﻿Investigation 
  of 
  the 
  Nature 
  of 
  y 
  Hays. 
  

  

  921 
  

  

  a 
  fine 
  specimen, 
  which 
  Dr, 
  Herman 
  Lawrence, 
  of 
  Melbourne, 
  

   was 
  so 
  very 
  kind 
  as 
  to 
  lend 
  us. 
  It 
  was 
  contained, 
  when 
  we 
  

   received 
  it, 
  in 
  a 
  small 
  brass 
  vessel 
  covered 
  with 
  mica, 
  over 
  

   which 
  a 
  little 
  wax 
  had 
  been 
  run. 
  Being 
  very 
  anxious 
  to 
  

  

  Fig. 
  1. 
  

  

  fimecrofi 
  o/) 
  ai 
  

  

  WOMTff: 
  

  

  TO 
  SULPHUR 
  

  

  77fC7f?CM£7S/K. 
  

  

  •TO 
  BATTERY 
  

  

  avoid 
  any 
  trace 
  of 
  emanation 
  escaping 
  into 
  our 
  apparatus, 
  

   and 
  at 
  the 
  same 
  time 
  to 
  run 
  no 
  risk 
  of 
  injuring 
  the 
  specimen, 
  

   w 
  T 
  e 
  covered 
  it 
  still 
  further 
  with 
  asbestos, 
  placed 
  the 
  whole 
  in 
  

   a 
  thin 
  brass 
  vessel, 
  just 
  big 
  enough 
  to 
  hold 
  it, 
  and 
  soldered 
  

   down 
  the 
  lid. 
  Thus 
  the 
  radium 
  was 
  at 
  all 
  times 
  sufficiently 
  

   screened 
  to 
  cut 
  out 
  most 
  of 
  the 
  normal 
  (3 
  rays, 
  and, 
  indeed, 
  

   some 
  of 
  the 
  soft 
  y 
  rays 
  as 
  well. 
  The 
  Dolezalek 
  electrometer 
  

   was 
  fitted 
  with 
  a 
  fine 
  quartz 
  fibre 
  : 
  one 
  volt 
  moved 
  the 
  scale- 
  

   image 
  through 
  four 
  metres. 
  The 
  zero 
  was 
  fairly 
  steady, 
  and 
  

   consecutive 
  readings 
  generally 
  agreed 
  to 
  three 
  per 
  cent. 
  ; 
  the 
  

   differences 
  were 
  by 
  no 
  means 
  wholly 
  due 
  to 
  the 
  electrometer. 
  

   As 
  appears 
  to 
  be 
  usual 
  in 
  the 
  measurement 
  of 
  such 
  small 
  

   currents, 
  we 
  w^ere 
  somewhat 
  troubled 
  by 
  unaccountable 
  

   disturbances, 
  but 
  on 
  most 
  days 
  these 
  were 
  not 
  enough 
  to 
  

   interfere 
  with 
  the 
  general 
  results. 
  

  

  Having 
  set 
  up 
  the 
  apparatus 
  in 
  this 
  way, 
  we 
  proceeded 
  

   first 
  to 
  compare 
  the 
  incidence 
  and 
  emergence 
  radiation 
  of 
  

  

  