﻿Chemistry 
  and 
  Physics. 
  143 
  

  

  SCIENTIFIC 
  INTELLIGENCE. 
  

  

  I. 
  Chemistry 
  and 
  Physics. 
  

  

  1. 
  On 
  the 
  third 
  Radioactive 
  substance 
  in 
  Pitchblende. 
  — 
  In 
  

   the 
  belief 
  that 
  other 
  radioactive 
  substances 
  occur 
  in 
  uraninite 
  

   besides 
  polonium 
  and 
  radium, 
  Debierne, 
  at 
  the 
  suggestion 
  of 
  

   M. 
  and 
  Mine. 
  Curie, 
  has 
  made 
  a 
  further 
  examination 
  of 
  this 
  

   mineral 
  in 
  the 
  laboratory 
  of 
  the 
  Sorbonne; 
  giving 
  especial 
  atten- 
  

   tion 
  to 
  those 
  substances 
  whose 
  acid 
  solutions 
  are 
  not 
  precipitated 
  

   by 
  hydrogen 
  sulphide, 
  but 
  which 
  are 
  completely 
  precipitated 
  by 
  

   ammonia 
  and 
  ammonium 
  sulphide. 
  The 
  crude 
  material 
  employed 
  

   came 
  from 
  an 
  Austrian 
  chemical 
  works 
  where 
  uranium 
  com- 
  

   pounds 
  were 
  made 
  from 
  pitchblende, 
  and 
  hence 
  contained 
  these 
  

   compounds 
  only 
  in 
  small 
  quantities. 
  Since 
  the 
  quantity 
  of 
  radio- 
  

   active 
  substance 
  was 
  very 
  small, 
  even 
  in 
  this 
  residue, 
  the 
  several 
  

   hundred 
  kilograms 
  ^ised 
  were 
  first 
  treated 
  so 
  as 
  to 
  eliminate 
  

   polonium 
  and 
  radium 
  as 
  completely 
  as 
  possible. 
  The 
  larger 
  por- 
  

   tion 
  of 
  the 
  ammonia 
  precipitate 
  was 
  made 
  up 
  of 
  alumina 
  and 
  

   iron 
  oxide, 
  though 
  ziuc, 
  manganese, 
  chromium, 
  vanadium, 
  

   uranium, 
  titanium, 
  columbium 
  and 
  tantalum 
  were 
  also 
  present 
  

   in 
  minute 
  quantities, 
  as 
  were 
  also 
  lanthanum, 
  didymium, 
  cerium 
  

   and 
  the 
  yttrite 
  earths. 
  As 
  the 
  other 
  elements 
  were 
  successively 
  

   separated, 
  the 
  new 
  substance 
  became 
  concentrated, 
  the 
  portion 
  

   containing 
  the 
  titanium 
  and 
  its 
  analogues 
  showing 
  radioactivity 
  

   very 
  intensely. 
  A 
  product 
  was 
  finally 
  obtained 
  giving 
  the 
  prin- 
  

   cipal 
  reactions 
  of 
  titanium, 
  but 
  which 
  emitted 
  extremely 
  active 
  

   rays, 
  a 
  fraction, 
  by 
  a 
  rough 
  determination, 
  being 
  estimated 
  to 
  be 
  

   a 
  hundred 
  thousand 
  times 
  more 
  active 
  than 
  uranium. 
  While 
  its 
  

   chemical 
  properties 
  are 
  entirely 
  different 
  from 
  those 
  of 
  polonium 
  

   and 
  radium, 
  its 
  radiations 
  are 
  entirely 
  comparable 
  to 
  those 
  given 
  

   out 
  by 
  these 
  elements. 
  They 
  discharge 
  electrified 
  bodies, 
  they 
  

   excite 
  phosphorescence 
  of 
  a 
  barium-platinocyanide 
  screen 
  and 
  

   they 
  act 
  on 
  the 
  photographic 
  plate. 
  The 
  new 
  substance, 
  how- 
  

   ever, 
  is 
  not 
  self-luminous, 
  as 
  Mme. 
  Curie 
  has 
  shown 
  radium 
  to 
  

   be. 
  — 
  C. 
  It., 
  cxxix, 
  503, 
  October, 
  1899. 
  g. 
  f. 
  b. 
  

  

  2. 
  On 
  the 
  Spectrum 
  of 
  Radium. 
  — 
  Having 
  received 
  at 
  various 
  

   times 
  from 
  M. 
  and 
  Mme. 
  Curie 
  specimens 
  of 
  barium 
  chloride 
  

   containing 
  radium 
  in 
  progressively 
  increasing 
  quantities, 
  Demar- 
  

   cay 
  has 
  submitted 
  these 
  to 
  spectrum 
  examination 
  and 
  finds 
  not 
  

   only 
  that 
  with 
  the 
  increase 
  of 
  radio-activity 
  the 
  line 
  of 
  wave 
  

   length 
  3814-8, 
  observed 
  by 
  him 
  a 
  year 
  ago, 
  becomes 
  stronger, 
  

   but 
  that 
  new 
  lines 
  also 
  make 
  their 
  appearance. 
  In 
  the 
  last 
  speci- 
  

   men 
  examined 
  the 
  radio-activity 
  was 
  about 
  1*7 
  X 
  10 
  4 
  times 
  that 
  

   of 
  uranium. 
  Its 
  spectrum 
  was 
  photographed 
  in 
  the 
  ordinary 
  

   way 
  and 
  was 
  found 
  to 
  contain 
  lines 
  between 
  wave 
  lengths 
  5000 
  

   to 
  3500. 
  This 
  spectrum 
  showed 
  (1) 
  a 
  very 
  intense 
  and 
  complete 
  

   spectrum 
  of 
  barium 
  ; 
  (2) 
  the 
  spectrum 
  of 
  the 
  platinum 
  electrodes 
  

  

  