124 MILK HYGIENE 



nausea and vomiting may be caused, even in adults, and 

 tliere are many instances of the poisoning of large num- 

 bers of people by such milk. This alteration is most fre- 

 quently observed in summer when the milk is not prop- 

 erly cooled, and occurs especially in milk that has been 

 warmed or even boiled for a short time [pasteurized], 

 without sufficient cooling afterward. 



Slimy milk. According to information at hand, the 

 slimy change seems to have no harmful effect, although 

 it may make the milk most unappetizing. In Sweden, 

 however, this change is produced and " langmjolk " is 

 prepared for food, as sour milk (curds and whey) is 

 prepared in other countries. Milk that is inclined to the 

 slimy change should not, at any rate, be fed to small 

 children. 



Some bacteria that occur in milk but which, on ac- 

 count of their properties or small number, do not have 

 any noticeable effect upon the appearance or changes 

 of the milk, may still be harmful. These are sporulat- 

 ing forms, as the hay bacilli or members of the group of 

 butyric acid bacilli, which may break up the casein with 

 the formation of albumoses, peptones and amid- and am- 

 monia compounds. Sometimes there are bacteria which 

 generate special poisons that go into solution in the milk 

 or that remain attached to the bacteria cells. Little is 

 known of these forms, although the opinion has been 

 frequently expressed that these very bacteria play an 

 important part in the etiology of diarrhoea in children. 

 Finally, there may be bacteria which are pathogenic for 

 animals and for man and that are capable of causing 

 inflammation. Such bacteria are very common in mar- 

 ket milk. In the examination of 56 samples of market 

 milk in Berlin, Beck found streptococci in 34, which 

 caused fatal enteritis when fed to rabbits and guinea 

 pigs. In injecting milk in the abdominal cavity of rab- 



