﻿92 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  A 
  considerable 
  sediment 
  was 
  kept 
  in 
  circulation 
  by 
  the 
  aerating 
  

   current, 
  and 
  as 
  this 
  sediment 
  deposited 
  in 
  the 
  gills 
  to 
  a 
  slight 
  extent 
  

   and 
  might 
  be 
  held 
  to 
  injure 
  mechanically, 
  the 
  agitation 
  due 
  to 
  the 
  air 
  

   was 
  excluded 
  by 
  repeating 
  the 
  trial 
  with 
  two 
  black 
  bass, 
  without 
  aera- 
  

   tion, 
  using 
  a 
  new 
  sample 
  of 
  the 
  polluted 
  water. 
  These 
  bass 
  died 
  in 
  

   one 
  hour, 
  the 
  unaerated 
  controls 
  being 
  unaffected. 
  The 
  agitation 
  

   caused 
  by 
  the 
  struggles 
  of 
  the 
  fish, 
  however, 
  kept 
  the 
  sediment 
  dis- 
  

   tributed 
  about 
  as 
  much 
  as 
  the 
  air 
  current 
  had 
  previously 
  done. 
  

  

  After 
  the 
  remainder 
  of 
  the 
  sample 
  had 
  stood 
  over 
  one 
  night 
  and 
  it 
  

   had 
  cleared 
  considerably 
  by 
  sedimentation, 
  about 
  5 
  gallons 
  were 
  

   siphoned 
  from 
  the 
  middle 
  of 
  the 
  can, 
  so 
  that 
  all 
  the 
  sediment 
  and 
  the 
  

   surface 
  scum 
  were 
  excluded. 
  Into 
  this 
  water 
  were 
  introduced 
  three 
  

   carp 
  between 
  5 
  and 
  6 
  inches 
  in 
  length, 
  four 
  sun-lish 
  of 
  about 
  -i 
  inches, 
  

   four 
  calico 
  bass 
  of 
  3 
  inches, 
  and 
  two 
  rock 
  bass 
  of 
  li 
  inches. 
  All 
  died 
  

   within 
  two 
  hours, 
  the 
  gills 
  free 
  and 
  unclogged, 
  the 
  controls 
  being 
  

   unaffected. 
  

  

  The 
  next 
  day, 
  using 
  the 
  same 
  sample 
  of 
  water, 
  into 
  which 
  the 
  air 
  

   current 
  had 
  been 
  running 
  all 
  night, 
  two 
  very 
  small 
  cat-fish 
  and 
  one 
  of 
  

   about 
  T 
  inches 
  were 
  introduced. 
  The 
  two 
  small 
  ones 
  died 
  in 
  twenty 
  

   and 
  forty-eight 
  hours, 
  respectively, 
  while 
  the 
  larger 
  one 
  was 
  still 
  alive 
  

   at 
  the 
  end 
  of 
  two 
  days, 
  but 
  in 
  distress. 
  The 
  water 
  was 
  then 
  replaced 
  

   by 
  a 
  fresh 
  sample 
  of 
  the 
  polluted 
  water 
  from 
  the 
  fish 
  can, 
  and 
  the 
  

   large 
  cat-fish 
  succumbed 
  in 
  three 
  hours. 
  The 
  aeration 
  seemed 
  to 
  purify 
  

   the 
  polluted 
  sample, 
  evidenced 
  by 
  the 
  reduction 
  in 
  the 
  strength 
  of 
  the 
  

   odor 
  and 
  by 
  the 
  fact 
  that 
  the 
  cat-fish 
  survived 
  in 
  it 
  much 
  longer 
  than 
  

   in 
  a 
  fresh 
  sample 
  from 
  the 
  can. 
  

  

  After 
  the 
  remainder 
  of 
  the 
  sample 
  had 
  stood 
  seven 
  days 
  in 
  the 
  can 
  

   it 
  became 
  comparatively 
  clear. 
  A 
  portion 
  of 
  the 
  clear 
  water 
  was 
  

   poured 
  off 
  without 
  excluding 
  a 
  small 
  amount 
  of 
  scum 
  and 
  the 
  iridescent 
  

   film 
  on 
  the 
  surface, 
  and 
  in 
  it 
  were 
  placed 
  one 
  small 
  calico 
  bass 
  and 
  one 
  

   small 
  rock 
  bass. 
  The 
  former 
  died 
  in 
  one 
  and 
  one-half 
  hours, 
  the 
  latter 
  

   in 
  one 
  hour, 
  the 
  controls 
  living 
  and 
  normal. 
  

  

  The 
  water 
  after 
  settling 
  for 
  seven 
  days 
  was 
  neutral 
  in 
  reaction 
  to 
  

   litmus, 
  and 
  it 
  had 
  a 
  less 
  marked 
  odor 
  than 
  the 
  black 
  unsedimented 
  

   water, 
  but 
  the 
  characteristic 
  tarry 
  odor 
  was 
  still 
  unmistakable. 
  The 
  

   conclusion 
  is 
  that 
  the 
  sample 
  of 
  water 
  in 
  question 
  is 
  readily 
  fatal 
  to 
  

   ordinary 
  fishes 
  and 
  fatal 
  also, 
  but 
  somewhat 
  less 
  quickly, 
  to 
  hardy 
  

   forms 
  such 
  as 
  the 
  cat-fish. 
  

  

  A 
  representative 
  of 
  the 
  Commission 
  testified 
  to 
  the 
  foregoing 
  facts 
  

   in 
  court 
  on 
  summons 
  issued 
  by 
  the 
  government. 
  The 
  defendant 
  was 
  

   found 
  guilty 
  and 
  sentenced 
  — 
  an 
  appeal 
  being 
  taken. 
  

  

  DESTRUCTION 
  OF 
  YOUNG 
  TROUT 
  BY 
  HYDRA. 
  

  

  At 
  the 
  Leadville, 
  Colo. 
  , 
  station 
  of 
  the 
  Commission 
  in 
  the 
  summer 
  of 
  

   ] 
  902, 
  many 
  newly-hatched 
  black-spotted 
  trout 
  were 
  destroyed 
  by 
  an 
  

   agent 
  not 
  previously 
  met 
  with, 
  and 
  the 
  existence 
  of 
  which 
  was 
  not 
  sus- 
  

  

  