﻿Constituent 
  of 
  the 
  Atmosphere. 
  293 
  

  

  of 
  1*288, 
  the 
  mean 
  of 
  all 
  previous 
  determinations 
  ; 
  and 
  the 
  

   half 
  wave-length 
  of 
  sound 
  in 
  hydrogen 
  was 
  found 
  to 
  be 
  73'6, 
  

   instead 
  of 
  74*5, 
  the 
  mean 
  of 
  those 
  previously 
  found. 
  The 
  

   ratio 
  of 
  the 
  specific 
  heats 
  of 
  hydrogen 
  found 
  was 
  1*39, 
  instead 
  

   of 
  1402. 
  

  

  There 
  can 
  be 
  no 
  doubt, 
  therefore, 
  that 
  argon 
  gives 
  practi- 
  

   cally 
  the 
  ratio 
  of 
  specific 
  heats, 
  viz 
  : 
  1*66, 
  proper 
  to 
  a 
  gas 
  in 
  

   which 
  all 
  the 
  energy 
  is 
  translational. 
  The 
  only 
  other 
  gas 
  

   which 
  has 
  been 
  found 
  to 
  behave 
  similarly 
  is 
  mercury 
  gas, 
  

   at 
  a 
  high 
  temperature.* 
  

  

  XV. 
  Attempts 
  to 
  induce 
  Chemical 
  Combination. 
  

  

  Many 
  attempts 
  to 
  induce 
  argon 
  to 
  combine 
  will 
  be 
  described 
  

   in 
  full 
  in 
  the 
  complete 
  paper. 
  Suffice 
  it 
  to 
  say 
  here, 
  that 
  all 
  

   such 
  attempts 
  have 
  as 
  yet 
  proved 
  abortive. 
  Argon 
  does 
  not 
  

   combine 
  with 
  oxygen 
  in 
  presence 
  of 
  alkali 
  under 
  the 
  influence 
  

   of 
  the 
  electric 
  discharge, 
  nor 
  with 
  hydrogen 
  in 
  presence 
  of 
  

   acid 
  or 
  alkali 
  also 
  when 
  sparked 
  ; 
  nor 
  with 
  chlorine, 
  dry 
  or 
  

   moist, 
  when 
  sparked 
  ; 
  nor 
  with 
  phosphorus 
  at 
  a 
  bright-red 
  

   heat, 
  nor 
  with 
  sulphur 
  at 
  bright 
  redness. 
  Tellurium 
  may 
  be 
  

   distilled 
  in 
  a 
  current 
  of 
  the 
  gas 
  ; 
  so 
  may 
  sodium 
  and 
  potassium, 
  

   their 
  metallic 
  luster 
  remaining 
  unchanged. 
  It 
  is 
  unabsorbed 
  

   by 
  passing 
  it 
  over 
  fused 
  red-hot 
  caustic 
  soda, 
  or 
  soda-lime 
  

   heated 
  to 
  bright 
  redness 
  ; 
  it 
  passes 
  unaffected 
  over 
  fused 
  and 
  

   bright 
  red-hot 
  potassium 
  nitrate 
  ; 
  and 
  red-hot 
  sodium 
  peroxide 
  

   does 
  not 
  combine 
  with 
  it. 
  Persulphides 
  of 
  sodium 
  and 
  cal- 
  

   cium 
  are 
  also 
  without 
  action 
  at 
  a 
  red 
  heat. 
  Platinum 
  black 
  

   does 
  not 
  absorb 
  it, 
  nor 
  does 
  platinum 
  sponge, 
  and 
  wet 
  oxidiz- 
  

   ing 
  and 
  chlorinating 
  agents, 
  such 
  as 
  nitro-hydrochloric 
  acid, 
  

   bromine 
  water, 
  bromine 
  and 
  alkali, 
  and 
  hydrochloric 
  acid 
  and 
  

   potassium 
  permanganate, 
  are 
  entirely 
  without 
  action. 
  Experi- 
  

   ments 
  with 
  fluorine 
  are 
  in 
  contemplation, 
  but 
  the 
  difficulty 
  is 
  

   great 
  ; 
  and 
  an 
  attempt 
  will 
  be 
  made 
  to 
  produce 
  a 
  carbon 
  arc 
  

   in 
  the 
  gas. 
  Mixtures 
  of 
  sodium 
  and 
  silica 
  and 
  of 
  sodium 
  and 
  

   boracic 
  anhydride 
  are 
  also 
  without 
  action, 
  hence 
  it 
  appears 
  to 
  

   resist 
  attack 
  by 
  nascent 
  silicon 
  and 
  by 
  nascent 
  boron. 
  

  

  XVI. 
  General 
  Conclusions. 
  

  

  It 
  remains, 
  finally, 
  to 
  discuss 
  the 
  probable 
  nature 
  of 
  the 
  gas, 
  

   or 
  mixture 
  of 
  gases, 
  which 
  we 
  have 
  succeeded 
  in 
  separating 
  

   from 
  atmospheric 
  air, 
  and 
  which 
  we 
  provisionally 
  name 
  argon. 
  

  

  The 
  presence 
  of 
  argon 
  in 
  the 
  atmosphere 
  is 
  proved 
  by 
  many 
  

   lines 
  of 
  evidence. 
  The 
  high 
  density 
  of 
  " 
  atmospheric 
  nitro- 
  

   gen," 
  the 
  lower 
  density 
  of 
  nitrogen 
  from 
  chemical 
  sources, 
  

  

  * 
  Kundt 
  and 
  Warburg, 
  Pogg. 
  Ann. 
  vol. 
  cxxxv, 
  pp. 
  337 
  and 
  527. 
  

  

  