﻿OYSTERS 
  AND 
  METHODS 
  OF 
  OYSTER-CULTURE. 
  283 
  

  

  which 
  will 
  be 
  the 
  readiug 
  of 
  the 
  scale 
  nearest 
  the 
  point 
  where 
  the 
  sur- 
  

   face 
  of 
  the 
  water 
  touches 
  the 
  stem. 
  For 
  purposes 
  of 
  oyster-culture 
  the 
  

   finer 
  graduations 
  may 
  be 
  neglected. 
  To 
  show 
  the 
  specific 
  gravity, 
  the 
  

   number 
  "1.0" 
  should 
  always 
  be 
  placed 
  in 
  front 
  of 
  the 
  scale 
  reading; 
  

   for 
  example, 
  if 
  the 
  surface 
  of 
  tlie 
  water 
  should 
  stand 
  opposite 
  the 
  scale 
  

   reading 
  "15," 
  the 
  density 
  would 
  be 
  1.015. 
  The 
  test 
  should 
  be 
  made 
  

   immediately 
  after 
  the 
  water 
  specimen 
  has 
  been 
  collected 
  and 
  a 
  reading 
  

   of 
  the 
  thermometer 
  should 
  be 
  taken 
  at 
  the 
  same 
  time. 
  

  

  For 
  practical 
  purposes 
  on 
  the 
  oyster-beds, 
  a 
  bottle 
  or 
  jar 
  not 
  less 
  than 
  

   10 
  inches 
  deep 
  may 
  be 
  used 
  instead 
  of 
  the 
  copper 
  cup, 
  and 
  any 
  ordinary 
  

   thermometer 
  may 
  be 
  used 
  for 
  obtaining 
  the 
  temperature. 
  The 
  cheap, 
  

   wooden-cased 
  instruments 
  known 
  as 
  "bath 
  thermometers" 
  serve 
  very 
  

   well, 
  as 
  they 
  have 
  no 
  metal 
  parts 
  to 
  be 
  corroded 
  by 
  the 
  salt 
  water. 
  In 
  

   most 
  oyster 
  regions 
  the 
  salinometer 
  reading 
  from 
  1.020 
  to 
  1.031 
  will 
  

   not 
  be 
  necessary, 
  as 
  the 
  density 
  on 
  the 
  oyster-beds 
  rarely 
  falls 
  within 
  

   its 
  range. 
  

  

  The 
  specimens 
  of 
  water 
  should 
  be 
  from 
  the 
  bottom, 
  or 
  near 
  it, 
  and 
  

   may 
  be 
  conveniently 
  obtained 
  by 
  the 
  following 
  rough 
  method: 
  An 
  

   empty 
  jug 
  or 
  large 
  bottle 
  weighted 
  and 
  corked 
  is 
  lowered 
  to 
  the 
  bottom 
  

   by 
  means 
  of 
  a 
  line. 
  The 
  cork 
  is 
  then 
  pulled 
  out 
  by 
  jerking 
  on 
  a 
  cord 
  

   previously 
  attached 
  to 
  it, 
  the 
  receptacle 
  fills 
  with 
  a 
  sample 
  of 
  water 
  

   from 
  or 
  near 
  the 
  bottom, 
  and 
  if 
  hauled 
  rapidly 
  to 
  the 
  surface 
  it 
  answers 
  

   the 
  practical 
  purposes 
  of 
  more 
  scientific 
  and 
  accurate 
  apparatus. 
  

  

  SILT, 
  MUD, 
  AND 
  SUSPENDED 
  MATTER. 
  

  

  A 
  bottom 
  composed 
  of 
  soft 
  mud, 
  into 
  which 
  the 
  young 
  oysters 
  would 
  

   sink 
  and 
  become 
  stifled, 
  is 
  unfavorable 
  to 
  oyster- 
  culture 
  or 
  to 
  the 
  de- 
  

   velopment 
  of 
  natural 
  beds. 
  If, 
  however, 
  hard 
  objects 
  are 
  distributed 
  

   over 
  the 
  bottom 
  they 
  will 
  become 
  collectors 
  of 
  spat 
  so 
  long 
  as 
  the 
  

   surface 
  remains 
  clean 
  and 
  free 
  from 
  slime 
  and 
  sediment, 
  and 
  the 
  

   importance 
  of 
  having 
  water 
  containing 
  as 
  little 
  sedimentary 
  matter 
  

   as 
  possible 
  is 
  manifest 
  if 
  it 
  is 
  desired 
  to 
  produce 
  permanent 
  beds 
  or 
  

   catch 
  the 
  floating 
  fry. 
  

  

  Oysters 
  will 
  grow 
  more 
  rapidly 
  on 
  muddy 
  bottoms, 
  or 
  in 
  their 
  vicinity, 
  

   than 
  they 
  will 
  elsewhere, 
  as 
  such 
  situations 
  are 
  usually 
  more 
  pro- 
  

   ductive 
  of 
  food 
  materials. 
  This 
  food 
  is 
  in 
  the 
  form 
  of 
  suspended 
  or 
  

   swimming 
  organic 
  particles, 
  and, 
  therefore, 
  filtered 
  water, 
  or 
  that 
  which 
  

   is 
  devoid 
  of 
  suspended 
  matter 
  of 
  all 
  kinds, 
  lacks 
  one 
  of 
  the 
  essential 
  

   requirements 
  of 
  successful 
  oyster-culture. 
  The 
  most 
  desirable 
  water 
  

   is 
  that 
  which 
  contains 
  an 
  abundance 
  of 
  minute 
  living 
  particles 
  with 
  a 
  

   minimum 
  of 
  suspended 
  inorganic 
  matter. 
  An 
  organic 
  slime, 
  however, 
  

   such 
  as 
  rapidly 
  forms 
  on 
  exposed 
  surfaces 
  in 
  some 
  localities, 
  is 
  as 
  

   effectual 
  in 
  preventing 
  fixation 
  as 
  is 
  inorganic 
  sediment. 
  In 
  many 
  

   places 
  in 
  Chesapeake 
  Bay 
  and 
  in 
  the 
  bays 
  on 
  the 
  New 
  Jersey 
  coast 
  the 
  

   sediment, 
  as 
  well 
  as 
  the 
  bottom 
  mud, 
  is 
  largely 
  composed 
  of 
  the 
  finely 
  

   comminuted 
  fragments 
  of 
  vegetable 
  matter, 
  seaweeds, 
  etc., 
  the 
  rapid 
  

   deposit 
  of 
  which 
  soon 
  covers 
  with 
  a 
  soft 
  film 
  the 
  surface 
  of 
  all 
  objects 
  

  

  