THE PASTEURIZATION OF MILK 



be left in the can renders the condition favorable 

 for the growth of bacteria which have escaped de- 

 struction, and second, because cans which are not 

 dry are much more likely to become rusty. Rusty 

 cans are hard to clean, and frequently become a 

 loss to the owner because they soon wear out and 

 are discarded. One form of can rinser, steamer 

 and dryer is rather ingeniously arranged. The ex- 

 haust steam, after having been used to operate a 

 turbine-driven fan, is employed to sterilize the 

 cans. The steam pipe which supplies the fan tur- 

 bine passes in coils through an air chamber, and 

 thus is used to heat the air which is forced by the 

 fan into the cans after they have been sterilized. 

 There is thus a very economical use of the steam, 

 and the apparatus is also very compact. 



Cans, after they have been treated, should be 

 stored in an inverted position until they are used 

 for containing milk. If, however, they are thor- 

 oughly dry, there seems to be no objection if the 

 covers are tightly placed upon them and they are 

 then stored without inverting. 



In determining what test to apply in order to 

 ascertain whether or not milk containers are ster- 

 ile, or sufficiently so for practical purposes, it 

 174 



