﻿120 
  Clarke 
  and 
  Steiger 
  — 
  Action 
  of 
  Ammonium 
  

  

  amount 
  of 
  ammonia. 
  The 
  tube 
  was 
  then 
  sealed, 
  and 
  heated 
  to 
  

   350° 
  as 
  in 
  the 
  previous 
  experiments. 
  Upon 
  opening 
  the 
  tube, 
  

   a 
  strong 
  outrush 
  of 
  ammonia 
  was 
  noticed 
  ; 
  but 
  in 
  the 
  leached 
  

   and 
  thoroughly 
  washed 
  residue 
  only 
  7*52 
  per 
  cent 
  of 
  ammonia 
  

   was 
  found. 
  This 
  quantity 
  agrees 
  with 
  that 
  from 
  the 
  previous 
  

   samples, 
  and 
  shows 
  that 
  the 
  limit 
  of 
  the 
  reaction 
  has 
  been 
  

   practically 
  reached. 
  One 
  molecule 
  of 
  ammonia 
  is 
  retained, 
  

   and 
  no 
  more. 
  

  

  Still 
  another 
  experiment 
  was 
  tried 
  upon 
  a 
  portion 
  of 
  the 
  

   residue 
  marked 
  C. 
  If 
  the 
  compound 
  is 
  really 
  an 
  ammonium 
  

   salt, 
  it 
  should 
  be 
  decomposable 
  by 
  caustic 
  soda 
  in 
  such 
  a 
  way 
  

   as 
  to 
  reverse 
  the 
  reaction 
  by 
  which 
  it 
  had 
  been 
  obtained. 
  The 
  

   substance, 
  however, 
  is 
  very 
  insoluble, 
  so 
  that 
  the 
  reaction 
  takes 
  

   place 
  slowly. 
  To 
  phenol 
  phthalein 
  it 
  is 
  absolutely 
  neutral, 
  and 
  

   with 
  Nessler's 
  reagent 
  it 
  reacts 
  only 
  after 
  long 
  standing. 
  

  

  To 
  settle 
  the 
  question 
  a 
  weighed 
  portion 
  of 
  the 
  compound 
  

   was 
  boiled 
  in 
  a 
  distilling 
  flask 
  with 
  a 
  ten 
  per 
  cent 
  solution 
  of 
  

   sodium 
  hydroxide, 
  to 
  which 
  water 
  was 
  added 
  from 
  time 
  to 
  

   time. 
  The 
  distillate 
  was 
  collected 
  in 
  a 
  tube 
  containing 
  aqueous 
  

   hydrochloric 
  acid 
  ; 
  and 
  the 
  ammonia 
  which 
  passed 
  over 
  was 
  

   weighed, 
  ultimately 
  as 
  chloroplatinate. 
  By 
  four 
  hours 
  boiling 
  

   6'90 
  per 
  cent 
  of 
  ammonia 
  was 
  driven 
  off 
  and 
  determined 
  ; 
  and 
  

   the 
  residue 
  remaining 
  in 
  the 
  flask, 
  after 
  washing 
  until 
  no 
  alka- 
  

   line 
  reaction 
  could 
  be 
  detected 
  in 
  the 
  wash-water, 
  was 
  examined 
  

   for 
  soda, 
  of 
  which 
  10*41 
  per 
  cent 
  was 
  found. 
  The 
  anticipated 
  

   reaction 
  had 
  taken 
  place, 
  although 
  not 
  completely 
  ; 
  it 
  was 
  

   enough, 
  however, 
  to 
  confirm 
  our 
  opinion, 
  and 
  to 
  establish 
  the 
  

   nature 
  of 
  the 
  new 
  compound 
  beyond 
  reasonable 
  doubt. 
  Other 
  

   confirmation 
  was 
  obtained 
  later, 
  from 
  the 
  study 
  of 
  leucite. 
  

  

  The 
  foregoing 
  paragraphs 
  now 
  enable 
  us 
  to 
  understand 
  a 
  phe- 
  

   nomenon 
  which 
  we 
  observed 
  in 
  our 
  work 
  with 
  the 
  open 
  crucible. 
  

   In 
  that 
  case 
  a 
  partial 
  reaction 
  takes 
  place 
  between 
  the 
  analcite 
  

   and 
  the 
  ammonium 
  chloride, 
  producing, 
  as 
  in 
  the 
  sealed 
  tube, 
  

   a 
  mixture 
  of 
  an 
  ammonium 
  alumino 
  silicate 
  with 
  sodium 
  

   chloride 
  ; 
  the 
  two 
  substances 
  being 
  separable 
  by 
  leaching. 
  

   But 
  if, 
  instead 
  of 
  leaching, 
  the 
  mixture 
  be 
  heated 
  to 
  full 
  red- 
  

   ness, 
  ammonium 
  chloride 
  is 
  reformed 
  and 
  given 
  off, 
  leaving 
  a 
  

   residue 
  which 
  contains 
  little 
  or 
  no 
  sodium 
  chloride, 
  and 
  is 
  

   wholly 
  insoluble, 
  or 
  almost 
  so, 
  in 
  water. 
  That 
  is, 
  the 
  reaction 
  

   which 
  occurs 
  at 
  350° 
  is 
  reversed 
  at 
  the 
  higher 
  temperature, 
  and 
  

   anhydrous 
  analcite, 
  or 
  an 
  isomer 
  of 
  it, 
  is 
  regenerated. 
  Ammo- 
  

   nium 
  and 
  sodium 
  again 
  change 
  places, 
  and 
  the 
  original 
  state 
  of 
  

   molecular 
  equilibrium 
  is 
  restored. 
  

  

  What, 
  now, 
  is 
  the 
  nature 
  of 
  the 
  product 
  obtained 
  in 
  the 
  

   open 
  crucible, 
  after 
  sodium 
  chloride 
  has 
  been 
  removed? 
  Is 
  it 
  

   a 
  definite, 
  intermediate 
  compound, 
  or 
  an 
  indeterminate 
  mix- 
  

   ture 
  ? 
  In 
  our 
  former 
  paper 
  we 
  adopted 
  the 
  first 
  of 
  these 
  

  

  