﻿8(J0 
  Prof. 
  Skinner 
  and 
  Mr. 
  Tool 
  on 
  the 
  Optical 
  

  

  Table 
  XVIII.— 
  Electrolytic 
  Nickel. 
  

  

  Thickness 
  : 
  No. 
  -40, 
  71 
  x 
  10~ 
  7 
  cm. 
  (meas.) 
  ; 
  

   Xo. 
  41, 
  37-4 
  x 
  10 
  -7 
  cm. 
  (calc). 
  

  

  

  Field 
  : 
  13.800 
  C.G.S. 
  

  

  

  

  

  

  

  No. 
  4u. 
  

  

  

  No. 
  41. 
  

  

  

  

  Wave- 
  

   length. 
  

  

  

  

  

  

  

  Rnt 
  R 
  ° 
  tat 
  -Xl0- 
  5 
  Elh 
  V 
  U 
  

   lv 
  " 
  L 
  Thick. 
  X1U 
  ' 
  Xl& 
  

  

  Rot. 
  

  

  — 
  tat 
  -xl0- 
  5 
  

   Thick. 
  XU 
  ' 
  

  

  Ellipt. 
  

  

  xlo 
  s 
  . 
  

  

  X 
  io~ 
  6 
  . 
  

  

  440 
  

  

  •74 
  1-04 
  

  

  •41 
  

  

  M0 
  

  

  

  

  4*0 
  

  

  •85 
  120 
  

  

  •42 
  

  

  1-12 
  

  

  97 
  

  

  182 
  

  

  520 
  

  

  •90 
  127 
  127 
  

  

  •+< 
  

  

  1-27 
  

  

  9-2 
  

  

  182 
  

  

  560 
  

  

  •99 
  1 
  39 
  

  

  •50 
  

  

  1-34 
  

  

  9-0 
  

  

  183 
  

  

  600 
  

  

  1-07 
  i:>i 
  

  

  •56 
  

  

  1-48 
  ; 
  

  

  S-9 
  

  

  1-84 
  

  

  630 
  

  

  

  01 
  

  

  105 
  

  

  9-0 
  

  

  

  (IK) 
  

  

  

  

  

  

  

  1-87 
  

  

  reliable 
  because 
  this 
  ratio 
  is 
  practically 
  the 
  same 
  for 
  all 
  

   colours. 
  The 
  ellipticity 
  is 
  evidently 
  not 
  proportional 
  to 
  the 
  

   thickness, 
  shown 
  by 
  comparing 
  the 
  values 
  obtained 
  from 
  the 
  

   two 
  films 
  at 
  a 
  wave-length 
  of 
  520 
  ja/j,. 
  A 
  third 
  film 
  (No. 
  42) 
  

   was 
  deposited 
  somewhat 
  differently 
  from 
  the 
  others 
  and 
  tested 
  

   for 
  magnetic 
  rotation 
  and 
  ellipticity. 
  The 
  results 
  are 
  found 
  

   in 
  Table 
  XIX. 
  The 
  thickness 
  measured 
  was 
  35xl0~ 
  7 
  cm. 
  

   It 
  may 
  be 
  noted 
  by 
  comparison 
  with 
  film 
  No. 
  41 
  of 
  the 
  

   preceding 
  table 
  that 
  while 
  the 
  rotation 
  of 
  42 
  is 
  greater 
  than 
  

   that 
  of 
  41. 
  its 
  ellipticity 
  18 
  somewhat 
  -mailer. 
  A 
  more 
  

   striking 
  difference 
  is 
  observed 
  on 
  comparing 
  the 
  rotatory 
  

   power 
  of 
  the 
  two 
  films. 
  No. 
  42 
  exhibits 
  on 
  the 
  average 
  fifty 
  

  

  Table 
  XIX. 
  — 
  Electrolytic 
  Nickel. 
  

   Thickness, 
  35 
  xl(>- 
  ; 
  cm. 
  (meas.). 
  Field, 
  13,800 
  c.G.s. 
  

  

  Wave- 
  

   length. 
  

  

  Rotation 
  

   (deg.). 
  

  

  Rotation 
  _ 
  § 
  

   Thickness 
  

  

  Ellipticity 
  

   XlO 
  a 
  . 
  

  

  440 
  

  

  •52 
  

  

  150 
  

  

  91 
  

  

  480 
  

  

  •57 
  

  

  1-04 
  

  

  86 
  

  

  520 
  

  

  ■i)D 
  

  

  157 
  

  

  8-9 
  

  

  560 
  

  

  •63 
  

  

  1-80 
  

  

  8-8 
  

  

  600 
  

  

  •72 
  

  

  2-06 
  

  

  92 
  

  

  630 
  

  

  r. 
  

  

  2 
  23 
  

  

  

  