14 THE CONTAMINATION OF MILK. 



tory as by the other method tested by him. When the oper- 

 ator is in a hurry, and shortens the exposure down to three 

 seconds, the efficiency of the method is open to question. The 

 machine in which bottles, in an inverted position, are passed 



fig. 4. Sterilizer containing racks for Jwlding bottles. 



over steam jets, likewise does poor work, unless its speed is so 

 slackened as to reduce its rated output (54). Boiler scale com- 

 pounds, or oil in the feed water, may so taint the steam that 

 an objectionable odor will be transmitted to the cans or bottles 

 and thence to the milk or cream. 



