﻿Xo. 
  

  

  5 
  

  

  6 
  

  

  8 
  

  

  9 
  

  

  10 
  

  

  13 
  

  

  14 
  

  

  15 
  

  

  17 
  

  

  11 
  

  

  12 
  

  

  d 
  Merwin 
  — 
  Hydrated 
  1 
  

  

  ?erric 
  Oxides. 
  335 
  

  

  Table 
  VI. 
  

  

  

  _ 
  . 
  mineral 
  25° 
  

  

  

  Specific 
  gravity 
  water 
  250 
  

  

  Name 
  of 
  mineral 
  

  

  in 
  water 
  in 
  xylol 
  

  

  as 
  received 
  

  

  4-263 
  4-266 
  

  

  Goetliite 
  

  

  4-250 
  

  

  Goetliite 
  

  

  4172 
  

  

  Limonite 
  

  

  4107 
  (4-093) 
  

  

  Goethite 
  

  

  4-091 
  (4-087) 
  

  

  Goethite 
  

  

  3-970 
  

  

  Limonite 
  

  

  3-895 
  

  

  Limonite 
  

  

  3-951 
  (3-878) 
  

  

  Limonite 
  

  

  3-822 
  

  

  Limonite 
  

  

  3-854 
  

  

  Lepidocroeite 
  

  

  3-841 
  

  

  Lepidocrocite 
  

  

  The 
  corrections 
  of 
  the 
  specific 
  gravity 
  determinations 
  

   were 
  made 
  on 
  the 
  basis 
  of 
  the 
  analyses 
  and 
  in 
  accordance 
  

   with 
  the 
  evidence 
  presented 
  by 
  the 
  dehydration 
  experi- 
  

   ments 
  that 
  the 
  specimens 
  were 
  monohydrates 
  of 
  ferric 
  

   oxide. 
  The 
  analyses, 
  as 
  will 
  be 
  remembered, 
  indicated 
  

   as 
  chief 
  impurities 
  silica 
  (amorphous 
  except 
  in 
  No. 
  5 
  and 
  

   No. 
  6) 
  and 
  probably 
  ferrous 
  carbonate 
  and 
  manganite. 
  

   For 
  water 
  in 
  excess 
  of 
  the 
  amount 
  required 
  to 
  form 
  the 
  

   monohydrate 
  with 
  the 
  ferric 
  oxide 
  a 
  correction 
  was 
  made 
  

   on 
  the 
  assumption 
  that 
  the 
  water 
  was 
  free. 
  The 
  value 
  

   taken 
  for 
  the 
  specific 
  gravity 
  of 
  amorphous 
  silica 
  was 
  2-3 
  ; 
  

   for 
  quartz 
  2-65 
  ; 
  for 
  ferrous 
  carbonate 
  3-88, 
  and 
  for 
  man- 
  

   ganite 
  4-4. 
  The 
  approximate 
  composition 
  of 
  the 
  minerals 
  

   and 
  the 
  specific 
  gravities 
  of 
  the 
  monohydrates 
  of 
  ferric 
  

   oxide 
  corrected 
  on 
  that 
  basis 
  are 
  given 
  in 
  Table 
  VII. 
  

  

  N 
  T 
  o. 
  

  

  /—Approximate 
  compositi 
  

  

  % 
  Fe,0 
  3 
  . 
  % 
  MnoO 
  

  

  H 
  2 
  % 
  FeCO, 
  H 
  2 
  6 
  

  

  Table 
  VII. 
  

   on 
  of 
  mineral-^ 
  

   %Si0 
  2 
  %H,0 
  

  

  Sp. 
  gr. 
  at 
  

   25° 
  for 
  

   Fe 
  2 
  3 
  - 
  

   H 
  2 
  Name 
  as 
  labeled 
  

  

  5 
  

  

  99-65 
  

  

  

  

  0-36 
  

  

  0-10 
  

  

  4-29 
  

  

  Goetliite 
  

  

  6 
  

  

  9908 
  

  

  

  

  0-70 
  

  

  0-17 
  

  

  4-29 
  

  

  Goetliite 
  

  

  8 
  

  

  98-15 
  

  

  

  

  1-07 
  

  

  0-63 
  

  

  4-30 
  

  

  Limonite 
  

  

  9 
  

  

  97-44 
  

  

  

  

  117 
  

  

  108 
  

  

  4-28 
  

  

  Goetliite 
  

  

  10 
  

  

  96-28 
  

  

  

  

  2-42 
  

  

  107 
  

  

  4-32 
  

  

  Goethite 
  

  

  13 
  

  

  91-38 
  

  

  2-79 
  

  

  1-42 
  

  

  1-58 
  

  

  2-37 
  

  

  4-34 
  

  

  Limonite 
  

  

  14 
  

  

  92-88 
  

  

  1-44 
  

  

  0-40 
  

  

  2-75 
  

  

  2-75 
  

  

  4-36 
  

  

  Limonite 
  

  

  15 
  

  

  89-76 
  

  

  3-37 
  

  

  0-99 
  

  

  1-82 
  

  

  2-81 
  

  

  4-35 
  

  

  Limonite 
  

  

  17 
  

  

  90-25 
  

  

  2-42 
  

  

  0-61 
  

  

  2-26 
  

  

  3-60 
  

  

  4-34 
  

  

  Limonite 
  

  

  11 
  

  

  95-44 
  

  

  2-37 
  

  

  

  0-91 
  

  

  1-38 
  

  

  4-07 
  

  

  Lepidocrocite 
  

  

  12 
  

  

  91-96 
  

  

  2-91 
  

  

  1-38 
  

  

  0-92 
  

  

  2-25 
  

  

  412 
  

  

  Lepidocrocite 
  

  

  