﻿MAY 
  19, 
  1922 
  

  

  PROCeeDINGS 
  : 
  BIOLOGICAL 
  SOCIETY 
  

  

  251 
  

  

  1, 
  which 
  are 
  in 
  excellent 
  agreement 
  with 
  the 
  observed 
  distances, 
  

   are 
  the 
  result. 
  An 
  hypothesis 
  of 
  constant 
  atomic 
  dimensions 
  in 
  crys- 
  

   tals 
  which 
  is 
  based 
  on 
  the 
  most 
  reliable 
  data 
  meets, 
  however, 
  with 
  

   such 
  serious 
  difficulties 
  when 
  passing 
  from 
  compounds 
  of 
  one 
  type 
  to 
  

   those 
  of 
  another 
  that 
  it 
  can 
  scarcely 
  now 
  be 
  said 
  what 
  significance 
  

   attaches 
  to 
  such 
  numerical 
  agreements 
  as 
  this 
  one. 
  

  

  Crystal 
  

  

  LiF 
  

   LiCl 
  

  

  LiBr 
  

   Lil 
  

  

  NaF 
  

  

  NaCl 
  

  

  NaBr 
  

  

  Nal 
  

  

  KF 
  

   KCl 
  

   KBr 
  

   KI 
  

  

  RbF 
  

   RbCl 
  

   RbBr 
  

   Rbl 
  

  

  CsF 
  

   CsCl 
  

   CsBr 
  

   Csl 
  

  

  TABLE 
  1. 
  — 
  Summarized 
  Data 
  on 
  the 
  Alkali 
  Halides 
  

  

  structure 
  

  

  NaCl 
  (Fig. 
  1) 
  

   Body-centered 
  (Fig. 
  2) 
  

   Body-centered 
  (Fig. 
  2) 
  

   Body-centered 
  (Fig. 
  2) 
  

  

  Note: 
  The 
  distances 
  in 
  parentheses 
  are 
  used 
  to 
  calculate 
  the 
  values 
  in 
  the 
  last 
  column. 
  

  

  PROCEEDINGS 
  OF 
  THE 
  ACADEMY 
  AND 
  AFFILIATED 
  

  

  SOCIETIES 
  

  

  BIOLOGICAIv 
  SOCIETY 
  OF 
  WASHINGTON 
  

  

  629th 
  meeting 
  

  

  The 
  629th 
  meeting 
  of 
  the 
  Biological 
  Society 
  of 
  Washington, 
  was 
  held 
  

   jointly 
  with 
  Washington 
  Academy 
  of 
  Sciences 
  and 
  the 
  Botanical 
  Society 
  of 
  

   Washington 
  on 
  November 
  12, 
  1921 
  in 
  the 
  Lecture 
  Hall 
  of 
  the 
  Cosmos 
  Club 
  

   at 
  8: 
  00 
  o'clock 
  under 
  the 
  Presidency 
  of 
  the 
  Academy. 
  

  

  Prof. 
  Arthur 
  de 
  Jaczewski, 
  Director 
  of 
  the 
  Institute 
  of 
  Mycology 
  and 
  

   Pathology 
  at 
  Petrograd, 
  delivered 
  an 
  address 
  on 
  The 
  development 
  of 
  mycol- 
  

   ogy 
  and 
  pathology 
  in 
  Russia. 
  

  

  Prof. 
  Nicolas 
  I. 
  Vavilov, 
  Director 
  of 
  the 
  Bureau 
  of 
  Applied 
  Botany 
  and 
  

  

  