122 BACTERIA IN DAILY LIFE 



Some of the most easily preventable, but at the 

 same time most aggressively assertive, dairy 

 troubles are undoubtedly directly dependent upon 

 the conduct of milking operations. 



In the first place, the cow itself is only too 

 frequently in an uncleanly condition, and as its 

 coat offers exceptional facilities for the harbouring 

 of dust and dirt, the danger of foreign particles 

 falling into the milk is always present unless 

 precautions are taken to negative, or at least mini- 

 mise, all such chances of contamination. 



Professor H. L. Russell, of the Wisconsin 

 Agricultural Experiment Station, cites in his 

 little volume on Dairy Bacteriology an instructive 

 experiment which brings home very forcibly the 

 importance of such precautions. A cow pastured 

 in a meadow was selected for the experiment, and 

 the milking was done out of doors, so as to elimin- 

 ate as far as possible any intrusion of disturbing 

 foreign factors into the experiment, such as the 

 access of microbes from the air in the milking- 

 shed. The cow was first partially milked without 

 any precautions whatever being taken, and during 

 the process a small glass dish containing a layer of 

 sterile nutrient gelatine was exposed for one 

 minute beneath the animal's body, in close 

 proximity to the milk-pail. The milking was 

 then interrupted, and before being resumed the 



