﻿THE 
  BACTEKIA 
  209 
  

  

  killed. 
  If 
  such 
  completely 
  sterilized 
  food 
  is 
  hermetically 
  sealed 
  

   in 
  vessels 
  that 
  have 
  been 
  similarly 
  sterilized, 
  it 
  will 
  not 
  decay. 
  

   It 
  is 
  difficult, 
  but 
  entirely 
  possible, 
  to 
  thoroughly 
  sterilize 
  both 
  

   food 
  and 
  sealing 
  appliances 
  so 
  that 
  absolutely 
  no 
  organisms 
  

   will 
  grow. 
  1 
  Other 
  methods 
  of 
  preservation 
  by 
  the 
  introduction 
  

   of 
  chemicals 
  (antiseptics) 
  that 
  prevent 
  the 
  growth 
  of 
  bacteria 
  

   are 
  sometimes 
  used. 
  These 
  chemical 
  preventives 
  are 
  poisons. 
  

   If 
  eaten 
  in 
  very 
  small 
  quantities, 
  injurious 
  results 
  may 
  not 
  be 
  

   immediately 
  noticeable, 
  but 
  the 
  use 
  of 
  these 
  preventives 
  is 
  at- 
  

   tended 
  by 
  constant 
  danger. 
  Milk, 
  meats, 
  and 
  confections 
  that 
  

   are 
  so 
  preserved 
  should 
  always 
  be 
  avoided.' 
  2 
  

  

  195. 
  Preservation 
  of 
  milk 
  and 
  water 
  supply. 
  The 
  relation 
  

   of 
  bacteria 
  to 
  milk 
  and 
  water 
  supply 
  is 
  a 
  subject 
  of 
  the 
  great- 
  

   est 
  importance. 
  A 
  rather 
  large 
  number 
  of 
  harmless 
  bacteria 
  

   may 
  often 
  be 
  found 
  in 
  reasonably 
  pure 
  milk 
  and 
  water, 
  but 
  

   careless 
  handling 
  of 
  bottles 
  and 
  cans, 
  or 
  the 
  use 
  of 
  tubercu- 
  

   lous 
  cows, 
  may 
  result 
  in 
  widespread 
  disease. 
  If 
  milking 
  is 
  

   done 
  through 
  absorbent 
  cotton 
  or 
  through 
  several 
  layers 
  of 
  

   cheesecloth, 
  used 
  as 
  a 
  cover 
  for 
  the 
  milk 
  pail, 
  most 
  of 
  the 
  

   impurities 
  are 
  caught 
  in 
  the 
  strainers. 
  Milk 
  pails 
  and 
  ship- 
  

   ping 
  cans 
  and 
  milk 
  bottles 
  should 
  always 
  be 
  sterilized 
  before 
  

   they 
  are 
  used. 
  Milkmen 
  who 
  were 
  otherwise 
  fairly 
  careful 
  in 
  

   their 
  work 
  have 
  been 
  known 
  to 
  rinse 
  their 
  pails 
  and 
  cans 
  in 
  

   polluted 
  wells 
  or 
  streams. 
  Bacteria 
  which 
  produce 
  various 
  

   kinds 
  of 
  disease 
  have 
  thus 
  been 
  distributed. 
  Either 
  milk 
  or 
  

   water 
  may 
  be 
  sterilized 
  by 
  boiling, 
  and 
  may 
  be 
  kept 
  sterile 
  if 
  

   placed 
  in 
  sterile 
  vessels. 
  Both, 
  however, 
  are 
  better 
  if 
  they 
  can 
  

   be 
  kept 
  in 
  a 
  pure 
  condition 
  without 
  sterilization. 
  An 
  efficient 
  

   method 
  of 
  preserving 
  milk 
  is 
  by 
  pasteurization, 
  3 
  in 
  which 
  the 
  

  

  1 
  Abel, 
  Mrs. 
  Mary 
  Hinman, 
  "Care 
  of 
  Food 
  in 
  the 
  Home," 
  Farmers'' 
  Bul- 
  

   letin 
  375, 
  U.S. 
  Dept. 
  Agr., 
  1909. 
  

  

  2 
  Sometimes 
  in 
  canned 
  goods, 
  stale 
  meats, 
  and 
  other 
  foods, 
  poisonous 
  sub- 
  

   stances 
  known 
  as 
  ptomaines 
  are 
  formed. 
  It 
  is 
  supposed 
  that 
  they 
  are 
  pro- 
  

   duced 
  as 
  secretions 
  from 
  bacteria, 
  as 
  results 
  of 
  chemical 
  change 
  or 
  decay 
  of 
  

   such 
  foods 
  as 
  meats 
  and 
  fruits, 
  or 
  even 
  from 
  the 
  disorganization 
  of 
  some 
  of 
  

   the 
  bacteria. 
  

  

  3 
  " 
  Directions 
  for 
  the 
  Home 
  Pasteurization 
  of 
  Milk," 
  Circular 
  152, 
  Bureau 
  

   of 
  Animal 
  Industry, 
  U.S. 
  Dept. 
  Agr., 
  1912. 
  

  

  