﻿Chloride 
  upon 
  Analcite 
  and 
  Leucite. 
  121 
  

  

  alternatives, 
  and 
  assigned 
  to 
  the 
  substance 
  the 
  formula 
  

   H 
  a 
  Na 
  a 
  Al 
  4 
  Si 
  8 
  24 
  .NH 
  s 
  . 
  In 
  this 
  expression 
  we 
  were 
  influenced 
  

   by 
  the 
  researches 
  of 
  Friedel, 
  who 
  had 
  shown 
  that 
  ammonia 
  

   could 
  in 
  part 
  replace 
  the 
  "zeolitic" 
  water 
  of 
  analcite 
  ; 
  but 
  it 
  

   now 
  appears 
  that 
  the 
  phenomenon 
  observed 
  by 
  him 
  is 
  quite 
  

   distinct 
  from 
  that 
  discovered 
  by 
  us, 
  and, 
  indeed, 
  of 
  an 
  entirely 
  

   different 
  order. 
  We 
  may, 
  therefore, 
  in 
  accordance 
  with 
  our 
  

   new 
  data, 
  rearrange 
  the 
  formula 
  ; 
  transforming 
  it 
  to 
  that 
  of 
  an 
  

   ammonium 
  salt, 
  HNa 
  2 
  NH 
  4 
  Al 
  4 
  Si 
  8 
  24 
  , 
  the 
  agreement 
  with 
  the 
  

   analytical 
  figures 
  being 
  approximate 
  only. 
  The 
  results 
  

   obtained 
  are 
  not 
  sharp 
  enough 
  for 
  certainty. 
  

  

  This 
  product 
  we 
  are 
  now 
  inclined 
  to 
  regard 
  as 
  a 
  mixture, 
  

   although 
  it 
  is 
  not 
  strictly 
  intermediate 
  between 
  analcite 
  and 
  its 
  

   final 
  ammonium 
  derivative. 
  Only 
  half 
  of 
  the 
  eliminated 
  

   sodium 
  has 
  been 
  replaced 
  by 
  ammonium, 
  while 
  hydrogen, 
  or 
  

   water, 
  makes 
  up 
  the 
  deficiency. 
  It 
  seems 
  probable 
  that 
  the 
  

   reaction 
  in 
  the 
  sealed 
  tube 
  and 
  that 
  in 
  the 
  open 
  crucible 
  are 
  at 
  

   first 
  essentially 
  the 
  same; 
  but 
  that 
  in 
  the 
  latter 
  case 
  secondary 
  

   reactions 
  follow 
  which 
  cause 
  the 
  variations 
  in 
  the 
  final 
  results. 
  

   In 
  the 
  sealed 
  tube, 
  the 
  element 
  of 
  pressure 
  comes 
  into 
  play, 
  

   and 
  the 
  reaction 
  is 
  complete. 
  In 
  the 
  open 
  crucible, 
  pressure 
  

   is 
  lacking; 
  some 
  ammonia 
  escapes 
  fixation 
  and 
  reacts 
  upon 
  a 
  

   part 
  of 
  the 
  sodium 
  chloride 
  which 
  was 
  at 
  first 
  formed 
  ; 
  hence 
  

   the 
  composition 
  of 
  the 
  leached 
  residue 
  is 
  essentially 
  modified. 
  

   This 
  residue 
  may 
  be 
  a 
  definite 
  compound 
  ; 
  but 
  the 
  case 
  in 
  its 
  

   favor 
  is 
  unproved, 
  and 
  the 
  presumption 
  is 
  rather 
  against 
  it. 
  

  

  Between 
  analcite 
  and 
  leucite 
  the 
  closest 
  analogies 
  have 
  long 
  

   been 
  recognized. 
  The 
  two 
  minerals 
  have 
  similar 
  composition, 
  

   they 
  resemble 
  each 
  other 
  in 
  crystalline 
  form, 
  and 
  they 
  yield, 
  

   upon 
  alteration, 
  products 
  of 
  the 
  same 
  order. 
  Recently 
  also, 
  

   analcite, 
  like 
  leucite, 
  has 
  been 
  identified 
  as 
  a 
  not 
  uncommon 
  

   constituent 
  of 
  volcanic 
  rocks 
  ; 
  analcite-basalt 
  being 
  a 
  good 
  exam- 
  

   ple. 
  In 
  view 
  of 
  these 
  resemblances, 
  it 
  was 
  plainly 
  desirable 
  to 
  

   compare 
  the 
  minerals 
  by 
  means 
  of 
  the 
  ammonium 
  chloride 
  

   reaction 
  ; 
  a 
  task 
  which 
  has 
  been 
  performed 
  with 
  satisfactory 
  

   results. 
  

  

  In 
  a 
  preliminary 
  experiment 
  a 
  sample 
  of 
  leucite, 
  taken 
  with- 
  

   out 
  regard 
  to 
  purity, 
  was 
  heated 
  with 
  ammonium 
  chloride 
  to 
  

   350° 
  in 
  a 
  sealed 
  tube. 
  Potassium 
  chloride 
  was 
  formed 
  corre- 
  

   sponding 
  to 
  18*06 
  percent 
  of 
  potash, 
  and 
  in 
  the 
  leached 
  residue 
  

   6*90 
  per 
  cent 
  of 
  ammonia 
  was 
  found. 
  The 
  foreseen 
  reaction 
  

   had 
  occurred, 
  and 
  more 
  careful 
  work 
  was 
  accordingly 
  under- 
  

   taken. 
  

  

  Our 
  material 
  consisted 
  of 
  a 
  large, 
  irregular 
  crystal 
  of 
  leucite 
  

   from 
  Vesuvius, 
  which 
  yielded 
  about 
  twenty 
  grams 
  of 
  the 
  pure 
  

   mineral. 
  This 
  was 
  ground 
  to 
  a 
  uniform 
  sample, 
  and 
  a 
  portion 
  

   of 
  it 
  was 
  analyzed 
  ; 
  the 
  analysis 
  will 
  be 
  given 
  presently. 
  The 
  

  

  