﻿Uhler 
  and 
  Patterson 
  — 
  Arc 
  Spectrum 
  of 
  Tellurium. 
  139 
  

  

  the 
  wave-lengths 
  of 
  the 
  iron 
  lines, 
  we 
  are 
  of 
  the 
  opinion 
  that 
  

   0*005 
  A 
  is 
  a 
  fair 
  estimate 
  of 
  the 
  possible 
  error 
  of 
  our 
  results 
  

   for 
  lines 
  1 
  to 
  8 
  inclusive. 
  Lines 
  9 
  and 
  10 
  were 
  so 
  faint 
  in 
  the 
  

   second 
  order 
  as 
  to 
  preclude 
  the 
  possibility 
  of 
  measuring 
  them 
  

   closer 
  than 
  O'Ol 
  A. 
  Their 
  wave-leugths 
  were 
  checked 
  up 
  in 
  

   the 
  first 
  order. 
  Line 
  11 
  was 
  also 
  measured 
  in 
  the 
  first 
  order 
  

   of 
  the 
  largest 
  grating, 
  whereas 
  lines 
  12 
  to 
  15 
  could 
  only 
  be 
  

   obtained 
  with 
  2 
  Lumiere 
  plates 
  in 
  the 
  first 
  order 
  of 
  the 
  10 
  ft. 
  

   grating 
  and 
  with 
  Panchromatic 
  films 
  in 
  the 
  same 
  order 
  of 
  the 
  

   meter 
  spectrograph. 
  

  

  As 
  to 
  the 
  arc 
  lines 
  themselves 
  the 
  following 
  remarks 
  may 
  

   not 
  be 
  superfluous. 
  By 
  using 
  some 
  metallic 
  tellurium 
  which 
  

   contained 
  a 
  trace 
  of 
  tin 
  as 
  an 
  impurity 
  an 
  excellent 
  negative 
  

   w 
  T 
  as 
  obtained, 
  in 
  the 
  second 
  order 
  of 
  the 
  largest 
  grating, 
  which 
  

   showed 
  the 
  iron, 
  tin 
  and 
  tellurium 
  lines 
  very 
  sharp 
  and 
  fully 
  

   resolved. 
  The 
  wave-lengths 
  are 
  3175*044, 
  3175-130 
  and 
  

   3175*447 
  for 
  tin, 
  tellurium 
  and 
  iron 
  in 
  the 
  order 
  named. 
  This 
  

   removes 
  all 
  doubt 
  as 
  to 
  the 
  independence 
  of 
  the 
  tin 
  and 
  tellu- 
  

   rium 
  lines. 
  In 
  like 
  manner 
  the 
  antimony 
  and 
  tellurium 
  lines 
  

   at 
  2769*94 
  and 
  2769'653 
  were 
  differentiated. 
  Lines 
  6, 
  7, 
  9, 
  

   and 
  14 
  were 
  broadly 
  and 
  symmetrically 
  reversed, 
  in 
  general, 
  

   and 
  they 
  seem 
  to 
  belong 
  to 
  a 
  class 
  by 
  themselves. 
  Line 
  6 
  was 
  

   always 
  wider 
  and 
  a 
  little 
  more 
  intense 
  than 
  line 
  7. 
  Lines 
  4 
  

   and 
  5 
  were 
  never 
  obtained 
  reversed 
  or 
  double 
  with 
  the 
  two 
  

   larger 
  gratings. 
  Strange 
  to 
  say, 
  when 
  the 
  films 
  were 
  examined 
  

   with 
  a 
  compound 
  microscope 
  each 
  of 
  these 
  lines 
  appeared 
  to 
  

   be 
  double. 
  The 
  duplicity 
  seemed 
  to 
  be 
  due 
  to 
  self-reversal 
  

   because 
  the 
  separation 
  of 
  the 
  components 
  varied 
  from 
  film 
  to 
  

   film. 
  The 
  reversal 
  is 
  asymmetric, 
  but 
  in 
  some 
  cases 
  the 
  longer 
  

   wave-length 
  component 
  is 
  the 
  weaker, 
  and 
  in 
  others 
  just 
  the 
  

   opposite 
  holds. 
  The 
  reversal 
  was 
  wider 
  when 
  a 
  pure 
  salt 
  was 
  

   tamped 
  in 
  the 
  lower 
  electrode 
  than 
  when 
  the 
  metal 
  alone 
  was 
  

   used. 
  Salts 
  were 
  not 
  used 
  with 
  the 
  largest 
  grating. 
  Lines 
  11, 
  

   12, 
  13, 
  and 
  15 
  never 
  appeared 
  reversed 
  on 
  the 
  negatives. 
  All 
  

   the 
  remaining 
  lines 
  were 
  easily 
  obtained 
  with 
  fine, 
  symmetri- 
  

   cal, 
  axial 
  self 
  -absorption. 
  As 
  might 
  be 
  expected, 
  the 
  reversal 
  

   of 
  any 
  one 
  line 
  is 
  widest 
  at 
  the 
  end 
  corresponding 
  to 
  the 
  posi- 
  

   tive, 
  lower 
  electrode. 
  

  

  Because 
  other 
  investigators 
  have 
  been 
  unable 
  to 
  repeat 
  the 
  

   work 
  of 
  Flint 
  in 
  such 
  a 
  manner 
  as 
  to 
  obtain 
  his 
  low 
  value 
  for 
  

   the 
  atomic 
  weight 
  of 
  tellurium, 
  it 
  may 
  not 
  be 
  superfluous 
  to 
  

   state 
  the 
  results 
  of 
  our 
  spectroscopic 
  analysis 
  of 
  the 
  specimens 
  

   which 
  he 
  left 
  with 
  one 
  of 
  us 
  in 
  the 
  spring 
  of 
  1911. 
  The 
  

   white 
  needles 
  which 
  corresponded 
  to 
  the 
  atomic 
  weight 
  127*45, 
  

   when 
  vaporized 
  in 
  the 
  arc, 
  showed 
  only 
  slight 
  traces 
  of 
  anti- 
  

   mony 
  and 
  copper. 
  It 
  must 
  be 
  remembered, 
  however, 
  that 
  

   some 
  elements 
  such 
  as 
  selenium 
  do 
  not 
  give 
  lines 
  in 
  the 
  elec- 
  

  

  Am. 
  Jour 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  XXXV, 
  No. 
  212.— 
  August, 
  1913. 
  

   10 
  

  

  