﻿194 
  temperature 
  Variation 
  of 
  Nickel 
  and 
  Iron. 
  

  

  Peltier 
  Coefficients. 
  

  

  T 
  dE 
  

  

  ' 
  dt 
  ' 
  

  

  Temperature. 
  

  

  Note. 
  

  

  Copper-Iron. 
  

   +1156 
  

  

  -191-2 
  

  

  Liquid 
  air. 
  

  

  Copper-Nickel. 
  

   -7697 
  

  

  -191-2 
  

  

  Liquid 
  air. 
  

  

  A 
  Comparison 
  with 
  Fleming's 
  Results 
  for 
  Iron, 
  Copper, 
  

   and 
  Nickel- 
  Copper. 
  

  

  

  Present 
  Experiments. 
  

  

  Fleming 
  and 
  Dewar's. 
  

  

  E.M.F. 
  in 
  microvolts. 
  

  

  - 
  

  

  E.M.F. 
  in 
  microvolts. 
  

  

  Cop 
  per- 
  Nickel. 
  

   Liquid 
  air. 
  

   100° 
  C. 
  

  

  -2907 
  

   2233 
  

  

  -2380 
  

   2205 
  

  

  Copper- 
  Iron. 
  

   Liquid 
  air. 
  

   100° 
  C. 
  

  

  -2191 
  

  

  870 
  

  

  -2589 
  

   1138 
  

  

  Nickel 
  -Iron. 
  

   Liquid 
  air. 
  

  

  -5111 
  

  

  -4969 
  

  

  The 
  main 
  object 
  of 
  the 
  present 
  research 
  was 
  originally 
  to 
  

   correlate 
  the 
  peculiar 
  thermoelectric 
  points 
  with 
  the 
  changes 
  

   of 
  slope 
  on 
  the 
  resistance-curves. 
  

  

  The 
  result 
  from 
  this 
  point 
  of 
  view 
  is 
  that 
  the 
  thermoelectric 
  

   change 
  in 
  nickel-copper 
  coincides 
  approximately 
  with 
  the 
  

   resistance 
  change, 
  but 
  that 
  no 
  theremoelectric 
  peculiarity 
  

   exists 
  for 
  iron-copper 
  at 
  the 
  temperature 
  of 
  the 
  Fe 
  resistance 
  

   change. 
  As 
  is 
  shown 
  by 
  the 
  Peltier 
  coefficients, 
  a 
  marked 
  

   change 
  occurs 
  at 
  about 
  500° 
  in 
  the 
  case 
  of 
  Fe-Cu. 
  This 
  is 
  

   approximately 
  the 
  temperature 
  at 
  which 
  a 
  flexure 
  occurs 
  in 
  

   the 
  copper 
  resistance-curve. 
  

  

  