﻿254: 
  Clarke 
  and 
  Steiger 
  — 
  Experiments 
  with 
  Pectolite, 
  etc. 
  

  

  This 
  represents 
  a 
  quadrupled 
  analcite 
  formula, 
  in 
  whicli 
  half 
  

   of 
  the 
  sodium 
  is 
  replaced 
  by 
  hydrogen, 
  and 
  with 
  NHg 
  in 
  place 
  

   of 
  ^H^O. 
  The 
  analytical 
  comparison 
  is 
  as 
  follows 
  : 
  

  

  SiO, 
  

   AI.O3 
  

   CaO 
  

   Na,0 
  

  

  Found. 
  

  

  Calculated 
  

  

  62-59 
  

  

  61-46 
  

  

  24-34 
  

  

  26-12 
  

  

  •18 
  

  

  

  8-11 
  

  

  '7-94 
  

  

  2-32 
  

  

  2-30 
  

  

  2-46 
  

  

  2-18 
  

  

  10000 
  100-00 
  

  

  The 
  agreement 
  is 
  not 
  close, 
  but 
  it 
  is 
  close 
  enough 
  to 
  be 
  sug- 
  

   gestive, 
  and 
  to 
  indicate 
  the 
  character 
  of 
  the 
  reaction 
  which 
  has 
  

   taken 
  place. 
  It 
  needs, 
  however, 
  verification 
  by 
  additional 
  ex- 
  

   periments 
  upon 
  other 
  preparations, 
  and 
  upon 
  analcite 
  from 
  

   other 
  sources. 
  In 
  this 
  connection 
  it 
  may 
  be 
  well 
  to 
  reiterate 
  

   that 
  the 
  substance 
  was 
  prepared 
  by 
  very 
  long 
  heating 
  at 
  350°, 
  

   and 
  is 
  therefore 
  stable 
  at 
  that 
  temperature. 
  

  

  An 
  interesting 
  feature 
  of 
  these 
  experiments 
  is 
  their 
  harmony 
  

   with 
  the 
  researches 
  of 
  G. 
  Friedel,^ 
  who 
  has 
  shown 
  that 
  the 
  

   water 
  of 
  zeolites 
  may 
  be 
  replaced 
  by 
  ammonia 
  and 
  other 
  sub- 
  

   stances, 
  without 
  change 
  of 
  the 
  crystalline 
  structure. 
  In 
  the 
  

   case 
  of 
  analcite, 
  ammonia 
  was 
  taken 
  up 
  to 
  the 
  extent 
  of 
  2-04: 
  

   per 
  cent 
  ; 
  or 
  almost 
  exactly 
  the 
  amount 
  found 
  in 
  our 
  analcite 
  

   residue. 
  The 
  great 
  difference 
  between 
  Friedel's 
  method 
  of 
  

   experimentation 
  and 
  ours, 
  renders 
  the 
  agreement 
  all 
  the 
  more 
  

   striking; 
  and 
  sustains 
  our 
  belief 
  that 
  the 
  mineral 
  and 
  the 
  

   residue 
  are 
  compounds 
  of 
  the 
  same 
  general 
  order. 
  We 
  hope 
  

   to 
  continue 
  our 
  experiments 
  and 
  to 
  extend 
  our 
  investigation 
  

   to 
  other 
  zeolites. 
  

  

  If, 
  now, 
  analcite 
  and 
  its 
  derivative, 
  our 
  analcite 
  residue, 
  are 
  

   analogous 
  compounds, 
  the 
  relation 
  between 
  them 
  is 
  expressed 
  

   by 
  these 
  formulae 
  : 
  

  

  Analcite 
  Na,Al,Si,0,, 
  . 
  4H,0. 
  

  

  Analcite 
  residue 
  ._ 
  H^Na^Ai^SigO^^ 
  . 
  NH3. 
  

  

  That 
  is, 
  the 
  minimum 
  molecular 
  weight 
  assignable 
  to 
  analcite 
  

   is 
  represented 
  by 
  four 
  times 
  its 
  empirical 
  formula. 
  Other 
  in- 
  

   terpretations 
  of 
  the 
  evidence 
  are 
  possible, 
  but 
  this 
  appears 
  to 
  

   be 
  the 
  simplest. 
  The 
  water 
  of 
  analcite, 
  as 
  Friedel 
  has 
  shown, 
  

   must 
  be 
  regarded 
  as 
  water 
  only, 
  not 
  as 
  hydroxyl 
  ; 
  for 
  it 
  can 
  be 
  

   expelled 
  by 
  heat 
  without 
  destruction 
  of 
  the 
  crystalline 
  nucleus, 
  

   the 
  anhydrous 
  salt, 
  and 
  is 
  taken 
  up 
  again 
  from 
  moist 
  air. 
  

  

  * 
  Bull. 
  Soc. 
  Min., 
  xix, 
  94, 
  1896. 
  

  

  