196 BACTERIOLOGY. 



The temperature attained under the conditions stated 

 above will not exceed in extreme cases 188 F. (87 C.). 



Milk should be sterilized when it is as fresh as pos- 

 sible, and only sufficient milk for twenty-four hours 

 should be sterilized at one time. If, after nursing, the 

 infant leaves some milk in the bottle, this should be 

 thrown away. 



Care of the Bottles is Important. After nursing,, the 

 bottles should be filled with a strong solution of wash- 

 ing soda, allowed to stand twenty-four hours, and then 

 carefully cleaned with a bristle (bottle) brush. The 

 rubber corks and nipples should be boiled after using 

 in strong soda solution for fifteen minutes and then 

 rinsed and dried. 



After sterilizing milk should never be put into unster- 

 ilized bottles, as this will spoil it. 



A different but admirable method is the one devised 

 by Dr. Freeman. 1 Here a pail is filled to a certain 

 mark with water and then placed on the stove until the 

 water boils. It is then removed, and immediately a 

 milk-holder, consisting of a series of zinc cylinders, is 

 lowered with its milk bottles partially full of milk. 

 The cover is again applied. The heat of the outside 

 water raises the temperature of the milk in ten minutes 

 to 75 C. (167 F.), and holds it nearly at that point 

 for some time. 2 After twenty minutes the milk is re- 

 moved, placed in cold water, and quickly cooled. The 

 milk is kept in the ice-chest until used. 



1 Agent for Pasteurizer, James Dougherty, 411 W. 59th St. 



2 A temperature of 75 C. is advised in Pasteurizing milk, instead of 65 C., 

 which would ordinarily suffice to kill all bacteria free of spores, because of 

 the fact pointed out by Theobald Smith, that the bacteria embedded in the 

 pellicle which forms on the surface are more resistant than those surrounded 

 by fluid. 



