﻿508 
  L. 
  Page— 
  The 
  Photoelectric 
  Effect. 
  

  

  (2) 
  The 
  maximum 
  energies 
  satisfy 
  Einstein's 
  equation, 
  

   L 
  = 
  hv 
  — 
  P 
  provided 
  a 
  somewhat 
  smaller 
  value 
  of 
  h 
  is 
  used 
  

   than 
  that 
  usually 
  attributed 
  to 
  the 
  radiation 
  constant. 
  This 
  

   is 
  equally 
  true 
  of 
  scraped 
  and 
  unscraped 
  metals. 
  

  

  (3) 
  The 
  shift 
  of 
  the 
  saturation 
  point 
  (the 
  true 
  zero 
  potential) 
  

   in 
  the 
  direction 
  of 
  increasing 
  electropositiveness 
  after 
  scraping 
  

   in 
  vacuum 
  indicates 
  that 
  the 
  contact 
  difference 
  of 
  potential 
  can- 
  

   not 
  be 
  due 
  essentially 
  to 
  a 
  double 
  layer 
  on 
  the 
  surface 
  of 
  the 
  

   metal. 
  

  

  The 
  author 
  wishes 
  to 
  acknowledge 
  his 
  indebtedness 
  to 
  Pro- 
  

   fessor 
  Bumstead 
  for 
  suggesting 
  the 
  subject 
  of 
  this 
  investi- 
  

   gation, 
  and 
  to 
  Professors 
  Bumstead 
  and 
  Boltwood 
  for 
  the 
  

   suggestions 
  they 
  have 
  offered 
  and 
  help 
  they 
  have 
  given. 
  

  

  Sloane 
  Physical 
  Laboratory, 
  

   Yale 
  University. 
  

  

  