﻿Chemistry 
  and 
  Physics. 
  69 
  

  

  though 
  possibly 
  an 
  intermediate 
  stage 
  occurs 
  as 
  follows: 
  

  

  C,H 
  5 
  C^>N 
  a 
  H+(H 
  3 
  0) 
  2 
  = 
  C 
  r 
  H 
  5 
  C^ 
  H 
  + 
  N 
  2 
  + 
  NH, 
  

  

  the 
  benzhydroxamic 
  acid 
  splitting 
  into 
  aniline 
  and 
  carbon 
  dioxide; 
  

   benzenyl-tetrazotic 
  acid 
  may 
  be 
  considered 
  either 
  as 
  a 
  phenyl- 
  

  

  ^ 
  N 
  — 
  N 
  

  

  tetrazol 
  C 
  t 
  .H 
  5 
  .C^ 
  || 
  , 
  analogous 
  to 
  the 
  isomeric 
  compound 
  

  

  \NH-N 
  

  

  // 
  N 
  N 
  

  

  discovered 
  bv 
  Bladin 
  CH<( 
  || 
  , 
  or 
  as 
  an 
  imido 
  comj>ound 
  

  

  X 
  N(C 
  6 
  H 
  5 
  ).N 
  ^N 
  

  

  corresponding 
  to 
  thebenzoyl-azoimicleof 
  CurtiusC 
  6 
  H 
  5 
  . 
  CO. 
  N 
  || 
  , 
  

  

  in 
  the 
  latter 
  case 
  having 
  the 
  formula 
  C 
  f 
  H 
  5 
  C(NH) 
  . 
  N 
  || 
  ; 
  (c) 
  since 
  

  

  benzenyl-oxytetrazotic 
  acid 
  does 
  not 
  give 
  Liebermann's 
  reaction, 
  

   it 
  is 
  not 
  a 
  nitro-compound. 
  According 
  to 
  C. 
  Lossen, 
  benzenyl- 
  

   oxytetrazotic 
  acid 
  crystallizes 
  from 
  ■ 
  boiling 
  water 
  in 
  rhombic 
  

   needles 
  which 
  fuse 
  with 
  decomposition 
  at 
  175°. 
  With 
  one 
  mole- 
  

   cule 
  of 
  crystal 
  water 
  the 
  acid 
  is 
  permanent, 
  but 
  when 
  deprived 
  

   of 
  this 
  water 
  at 
  105°, 
  it 
  readily 
  decomposes 
  evolving 
  nitrous 
  

   vapors. 
  Its 
  salts 
  with 
  potassium, 
  barium 
  and 
  silver 
  are 
  described. 
  

   Benzenyl-tetrazotic 
  acid 
  crystallizes 
  from 
  hot 
  water, 
  better 
  from 
  

   alcohol 
  in 
  rhombic 
  hemimorphic 
  colorless 
  needles, 
  fusing 
  at 
  212° 
  

   to 
  213° 
  with 
  decomposition. 
  By 
  slowly 
  heating 
  it, 
  a 
  beautiful 
  

   red 
  mass 
  is 
  obtained 
  ; 
  w 
  7 
  hile 
  on 
  rapid 
  heating 
  a 
  violent 
  decomposi- 
  

   tion 
  results, 
  often 
  with 
  ignition, 
  a 
  dark 
  green 
  tenacious 
  residue 
  

   being 
  left 
  in 
  the 
  test-tube, 
  whose 
  vapor 
  is 
  red 
  or 
  violet. 
  The 
  dioxy- 
  

   tetrazotic 
  acid 
  affords 
  a 
  meta-nitro-derivative 
  m-nitrobenzenyl- 
  

   dioxytetrazotic 
  acid. 
  — 
  Liebig's 
  Annalen, 
  cclxiii, 
  73 
  ; 
  JBer. 
  Berl. 
  

   Ghem. 
  Ges., 
  xxiv, 
  392, 
  May, 
  1891. 
  g. 
  f. 
  b. 
  

  

  7. 
  Polar 
  light 
  and 
  Cosmic 
  dust. 
  — 
  Liveino 
  and 
  Dewae 
  ob- 
  

   tained 
  metallic 
  dust 
  by 
  means 
  of 
  electrical 
  discharges 
  between 
  

   terminals 
  of 
  different 
  metals 
  inserted 
  in 
  a 
  glass 
  receptacle 
  — 
  

   from 
  this 
  the 
  dust 
  was 
  conveyed 
  by 
  means 
  of 
  a 
  stream 
  of 
  hydro- 
  

   gen 
  into 
  an 
  end-on-tube, 
  through 
  which 
  electrical 
  discharges 
  

   were 
  passed. 
  The 
  spectrum 
  of 
  these 
  discharges 
  showed 
  no 
  trace 
  

   of 
  the 
  lines 
  of 
  the 
  finely 
  divided 
  metals 
  although 
  the 
  finely 
  

   divided 
  dust 
  was 
  present 
  in 
  great 
  abundance. 
  They 
  therefore 
  

   conclude 
  that 
  if 
  the 
  northern 
  lights 
  are 
  due 
  to 
  great 
  electric 
  dis- 
  

   charges 
  through 
  rarified 
  air 
  filled 
  with 
  cosmic 
  dust, 
  conditions 
  

   must 
  exist 
  which 
  are 
  different 
  from 
  those 
  in 
  the 
  experiment 
  

   devised 
  by 
  them. 
  — 
  Proc. 
  Roy. 
  Soc, 
  xlviii, 
  p. 
  437-440, 
  1891. 
  

  

  J. 
  T. 
  

  

  8. 
  Phosphorescence. 
  — 
  E. 
  Wiedermann 
  has 
  investigated 
  the 
  

   character 
  of 
  the 
  light 
  given 
  out 
  by 
  Balmain's 
  paint 
  under 
  different 
  

   conditions 
  of 
  exposure. 
  He 
  expresses 
  his 
  belief 
  that 
  a 
  source 
  of 
  

   light 
  which 
  sends 
  forth 
  proportionally 
  more 
  light 
  waves 
  than 
  

   heat 
  waves, 
  as 
  Langley 
  maintains 
  is 
  the 
  case 
  with 
  the 
  fire 
  fly, 
  is 
  not 
  

  

  