﻿536 
  

  

  Prof. 
  D. 
  N. 
  Mallik 
  on 
  Magnetic 
  

  

  the 
  number 
  of 
  convolutions 
  depending 
  on 
  the 
  strength 
  of 
  the 
  

   field 
  (§8). 
  

  

  I 
  have 
  used 
  the 
  discharge 
  from 
  storage-cells 
  to 
  investigate 
  

   the 
  nature 
  of 
  the 
  curve 
  connecting 
  the 
  potential-difference 
  

   between 
  the 
  electrodes 
  and 
  pressure 
  when 
  the 
  latter 
  is 
  low, 
  

   but 
  as 
  the 
  nature 
  of 
  the 
  discharge 
  changes 
  not 
  merely 
  with 
  

   pressure 
  but 
  also 
  with 
  the 
  current 
  carried 
  by 
  the 
  discharge 
  

   which 
  it 
  is 
  difficult 
  to 
  keep 
  constant, 
  the 
  measurement 
  of 
  

   difference 
  of 
  potential 
  between 
  the 
  electrodes 
  in 
  the 
  case 
  

   of 
  a 
  steady 
  discharge 
  is 
  much 
  more 
  difficult 
  than 
  would 
  

   appear 
  a 
  priori. 
  The 
  following 
  curve 
  (III., 
  fig. 
  8), 
  how- 
  

   ever, 
  fairly 
  represents 
  the 
  main 
  features 
  of 
  the 
  relation 
  

  

  Fii 
  

  

  ■III. 
  

  

  10 
  

  

  

  

  

  

  

  * 
  

  

  

  

  

  

  

  

  

  

  7 
  

  

  

  

  

  1. 
  

  

  

  

  

  

  

  / 
  

  

  

  

  

  

  

  

  

  

  / 
  

  

  

  

  

  & 
  

  

  

  

  

  

  

  / 
  

  

  

  

  

  5 
  

  

  

  

  

  

  

  / 
  

  

  

  

  

  £ 
  h 
  

  

  

  

  

  

  

  

  

  

  

  ^ 
  

  

  

  

  

  

  

  

  

  

  

  !• 
  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  z 
  

  

  

  

  

  

  * 
  \ 
  

  

  

  

  

  

  

  

  100 
  200 
  300 
  400 
  500 
  600 
  700 
  800 
  

  

  Potential 
  o/rr£-/renc£ 
  IN 
  volts 
  Discharge 
  from 
  <50O 
  STORAGE 
  CELLS 
  

   D>sr. 
  bet 
  electrodes 
  S-6 
  cm. 
  

  

  between 
  pressure 
  and 
  difference 
  of 
  potential 
  between 
  the 
  

   electrodes, 
  for 
  a 
  current 
  strength 
  of 
  10 
  milliamperes 
  : 
  the 
  

   difference 
  of 
  potential 
  was 
  read 
  off 
  on 
  an 
  electrostatic 
  

   voltmeter. 
  

  

  18. 
  It 
  is 
  not 
  without 
  interest 
  to 
  compare 
  the 
  character 
  

   of 
  the 
  discharge 
  in 
  this 
  case 
  with 
  that 
  obtained 
  for 
  the 
  same 
  

   distance 
  between 
  the 
  electrodes 
  when 
  an 
  induction-coil 
  is 
  

   used. 
  In 
  the 
  latter 
  case, 
  also, 
  the 
  general 
  character 
  of 
  the 
  

   discharge 
  is 
  of 
  the 
  same 
  form, 
  there 
  being 
  only 
  two 
  stages 
  of 
  

   the 
  discharge 
  " 
  band 
  " 
  and 
  " 
  glow 
  " 
  ; 
  only 
  the 
  range 
  of 
  

   pressure 
  for 
  which 
  the 
  discharge 
  is 
  in 
  the 
  form 
  of 
  a 
  band 
  

   is 
  much 
  greater 
  than 
  with 
  storage-cells, 
  being 
  due 
  to 
  the 
  

   much 
  higher 
  E.M.F. 
  of 
  the 
  induction-coil 
  producing 
  the 
  

   discharge. 
  

  

  