40 Dairy Bacteriology. 



ically eliminated, but most of the cleaning processes fail 

 to destroy the germ life in these utensils. 



In rinsing, washing, or even scalding, the water is not 

 applied at a sufficiently high temperature to destroy ef- 

 fectively the bacteria. These processes are primarily 

 used for the removal of dirt and other matter. To facil- 

 itate such removal, washing powders of various kinds 

 are frequently employed ; some of these possess consider- 

 able disinfecting action. All utensils after cleansing 

 should be thoroughly rinsed in clean, hot water. Even 

 where no further treatment is given, a careful cleaning 

 may so reduce the germ content on the inner surface of 

 utensil as to render contamination therefrom relatively 

 unimportant. Most of the contamination in a well 

 cleaned utensil comes from the cracks and angles, which 

 permit of the collection of the dirt. If these are prop- 

 erly attended to, thorough cleaning and rinsing alone 

 will accomplish much. 



To exert an actual germ-destroying effect 'on the bac- 

 terial content of the utensil, resort must be had to boil- 

 ing or steaming. To treat utensils so as to render them 

 wholly germ-free would be impractical under ordinary 

 commercial conditions, as it would consume too much 

 time, although with proper apparatus, this process is 

 not impossible, but it is well within the limits of prac- 

 ticability in factory treatment to apply steam for a short 

 period of time. Where cans, pails and such utensils, 

 are steamed for a minute or so after being thoroughly 

 cleaned, the germ content is greatly reduced. In a series 

 of tests by Harrison, the germ content of a set of cans 

 cleaned in an ordinary way was 442,000 bacteria per 

 cubic centimeter in 100 cubic centimeters of wash water ; 

 in a set washed in tepid water and then scalded the 

 best farm practice it was 54,000 per cubic centimeter, 



