﻿544 
  Fntelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  showing 
  no 
  absorption-spectrum, 
  and 
  the 
  meniscus 
  was 
  as 
  well 
  

   denned 
  as 
  in 
  the 
  case 
  of 
  liquid 
  air. 
  The 
  liquid 
  must 
  have 
  a 
  rela- 
  

   tively 
  high 
  refractive 
  index 
  and 
  dispersion, 
  and 
  the 
  density 
  must 
  

   be 
  in 
  excess 
  of 
  the 
  theoretical 
  values, 
  viz. 
  018 
  to 
  0*12, 
  deduced 
  

   respectively 
  from 
  the 
  atomic 
  volume 
  of 
  organic 
  compounds 
  and 
  

   the 
  limiting 
  density 
  found 
  by 
  Amagat 
  for 
  hydrogen 
  gas 
  under 
  

   infinite 
  compression. 
  Professor 
  Dewar's 
  old 
  experiments 
  on 
  the 
  

   density 
  of 
  hydrogen 
  in 
  palladium 
  gave 
  a 
  value 
  for 
  the 
  combined 
  

   body 
  of 
  0-6*2 
  ; 
  and 
  it 
  would 
  be 
  interesting 
  to 
  find 
  the 
  real 
  density 
  

   of 
  the 
  liquid 
  substance 
  at 
  its 
  boiling-point. 
  No 
  arrangements 
  

   being 
  at 
  hand 
  to 
  determine 
  the 
  boiling-point, 
  two 
  experiments 
  

   were 
  made 
  to 
  prove 
  the 
  excessively 
  low 
  temperature 
  of 
  the 
  boiling- 
  

   fluid. 
  In 
  the 
  first 
  place, 
  when 
  a 
  long 
  piece 
  of 
  glass 
  tubing, 
  sealed 
  

   at 
  one 
  end 
  and 
  open 
  to 
  the 
  air 
  at 
  the 
  other, 
  was 
  coaled 
  by 
  im- 
  

   mersing 
  the 
  closed 
  end 
  in 
  the 
  liquid 
  hydrogen, 
  the 
  tube 
  immediately 
  

   filled, 
  where 
  it 
  was 
  cooled, 
  with 
  solid 
  air. 
  The 
  second 
  experiment 
  

   was 
  with 
  a 
  tube 
  containing 
  helium. 
  The 
  Cracow 
  Academy 
  

   • 
  Bulletin 
  ' 
  for 
  1 
  896 
  contained 
  a 
  paper 
  by 
  Professor 
  Olzewski 
  

   entitled 
  " 
  Research 
  on 
  the 
  Liquefaction 
  of 
  Helium," 
  in 
  which 
  he 
  

   stated 
  fhat, 
  as 
  far 
  as 
  his 
  experiments 
  went, 
  helium 
  remained 
  a 
  

   permanent 
  gas, 
  and 
  apparently 
  was 
  much 
  more 
  difficult 
  to 
  liquefy 
  

   than 
  hydrogen. 
  Professor 
  Dewar, 
  however, 
  suggested 
  that 
  hydrogen 
  

   and 
  helium 
  would 
  probably 
  be 
  found 
  to 
  have 
  about 
  the 
  same 
  vola- 
  

   tility, 
  as 
  was 
  the 
  case 
  with 
  oxygen 
  and 
  fluoriue. 
  Having 
  a 
  specimen 
  

   of 
  purified 
  helium, 
  extracted 
  from 
  Bath 
  gas, 
  sealed 
  up 
  in 
  a 
  bulb 
  

   with 
  a 
  narrow 
  tube 
  attached, 
  he 
  placed 
  the 
  latter 
  in 
  the 
  liquid 
  

   hydrogen, 
  whereupon 
  a 
  distinct 
  liquid 
  was 
  seen 
  to 
  condense. 
  From 
  

   this 
  result 
  it 
  would 
  appear 
  that 
  there 
  could 
  not 
  be 
  any 
  great 
  differ- 
  

   ence 
  in 
  the 
  boiling-points 
  of 
  hydrogen 
  and 
  helium. 
  In 
  conclusion, 
  

   Professor 
  Dewar 
  pointed 
  out 
  that 
  all 
  known 
  gases 
  had 
  now 
  been 
  

   condensed 
  into 
  liquids 
  which 
  could 
  be 
  manipulated 
  at 
  their 
  boiling- 
  

   points 
  under 
  atmospheric 
  pressure 
  in 
  suitably 
  arranged 
  \acuum 
  

   vessels, 
  though 
  even 
  so 
  great 
  a 
  man 
  as 
  Clerk- 
  Maxwell 
  had 
  doubts 
  as 
  

   to 
  the 
  possibility 
  of 
  ever 
  liquefying 
  hydrogen. 
  With 
  liquid 
  hydrogen 
  

   as 
  the 
  cooling 
  agent, 
  a 
  temperature 
  could 
  be 
  reached 
  within 
  20° 
  or 
  

   30° 
  of 
  the 
  zero 
  of 
  absolute 
  temperature 
  ; 
  and 
  its 
  use 
  would 
  open 
  

   up 
  an 
  entirely 
  new 
  field 
  of 
  scientific 
  inquiry. 
  No 
  one 
  could 
  pre- 
  

   dict 
  the 
  properties 
  of 
  matter 
  near 
  that 
  zero. 
  Faraday 
  liquefied 
  

   chlorine 
  in 
  the 
  year 
  1823. 
  Sixty 
  years 
  afterwards 
  Wroblewski 
  

   and 
  Olzewski 
  produced 
  liquid 
  air, 
  and 
  now, 
  after 
  an 
  interval 
  of 
  

   fifteen 
  years^ 
  the 
  remaining 
  gases 
  — 
  hydrogen 
  aud 
  helium 
  — 
  were 
  

   obtained 
  as 
  static 
  liquids. 
  Considering 
  the 
  step 
  from 
  the 
  lique- 
  

   faction 
  of 
  air 
  to 
  that 
  of 
  hydrogen 
  was 
  relatively 
  as 
  great 
  in 
  a 
  

   thermodynamic 
  sense 
  as 
  that 
  from 
  liquid 
  chlorine 
  to 
  liquid 
  air, 
  the 
  

   fact 
  that 
  the 
  former 
  had 
  been 
  achieved 
  in 
  one-fourth 
  the 
  time 
  

   needed 
  to 
  accomplish 
  the 
  latter 
  proved 
  the 
  greatly 
  accelerated 
  rate 
  

   of 
  scientific 
  progress 
  in 
  the 
  present 
  age. 
  The 
  paper 
  ended 
  with 
  

   an 
  acknowledgment 
  of 
  the 
  aid 
  rendered 
  by 
  Mr. 
  Robert 
  Lennox, 
  

   without 
  whose 
  engineering 
  skill, 
  manipulative 
  ability, 
  and 
  loyal 
  

   perseverance 
  the 
  present 
  successful 
  issue 
  might 
  have 
  been 
  indefi- 
  

   nitely 
  delayed.— 
  The 
  Times, 
  May 
  13th, 
  1898. 
  

  

  