﻿Rotation 
  of 
  Electric 
  Discli 
  

  

  uiarae. 
  

  

  545 
  

  

  Fiff. 
  12. 
  

  

  p 
  

  

  Z 
  4 
  fi 
  6 
  10 
  12 
  14- 
  16 
  

  

  where 
  jp 
  is 
  in 
  millimetres 
  of 
  mercury, 
  T 
  in 
  seconds, 
  and 
  m 
  taken 
  

   equal 
  to 
  the 
  length 
  of 
  the 
  rod 
  above 
  the 
  ring. 
  

  

  31. 
  But 
  since 
  we 
  have 
  

   2^ 
  

   Tin 
  

  

  CO 
  

  

  m 
  

  

  fKJ^S 
  

  

  \rHs 
  ' 
  

  

  we 
  nave, 
  corresponamg 
  to 
  any 
  pressure, 
  —^ 
  2 
  , 
  varying 
  as 
  

   roughly 
  or 
  KiKgV 
  very 
  nearly, 
  independent 
  of 
  the 
  

  

  (M 
  

  

  distance 
  between 
  the 
  electrodes. 
  That 
  is, 
  KiK 
  2 
  is 
  practically 
  

   independent 
  of 
  this 
  distance 
  except 
  in 
  so 
  far 
  as 
  V' 
  depends 
  

   on 
  this 
  distance. 
  

  

  32. 
  I 
  have 
  also 
  examined 
  the 
  behaviour 
  of 
  different 
  gases 
  

   and 
  vapours, 
  when 
  the 
  discharge 
  is 
  passed 
  through 
  them 
  at 
  

   different 
  pressures. 
  

  

  In 
  all 
  the 
  following 
  experiments, 
  the 
  distance 
  between 
  the 
  

   electrodes 
  was 
  4*5 
  cm., 
  the 
  number 
  of 
  storage-cells 
  in 
  the 
  

   primary 
  of 
  the 
  induction-coil 
  = 
  3, 
  and 
  the 
  current] 
  in 
  

   the 
  electromagnet 
  circuit 
  3'4 
  amperes. 
  

  

  (For 
  purposes 
  of 
  comparison, 
  the 
  results 
  for 
  air 
  obtained 
  

   with 
  the 
  same 
  apparatus 
  are 
  given 
  below.) 
  

  

  Air. 
  

  

  T 
  

  

  (in 
  seconds). 
  

  

  1-41 
  

  

  1-14 
  

  

  •95 
  

  

  ■86 
  

  

  P 
  

  

  (in 
  millimetres 
  

   of 
  mercury). 
  

   58 
  

   49 
  

   39-4 
  

   34 
  

  

  p 
  

   T" 
  

  

  41-1 
  

   43-3 
  

   41-1 
  

   40 
  

  

  Mean 
  4V35 
  

  

  Phil. 
  Mao. 
  S. 
  6. 
  Vol. 
  1G. 
  No. 
  94. 
  Oct. 
  1908. 
  

  

  2 
  

  

  