﻿816 
  Prof. 
  E. 
  Rutherford 
  and 
  Mr. 
  T. 
  Royds 
  on 
  the 
  

  

  mercury 
  seal, 
  to 
  prevent 
  any 
  possible 
  leakage 
  of 
  air 
  into 
  the 
  

   bull). 
  At 
  the 
  end 
  of 
  three 
  days, 
  when 
  it 
  was 
  judged 
  that 
  

   the 
  pressure 
  of 
  hydrogen 
  and 
  oxygen 
  formed 
  by 
  the 
  emana- 
  

   tion 
  from 
  the 
  water 
  was 
  about 
  an 
  atmosphere, 
  the 
  bulb 
  was 
  

   again 
  frozen 
  in 
  liquid 
  air 
  and 
  the 
  non-condensable 
  gases 
  

   pumped 
  out 
  and 
  collected. 
  About 
  4 
  c.c. 
  of 
  mixed 
  gases 
  * 
  

   were 
  obtained, 
  consisting 
  mainly 
  of 
  hydrogen 
  and 
  oxygen. 
  

   The 
  gases 
  were 
  then 
  introduced 
  into 
  a 
  separate 
  burette 
  and 
  

   exploded. 
  A 
  small 
  quantity 
  of 
  pure 
  electrolytic 
  oxygen 
  was 
  

   then 
  added, 
  and 
  the 
  gases 
  again 
  exploded 
  to 
  remove 
  any 
  

   excess 
  of 
  hydrogen. 
  The 
  residual 
  gases 
  (about 
  0-2 
  c.c.) 
  were 
  

   not 
  further 
  treated, 
  but 
  passed 
  directly 
  into 
  the 
  receiver 
  E 
  

   in 
  the 
  manner 
  already 
  described, 
  and 
  the 
  gases 
  not 
  absorbed 
  

   by 
  the 
  charcoal 
  were 
  compressed 
  into 
  the 
  vacuum-tube 
  

   and 
  spectroscopically 
  examined. 
  A 
  complete 
  and 
  brilliant 
  

   spectrum 
  of 
  helium 
  was 
  observed, 
  but 
  not 
  a 
  trace 
  of 
  the 
  

   neon 
  spectrum. 
  

  

  The 
  greater 
  part 
  of 
  the 
  emanation 
  had 
  remained 
  condensed 
  

   in 
  the 
  bulb 
  when 
  the 
  mixed 
  gases 
  were 
  pumped 
  out. 
  The 
  

   stopcock 
  was 
  closed 
  and 
  the 
  seal 
  again 
  placed 
  in 
  position 
  and 
  

   the 
  liquid 
  air 
  removed. 
  The 
  bulb 
  was 
  allowed 
  to 
  stand 
  for 
  

   six 
  days, 
  when 
  about 
  4 
  c.c. 
  of 
  the 
  mixed 
  gases 
  were 
  again 
  

   pumped 
  out. 
  As 
  it 
  might 
  be 
  possible 
  that 
  any 
  neon 
  formed 
  

   would 
  be 
  dissolved 
  in 
  the 
  water, 
  the 
  bulb 
  was 
  allowed 
  to 
  

   warm 
  up 
  to 
  atmospheric 
  temperature 
  and 
  then 
  connected 
  

   with 
  the 
  pump. 
  The 
  rapid 
  evaporation 
  of 
  the 
  water 
  then 
  

   gave 
  a 
  chance 
  for 
  removal 
  of 
  any 
  absorbed 
  gases 
  into 
  the 
  

   pump. 
  The 
  small 
  quantity 
  of 
  gas 
  thus 
  obtained 
  was 
  pumped 
  

   out 
  and 
  added 
  to 
  the 
  first 
  quantity. 
  The 
  mixed 
  gases 
  were 
  

   treated 
  as 
  before. 
  A 
  complete 
  spectrum 
  of 
  helium 
  was 
  obtained 
  

   but 
  again 
  no 
  sign 
  of 
  the 
  neon 
  lines. 
  

  

  It 
  might 
  be 
  thought 
  that 
  the 
  presence 
  of 
  the 
  helium 
  in 
  the 
  

   discharge-tube 
  would 
  interfere 
  with 
  the 
  detection 
  of 
  a 
  small 
  

   quantity 
  of 
  neon. 
  A 
  special 
  experiment 
  was 
  made 
  to 
  test 
  

   this 
  point. 
  At 
  the 
  end 
  of 
  the 
  last 
  experiment, 
  the 
  mercury 
  

   was 
  lowered 
  below 
  the 
  level 
  of 
  the 
  carbon 
  tube 
  and 
  y 
  1 
  ^ 
  c.c. 
  

   of 
  air 
  passed 
  into 
  the 
  reservoir. 
  After 
  absorption 
  by 
  the 
  

   charcoal, 
  the 
  residual 
  gases 
  were 
  tested 
  spectroscopically 
  as 
  

   before. 
  The 
  neon 
  spectrum 
  was 
  now 
  clearly 
  seen 
  in 
  addition 
  

   to 
  that 
  of 
  helium. 
  When 
  the 
  lower 
  part 
  of 
  the 
  vacuum-tube 
  

   was 
  cooled 
  to 
  the 
  temperature 
  of 
  liquid 
  air 
  by 
  the 
  pad 
  of 
  

  

  * 
  This 
  amount 
  of 
  mixed 
  gases 
  is 
  one 
  third 
  of 
  that 
  experimented 
  with 
  

   by 
  Cameron 
  and 
  Ramsay, 
  but 
  the 
  amount 
  of 
  neon 
  to 
  be 
  expected 
  from 
  

   their 
  results 
  could 
  have 
  easily 
  been 
  detected 
  with 
  the 
  smaller 
  quantity. 
  

   In 
  experiments 
  recorded 
  later 
  in 
  the 
  paper 
  SO 
  c.c. 
  of 
  mixed 
  gases 
  were 
  

   used. 
  

  

  

  