﻿64 
  Scientific 
  Intelligence. 
  

  

  the 
  matter 
  he 
  crystallized 
  parazoxyanisoil 
  from 
  (a) 
  acetone, 
  (b) 
  

   alcohol 
  and 
  (c) 
  chloroform. 
  As 
  he 
  was 
  unable 
  to 
  detect 
  any 
  

   appreciable 
  change 
  of 
  the 
  transition-point, 
  he 
  concludes 
  that 
  the 
  

   view 
  of 
  Lehmann 
  is 
  the 
  more 
  probably 
  correct. 
  It 
  has 
  been 
  

   pointed 
  out 
  by 
  Ostwald 
  that 
  the 
  stability-interval 
  of 
  crystalline 
  

   liquids 
  must 
  be 
  near 
  the 
  critical 
  point 
  for 
  solid 
  and 
  liquid; 
  i. 
  e., 
  

   near 
  the 
  temperature 
  at 
  which 
  the 
  heat 
  of 
  fusion 
  is 
  zero. 
  By 
  

   means 
  of 
  the 
  specific 
  heats 
  of 
  the 
  crystalline 
  and 
  the 
  isotropic 
  

   liquids, 
  the 
  difference 
  between 
  the 
  transition 
  and 
  critical 
  tem- 
  

   peratures 
  is 
  calculated 
  as 
  (l) 
  27'6° 
  and 
  (2) 
  18*4°. 
  The 
  difference 
  

   in 
  these 
  values 
  may 
  perhaps 
  be 
  due 
  to 
  dimorphism 
  of 
  the 
  com- 
  

   pound. 
  Hence 
  the 
  author 
  considers 
  desirable 
  further 
  determina- 
  

   tions 
  with 
  other 
  compounds. 
  — 
  Zeitschr. 
  physikal. 
  Chew.., 
  xxviii, 
  

   280-288, 
  March, 
  1899. 
  G. 
  r. 
  b. 
  

  

  6. 
  On 
  the 
  Density 
  of 
  Liquid 
  Air, 
  and 
  of 
  other 
  liquefied 
  Gases. 
  — 
  

   Experiments 
  have 
  been 
  made 
  by 
  Ladenburg 
  and 
  Krugel 
  to 
  

   determine 
  the 
  density 
  of 
  liquefied 
  air 
  and 
  other 
  gases. 
  For 
  this 
  

   purpose 
  they 
  made 
  use 
  of 
  glass 
  rods, 
  whose 
  density 
  had 
  been 
  

   carefully 
  determined 
  by 
  weighing 
  in 
  air 
  and 
  in 
  water 
  at 
  4°. 
  By 
  

   means 
  of 
  a 
  Mohr's 
  balance 
  these 
  rods 
  were 
  carefully 
  weighed 
  in 
  

   the 
  liquefied 
  gases, 
  the 
  decrease 
  in 
  weight 
  being 
  accurately 
  noted. 
  

   No 
  correction 
  was 
  made 
  for 
  the 
  buoyancy 
  of 
  the 
  atmosphere, 
  and 
  

   none 
  for 
  the 
  contraction 
  in 
  volume 
  of 
  the 
  glass, 
  as 
  its 
  coefficient 
  

   for 
  these 
  low 
  temperatures 
  was 
  not 
  known. 
  In 
  the 
  case 
  of 
  

   liquid 
  air 
  the 
  authors 
  determined 
  simultaneously 
  its 
  composition. 
  

   They 
  found 
  (1) 
  that 
  freshly 
  liquefied 
  air 
  had 
  a 
  density 
  of 
  0*9951, 
  

   and 
  contained 
  58*83 
  per 
  cent 
  of 
  oxygen. 
  (2) 
  That 
  after 
  several 
  

   hours, 
  the 
  density 
  increased 
  to 
  1*029, 
  when 
  it 
  contained 
  84*2 
  per 
  

   cent 
  of 
  oxygen. 
  (3) 
  That 
  after 
  standing 
  for 
  2 
  or 
  3 
  days 
  

   until 
  most 
  of 
  the 
  nitrogen 
  had 
  evaporated, 
  the 
  density 
  rose 
  to 
  

   1*112, 
  there 
  being 
  present 
  in 
  it 
  93*6 
  per 
  cent 
  of 
  oxygen. 
  The 
  

   authors, 
  therefore, 
  conclude 
  that 
  the 
  density 
  of 
  a 
  liquid 
  contain- 
  

   ing 
  20*9 
  per 
  cent 
  of 
  oxygen 
  would 
  be 
  0*87-0*90. 
  Liquid 
  oxygen 
  

   pure 
  has 
  a 
  density 
  slightly 
  lower 
  than 
  the 
  above 
  mentioned 
  mix- 
  

   ture 
  containing 
  93*6 
  per 
  cent 
  of 
  it, 
  being 
  1-105-1*108. 
  The 
  fus- 
  

   ing 
  point 
  of 
  ethylene 
  was 
  found 
  to 
  be 
  —169° 
  and 
  the 
  boiling 
  

   point 
  —105*4° 
  at 
  760 
  mm 
  pressure; 
  the 
  values 
  given 
  by 
  Olszewski 
  

   being 
  the 
  same 
  for 
  the 
  fusing 
  point 
  but 
  —102*5° 
  for 
  the 
  boiling 
  

   poiut. 
  The 
  density 
  of 
  the 
  liquid 
  at 
  —169° 
  was 
  noted 
  as 
  0*6585 
  

   and 
  at 
  —105*4°, 
  0*571.— 
  Ber. 
  Berl 
  Chem. 
  Ges., 
  xxxii, 
  46-49, 
  

   1899. 
  G. 
  F. 
  B. 
  

  

  7. 
  Lemons 
  de 
  Chemie 
  Physique, 
  professees 
  a 
  l'Universite 
  de 
  

   Berlin. 
  Par 
  J. 
  H. 
  Van't 
  Hoff, 
  Professor 
  ordinaire 
  a 
  l'Univer- 
  

   site. 
  Traduit 
  de 
  l'allemand 
  par 
  M. 
  Corvisy. 
  Deuxieme 
  Partie. 
  

   La 
  Statique 
  Chimique. 
  8vo, 
  pp. 
  162. 
  Paris, 
  1899 
  (Hermann). 
  — 
  

   This 
  is 
  the 
  second 
  part 
  of 
  Professor 
  Van't 
  Hoff's 
  Berlin 
  lectures, 
  

   the 
  first 
  part 
  having 
  been 
  noticed 
  in 
  this 
  Journal 
  for 
  February, 
  

   1899, 
  p. 
  157. 
  G. 
  f. 
  b. 
  

  

  8. 
  Lehrbuch 
  der 
  Allgerneinen 
  Chemie; 
  von 
  Dr. 
  Wilh. 
  Ost- 
  

   wald. 
  Zweite 
  umgearbeitete 
  Auflage 
  in 
  zwei 
  Banden. 
  Zweiten 
  

   Bandes 
  Zweiter 
  Teil. 
  Verwandtschaftslehre, 
  Vierte 
  Lieferung, 
  

  

  