﻿102 
  Mack 
  and 
  Hulett 
  — 
  Water 
  Content 
  of 
  Coal. 
  

  

  New 
  Eiver 
  Pittsburgh 
  Illinois 
  Wyoming 
  

  

  Per 
  cent 
  gas 
  liberated 
  

  

  at 
  250° 
  

  

  Per 
  cent 
  C0 
  2 
  + 
  CO 
  in 
  

  

  the 
  gas 
  

  

  Per 
  cent 
  gas 
  liberated 
  

  

  at 
  350° 
  

  

  Per 
  cent 
  C0 
  2 
  + 
  CO 
  in 
  

  

  the 
  gas 
  

  

  1-04 
  

   •85 
  

  

  3-16 
  

   •64 
  

  

  At 
  higher 
  temperatures 
  the 
  amounts 
  and 
  rate 
  of 
  formation 
  

   of 
  gas 
  increase 
  rapidly. 
  In 
  addition 
  to 
  the 
  above, 
  " 
  tar 
  " 
  and 
  

   water 
  were 
  volatilized, 
  but 
  they 
  may 
  have 
  been 
  present 
  as 
  

   such 
  in 
  part 
  or 
  largely, 
  and 
  in 
  view 
  of 
  the 
  large 
  percentage 
  of 
  

   C0 
  2 
  and 
  CO 
  in 
  these 
  first 
  gaseous 
  products 
  it 
  may 
  well 
  be 
  that 
  

   they 
  also 
  were 
  largely 
  present 
  as 
  such 
  in 
  the 
  surface 
  film, 
  held 
  

   much 
  as 
  is 
  the 
  water. 
  This 
  would 
  be 
  particularly 
  true 
  of 
  the 
  

   C0 
  2 
  . 
  The 
  moisture 
  contents 
  of 
  these 
  four 
  kinds 
  of 
  coal 
  

   increase, 
  from 
  the 
  New 
  River 
  to 
  Wyoming, 
  in 
  the 
  same 
  ratio 
  

   as 
  do 
  the 
  gas 
  losses 
  at 
  these 
  temperatures. 
  So 
  we 
  may 
  con- 
  

   sider 
  that 
  the 
  adsorption 
  surfaces 
  vary 
  in 
  about 
  the 
  same 
  ratio, 
  

   and 
  it 
  is 
  entirely 
  probable 
  that 
  these 
  first 
  gases 
  were 
  largely 
  

   adsorbed 
  along 
  with 
  the 
  water 
  film. 
  There 
  is 
  no 
  doubt 
  that 
  

   there 
  is 
  some 
  decomposition 
  of 
  coal 
  constituents 
  at 
  250° 
  but 
  it 
  

   is 
  very 
  slow 
  and 
  small 
  in 
  amount 
  for 
  a 
  period 
  of 
  6-7 
  hours, 
  

   while 
  for 
  an 
  hour 
  at 
  this 
  temperature 
  there 
  would 
  be 
  formed 
  

   only 
  a 
  trace 
  of 
  water, 
  but 
  at 
  350° 
  for 
  a 
  comparatively 
  short 
  

   time 
  we 
  would 
  have 
  measurable 
  amounts 
  of 
  water 
  formed 
  by 
  

   decomposition 
  of 
  coal 
  substances. 
  Our 
  work 
  confirms 
  these 
  

  

  