MICRO-ORGANISMS IN MILK 333 



Milk should be taken into the house as soon as possible after 

 delivery and placed immediately on ice. It should not be per- 

 mitted to stand on tables or any place where its temperature may 

 rise. As mentioned in another connection, when left outside the 

 milk is exposed to the sun, the temperature of the air, and also to 

 sampling by domestic animals. The expansion caused by heat or 

 freezing may push the cap out of place, and the danger of ex- 

 posure becomes more imminent. The menace is increased in 

 summer by the presence of flies and other insects. 



In the house the bottles should always be covered. Practical 

 inexpensive devices for removing the cap can be purchased, and 

 the same devices serve as covers. Good covers protect not only 

 against bacterial invasion but also against absorption of odors. 

 The refrigerator, of course, must be kept clean, and spoiled food 

 should not be permitted to accumulate. 



Before opening a bottle of milk the neck and covering should 

 be wiped with a clean cloth. After emptying, bottles should be 

 washed first in cold or lukewarm water and then in soapsuds. 

 This will largely prevent bacterial multiplication in empty bottles 

 and render cleaning easier for the producer. 



Milk bottles should be kept out of sick rooms. The con- 

 sumer can do much to encourage production of clean milk by visit- 

 ing dairies. He can judge of the conditions prevailing at the dairy 

 and will incidentally see some of the abuses that milk bottles are 

 exposed to. In many dairies milk bottles have accumulated that 

 have been used as containers for various foods, paints, varnishes, 

 etc. Such abuse renders them practically useless for further 

 delivery. 



It has been shown on the previous pages that micro-organisms 

 may gain access to milk at different stages during its journey 

 from cow to consumer. The original contamination from the 

 udder is not great, but pollution from the cow and from utensils 

 may be considerable. The amount of pollution depends primarily 

 upon the quantity of dirt that falls into the milk. Subsequently, 

 lack of cleanliness of utensils and machinery may increase the 

 germ content materially, and finally failure to cool milk promptly 

 and to keep it cool encourages multiplication of the micro-organ- 

 isms that originally gained access. 



As it seems impossible to keep all foreign matter out of milk, 

 the attempt is made to reduce the amount to a minimum. This 

 is accomplished in large measure by producers of certified milk, 

 but considerable expense is involved in the process, and it can- 

 not be applied under present conditions to the bulk of milk 

 consumed. 



But clean milk can be produced without as great expense as is 



