﻿216 
  M. 
  Austin 
  — 
  Doxible 
  Ammonium 
  Phosphates. 
  

  

  phosphate 
  too 
  rich 
  in 
  ammonia. 
  Either 
  acid 
  or 
  ammonia 
  in 
  

   small 
  amount 
  dissolves 
  the 
  salt, 
  as 
  is 
  shown 
  in 
  (14) 
  and 
  (15). 
  

  

  The 
  results 
  of 
  this 
  investigation 
  as 
  to 
  the 
  analytical 
  applica- 
  

   tion 
  of 
  the 
  double 
  ammonium 
  phosphates 
  of 
  beryllium, 
  zinc, 
  

   and 
  cadmium 
  may 
  be 
  summarized 
  briefly 
  as 
  follows 
  : 
  It 
  is 
  

   impossible 
  to 
  estimate 
  beryllium 
  with 
  accuracy 
  as 
  the 
  pyro- 
  

   phosphate 
  obtained 
  by 
  igniting 
  the 
  double 
  ammonium 
  phos- 
  

   phate 
  precipitated 
  from 
  beryllium 
  solutions 
  by 
  microcosmic 
  

   salt 
  or 
  ammonium 
  phosphate 
  in 
  presence 
  of 
  ammonium 
  chlor- 
  

   ide. 
  In 
  presence 
  of 
  the 
  proper 
  amount 
  of 
  ammonium 
  chloride 
  

   (10 
  grm. 
  to 
  20 
  grm. 
  in 
  lOO'^'" 
  -200"°^' 
  of 
  liquid) 
  zinc 
  ammonium 
  

   phosphate 
  can 
  be 
  obtained 
  in 
  the 
  ideal 
  condition, 
  which 
  on 
  

   ignition 
  yields 
  the 
  pyrophosphate. 
  This 
  method 
  may 
  serve, 
  

   therefore, 
  for 
  the 
  accurate 
  estimation 
  of 
  zinc. 
  

  

  Cadmium 
  may 
  be 
  estimated 
  with 
  accuracy 
  as 
  the 
  pyrophos- 
  

   phate 
  if 
  the 
  precipitate- 
  by 
  microcosmic 
  salt 
  in 
  the 
  nearly 
  neu- 
  

   tral 
  solution 
  containing 
  ammonium 
  chloride 
  in 
  the 
  proportion 
  

   of 
  ten 
  grams 
  to 
  one 
  hundred 
  cubic 
  centimeters 
  is 
  allowed 
  to 
  

   stand 
  several 
  hours 
  before 
  filtering. 
  In 
  this 
  way 
  all 
  cadmium 
  

   separates 
  out 
  from 
  the 
  solution 
  as 
  a 
  beautiful 
  crystalline 
  mass 
  

   of 
  cadmium 
  ammonium 
  phosphate 
  of 
  ideal 
  constitution. 
  The 
  

   conditions 
  must, 
  however, 
  be 
  preserved 
  with 
  care 
  ; 
  there 
  must 
  

   be 
  no 
  excess 
  of 
  ammonia, 
  no 
  free 
  acid, 
  and 
  no 
  excess 
  of 
  ammo- 
  

   nium 
  salt 
  beyond 
  the 
  quantity 
  indicated, 
  while 
  that 
  amount 
  is 
  

   necessary. 
  

  

  