﻿ujpo?i 
  Natrolite, 
  Seolecite, 
  Prehnite 
  and 
  Pectolite. 
  347 
  

  

  Two 
  other 
  experiments 
  upon 
  natrolite 
  remain 
  to 
  be 
  noticed. 
  

   First, 
  the 
  fresh 
  mineral 
  was 
  boiled 
  for 
  15 
  minutes 
  with 
  a 
  25 
  per 
  

   cent 
  sodium 
  carbonate 
  solution 
  ; 
  0*72 
  per 
  cent 
  of 
  silica 
  dissolved. 
  

   Similar 
  treatment 
  of 
  ignited 
  natrolite 
  took 
  out 
  0*62 
  per 
  cent. 
  

   No 
  silica 
  is 
  split 
  off 
  by 
  ignition. 
  Ammonia 
  m-natrolite 
  before 
  

   ignition 
  yielded 
  085 
  per 
  cent 
  of 
  soluble 
  silica, 
  and 
  after 
  igni- 
  

   tion 
  0*86 
  per 
  cent. 
  Here 
  again 
  no 
  silica 
  had 
  been 
  split 
  off 
  

   from 
  the 
  molecule, 
  and 
  practically 
  none 
  was 
  liberated 
  by 
  the 
  

   action 
  of 
  the 
  ammonium 
  chloride 
  upon 
  the 
  natrolite. 
  A 
  

   simple, 
  direct 
  substitution 
  of 
  ammonium 
  for 
  sodium 
  had 
  

   occurred. 
  

  

  Seolecite. 
  

  

  On 
  account 
  of 
  the 
  well-recognized 
  analogy 
  between 
  natrolite 
  

   and 
  seolecite, 
  the 
  latter 
  mineral 
  seemed 
  to 
  be 
  peculiarly 
  worthy 
  

   of 
  examination. 
  The 
  specimen 
  at 
  our 
  disposal 
  was 
  a 
  mass 
  of 
  

   stout, 
  radiating 
  needles, 
  which 
  was 
  collected 
  by 
  one 
  of 
  us 
  at 
  

   Whale 
  Cove, 
  on 
  the 
  island 
  of 
  Grand 
  Manan, 
  New 
  Brunswick. 
  

   Seolecite, 
  we 
  believe, 
  has 
  not 
  hitherto 
  been 
  recorded 
  from 
  this 
  

   locality 
  ; 
  and 
  on 
  this 
  account 
  alone 
  the 
  material 
  deserved 
  atten- 
  

   tion. 
  

  

  Three 
  sealed 
  tube 
  experiments 
  were 
  carried 
  out, 
  essentially 
  

   as 
  in 
  the 
  case 
  of 
  natrolite, 
  as 
  follows 
  : 
  

  

  A. 
  Heated 
  10 
  hours 
  at 
  350°. 
  13-74 
  per 
  cent 
  of 
  lime 
  and 
  0-35 
  of 
  

  

  soda 
  were 
  taken 
  out. 
  The 
  residue 
  contained 
  8 
  -78 
  per 
  cent 
  of 
  

   ammonia. 
  

  

  B. 
  Heated 
  10 
  hours 
  at 
  370°. 
  12-97 
  of 
  lime 
  and 
  0*22 
  of 
  soda 
  were 
  

  

  extracted. 
  8-48 
  per 
  cent 
  of 
  ammonia 
  in 
  the 
  residue. 
  On 
  

   account 
  of 
  the 
  excessive 
  temperature 
  of 
  this 
  experiment, 
  

   some 
  reversion 
  of 
  the 
  converted 
  material 
  had 
  taken 
  place. 
  

  

  C. 
  Heated 
  5 
  hours 
  at 
  340°-350°. 
  Leach 
  not 
  studied. 
  8*91 
  per 
  

  

  cent 
  of 
  ammonia 
  in 
  residue. 
  

  

  Analyses 
  of 
  the 
  seolecite 
  and 
  of 
  residues 
  B 
  and 
  C 
  are 
  given 
  

  

  below. 
  The 
  less 
  perfect 
  transformation 
  in 
  the 
  case 
  of 
  B 
  is 
  

   evident. 
  

  

  Seolecite. 
  Residue 
  B. 
  Residue 
  C. 
  

  

  Si0 
  2 
  ._ 
  _.. 
  45*86 
  53-39 
  53*69 
  

  

  A1 
  2 
  3 
  25-78 
  30-51 
  30"50 
  

  

  CaO 
  ... 
  13-92 
  -62 
  *42 
  

  

  Na 
  2 
  -41 
  undet. 
  -29 
  

  

  NH 
  3 
  . 
  8-48 
  8'91 
  

  

  H 
  2 
  at 
  100° 
  -40 
  -74 
  -12 
  

  

  HO 
  above 
  100° 
  13-65 
  6'28 
  6'52 
  

  

  100-02 
  100-02 
  100*45 
  

  

  The 
  product 
  of 
  the 
  reaction 
  is 
  plainly 
  the 
  same 
  as 
  that 
  

   obtained 
  from 
  natrolite, 
  and 
  the 
  identity 
  in 
  type 
  of 
  the 
  two 
  

  

  