﻿Effect 
  of 
  Magnetic 
  Field 
  on 
  Metallic 
  Resistance. 
  353 
  

  

  5. 
  The 
  arithmetical 
  series 
  which 
  connects 
  the 
  frequencies 
  

   in 
  the 
  first 
  group 
  of 
  bands 
  is 
  not 
  merely 
  similar 
  to, 
  but 
  

   identical 
  with, 
  that 
  found 
  by 
  Deslandres 
  for 
  the 
  second 
  group, 
  

   and 
  it 
  begins 
  almost 
  exactly 
  where 
  the 
  other 
  leaves 
  off. 
  

  

  If 
  these 
  facts 
  are 
  sufficient 
  to 
  show 
  that 
  the 
  arrangement 
  

   given 
  above 
  is 
  a 
  real 
  one, 
  there 
  are 
  several 
  points 
  of 
  interest 
  

   to 
  be 
  noticed 
  in 
  it. 
  

  

  (1) 
  The 
  true 
  breadth 
  of 
  a 
  band 
  seems 
  to 
  be 
  the 
  interval 
  

   of 
  frequency 
  between 
  the 
  strongest 
  line 
  in 
  the 
  head 
  and 
  the 
  

   corresponding 
  line 
  in 
  the 
  head 
  of 
  the 
  next 
  consecutive 
  band 
  

   of 
  that 
  series 
  (not 
  the 
  next 
  numerically 
  consecutive 
  band, 
  

   e.g. 
  15096 
  to 
  16627, 
  and 
  not 
  15096 
  to 
  15278) 
  ; 
  for 
  it 
  is 
  only 
  

   by 
  classifying 
  the 
  bands 
  on 
  this 
  system 
  that 
  we 
  discover 
  the 
  

   law 
  of 
  their 
  distribution. 
  

  

  (2) 
  As 
  a 
  rule 
  the 
  visible 
  portion 
  of 
  the 
  band 
  is 
  confined 
  to 
  

   the 
  first 
  eighth 
  or 
  tenth 
  of 
  its 
  brea 
  1th. 
  

  

  (3) 
  The 
  breadth 
  of 
  the 
  bands 
  in 
  each 
  series 
  of 
  the 
  first 
  

   group 
  decreases 
  as 
  the 
  frequency 
  increases, 
  while 
  in 
  the 
  

   second 
  group, 
  of 
  which 
  the 
  law 
  was 
  found 
  by 
  Deslandres, 
  the 
  

   breadth 
  increases 
  as 
  the 
  frequency 
  increases. 
  This 
  fact, 
  as 
  

   interesting 
  as 
  it 
  was 
  unexpected, 
  seems 
  to 
  offer 
  a 
  clue 
  to 
  

   the 
  cause 
  of 
  the 
  banded 
  spectrum. 
  

  

  (4) 
  The 
  arrangement 
  of 
  the 
  bright 
  lines 
  in 
  a 
  band 
  of 
  the 
  

   first 
  group 
  differs 
  slightly 
  from 
  that 
  of 
  those 
  in 
  a 
  band 
  of 
  

   the 
  second 
  group. 
  In 
  the 
  former 
  the 
  lines 
  are 
  comparatively 
  

   few 
  and 
  the 
  three 
  lines 
  forming 
  the 
  head 
  are 
  widely 
  separated. 
  

   In 
  the 
  latter 
  the 
  lines 
  are 
  numerous 
  and 
  run 
  in 
  triplets, 
  

   and 
  the 
  three 
  lines 
  forming 
  the 
  head 
  are 
  close 
  together. 
  

   As 
  the 
  bands 
  also 
  differ 
  in 
  the 
  circumstance 
  mentioned 
  

   above 
  (3), 
  it 
  is 
  possible 
  that 
  these 
  two 
  results 
  are 
  both 
  due 
  

   to 
  the 
  same 
  cause. 
  

  

  (5) 
  The 
  bands 
  in 
  each 
  series 
  seem 
  to 
  be 
  related 
  like 
  the 
  

   notes 
  in 
  a 
  scale, 
  while 
  the 
  series 
  may 
  be 
  compared 
  to 
  the 
  same 
  

   scale 
  in 
  different 
  keys. 
  

  

  XXXVII. 
  On 
  the 
  Effect 
  of 
  a 
  Transverse 
  Magnetic 
  Field 
  on 
  

   Metallic 
  Resistance. 
  

  

  Cavendish 
  Laboratory, 
  Cambridge, 
  

   February 
  12, 
  1902. 
  

  

  To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

   Gentlemen, 
  

  

  IN 
  ' 
  Communications 
  from 
  the 
  Physical 
  Laboratory 
  of 
  

   Leiden,' 
  No. 
  72, 
  Dr. 
  E. 
  vanEverdingen 
  gives 
  an 
  investi- 
  

   gation 
  of 
  the 
  effect 
  of 
  magnetic 
  force 
  on 
  the 
  resistance 
  of 
  

   Phil. 
  Mag. 
  S. 
  6. 
  Vol. 
  3. 
  No. 
  15. 
  March 
  1902. 
  2 
  A 
  

  

  