﻿31 
  

  

  W. 
  G. 
  Mixler 
  — 
  Calorimetry 
  by 
  Combustions. 
  

  

  the 
  bomb 
  in 
  order 
  to 
  loosen 
  it. 
  The 
  bomb 
  and 
  cup 
  are 
  cleaned 
  

   with 
  strong 
  hydrochloric 
  acid, 
  washed 
  and 
  polished. 
  The 
  top 
  

   is 
  cleaned 
  in 
  the 
  same 
  way 
  but 
  does 
  not 
  require 
  polishing. 
  The 
  

   silver 
  cup 
  is 
  often 
  partly 
  melted 
  'by 
  a 
  sodium-peroxide 
  combus- 
  

   tion 
  and 
  a 
  number 
  should 
  be 
  provided. 
  The 
  top 
  of 
  the 
  cup 
  is 
  

   easily 
  expanded, 
  if 
  desired, 
  by 
  pressing 
  it 
  against 
  the 
  hemis- 
  

   pherical 
  bottom 
  of 
  the 
  bomb. 
  

  

  The 
  following 
  experiments* 
  illustrate 
  the 
  use 
  of 
  the 
  sodium- 
  

   peroxide 
  mixture 
  : 
  

  

  Iron 
  :_ 
  

  

  Sulphur 
  

  

  Sodium 
  peroxide 
  

  

  Water 
  equivalent 
  of 
  

  

  system 
  

  

  Temperature 
  interval 
  

  

  Heat 
  effect 
  

  

  Heat 
  effect 
  of 
  sulphur 
  

  

  " 
  " 
  " 
  ignition 
  

  

  wire 
  

  

  2-550 
  

   1-500 
  

  

  20- 
  

  

  3080 
  

   4-016 
  

  

  12369 
  

   — 
  7905 
  

  

  — 
  80 
  

  

  1-754 
  

   1-500 
  

   19- 
  

  

  3078 
  

   3-573 
  

  

  10998 
  

   - 
  7905 
  

  

  — 
  80 
  

  

  1-754 
  

   1-500 
  

  

  20- 
  

  

  3188 
  

   3-423 
  

  

  10912 
  

   — 
  7905 
  

  

  - 
  60 
  

  

  3-000 
  

   1-500 
  

   22- 
  

  

  4108 
  

   3-180° 
  

  

  13063 
  c 
  

  

  — 
  7860 
  

  

  — 
  45 
  

  

  4384 
  

  

  Heat 
  effect 
  of 
  1 
  grm. 
  

  

  Fe 
  1719 
  

  

  3013 
  

   1718 
  

  

  Ferric 
  oxide 
  5-403 
  

  

  Sulphur 
  1 
  -500 
  

  

  Sodium 
  peroxide 
  20* 
  

  

  Water 
  equivalent 
  of 
  system.. 
  4112 
  

  

  Temperature 
  interval 
  2-378 
  

  

  9778 
  

  

  Heat 
  effect 
  

  

  " 
  of 
  S 
  

  

  " 
  " 
  " 
  Fe 
  wire... 
  

   " 
  " 
  " 
  2 
  set 
  free 
  

   Heat 
  effect 
  of 
  Fe 
  o 
  o 
  

  

  a 
  u 
  

  

  " 
  " 
  1 
  gram 
  of 
  Fe 
  a 
  O, 
  

   Pvrite 
  FeS„ 
  

  

  7860 
  

   — 
  45 
  

   + 
  80 
  

   1953 
  

   361 
  

  

  2947 
  

  

  1680 
  

  

  5-115 
  

  

  1-500 
  

  

  19- 
  

  

  4137 
  

  

  2-352 
  

  

  9730 
  

   — 
  7860 
  

   — 
  45 
  

   + 
  31 
  

   1856 
  

   363 
  

  

  4-011 
  

  

  Sodium 
  peroxide 
  '. 
  24' 
  

  

  5158 
  

  

  1719 
  

  

  5 
  2 
  96 
  grams 
  

   1-500 
  " 
  

   20- 
  

   4149 
  

   2-353° 
  

  

  9762 
  c 
  

   — 
  7860 
  

   — 
  45 
  

   + 
  82 
  

   1939 
  

   366 
  

  

  4-059 
  

   24- 
  

   4085 
  

   3-316 
  

  

  Water 
  equiv. 
  of 
  system 
  _ 
  . 
  4045 
  

  

  Temperature 
  interval 
  . 
  3*301 
  

  

  Heat 
  effect 
  13352 
  13545 
  

  

  " 
  of 
  iron... 
  —40 
  —50 
  

  

  u 
  « 
  " 
  FeS 
  2 
  13312 
  13496 
  

  

  " 
  " 
  " 
  1 
  grm 
  3318 
  3325 
  

  

  The 
  heats 
  of 
  formation 
  of 
  ferric 
  oxide 
  and 
  pyrite 
  may 
  be 
  

   derived 
  from 
  the 
  foregoing 
  results. 
  The 
  different 
  heat 
  effects 
  

   of 
  sulphur 
  given 
  in 
  the 
  tables 
  were 
  found 
  by 
  burning 
  it 
  with 
  

   the 
  two 
  lots 
  of 
  sodium 
  peroxide 
  used. 
  

  

  * 
  This 
  Journal, 
  xxxvi, 
  55, 
  1913. 
  

  

  