﻿446 
  

  

  Pratt 
  and 
  Foote* 
  — 
  Wellsite, 
  a 
  new 
  Mineral. 
  

  

  

  and 
  the 
  precipitate 
  of 
  barium 
  chromate 
  was 
  washed 
  with 
  a 
  

   weak 
  chromate 
  solution 
  and 
  with 
  water. 
  The 
  precipitate 
  was 
  

   dissolved 
  in 
  2 
  CC 
  of 
  pure 
  dilute 
  nitric 
  acid, 
  which 
  was 
  then 
  partly 
  

   neutralized 
  with 
  ammonia. 
  Ammonium 
  acetate 
  was 
  added 
  

   and 
  10 
  cc 
  of 
  chromate 
  solution 
  as 
  before, 
  and 
  after 
  standing, 
  the 
  

   precipitate 
  was 
  filtered 
  on 
  a 
  Gooch 
  crucible 
  and 
  weighed 
  as 
  

   BaCr0 
  4 
  . 
  

  

  The 
  filtrate 
  from 
  the 
  barium 
  precipitation 
  was 
  concentrated 
  

   somewhat, 
  and 
  calcium 
  and 
  the 
  small 
  quantity 
  of 
  strontium 
  

   precipitated 
  as 
  before. 
  They 
  were 
  ignited 
  and 
  weighed 
  as 
  

   oxide. 
  Strontium 
  was 
  then 
  separated 
  by 
  treatment 
  with 
  amyl 
  

   alcohol 
  and 
  determined 
  as 
  sulphate. 
  

  

  The 
  alkalies 
  were 
  determined 
  by 
  a 
  Smith 
  fusion 
  in 
  the 
  ordi- 
  

   nary 
  way. 
  

  

  The 
  results 
  of 
  the 
  analyses 
  are 
  as 
  follows 
  : 
  

  

  Si0 
  2 
  43-62 
  

  

  A1 
  2 
  3 
  25-04 
  

  

  BaO 
  

  

  SrO. 
  

  

  CaO 
  

  

  MgO 
  

  

  5-00 
  

   1-12 
  

   5-76 
  

   0-61 
  

  

  K 
  2 
  

  

  Na 
  2 
  

  

  H 
  2 
  13-32 
  

  

  3-40 
  

   1-80 
  

  

  II. 
  

   44-11 
  

  

  24-89 
  

   5-15 
  

   1-18 
  

  

  5-84 
  

   0-62 
  

  

  13-39 
  

  

  Average. 
  

  

  43-86 
  

  

  24-96 
  

  

  5-07 
  

  

  1-15 
  

  

  5-80 
  

  

  0-62 
  

  

  3-40 
  

  

  1-80 
  

  

  13-35 
  

  

  100-01 
  

  

  "Ratio 
  

   731 
  

   244 
  

   033 
  

   011 
  

   104 
  

   015 
  

   036 
  

   029 
  J 
  

   742 
  

  

  J- 
  -228 
  

  

  l 
  

  

  I 
  

  

  3-00 
  

   1 
  -00 
  

  

  •93 
  

  

  = 
  3-04 
  

  

  The 
  ratio 
  of 
  Si0 
  2 
  : 
  A1 
  2 
  3 
  : 
  RO 
  : 
  H 
  2 
  is 
  very 
  close 
  to 
  3 
  : 
  1 
  : 
  1 
  : 
  3, 
  

   which 
  gives 
  the 
  formula 
  R"Al 
  2 
  Si 
  3 
  O 
  10 
  . 
  3H 
  2 
  0. 
  The 
  ratio 
  of 
  

   BaO 
  : 
  CaO 
  : 
  K 
  2 
  0+Na 
  2 
  in 
  the 
  above 
  analyses 
  is 
  nearly 
  1:3:2 
  

   and 
  the 
  theoretical 
  composition 
  calculated 
  for 
  this 
  ratio 
  is 
  given 
  

   below 
  together 
  with 
  the 
  analysis 
  after 
  substituting 
  for 
  E"a 
  2 
  

   its 
  equivalent 
  of 
  K 
  2 
  and 
  for 
  MgO 
  and 
  SrO 
  their 
  equivalents 
  

   respectively 
  of 
  CaO 
  and 
  BaO 
  and 
  then 
  recalculating 
  to 
  100 
  

   per 
  cent. 
  

  

  Si0 
  2 
  43-12 
  

  

  A1 
  2 
  3 
  24-54 
  

  

  BaO 
  __. 
  665 
  

  

  CaO 
  6-59 
  

  

  K 
  2 
  0.__. 
  _.. 
  5-98 
  

  

  HO... 
  _.. 
  13-12 
  

  

  100-00 
  

  

  Theory 
  for 
  R"Al 
  2 
  Si 
  3 
  O 
  10 
  

  

  . 
  3H 
  a 
  O 
  

  

  where 
  R 
  is 
  -iBa, 
  f 
  Ca, 
  

  

  |K. 
  

  

  42-87 
  

  

  

  24-27 
  

  

  

  6-62 
  

  

  

  7-27- 
  

  

  

  6-10 
  

  

  

  12-87 
  

  

  

  100-00 
  

  

  Experiments 
  were 
  made 
  to 
  determine 
  :at 
  what 
  temperatures 
  

   the 
  water 
  was 
  driven 
  off, 
  and 
  the 
  results 
  are 
  given 
  in 
  the 
  fol- 
  

   lowing 
  table, 
  the. 
  mineral 
  being 
  heated 
  in 
  each 
  case 
  s 
  until 
  the 
  

  

  