﻿228 
  MR 
  HENRY 
  HOW 
  ON 
  CERTAIN 
  SALTS 
  AND 
  

  

  Bicomenate 
  of 
  Soda. 
  

  

  Comenic 
  acid 
  was 
  dissolved 
  in 
  a 
  tolerably 
  strong 
  solution 
  of 
  caustic 
  soda 
  by 
  

   boiling 
  ; 
  the 
  fluid 
  on 
  cooling 
  deposited 
  two 
  forms 
  of 
  crystals, 
  one 
  in 
  mammillated 
  

   masses, 
  the 
  other 
  in 
  transparent 
  prisms 
  half 
  an 
  inch 
  in 
  length. 
  On 
  washing 
  the 
  

   mixture 
  with 
  a 
  little 
  cold, 
  and 
  resolution 
  in 
  boiling, 
  water, 
  no 
  deposit 
  was 
  obtained 
  

   on 
  cooling, 
  even 
  after 
  the 
  lapse 
  of 
  some 
  hours 
  ; 
  but 
  on 
  evaporation 
  of 
  the 
  fluid 
  to 
  

   about 
  two-thirds 
  of 
  its 
  bulk, 
  groups 
  of 
  mammillary 
  crystals 
  appeared, 
  which 
  when 
  

   magnified 
  were 
  found 
  to 
  consist 
  of 
  four-sided 
  elongated 
  prisms. 
  From 
  this 
  it 
  

   appears 
  that 
  the 
  salt 
  is 
  much 
  more 
  soluble 
  than 
  either 
  the 
  potass 
  and 
  ammonia 
  

   salt, 
  and 
  cannot 
  be 
  employed 
  with 
  advantage 
  in 
  the 
  preparation 
  of 
  comenic 
  acid. 
  

   It 
  has 
  an 
  acid 
  reaction, 
  and 
  is 
  anhydrous; 
  its 
  analysis 
  is 
  subjoined. 
  The 
  soda 
  

   was 
  determined 
  by 
  simple 
  ignition, 
  and 
  subsequent 
  weighing 
  of 
  the 
  carbonate 
  of 
  

   soda 
  produced 
  

  

  f 
  6-020 
  grains 
  dried 
  at 
  212° 
  gave 
  

   \ 
  1-753 
  ... 
  carbonate 
  of 
  soda. 
  

  

  The 
  per-centage 
  of 
  soda 
  calculated 
  from 
  this 
  experiment 
  is 
  1709 
  : 
  17*41, 
  being 
  

   that 
  corresponding 
  with 
  the 
  formula 
  

  

  NaO, 
  HO, 
  C 
  12 
  H, 
  8 
  . 
  

  

  It 
  is 
  obvious, 
  from 
  the 
  foregoing 
  experiments, 
  that 
  neutral 
  salts 
  of 
  comenic 
  

  

  acid 
  with 
  the 
  fixed 
  alkalies 
  or 
  with 
  ammonia 
  do 
  not 
  exist 
  in 
  the 
  dry 
  state. 
  That 
  

  

  this 
  is 
  not 
  the 
  case 
  with 
  reference 
  to 
  the 
  alkaline 
  earths, 
  I 
  shall 
  now 
  proceed 
  to 
  

  

  shew. 
  

  

  Salts 
  of 
  Lime 
  with 
  Comenic 
  Acid. 
  

  

  Finely-powdered 
  comenic 
  acid, 
  mixed 
  with 
  water 
  and 
  an 
  excess 
  of 
  carbonate 
  

   of 
  lime, 
  decomposes 
  the 
  earthy 
  salt 
  with 
  effervescence, 
  in 
  the 
  cold. 
  When 
  the 
  

   liquid 
  is 
  boiled 
  for 
  some 
  time, 
  then 
  filtered 
  and 
  allowed 
  to 
  stand, 
  a 
  few 
  rhombic 
  

   crystals 
  appear 
  ; 
  but 
  by 
  far 
  the 
  larger 
  proportion 
  of 
  the 
  acid 
  remains 
  on 
  the 
  filter 
  

   in 
  combination 
  with 
  the 
  lime, 
  mixed 
  with 
  the 
  excess 
  of 
  carbonate 
  employed. 
  The 
  

   crystals 
  were 
  in 
  very 
  small 
  quantity 
  ; 
  they 
  consisted 
  doubtless 
  of 
  the 
  acid 
  salt, 
  

   which 
  I 
  obtained 
  more 
  conveniently 
  in 
  another 
  way. 
  

  

  Bicomenate 
  of 
  Lime. 
  — 
  When 
  a 
  cold, 
  saturated, 
  aqueous 
  solution 
  of 
  bicomenate 
  

   of 
  ammonia 
  is 
  added 
  to 
  a 
  solution 
  of 
  chloride 
  of 
  calcium, 
  brilliant 
  crystals 
  soon 
  

   begin 
  to 
  appear 
  which 
  gradually 
  increase 
  in 
  quantity. 
  They 
  are, 
  though 
  small, 
  

   perfectly 
  defined 
  transparent 
  rhombs 
  ; 
  they 
  dissolve 
  readily 
  in 
  boiling 
  water, 
  and 
  

   are 
  deposited 
  on 
  cooling 
  of 
  a 
  larger 
  size 
  than 
  when 
  first 
  obtained. 
  In 
  the 
  follow- 
  

   ing 
  analysis 
  the 
  substance 
  was 
  dried 
  at 
  250° 
  Fahr., 
  as 
  it 
  was 
  found 
  that 
  the 
  whole 
  

   water 
  of 
  crystallization 
  was 
  not 
  expelled 
  at 
  212°, 
  or 
  only 
  after 
  the 
  lapse 
  of 
  a 
  very 
  

   long 
  time. 
  The 
  lime 
  was 
  determined 
  as 
  sulphate, 
  by 
  ignition 
  with 
  a 
  few 
  drops 
  of 
  

   sulphuric 
  acid, 
  as 
  the 
  salt 
  swelled 
  up 
  inconveniently 
  when 
  heated 
  by 
  itself. 
  

  

  {4-512 
  grains 
  dried 
  at 
  250° 
  Fahr. 
  gave 
  

   6755 
  ... 
  carbonic 
  acid, 
  and 
  

   0-788 
  ... 
  water. 
  

  

  

  