﻿Constituent 
  of 
  the 
  Atmosphere. 
  285 
  

  

  The 
  gas 
  from 
  prepared 
  air 
  was 
  thus 
  in 
  every 
  case 
  denser 
  

   than 
  from 
  unprepared 
  air, 
  and 
  to 
  an 
  extent 
  much 
  beyond 
  the 
  

   possible 
  errors 
  of 
  experiment. 
  The 
  excess 
  was, 
  however, 
  less 
  

   than 
  had 
  been 
  expected, 
  and 
  it 
  was 
  thought 
  that 
  the 
  arrange- 
  

   ment 
  of 
  the 
  pipes 
  could 
  be 
  improved. 
  The 
  final 
  delivery 
  of 
  

   gas 
  from 
  each 
  of 
  the 
  groups 
  in 
  parallel 
  being 
  so 
  small 
  in 
  

   comparison 
  with 
  the 
  whole 
  streams 
  concerned, 
  it 
  seemed 
  pos- 
  

   sible 
  that 
  each 
  group 
  was 
  not 
  contributing 
  its 
  proper 
  share, 
  

   and 
  even 
  that 
  there 
  might 
  be 
  a 
  flow 
  in 
  the 
  wrong 
  direction 
  at 
  

   the 
  delivery 
  end 
  of 
  one 
  or 
  two 
  of 
  them. 
  To 
  meet 
  this 
  objec- 
  

   tion, 
  the 
  arrangement 
  in 
  parallel 
  had 
  to 
  be 
  abandoned, 
  and 
  for 
  

   the 
  remaining 
  experiments 
  eight 
  pipes 
  were 
  connected 
  in 
  simple 
  

   series. 
  The 
  porous 
  surface 
  in 
  operation 
  was 
  thus 
  reduced, 
  but 
  

   this 
  was 
  partly 
  compensated 
  for 
  by 
  an 
  improved 
  vacuum. 
  Two 
  

   experiments 
  were 
  made 
  under 
  the 
  new 
  conditions, 
  in 
  which 
  

   the 
  excess 
  was 
  I, 
  0*0037; 
  II, 
  0-0033. 
  

  

  The 
  excess 
  being 
  larger 
  than 
  before 
  is 
  doubtless 
  due 
  to 
  the 
  

   greater 
  efficiency 
  of 
  the 
  atmolysing 
  apparatus. 
  It 
  should 
  be 
  

   mentioned 
  that 
  the 
  above 
  recorded 
  experiments 
  include 
  all 
  

   that 
  have 
  been 
  tried, 
  and 
  the 
  conclusion 
  seems 
  inevitable 
  that 
  

   " 
  atmospheric 
  nitrogen" 
  is 
  a 
  mixture, 
  and 
  not 
  a 
  simple 
  body. 
  

  

  It 
  was 
  hoped 
  that 
  the 
  concentration 
  of 
  the 
  heavier 
  con- 
  

   stituent 
  would 
  be 
  sufficient 
  to 
  facilitate 
  its 
  preparation 
  in 
  a 
  

   pure 
  state 
  by 
  the 
  use 
  of 
  prepared 
  air 
  in 
  substitution 
  for 
  ordi- 
  

   nary 
  air 
  in 
  the 
  oxygen 
  apparatus. 
  The 
  advance 
  of 
  3-J- 
  milli- 
  

   grams 
  on 
  the 
  11 
  milligrams, 
  by 
  which 
  atmospheric 
  nitrogen 
  is 
  

   heavier 
  than 
  chemical 
  nitrogen, 
  is 
  indeed 
  not 
  to 
  be 
  despised, 
  

   and 
  the 
  use 
  of 
  prepared 
  air 
  would 
  be 
  convenient 
  if 
  the 
  diffu- 
  

   sion 
  apparatus 
  could 
  be 
  set 
  up 
  on 
  a 
  large 
  scale 
  and 
  be 
  made 
  

   thoroughly 
  self-acting. 
  

  

  VII. 
  Negative 
  Experiments 
  to 
  prove 
  that 
  Argon 
  is 
  not 
  derived 
  

   from 
  Nitrogen 
  from, 
  Chemical 
  /Sources. 
  

  

  Although 
  the 
  evidence 
  of 
  the 
  existence 
  of 
  argon 
  in 
  the 
  

   atmosphere, 
  derived 
  from 
  the 
  comparison 
  of 
  densities 
  of 
  atmos- 
  

   pheric 
  and 
  chemical 
  nitrogen 
  and 
  from 
  the 
  diffusion 
  experi- 
  

   ments 
  (§ 
  VI), 
  appeared 
  overwhelming, 
  we 
  have 
  thought 
  it 
  

   undesirable 
  to 
  shrink 
  from 
  any 
  labor 
  that 
  would 
  tend 
  to 
  com- 
  

   plete 
  the 
  verification. 
  With 
  this 
  object 
  in 
  view, 
  an 
  experi- 
  

   ment 
  was 
  undertaken 
  and 
  carried 
  to 
  a 
  conclusion 
  on 
  November 
  

   13, 
  in 
  which 
  3 
  liters 
  of 
  chemical 
  nitrogen, 
  prepared 
  from 
  

   ammonium 
  nitrite, 
  were 
  treated 
  with 
  oxygen 
  in 
  precisely 
  the 
  

   manner 
  in 
  which 
  atmospheric 
  nitrogen 
  had 
  been 
  found 
  to 
  

   yield 
  a 
  residue 
  of 
  argon. 
  The 
  gas 
  remaining 
  at 
  the 
  close 
  of 
  

   the 
  large 
  scale 
  operations 
  was 
  worked 
  up 
  as 
  usual 
  with 
  battery 
  

   and 
  coil 
  until 
  the 
  spectrum 
  showed 
  only 
  slight 
  traces 
  of 
  the 
  

   nitrogen 
  lines. 
  When 
  cold, 
  the 
  residue 
  measured 
  4 
  CC 
  . 
  This 
  

  

  