Contamination of Milk. 51 



teria per cubic centimeter may be produced by the use 

 of a properly handled milking machine. 



Contamination from the milker. While the milker is 

 a small factor in comparison with the animal in the mat- 

 ter of contamination, yet he can not be neglected, as it 

 is within his power to affect profoundly the quality of 

 the milk. His personal habits as to cleanliness and his 

 appreciation of the precautions necessary in the produc- 

 tion of clean milk have much to do with the contami- 

 nation of the milk. The milking should be done with 

 dry hands, although a little vaseline may be used with 

 effect. The hands should be washed before milking as 

 milk is certain to come in contact with them to some ex- 

 tent. The milking should be done with the whole hand 

 rather than stripping between the thumb and finger; 

 the clothing should be covered with clean overalls and 

 jumper, or at least a clean apron should be worn during 

 the milking. If these are of white material, more fre- 

 quent laundering is likely to result. 



Contamination from air. It is difficult to disassoci- 

 ate the contamination arising from the condition of the 

 air from that derived directly from the animal. Barn 

 operations of various kinds result in the production of 

 dust, particularly where dry forage, such as hay or straw, 

 is handled. Where manure is given an opportunity to 

 dry, dust is readily produced, and such material is partic- 

 ularly replete with bacterial life. Some kinds of dust, 

 such as that originating from ground grains, or shavings 

 that may be used for bedding, contain a small amount of 

 bacterial life in comparison with the dust from hay, 

 or other dry fodder. In a dried condition, the slightest 

 movement is apt to dislodge these fine particles, and they 

 float in the air for considerable periods of time. If milk 



