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  Browx: 
  The 
  refraction 
  of 
  light 
  in 
  plant 
  tissues 
  

  

  TABLE 
  I 
  

  

  A 
  Series 
  of 
  Refractive 
  Oils 
  used 
  in 
  the 
  Determixation 
  of 
  Relative 
  

  

  Refraction" 
  

  

  The 
  tesUiquids 
  are 
  made 
  from 
  mixtures 
  of 
  naphthalene 
  a 
  monobromated 
  (naphth.) 
  

   clove 
  oil 
  (clove), 
  and 
  castor 
  oil 
  (cast.), 
  and 
  are 
  arranged 
  in 
  sequence 
  according 
  to 
  

   refraction. 
  O 
  indicates 
  in 
  what 
  media 
  the 
  outlines 
  are 
  invisible 
  or 
  nearly 
  so; 
  + 
  

   or 
  — 
  » 
  that 
  the 
  refraction 
  is 
  either 
  more 
  or 
  less 
  than 
  that 
  of 
  the 
  liquid. 
  

  

  Test 
  liquids 
  

  

  Lignified 
  and 
  furfurol-reacting 
  

  

  tissues 
  

  

  Pectin, 
  cellulose 
  

  

  tissues 
  

  

  Cell 
  contents 
  

  

  second 
  is 
  correspondingly 
  increased 
  (o, 
  i, 
  2, 
  . 
  . 
  . 
  10), 
  or 
  in 
  such 
  a 
  

  

  two 
  

  

  be 
  

  

  i 
  

  

  tures 
  will 
  form 
  a 
  gradient 
  series 
  (see 
  Table 
  I). 
  In 
  order 
  to 
  

  

  between 
  

  

  necessary 
  

  

  by 
  which 
  the 
  relative 
  volumes 
  are 
  consecutively 
  changed. 
  

  

  To 
  measure 
  the 
  volumes, 
  a 
  medicine 
  dropper 
  may 
  be 
  used, 
  

   but 
  allowance 
  must 
  be 
  made 
  for 
  the 
  rplntN/*^ 
  c;,^ 
  ^.f 
  ^ 
  a 
  — 
  : 
  t. 
  

  

  