﻿418 
  Scientific 
  Intelligence. 
  

  

  heated 
  nearly 
  to 
  boiling 
  and 
  2 
  or 
  3 
  CC 
  of 
  nitric 
  acid, 
  sp. 
  gr. 
  1*40, 
  

   are 
  added 
  drop 
  by 
  drop. 
  A 
  violent 
  reaction 
  takes 
  place 
  by 
  which 
  

   all 
  the 
  tungsten 
  is 
  precipitated 
  as 
  tungstic 
  acid 
  and 
  all 
  the 
  

   chromium 
  and 
  iron 
  go 
  into 
  solution. 
  After 
  a 
  few 
  minutes, 
  when 
  

   the 
  reaction 
  is 
  finished 
  the 
  liquid 
  is 
  diluted, 
  then 
  the 
  precipitate 
  

   is 
  allowed 
  to 
  settle 
  and 
  is 
  filtered 
  and 
  washed 
  with 
  dilute 
  hydro- 
  

   chloric 
  acid 
  (1:10). 
  In 
  this 
  way, 
  the 
  author 
  states 
  all 
  the 
  tung- 
  

   sten 
  is 
  obtained 
  entirely 
  free 
  from 
  silicon 
  and 
  chromium. 
  — 
  

   Zeitschr. 
  f. 
  analyt. 
  Chem., 
  lii, 
  529. 
  h. 
  l. 
  w. 
  

  

  5. 
  Qualitative 
  Chemical 
  Analysis; 
  by 
  Arthur 
  A. 
  Noyes. 
  

   Fourth 
  Edition. 
  Completely 
  rewritten. 
  8vo, 
  pp. 
  110. 
  New 
  

   York, 
  1913 
  (The 
  Macmillan 
  Company). 
  — 
  The 
  first 
  edition 
  of 
  this 
  

   well-known 
  laboratory 
  manual 
  appeared 
  twenty 
  years 
  ago. 
  It 
  

   has 
  been 
  improved 
  and 
  somewhat 
  enlarged 
  in 
  the 
  second 
  and 
  

   third 
  editions, 
  and 
  now 
  it 
  has 
  been 
  thoroughly 
  revised 
  as 
  a 
  result 
  

   of 
  the 
  extended 
  investigations 
  that 
  have 
  been 
  made 
  in 
  the 
  author's 
  

   laboratory 
  during 
  the 
  past 
  six 
  years. 
  The 
  process 
  of 
  analysis 
  has 
  

   thus 
  been 
  made 
  much 
  more 
  reliable, 
  so 
  that 
  now 
  it 
  is 
  possible, 
  the 
  

   author 
  states, 
  to 
  detect 
  one 
  milligram, 
  or 
  in 
  a 
  few 
  cases 
  two 
  milli- 
  

   grams, 
  of 
  any 
  constituent 
  in 
  the 
  presence 
  of 
  500 
  milligrams 
  of 
  

   any 
  other. 
  The 
  methods 
  employed 
  for 
  the 
  detection 
  of 
  the 
  

   metals 
  are 
  practically 
  all 
  well 
  known 
  and 
  require 
  no 
  special 
  com- 
  

   ment 
  here. 
  The 
  procedure 
  for 
  the 
  detection 
  of 
  the 
  acid 
  radicals 
  

   has 
  been 
  greatly 
  modified 
  by 
  introducing 
  a 
  distillation 
  with 
  phos- 
  

   phoric 
  acid. 
  The 
  first 
  half 
  of 
  this 
  distillate 
  is 
  collected 
  in 
  barium 
  

   hydroxide 
  solution, 
  the 
  second 
  half 
  in 
  water 
  ; 
  then 
  metallic 
  cop- 
  

   per 
  is 
  added 
  to 
  the 
  residue 
  and 
  a 
  third 
  distillate 
  is 
  obtained 
  con- 
  

   taining 
  sulphur 
  dioxide 
  in 
  case 
  sulphates 
  are 
  present, 
  and 
  

   applying 
  even 
  in 
  the 
  case 
  of 
  barinm 
  sulphate. 
  This 
  distillation 
  

   with 
  phosphoric 
  acid 
  is 
  not 
  intended 
  to 
  be 
  applied 
  in 
  simpler 
  

   cases, 
  and 
  it 
  may 
  be 
  regarded 
  as 
  a 
  rather 
  difficult 
  and 
  complex 
  

   operation 
  for 
  ordinary 
  students 
  in 
  qualitative 
  analysis, 
  and, 
  

   therefore, 
  its 
  general 
  adoption 
  appears 
  to 
  be 
  doubtful, 
  h. 
  l. 
  w. 
  

  

  6. 
  A 
  New 
  Fluorescence 
  Spectrum 
  of 
  Iodine. 
  — 
  The 
  shortest 
  

   wave-length 
  recorded 
  by 
  R. 
  W. 
  Wood 
  for 
  the 
  resonance 
  spec- 
  

   trum 
  of 
  iodine 
  vapor 
  when 
  excited 
  by 
  the 
  o 
  three 
  very 
  intense 
  vis- 
  

   ible 
  radiations 
  from 
  mercury 
  is 
  533 
  7*63 
  A.U. 
  Hoping 
  to 
  find 
  

   fluorescence 
  lines 
  of 
  shorter 
  wave-length, 
  J. 
  C. 
  McLennan 
  has 
  

   recently 
  repeated 
  Wood's 
  experiments, 
  endeavoring, 
  at 
  the 
  same 
  

   time, 
  to 
  obtain 
  more 
  intense 
  illumination, 
  especially 
  in 
  the 
  ultra- 
  

   violet. 
  Although 
  no 
  new 
  resonance 
  " 
  lines 
  " 
  were 
  found, 
  the 
  

   investigator's 
  labors 
  were 
  crowned 
  with 
  the 
  discovery 
  of 
  a 
  fluo- 
  

   rescent 
  band 
  spectrum 
  of 
  iodine 
  vapor. 
  

  

  The 
  special 
  form 
  of 
  lamp 
  which 
  produced 
  this 
  spectrum 
  may 
  

   be 
  briefly 
  described 
  as 
  follows: 
  The 
  outer 
  wall 
  was 
  of 
  the 
  usual 
  

   Cooper- 
  Hewitt 
  design 
  with 
  mercury 
  electrodes. 
  In 
  the 
  end 
  of 
  

   this 
  wall, 
  which 
  extended 
  some 
  distance 
  beyond 
  the 
  lateral 
  elec- 
  

   trode, 
  a 
  hole 
  was 
  made 
  and 
  then 
  a 
  long 
  tube 
  of 
  clear, 
  fused 
  

   quartz 
  was 
  sealed 
  at 
  the 
  hole 
  in 
  such 
  a 
  manner 
  as 
  to 
  remain 
  

   coaxial 
  with 
  the 
  surrounding 
  vessel. 
  Thus 
  the 
  inner 
  end 
  of 
  the 
  

  

  