﻿THE 
  

   LONDON, 
  EDINBURGH, 
  and 
  DUBLIN 
  

  

  PHILOSOPHICAL 
  MAGAZINE 
  

  

  AND 
  

  

  JOURNAL 
  OF 
  SCIENCE. 
  

  

  [SIXTH 
  SERIES.]//,- 
  c/ 
  

  

  JUNE 
  1918. 
  

  

  LIII. 
  Molecular 
  Frequency 
  and 
  Molecular 
  JS 
  umber. 
  — 
  Pai 
  t 
  III. 
  

   Inorganic 
  Compounds. 
  Lindemann's 
  Formula, 
  By 
  H. 
  

   Stanley 
  Allen, 
  M.A 
  , 
  D.Sc, 
  University 
  of 
  London, 
  

   King's 
  College*. 
  

  

  IN 
  the 
  present 
  communication 
  are 
  given 
  the 
  values 
  of 
  the 
  

   characteristic 
  molecular 
  frequency, 
  v, 
  Calculated 
  by 
  

   Lindemann's 
  formula 
  for 
  those 
  inorganic 
  compounds 
  for 
  

   which 
  data 
  are 
  available. 
  The 
  formula 
  in 
  question 
  may 
  be 
  

   written 
  

  

  ,S 
  V(&> 
  

  

  where 
  T 
  s 
  is 
  the 
  absolute 
  temperature 
  of 
  the 
  melting-point, 
  

   M 
  is 
  the 
  molecular 
  weight, 
  and 
  V 
  the 
  molecular 
  volume. 
  

   The 
  coefficient 
  k 
  has 
  been 
  assumed 
  constant, 
  and 
  Nernst's 
  

   empirical 
  value, 
  3*08 
  X 
  10 
  12 
  , 
  has 
  been 
  employed. 
  

  

  For 
  each 
  compound 
  is 
  tabulated 
  the 
  value 
  of 
  the 
  molecular 
  

   number, 
  N, 
  and 
  of 
  the 
  product 
  ±svX 
  10~ 
  12 
  . 
  In 
  the 
  majority 
  

   of 
  cases 
  it 
  has 
  been 
  found 
  possible 
  to 
  express 
  Nj> 
  either 
  in 
  the 
  

   form 
  ,iv 
  A 
  or 
  in 
  the 
  form 
  (n 
  + 
  J) 
  v 
  A) 
  where 
  n 
  is 
  an 
  integer 
  and 
  v 
  x 
  

   is 
  a 
  constant 
  frequency 
  having 
  a 
  value 
  about 
  21 
  x 
  10 
  12 
  sec. 
  -1 
  . 
  

   In 
  the 
  few 
  exceptional 
  cases 
  where 
  neither 
  of 
  the 
  above 
  forms 
  

   is 
  applicable 
  the 
  product 
  has 
  been 
  expressed 
  as 
  (n-\-^)v 
  A 
  or 
  

   (n 
  + 
  j 
  i> 
  A 
  , 
  but 
  no 
  special 
  significance 
  is 
  at 
  present 
  attached 
  

   to 
  such 
  results. 
  All 
  the 
  results 
  here 
  given 
  must 
  be 
  con- 
  

   sidered 
  in 
  the 
  light 
  of 
  the 
  general 
  considerations 
  affecting 
  

   Lindemann's 
  formula 
  put 
  forward 
  in 
  Part 
  I. 
  of 
  this 
  paper*. 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

  

  t 
  Phil. 
  Mag. 
  vol. 
  xxxv. 
  p. 
  338, 
  April 
  1918. 
  

  

  Phil. 
  Mag. 
  S. 
  6, 
  Vol. 
  35. 
  No. 
  210. 
  June 
  1918. 
  2 
  I 
  

  

  