﻿THE 
  

  

  FEB 
  2- 
  iyl/ 
  

  

  '°nai 
  Mus 
  

  

  AMERICAN 
  JOURNAL 
  OF 
  SCIENCE 
  

  

  [FOURTH 
  SERIES.] 
  

  

  Art. 
  X. 
  — 
  The 
  Water 
  Content 
  of 
  Coal, 
  with 
  Some 
  Ideas 
  on 
  

   the 
  Genesis 
  and 
  Nature 
  of 
  Coal 
  ; 
  by 
  Ed 
  ward 
  Mack 
  and 
  

   G. 
  A. 
  Hulett. 
  

  

  Part 
  I. 
  Water 
  Content 
  of 
  Coal 
  in 
  relation 
  to 
  its 
  Origin 
  and 
  

  

  Constitution. 
  

  

  At 
  the 
  present 
  time 
  onr 
  understanding 
  of 
  the 
  nature 
  of 
  

   coal 
  is 
  largely 
  limited 
  to 
  a 
  knowledge 
  of 
  the 
  chemical 
  elements 
  

   present 
  in 
  the 
  coal 
  substance, 
  while 
  there 
  is 
  little 
  known 
  about 
  

   the 
  chemical 
  compounds 
  present, 
  or 
  about 
  the 
  physical 
  prop- 
  

   erties 
  of 
  coal. 
  Since 
  the 
  economic 
  utilization 
  of 
  coal 
  depends 
  

   mainly 
  on 
  destructive 
  distillation, 
  it 
  is 
  of 
  first 
  importance 
  to 
  

   have 
  definite 
  information 
  about 
  the 
  constitution 
  of 
  the 
  various 
  

   kinds 
  of 
  coal, 
  and 
  much 
  attention 
  has 
  been 
  given 
  to 
  this 
  sub- 
  

   ject, 
  especially 
  during 
  the 
  past 
  few 
  years, 
  from 
  the 
  standpoint 
  

   of 
  distillation 
  at 
  low 
  temperatures 
  and 
  pressures 
  and 
  by 
  the 
  

   use 
  of 
  extractive 
  solvents. 
  

  

  Commercially 
  it 
  has 
  been 
  found 
  desirable 
  to 
  know 
  the 
  mois- 
  

   ture 
  content 
  of 
  coals 
  and 
  chemists 
  adopted 
  the 
  usual 
  analytical 
  

   method 
  for 
  moisture, 
  namely, 
  drying 
  the 
  sample 
  in 
  an 
  oven 
  at 
  

   105° 
  C. 
  But 
  it 
  soon 
  developed 
  that 
  the 
  results 
  were 
  not 
  con- 
  

   cordant 
  or 
  reproducible, 
  and 
  for 
  that 
  reason 
  several 
  committees 
  

   have 
  been 
  appointed 
  to 
  look 
  into 
  the 
  question. 
  Among 
  these 
  

   committees 
  was 
  one 
  which 
  reported 
  to 
  the 
  Eighth 
  Interna- 
  

   tional 
  Congress 
  of 
  Applied 
  Chemistry 
  in 
  1912.* 
  At 
  that 
  time 
  

   it 
  was 
  recommended 
  that 
  in 
  making 
  moisture 
  analyses 
  a 
  special 
  

   oven 
  be 
  used 
  which 
  would 
  provide 
  proper 
  temperature 
  control, 
  

   since 
  there 
  is 
  sometimes 
  a 
  variation 
  of 
  15° 
  C, 
  or 
  more, 
  in 
  dif- 
  

  

  * 
  Holloway 
  and 
  Coste, 
  Report 
  of 
  Sub-Committee 
  10 
  of 
  the 
  International 
  

   Commission 
  on 
  Analysis. 
  Also, 
  Hillebrand 
  and 
  Badger, 
  Proc. 
  8th 
  Intern. 
  

   Cong. 
  Appl. 
  Chem., 
  vol. 
  x, 
  187. 
  

  

  Am. 
  Jour. 
  Sci. 
  — 
  Fourth 
  Series, 
  Vol. 
  XLIII, 
  No. 
  254. 
  — 
  February, 
  1917. 
  

  

  7 
  

  

  