﻿to 
  — 
  WaW 
  T 
  > 
  

   in 
  the 
  general 
  case: 
  

  

  Theory 
  of 
  the 
  Thermoelectric 
  Forces. 
  787 
  

  

  a 
  , 
  = 
  i 
  Qi 
  2 
  

  

  Pi 
  P-2 
  

  

  Let 
  us 
  take 
  the 
  metals 
  copper 
  and 
  zinc. 
  The 
  thermal 
  

   conductivity 
  of 
  copper 
  ^: 
  2 
  = 
  0'94 
  cm. 
  gr. 
  sec. 
  cal.; 
  the 
  thermal 
  

   conductivity 
  of 
  zinc 
  ^ 
  = 
  0*26. 
  Let 
  us 
  consider 
  an 
  alloy 
  of 
  

   these 
  two 
  metals 
  containing 
  40 
  gr. 
  zinc 
  and 
  60 
  gr. 
  copper. 
  

   The 
  density 
  of 
  copper 
  being 
  8*8, 
  that 
  of 
  zinc 
  7*1, 
  we 
  shall 
  

   have 
  45 
  cm. 
  3 
  zinc 
  and 
  55 
  cm. 
  3 
  copper, 
  therefore 
  

  

  p 
  x 
  = 
  0*45, 
  jp 
  2 
  = 
  0\55, 
  

  

  p 
  1 
  0'4d 
  p 
  2 
  0*55 
  

  

  - 
  1 
  4- 
  -=2-29. 
  

  

  Pi 
  P2 
  

   The 
  Peltier 
  effect 
  between 
  copper 
  and 
  zinc 
  is 
  

  

  3^ 
  2 
  =l-62.10- 
  3 
  =Q 
  i; 
  Q 
  1 
  2 
  = 
  2-62.10- 
  6 
  ; 
  

  

  the 
  false 
  resistance 
  at 
  0° 
  C. 
  would 
  be 
  

  

  , 
  2-62. 
  1Q- 
  6 
  7 
  

  

  3.273.2-29 
  * 
  ' 
  

  

  co'= 
  5*9 
  . 
  10- 
  2 
  absolute 
  unit. 
  

   G^^.lO-^ohm. 
  

  

  The 
  electric 
  conductivity 
  of 
  copper 
  is 
  60 
  . 
  10 
  4 
  *, 
  its 
  specific 
  

  

  resistance 
  — 
  . 
  10~ 
  4 
  = 
  1'6 
  . 
  10~ 
  6 
  ; 
  the 
  electric 
  conductivity 
  of 
  

  

  zinc 
  is 
  16 
  . 
  10 
  4 
  per 
  cm. 
  3 
  , 
  its 
  specific 
  resistance 
  

  

  -^.10- 
  4 
  = 
  6-2.10- 
  6 
  . 
  

   16 
  

  

  If 
  the 
  resistance 
  of 
  the 
  alloy 
  copper 
  and 
  zinc 
  were 
  to 
  

   be 
  found 
  as 
  the 
  property 
  of 
  a 
  simple 
  mixture, 
  we 
  should 
  

   get: 
  

  

  (1-6 
  -55 
  + 
  45. 
  6-2) 
  . 
  1()6 
  = 
  3 
  . 
  6710 
  _ 
  g> 
  

  

  3F 
  2 
  

  

  