﻿PRODUCTS 
  OF 
  DECOMPOSITION 
  OF 
  COMENIC 
  ACID. 
  237 
  

  

  The 
  per-centage 
  calculated 
  from 
  these 
  numbers 
  are, 
  

  

  I. 
  II. 
  Mean. 
  

  

  4-22 
  4-66 
  4-44 
  

  

  the 
  mean 
  of 
  which 
  agrees 
  well 
  enough 
  with 
  the 
  number 
  4-33, 
  corresponding 
  to 
  

  

  the 
  formula 
  

  

  2 
  (AgO, 
  HO, 
  C 
  ]2 
  HC1 
  8 
  ) 
  + 
  3 
  aq. 
  

  

  Neutral 
  Chlorocomenate 
  of 
  Silver. 
  — 
  This 
  salt 
  is 
  obtained 
  in 
  the 
  form 
  of 
  a 
  yellow, 
  

   flocky, 
  amorphous 
  substance, 
  on 
  the 
  addition 
  of 
  a 
  solution 
  of 
  the 
  acid 
  in 
  a 
  slight 
  

   excess 
  of 
  ammonia 
  to 
  nitrate 
  of 
  silver. 
  It 
  is 
  insoluble 
  in 
  boiling 
  water, 
  and 
  

   acquires, 
  in 
  the 
  process 
  of 
  drying, 
  the 
  consistence 
  and 
  adhesiveness 
  of 
  clay, 
  which 
  

   it 
  also 
  closely 
  resembles 
  in 
  appearance. 
  

  

  Considerable 
  difficulty 
  was 
  experienced 
  in 
  the 
  analysis 
  of 
  the 
  salt 
  ; 
  since, 
  for 
  

   the 
  reason 
  mentioned 
  with 
  regard 
  to 
  the 
  acid 
  salt, 
  it 
  cannot 
  be 
  burned, 
  and 
  it 
  is, 
  

   moreover, 
  insoluble 
  in 
  water. 
  When 
  boiled 
  with 
  hydrochloric 
  acid, 
  a 
  part 
  of 
  it 
  

   escapes 
  decomposition 
  ; 
  and 
  if 
  the 
  attempt 
  be 
  made 
  to 
  dissolve 
  it 
  by 
  aid 
  of 
  nitric 
  

   acid, 
  and 
  precipitate 
  the 
  silver 
  by 
  hydrochloric 
  acid, 
  care 
  must 
  be 
  taken 
  to 
  prevent 
  

   the 
  formation 
  of 
  cyanide 
  of 
  silver, 
  which 
  readily 
  takes 
  place 
  when 
  either 
  of 
  the 
  

   silver 
  salts 
  is 
  kept 
  warm 
  with 
  even 
  dilute 
  nitric 
  acid. 
  The 
  number 
  I 
  obtained 
  

   was 
  by 
  carefully 
  employing 
  this 
  process, 
  and, 
  though 
  not 
  accurate, 
  comes 
  suffi- 
  

   ciently 
  near 
  to 
  prove 
  the 
  composition 
  of 
  the 
  salt. 
  

  

  f 
  7760 
  grains 
  dried 
  at 
  212° 
  gave 
  

   \ 
  5-457 
  ... 
  chloride 
  of 
  silver. 
  

  

  The 
  per-centage 
  of 
  oxide 
  of 
  silver 
  calculated 
  from 
  this 
  is 
  56*85, 
  and 
  57*37 
  is 
  that 
  

   corresponding 
  to 
  the 
  formula 
  

  

  2AgO,C 
  12 
  (HJo 
  8 
  . 
  

  

  The 
  other 
  salts 
  of 
  chlorocomenic 
  acid, 
  as 
  might 
  be 
  anticipated, 
  present 
  close 
  

   analogies 
  with 
  those 
  of 
  comenic 
  acid 
  ; 
  the 
  former 
  are 
  generally 
  more 
  soluble 
  than 
  

   the 
  latter. 
  I 
  have 
  been 
  unable 
  to 
  prepare 
  neutral 
  salts 
  of 
  the 
  alkalies. 
  

  

  The 
  acid 
  salts 
  of 
  potass, 
  soda, 
  and 
  ammonia, 
  crystallize 
  readily 
  ; 
  a 
  solution 
  of 
  

   the 
  latter 
  salt 
  gives, 
  with 
  chlorides 
  of 
  calcium 
  and 
  barium, 
  radiated 
  groups 
  of 
  

   needles, 
  appearing 
  more 
  or 
  less 
  quickly 
  according 
  to 
  the 
  state 
  of 
  concentration 
  of 
  

   the 
  fluids; 
  with 
  sulphate 
  of 
  magnesia, 
  a 
  few 
  crystals 
  after 
  some 
  time; 
  with 
  

   sulphate 
  of 
  copper, 
  a 
  rapidly-appearing 
  crystalline 
  salt. 
  The 
  neutral 
  salts 
  of 
  these 
  

   bases 
  appear 
  to 
  be 
  insoluble 
  amorphous 
  substances 
  generally. 
  

  

  Action 
  of 
  Bromine 
  on 
  Comenic 
  Acid. 
  

  

  Bromocomenic 
  Acid. 
  — 
  As 
  might 
  be 
  expected, 
  the 
  behaviour 
  of 
  comenic 
  acid 
  

  

  towards 
  bromine 
  is 
  closely 
  similar 
  to 
  that 
  which 
  it 
  exhibits 
  when 
  submitted 
  to 
  

  

  the 
  influence 
  of 
  chlorine. 
  It 
  dissolves 
  readily 
  in 
  aqueous 
  bromine, 
  yielding 
  a 
  

  

  colourless 
  fluid 
  if 
  the 
  bromine 
  is 
  not 
  in 
  great 
  excess. 
  In 
  the 
  course 
  of 
  a 
  few 
  hours 
  

  

  vol. 
  xx. 
  PART 
  II. 
  3 
  s 
  

  

  