﻿422 
  Scientific 
  Intelligence. 
  

  

  At 
  the 
  same 
  meeting, 
  Crookes 
  reported 
  upon 
  the 
  spectrum 
  of 
  

   this 
  gaseous 
  mixture 
  from 
  cleveite, 
  two 
  Plticker 
  tubes 
  containing 
  

   it 
  having 
  been 
  sent 
  to 
  him 
  by 
  Ramsay, 
  the 
  nitrogen 
  in 
  which 
  had 
  

   been 
  previously 
  removed 
  by 
  sparking. 
  By 
  far 
  the 
  most 
  promi- 
  

   nent 
  line 
  was 
  a 
  brilliant 
  yellow 
  one 
  occupying 
  apparently 
  the 
  

   position 
  of 
  the 
  sodium 
  lines. 
  With 
  higher 
  dispersion, 
  however, 
  

   the 
  lines 
  remained 
  single 
  under 
  conditions 
  which 
  would 
  have 
  

   widely 
  separated 
  the 
  lines 
  of 
  sodium. 
  Moreover, 
  on 
  throwing 
  

   sodium 
  light 
  simultaneously 
  into 
  the 
  spectroscope, 
  the 
  spectrum 
  

   of 
  the 
  new 
  gas 
  was 
  seen 
  to 
  consist 
  almost 
  entirely 
  of 
  a 
  bright 
  

   yellow 
  line, 
  a 
  little 
  to 
  the 
  more 
  refrangible 
  side 
  of 
  the 
  sodium 
  

   lines, 
  and 
  separated 
  from 
  them 
  by 
  a 
  space 
  a 
  little 
  more 
  than 
  

   twice 
  that 
  which 
  separated 
  the 
  two 
  components 
  of 
  the 
  sodium 
  

   line. 
  This 
  line 
  appeared 
  as 
  bright 
  and 
  as 
  sharp 
  as 
  D 
  x 
  and 
  D 
  2 
  . 
  

   Careful 
  measurements 
  gave 
  587*45 
  as 
  its 
  wave-length; 
  the 
  wave- 
  

   lengths 
  of 
  the 
  sodium 
  lines 
  being 
  for 
  D 
  l 
  589*51 
  and 
  for 
  D 
  2 
  588*91. 
  

   So 
  that 
  while 
  the 
  difference 
  between 
  the 
  D 
  lines 
  is 
  0'60, 
  that 
  

   between 
  D 
  2 
  and 
  the 
  new 
  line 
  is 
  1*46. 
  It 
  appears, 
  therefore, 
  that 
  

   this 
  line 
  is 
  the 
  spectrum 
  of 
  the 
  hypothetical 
  element 
  helium, 
  dis- 
  

   covered 
  by 
  Lockyer 
  in 
  the 
  chromosphere 
  o 
  of 
  the 
  sun 
  and 
  indicated 
  

   as 
  D 
  3 
  . 
  Its 
  wave-length 
  according 
  to 
  Angstrom 
  is 
  587*49 
  and 
  

   according 
  to 
  Cornu 
  587*46. 
  Besides 
  this 
  line 
  of 
  helium, 
  there 
  

   were 
  seen 
  traces 
  of 
  the 
  more 
  prominent 
  lines 
  of 
  argon. 
  Compar- 
  

   ing 
  the 
  visible 
  spectrum 
  of 
  the 
  new 
  gas 
  with 
  the 
  band 
  and 
  the 
  

   line 
  spectrum 
  of 
  nitrogen, 
  they 
  were 
  found 
  to 
  agree 
  closely 
  at 
  the 
  

   red 
  and 
  the 
  blue 
  ends, 
  and 
  to 
  differ 
  entirely 
  between 
  these 
  points 
  

   through 
  a 
  broad 
  space 
  in 
  the 
  green. 
  The 
  complete 
  spectrum 
  of 
  

   the 
  helium 
  tube 
  is 
  as 
  follows 
  : 
  

  

  

  "Wave 
  -lengths. 
  

  

  

  (a) 
  D 
  3 
  yellow 
  

  

  587*45 
  

  

  Very 
  strong. 
  Sha 
  

  

  (b) 
  Yellowish 
  green 
  

  

  568-05 
  

  

  Faint. 
  ' 
  

  

  (c) 
  

  

  566*41 
  

  

  Very 
  faint. 
  * 
  

  

  (d) 
  Green 
  

  

  516-12 
  

  

  Faint. 
  ' 
  

  

  (e) 
  Greenish 
  blue 
  

  

  500*81 
  

  

  a 
  i 
  

  

  (f) 
  Blue 
  

  

  480-63 
  

  

  l( 
  i 
  

  

  Photographs 
  of 
  this 
  spectrum 
  at 
  first 
  glance 
  show 
  in 
  the 
  violet 
  

   portion, 
  a 
  close 
  resemblance 
  to 
  the 
  band 
  spectrum 
  of 
  nitrogen. 
  

   But 
  a 
  more 
  careful 
  examination 
  shows 
  that 
  some 
  of 
  the 
  bands 
  and 
  

   lines 
  of 
  the 
  nitrogen 
  spectrum 
  are 
  absent 
  from 
  the 
  spectrum 
  of 
  

   the 
  helium 
  tube, 
  while 
  there 
  are 
  many 
  fine 
  lines 
  in 
  the 
  latter 
  

   spectrum 
  which 
  are 
  absent 
  from 
  the 
  spectrum 
  of 
  nitrogen. 
  

   Measurements 
  of 
  these 
  lines 
  are 
  in 
  progress. 
  — 
  Nature, 
  li, 
  512, 
  

   March, 
  1895. 
  Chemical 
  JVeios, 
  lxxi, 
  151, 
  March, 
  1895. 
  g. 
  f. 
  b. 
  

  

  2. 
  On 
  the 
  Combination 
  of 
  Argon 
  tvith 
  Benzene 
  vapor. 
  — 
  By 
  

   means 
  of 
  the 
  silent 
  electric 
  discharge, 
  Berthelot 
  has 
  succeeded 
  

   in 
  effecting 
  the 
  combination 
  of 
  argon 
  with 
  the 
  vapor 
  of 
  benzene. 
  

   The 
  argon 
  was 
  received 
  from 
  Ramsay 
  and 
  had 
  been 
  circulated 
  in 
  

   the 
  apparatus 
  for 
  the 
  absorption 
  of 
  nitrogen 
  until 
  the 
  nitrogen 
  

   bands 
  disappeared 
  and 
  there 
  was 
  no 
  further 
  contraction. 
  The 
  

  

  