﻿of 
  the 
  Atomic 
  Weights 
  of 
  Elementary 
  Substances. 
  739 
  

  

  The 
  positions 
  o£ 
  helium 
  and 
  neon 
  in 
  my 
  general 
  Table 
  of 
  

   Elements, 
  as 
  the 
  transformation 
  ultimates 
  of 
  the 
  series 
  H2?i 
  

   and 
  H7?i 
  respectively, 
  are 
  further 
  interesting 
  in 
  connexion 
  

   with 
  the 
  recent 
  announcements 
  that 
  these 
  elements 
  have 
  

   been 
  found 
  in 
  glass 
  vessels 
  in 
  which 
  they 
  had 
  no 
  previous 
  

   existence*. 
  Now, 
  assuming 
  the 
  reality 
  of 
  these 
  observations, 
  

   the 
  phenomena 
  not 
  only 
  admit 
  of 
  explication 
  from 
  my 
  classi- 
  

   fication 
  of 
  the 
  elements, 
  but 
  also 
  account 
  for 
  the 
  discordant 
  

   results 
  obtained 
  by 
  the 
  experimenters 
  engaged 
  in 
  the 
  

   research. 
  

  

  Several 
  significant 
  facts 
  were 
  brought 
  out 
  by 
  the 
  investi- 
  

   gators 
  during 
  their 
  researches, 
  viz.: 
  — 
  the 
  use 
  of 
  old 
  X-ray 
  

   tubes, 
  bare 
  glass 
  tubes, 
  and 
  glass 
  wool, 
  from 
  all 
  which 
  neon 
  

   and 
  helium 
  were 
  obtained. 
  One 
  of 
  the 
  investigators 
  could 
  

   onlv 
  find 
  neon 
  as 
  a 
  transformation 
  product, 
  while 
  others, 
  

   working 
  independently, 
  found 
  helium 
  alone, 
  and 
  in 
  other 
  

   cases 
  a 
  mixture 
  of 
  both 
  gases. 
  

  

  These 
  results 
  were 
  of 
  sufficient 
  interest 
  to 
  induce 
  me 
  to 
  

   ascertain 
  the 
  composition 
  of 
  various 
  glasses 
  used 
  in 
  the 
  arts, 
  

   from 
  which 
  the 
  following 
  are 
  selections 
  f: 
  — 
  

  

  1. 
  Baryta 
  flint 
  glass 
  .... 
  Si, 
  Ba, 
  K. 
  

  

  2. 
  Ordinary 
  flint 
  glass 
  .... 
  Si, 
  Pb, 
  K. 
  

  

  3. 
  Plate 
  and 
  Window 
  glass 
  . 
  . 
  Si, 
  Ca, 
  Na. 
  

  

  4. 
  X-ray 
  glass 
  Si, 
  B, 
  Na. 
  

  

  All 
  the 
  above 
  glasses, 
  as 
  will 
  be 
  seen, 
  have 
  silicon 
  (Si) 
  as 
  

   their 
  principal 
  constituent, 
  the 
  transformation 
  ultimate 
  of 
  

   which 
  is 
  neon. 
  

  

  The 
  next 
  constituents 
  of 
  the 
  first 
  three 
  glasses, 
  barium 
  (Ba), 
  

   lead 
  (Pb),and 
  calcium 
  (Ca), 
  are 
  members 
  of 
  the 
  series 
  H2>i; 
  

   the 
  transformation 
  ultimate 
  of 
  which 
  is 
  helium. 
  

  

  The 
  alkali 
  metals, 
  sodium 
  (Na) 
  and 
  potassium 
  (K), 
  as 
  will 
  

   be 
  seen, 
  are 
  constituents 
  of 
  nearly 
  all 
  glasses, 
  and 
  their 
  trans- 
  

   formation 
  ultimate, 
  with 
  other 
  members 
  of 
  the 
  series 
  H?i, 
  is 
  

   hvdrooen. 
  Considering 
  the 
  wide 
  diffusion 
  of 
  this 
  element, 
  

   the 
  transformations 
  of 
  Hn 
  when 
  actually 
  effected 
  would 
  be 
  

   difficult 
  to 
  demonstrate. 
  One 
  of 
  the 
  two 
  principal 
  lines 
  in 
  

   the 
  spectrum 
  of 
  thallium 
  was 
  masked 
  completely 
  by 
  hydrogen 
  

   C 
  of 
  atmospheric 
  air 
  for 
  more 
  than 
  thirty 
  years, 
  when 
  I 
  

   discovered 
  it 
  in 
  the 
  arc 
  spectrum 
  while 
  engaged 
  in 
  another 
  

   research!. 
  

  

  As 
  the 
  transformation 
  of 
  radium 
  into 
  helium 
  was 
  first 
  

  

  * 
  ' 
  Nature,' 
  February 
  13 
  : 
  Chem. 
  News, 
  February 
  14, 
  1913. 
  

   t 
  Thorpe's 
  Di'ct. 
  of 
  Applied 
  Chemistrv, 
  Article 
  — 
  Glass. 
  

   t 
  Proc. 
  Rov. 
  Soc. 
  1893. 
  

  

  