﻿228 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

  

  density 
  of 
  zinc 
  is 
  found 
  to 
  be 
  some 
  12 
  per 
  cent, 
  higher 
  when 
  in 
  an 
  

   atmosphere 
  of 
  argon 
  tban 
  in 
  one 
  of 
  nitrogen. 
  Such 
  facts 
  as 
  these 
  

   make 
  one 
  pause 
  contemplatively, 
  and 
  sympathise 
  more 
  completely 
  

   with 
  the 
  ideas 
  of 
  Lodge 
  expressed 
  on 
  p. 
  137 
  rather 
  than 
  with 
  the 
  

   main 
  ideas 
  underlying 
  this 
  volume. 
  

  

  Transactions 
  of 
  the 
  International 
  Union 
  for 
  Co-operation 
  in 
  Solar 
  

   Research, 
  Vol. 
  II. 
  Manchester 
  fniversity 
  Press. 
  

   This 
  volume, 
  which 
  is 
  edited 
  by 
  Prof. 
  A. 
  Schuster, 
  contains 
  the 
  

   verbatim 
  report 
  of 
  the 
  Third 
  Conference 
  of 
  the 
  International 
  

   Union 
  held 
  at 
  Meudon 
  in 
  1907. 
  Amongst 
  the 
  papers 
  communi- 
  

   cated 
  and 
  printed 
  here 
  are 
  one 
  on 
  the 
  determination 
  of 
  the 
  wave- 
  

   length 
  of 
  the 
  red 
  ray 
  of 
  cadmium 
  as 
  a 
  fundamental 
  standard 
  of 
  

   wave-lengths 
  by 
  MM. 
  Benoit, 
  Fabry 
  and 
  Perot; 
  the 
  work 
  of 
  

   MM. 
  Pabry 
  and 
  Buisson 
  on 
  measurements 
  of 
  wave-lengths 
  made 
  

   to 
  establish 
  a 
  system 
  of 
  spectroscopic 
  standards 
  ; 
  the 
  measurement 
  

   of 
  Solar 
  Photographs 
  made 
  with 
  the 
  spectroheliograph 
  by 
  Greorge 
  

   E. 
  Hale 
  ; 
  and 
  the 
  report 
  of 
  the 
  Committee 
  on 
  Sun-spot 
  spectra 
  

   drawn 
  up 
  by 
  the 
  Secretary 
  (A. 
  Fowler), 
  including 
  a 
  list 
  of 
  publi- 
  

   cations 
  referring 
  to 
  Sun-spot 
  spectra. 
  The 
  volume 
  is 
  crowded 
  

   with 
  interesting 
  and 
  valuable 
  matter. 
  

  

  XXVI. 
  Intelligence 
  and 
  Miscellaneous 
  Articles. 
  

   To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

   Gentlemen, 
  — 
  

  

  TN 
  a 
  paper 
  of 
  April 
  1909 
  in 
  this 
  Magazine, 
  the 
  Earl 
  of 
  Berkeley 
  

   -*- 
  and 
  C. 
  V. 
  Burton 
  treat 
  the 
  problem 
  of 
  finding 
  the 
  influence 
  of 
  

   gravity 
  upon 
  a 
  binary 
  solution. 
  I 
  wish 
  to 
  call 
  the 
  attention 
  of 
  

   the 
  authors 
  to 
  the 
  fact, 
  which 
  they 
  seem 
  to 
  have 
  overlooked, 
  that 
  

   a 
  complete 
  solution 
  of 
  the 
  problem 
  is 
  to 
  be 
  found 
  in 
  a 
  paper 
  * 
  by 
  

   the 
  writer 
  pubhshed 
  Oct. 
  1906. 
  The 
  cases 
  of 
  a 
  rotating 
  solution 
  

   and 
  a 
  solution 
  subject 
  to 
  the 
  earth's 
  field 
  were 
  specially 
  treated, 
  

   and 
  in 
  the 
  latter 
  case 
  numerical 
  calculations 
  were 
  carried 
  out 
  for 
  

   solutions 
  of 
  cane-sugar 
  and 
  potassium 
  hydrate. 
  Further, 
  the 
  

   following 
  equation 
  was 
  found: 
  — 
  

  

  /^ttX 
  dc 
  1 
  ^TT 
  

  

  This 
  important 
  relation 
  connecting 
  the 
  concentration 
  gradient 
  

   with 
  the 
  variation 
  of 
  osmotic 
  pressure 
  with 
  hydrostatic 
  pressure 
  

   is 
  identical 
  with 
  the 
  relation 
  expressed 
  in 
  equation 
  (7) 
  in 
  their 
  

   paper. 
  

  

  I 
  am, 
  Gi-entlemen, 
  

  

  Yours 
  faithfully, 
  

  

  L. 
  Vegaed. 
  

  

  * 
  Christiania 
  Vid. 
  Selsk. 
  Skr. 
  No. 
  8, 
  1906 
  ; 
  Phil. 
  Mag. 
  May 
  1907. 
  

  

  