﻿Special 
  Case 
  of 
  Gaseous 
  Conduction. 
  

  

  921 
  

  

  in 
  four 
  specially 
  careful 
  and 
  concordant 
  series 
  of 
  measure- 
  

   ments, 
  two 
  in 
  air 
  and 
  two 
  in 
  hydrogen. 
  The 
  second 
  column 
  

   gives 
  the 
  observed 
  values 
  of 
  i/1, 
  the 
  third 
  those 
  calculated 
  

   from 
  (15), 
  putting 
  X 
  = 
  0*0248, 
  corresponding 
  to 
  16°, 
  the 
  

   mean 
  temperature 
  of 
  the 
  experiments. 
  

  

  Table 
  VIII. 
  

  

  V. 
  

  

  ■ill. 
  

  

  *-$• 
  

  

  40 
  

  

  1-000 
  

  

  0-999 
  

  

  16 
  

  

  0996 
  

  

  0-997 
  

  

  12 
  

  

  0-994 
  

  

  0-996 
  

  

  8 
  

  

  991 
  

  

  0994 
  

  

  4 
  

  

  0-987 
  

  

  0-988 
  

  

  2 
  

  

  0-976 
  

  

  975 
  

  

  1 
  

  

  0-949 
  

  

  0-950 
  

  

  0-6 
  

  

  911 
  

  

  0-917 
  

  

  0-4 
  

  

  0-867 
  

  

  0-876 
  

  

  02 
  

  

  0-738 
  

  

  0-752 
  

  

  01 
  

  

  0-508 
  

  

  504 
  

  

  10. 
  We 
  must 
  now 
  inquire 
  whether 
  the 
  necessary 
  condi- 
  

   tions 
  (A) 
  and 
  (B) 
  for 
  the 
  applicability 
  of 
  (15) 
  are 
  in 
  fact 
  

   fulfilled, 
  for 
  if 
  they 
  are 
  not, 
  any 
  agreement 
  between 
  the 
  

   figures 
  in 
  the 
  second 
  and 
  third 
  columns 
  of 
  Table 
  VIII. 
  can 
  

   only 
  be 
  accidental. 
  The 
  results 
  of 
  the 
  inquiry 
  are 
  summarized 
  

   in 
  Table 
  IX. 
  The 
  conditions 
  are 
  least 
  likely 
  to 
  be 
  fulfilled 
  

   in 
  the 
  case 
  of 
  each 
  of 
  the 
  Tables 
  I. 
  -VI. 
  for 
  the 
  greatest 
  value 
  

   of 
  p 
  within 
  the 
  range 
  and 
  the 
  smallest 
  value 
  of 
  V. 
  The 
  

   magnitude 
  of 
  the 
  quantities 
  which 
  have 
  to 
  be 
  small 
  compared 
  

   with 
  1 
  can 
  be 
  calculated 
  by 
  means 
  of 
  the 
  figures 
  given 
  already 
  

   and 
  the 
  known 
  values 
  of 
  oc 
  and 
  D. 
  (These 
  last 
  values 
  have 
  

   been 
  taken 
  from 
  Kaye 
  & 
  Laby's 
  Tables.) 
  The 
  results 
  of 
  the 
  

   calculation 
  applied 
  to 
  the 
  extreme 
  cases 
  of 
  each 
  of 
  the 
  Tables 
  

   are 
  tabulated 
  in 
  columns 
  A 
  and 
  B, 
  corresponding 
  to 
  con- 
  

   ditions 
  (A) 
  and 
  (B). 
  In 
  order 
  to 
  show 
  once 
  more 
  how 
  

   completely 
  the 
  measurements 
  fail 
  to 
  conform 
  to 
  the 
  older 
  

   theory 
  of 
  conduction, 
  the 
  calculated 
  values 
  of 
  Y 
  P 
  for 
  the 
  

   greatest 
  pressure 
  within 
  the 
  range 
  is 
  given 
  in 
  column 
  C. 
  

   An 
  " 
  observed 
  " 
  value 
  for 
  V^, 
  cannot 
  easily 
  be 
  given, 
  for 
  the 
  

   figures 
  in 
  Table 
  VIII. 
  do 
  not 
  fit 
  at 
  all 
  well 
  with 
  the 
  theory 
  

   whatever 
  value 
  of 
  V^ 
  is 
  selected 
  ; 
  but 
  in 
  order 
  to 
  make 
  any 
  

   point 
  fit 
  the 
  theoretical 
  curve, 
  V^ 
  would 
  have 
  to 
  be 
  taken 
  

   >0'1 
  volt. 
  

  

  Since 
  the 
  range 
  of 
  pressures 
  over 
  which 
  the 
  values 
  given 
  

   in 
  Table 
  VIII. 
  are 
  obtained 
  extends 
  further 
  in 
  the 
  direction 
  

  

  