16 THE CONTAMINATION OF MILK. 



cooled by water. There may be a water leak in the apparatus, 

 causing contamination from that source. Milk cans are fre- 

 quently stood in tanks of water, for cooling, and splashing 

 may cause water to reach the milk. The practice of adulter- 

 ating milk with water is common enough to deserve note as a 

 source of contamination. Bergey (8) has given figures show- 

 ing the increase in the bacteria of milk at different stages in 

 handling, derived from various utensils. 



Bottling milk. The filling of milk bottles in the larger dairies 

 is done rapidly by the use of a bottling machine. In some 

 cases a machine is used which also places the paper caps in 

 position. This is desirable, from a hygienic point of view, 

 because it eliminates the dangers associated with the handling 

 of the paper caps when this is done by a man. When the 

 machine is used, the caps are sterilized before using. When 

 bottles are capped by hand danger from contamination by the 

 workman may be minimized by the use of a special copper 

 tube with a slit on two sides. The caps are stacked in this 

 tube when sterilized, after which they are removed and used 

 by touching the edges only (Ref. 8, Chap. IX). 



Milk room. The cooling and subsequent manipulation of 

 the milk should be carried on under conditions as free as pos- 

 sible from the influence of dusty air. A room or building sep- 

 arate from the stable should be provided for the purpose. A 

 cement floor, screened windows and ease of cleaning are desir- 

 able features of such a structure. In the best dairies admit- 

 tance to the milk room is denied to the milker and even visit- 

 ors. Elaborate precautions are taken to prevent contamination 

 of the milk during straining, etc., even the air being freed 

 from bacteria before entering the room through the ventilating 

 system. 



Delivery of milk. Bacteriological considerations lead to the 

 conclusion that delivery in sterile bottles, filled at the dairy, 

 offers the least possibility of contamination in transit. But 

 the milk bottles must be cleaned and heated well before use, 

 if for no other reason than the fact that milk bottles are put to 

 disgusting uses in some households. Bottled milk is not always 

 what it should be, as for instance when the driver fills a dirty 



