124 ILLINOIS DAIRYMEN'S ASSOCIATION. 



The ordinary cleaning that is given to pails, cans, strainers, etc., 

 takes out only a portion of bacteria. Just to the extent that carelessness 

 prevails in this part of the dairy work, just to that extent will these 

 utensils contain a larger number of organisms. The k#nd of utensils has 

 considerable to do with the ease with which they are cleaned. Wooden 

 pails are to be avoided. Tinware is now so generally used that but little 

 need be said as to other kinds of vessels, but much of the tinware now 

 on the market is so imperfectly constructed as to shelter germ life. The 

 sharp re-entering angles to be noted in pails, and the open seams in the 

 sides, are harbors of refuge to the many bacillus in his fight for existence. 



What the cans are used for will also to some extent determine the 

 kind of organism found in the same. If one uses the same set of cans to 

 carry home the by-products of the factory— fluids known to be rich in 

 bacteria and generaly in an advanced state of fermentation — then it is not 

 surprising that tainted milks will often be the rule. Too often the cans 

 are imperfectly cleaned at home and the inevitable result is an ''off" milk 

 the next day. The prevalence of gas in the milk delivered to factories 

 making Swiss cheese, an industry that is very important with us in Wis- 

 consin, is entirely accounted for is this way. 



A purely practical experiment of storing milk under the same condi- 

 tions in sterile and unsterile cans will teach any one the value of this 

 point. Such milks kept in cans as ordinarily cleaned but not sterilized 

 will sour a number of hours sooner than one kept covered in a steamed 

 pail. The number of organisms in the two milks will always vary— that 

 in the sterile pail containing less. The germ content of cans and pails 

 may also be determined in another way by rinsing out the vessel with a 

 known quantity of sterile water and then determining the number of 

 organisms in the same. The following data on several pails so treated 

 shows how many bacteria remain in the pail: 



Pail No. 1 -First washing 7,388,900 



— Second washing 157,000 



— Third washing 5,800 



7,551,700 



