﻿184 
  

  

  Allen 
  and 
  Lombard 
  — 
  Determination 
  of 
  

  

  We 
  have 
  used 
  quartz 
  glass 
  in 
  a 
  number 
  of 
  measurements, 
  and 
  

   have 
  found 
  no 
  special 
  difficulty 
  with 
  it. 
  Doubtless 
  some 
  sul- 
  

   phides 
  like 
  cuprous 
  sulphide 
  do 
  not 
  decompose 
  appreciably 
  

   within 
  this 
  temperature 
  range, 
  and 
  some 
  volatilize 
  unchanged. 
  

   Others 
  like 
  FeS 
  2 
  , 
  CuS, 
  CuFeS 
  2 
  , 
  Cu 
  5 
  FeS 
  4 
  , 
  PtS 
  a 
  and 
  presumably 
  

   those 
  of 
  many 
  other 
  heavy 
  metals 
  dissociate 
  at 
  considerably 
  

   lower 
  temperatures 
  and 
  are 
  within 
  the 
  range 
  of 
  the 
  method. 
  

  

  Fig. 
  5. 
  

  

  600 
  

  

  — 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  G 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  > 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  500 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  -j- 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  >> 
  400 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

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  g 
  300 
  

  

  S 
  

  

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  t 
  

  

  »/ 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  / 
  t 
  

  

  ) 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

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  « 
  

  

  

  

  

  

  

  

  00 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  CD 
  

  

  J* 
  200 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  1 
  

  

  

  

  fU 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

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  ® 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  o 
  

  

  

  

  £± 
  

  

  _u 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  1 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  — 
  

  

  

  

  

  

  

  

  

  

  

  

  400 
  

  

  420 
  440 
  460 
  

  

  Temperature 
  — 
  C°. 
  

  

  480 
  

  

  500 
  

  

  Fig. 
  5. 
  Dissociation 
  pressure 
  curve 
  of 
  covellite 
  (CuS). 
  

  

  H 
  — 
  h 
  Authors' 
  results. 
  

  

  O 
  O 
  Wasjuchnowa's 
  results. 
  

  

  # 
  €H 
  Preunner 
  and 
  Brockmoller 
  s 
  results. 
  

  

  1. 
  Dissociation 
  of 
  covellite 
  ( 
  CuS). 
  

  

  In 
  each 
  particular 
  case 
  where 
  the 
  method 
  is 
  applied, 
  there 
  

   must 
  of 
  course 
  be 
  some 
  means 
  of 
  ascertaining 
  whether 
  the 
  sul- 
  

  

  