l62 PROTECTION OF THE CONSUMER. 



proved in recent years that, frequently, a few living spores 

 may be left in some of the bottles after sterilization (192, 

 197). So-called sterilized milk from many sources has been 

 tested, and no establishment has been found whose sterile 

 milk is always sterile. Now, while a few bacteria present 

 are of no great importance in raw milk, the presence of a 

 single living spore in sterilized milk may be a matter of 

 serious import. The sterilized milk is commonly preserved 

 for days, or even weeks, before it is used, this possibility of 

 keeping being one of the chief reasons for using it. During 

 this period a single spore left alive in the milk has a chance 

 to grow and, by the time the milk is used, it may be filled 

 with bacteria in enormous quantities, especially since there 

 will be no lactic bacteria present to check the growth of other 

 species. It has also been shown that, among the bacteria 

 thus left in sterilized milk, there are some which produce 

 toxic poisons, and thus the milk in which they have been 

 growing may be actually poisonous. Lastly, it happens that 

 some of these species produce no visible effect upon the milk, 

 and the milk would thus be used unhesitatingly as a good 

 food for children, although containing bacteria in vast num- 

 bers. These facts make sterilized milk unreliable, and while 

 it is only here and there that a bottle of such milk will 

 undergo these subsequent changes, the fact that such an event 

 does occasionally occur removes from sterilized milk its repu- 

 tation of reliability, and makes it doubtful whether it is much 

 less liable to produce trouble than raw milk. Raw milk must 

 be used fresh, otherwise it will sour. The putrefying bac- 

 teria do not have the chance to develop so abundantly in fresh 

 milk, for the lactic bacteria soon check their growth. Hence 

 raw milk, though full of bacteria, will be pretty sure to be pro- 

 tected from the excessive gro.wth of these toxic bacteria which 

 are found in the sterilized milk. This fact, that sterilized 

 milk is not absolutely reliable, has helped to render the method 

 of treatment unpopular, and its use has declined rather than 



