﻿52 
  

  

  Mr. 
  W. 
  G. 
  Hormell 
  on 
  the 
  

  

  June 
  20. 
  — 
  100 
  c.c. 
  of 
  the 
  same 
  H 
  2 
  O 
  a 
  solution 
  put 
  in 
  each 
  of 
  two 
  

   flasks, 
  labelled 
  A 
  and 
  B, 
  both 
  being 
  well 
  corked. 
  

   A 
  exposed 
  to 
  available 
  sunshine 
  on 
  June 
  21, 
  22, 
  24, 
  25, 
  27. 
  

   B 
  flask 
  in 
  laboratory. 
  

  

  Analysis 
  of 
  contents 
  showed 
  that 
  H„0 
  o 
  in 
  B 
  : 
  H 
  2 
  2 
  in 
  A 
  

   146 
  : 
  35. 
  

  

  June 
  27. 
  — 
  Fresh 
  lots 
  of 
  solution 
  put 
  in 
  flasks. 
  Sensitive 
  and 
  com- 
  

   pared 
  thermometers 
  in 
  each. 
  

   A 
  kept 
  in 
  the 
  laboratory 
  in 
  the 
  dark 
  in 
  a 
  water-bath 
  at 
  a 
  

   temperature 
  above 
  that 
  of 
  B 
  — 
  which 
  was 
  exposed 
  to 
  available 
  

   sunshine. 
  A 
  always 
  5-2 
  degrees 
  higher 
  than 
  B. 
  B 
  exposed 
  

   to 
  available 
  sunshine 
  June 
  27 
  — 
  July 
  13, 
  when 
  contents 
  

   analysed. 
  

  

  H 
  2 
  2 
  in 
  A 
  : 
  H 
  2 
  2 
  in 
  B 
  = 
  10 
  : 
  1. 
  

  

  In 
  this 
  experiment 
  the 
  average 
  temperature 
  of 
  A 
  was 
  undoubtedly 
  

   higher 
  than 
  B. 
  Moreover, 
  A 
  was 
  subjected 
  to 
  a 
  considerably 
  

   higher 
  temperature 
  (20 
  degrees 
  or 
  so) 
  on 
  two 
  occasions 
  during 
  the 
  

   period 
  than 
  was 
  ever 
  reached 
  by 
  B. 
  

  

  Caius 
  College, 
  Cambridge. 
  

  

  IV. 
  Dielectric 
  Constant 
  of 
  Paraffins. 
  

   By 
  Will 
  G. 
  Hobmell*. 
  

  

  THE 
  following 
  paper 
  presents 
  some 
  experiments 
  in 
  which, 
  

   by 
  means 
  of 
  a 
  modified 
  form 
  of 
  the 
  Blondlot 
  oscillator, 
  

   the 
  dielectric 
  constants 
  of 
  four 
  commercially 
  different 
  paraffins 
  

   were 
  obtained 
  for 
  40-, 
  60-, 
  and 
  80-centimetre 
  waves. 
  The 
  

   paper 
  also 
  contains 
  an 
  investigation 
  of 
  the 
  relative 
  velocities 
  of 
  

   80-centimetre 
  waves 
  along 
  magnetic 
  and 
  non-magnetic 
  wires 
  

   of 
  different 
  diameters. 
  And, 
  finally, 
  there 
  is 
  given 
  in 
  the 
  

   table 
  by 
  way 
  of 
  comparison 
  the 
  light-index 
  of 
  refraction 
  of 
  

   the 
  different 
  paraffins 
  for 
  the 
  Dj 
  line 
  as 
  obtained 
  by 
  means 
  

   of 
  the 
  Abbe 
  Refractometer. 
  

  

  B, 
  

  

  fiouri 
  I. 
  

  

  Ajyparatus. 
  

   ^ 
  Fig. 
  1 
  is 
  a 
  diagram 
  of 
  the 
  connexions 
  made 
  to 
  the 
  various 
  

   pieces 
  of 
  apparatus 
  used 
  in 
  the 
  experiment. 
  The 
  terminals 
  

   * 
  Communicated 
  by 
  Prof. 
  J. 
  Trowbridge. 
  

  

  