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  124 
  j 
  

   XII. 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  ON 
  THE 
  COND 
  ACTIVITY 
  OF 
  CARBON 
  FOR 
  HEAT 
  AND 
  ELECTRICITY. 
  

  

  BY 
  L. 
  CELLIER. 
  

  

  rPHE 
  results 
  of 
  this 
  investigation 
  are 
  contained 
  in 
  the 
  following 
  

   -*- 
  table, 
  in 
  which 
  T 
  is 
  the 
  temperature 
  ; 
  K 
  B 
  the 
  conductivity 
  for 
  

   heat; 
  K 
  e 
  the 
  conductivity 
  for 
  electricity; 
  and 
  c 
  l 
  the 
  specific 
  heat 
  

   of 
  unit 
  volume 
  : 
  — 
  

  

  

  T. 
  

  

  e 
  v 
  

  

  K 
  w 
  . 
  

  

  K 
  e 
  . 
  

  

  13-049x10-9 
  

   185-36x10-9 
  

  

  267-88x10-9 
  

   146-32x10-9 
  

  

  

  Graphite 
  

  

  6° 
  84 
  

   9-04 
  

  

  783 
  

   904 
  

  

  0-3055 
  

   0-2782 
  

  

  0-2667 
  

  

  0-2488 
  

  

  0-701 
  

   0-400 
  

  

  0-494 
  

   0-367 
  

  

  53-72 
  xl0 
  G 
  

   2158 
  xlO 
  6 
  

  

  1-844 
  xlO 
  6 
  

   2-509 
  x 
  10 
  6 
  

  

  ; 
  

  

  Gas 
  Graphite 
  

  

  Arc 
  Light 
  Charcoal 
  of 
  1 
  

   Paris 
  [ 
  

  

  Arc 
  Light 
  Charcoal 
  of"! 
  

   Siemens 
  and 
  Halske 
  J 
  

  

  =a+6c,, 
  

  

  (1) 
  

  

  Professor 
  Weber 
  found 
  for 
  metals 
  that 
  

  

  where 
  

  

  rt 
  = 
  5-28xlO 
  l 
  , 
  

  

  6=8-l9xl0 
  4 
  . 
  

  

  The 
  table 
  of 
  the 
  values 
  of 
  the 
  quotient 
  K 
  w 
  /K 
  e 
  shows 
  distinctly 
  

   that 
  such 
  a 
  relation 
  does 
  not 
  hold 
  in 
  the 
  case 
  of 
  cirbon 
  ; 
  further, 
  that 
  

   carbon 
  cannot 
  be 
  at 
  all 
  compared 
  with 
  metals, 
  for 
  while 
  in 
  the 
  

   latter 
  the 
  ratio 
  K 
  w 
  /K 
  e 
  varies 
  between 
  0*07 
  x 
  10 
  6 
  and 
  0'12 
  x 
  10 
  6 
  , 
  in 
  

   the 
  former 
  it 
  varies 
  between 
  1'8xl0 
  6 
  and 
  53*72 
  x 
  10 
  6 
  . 
  The 
  

   thermal 
  conductivity 
  is 
  \b 
  to 
  20 
  times 
  as 
  much 
  as 
  would 
  be 
  

   deduced 
  from 
  the 
  above 
  ratio 
  by 
  means 
  of 
  the 
  specific 
  heat 
  and 
  

   the 
  electrical 
  conductivity. 
  This 
  relation 
  between 
  the 
  two 
  con- 
  

   ductivities 
  appears 
  to 
  be 
  connected 
  with 
  the 
  metallic 
  nature 
  of 
  the 
  

   substances. 
  — 
  Wiedemann's 
  Annalen, 
  No. 
  7, 
  1897. 
  

  

  THE 
  GENESIS 
  OF 
  DALTON 
  S 
  ATOMIC 
  THEORY. 
  

   BY 
  H. 
  DEBUS, 
  PH.D., 
  F.R.S. 
  

  

  Sir 
  H. 
  Roscoe 
  and 
  Mr. 
  A. 
  Harden 
  have 
  published 
  in 
  the 
  

   Phil. 
  Mag. 
  (March 
  1897) 
  a 
  paper 
  on 
  the 
  (xenesis 
  of 
  Dalton's 
  

   Atomic 
  Theory, 
  wherein 
  several 
  statements 
  are 
  made 
  against 
  the 
  

   views 
  held 
  by 
  me. 
  These 
  statements 
  of 
  Messrs. 
  Eoscoe 
  and 
  

   Harden 
  are, 
  in 
  my 
  opinion, 
  erroneous. 
  I 
  have 
  fully 
  answered 
  

   them 
  in 
  a 
  paper 
  published 
  in 
  the 
  Zeitschrift 
  fur 
  phi/sikalische 
  

   Chemie 
  von 
  W. 
  Ostwald 
  and 
  J. 
  H. 
  van't 
  Hoff, 
  vol. 
  xxiv. 
  p. 
  325, 
  

   to 
  which 
  I 
  beg 
  to 
  refer 
  readers 
  of 
  the 
  Philosophical 
  Magazine 
  

   who 
  take 
  an 
  interest 
  in 
  the 
  subject. 
  ■ 
  

  

  