24 DAIRY TECHNOLOGY 



may be found in the milk. Ingestion of such milk by a 

 human being may cause severe gastro-intestinal trouble. 

 Leaves of the common artichoke are also said to produce 

 certain toxic properties in the milk which cause abdominal 

 pains and diarrhea in the consumer. In a few instances, 

 milk sellers unlawfully add preservatives, such as formalin. 



Colored Milk. Milk may have a reddish color due 

 to the presence of blood in the milk, or such color may 

 be caused by bacterial growth. Eating certain plants 

 may affect the color of the milk. Bacillus cyanogenes 

 is known to have infected dairies and caused a bluish dis- 

 coloration of the milk. 



Bitter Milk. Bitter milk occasionally may be observed 

 during the late stages of lactation. It may be caused by 

 the cow eating lupines, wormwood, etc., or it may be the 

 result of bacterial growth. 



Stringy or Ropy Milk. Stringy or ropy milk is caused 

 by a growth of bacteria that are surrounded by a gummy 

 capsule. So far as known there is nothing harmful about 

 this fermentation, but milk of this kind is very distasteful 

 to most people in this country. Some foreign people 

 consider ropy milk a desirable beverage. In some in- 

 stances they produce this condition by introducing into 

 the milk leaves of certain plants on which bacteria causing 

 milk to be ropy are found. Edam cheese is nearly all made 

 from milk that has undergone this or similar fermentation. 

 In modern factories pure cultures of this particular fer- 

 ment (Bacillus Hollandicus) are propagated. 



Colostrum. This substance, although the natural 

 product of the mammary glands, is not milk according 

 to our pure food laws. We may, however, from the stand- 

 point of human food call it abnormal milk. Colostrum 

 is a yellow, viscid fluid of abnormal milk odor, and some- 



