﻿74 
  ScietvtifiG 
  Intelligence. 
  

  

  line, 
  Perkins 
  reaction, 
  the 
  constitution 
  of 
  benzene, 
  the 
  constitu- 
  

   tion 
  of 
  acetoacetic 
  ether, 
  the 
  uric 
  acid 
  group, 
  the 
  constitution 
  of 
  

   the 
  sugars, 
  the 
  isomerism 
  of 
  maleic 
  and 
  fumaric 
  acids, 
  the 
  isomer- 
  

   ism 
  of 
  the 
  oximes, 
  and 
  the 
  constitution 
  of 
  the 
  diazo 
  compounds. 
  

   The 
  work 
  will 
  be 
  useful 
  as 
  a 
  source 
  of 
  information 
  regarding 
  the 
  

   history 
  and 
  present 
  status 
  of 
  these 
  particular 
  topics, 
  and 
  it 
  will 
  be 
  

   valuable 
  also 
  in 
  giving 
  the 
  student 
  a 
  clear 
  idea 
  of 
  the 
  objects 
  of 
  

   chemical 
  research, 
  and 
  arousing 
  his 
  interest 
  in 
  the 
  literature. 
  

  

  II. 
  L. 
  w. 
  

  

  5. 
  Lehrhuch 
  der 
  Allgememen 
  Chemie. 
  Von 
  Dr. 
  Wilh. 
  Ost- 
  

   w^ALD. 
  Zweiten 
  Bandes, 
  Zweiter 
  Teil 
  : 
  Verwandtschaftslehre. 
  

   Yierte 
  Lieferung 
  : 
  Bogen 
  39-52 
  Mit 
  Figen 
  71-152. 
  Zweite 
  

   umgearbeitete 
  Auflage. 
  Leipzig, 
  1899 
  (Wm. 
  Engelmann). 
  — 
  

   Some 
  of 
  the 
  earlier 
  parts 
  of 
  this 
  fundamentally 
  important 
  work 
  

   have 
  been 
  already 
  noticed 
  in 
  this 
  Journal, 
  and 
  those 
  interested 
  

   are 
  well 
  acquainted 
  with 
  its 
  scope 
  and 
  value. 
  The 
  present 
  

   Fourth 
  Part 
  (pp. 
  625-828) 
  discusses 
  the 
  cases 
  of 
  Chemical 
  

   Equilibrium 
  of 
  the 
  Second 
  Order. 
  The 
  part 
  following 
  is 
  to 
  

   contain 
  those 
  of 
  the 
  Equilibrium 
  of 
  the 
  Third 
  and 
  Higher 
  Orders, 
  

   and 
  with 
  this 
  the 
  second 
  part 
  of 
  the 
  second 
  volume 
  will 
  be 
  brought 
  

   to 
  a 
  close. 
  

  

  6. 
  Insulators 
  for 
  Seat. 
  — 
  Walter 
  Hempel 
  has 
  made 
  a 
  com- 
  

   parison 
  of 
  the 
  relative 
  value 
  of 
  different 
  media 
  for 
  heat 
  insula- 
  

   tion, 
  and 
  gives 
  the 
  following 
  table 
  : 
  

  

  Temperatures 
  iu 
  the 
  interior 
  of 
  the 
  vessels. 
  

  

  Duration 
  of 
  time 
  in 
  minutes 
  

  

  5 
  32 
  58 
  88 
  TfS 
  ]60 
  207 
  

  

  Dry, 
  clean 
  sheep's 
  wool 
  (dried 
  ) 
  ^ 
  . 
  ^^ 
  „, 
  ^^ 
  

  

  at 
  100°) 
  i" 
  ~^^ 
  ~^^ 
  ~^^ 
  ~^" 
  

  

  Cottonwool 
  —76 
  —63 
  —56 
  —43 
  

  

  Silk 
  -76 
  -65 
  -58 
  -48 
  

  

  Moist 
  sheep's 
  wool 
  —76 
  —64 
  —54 
  —44 
  

  

  Clean 
  wool, 
  air 
  dried 
  —77 
  —74 
  —64 
  —55 
  

  

  Eiderdown 
  —78 
  —76 
  —67 
  —66 
  —49 
  —33 
  —17 
  

  

  Vacuum 
  tubes 
  of 
  D. 
  Bender 
  

  

  , 
  T^ 
  „ 
  ,, 
  . 
  .1 
  -66 
  -67 
  -49 
  -32 
  -8 
  +2 
  +8 
  

  

  and 
  D. 
  Holbein 
  \ 
  

  

  Vacuum 
  tubes 
  of 
  D. 
  Bender 
  /jj 
  _^^ 
  _^^ 
  _^g 
  _,^^ 
  _^^ 
  ^^ 
  ^3 
  

  

  and 
  D. 
  Holbem 
  [ 
  

  

  Weinhold-Dewar 
  tubes- 
  ( 
  _^g 
  _.^ 
  _^^ 
  _.q 
  ._g^ 
  _^^ 
  ..^ 
  

  

  Silvered 
  j 
  

  

  It 
  thus 
  appears 
  that 
  carefully 
  exhausted 
  vessels 
  give 
  a 
  better 
  

   means 
  of 
  heat 
  insulation 
  than 
  any 
  other 
  means, 
  while 
  partially 
  

   exhausted 
  vessels 
  are 
  inferior 
  to 
  the 
  other 
  means 
  in 
  the 
  above 
  

   \ht.— 
  Wiecl 
  Ann., 
  No. 
  5, 
  1899, 
  pp. 
  185-138. 
  J. 
  t. 
  

  

  '7. 
  Optical 
  relations 
  of 
  Gold 
  and 
  Platinum 
  layers. 
  — 
  This 
  is 
  an 
  

   examination 
  of 
  the 
  work 
  of 
  various 
  investigators 
  and 
  a 
  study 
  of 
  

   the 
  best 
  method 
  of 
  making 
  the 
  measures. 
  The 
  author, 
  G. 
  Breit- 
  

   HAUPT, 
  finds 
  that 
  a 
  method 
  by 
  Schmidt 
  permits 
  of 
  the 
  measure 
  of 
  

   the 
  index 
  of 
  refraction 
  of 
  metals. 
  Gold 
  gives 
  the 
  most 
  constant 
  

   values, 
  while 
  platinum 
  does 
  not 
  give 
  consistent 
  ones. 
  Mirrors 
  of 
  

   obsidian 
  proved 
  of 
  value 
  as 
  foundations 
  for 
  the 
  layers. 
  Burned- 
  

  

  