﻿Mack 
  and 
  Hulett 
  — 
  Water 
  Content 
  of 
  Coal. 
  95 
  

  

  or 
  about 
  two 
  tons 
  per 
  square 
  inch. 
  The 
  amount 
  of 
  beat 
  

   developed 
  in 
  a 
  hundred 
  years 
  in 
  each 
  cubic 
  centimeter 
  of 
  the 
  

   peat 
  substance 
  would 
  have 
  been 
  : 
  

  

  1000 
  (m) 
  X 
  100 
  (cm) 
  X 
  3 
  gm. 
  X 
  0*5 
  meter 
  K 
  ^ 
  . 
  . 
  

  

  . 
  n 
  ' 
  i 
  l 
  ^ 
  . 
  — 
  h 
  o 
  ppuones 
  

  

  4*5 
  (m) 
  X 
  100 
  (cm) 
  X 
  424 
  (mech. 
  equiv. 
  of 
  heat) 
  

  

  If 
  the 
  specific 
  heat 
  of 
  the 
  deposit 
  was 
  '4, 
  the 
  heat 
  produced 
  

   during 
  a 
  hundred 
  years 
  would 
  have 
  been 
  sufficient 
  to 
  raise 
  the 
  

   temperature 
  of 
  the 
  deposit 
  only 
  2°. 
  Even 
  assuming 
  that 
  the 
  

   peat 
  was 
  subjected 
  to 
  a 
  continuous 
  prodigious 
  pressure 
  a 
  

   thousand 
  times 
  as 
  great 
  as 
  that 
  here 
  calculated, 
  still 
  the 
  increase 
  

   in 
  temperature 
  would 
  have 
  been 
  only 
  about 
  2° 
  a 
  month, 
  even 
  

   with 
  perfect 
  insulation 
  : 
  but 
  peat 
  and 
  the 
  adjacent 
  material 
  

   saturated 
  with 
  water 
  are 
  quite 
  good 
  heat 
  conductors. 
  There- 
  

   fore, 
  the 
  heat 
  must 
  have 
  been 
  conducted 
  off 
  almost 
  as 
  fast 
  as 
  

   it 
  was 
  developed 
  and 
  it 
  is 
  difficult 
  to 
  see 
  how 
  the 
  prospective 
  

   coal 
  bed 
  could 
  have 
  been 
  kept 
  above 
  the 
  temperature 
  of 
  the 
  

   surrounding 
  rock 
  strata 
  for 
  any 
  considerable 
  length 
  of 
  time. 
  

   If, 
  however, 
  as 
  a 
  result 
  either 
  of 
  folding 
  or 
  slipping 
  of 
  strata 
  

   (friction), 
  a 
  higher 
  temperature 
  was 
  maintained 
  locally, 
  there 
  

   might 
  have 
  been 
  a 
  sufficient 
  increase 
  in 
  the 
  rate 
  of 
  the 
  chem- 
  

   ical 
  reactions 
  taking 
  place 
  to 
  have 
  caused 
  a 
  comparatively 
  rapid 
  

   alteration 
  of 
  peat- 
  to 
  coal. 
  But 
  this 
  would 
  be 
  local 
  in 
  its 
  

   effects 
  and 
  could 
  be 
  detected. 
  Igneous 
  intrusions 
  do 
  not 
  

   appear 
  to 
  have 
  played 
  any 
  great 
  role. 
  (See 
  The 
  Origin 
  of 
  

   Coal, 
  p. 
  101.) 
  

  

  The 
  foregoing 
  considerations 
  are 
  supported 
  by 
  the 
  experi- 
  

   ments 
  of 
  Dr. 
  F. 
  Bergius,* 
  who 
  actually 
  succeeded 
  in 
  the 
  labora- 
  

   tory 
  in 
  transforming 
  cellulose 
  or 
  peat 
  into 
  a 
  product 
  very 
  much 
  

   resembling, 
  and 
  having 
  the 
  composition 
  of, 
  coal. 
  Hitherto 
  all 
  

   attempts 
  in 
  this 
  direction 
  had 
  failed 
  because, 
  when 
  the 
  peat 
  or 
  

   other 
  raw 
  material 
  was 
  heated 
  in 
  a 
  closed 
  vessel 
  with 
  the 
  

   object 
  of 
  making 
  it 
  into 
  coal, 
  it 
  was 
  found 
  impossible 
  to 
  control 
  

   the 
  temperature 
  of 
  the 
  reacting 
  particles, 
  that 
  is, 
  to 
  avoid 
  a 
  

   superheating 
  of 
  the 
  materials 
  due 
  to 
  the 
  exothermic 
  reactions, 
  

   and 
  for 
  this 
  reason 
  the 
  final 
  products 
  resembled 
  charcoal 
  or 
  

   coke 
  rather 
  than 
  coal, 
  all 
  the 
  volatile 
  and 
  resinous 
  substances 
  

   having 
  been 
  driven, 
  out 
  or 
  decomposed 
  by 
  exposure 
  to 
  too 
  high 
  

   a 
  temperature. 
  In 
  Bergius' 
  experiments 
  this 
  difficulty 
  was 
  

   overcome 
  by 
  heating 
  peat 
  together 
  with 
  a 
  large 
  amount 
  of 
  

   water, 
  where 
  the 
  heat 
  capacity 
  of 
  the 
  liquid 
  water 
  was 
  such 
  

   that 
  it 
  served 
  to 
  absorb 
  the 
  excess 
  heat 
  from 
  the 
  reacting 
  peat 
  

   particles 
  which 
  otherwise 
  would 
  have 
  been 
  superheated. 
  

   Thus 
  the 
  water 
  acted 
  as 
  an 
  excellent 
  thermostat, 
  making 
  it 
  

   possible 
  to 
  control 
  the 
  temperature 
  at 
  which 
  the 
  chemical 
  re- 
  

  

  * 
  Jour. 
  Soc. 
  Chem. 
  Ind., 
  xxxii, 
  p. 
  462, 
  1913. 
  

  

  