﻿M. 
  Austin 
  — 
  Double 
  Ammonium 
  Phosphates. 
  213 
  

  

  the 
  ammonium 
  phosphate, 
  and 
  the 
  solution 
  was 
  made 
  just 
  

   ammoniacal 
  to 
  litmus 
  with 
  a 
  few 
  drops 
  of 
  dilute 
  ammonia 
  

   both 
  before 
  and 
  after 
  heating 
  to 
  convert 
  it 
  to 
  crystalline 
  condi- 
  

   tion. 
  Experiment 
  (15) 
  shows 
  that 
  precipitation 
  is 
  not 
  com- 
  

   plete 
  under 
  these 
  conditions. 
  The 
  zinc 
  left 
  in 
  the 
  solution 
  

   was 
  precipitated 
  at 
  once 
  as 
  sulphide, 
  and 
  estimated 
  as 
  the 
  

   oxide, 
  after 
  dissolving 
  in 
  hydrochloric 
  acid 
  and 
  precipitating 
  

   with 
  sodium 
  carbonate. 
  In 
  (16) 
  of 
  the 
  table 
  the 
  first 
  filtrate 
  

   was 
  treated 
  with 
  an 
  excess 
  of 
  microcosmic 
  salt, 
  and 
  boiled. 
  

   Another 
  portion 
  of 
  the 
  ammonium 
  zinc 
  phosphate 
  was 
  pre- 
  

   cipitated, 
  and 
  was 
  filtered 
  off 
  and 
  estimated. 
  'No 
  zinc 
  was 
  

   found 
  bj 
  sulphuretted 
  hydrogen 
  in 
  the 
  second 
  filtrate. 
  

  

  

  

  

  Table 
  III. 
  

  

  

  

  

  

  

  

  

  ZnsP^Ov 
  

  

  

  

  

  Zd^PqOt 
  

  

  

  

  correspond 
  

  

  

  

  

  corresponding 
  

  

  

  Error 
  

  

  ing 
  to 
  Zn 
  

  

  

  

  Time 
  of 
  

  

  to 
  ZnS04. 
  

  

  

  

  in 
  terms 
  

  

  eft 
  in 
  the 
  

  

  

  

  stand- 
  

  

  Taken. 
  

  

  Found. 
  

  

  Error. 
  

  

  of 
  Zinc. 
  

  

  filtrate. 
  

  

  (NH4)3PO,. 
  

  

  NH4CI 
  

  

  ing. 
  

  

  grm. 
  

  

  grm. 
  

  

  grm. 
  

  

  grm. 
  

   A 
  

   0-0060- 
  

  

  grm. 
  

  

  grm. 
  

  

  grm. 
  

  

  hours. 
  

  

  ( 
  1) 
  0-6355 
  

  

  0-6200 
  

  

  0-0149- 
  

  

  trace 
  

  

  3 
  13 
  

  

  

  H 
  

  

  ( 
  2) 
  0-6355 
  

  

  0-6254 
  

  

  0-0101- 
  

  

  0-0040- 
  

  

  trace 
  

  

  313 
  

  

  

  

  16 
  

  

  ( 
  3) 
  0-6355 
  

  

  0-6300 
  

  

  0-0055- 
  

  

  0-0022- 
  

  

  trace 
  

  

  3-13 
  

  

  .... 
  

  

  16 
  

  

  

  

  

  B 
  

  

  

  HNaNH4P04 
  

  

  

  

  

  

  

  

  .4H2O 
  

  

  

  

  

  

  

  

  

  grm. 
  

  

  

  

  ( 
  4) 
  6355 
  

  

  0-6271 
  

  

  00084- 
  

  

  0-0034- 
  

  

  trace 
  

  

  4-47 
  

  

  0-5 
  

  

  1 
  

  

  ( 
  5) 
  6355 
  

  

  0-6256 
  

  

  00099- 
  

  

  00040- 
  

  

  C 
  

   0-0028- 
  

  

  none 
  

  

  4-47 
  

  

  0-5 
  

  

  20 
  

  

  ( 
  6) 
  0-6355 
  

  

  0-62S5 
  

  

  0-0070- 
  

  

  none 
  

  

  4-47 
  

  

  10 
  

  

  i 
  

  

  ( 
  7) 
  0-6355 
  

  

  0-6304 
  

  

  0-0051- 
  

  

  0-0020- 
  

  

  none 
  

  

  4-47 
  

  

  10 
  

  

  f 
  

  

  ( 
  8) 
  0-6355 
  

  

  0-6295 
  

  

  0-0060- 
  

  

  0-0024- 
  

  

  none 
  

  

  4-47 
  

  

  10 
  

  

  H 
  

  

  ( 
  9) 
  0-6355 
  

  

  0-6335 
  

  

  0-0020- 
  

  

  00008- 
  

  

  none 
  

  

  4-47 
  

  

  10 
  

  

  16 
  

  

  (10) 
  0-6355 
  

  

  0-6381 
  

  

  0-0026 
  + 
  

  

  0-0010 
  + 
  

  

  none 
  

  

  4-47 
  

  

  20 
  

  

  i 
  

  

  (11) 
  0-6355 
  

  

  0-6379 
  

  

  0-U024 
  + 
  

  

  0-0009 
  + 
  

  

  none 
  

  

  4-47 
  

  

  20 
  

  

  2 
  

  

  (12) 
  0-6355 
  

  

  0-6386 
  

  

  0-0031 
  + 
  

  

  00012 
  + 
  

  

  none 
  

  

  4-47 
  

  

  20 
  

  

  i 
  

  

  (13) 
  0-6355 
  

  

  0-6393 
  

  

  0-0038 
  + 
  

  

  0-0014 
  + 
  

  

  none 
  

  

  4-47 
  

  

  20 
  

  

  i 
  

  

  (14) 
  0-6367 
  

  

  0-6355 
  

  

  0-0012 
  + 
  

  

  0-0005 
  + 
  

   D 
  

   0-0072- 
  

  

  none 
  

  

  4-47 
  

  

  30 
  

  

  16 
  

  

  (15) 
  0-6355 
  

  

  0-6172 
  

  

  0-0183- 
  

  

  0-0108 
  

  

  0-894 
  

  

  20 
  

  

  3 
  

  

  (16) 
  0-6355 
  

  

  10-6227 
  

   II 
  0-0040 
  

  

  00098- 
  

  

  0-0039- 
  

  

  E 
  

  

  0-0034- 
  

  

  none 
  

  

  I 
  0-894 
  

   II 
  3-576 
  

  

  20 
  

  

  ■ 
  i 
  

  

  (17) 
  0-6355 
  

  

  0-6270 
  

  

  0-0085- 
  

  

  none 
  

  

  4-47 
  

  

  

  3 
  

  

  (18) 
  0-6355 
  

  

  6125 
  

  

  0-0230- 
  

  

  0-0093- 
  

  

  00148 
  

  

  4-47 
  

  

  

  

  18 
  

  

  (19) 
  0-6355 
  

  

  0-6303 
  

  

  00052- 
  

  

  0-0021- 
  

  

  00020 
  

  

  4-47 
  

  

  10 
  

  

  18 
  

  

  From 
  the 
  results 
  it 
  seems 
  obvious 
  also 
  that 
  an 
  excess 
  of 
  the 
  

   soluble 
  phosphate 
  is 
  necessary 
  to 
  complete 
  the 
  precipitation 
  of 
  

   the 
  zinc 
  as 
  the 
  ammonium 
  zinc 
  phosphate 
  instead 
  of 
  partly 
  

   ammonium 
  zinc 
  phosphate 
  and 
  partly 
  tribasic 
  phosphate. 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Yol. 
  VIII, 
  No. 
  45.— 
  September, 
  1899. 
  

   15 
  

  

  