﻿844 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  following 
  shows 
  the 
  more 
  important 
  results 
  of 
  the 
  weekly 
  

   biological 
  examinations 
  of 
  Hemlock 
  lake 
  water 
  which 
  have 
  taken 
  

   place 
  from 
  1896-1902, 
  inclusive. 
  These 
  determinations 
  have 
  been 
  

   made 
  by 
  Prof. 
  Charles 
  Wright 
  Dodge, 
  of 
  the 
  University 
  of 
  Roch- 
  

   ester, 
  using 
  for 
  the 
  plant 
  and 
  animal 
  organisms, 
  exclusive 
  of 
  bac- 
  

   teria, 
  amount 
  of 
  amorphous 
  matter, 
  average 
  number 
  of 
  moulds, 
  

   etc. 
  the 
  iSedgwick-Rafter 
  method. 
  1 
  The 
  determinations 
  of 
  bac- 
  

   teria 
  have 
  been 
  made 
  by 
  standard 
  bacteriological 
  methods. 
  

  

  (i) 
  

  

  Average 
  number 
  of 
  plant 
  and 
  animal 
  

   organisms 
  (exclusive 
  of 
  bacteria) 
  per 
  

   cubic 
  centimeter 
  of 
  unfiltered 
  water, 
  

   i. 
  e., 
  water 
  as 
  it 
  comes 
  from 
  the 
  tap. 
  . 
  . 
  

  

  Average 
  amount 
  of 
  amorphous 
  matter, 
  

   i. 
  e., 
  iron 
  rust 
  from 
  the 
  pipes, 
  earthy 
  

   matter, 
  etc., 
  in 
  standard 
  units 
  per 
  

   cubic 
  centimeter 
  of 
  unfiltered 
  water. 
  . 
  

  

  Average 
  number 
  of 
  bacteria 
  per 
  cubic 
  

   centimeter 
  of 
  unfiltered 
  water 
  

  

  Average 
  number 
  of 
  moulds 
  per 
  cubic 
  

   centimeter 
  of 
  unfiltered 
  water 
  

  

  Average 
  number 
  of 
  genera 
  of 
  organisms 
  

   per 
  examination 
  

  

  1896 
  

  

  1897 
  

  

  1898 
  

  

  1899 
  

  

  1900 
  

  

  1901 
  

  

  (3) 
  

  

  (4) 
  

  

  (5) 
  

  

  (6) 
  

  

  (7) 
  

  

  135.95 
  

  

  83.26 
  

  

  68.82. 
  

  

  74.94 
  

  

  56.88 
  

  

  88.07 
  

  

  74.41 
  

  

  48.84 
  

  

  43.0 
  

  

  41.37 
  

  

  37.71 
  

  

  38.59 
  

  

  334.0 
  

  

  101.0 
  

  

  94.0 
  

  

  51.0 
  

  

  52.2 
  

  

  103.75 
  

  

  3.8 
  

  

  10.6 
  

  

  14.4 
  

  

  8.4 
  

  

  8.9 
  

  

  16.0 
  

  

  9.4 
  

  

  8.2 
  

  

  6.6 
  

  

  7.5 
  

  

  5.6 
  

  

  6.1 
  

  

  1902 
  

   "W 
  

  

  141.69 
  

  

  41.87 
  

  

  102.70 
  

  

  16.45 
  

  

  5.14 
  

  

  The 
  following 
  eighteen 
  sources 
  were 
  considered: 
  Gates 
  bored 
  

   well; 
  driven 
  or 
  bored 
  wells 
  in 
  the 
  bottom 
  lands 
  south 
  of 
  Mount 
  

   Hope 
  reservoir; 
  Irondequoit 
  creek 
  and 
  its 
  tributaries; 
  Red 
  creek; 
  

   Little 
  Black 
  creek; 
  springs 
  and 
  well 
  at 
  Ooldwater; 
  Snow 
  

   springs 
  ; 
  Hubbard 
  springs 
  ; 
  Black 
  creek 
  ; 
  Oatka 
  creek 
  ; 
  Caledonia 
  

   springs; 
  Mendon 
  ponds; 
  pond 
  near 
  Bushnell 
  Basin; 
  Ironde- 
  

   quoit 
  bay; 
  Lake 
  Ontario; 
  Erie 
  canal; 
  Honeoye 
  creek 
  at 
  East 
  

   Rush, 
  and 
  Genesee 
  river. 
  The 
  following 
  is 
  a 
  brief 
  description 
  

   of 
  these 
  several 
  sources 
  as 
  mostly 
  taken 
  from 
  the 
  reports 
  of 
  the 
  

   Executive 
  Board 
  of 
  Rochester. 
  

  

  The 
  Gates 
  well. 
  This 
  well 
  is 
  situated 
  about 
  one 
  mile 
  west 
  of 
  

   the 
  Rochester 
  city 
  line. 
  The 
  surface 
  of 
  the 
  ground 
  at 
  the 
  well 
  is 
  

   27.5 
  feet 
  above 
  the 
  Erie 
  canal 
  aqueduct, 
  or 
  96.5 
  feet 
  below 
  the 
  nor- 
  

   mal 
  water 
  surface 
  in 
  Mount 
  Hope 
  reservoir. 
  A 
  test 
  of 
  the 
  quantity 
  

   of 
  water 
  to 
  be 
  obtained 
  from 
  this 
  well 
  was 
  made 
  by 
  the 
  writer 
  in 
  

   the 
  latter 
  part 
  of 
  May, 
  1890, 
  and 
  a 
  full 
  report 
  of 
  the 
  results 
  of 
  

  

  lr 
  rhis 
  method 
  of 
  biological 
  analysis 
  is 
  described 
  in 
  The 
  Microscopical 
  

   Examination 
  of 
  Potable 
  Water, 
  by 
  Geo. 
  W. 
  Rafter. 
  See 
  also 
  The 
  Microscopy 
  

   of 
  Drinking 
  Water, 
  by 
  Geo. 
  C. 
  Whipple. 
  

  

  