﻿356 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [4] 
  

  

  enveloping 
  membrane, 
  which 
  finally 
  breaks, 
  either 
  by 
  too 
  great 
  a 
  tension 
  

   or 
  from 
  some 
  other 
  cause, 
  they 
  live 
  a 
  life 
  of 
  their 
  own, 
  as 
  they 
  do 
  not 
  

   seem 
  to 
  adhere 
  at 
  any 
  point 
  to 
  the 
  tissues 
  among 
  which 
  they 
  are 
  found. 
  

   When 
  freed, 
  the 
  pearl 
  falls 
  in 
  the 
  folds 
  of 
  the 
  mantle 
  or 
  in 
  the 
  cavity 
  of 
  

   the 
  valves. 
  In 
  this 
  latter 
  case, 
  if 
  the 
  animal 
  does 
  not 
  succeed 
  in 
  eject- 
  

   ing 
  it— 
  which 
  it 
  generally 
  tries 
  to 
  do 
  — 
  the 
  pearl 
  adheres 
  after 
  a 
  few 
  

   days 
  to 
  the 
  shell, 
  and 
  by 
  constant 
  additions 
  of 
  new 
  layers 
  of 
  mother-of- 
  

   pearl 
  to 
  the 
  entire 
  inner 
  side 
  of 
  the 
  shell, 
  it 
  finally 
  becomes 
  wholly 
  im- 
  

   bedded 
  in 
  it. 
  

  

  Pearls 
  protruding 
  from 
  the 
  shell 
  are 
  used 
  in 
  articles 
  of 
  jewelry 
  or 
  

   ornaments 
  where 
  a 
  portion 
  of 
  the 
  pearl 
  can 
  be 
  hid. 
  As 
  regards 
  those 
  

   which 
  are 
  imbedded 
  in 
  the 
  mother-of-pearl, 
  a 
  Paris 
  jeweler 
  (Mr. 
  Daniel 
  

   Leoboldti) 
  has 
  found 
  a 
  way 
  to 
  extract 
  them 
  without 
  breaking 
  them 
  ; 
  

   after 
  which, 
  by 
  a 
  special 
  process, 
  they 
  are 
  made 
  so 
  perfect 
  that 
  these 
  

   pearls, 
  which 
  are 
  otherwise 
  natural 
  pearls, 
  are 
  currently 
  sold 
  under 
  the 
  

   name 
  of 
  Panama 
  pearls, 
  their 
  primitive 
  value 
  being 
  now 
  restored. 
  

  

  Many 
  pearls, 
  also, 
  are 
  changed 
  by 
  a 
  manual 
  process 
  before 
  they 
  are 
  

   exposed 
  in 
  the 
  jeweler's 
  window. 
  This 
  is 
  done 
  sometimes 
  with 
  pearls 
  

   whose 
  luster 
  is 
  only 
  veiled 
  by 
  some 
  peripheric 
  layers, 
  which 
  arc 
  re- 
  

   moved; 
  some, 
  also, 
  from 
  being 
  pear-shaped, 
  are 
  made 
  round 
  by 
  being 
  

   delicately 
  worked; 
  others 
  are 
  made 
  black. 
  by 
  soaking 
  them 
  in 
  a 
  bath 
  

   of 
  nitrate 
  of 
  silver. 
  It 
  can 
  hardly 
  be 
  imagined 
  what 
  ingenious 
  devices 
  

   have 
  been 
  employed 
  to 
  give 
  to 
  pearls 
  of 
  little 
  value 
  the 
  appearance 
  of 
  

   fine 
  pearls. 
  Means 
  have 
  been 
  found 
  to 
  make 
  them 
  rose-colored, 
  lilac, 
  

   yellow, 
  gray, 
  &c. 
  ; 
  but, 
  on 
  the 
  other 
  hand, 
  ways 
  have 
  been 
  found 
  to 
  

   discover 
  these 
  deceptions. 
  

  

  There 
  are 
  also 
  pearls 
  which 
  are 
  called 
  fine 
  pearls, 
  but 
  are 
  not 
  such 
  in 
  

   reality. 
  These 
  are 
  caused 
  by 
  the 
  perforation 
  of 
  the 
  shells 
  by 
  the 
  ani- 
  

   mals. 
  They 
  are 
  hollow 
  inside, 
  and 
  contain 
  substances 
  having 
  no 
  rela- 
  

   tion 
  whatever 
  to 
  mother-of-pearl, 
  and 
  all 
  of 
  them 
  have 
  a 
  large 
  and 
  

   distinctly 
  marked 
  stem. 
  Besides 
  pearls, 
  the 
  pearl-oyster 
  also 
  produces 
  

   a 
  mother-of-pearl 
  protuberance, 
  of 
  irregular 
  shape, 
  which 
  sometimes 
  

   reaches 
  the 
  size 
  of 
  a 
  pigeon-egg. 
  These 
  excrescences 
  or 
  swellings 
  are 
  

   due 
  to 
  the 
  presence 
  of 
  foreign 
  bodies 
  in 
  the 
  oyster. 
  It 
  is 
  not 
  difficult 
  

   to 
  cause 
  their 
  formation 
  ; 
  all 
  that 
  is 
  required 
  is 
  to 
  attach 
  to 
  the 
  inside 
  

   of 
  the 
  valve 
  a 
  piece 
  of 
  hard 
  substance 
  — 
  stone, 
  glass, 
  or 
  coral 
  — 
  which 
  

   will 
  soon 
  be 
  covered 
  with 
  glandular 
  secretions, 
  taking 
  from 
  the 
  pearls 
  

   their 
  transparency 
  and 
  from 
  the 
  mother-of-pearl 
  their 
  iridescence. 
  It 
  

   is 
  well 
  known 
  that 
  the 
  Chinese 
  manufacture 
  pearls 
  by 
  introducing 
  be- 
  

   tween 
  the 
  valves 
  of 
  certain 
  shells 
  solid 
  bodies 
  on 
  which 
  secretions 
  arc 
  

   soon 
  deposited. 
  

  

  An 
  experiment 
  that 
  I 
  made 
  at 
  Tahiti 
  in 
  order 
  to 
  obtain 
  internal 
  pro- 
  

   tuberances 
  of 
  different 
  kinds 
  by 
  artificial 
  means 
  was 
  as 
  follows: 
  By 
  the 
  

   aid 
  of 
  a 
  gimlet, 
  holes 
  were 
  drilled 
  in 
  different 
  parts 
  of 
  the 
  shell 
  of 
  the 
  

   pearl-oyster; 
  and 
  through 
  these 
  holes, 
  measuring 
  from 
  one 
  centimeter 
  

   to 
  a 
  centimeter 
  aud 
  a 
  half 
  in 
  diameter 
  [about 
  half 
  an 
  inch], 
  small 
  glass 
  

   or 
  stone 
  balls 
  were 
  introduced, 
  held 
  by 
  a 
  brass 
  wire, 
  A 
  stopper 
  of 
  cork 
  

  

  