128 



PRACTICAL DAIRY BACTERIOLOGY 



them intelligently, however, for a careless milker can obtain 

 as bad results from a covered pail as from any other. In their 

 use special attention must be given to the cloths used for 

 strainers. These must be sterilized daily by washing and boil- 

 ing. It is sometimes customary to change the strainer cloth for 

 a fresh one between the milking of each two cows. Strainers 



FIG. 52 COVERED MILK PAILS (c.URLERS AND STADTMULLERS) 



made of bolting cloth, Irish linen, or flannel are the best, and 

 these may be used over and over again with the proper washing. 

 If absorbent cotton is used for a strainer, it must be thrown 

 away after the milking. 



Milking Machines. A still more recent means of reducing 

 contamination is by machines designed to convey the milk 

 directly from the cow's teat to closed sterilized milk cans, with- 

 out allowing it to come into contact with the air, or exposing 

 it to contamination with dirt. 1 These milking machines consist 

 of rubber tubes ending in special cups for attachment to the 

 teats of the cow and connected at the other end with large cans, 

 which can be sterilized. (Fig. 53.) The cans are connected 

 with a vacuum system of tubes, and at the point where the 

 rubber tubes are attached to the can there is a mechanical device 



!Lane and Stocking. Bui. 92, Bu. An. Ind., 1907. 



