﻿M. 
  AifjStin 
  — 
  Double 
  Ammoniitm 
  Phosphates. 
  

  

  209 
  

  

  precipitate 
  the 
  beryllium 
  as 
  the 
  double 
  ammonium 
  phosphate 
  

   from 
  the 
  results 
  recorded 
  in 
  section 
  D 
  of 
  the 
  table, 
  where, 
  

   after 
  the 
  precipitate 
  of 
  beryllium 
  phosphate 
  had 
  subsided 
  and 
  

   the 
  supernatant 
  liquid 
  had 
  been 
  poured 
  off, 
  the 
  precipitate 
  dis- 
  

   solved 
  in 
  hydrochloric 
  acid 
  was 
  brought 
  down 
  again 
  at 
  the 
  

   boiling 
  temperature 
  with 
  ammonia 
  either 
  alone 
  or 
  in 
  presence 
  

   of 
  ammonium 
  chloride. 
  The 
  results 
  obtained 
  show 
  that 
  the 
  

   salt 
  approaches 
  the 
  constitution 
  of 
  the 
  tribasic 
  phosphate, 
  

   when 
  it 
  is 
  precipitated 
  in 
  presence 
  of 
  a 
  faint 
  excess 
  of 
  phos- 
  

   phoric 
  acid, 
  even 
  though 
  ammonium 
  chloride 
  in 
  large 
  amount 
  

   be 
  present. 
  

  

  Table 
  I. 
  

  

  Be2P20T 
  

   corresponding 
  

  

  to 
  BeCls. 
  

   Taken. 
  Pound. 
  

  

  grm. 
  

  

  (1) 
  0-3578 
  

  

  (2) 
  3578 
  

  

  (3) 
  0-3578 
  

  

  (4) 
  0-3578 
  

  

  (5) 
  0-3578 
  

  

  grm. 
  

  

  0-3613 
  

   3808 
  

   0-3707 
  

   0-3640 
  

   0-3680 
  

  

  Error, 
  

   grm. 
  

  

  0-0035 
  + 
  

   0-0230 
  + 
  

   00129 
  + 
  

   0062 
  + 
  

   0-0102 
  + 
  

  

  BeaPo.Os 
  

  

  corresponding 
  

  

  to 
  BeCla. 
  

  

  Taken. 
  Foand. 
  

  

  grm. 
  

  

  A. 
  

  

  grtn. 
  

  

  Error, 
  

   grm. 
  

  

  (.VH,)3P04. 
  

  

  grm. 
  

  

  2 
  

   2 
  

   2 
  

  

  NH4CI 
  

   grm. 
  

  

  30 
  

  

  (6) 
  0-3578 
  0-3697 
  00119 
  + 
  

  

  (7) 
  0-3578 
  

  

  (8) 
  0-3578 
  

  

  (9) 
  0-3578 
  

   (10) 
  0-3578 
  

  

  (11) 
  

   (12) 
  

   (13) 
  

   (14) 
  

  

  0-3618 
  

   0-3680 
  

   0-3729 
  

   3631 
  

  

  0-0040 
  + 
  

   0-0102 
  + 
  

   00151 
  + 
  

   00053 
  + 
  

  

  HNaNH4P04 
  

   .4H2O 
  

  

  1-2 
  

   1-2 
  

   1-2 
  

   1-2 
  

  

  10 
  

   60 
  

  

  D. 
  

  

  0-2700 
  0-2589 
  0-0111- 
  0-5 
  

  

  0-2700 
  0-2989 
  0289+ 
  0-5 
  —10 
  

  

  0-2700 
  2936 
  0-0236+ 
  05 
  5-60 
  

  

  0-2700 
  0-2507 
  00193— 
  0-5 
  —60 
  

  

  From 
  the 
  work 
  described 
  it 
  is 
  clear 
  that 
  the 
  ammonium 
  

   beryllium 
  phosphate 
  is 
  not 
  obtained 
  in 
  ideal 
  condition 
  by 
  pre- 
  

   cipitating 
  a 
  solution 
  of 
  the 
  chloride 
  with 
  ammonium 
  phosphate. 
  

   Roessler's 
  own 
  results 
  were 
  likewise 
  only 
  approximately 
  cor- 
  

   rect, 
  as 
  he 
  states. 
  It 
  is 
  also 
  plain 
  that 
  hydrogen 
  sodium 
  

   ammonium 
  phosphate 
  precipitates 
  the 
  ammonium 
  beryllium 
  

   phosphate 
  in 
  a 
  condition 
  as 
  nearly 
  ideal 
  as 
  does 
  the 
  ammonium 
  

   phosphate, 
  while 
  the 
  effect 
  of 
  the 
  ammonium 
  chloride 
  in 
  either 
  

   case 
  is 
  not 
  marked 
  in 
  producing 
  a 
  phosphate 
  containing 
  

   ammonia. 
  Of 
  most 
  importance 
  in 
  obtaining 
  the 
  ammonium 
  

   salt 
  is 
  an 
  excess 
  of 
  the 
  soluble 
  phosphate, 
  for 
  when 
  the 
  amount 
  

   of 
  the 
  precipitant 
  is 
  reduced 
  to 
  a 
  little 
  more 
  than 
  the 
  theoretical 
  

   amount 
  the 
  condition 
  of 
  the 
  phosphate 
  coincides 
  almost 
  exactly 
  

   with 
  the 
  theory 
  for 
  the 
  tribasic 
  phosphate, 
  even 
  though 
  a 
  large 
  

  

  