472 CITY MILK SUPPLY 



The subject of infant mortality has been merely crudely outlined in 

 the preceding paragraphs but it cannot be pursued further. Enough 

 has been said to show that dirty and infected milk is responsible for part 

 of it, but it cannot be successfully maintained that it is for all of it. Any 

 health officer who expects to reduce the infant mortality rate to where 

 it ought to be by the sole agency of a clean milk crusade deludes 

 himself. 



One method of coping with the problem of infant mortality adopted 

 by boards of health is to try to reach the mother in the home. Circulars 

 are issued to expectant mothers telling them to get medical advice, giving 

 them simple rules in regard to dressing, exercise, eating and bathing and 

 warning them not to use patent medicines. Some boards employ nurses 

 and in summer have them devote much of their time to teaching the poor 

 how to care for babies. There is less effort to reach the well-to-do but 

 they are sent circulars on the care of milk in the home which emphasize 

 the necessity of being particularly careful in the selection and care of 

 milk for babies and tell how to pasteurize it. Some of these circulars 

 touch on the use of bottles of the thermos type for holding milk and 

 other liquids that are subject to bacterial decomposition. 



Bottles of the Thermos Type. Such bottles have been studied from 

 this standpoint by Rogers, by Tonney and by Davis. Rogers showed 

 that these bottles act as very effective incubators when their contents 

 reach the temperature of bacterial multiplication that is between 50 

 and 98F. Milk put in them at a temperature of 102F. and containing 

 23,900 bacteria per cubic centimeter in 4J^ hr. had a temperature of 

 95F. and had 1,420,000 bacteria per cubic centimeter and in ?K hr- 

 its temperature dropped to 93F. and its bacterial count had increased 

 to 27,000,000 bacteria per cubic centimeter. If inadequately cooled 

 milk, that is milk at about the temperature it would have in the ordinary 

 ice chest, was put in them it soon reached a temperature where rapid 

 bacterial multiplication took place; thus milk put in the bottles at 46.4F. 

 and containing 49,000 bacteria per cubic centimeter in 24 hr. had a tem- 

 perature of 64F. and a bacterial count of 2,140,000 per cubic centimeter. 

 Thoroughly cooled milk kept well. If put in the bottle at 23F. with a 

 bacterial count of 29,000 per cubic centimeter in 24 hr. the temperature 

 was but 37.4F. and the count 36,000 bacteria per cubic centimeter 

 and in 48 hr. the temperature was 57.2F. and the count only 124,000 

 per cubic centimeter. Tonney showed that milk might be put in these 

 bottles at a temperature of 150F. and kept for 6 to 8 hr. without bacterial 

 multiplication ensuing but that as soon as the temperature of the milk 

 drops to about 115F. rapid bacterial multiplication took place. Davis 

 showed that the bottles cannot be sterilized by washing them with boiling 

 hot water and that in 12 hr., milk that had been heated to various tem- 

 peratures between 120F. and 212F. had bacterial counts so high that 



