﻿348 
  Mr. 
  C. 
  Cuthbertson 
  on 
  the 
  Arrangement 
  of 
  

  

  molecule 
  C0 
  2 
  attaches 
  itself 
  to 
  many 
  of 
  the 
  molecules 
  of 
  

   H 
  2 
  0, 
  and 
  forms 
  a 
  big 
  compound 
  molecule. 
  

  

  It 
  has 
  been 
  shown 
  by 
  direct 
  experiments, 
  several 
  years 
  

   ago, 
  that 
  a 
  solution 
  of 
  carbonic 
  acid 
  in 
  water 
  has 
  a 
  greater 
  

   specific 
  gravity 
  than 
  pure 
  water. 
  When, 
  therefore, 
  C0 
  2 
  

   comes 
  into 
  contact 
  with 
  the 
  upper 
  surface 
  of 
  a 
  column 
  of 
  

   water, 
  a 
  liquid 
  is 
  produced 
  which 
  is 
  specifically 
  heavier 
  than 
  

   pure 
  water 
  ; 
  and 
  the 
  heavier 
  liquid 
  sinks, 
  and 
  so 
  a 
  current 
  is 
  

   set 
  up, 
  and 
  in 
  that 
  manner 
  water 
  may 
  become 
  saturated 
  with 
  

   carbonic 
  acid 
  without 
  any 
  shaking 
  up. 
  

  

  Carbonic 
  acid 
  is 
  more 
  than 
  thirty 
  times 
  as 
  soluble 
  as 
  

   oxygen 
  in 
  water 
  ; 
  and 
  the 
  penetration 
  of 
  oxygen 
  into 
  water 
  

   kept 
  at 
  rest 
  must 
  be 
  very 
  much 
  slower 
  than 
  the 
  penetration 
  

   of 
  carbonic 
  acid 
  into 
  water. 
  There 
  can 
  be 
  no 
  doubt 
  that 
  a 
  

   layer 
  of 
  still 
  water 
  of 
  four 
  inches 
  in 
  thickness 
  would 
  protect 
  

   organic 
  matter 
  from 
  the 
  oxidizing 
  action 
  of 
  the 
  oxygen 
  of 
  the 
  

   atmosphere 
  for 
  more 
  than 
  a 
  month 
  — 
  a 
  fact 
  which 
  has 
  an 
  

   important 
  bearing 
  on 
  the 
  sanitary 
  questions 
  of 
  the 
  present 
  

   time. 
  

  

  The 
  Laboratory, 
  New 
  Maiden, 
  Surrey, 
  

   5th 
  February, 
  1902. 
  

  

  XXXVI, 
  Arrangement 
  of 
  Bands 
  in 
  the 
  First 
  Group 
  of 
  

   the 
  Positive 
  Band 
  -Spectrum 
  of 
  Nitrogen. 
  By 
  Olive 
  

   Cuthbertson*. 
  

  

  I 
  SHALL 
  attempt 
  to 
  show 
  that 
  the 
  bands 
  which 
  make 
  

   up 
  the 
  first 
  group 
  (A,= 
  6622 
  to 
  A 
  = 
  5000) 
  in 
  the 
  positive 
  

   band-spectrum 
  of 
  nitrogen 
  can 
  be 
  arranged 
  in 
  series 
  which 
  

   conform 
  to 
  a 
  law 
  similar 
  to 
  that 
  given 
  by 
  Deslandres 
  for 
  the 
  

   second 
  group, 
  which 
  lies 
  between 
  \=5000 
  and 
  \=2820. 
  

  

  The 
  results 
  of 
  Deslandres 
  are 
  published 
  in 
  the 
  Comptes 
  

   Hendus, 
  vols, 
  ciii., 
  civ., 
  and 
  cvi. 
  In 
  the 
  first 
  of 
  these 
  papers 
  

   he 
  states 
  that 
  the 
  bright 
  lines 
  in 
  the 
  band 
  X=391 
  of 
  the 
  

   negative 
  band-spectrum 
  of 
  nitrogen 
  are 
  distributed 
  according 
  

   to 
  the 
  law 
  that 
  a 
  the 
  intervals 
  between 
  one 
  line 
  and 
  the 
  next 
  

   are 
  approximately 
  in 
  arithmetical 
  progression 
  " 
  ; 
  and 
  he 
  adds 
  

   that 
  he 
  has 
  verified 
  this 
  law 
  in 
  the 
  case 
  of 
  several 
  banded 
  

   spectra. 
  In 
  the 
  second 
  paper 
  he 
  announces 
  that 
  the 
  same 
  

   law 
  applies 
  to 
  the 
  frequencies 
  of 
  the 
  heads 
  of 
  the 
  members 
  of 
  

   a 
  group 
  of 
  bands 
  in 
  a 
  certain 
  number 
  of 
  spectra. 
  This 
  was 
  

   first 
  discovered 
  by 
  him 
  in 
  the 
  case 
  of 
  the 
  second 
  group 
  of 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

  

  