﻿Browning 
  and 
  Minnig 
  — 
  Preparation 
  of 
  Telluric 
  Acid. 
  73 
  

  

  After 
  concentration 
  of 
  the 
  telluric 
  acid 
  solution, 
  the 
  acid 
  

   may 
  be 
  precipitated 
  by 
  nitric 
  acid, 
  washed 
  with 
  the 
  same 
  

   reagent 
  to 
  remove 
  the 
  hydrochloric 
  acid 
  and 
  then 
  with 
  acetone 
  

   or 
  ether 
  to 
  remove 
  the 
  nitric 
  acid. 
  This 
  modification 
  of 
  the 
  

   process, 
  however, 
  appeared 
  to 
  have 
  no 
  advantage 
  in 
  the 
  purity 
  

   of 
  the 
  product. 
  

  

  The 
  absence 
  of 
  contaminating 
  salts 
  is 
  practically 
  assured 
  by 
  

   the 
  method 
  described 
  if 
  the 
  elementary 
  tellurium 
  used 
  is 
  rea- 
  

   sonably 
  pure. 
  

  

  June, 
  1913. 
  

  

  SCIENTIFIC 
  INTELLIGENCE. 
  

  

  I. 
  Chemistry 
  and 
  Physics. 
  

  

  1. 
  Compounds 
  of 
  Trivalent 
  and 
  Quadrivalent 
  Tungsten. 
  — 
  

   That 
  tungsten 
  forms 
  compounds 
  of 
  at 
  least 
  one 
  lower 
  state 
  of 
  oxi- 
  

   dation 
  than 
  tungstic 
  acid, 
  W0 
  3 
  , 
  has 
  been 
  well 
  known 
  for 
  a 
  long 
  

   time, 
  as 
  the 
  beautiful 
  blue 
  color 
  produced 
  by 
  its 
  reduction 
  has 
  

   been 
  extensively 
  used 
  as 
  a 
  qualitative 
  test 
  for 
  the 
  element, 
  but 
  

   heretofore 
  little 
  has 
  been 
  known 
  in 
  regard 
  to 
  the 
  nature 
  of 
  the 
  

   reduction 
  products. 
  O. 
  Olsson, 
  however, 
  has 
  recently 
  succeeded 
  

   in 
  preparing 
  several 
  well-crystallized 
  compounds 
  of 
  trivalent 
  and 
  

   quadrivalent 
  tungsten. 
  By 
  reducing 
  strong 
  hydrochloric 
  acid 
  

   solutions 
  with 
  metallic 
  tin 
  he 
  obtained 
  the 
  double 
  salts 
  K 
  3 
  W 
  2 
  C1 
  9 
  

   and 
  (NH 
  4 
  ) 
  3 
  W 
  2 
  C1 
  9 
  , 
  which 
  show 
  the 
  existence 
  of 
  WC1 
  3 
  in 
  combina- 
  

   tion. 
  The 
  analogous 
  thallium, 
  calcium 
  and 
  rubidium 
  salts, 
  

   T1 
  3 
  W 
  2 
  C1 
  9 
  , 
  Cs 
  3 
  W 
  2 
  Cl 
  9 
  , 
  and 
  Rb 
  3 
  W 
  2 
  Cl 
  9 
  were 
  prepared 
  also. 
  These 
  

   salts 
  are 
  greenish 
  yellow 
  in 
  color, 
  they 
  are 
  fairly 
  stable 
  in 
  the 
  air 
  

   in 
  the 
  dry 
  solid 
  condition, 
  but 
  in 
  their 
  preparation 
  it 
  was 
  neces- 
  

   sary 
  to 
  protect 
  the 
  solutions 
  with 
  an 
  atmosphere 
  of 
  carbon 
  diox- 
  

   ide. 
  By 
  using 
  less 
  complete 
  reduction 
  by 
  means 
  of 
  tin 
  the 
  author 
  

   has 
  been 
  able 
  to 
  obtain 
  a 
  single 
  dark 
  green 
  salt, 
  which 
  appears 
  to 
  

   contain 
  quadrivalent 
  tungsten, 
  with 
  the 
  formula 
  K 
  2 
  W(0H)C1 
  5 
  . 
  

   — 
  Berichte, 
  xlvi, 
  566. 
  h. 
  l. 
  w. 
  

  

  2. 
  A 
  New 
  Oxide 
  of 
  Carbon. 
  — 
  H. 
  Meyer 
  and 
  K. 
  Steiner 
  have 
  

   succeeded 
  in 
  preparing 
  the 
  anhydride, 
  C 
  12 
  9 
  , 
  of 
  mellitic 
  acid. 
  This 
  

   is 
  a 
  benzol 
  derivative, 
  each 
  of 
  the 
  six 
  carbons 
  of 
  the 
  benzol 
  ring 
  

   being 
  combined 
  with 
  a 
  CO 
  group, 
  and 
  the 
  three 
  adjacent 
  pairs 
  of 
  

   CO 
  groups 
  being 
  connected 
  by 
  an 
  oxygen 
  atom. 
  The 
  compound 
  

   is 
  peculiar 
  in 
  containing 
  precisely 
  50 
  per 
  cent 
  each 
  of 
  carbon 
  and 
  

   hydrogen. 
  It 
  forms 
  brilliant, 
  colorless 
  crystals 
  which 
  are 
  very 
  

   stable, 
  and 
  may 
  be 
  dried 
  at 
  160° 
  C. 
  without 
  change. 
  The 
  sub- 
  

   stance 
  begins 
  to 
  darken 
  when 
  heated 
  above 
  320° 
  C, 
  and 
  it 
  burns 
  

  

  