﻿[ 
  198 
  ] 
  

  

  XIY. 
  .Notices 
  respecting 
  New 
  Boohs. 
  

  

  The 
  Theory 
  of 
  Light 
  ; 
  a 
  Treatise 
  on 
  Physical 
  Optics. 
  By 
  Richard 
  

   C. 
  Maclaubin, 
  M.A., 
  LL.D. 
  In 
  three 
  parts, 
  Part 
  I. 
  Pp. 
  vii 
  

   + 
  326. 
  Cambridge 
  University 
  Press, 
  1908. 
  

  

  rpHERE 
  have 
  been 
  so 
  many 
  advanced 
  treatises 
  on 
  Physical 
  Optics 
  

   -*- 
  in 
  the 
  last 
  few 
  years 
  that 
  it 
  might 
  be 
  thought 
  superfluous 
  to 
  

   produce 
  another. 
  The 
  present 
  volume 
  is, 
  however, 
  of 
  so 
  singular 
  

   and 
  at 
  the 
  same 
  time 
  of 
  so 
  important 
  a 
  character 
  that 
  no 
  excuse 
  

   is 
  necessary 
  for 
  its 
  birth. 
  " 
  If 
  Theastetus, 
  you 
  have 
  a 
  wish 
  to 
  have 
  

   any 
  more 
  embryo 
  thoughts, 
  you 
  will 
  be 
  all 
  the 
  better 
  for 
  the 
  

   present 
  investigation, 
  and 
  if 
  not, 
  you 
  will 
  be 
  soberer 
  and 
  humbler 
  

   and 
  gentler 
  to 
  other 
  men, 
  not 
  fancying 
  that 
  you 
  know 
  what 
  you 
  

   do 
  not 
  know 
  " 
  (Plato). 
  Such 
  is 
  the 
  superscript 
  to 
  Chapter 
  I. 
  on 
  

   the 
  scope 
  and 
  method 
  of 
  the 
  enquiry, 
  in 
  which, 
  after 
  a 
  somewhat 
  

   metaphysical 
  discussion 
  on 
  the 
  chief 
  end 
  of 
  science 
  (which 
  seems 
  

   somewhat 
  remote 
  from 
  the 
  particular 
  subject 
  of 
  the 
  treatise), 
  he 
  

   decides 
  on 
  a 
  selection 
  of 
  the 
  Principle 
  of 
  Least 
  or 
  Stationary 
  

   Action 
  as 
  one 
  which 
  is 
  wide 
  enough 
  to 
  comprehend 
  the 
  whole 
  of 
  

   mechanical 
  science, 
  including 
  all 
  physics 
  in 
  that 
  sense, 
  and 
  the 
  

   aim 
  of 
  the 
  author 
  is 
  " 
  to 
  show 
  by 
  means 
  of 
  it 
  that 
  all 
  the 
  varied 
  and 
  

   complex 
  phenomena 
  of 
  physical 
  optics 
  may 
  be 
  woven 
  together 
  

   harmoniously 
  by 
  regarding 
  them 
  as 
  due 
  to 
  periodic 
  disturbances 
  

   in 
  a 
  medium 
  that 
  we 
  call 
  the 
  ether." 
  

  

  The 
  work 
  consists 
  of 
  much 
  that 
  is 
  common 
  to 
  other 
  treatises 
  on 
  

   Optics. 
  The 
  distinctive 
  feature 
  is 
  that 
  a 
  large 
  part 
  of 
  the 
  volume 
  

   embodies 
  in 
  a 
  modified 
  form 
  the 
  substance 
  of 
  a 
  series 
  of 
  papers 
  by 
  

   the 
  author 
  published 
  within 
  recent 
  years 
  by 
  the 
  Royal 
  Society. 
  

   These 
  deal 
  with 
  reflexion 
  and 
  refraction 
  by 
  transparent 
  crystals, 
  

   propagation 
  of 
  light 
  in 
  absorbing 
  isotropic 
  media, 
  Newton's 
  rings 
  

   formed 
  by 
  metallic 
  reflexion, 
  and 
  on 
  some 
  optical 
  properties 
  of 
  thin 
  

   metallic 
  plates, 
  together 
  with 
  other 
  kindred 
  topics. 
  

  

  We 
  may 
  observe 
  that 
  in 
  the 
  treatment 
  of 
  the 
  question 
  of 
  

   Newton's 
  rings, 
  the 
  author 
  perpetuates 
  the 
  time-honoured 
  method 
  

   of 
  developing 
  the 
  formula 
  from 
  the 
  case 
  of 
  parallel 
  plates. 
  

   Fringes 
  so 
  formed 
  are 
  strictly 
  speaking 
  attributable 
  to 
  Haidinger 
  

   and 
  not 
  to 
  Newton; 
  and 
  it 
  is 
  not 
  rigorously 
  correct 
  to 
  develop 
  the 
  

   formula 
  for 
  the 
  latter 
  from 
  the 
  case 
  of 
  parallel 
  plates. 
  It 
  would 
  

   give 
  an 
  erroneous 
  notion 
  of 
  the 
  book 
  if 
  we 
  were 
  to 
  lay 
  stress 
  on 
  a 
  

   small 
  consideration 
  like 
  this. 
  In 
  its 
  thoroughness 
  of 
  treatment 
  of 
  

   the 
  more 
  recondite 
  cases 
  of 
  interference 
  there 
  is 
  no 
  treatise 
  in 
  the 
  

   field 
  to 
  compete 
  with 
  it. 
  Not 
  the 
  least 
  merit 
  is 
  that 
  although 
  the 
  

   book 
  is 
  mathematical 
  in 
  nature 
  (actual 
  experiments 
  are 
  seldom 
  

   referred 
  to), 
  every 
  important 
  result 
  is 
  illustrated 
  by 
  curves 
  which 
  

   serve 
  to 
  reveal 
  the 
  nature 
  of 
  the 
  conclusions 
  which 
  would 
  be 
  

   hidden 
  from 
  many 
  readers 
  if 
  they 
  remained 
  merely 
  in 
  the 
  form 
  of 
  

   an 
  equation. 
  We 
  recommend 
  this 
  book 
  to 
  every 
  serious 
  student 
  in 
  

   physical 
  optics 
  who 
  has 
  previously 
  gained 
  familiarity 
  with 
  the 
  more 
  

   ordinan 
  experimental 
  phenomena 
  ami 
  theoretical 
  methods 
  from 
  

  

  