﻿Chemistry 
  and 
  Physics. 
  151 
  

  

  made 
  to 
  secure 
  larger 
  quantities, 
  by 
  operating 
  in 
  the 
  larger 
  

   vessel. 
  But 
  it 
  was 
  found 
  that 
  here 
  the 
  chloroform 
  could 
  be 
  

   cooled 
  to 
  —81° 
  without 
  a 
  trace 
  of 
  crystallization. 
  Indeed 
  chloro- 
  

   form 
  crystals 
  produced 
  in 
  the 
  smaller 
  vessel 
  at 
  — 
  68 
  # 
  5°, 
  dissolved 
  

   at 
  once 
  when 
  placed 
  in 
  the 
  larger 
  one 
  at 
  —81°. 
  Finally 
  the 
  

   whole 
  tube 
  with 
  crystals 
  on 
  its 
  walls 
  and 
  liquid 
  surrounding 
  them, 
  

   was 
  immersed 
  at 
  —68*5° 
  in 
  the 
  liquid 
  chloroform 
  at 
  —81°. 
  And 
  

   although 
  the 
  thermometer 
  fell 
  from 
  the 
  higher 
  to 
  the 
  lower 
  tem- 
  

   perature, 
  the 
  crystals 
  actually 
  dissolved 
  before 
  the 
  observer's 
  

   eyes. 
  The 
  author 
  accounts 
  for 
  this 
  result 
  on 
  certain 
  theories 
  of 
  

   his 
  own 
  concerning 
  radiation. 
  — 
  Nature, 
  li, 
  20, 
  November, 
  1894. 
  

   See 
  also 
  C. 
  JR. 
  cxix, 
  554, 
  1»94. 
  g. 
  f. 
  b. 
  

  

  6. 
  On 
  Symmetrical 
  Di-ethyl 
  hydrazine. 
  — 
  Although 
  the 
  dis- 
  

   coverer 
  of 
  hydrazine, 
  Curtius, 
  succeeded 
  in 
  obtaining 
  the 
  sym- 
  

   metrical 
  di-benzyl 
  hydrazine 
  and 
  Fischer 
  the 
  unsymmetrical 
  

   di-ethyl 
  hydrazine, 
  yet 
  it 
  is 
  only 
  recently 
  that 
  the 
  symmetrical 
  

   di-ethyl 
  derivative 
  of 
  hydrazine 
  C 
  2 
  H 
  5 
  NH.NHC 
  2 
  H 
  B 
  , 
  or 
  symmetrical 
  

   hydrazo-ethane, 
  has 
  been 
  isolated. 
  This 
  has 
  been 
  done 
  by 
  

   Haeries 
  in 
  the 
  laboratory 
  of 
  the 
  University 
  of 
  Berlin, 
  by 
  a 
  

   somewhat 
  indirect 
  though 
  in 
  practice 
  quite 
  simple 
  series 
  of 
  reac- 
  

   tions. 
  As 
  the 
  first 
  step, 
  a 
  remarkable 
  hydrazine 
  derivative 
  was 
  

   first 
  prepared 
  by 
  acting 
  on 
  di-formyl 
  hydrazine 
  with 
  sodium 
  and 
  

   then 
  decomposing 
  the 
  product 
  with 
  lead 
  acetate. 
  In 
  this 
  deriva- 
  

   tive 
  one 
  hydrogen 
  atom 
  of 
  each 
  amidogen 
  radical 
  was 
  replaced 
  

   by 
  the 
  radical 
  formvl 
  and 
  the 
  other 
  by 
  lead 
  ; 
  its 
  constitution 
  

  

  OHO— 
  "N\ 
  

   bein^ 
  | 
  ^Pb. 
  When 
  warmed 
  in 
  a 
  sealed 
  tube 
  with 
  ethyl 
  

  

  S 
  CHO-N/ 
  

   iodide, 
  together 
  with 
  sand 
  and 
  magnesia, 
  the 
  lead 
  atom 
  is 
  replaced 
  

   by 
  two 
  ethyl. 
  groups. 
  The 
  substance 
  thus 
  obtained, 
  a 
  volatile 
  

   liquid, 
  is 
  then 
  treated 
  with 
  fuming 
  hydrogen 
  chloride, 
  which 
  

   removes 
  the 
  formyl 
  groups 
  and 
  produces 
  the 
  hydrochloride 
  of 
  

   symmetrical 
  di-ethyl 
  hydrazine 
  ; 
  the 
  free 
  substance 
  passing 
  over 
  

   at 
  85° 
  on 
  distillation 
  with 
  potassium 
  hydrate. 
  It 
  is 
  a 
  liquid 
  

   with 
  an 
  agreeable 
  ethereal 
  odor 
  which 
  reduces 
  Fehling's 
  solution 
  

   with 
  great 
  energy 
  and 
  also 
  silver 
  nitrate 
  even 
  in 
  the 
  cold. 
  

   Toward 
  certain 
  oxidizing 
  agents, 
  especially 
  yellow 
  mercuric 
  

   oxide, 
  it 
  reacts 
  violently, 
  yielding 
  mercury 
  di-ethyl 
  and 
  azoethane 
  

   C 
  a 
  H 
  6 
  N=NC 
  2 
  H 
  6 
  .— 
  Ber. 
  Berl. 
  Chem. 
  Ges., 
  xxvii, 
  2276, 
  September, 
  

  

  1894. 
  G. 
  F. 
  B. 
  

  

  V. 
  On 
  Carbazide 
  and 
  Di-urea. 
  — 
  In 
  conjunction 
  with 
  Curtius, 
  

   Heideneeich 
  has 
  produced 
  two 
  remarkable 
  nitrogen 
  compounds, 
  

   one 
  of 
  which 
  is 
  carbazide 
  or 
  carbonyl 
  nitride 
  CON~ 
  G 
  and 
  the 
  other 
  

   is 
  di-urea 
  CO(NH.NH) 
  2 
  CO. 
  The 
  former 
  is 
  produced 
  by 
  the 
  

   action 
  of 
  sodium 
  nitrite 
  on 
  the 
  hydrochloride 
  of 
  carbohydrazide. 
  

   It 
  is 
  a 
  colorless 
  oil 
  which 
  explodes 
  violently 
  on 
  being 
  touched. 
  

  

  The 
  latter 
  is 
  obtained 
  when 
  the 
  compound 
  -j 
  MLT.nnnn 
  2 
  !.] 
  5 
  1S 
  

  

  heated 
  to 
  100° 
  with 
  hydrazine 
  hydrate 
  in 
  a 
  sealed 
  tube. 
  It 
  is 
  

   crystalline 
  and 
  very 
  stable 
  and 
  acts 
  like 
  a 
  strong 
  monobasic 
  acid. 
  

   —Ber. 
  Berl. 
  Chem. 
  Ges., 
  xxvii, 
  2684, 
  October, 
  1894. 
  g. 
  f. 
  b. 
  

  

  