﻿30 
  

  

  Norton 
  — 
  Estimation 
  of 
  Iron 
  in 
  the 
  Ferric 
  State. 
  

  

  

  

  

  

  Table 
  IV. 
  

  

  

  

  

  

  Fe^Oo 
  

  

  Fe.On 
  

  

  Dilu- 
  

  

  

  Excess 
  

  

  FeaOa 
  

  

  

  

  taken. 
  corrected. 
  

  

  tion. 
  

  

  HCl. 
  

  

  NaoS^Os. 
  

  

  found. 
  

  

  Error. 
  

  

  

  grras. 
  

  

  grms. 
  

  

  cm^. 
  

  

  cm^. 
  

  

  cm'. 
  

  

  grms. 
  

  

  grms. 
  

  

  30. 
  

  

  •0125 
  

  

  •0125 
  

  

  200 
  

  

  * 
  

  

  23^5 
  

  

  •0125 
  

  

  -0000 
  

  

  31. 
  

  

  •0250 
  

  

  •0250 
  

  

  400 
  

  

  i 
  

  

  21-98 
  

  

  •0250 
  

  

  -0000 
  

  

  32. 
  

  

  •0250 
  

  

  •0250 
  

  

  400 
  

  

  i 
  

  

  17^ 
  

  

  -0250 
  

  

  -0000 
  

  

  33. 
  

  

  •0250 
  

  

  •0250 
  

  

  400 
  

  

  1. 
  

  

  4 
  

  

  17- 
  

  

  •0250 
  

  

  •0000 
  

  

  34. 
  

  

  •0500 
  

  

  •0499 
  

  

  400 
  

  

  * 
  

  

  24- 
  

  

  •0498 
  

  

  •0001 
  — 
  

  

  35. 
  

  

  •0500 
  

  

  •0499 
  

  

  400 
  

  

  i 
  

  

  19- 
  

  

  •0498 
  

  

  •0001 
  — 
  

  

  36. 
  

  

  •0500 
  

  

  •0499 
  

  

  400 
  

  

  4 
  

  

  15-1 
  

  

  •0497 
  

  

  •0002 
  — 
  

  

  37. 
  

  

  •0500 
  

  

  •0499 
  

  

  400 
  

  

  i 
  

  

  19^ 
  

  

  •0498 
  

  

  -0001- 
  

  

  38. 
  

  

  •1001 
  

  

  •0999 
  

  

  400 
  

  

  

  23-1 
  

  

  -0993 
  

  

  •0006- 
  

  

  39. 
  

  

  •1001 
  

  

  0999 
  

  

  400 
  

  

  

  17-93 
  

  

  •0997 
  

  

  •0002 
  — 
  

  

  40. 
  

  

  •1001 
  

  

  0999 
  

  

  400 
  

  

  

  22^92 
  

  

  •0997 
  

  

  •0002 
  — 
  

  

  41. 
  

  

  •1001 
  

  

  0999 
  

  

  400 
  

  

  

  18^ 
  

  

  •0997 
  

  

  •0002 
  — 
  

  

  42. 
  

  

  •1001 
  

  

  0999 
  

  

  400 
  

  

  

  16^ 
  

  

  •0996 
  

  

  •0003 
  — 
  

  

  43. 
  

  

  •1498 
  

  

  1495 
  

  

  600 
  

  

  14 
  

  

  23-26 
  

  

  •1493 
  

  

  •0002- 
  

  

  44. 
  

  

  •1498 
  

  

  1495 
  

  

  600 
  

  

  U 
  

  

  16-66 
  

  

  •1493 
  

  

  •0002- 
  

  

  45. 
  

  

  •1498 
  

  

  1495 
  

  

  600 
  

  

  H 
  

  

  26-87 
  

  

  -1475 
  

  

  •0020- 
  

  

  46. 
  

  

  •1996 
  

  

  1992 
  

  

  800 
  

  

  2 
  

  

  22-38 
  

  

  •1990 
  

  

  •0002 
  — 
  

  

  47. 
  

  

  •1996 
  

  

  1992 
  

  

  800 
  

  

  2 
  

  

  17-29 
  

  

  -1999 
  

  

  •0007 
  + 
  

  

  48. 
  

  

  •1996 
  

  

  1992 
  

  

  800 
  

  

  2 
  

  

  22^20 
  

  

  -1991 
  

  

  •0001 
  — 
  

  

  49. 
  

  

  •4045 
  

  

  4037 
  

  

  1600 
  

  

  4 
  

  

  16-03 
  

  

  -4042 
  

  

  •0005 
  + 
  

  

  50. 
  

  

  •4045 
  

  

  4037 
  

  

  1600 
  

  

  4 
  

  

  16-2 
  

  

  -4023 
  

  

  •0014- 
  

  

  51. 
  

  

  •4018 
  

  

  4010 
  

  

  1600 
  

  

  4 
  

  

  16-34 
  

  

  -4007 
  

  

  •0003- 
  

  

  52. 
  

  

  •5051 
  

  

  5041 
  

  

  1800 
  

  

  4 
  

  

  15-27 
  

  

  -5026 
  

  

  -0015 
  — 
  

  

  As 
  seen 
  in 
  the 
  table 
  this 
  process 
  is 
  very 
  accurate, 
  especially 
  

   in 
  the 
  use 
  of 
  small 
  amounts 
  of 
  ferric 
  oxide. 
  The 
  introduc- 
  

   tion 
  of 
  cupric 
  sulphate 
  as 
  recommended 
  by 
  Oudemanns, 
  or 
  of 
  

   sodium 
  salicylate 
  according 
  to 
  Haswell's 
  method, 
  seems 
  to 
  be 
  

   unnecessary 
  and 
  only 
  complicates 
  the 
  process. 
  

  

  In 
  treating 
  ferric 
  oxide, 
  the 
  following 
  method 
  of 
  procedure 
  

  

  is 
  recommended. 
  Dissolve 
  an 
  amount 
  not 
  exceeding 
  0-2 
  grm. 
  

  

  of 
  the 
  oxide 
  in 
  hydrochloric 
  acid, 
  evaporate 
  to 
  a 
  pasty 
  mass, 
  

  

  dilute 
  to 
  about 
  800''"'' 
  with 
  freshly 
  boiled 
  water, 
  add 
  a 
  drop 
  of 
  

  

  potassium 
  sulphocyanide, 
  and 
  into 
  this 
  solution 
  run 
  50^'"^ 
  of 
  

  

  rh 
  

   approximately 
  — 
  sodium 
  thiosulphate 
  ; 
  allow 
  the 
  liquid 
  to 
  

  

  stand 
  until 
  perfectly 
  colorless 
  and 
  determine 
  the 
  excess 
  of 
  thio- 
  

  

  sulphate 
  by 
  — 
  iodine 
  and 
  starch. 
  For 
  quantities 
  of 
  iron 
  oxide 
  

  

  up 
  to 
  0'2 
  of 
  a 
  grm. 
  this 
  process 
  is 
  quick 
  and 
  most 
  accurate 
  ; 
  

   when 
  care 
  is 
  taken 
  to 
  preserve 
  the 
  relations 
  of 
  acidity 
  and 
  

   dilution, 
  twice 
  the 
  amount 
  of 
  ferric 
  oxide 
  mentioned 
  above 
  

   may 
  be 
  handled. 
  

  

  In 
  conclusion 
  I 
  wish 
  to 
  thank 
  Prof. 
  F. 
  A. 
  Gooch 
  for 
  his 
  

   kind 
  advice 
  and 
  many 
  suggestions. 
  

  

  