﻿VICTOKIA 
  PARK, 
  WHITEINCH, 
  NEAR 
  GLASGOW. 
  

  

  627 
  

  

  A 
  tendency 
  to 
  spherulitic 
  structure, 
  through 
  the 
  radial 
  grouping 
  

   of 
  small 
  crystals 
  or 
  microliths, 
  may 
  be 
  observed 
  even 
  in 
  this 
  part 
  of 
  

   the 
  vein. 
  These 
  seem 
  to 
  consist 
  chiefly 
  of 
  felspars, 
  more 
  or 
  less 
  

   altered, 
  and 
  there 
  are, 
  besides, 
  a 
  few 
  micro-porphyritic 
  crystals 
  of 
  

   angite 
  and 
  olivine, 
  and 
  some 
  irregularly 
  shaped 
  spaces, 
  now 
  filled 
  

   with 
  calcite, 
  which 
  may 
  in 
  some 
  cases 
  be 
  pseudomorphous 
  after 
  

   olivine, 
  in 
  others 
  an 
  infiltration-deposit 
  in 
  vesicles. 
  The 
  section 
  is 
  

   profusely 
  speckled 
  with 
  minute 
  opaque 
  grains, 
  which, 
  in 
  reflected 
  

   light, 
  appear 
  white 
  or 
  yellowish 
  white. 
  This 
  white 
  matter 
  may 
  

   be 
  partly 
  kaolin, 
  but 
  in 
  some 
  instances 
  it 
  is 
  apparently 
  ]eucoxene, 
  

   resulting 
  from 
  the 
  alteration 
  of 
  ilmenite 
  or 
  titaniferous 
  magnetite, 
  

   the 
  latter 
  being 
  rendered 
  the 
  more 
  probable 
  from 
  the 
  frequent 
  occur- 
  

   rence 
  of 
  this 
  white 
  substance 
  in 
  the 
  form 
  of 
  minute 
  octahedra. 
  

  

  The 
  crystallization 
  in 
  this 
  central 
  portion 
  of 
  the 
  vein 
  has 
  a 
  some- 
  

   what 
  coarser 
  character 
  than 
  in 
  the 
  marginal 
  parts. 
  Micro-porphy- 
  

   ritic 
  pseudomorphs 
  are 
  to 
  be 
  seen 
  here 
  and 
  there 
  ; 
  they 
  consist 
  of 
  

   calcite, 
  having 
  a 
  slightly 
  rusty 
  stain, 
  and 
  are 
  sometimes 
  bordered 
  by 
  

   a 
  narrow 
  zone 
  of 
  limonite. 
  

  

  In 
  some 
  cases 
  they 
  are 
  pseudomorphs 
  after 
  augite. 
  One 
  section 
  

   taken 
  in 
  the 
  plane 
  of 
  symmetry 
  gave 
  the 
  angle 
  100 
  : 
  001 
  = 
  74°; 
  

   another, 
  approximately 
  basal, 
  gave 
  the 
  angle 
  110 
  : 
  110 
  = 
  86°. 
  

  

  In 
  this 
  portion 
  of 
  the 
  vein 
  what 
  appear 
  to 
  be 
  minute 
  garnets 
  are 
  

   somewhat 
  plentiful. 
  They 
  mostly 
  occur 
  in 
  rounded 
  grains, 
  but 
  

   small 
  rhombic-dodecahedra 
  may 
  occasionally 
  be 
  detected. 
  

  

  Section 
  of 
  White- 
  Whin 
  Vein, 
  Victoria 
  Parle, 
  Whiteinch, 
  near 
  

   Glasgow. 
  (Natural 
  size.) 
  

  

  a 
  a. 
  Densely 
  spherulitic 
  bands. 
  

  

  bb. 
  Colourless 
  vitreous 
  bands 
  with 
  spherules. 
  

  

  c 
  c. 
  Brown 
  or 
  coffee-coloured 
  vitreous 
  bands, 
  showing 
  distinct 
  fluxion-banding 
  

  

  and 
  containing 
  a 
  few 
  small 
  spherules. 
  

   d. 
  Dark 
  shale. 
  This 
  has 
  been 
  broken 
  away 
  from 
  the 
  under 
  surface 
  of 
  the 
  

  

  specimen. 
  

  

  The 
  central 
  portion 
  of 
  the 
  vein 
  has 
  a 
  confusedly 
  crystalline 
  structure. 
  

  

  On 
  passing 
  from 
  the 
  middle 
  of 
  the 
  vein 
  towards 
  the 
  margin 
  the 
  

   proportion 
  of 
  opaque 
  white 
  matter 
  diminishes, 
  and 
  an 
  increase 
  of 
  

   vitreous 
  material, 
  coupled 
  with 
  a 
  more 
  marked 
  tendency 
  to 
  spheru- 
  

   litic 
  structure, 
  is 
  met 
  with, 
  a 
  zone 
  of 
  densely 
  packed 
  spherules 
  

   (indicated 
  by 
  the 
  letter 
  a 
  in 
  the 
  accompanying 
  figure) 
  eventually 
  

   resulting. 
  This 
  spherulitic 
  zone 
  ends 
  abruptly, 
  and 
  is 
  succeeded 
  by 
  

  

  