﻿Hornor 
  — 
  Use 
  of 
  Sealing 
  Wax, 
  etc. 
  591 
  

  

  Art. 
  LI. 
  — 
  On 
  the 
  Use 
  of 
  Sealing 
  Wax 
  as 
  a 
  Source 
  of 
  Lime 
  

   for 
  the 
  Wehnelt 
  Cathode; 
  by 
  Nellie 
  N. 
  Hornor. 
  

  

  In 
  the 
  Wehnelt* 
  cathode 
  as 
  first 
  employed 
  various 
  metallic 
  

   oxides 
  were 
  used 
  as 
  salts. 
  Those 
  of 
  calcium, 
  barium, 
  and 
  

   strontium 
  gave 
  an 
  abnormally 
  large 
  discharge 
  of 
  negative 
  elec- 
  

   tricity. 
  The 
  sign 
  of 
  the 
  electrification 
  depends 
  upon 
  the 
  metal 
  

   used 
  and 
  also 
  upon 
  the 
  class 
  of 
  the 
  salt.f 
  Willows 
  and 
  Ficton^: 
  

   used 
  nickel 
  and 
  platinum 
  strips 
  for 
  the 
  cathode, 
  while 
  Richard- 
  

   son 
  § 
  employed 
  both 
  the 
  tube 
  and 
  strip 
  methods, 
  and 
  recently 
  

   Sheard 
  [ 
  used 
  the 
  tube 
  method. 
  

  

  The 
  conditions 
  affecting 
  the 
  efficiency 
  of 
  this 
  form 
  of 
  cathode 
  

   have 
  also 
  been 
  studied 
  by 
  Horton,T 
  Garrett,** 
  and 
  Wilson. 
  f 
  f 
  

   In 
  the 
  work 
  by 
  Willows 
  and 
  Picton, 
  referred 
  to 
  above, 
  they 
  

   found 
  that 
  when 
  using 
  a 
  pressure 
  of 
  •002 
  mm 
  Hg 
  and 
  up, 
  a 
  volt- 
  

   age 
  of 
  36, 
  and 
  a 
  temperature 
  of 
  1100 
  degrees 
  Centigrade, 
  there 
  

   was 
  a 
  decided 
  increase 
  in 
  the 
  activity 
  of 
  the 
  salt 
  when 
  the 
  

   cathode 
  had 
  stood 
  cold 
  over 
  a 
  period 
  of 
  several 
  days 
  or 
  weeks. 
  

   They 
  also 
  found 
  a 
  greatly 
  increased 
  stream 
  of 
  electrons 
  on 
  

   making 
  the 
  discharge 
  after 
  it 
  had 
  been 
  broken 
  for 
  a 
  time, 
  the 
  

   heating 
  current 
  continued 
  the 
  while. 
  The 
  accumulation 
  of 
  

   electrons 
  in 
  the 
  heated 
  lime 
  was 
  dependent 
  upon 
  the 
  interval 
  

   of 
  time. 
  

  

  It 
  has 
  been 
  known 
  for 
  some 
  time 
  that 
  ordinary 
  sealing 
  wax 
  

   makes 
  a 
  fairly 
  good 
  source 
  of 
  lime. 
  The 
  Bank 
  of 
  England 
  

   wax 
  seems 
  quite 
  satisfactory. 
  Its 
  use, 
  however, 
  was 
  until 
  

   recently 
  confined 
  to 
  the 
  Cavendish 
  laboratory. 
  For 
  some 
  time 
  

   it 
  has 
  been 
  evident 
  that 
  its 
  behavior 
  as 
  a 
  lime 
  is 
  different 
  than 
  

   that 
  of 
  the 
  oxides 
  which 
  are 
  generally 
  used. 
  Hence 
  the 
  fol- 
  

   lowing 
  investigation, 
  in 
  which 
  the 
  object 
  is 
  a 
  study 
  of 
  the 
  

   activity 
  of 
  this 
  source 
  of 
  lime 
  together 
  with 
  the 
  various 
  con- 
  

   ditions 
  best 
  suited 
  for 
  its 
  efficient 
  working. 
  

  

  Description 
  of 
  Apparatus. 
  

  

  A 
  sketch 
  of 
  the 
  apparatus 
  used 
  is 
  shown 
  in 
  fig. 
  1. 
  MJVis 
  a 
  

   two 
  liter 
  spherical 
  flask, 
  S' 
  is 
  a 
  drying 
  bulb, 
  B' 
  the 
  heating 
  

   circuit, 
  the 
  cathode, 
  and 
  A 
  the 
  anode. 
  The 
  aluminium 
  disc 
  

   G-' 
  was 
  connected 
  through 
  a 
  reversing 
  switch 
  K' 
  to 
  the 
  galvano- 
  

  

  *Phil. 
  Mag., 
  vol. 
  x, 
  July, 
  1905. 
  

  

  \ 
  J. 
  J. 
  Thomson, 
  Proc. 
  Camb. 
  Phil. 
  Soc, 
  vol. 
  xiv, 
  1906. 
  

  

  jPhys. 
  Soc, 
  London, 
  Proc, 
  June, 
  1911. 
  

  

  § 
  Phil. 
  Mag., 
  vol. 
  xx, 
  1910. 
  

  

  || 
  Phil. 
  Mag., 
  vol. 
  xxv, 
  March, 
  1913. 
  

  

  II 
  Phil. 
  Trans. 
  Sec 
  A, 
  vol. 
  ccvii, 
  1907. 
  

  

  ** 
  Phil. 
  Mag., 
  vol. 
  xx. 
  October, 
  1910. 
  

  

  ff 
  Phil. 
  Mag., 
  'vol. 
  xxi, 
  May, 
  1911. 
  

  

  