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  Galloway 
  — 
  Rounding 
  of 
  Sand 
  by 
  Solution. 
  

  

  grains 
  by 
  solution 
  is 
  similar 
  to 
  the 
  formation 
  of 
  rounded 
  

   bowlders 
  by 
  exfoliation 
  of 
  granite, 
  by 
  weathering 
  of 
  

   basalt, 
  the 
  rounding 
  of 
  bowlders 
  and 
  mineral 
  fragments 
  

   by 
  abrasion, 
  and 
  the 
  tendency 
  of 
  chunks 
  of 
  ice 
  to 
  become 
  

   round 
  in 
  melting, 
  differing 
  mainly 
  in 
  the 
  size 
  of 
  particles 
  

  

  Fig. 
  1. 
  

  

  Fig. 
  1. 
  Grains 
  of 
  crushed 
  Iceland 
  spar 
  rounded 
  by 
  solution 
  in 
  warm 
  

   hydrochloric 
  acid. 
  Note 
  that 
  the 
  smallest 
  grains 
  are 
  the 
  most 
  nearly 
  round. 
  

   Transmitted 
  light. 
  Magnified 
  70 
  diameters. 
  

  

  removed 
  from 
  the 
  respective 
  surfaces. 
  In 
  all 
  these 
  

   methods 
  of 
  rounding, 
  the 
  larger 
  amount 
  of 
  material 
  is 
  

   removed 
  from 
  the 
  corners. 
  

  

  The 
  surfaces 
  of 
  grains 
  rounded 
  by 
  rapid 
  solution, 
  or 
  

   solution 
  accompanied 
  by 
  motion 
  of 
  the 
  grains, 
  are 
  smooth 
  

   like 
  glass, 
  though 
  sometimes 
  minutely 
  pitted 
  or 
  corroded, 
  

   but 
  never 
  "frosted" 
  like 
  ground 
  glass. 
  When 
  solution 
  

   is 
  very 
  slow, 
  as 
  in 
  the 
  case 
  of 
  weathering 
  of 
  quartzite 
  

   pebbles 
  in 
  conglomerates, 
  or 
  vein 
  quartz, 
  or 
  the 
  corrosion 
  

   of 
  quartz 
  grains 
  in 
  decomposed 
  granite 
  and 
  residual 
  soils, 
  

   glacial 
  till 
  and 
  clays 
  which 
  I 
  have 
  examined, 
  the 
  surfaces 
  

   are 
  dull, 
  giving 
  an 
  effect 
  easily 
  mistaken 
  for 
  that 
  pro- 
  

  

  