﻿METHOD 
  OF 
  SEPARATING 
  INSECTS 
  AND 
  OTHER 
  ARTHROPODS 
  FROM 
  SOIL. 
  199 
  

  

  The 
  apparatus 
  consists 
  of 
  an 
  outer 
  case 
  of 
  galvanised 
  iron, 
  supporting 
  three 
  sieves. 
  

   The 
  outer 
  case 
  is 
  41 
  in. 
  high, 
  and 
  18 
  in. 
  square 
  inside. 
  One 
  side 
  and 
  both 
  ends 
  of 
  

   the 
  case 
  are 
  open, 
  except 
  for 
  9 
  in. 
  at 
  the 
  upper 
  end 
  of 
  the 
  open 
  side 
  (fig. 
  1). 
  At 
  

   distances 
  of 
  10 
  in., 
  19 
  in. 
  and 
  28 
  in. 
  respectively 
  from 
  the 
  top, 
  pieces 
  Jin. 
  wide 
  are 
  

   fastened 
  inside 
  round 
  the 
  three 
  sides 
  of 
  the 
  case, 
  forming 
  ledges 
  (fig. 
  2, 
  a) 
  on 
  which 
  

   slide 
  the 
  shelf-pieces 
  described 
  later. 
  The 
  case 
  is 
  strengthened 
  round 
  the 
  top 
  and 
  

   bottom 
  and 
  along 
  the 
  two 
  free 
  sides 
  by 
  having 
  the 
  edge 
  turned 
  over 
  stout 
  wire. 
  

  

  There 
  are 
  three 
  shelf-pieces 
  (fig. 
  2, 
  b), 
  made 
  to 
  slide 
  on 
  the 
  ledges 
  described 
  above, 
  

   each 
  18 
  x 
  18 
  in., 
  the 
  upper 
  one 
  having 
  one 
  inch 
  turned 
  up 
  on 
  its 
  outer 
  side 
  to 
  

   prevent 
  water 
  splashing 
  out 
  there. 
  Each 
  shelf 
  has 
  a 
  circular 
  hole 
  in 
  it, 
  15 
  in. 
  in 
  

   diameter. 
  

  

  Passing 
  through 
  the 
  hole 
  in 
  each 
  shelf, 
  and 
  supported 
  on 
  the 
  shelf 
  by 
  a 
  rim 
  1^ 
  in. 
  

   wide 
  is 
  a 
  funnel, 
  14|in. 
  in 
  diameter. 
  Two 
  of 
  these 
  funnels 
  are 
  alike 
  (fig. 
  2, 
  c, 
  e), 
  

   and 
  the 
  third 
  is 
  larger 
  (fig. 
  2, 
  g). 
  The 
  two 
  smaller 
  funnels 
  have 
  sides 
  which 
  are 
  

   straight 
  for 
  4^ 
  in., 
  and 
  then 
  converge 
  for 
  another 
  4-J 
  in., 
  the 
  diameter 
  of 
  the 
  opening 
  

   at 
  the 
  bottom 
  being 
  10 
  in. 
  The 
  third 
  funnel 
  is 
  of 
  the 
  same 
  diameter 
  as 
  the 
  other 
  

   two, 
  but 
  the 
  straight 
  sides 
  are 
  8£ 
  in. 
  long, 
  and 
  the 
  lower 
  part 
  converges 
  to 
  a 
  hole 
  

   2 
  in. 
  in 
  diameter, 
  to 
  which 
  is 
  fastened 
  a 
  pipe 
  that 
  narrows 
  down 
  to 
  a 
  diameter 
  of 
  

   l|-in., 
  and 
  acts 
  as 
  outlet 
  for 
  the 
  water 
  (fig. 
  2, 
  i), 
  being 
  long 
  enough 
  to 
  carry 
  the 
  

   water 
  clear 
  of 
  the 
  case. 
  

  

  The 
  object 
  of 
  these 
  funnels 
  is 
  to 
  avoid 
  loss 
  of 
  water 
  as 
  the 
  water 
  passes 
  from 
  

   one 
  sieve 
  to 
  the 
  next 
  below, 
  and 
  they 
  are 
  necessary 
  owing 
  to 
  the 
  sieves 
  being 
  perforated 
  

   at 
  the 
  side 
  as 
  well 
  as 
  at 
  the 
  bottom. 
  

  

  Two 
  of 
  the 
  sieves 
  are 
  equal 
  in 
  size 
  and 
  the 
  other 
  larger, 
  corresponding 
  to 
  the 
  

   three 
  funnels 
  into 
  which 
  they 
  fit. 
  Two 
  of 
  the 
  sieves 
  are 
  13 
  in. 
  in 
  diameter 
  and 
  4 
  in. 
  

   deep 
  (fig. 
  2, 
  d,f), 
  while 
  the 
  third 
  is 
  of 
  the 
  same 
  diameter 
  but 
  8 
  in. 
  deep 
  (fig. 
  2, 
  h). 
  

   Each 
  sieve 
  has 
  a 
  rim 
  which 
  projects 
  2 
  in. 
  on 
  the 
  outside, 
  to 
  support 
  the 
  sieve 
  in 
  

   the 
  funnel, 
  and 
  the 
  rim 
  also 
  projects 
  \ 
  in. 
  on 
  the 
  inside 
  to 
  prevent 
  insects 
  from 
  

   crawling 
  out 
  and 
  so 
  being 
  lost. 
  To 
  the 
  rim 
  is 
  fastened 
  in 
  each 
  case 
  a 
  pair 
  of 
  handles 
  

   of 
  convenient 
  size, 
  to 
  facilitate 
  moving 
  the 
  sieves 
  when 
  they 
  are 
  full 
  of 
  soil. 
  

  

  Each 
  of 
  the 
  sieves 
  is 
  strengthened 
  by 
  cross-pieces 
  of 
  stout 
  wire 
  on 
  the 
  outside 
  

   of 
  the 
  bottom, 
  and 
  in 
  addition, 
  in 
  the 
  case 
  of 
  the 
  deepest 
  sieve, 
  by 
  a 
  piece 
  of 
  wire 
  

   round 
  the 
  outside 
  at 
  4 
  in. 
  from 
  the 
  bottom. 
  The 
  two 
  smaller 
  sieves 
  are 
  made 
  of 
  

   perforated 
  zinc 
  with 
  round 
  holes 
  3-5 
  mm. 
  and 
  1-5 
  mm. 
  in 
  diameter 
  respectively, 
  

   and 
  the 
  large 
  sieve 
  is 
  made 
  of 
  brass 
  wire 
  gauze 
  with 
  50 
  meshes 
  to 
  the 
  linear 
  inch. 
  

   Both 
  the 
  sides 
  and 
  bottoms 
  of 
  the 
  sieves 
  are 
  made 
  of 
  these 
  materials 
  in 
  order 
  to 
  

   avoid 
  danger 
  of 
  the 
  sieves 
  overflowing 
  owing 
  to 
  the 
  choking 
  of 
  the 
  holes 
  by 
  soil 
  

   particles. 
  All 
  other 
  parts 
  are 
  made 
  of 
  galvanised 
  iron. 
  

  

  A 
  lead 
  pipe, 
  \ 
  in. 
  in 
  diameter, 
  to 
  one 
  end 
  of 
  which 
  is 
  attached 
  a 
  large 
  rose, 
  is 
  

   clamped 
  to 
  the 
  upper 
  edge 
  of 
  the 
  case, 
  the 
  other 
  end 
  of 
  the 
  pipe 
  (fig. 
  2, 
  k) 
  being 
  con- 
  

   nected 
  with 
  the 
  water 
  supply. 
  The 
  rose 
  (fig. 
  2, 
  1) 
  is 
  3 
  in. 
  in 
  diameter 
  and 
  has 
  34 
  holes, 
  

   each 
  about 
  ^ 
  in. 
  in 
  diameter. 
  The 
  face 
  of 
  the 
  rose 
  is 
  convex, 
  so 
  that 
  the 
  jets 
  from 
  

   the 
  holes 
  diverge, 
  forming 
  a 
  cone. 
  The 
  rose 
  is 
  so 
  arranged 
  that 
  when 
  the 
  water 
  is 
  

   turned 
  on 
  the 
  spray 
  from 
  it 
  spreads 
  sufficiently 
  to 
  cover 
  the 
  bottom 
  of 
  the 
  first 
  sieve, 
  

   the 
  water 
  striking 
  the 
  soil 
  with 
  sufficient 
  force 
  to 
  assist 
  considerably 
  in 
  breaking 
  

   it 
  down. 
  

  

  In 
  use, 
  the 
  sieve 
  with 
  the 
  largest 
  mesh 
  is 
  placed 
  in 
  the 
  upper 
  position, 
  that 
  with 
  

   the 
  smallest 
  mesh 
  in 
  the 
  lowest, 
  and 
  the 
  one 
  of 
  intermediate 
  mesh 
  in 
  the 
  middle. 
  

   The 
  soil 
  to 
  be 
  examined 
  is 
  placed 
  in 
  the 
  upper 
  sieve, 
  the 
  water 
  turned 
  on, 
  and 
  the 
  soil 
  

   is 
  then 
  washed 
  into 
  three 
  lots 
  on 
  the 
  sieves, 
  the 
  finest 
  particles 
  being 
  carried 
  away 
  

   with 
  the 
  waste 
  water. 
  

  

  The 
  water 
  is 
  allowed 
  to 
  run 
  until 
  it 
  passes 
  through 
  clear, 
  all 
  the 
  sieves 
  being 
  stirred 
  

   occasionally, 
  and 
  the 
  upper 
  sieves 
  are 
  removed 
  when 
  the 
  stones 
  in 
  them 
  are 
  washed 
  

   clean, 
  so 
  that 
  the 
  finer 
  particles 
  in 
  the 
  lowest 
  sieve 
  may 
  be 
  more 
  thoroughly 
  washed. 
  

  

  (6750) 
  o 
  2 
  

  

  