﻿J. 
  J. 
  Stevenson 
  — 
  Origin 
  of 
  Fornikohle. 
  213 
  

  

  often 
  has 
  marked 
  resemblance 
  to 
  pyropissite 
  ; 
  no 
  sharp 
  line 
  of 
  

   separation 
  exists. 
  Schwelkohle 
  is 
  the 
  technical 
  term 
  for 
  pyro- 
  

   pissite-brown 
  coal, 
  which 
  is 
  utilized 
  now 
  in 
  manufacture 
  of 
  

   oils 
  and 
  paraffin, 
  since 
  the 
  purer 
  material 
  is 
  almost 
  exhausted. 
  

   Potonie 
  cites 
  v. 
  Fritsch, 
  who 
  regarded 
  coals 
  as 
  allochthonous, 
  

   to 
  the 
  effect 
  that 
  the 
  flora, 
  providing 
  substance 
  for 
  the 
  brown 
  

   coals, 
  was 
  very 
  rich 
  in 
  resins 
  ; 
  and 
  he 
  looks 
  upon 
  pyropissite 
  as 
  

   consisting 
  essentially 
  of 
  resinous 
  matter. 
  " 
  Necessarily, 
  the 
  

   light 
  resin 
  would 
  float 
  and 
  would 
  be 
  set 
  off 
  in 
  special 
  layers, 
  

   while 
  the 
  somewhat 
  heavier 
  vegetable 
  coal, 
  brown 
  coal 
  proper, 
  

   was 
  forming 
  its 
  layers." 
  He 
  gives 
  the 
  gravity 
  of 
  brown 
  coal 
  

   as 
  1*2 
  to 
  l"4r, 
  and 
  that 
  of 
  pyropissite 
  as 
  9 
  or, 
  when 
  pure, 
  even 
  

   less. 
  

  

  The 
  features 
  observed 
  near 
  Halle 
  in 
  Sachsen 
  agree, 
  in 
  

   Potonie' 
  s 
  opinion, 
  wholly 
  with 
  his 
  conception 
  of 
  origin. 
  Some 
  

   of 
  the 
  coal 
  is 
  clearly 
  autochthonous, 
  but 
  in 
  chief 
  part 
  it 
  is 
  

   secondarily-allochthonous. 
  Between 
  Weissenfels 
  and 
  Alten- 
  

   burg, 
  autochthonous 
  coal 
  is 
  mostly 
  in 
  the 
  southeastern 
  part 
  of 
  

   the 
  area 
  and 
  the 
  other 
  type 
  is 
  in 
  the 
  northwestern 
  part, 
  where 
  

   pyropissite 
  especially 
  abounds 
  — 
  a 
  fact, 
  which 
  suggests 
  that 
  the 
  

   transportation 
  was 
  from 
  southeast 
  to 
  northwest 
  ; 
  but 
  he 
  feels 
  

   that 
  closer 
  investigation 
  must 
  be 
  made 
  before 
  the 
  areas 
  can 
  be 
  

   delimited 
  definitively. 
  It 
  is 
  certain 
  that 
  many 
  mines 
  have 
  

   autochthonous 
  coal 
  in 
  the 
  Liegende 
  and 
  allochthonous 
  in 
  the 
  

   Hangende 
  ; 
  also 
  that, 
  at 
  times, 
  both 
  kinds 
  appear 
  together, 
  as 
  

   in 
  the 
  deep 
  works 
  at 
  Preussengrube, 
  which 
  shows 
  that 
  the 
  

   transporting 
  stream, 
  as 
  in 
  the 
  district 
  west 
  from 
  Coin, 
  had 
  

   afterwards 
  tilled 
  with 
  coal 
  its 
  channel 
  way 
  through 
  the 
  coal 
  

   bed. 
  

  

  The 
  autochthonous 
  coal 
  of 
  the 
  region 
  is 
  characterized 
  macro- 
  

   scopically 
  by 
  numerous 
  irregularly 
  mingled 
  larger 
  and 
  smaller 
  

   pieces 
  of 
  resin 
  (retinite) 
  or 
  by 
  well-distributed 
  pulverized 
  

   resin. 
  This 
  contradicts 
  the 
  opinion 
  that 
  all 
  the 
  coals 
  of 
  this 
  

   region 
  have 
  undergone 
  a 
  separation 
  of 
  the 
  humic 
  and 
  resinous 
  

   constituents, 
  while 
  it 
  makes 
  clear 
  that 
  the 
  brown 
  coals 
  are 
  

   from 
  a 
  flora 
  rich 
  in 
  resins. 
  These 
  autochthonous 
  coals 
  were 
  

   attacked, 
  in 
  part, 
  by 
  the 
  waters; 
  in 
  going 
  northwestwardly 
  

   through 
  the 
  region, 
  one 
  finds 
  more 
  and 
  more 
  abundant 
  that 
  

   type 
  of 
  brown 
  coal 
  which 
  shows 
  by 
  the 
  finely 
  broken 
  material 
  

   that 
  it 
  has 
  been 
  transported. 
  During 
  that 
  transport, 
  there 
  

   occurred 
  through 
  gravity 
  a 
  separation 
  of 
  the 
  constituents 
  ; 
  

   pyropissite 
  increases 
  toward 
  the 
  northwest, 
  where 
  also 
  Piesel- 
  

   kohle 
  and 
  pyropissite-brown 
  coal 
  prevail. 
  

  

  More 
  or 
  less 
  of 
  pyropissite, 
  in 
  layers 
  or 
  smuts, 
  can 
  occur 
  in 
  

   autochthonous 
  coal 
  ; 
  on 
  drier 
  portions 
  decay 
  would 
  take 
  place 
  

   and 
  there 
  would 
  be 
  corresponding 
  enrichment 
  in 
  resinous 
  

   materials, 
  just 
  as 
  one 
  recognizes 
  a 
  corresponding 
  similar 
  enrich- 
  

  

  