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  Wells 
  and 
  Foote 
  — 
  Double 
  Fluorides 
  of 
  

  

  Art. 
  XLIX. 
  — 
  On 
  the 
  Double 
  Fluorides 
  of 
  Zirconium 
  with 
  

   Lithium, 
  Sodium 
  and 
  Thallium 
  ; 
  by 
  H. 
  L. 
  Wells 
  and 
  

   H. 
  W. 
  Foote. 
  

  

  In 
  a 
  previous 
  article* 
  we 
  have 
  described 
  the 
  csesium-zir- 
  

   conium 
  fluorides, 
  and 
  upon 
  comparing 
  these 
  with 
  the 
  corre- 
  

   sponding 
  ammonium 
  and 
  potassium 
  salts, 
  which 
  had 
  been 
  

   previously 
  described 
  by 
  Marignacf 
  it 
  was 
  observed 
  that 
  the 
  

   types 
  of 
  salts 
  formed 
  varied 
  with 
  the 
  molecular 
  weights 
  of 
  the 
  

   alkaline 
  fluorides 
  in 
  an 
  interesting 
  manner. 
  The 
  fluorides 
  of 
  

   smaller 
  molecular 
  weight 
  gave 
  types 
  with 
  a 
  larger 
  relative 
  num- 
  

   ber 
  of 
  these 
  molecules, 
  while 
  the 
  fluorides 
  of 
  higher 
  molecular 
  

   weights 
  combined 
  with 
  more 
  zirconium 
  fluoride 
  than 
  the 
  

   others. 
  This 
  relation 
  is 
  made 
  clear 
  from 
  the 
  following 
  table, 
  

   which 
  was 
  given 
  in 
  the 
  previous 
  article 
  referred 
  to 
  : 
  

  

  3 
  : 
  1 
  Type. 
  2 
  : 
  1 
  Type. 
  1 
  : 
  1 
  Type. 
  2 
  : 
  3 
  Type. 
  

  

  3NH 
  4 
  F.ZrF 
  4 
  2NH 
  4 
  F.ZrF 
  4 
  

  

  3KF.ZrF 
  4 
  2KF.ZrF 
  4 
  KF 
  . 
  ZrF 
  4 
  

  

  2CsF.ZrF, 
  CsF.ZrF, 
  2CsF. 
  3ZrF,. 
  2HO 
  

  

  The 
  present 
  investigation 
  was 
  undertaken 
  with 
  the 
  view, 
  

   in 
  the 
  first 
  place, 
  of 
  testing 
  the 
  apparent 
  rule 
  with 
  lithium 
  

   fluoride, 
  which 
  has 
  a 
  lower 
  molecular 
  weight 
  than 
  the 
  fluorides 
  

   previously 
  experimented 
  upon. 
  Our 
  expectations 
  were 
  real- 
  

   ized 
  by 
  the 
  preparation 
  of 
  the 
  salt 
  4LiF.ZrF 
  4 
  . 
  |H 
  2 
  0. 
  The 
  

   salt 
  2LiF 
  . 
  ZrF 
  4 
  was 
  also 
  obtained, 
  but, 
  in 
  spite 
  of 
  a 
  careful 
  

   search, 
  no 
  intermediate 
  3:1 
  salt 
  could 
  be 
  discovered. 
  The 
  

   following 
  table, 
  giving 
  the 
  lithium, 
  potassium 
  and 
  caesium 
  salts, 
  

   shows 
  a 
  perfectly 
  symmetrical 
  gradation 
  in 
  types 
  according 
  to 
  

   the 
  atomic 
  weights 
  of 
  the 
  alkali 
  metals, 
  except 
  that 
  the 
  inter- 
  

   mediate 
  lithium 
  salt 
  is 
  missing. 
  

  

  Potassium 
  salts. 
  

   Type. 
  Lithium 
  salts. 
  (Marignac.) 
  Caesium 
  salts. 
  

  

  4:1 
  4LiF.ZrF 
  4 
  .|H 
  2 
  - 
  

  

  3:1 
  ...... 
  3KF.ZrF 
  4 
  

  

  2:1 
  2LiF.ZrF 
  4 
  2KF.ZrF 
  4 
  2CsF.ZrF 
  4 
  

  

  1:1 
  KF.ZrF 
  4 
  .H 
  2 
  CsF.ZrF 
  4 
  .H 
  2 
  

  

  2:3 
  _-. 
  2CsF.3ZrF 
  4 
  .2H 
  2 
  

  

  Marignac's 
  two 
  ammonium 
  salts, 
  3 
  : 
  1 
  and 
  2 
  : 
  1, 
  also 
  enter 
  

   the 
  series 
  symmetrically. 
  

  

  We 
  have 
  investigated 
  also 
  the 
  thallous-zirconium 
  fluorides, 
  

   since 
  the 
  high 
  atomic 
  weight 
  of 
  thallium 
  led 
  us 
  to 
  expect 
  that 
  

   it 
  would 
  possibly 
  yield 
  a 
  series 
  of 
  salts 
  symmetrical 
  with 
  those 
  

  

  * 
  This 
  Journal, 
  IV, 
  i, 
  18. 
  f 
  Ann. 
  Chim. 
  Phys., 
  ix, 
  257. 
  

  

  