﻿Clarke 
  and 
  Steiger 
  — 
  Action 
  of 
  Ammonium 
  Chloride^ 
  etc. 
  345 
  

  

  Aet. 
  XXXII. 
  — 
  The 
  Action 
  of 
  Ammonium 
  Chloride 
  upon 
  

   JTatrolite, 
  Scolecite, 
  Prehnite 
  and 
  Pectolite 
  / 
  by 
  F. 
  W. 
  

   Claeke 
  and 
  Geoege 
  Steigee. 
  

  

  Ix 
  our 
  last 
  paper 
  upon 
  the 
  ammonium 
  chloride 
  reaction,* 
  

   we 
  showed 
  that 
  analcite 
  and 
  leucite, 
  when 
  heated 
  to 
  350° 
  with 
  

   this 
  reagent 
  in 
  a 
  sealed 
  tube, 
  both 
  yielded 
  the 
  same 
  compound, 
  

   ammonium 
  leucite, 
  NH 
  4 
  AlSi,0 
  6 
  . 
  We 
  also 
  showed 
  that 
  the 
  

   reaction 
  was 
  not 
  limited 
  to 
  these 
  minerals, 
  but 
  that 
  it 
  was 
  fairly 
  

   general 
  in 
  character 
  ; 
  and 
  that 
  with 
  other 
  species 
  analogous 
  

   results 
  could 
  be 
  obtained. 
  We 
  now 
  have 
  data 
  relative 
  to 
  four 
  

   more 
  minerals, 
  and 
  these 
  exhibit 
  a 
  range 
  of 
  variation 
  which 
  

   well 
  illustrates 
  the 
  availability 
  of 
  the 
  method 
  for 
  investigations 
  

   into 
  the 
  chemical 
  constitution 
  of 
  silicates. 
  Three 
  of 
  the 
  

   species 
  now 
  studied 
  have 
  previously 
  been 
  regarded 
  by 
  one 
  of 
  

   us 
  as 
  analogous 
  in 
  structure, 
  provided 
  that 
  all 
  or 
  part 
  of 
  their 
  

   water 
  can 
  be 
  interpreted 
  as 
  constitutional 
  ; 
  and 
  the 
  formulae 
  

   assigned 
  were 
  as 
  follows 
  : 
  

  

  Scolecite 
  Al 
  2 
  (Si0 
  4 
  ) 
  3 
  CaH 
  4 
  . 
  H 
  2 
  

  

  Natrolite 
  A],(Si0 
  4 
  ) 
  1 
  Na„H 
  4 
  

  

  Prehnite. 
  . 
  _ 
  _ 
  Al 
  2 
  "(Si0 
  4 
  ) 
  3 
  Ca 
  2 
  H 
  2 
  

  

  Two 
  of 
  these 
  formulae 
  must 
  now 
  be 
  abandoned, 
  because 
  of 
  the 
  

   experimental 
  evidence 
  which 
  we 
  have 
  obtained. 
  We 
  may 
  first 
  

   study 
  the 
  three 
  species 
  individually. 
  

  

  Natrolite. 
  

  

  In 
  our 
  former 
  paper 
  we 
  reported 
  a 
  crude, 
  preliminary 
  experi- 
  

   ment 
  made 
  upon 
  impure, 
  yellowish 
  natrolite 
  from 
  Aussig 
  in 
  

   Bohemia. 
  After 
  heating 
  with 
  ammonium 
  chloride 
  in 
  a 
  sealed 
  

   tube 
  and 
  subsequent 
  leaching 
  with 
  water, 
  17*56 
  per 
  cent 
  of 
  

   soda 
  was 
  extracted, 
  and 
  in 
  the 
  residue 
  8*29 
  per 
  cent 
  of 
  ammonia 
  

   was 
  found. 
  Xatrolite, 
  therefore, 
  was 
  a 
  suitable 
  mineral 
  for 
  

   further 
  investigation; 
  and 
  our 
  expectations 
  regarding 
  it 
  have 
  

   been 
  fully 
  confirmed. 
  

  

  The 
  material 
  available 
  for 
  our 
  new 
  experiments 
  came 
  from 
  

   the 
  well 
  known 
  locality 
  at 
  Bergen 
  Hill, 
  JSTew 
  Jersey, 
  and 
  con- 
  

   sisted 
  of 
  a 
  mass 
  of 
  slender 
  needles 
  densely 
  matted 
  together. 
  

   Part 
  of 
  the 
  uniform, 
  ground 
  sample 
  was 
  analyzed, 
  with 
  frac- 
  

   tional 
  determinations 
  of 
  the 
  water, 
  and 
  part 
  was 
  used 
  for 
  the 
  

   sealed 
  tube 
  experiments, 
  precisely 
  as 
  in 
  the 
  research 
  upon 
  anal- 
  

   cite 
  and 
  leucite. 
  Three 
  of 
  these 
  experiments 
  were 
  made 
  ; 
  and 
  

   in 
  each 
  case 
  the 
  natrolite 
  was 
  mixed 
  by 
  grinding 
  in 
  an 
  agate 
  

  

  * 
  This 
  Journal, 
  February, 
  1900. 
  

  

  Am. 
  Jour. 
  Sci. 
  — 
  Fourth 
  Series, 
  Yol. 
  IX, 
  No. 
  53. 
  — 
  May, 
  1900. 
  

   24 
  

  

  