MILK FOR CITY CONSUMPTION. 143 



unusual powers of resistance can if only in a small degree, 

 develop their specific qualities, and partly because bacteria 

 forming other acids in the milk have been able to de- 

 velop. Even some moulds which do not seem to have any 

 special liking for the light play a certain part in these 

 changes of the milk. 



Considering what has been said, we cannot be surprised 

 that the putrefactive bacteria gain the upper hand in milk 

 kept in dark, small, city cellars or pantries. 



One of the reasons why milk spoils so soon in old 

 and poorly ventilated milk-rooms and depots is, that the 

 infection is allowed to become more intense and thorough 

 with every day, as the rooms are not thoroughly cleaned 

 as often as necessary, and are never disinfected. A 

 mass infection may therefore easily arise by the least 

 motion in the room, and the fermentation in the milk will 

 have a good start. To this must be added that the tem- 

 perature in such milk stores and rooms is often very high. 

 Whenever possible the milk ought to be kept on ice; but 

 where ice is not available a too high temperature may be 

 avoided by taking simple precautions, as, for instance, by a 

 system of ventilation, by keeping the milk in cold running 

 water, etc. 



One side of the question which cannot here be treated 

 fully is, that milk kept under bad conditions may easily 

 become dangerous to human health. I shall here only 

 point out that the conditions favoring the development of 

 the bacteria inimical to the keeping quality of the milk 

 are also favorable to bacteria injurious to human health; 

 in fighting the former we therefore at the same time coun- 

 teract the latter. 



