﻿Chloride 
  upon 
  Analcite 
  and 
  Leucite. 
  119 
  

  

  fourteen 
  days, 
  it 
  lost 
  in 
  weight 
  only 
  0*08 
  per 
  cent. 
  Tested 
  for 
  

   chlorine, 
  only 
  a 
  slight 
  trace 
  could 
  be 
  recognized, 
  but 
  upon 
  

   boiling 
  for 
  fifteen 
  minutes 
  with 
  sodium 
  carbonate 
  solution 
  it 
  

   yielded 
  T97 
  of 
  soluble 
  silica. 
  After 
  ignition 
  only 
  1*70 
  of 
  

   silica 
  was 
  soluble, 
  or 
  somewhat 
  less 
  than 
  before. 
  Upon 
  heat- 
  

   ing 
  to 
  constant 
  weight 
  at 
  300°, 
  only 
  046 
  per 
  cent 
  was 
  lost 
  ; 
  

   but 
  at 
  350° 
  it 
  slowly 
  decomposed, 
  giving 
  off 
  ammonia. 
  At 
  

   300° 
  the 
  compound 
  is 
  stable. 
  

  

  The 
  0-28 
  per 
  cent 
  of 
  soda 
  remaining 
  in 
  residue 
  C 
  may 
  be 
  

   regarded 
  as 
  representing 
  unaltered 
  analcite 
  ; 
  doubtless 
  coarser 
  

   particles 
  which 
  escaped 
  complete 
  transformation. 
  It 
  corre- 
  

   sponds 
  to 
  1*98 
  per 
  cent 
  of 
  analcite 
  ; 
  which, 
  together 
  with 
  the 
  

   1*97 
  of 
  soluble 
  silica, 
  and 
  the 
  046 
  of 
  water 
  lost 
  below 
  300°, 
  

   may 
  be 
  deducted 
  from 
  the 
  substance 
  in 
  order 
  to 
  obtain 
  the 
  

   composition 
  of 
  the 
  definite 
  compound. 
  The 
  latter 
  amounts 
  to 
  

   94-72 
  per 
  cent 
  of 
  the 
  total 
  residue, 
  and 
  agrees 
  very 
  nearly 
  in 
  

   composition 
  with 
  the 
  formula 
  

  

  2NH 
  3 
  .H 
  2 
  O.Al 
  2 
  3 
  .4Si0 
  2 
  . 
  

  

  Recalculating 
  the 
  94*72 
  of 
  residue 
  to 
  100 
  per 
  cent, 
  we 
  get 
  the 
  

   following 
  comparison 
  between 
  analysis 
  and 
  theory. 
  

  

  SiO„__ 
  

  

  A1A 
  

  

  NH, 
  

  

  Found, 
  

  

  61-07 
  

  

  26-15 
  

  

  8-14 
  

  

  Calculated. 
  

  

  60-92 
  

  

  25-88 
  

  

  8-63 
  

  

  H 
  O 
  

  

  4-64 
  

  

  4-57 
  

  

  9 
  

  

  

  

  100-00 
  100-00 
  

  

  Written 
  in 
  rational 
  form 
  the 
  compound 
  becomes 
  equivalent 
  

   to 
  an 
  anhydrous 
  ammonium 
  analcite, 
  

  

  NH 
  4 
  AlSi,0.5 
  

  

  that 
  is, 
  analcite 
  in 
  which 
  sodium 
  has 
  been 
  replaced 
  by 
  ammo- 
  

   nium. 
  From 
  this 
  point 
  of 
  view 
  the 
  reaction 
  between 
  analcite 
  

   and 
  ammonium 
  chloride 
  becomes 
  a 
  simple 
  case 
  of 
  double 
  

   decomposition, 
  and 
  is 
  perfectly 
  intelligible. 
  To 
  establish 
  this 
  

   conclusion, 
  however, 
  corroborative 
  experiments 
  were 
  necessary. 
  

  

  In 
  the 
  first 
  place, 
  the 
  observed 
  equivalency 
  between 
  the 
  

   sodium 
  lost 
  and 
  the 
  ammonia 
  gained 
  might 
  be 
  due 
  to 
  a 
  mere 
  

   coincidence, 
  and 
  so 
  far 
  be 
  illusory. 
  One 
  atom 
  of 
  sodium, 
  tak- 
  

   ing 
  chlorine 
  from 
  ammonium 
  chloride, 
  liberates 
  one 
  molecule 
  

   of 
  ammonia, 
  the 
  amount 
  which 
  the 
  analcite 
  residue 
  has 
  retained. 
  

   Suppose 
  more 
  ammonia 
  were 
  present, 
  — 
  could 
  it 
  be 
  absorbed 
  ? 
  

  

  To 
  answer 
  this 
  question 
  another 
  tube 
  was 
  prepared, 
  with 
  the 
  

   usual 
  mixture 
  of 
  analcite 
  and 
  ammonium 
  chloride. 
  This 
  was 
  

   covered 
  by 
  a 
  loose 
  plug 
  of 
  glass 
  wool, 
  in 
  front 
  of 
  which 
  we 
  

   placed 
  enough 
  pure 
  lime 
  to 
  liberate 
  about 
  double 
  the 
  normal 
  

  

  