
  10 
  

   26-41 
  2 
  CaO 
  

  

  72 
  

  

  4 
  

  

  80 
  

  

  56 
  

  

  100-00 
  100-00 
  212 
  

  

  The 
  formula 
  of 
  the 
  salt, 
  dried 
  at 
  250°, 
  is 
  therefore 
  

  

  2 
  CaO, 
  C 
  12 
  H 
  2 
  O 
  8 
  + 
  2H 
  . 
  

   two 
  equivalents 
  of 
  water 
  being 
  retained 
  at 
  this 
  temperature. 
  

  

  VOL. 
  XX. 
  PART 
  II. 
  3 
  Q 
  

  

  