﻿460 
  JOURNAL 
  OF 
  THE 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  20 
  

  

  allied 
  only 
  to 
  C. 
  duhia. 
  From 
  that 
  it 
  differs 
  in 
  having 
  the 
  receptacle 
  nearer 
  

   the 
  margin, 
  the 
  marginal 
  lobule 
  regularly 
  though 
  not 
  deeply 
  concave 
  (not 
  

   recurved 
  or 
  reflexed, 
  as 
  in 
  C. 
  dubia) 
  and 
  approaching 
  somewhat 
  the 
  "ac- 
  

   cessory 
  indusium" 
  form 
  of 
  typical 
  Culcita, 
  and 
  the 
  true 
  indusium 
  larger 
  and 
  

   more 
  freely 
  long-ciliate. 
  The 
  specimen 
  selected 
  as 
  the 
  type 
  is 
  very 
  incom- 
  

   plete, 
  and 
  the 
  measurements 
  are 
  thus 
  not 
  dependable. 
  As 
  noted 
  previously 
  

   this 
  is 
  doubtless 
  the 
  plant 
  listed 
  by 
  Luerssen 
  as 
  Dicksonia 
  dubia 
  on 
  Fiji 
  

   specimens 
  collected 
  by 
  Graeffe 
  (nos. 
  151, 
  490) 
  and 
  Darnel 
  (nos. 
  31, 
  32). 
  

  

  PROCEEDINGS 
  OF 
  THE 
  ACADEMY 
  AND 
  AFFILIATED 
  

  

  SOCIETIES 
  

  

  PHILOSOPHICAL 
  SOCIETY 
  OF 
  WASHINGTON 
  

  

  867th 
  MEETING 
  

  

  The 
  867th 
  meeting 
  was 
  held 
  in 
  the 
  Cosmos 
  Club 
  auditorium 
  Saturday, 
  

   May 
  20, 
  1922, 
  with 
  President 
  Crittenden 
  in 
  the 
  chair 
  and 
  42 
  persons 
  present. 
  

  

  R. 
  C. 
  Tolman: 
  Some 
  remarks 
  on 
  the 
  Quantum 
  Theory. 
  This 
  paper 
  was 
  

   illustrated 
  by 
  charts 
  and 
  figures, 
  and 
  was 
  discussed 
  by 
  Messrs. 
  Beal, 
  C. 
  A. 
  

   Briggs, 
  Fairchild, 
  Foote, 
  Hawkesworth, 
  Mohler, 
  Pawling, 
  Sosman, 
  

   Tuckerman, 
  Wells 
  and 
  White. 
  This 
  paper 
  has 
  been 
  published 
  in 
  full 
  in 
  

   1922, 
  number 
  of 
  the 
  Journal 
  of 
  the 
  Optical 
  Society. 
  

  

  The 
  speaker 
  first 
  reviewed 
  the 
  steps 
  by 
  which 
  the 
  Classical 
  Dynamics 
  

   was 
  led 
  to 
  expect 
  that 
  there 
  would 
  be 
  an 
  equipartition 
  of 
  energy 
  between 
  

   the 
  different 
  modes 
  of 
  vibration 
  in 
  the 
  hohlraum. 
  The 
  modifications 
  in 
  

   the 
  Classical 
  Dynamics 
  which 
  are 
  proposed 
  by 
  Quantum 
  Theory 
  to 
  meet 
  

   the 
  contradiction 
  between 
  this 
  prediction 
  of 
  the 
  Classical 
  D5aiamics 
  and 
  

   the 
  experimental 
  facts 
  were 
  then 
  discussed. 
  

  

  The 
  equations 
  given 
  by 
  Quantum 
  Theory 
  for 
  the 
  possible 
  steady 
  motions 
  

   of 
  simple 
  oscillators 
  and 
  rotators 
  and 
  for 
  the 
  distribution 
  of 
  elements 
  at 
  thermo- 
  

   dynamic 
  equilibrium 
  were 
  then 
  developed. 
  It 
  was 
  shown 
  how 
  these 
  equa- 
  

   tions 
  account 
  for 
  the 
  photoelectric 
  effect, 
  the 
  inverse 
  photoelectric 
  effect, 
  

   the 
  relation 
  between 
  the 
  frequenceis 
  of 
  absorbed 
  and 
  phosphorescent 
  light, 
  

   the 
  energy 
  distribution 
  in 
  the 
  hohlraum, 
  the 
  Debye 
  theory 
  of 
  the 
  specific 
  

   heat 
  of 
  solids, 
  the 
  theory 
  of 
  rotational 
  specific 
  heat 
  of 
  gases, 
  the 
  theory 
  of 
  

   the 
  rotational 
  spectra 
  of 
  gases, 
  and 
  the 
  theory 
  of 
  the 
  emission 
  spectra 
  of 
  

   the 
  elements. 
  

  

  The 
  Quantum 
  Theory 
  was 
  then 
  criticised 
  from 
  the 
  point 
  of 
  view 
  of 
  its 
  

   arbitrariness, 
  its 
  conflict 
  with 
  the 
  facts 
  concerning 
  the 
  undulatory 
  nature 
  of 
  

   light, 
  its 
  apparently 
  unnecessary 
  abandonment 
  of 
  the 
  Classical 
  Dynamics 
  

   in 
  solving 
  the 
  problem 
  of 
  the 
  distribution 
  of 
  energy 
  in 
  the 
  hohlraum 
  and 
  the 
  

   unsatisfactoriness 
  of 
  its 
  atomic 
  model. 
  A 
  model 
  which 
  contains 
  some 
  fea- 
  

   tures 
  which 
  it 
  might 
  be 
  desirable 
  to 
  incorporate 
  in 
  the 
  final 
  model 
  of 
  the 
  

   hydrogen 
  atom 
  was 
  then 
  exhibited. 
  

  

  W. 
  R. 
  Gregg, 
  Recording 
  Secretary, 
  Pro 
  Tern. 
  

  

  869th 
  meeting 
  

  

  The 
  869th 
  meeting 
  was 
  held 
  in 
  the 
  Cosmos 
  Club 
  auditorium 
  Saturday, 
  

   October 
  7, 
  1922. 
  

  

  