﻿246 
  

  

  Dr. 
  J. 
  C 
  Beattie 
  on 
  the 
  Electric 
  Resistance 
  

  

  then 
  the 
  variation 
  of 
  resistance, 
  The 
  order 
  in 
  which 
  the 
  

   two 
  are 
  measured 
  affects 
  the 
  result 
  in 
  the 
  case 
  of 
  nickel 
  ; 
  in 
  

   that 
  metal 
  there 
  is 
  a 
  hysteresis 
  effect 
  in 
  both 
  phenomena. 
  

   In 
  cobalt 
  the 
  hysteresis 
  effect 
  is 
  so 
  small 
  as 
  to 
  be 
  negligible. 
  

  

  To 
  discover 
  whether 
  or 
  not 
  the 
  resistance 
  of 
  the 
  platinized 
  

   glass 
  and 
  the 
  connecting 
  wires 
  was 
  modified 
  by 
  the 
  presence 
  

   of 
  the 
  magnetic 
  field, 
  a 
  nickel 
  film 
  was 
  first 
  used 
  ; 
  its 
  

   variation 
  of 
  resistance 
  was 
  observed 
  and 
  the 
  nickel 
  afterwards 
  

   taken 
  off 
  by 
  means 
  of 
  acid 
  ; 
  the 
  platinum 
  mirror 
  and 
  its 
  

   connecting 
  wires 
  showed 
  no 
  change 
  of 
  resistance 
  due 
  to 
  the 
  

   creation 
  of 
  the 
  magnetic 
  field. 
  

  

  Cobalt. 
  

  

  The 
  following 
  are 
  some 
  of 
  the 
  results 
  obtained 
  with 
  cobalt 
  

   films 
  : 
  — 
  

  

  No. 
  XXIII. 
  — 
  Resistance 
  between 
  primary 
  electrodes 
  2*492 
  XI. 
  

   Primary 
  current 
  - 
  5 
  ^q 
  amp. 
  (8| 
  x 
  13^ 
  mm.) 
  

  

  Field 
  in 
  

  

  Hall 
  effect. 
  

  

  • 
  

  

  Variation 
  of 
  

  

  Hall 
  effect 
  

  

  E.-E 
  

  

  C.G.S. 
  units. 
  

  

  i 
  

  

  resistance. 
  

  

  

  

  V 
  variation. 
  

  

  K 
  

  

  2,400 
  

  

  37-75 
  

  

  -13-75 
  

  

  10-2 
  

  

  -0 
  0003644 
  

  

  5,100 
  

  

  58-00 
  

  

  -35-0 
  

  

  10-2 
  

  

  -0 
  0009275 
  

  

  6,600 
  

  

  85-75 
  

  

  -66-25 
  

  

  10-5 
  

  

  -0C01756 
  

  

  8,500 
  

  

  11775 
  

  

  -130 
  5 
  

  

  10-3 
  

  

  -0 
  002458 
  

  

  10,300 
  

  

  135-75 
  

  

  -179 
  

  

  101 
  

  

  -0 
  004744 
  

  

  11,700 
  

  

  154-5 
  

  

  -229-5 
  

  

  10-2 
  

  

  -0 
  006082 
  

  

  13,800 
  

  

  163-75 
  

  

  -2430 
  

  

  105 
  

  

  -0-006440 
  

  

  16.160 
  

  

  168-00 
  

  

  -256 
  5 
  

  

  10 
  5 
  

   10-3 
  

  

  -00C6796 
  

  

  No. 
  XXY1. 
  — 
  Resistance 
  between 
  primary 
  electrodes 
  2*019 
  12. 
  

   Primary 
  current 
  ^ 
  amp. 
  (9| 
  x 
  1\ 
  mm.) 
  

  

  Field 
  in 
  

   C.G.S. 
  units. 
  

  

  Hall 
  effect. 
  

  

  Variation 
  of 
  

   resistance. 
  

  

  Hall 
  effect 
  

  

  R 
  

  

  V 
  variation. 
  

  

  4,300 
  

  

  5,400 
  

  

  8,520 
  

   10,300 
  

   11,700 
  

   13,800 
  

   16,160 
  

  

  . 
  

  

  4625 
  

   73-0 
  

   114-5 
  

   135-25 
  

   1670 
  

   183-5 
  

   188-0 
  

  

  -190 
  

   -34-5 
  

   -104 
  

   -13575 
  

   -183-5 
  

   -2080 
  

   -225 
  

  

  110 
  

   123 
  

   11-2 
  

   11-6 
  

   129 
  

   12-6 
  

   12-5 
  

  

  120 
  

  

  -0 
  000699 
  

   -0 
  001269 
  

   -0003827 
  

   -0004968 
  

   -0-006726 
  

   -0007654 
  

   -0008290 
  

  

  