﻿886 
  Mr. 
  E. 
  Pcarr 
  Metcalfe 
  

  

  on 
  

  

  Hydkochloeic 
  Acid.— 
  From 
  Strutt's 
  experience 
  of 
  the 
  

   behaviour 
  of 
  this 
  gas 
  in 
  a 
  brass 
  ionization 
  vessel, 
  some 
  

   difficulty 
  was 
  anticipated 
  in 
  dealing 
  with 
  it. 
  When 
  it 
  was 
  

   first 
  run 
  into 
  the 
  vessel 
  the 
  gas 
  was 
  absorbed 
  very 
  rapidly, 
  

   and 
  it 
  was 
  feared 
  that 
  the 
  attempt 
  to 
  work 
  with 
  it 
  must 
  be 
  

   abandoned. 
  As 
  a 
  last 
  resource 
  the 
  generating 
  vessel, 
  in 
  

   which 
  sulphuric 
  acid 
  was 
  being 
  dropped 
  on 
  to 
  ammonium 
  

   chloride, 
  was 
  placed 
  in 
  free 
  communication 
  with 
  the 
  ioniza- 
  

   tion-chamber, 
  and 
  the 
  gas 
  was 
  allowed 
  to 
  remain 
  at 
  rather 
  

   more 
  than 
  atmospheric 
  pressure 
  in 
  contact 
  with 
  the 
  metal 
  

   surfaces 
  tor 
  about 
  eighteen 
  hours. 
  It 
  was 
  found 
  that 
  the 
  

   absorption 
  had 
  then 
  ceased, 
  and 
  reliable 
  readings 
  were 
  

   obtained 
  without 
  difficulty. 
  The 
  metal 
  surfaces 
  had 
  pre- 
  

   sumably 
  become 
  coated 
  with 
  a 
  protecting 
  layer 
  of 
  chloride. 
  

   That 
  the 
  uranium 
  oxide 
  had 
  suffered 
  some 
  change 
  is 
  evident 
  

   from 
  the 
  diminution 
  of 
  the 
  air-constant 
  of 
  the 
  chamber 
  by 
  

   some 
  eight 
  per 
  cent. 
  

  

  Bkomine. 
  — 
  A 
  specimen 
  of 
  the 
  pure 
  liquid 
  was 
  run 
  through 
  

   a 
  tap-funnel 
  into 
  a 
  previously 
  evacuated 
  vessel, 
  in 
  which 
  it 
  

   remained 
  for 
  some 
  hours 
  in 
  contact 
  with 
  pure 
  phosphorus 
  

   pentoxide. 
  From 
  this 
  the 
  vapour 
  was 
  drawn 
  as 
  required 
  

   into 
  the 
  ionization 
  -chamber. 
  The 
  bromine 
  seemed 
  to 
  be 
  

   absorbed 
  very 
  slowly 
  by 
  the 
  metal 
  of 
  the 
  chamber; 
  but 
  after 
  

   a 
  short 
  time 
  it 
  was 
  found 
  possible 
  to 
  maintain 
  a 
  sufficiently 
  

   steady 
  pressure 
  to 
  enable 
  fairly 
  reliable 
  readings 
  to 
  be 
  taken.. 
  

   The 
  error 
  of 
  the 
  determination 
  is 
  probably 
  under 
  two 
  per 
  cent. 
  

  

  The 
  results 
  obtained 
  are 
  given 
  in 
  the 
  following 
  table 
  

   (p. 
  887). 
  

  

  The 
  Additive 
  Ride. 
  

  

  The 
  relation 
  between 
  molecular 
  ionization 
  and 
  chemical 
  

   composition 
  in 
  the 
  case 
  of 
  hydrogen 
  and 
  the 
  first 
  ia.Ye 
  paraffin 
  

   gases 
  is 
  shown 
  graphically 
  in 
  fig. 
  3 
  (p. 
  888) 
  . 
  It 
  will 
  be 
  seen 
  that 
  

   the 
  correspondence 
  between 
  ionization 
  and 
  chemical 
  compo- 
  

   sition 
  is, 
  in 
  the 
  case 
  of 
  this 
  sequence, 
  very 
  close. 
  The 
  fact 
  

   that 
  hydrogen 
  falls 
  into 
  line 
  with 
  the 
  paraffins 
  is 
  somewhat 
  

   remarkable, 
  as 
  hitherto 
  the 
  hydrogen 
  atom 
  has 
  been 
  regarded 
  

   as 
  exceptional 
  in 
  possessing 
  a 
  very 
  different 
  ionization 
  value 
  

   when 
  in 
  combination 
  wdth 
  other 
  atoms 
  to 
  that 
  which 
  it 
  has 
  

   in 
  the 
  molecule 
  II2*. 
  

  

  * 
  Kleeman 
  (Proc. 
  Roy. 
  Soc. 
  A. 
  vol. 
  Ixxix. 
  1907, 
  p. 
  222) 
  gives 
  as 
  the 
  

   " 
  combining" 
  value 
  of 
  the 
  atomic 
  ionization 
  of 
  hydrogen 
  the 
  number 
  

  

  