﻿Relation 
  between 
  Uranium 
  and 
  Radium. 
  847 
  

  

  they 
  had 
  previously 
  been 
  connected, 
  and 
  transferred 
  to 
  large 
  

   flasks, 
  as 
  shown 
  at 
  A, 
  fig. 
  1. 
  

  

  Fig.l 
  

  

  In 
  the 
  new 
  method 
  of 
  testmg 
  the 
  principle 
  is 
  the 
  same 
  as 
  

   was 
  first 
  employed 
  by 
  Boltwood. 
  After 
  each 
  measurement 
  

   the 
  flask 
  A 
  is 
  sealed 
  at 
  B 
  and 
  C, 
  after 
  being 
  exhausted 
  

   through 
  C, 
  and 
  is 
  left 
  for 
  at 
  least 
  a 
  month 
  for 
  the 
  equilibrium 
  

   amount 
  of 
  emanation 
  to 
  accumulate. 
  The 
  apparatus 
  as 
  shown 
  

   in 
  fig. 
  1 
  does 
  not 
  need 
  detailed 
  description. 
  Before 
  the 
  

   measurement 
  it 
  is 
  exhausted 
  through 
  D, 
  and 
  then 
  water 
  in 
  

   the 
  flask 
  E 
  is 
  admitted 
  through 
  F, 
  by 
  opening 
  the 
  clamp^ 
  

   This 
  is 
  repeated 
  several 
  times 
  to 
  remove 
  any 
  emanation 
  in 
  

   the 
  water. 
  The 
  flask 
  A 
  is 
  heated 
  gradually 
  by 
  steam 
  on 
  the 
  

   water-bath 
  for 
  a 
  short 
  time 
  before 
  the 
  seal 
  is 
  broken 
  to 
  avoid 
  

   percussive 
  boiling. 
  Yiolent 
  irregular 
  boiling 
  is 
  necessary 
  

   thoroughly 
  to 
  agitate 
  the 
  liquid 
  and 
  to 
  remove 
  the 
  emanation. 
  

   If 
  the 
  flask 
  is 
  immersed 
  in 
  warm 
  water 
  boiling 
  tends 
  to 
  be 
  

   confined 
  to 
  the 
  upper 
  layer, 
  and 
  the 
  extraction 
  of 
  emanation 
  

   is 
  imperfect. 
  The 
  seals 
  of 
  the 
  flask 
  are 
  broken 
  under 
  thick 
  

   rubber 
  tubing, 
  a 
  little 
  fresh 
  air 
  being 
  allowed 
  to 
  enter 
  occa- 
  

   sionally 
  as 
  required 
  through 
  the 
  thermometer-tube 
  K. 
  After 
  

   half 
  an 
  hour 
  of 
  vigorous 
  boiling, 
  the 
  clamp 
  C 
  is 
  closed 
  and 
  

   F 
  opened, 
  admitting 
  water 
  until 
  all 
  but 
  a 
  small 
  definite 
  volume 
  

   of 
  Gr 
  is 
  filled. 
  H 
  is 
  then 
  disconnected, 
  and 
  some 
  air 
  thus 
  

   allowed 
  to 
  enter, 
  removing 
  nitric 
  oxide 
  if 
  present. 
  The 
  tube 
  

   F 
  is 
  then 
  connected 
  to 
  G 
  at 
  H, 
  and 
  the 
  arrangement 
  is 
  ready 
  

   for 
  the 
  transference 
  of 
  the 
  emanation 
  into 
  the 
  electroscope. 
  

   The 
  latter 
  is 
  shown 
  in 
  fig. 
  2 
  (p. 
  848). 
  It 
  consists 
  of 
  a 
  glass 
  

  

  