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  Pratt 
  and 
  Foote 
  — 
  Wellsite, 
  a 
  new 
  Mineral. 
  

  

  the 
  proportions 
  of 
  silica 
  and 
  water 
  have 
  a 
  constant 
  ratio, 
  1 
  : 
  1, 
  

   between 
  themselves, 
  except 
  in 
  the 
  case 
  of 
  phillipsite. 
  As 
  

   there 
  is, 
  however, 
  considerable 
  variation 
  in 
  the 
  analyses 
  of 
  

   phillipsite, 
  it 
  is 
  not 
  improbable 
  that 
  the 
  ratio 
  of 
  Si0 
  2 
  : 
  H 
  2 
  0, 
  

   given 
  as 
  4 
  : 
  4-J-, 
  should 
  be 
  in 
  some 
  cases 
  at 
  least, 
  4 
  : 
  4. 
  The 
  

   minerals 
  then 
  form 
  a 
  gradual 
  series, 
  increasing 
  in 
  the 
  propor- 
  

   tions 
  of 
  Si0 
  2 
  and 
  H 
  2 
  from 
  wellsite 
  to 
  stilbite. 
  

  

  Fresenius* 
  has 
  shown 
  that 
  this 
  group 
  of 
  minerals 
  may 
  be 
  

   regarded 
  as 
  a 
  series 
  in 
  which 
  the 
  ratio 
  of 
  RO 
  : 
  A1 
  2 
  3 
  is 
  con- 
  

   stant, 
  1 
  : 
  1, 
  while 
  the 
  silica 
  and 
  water 
  vary 
  between 
  certain 
  

   limits. 
  He 
  has 
  assumed 
  as 
  these 
  two 
  limits 
  : 
  

  

  RAl 
  2 
  Si 
  6 
  )6 
  + 
  6H 
  2 
  and 
  

  

  B 
  2 
  Al 
  4 
  Si 
  4 
  16 
  + 
  6H 
  2 
  

  

  The 
  first 
  would 
  be 
  a 
  hydrated 
  calcium 
  albite 
  and 
  the 
  last 
  a 
  

   hydrated 
  anorthite. 
  From 
  a 
  comparison 
  of 
  the 
  wellsite-stil- 
  

   bite 
  series, 
  it 
  seems 
  more 
  probable 
  that 
  the 
  anorthite 
  end 
  

   would 
  be 
  RAl 
  2 
  Si 
  2 
  8 
  + 
  2H 
  2 
  0, 
  or 
  doubling 
  this 
  for 
  better 
  com- 
  

   parison 
  with 
  the 
  formula 
  of 
  Fresenius, 
  R 
  2 
  Al 
  4 
  Si 
  4 
  16 
  -f 
  4H 
  8 
  0. 
  

  

  It 
  is 
  not 
  unreasonable 
  to 
  expect 
  that 
  the 
  first 
  or 
  anorthite 
  

   member 
  of 
  this 
  series 
  may 
  be 
  found 
  in 
  nature 
  and 
  the 
  com- 
  

   pleted 
  series 
  would 
  then 
  be 
  : 
  

  

  Anorthite 
  limit 
  RAl 
  2 
  Si 
  2 
  8 
  + 
  2H 
  2 
  (not 
  yet 
  identified) 
  

  

  Wellsite 
  . 
  RAl 
  2 
  Si 
  3 
  O 
  10 
  + 
  3H 
  2 
  O 
  

  

  Phillipsite 
  . 
  RAl 
  2 
  Si 
  4 
  12 
  + 
  4iH 
  2 
  (perhaps 
  4H 
  2 
  0) 
  

  

  Harmotome 
  RAl 
  2 
  Si 
  5 
  14 
  + 
  5H 
  2 
  

  

  Stilbite 
  RA] 
  2 
  Si 
  6 
  16 
  + 
  6H 
  2 
  

  

  It 
  is 
  also 
  interesting 
  to 
  note 
  that 
  the 
  formula 
  of 
  the 
  new 
  

   mineral 
  wellsite 
  is 
  the 
  same 
  as 
  that 
  assigned 
  to 
  edingtonite, 
  

   but 
  the 
  latter 
  is 
  essentially 
  a 
  barium 
  mineral 
  and 
  being 
  tetra- 
  

   gonal 
  shows 
  no 
  crystallographic 
  relations 
  to 
  wellsite. 
  

  

  Pyrognostics. 
  — 
  When 
  heated 
  before 
  the 
  blowpipe, 
  the 
  min 
  

   eral 
  exfoliates 
  slightly 
  and 
  fuses 
  at 
  2*5-3 
  to 
  a 
  white 
  bead, 
  

   coloring 
  the 
  flame 
  slightly 
  yellow. 
  In 
  the 
  closed 
  tube, 
  water 
  

   is 
  given 
  off 
  at 
  a 
  low 
  temperature. 
  It 
  is 
  very 
  readily 
  decom- 
  

   posed 
  by 
  hot 
  hydrochloric 
  acid 
  with 
  the 
  separation 
  of 
  silica, 
  

   but 
  without 
  gelatinization. 
  When 
  the 
  water 
  in 
  the 
  mineral 
  is 
  

   driven 
  off 
  below 
  265° 
  C, 
  it 
  is 
  nearly 
  all 
  regained 
  on 
  exposing 
  

   the 
  mineral 
  to 
  the 
  air. 
  If 
  the 
  water, 
  however, 
  is 
  driven 
  off 
  at 
  

   a 
  red 
  heat, 
  none 
  is 
  regained 
  by 
  the 
  mineral. 
  

  

  Name. 
  — 
  It 
  is 
  with 
  pleasure 
  that 
  the 
  authors 
  name 
  this 
  min- 
  

   eral 
  wellsite 
  in 
  honor 
  of 
  their 
  friend 
  Professor 
  H. 
  L. 
  Wells 
  of 
  

   the 
  Sheffield 
  Scientific 
  School. 
  

  

  In 
  conclusion, 
  the 
  authors 
  wish 
  to 
  express 
  their 
  thanks 
  to 
  

   Professor 
  S. 
  L. 
  Penfield 
  for 
  his 
  advice 
  and 
  suggestions 
  and 
  the 
  

   kind 
  interest 
  he 
  has 
  shown 
  during 
  the 
  investigation. 
  

  

  Mineralogical-Petrographical 
  Laboratory, 
  

   Sheffield 
  Scientific 
  School, 
  April, 
  1897. 
  

  

  *Zs. 
  Kr., 
  iii, 
  42, 
  18*78. 
  

  

  