134 PRINCIPLES OF BACTERIOLOGY 



until just before the milk is to be used, and then it may be warmed by 

 plunging the bottle in warm water. If properly prepared the milk 

 will taste but little like boiled milk. 



The temperature attained under the conditions stated above will 

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



Milk should be sterilized when it is as fresh as possible, 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. After nursing, the bottles should be filled with 

 a strong solution of washing 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 rnilk should never be put into unsterilized]bottles, 

 as this will spoil it. 



A different but admirable method is the one devised by Dr. Free- 

 man. 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 removed, 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 ordi- 

 narily 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. 



