﻿Oxides 
  and 
  Sidphides 
  of 
  Iron, 
  etc. 
  67 
  

  

  Heat 
  effect 
  _. 
  12625 
  11329 
  c 
  

  

  " 
  " 
  of 
  sulphur 
  _ 
  12282 
  10978 
  

  

  " 
  " 
  "iron 
  ._ 
  30 
  40 
  

  

  " 
  " 
  " 
  cadmium 
  oxide 
  (b) 
  313 
  311 
  

  

  " 
  " 
  1 
  gram 
  CdO— 
  53 
  49 
  

  

  While 
  the 
  results 
  agree 
  well 
  they 
  are 
  to 
  be 
  regarded 
  as 
  

   approximations 
  since 
  the 
  heat 
  effect 
  of 
  the 
  cadmium 
  oxide 
  is 
  

   only 
  2*5 
  per 
  cent 
  of 
  the 
  total 
  effect 
  of 
  the 
  combustion. 
  The 
  

   mean 
  is 
  51 
  c 
  and 
  for 
  one 
  gram 
  molecule 
  of 
  cadmium 
  oxide 
  it 
  is 
  

   51 
  X 
  128-4 
  = 
  6548 
  c 
  . 
  

  

  Meunier* 
  observed 
  that 
  cadmium 
  oxide 
  dissolved 
  in 
  molten 
  

   sodium 
  hydroxide, 
  but 
  failed 
  to 
  isolate 
  the 
  compound 
  formed. 
  

   The 
  writer 
  has 
  found 
  that 
  the 
  oxide 
  did 
  not 
  dissolve 
  if 
  the 
  

   hydroxide 
  is 
  first 
  heated 
  until 
  free 
  from 
  water. 
  When, 
  how- 
  

   ever, 
  a 
  little 
  water 
  is 
  added 
  to 
  the 
  sodium 
  hydroxide 
  it 
  dis- 
  

   solved 
  cadmium 
  oxide 
  on 
  heating. 
  The 
  fused 
  mass 
  was 
  

   white. 
  When 
  treated 
  with 
  a 
  very 
  small 
  quantity 
  of 
  water 
  and 
  

   filtered, 
  the 
  filtrate 
  on 
  dilution 
  yielded 
  a 
  very 
  little 
  cadmium 
  

   hydroxide. 
  The 
  fusions 
  in 
  the 
  bomb 
  were 
  yellow 
  and 
  for 
  

   reasons 
  already 
  stated 
  the 
  color 
  is 
  not 
  due 
  to 
  cadmium 
  sulphide. 
  

   The 
  difference 
  in 
  the 
  condition 
  of 
  the 
  two 
  kinds 
  of 
  fusion 
  may 
  

   account 
  for 
  the 
  difference 
  in 
  color. 
  In 
  the 
  first 
  case 
  the 
  reac- 
  

   tion 
  is 
  with 
  molten 
  hydrated 
  sodium 
  hydroxide 
  ; 
  in 
  the 
  second 
  

   with 
  sodium 
  oxide 
  at 
  a 
  high 
  temperature. 
  The 
  writer 
  found 
  

   when 
  a 
  mixture 
  of 
  sodium 
  peroxide 
  and 
  cadmium 
  oxide 
  was 
  

   heated 
  that 
  oxygen 
  came 
  off 
  freely 
  and 
  that 
  the 
  sintered 
  mass 
  

   left 
  in 
  water 
  only 
  reddish 
  oxide 
  and 
  no 
  white 
  cadmium 
  

   hydroxide. 
  Evidently 
  the 
  temperature 
  was 
  not 
  sufficient 
  to 
  

   effect 
  combination 
  of 
  the 
  two 
  oxides. 
  

  

  Cadmium 
  Sulphide. 
  — 
  Cadmium 
  sulphide, 
  precipitated 
  by 
  

   hydrogen 
  sulphide 
  from 
  a 
  hot 
  solution 
  of 
  the 
  sulphate, 
  after 
  

   washing 
  and 
  drying 
  was 
  heated 
  to 
  redness 
  in 
  a 
  current 
  of 
  dry 
  

   hydrogen 
  sulphide 
  and 
  then 
  left 
  to 
  cool 
  in 
  the 
  gas. 
  After 
  pul- 
  

   verizing 
  it 
  was 
  heated 
  again 
  as 
  before. 
  Cadmium 
  found, 
  

   77*74 
  per 
  cent 
  : 
  CdS 
  has 
  77*80 
  per 
  cent. 
  Under 
  the 
  micro- 
  

   scope 
  it 
  appeared 
  as 
  an 
  amorphous 
  powder 
  containing 
  a 
  very 
  

   few 
  minute 
  crystals. 
  The 
  following 
  are 
  the 
  experimental 
  

   data 
  : 
  

  

  Cadmium 
  sulphide 
  5*470 
  5*209 
  5*220 
  grams 
  

  

  Sulphur 
  0*0 
  0*500 
  0*500 
  

  

  Sodium 
  peroxide 
  12*7 
  20* 
  20* 
  

  

  Water 
  equivalent 
  of 
  system... 
  3942 
  3988 
  3984 
  

  

  Temperature 
  interval 
  1*715 
  2*291 
  2*283 
  r 
  

  

  *C. 
  R., 
  lxiii, 
  330. 
  

  

  ,o 
  

  

  