﻿206 
  M. 
  Austin 
  — 
  Double 
  Ammonium 
  Phosphates. 
  

  

  Art. 
  XXI. 
  — 
  The 
  Double 
  Am^monium 
  Phosphates 
  of 
  Beryl- 
  

   lium^ 
  Zinc^ 
  and 
  Cadmiu-m 
  in 
  Analysis; 
  by 
  Martha 
  

   Austin. 
  

  

  [Contribution 
  from 
  the 
  Kent 
  Chemical 
  Laboratory 
  of 
  Yale 
  University 
  — 
  LXXXVI.] 
  

  

  It 
  has 
  been 
  shown* 
  that 
  the 
  composition 
  of 
  the 
  phosphate 
  

   of 
  manganese 
  thrown 
  down 
  by 
  microcosmic 
  salt 
  from 
  the 
  

   solution 
  of 
  a 
  pure 
  manganous 
  salt 
  contains 
  more 
  manganese 
  

   than 
  belongs 
  to 
  the 
  ideal 
  ammonium 
  manganese 
  phosphate 
  

   NH.MnPO^ 
  ; 
  and, 
  further, 
  that 
  by 
  acting 
  with 
  ammonium 
  

   chloride 
  in 
  proper 
  proportion 
  the 
  phosphate 
  of 
  manganese 
  

   thrown 
  down 
  by 
  microcosmic 
  salt 
  may 
  be 
  completely 
  converted 
  

   to 
  the 
  ideal 
  ammonium 
  manganese 
  phosphate. 
  Ammonium 
  

   chloride, 
  likewise, 
  in 
  the 
  case 
  of 
  magnesium 
  phosphatef 
  tends 
  

   to 
  cause 
  the 
  replacement 
  of 
  the 
  metal 
  by 
  ammonia. 
  Indeed, 
  

   the 
  replacement 
  here 
  is 
  readily 
  carried 
  so 
  far 
  beyond 
  the 
  point 
  

   corresponding 
  to 
  the 
  normal 
  ammonium 
  magnesium 
  phosphate^ 
  

   JSTH^MgPO^, 
  that 
  the 
  tendency 
  to 
  form 
  a 
  salt 
  richer 
  in 
  

   ammonia 
  and 
  poorer 
  in 
  magnesium 
  — 
  perhaps 
  something 
  like 
  

   Mg(NII^)4(P()^)2 
  — 
  must 
  be 
  recognized. 
  

  

  These 
  facts 
  suggested 
  an 
  investigation 
  into 
  the 
  constitution 
  

   of 
  certain 
  other 
  ammonium 
  phosphates 
  with 
  reference 
  to 
  their 
  

   utility 
  in 
  analytical 
  processes. 
  Of 
  the 
  elements 
  of 
  Mendeleeff 
  s 
  

   second 
  group, 
  beryllium, 
  magnesium, 
  zinc, 
  cadmium 
  and 
  mer- 
  

   cury 
  are 
  capable 
  of 
  yielding 
  double 
  ammonium 
  phosphates, 
  

   while 
  no 
  such 
  compounds 
  of 
  calcium, 
  strontium 
  and 
  barium 
  

   have 
  been 
  described. 
  The 
  solubility 
  in 
  ammonia 
  of 
  the 
  double 
  

   ammonium 
  phosphates 
  of 
  the 
  elements 
  of 
  the 
  former 
  category 
  

   appears 
  to 
  increase 
  as 
  the 
  elements 
  of 
  which 
  they 
  are 
  com- 
  

   pounds 
  are 
  removed 
  in 
  the 
  series 
  from 
  the 
  beryllium, 
  and, 
  

   while 
  the 
  same 
  is 
  true 
  of 
  the 
  simple 
  phosphates 
  of 
  members 
  of 
  

   the 
  latter 
  category, 
  the 
  extent 
  of 
  such 
  solvent 
  action 
  is 
  slight 
  

   comparatively. 
  According 
  to 
  the 
  work 
  recorded 
  in 
  the 
  litera- 
  

   ture, 
  calcium, 
  barium, 
  and 
  strontium 
  form 
  individually 
  a 
  

   neutral 
  tribasic 
  phosphate 
  or 
  acid 
  phosphates 
  of 
  greater 
  or 
  less 
  

   degree 
  of 
  acidity 
  according 
  to 
  the 
  conditions 
  of 
  precipitation. 
  

   In 
  my 
  experience 
  where 
  salts 
  of 
  these 
  elements 
  were 
  precipi- 
  

   tated 
  either 
  with 
  ammonium 
  phosphate 
  or 
  microcosmic 
  salt 
  in 
  

   presence 
  of 
  varying 
  amounts 
  of 
  ammonium 
  chloride, 
  or 
  ammo- 
  

   nia, 
  or 
  both, 
  only 
  the 
  recognized 
  phosphates 
  were 
  obtained. 
  

   The 
  effect 
  of 
  ammonium 
  salts 
  in 
  presence 
  of 
  ammonia 
  seemed 
  

   to 
  promote 
  the 
  formation 
  of 
  the 
  tribasic 
  salt 
  in 
  the 
  case 
  of 
  

   calcium 
  and 
  strontium 
  ; 
  barium 
  tends 
  to 
  form 
  the 
  barium 
  acid 
  

   phosphate 
  almost 
  exclusively 
  even 
  in 
  the 
  presence 
  of 
  ammonium 
  

  

  * 
  This 
  Journal, 
  vol. 
  vi, 
  233. 
  f 
  This 
  Journal, 
  vol. 
  vii, 
  187. 
  

  

  