﻿Phythmic 
  Precipitation. 
  

  

  V6 
  

  

  the 
  development 
  of 
  one 
  of 
  these 
  bands 
  under 
  the 
  microscope 
  

   it 
  was 
  seen 
  that 
  the 
  very 
  numerous 
  small 
  granules 
  were 
  devel- 
  

   oped 
  apparently 
  independently 
  of 
  each 
  other. 
  The 
  band 
  grew 
  

   quite 
  slowly, 
  being 
  extended 
  laterally. 
  As 
  it 
  developed 
  the 
  

   central 
  part 
  extended 
  itself 
  in 
  advance 
  of 
  the 
  two 
  sides, 
  and 
  

  

  Fig. 
  3. 
  

  

  Fig. 
  3. 
  x 
  5. 
  The 
  result 
  of 
  the 
  diffusion 
  of 
  8N 
  silver 
  nitrate 
  into 
  a 
  gelatine 
  

   containing 
  N/60 
  potassium 
  chromate. 
  It 
  shows 
  the 
  close 
  bands 
  (apparently 
  

   a 
  continuous 
  mass 
  of 
  precipitate) 
  passing 
  outward 
  into 
  separated 
  bands, 
  

   which 
  are 
  broken 
  toward 
  the 
  outside, 
  and 
  surrounded 
  by 
  a 
  zone 
  of 
  ' 
  ' 
  granu- 
  

   lar 
  " 
  precipitate 
  and 
  then 
  by 
  a 
  clear 
  " 
  halo." 
  The 
  bands 
  are 
  broken 
  by 
  sev- 
  

   eral 
  clear 
  channels. 
  The 
  bands 
  on 
  opposite 
  sides 
  of 
  these 
  are 
  not 
  directly 
  

   opposite 
  to 
  each 
  other, 
  and 
  they 
  bend 
  inwards 
  toward 
  the 
  drop 
  from 
  which 
  

   the 
  diffusion 
  took 
  place. 
  These 
  may 
  be 
  explained 
  by 
  uneven 
  distributions 
  

   of 
  concentrations 
  of 
  chromate 
  or 
  silver 
  ions, 
  or 
  of 
  both! 
  

  

  these 
  followed, 
  sometimes 
  more 
  slowly, 
  sometimes 
  more 
  rapidly 
  

   on 
  the 
  central 
  part. 
  Again, 
  a 
  little 
  distance 
  away 
  from 
  the 
  

  

  