ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 105 



Now we estimate that at 53 degrees that bacteria increases sixty- 

 fold, at 93 degrees they increase 180 fold, and at 40 degrees bacteria life 

 becomes inactive. Even freezing does not kill them, but this urges the 

 necessity of cooling milk. 



Q. Can I infer that bacteria ceases vegetating at 40? 



A. Remember I am not talking of those that affect meat; some of 

 them reproduce themselves even down to freezing point, and some of them 

 decay, and if meat is imperfect, with that certain kind even to 84, but it 

 takes a long time to do that. The development ranges from 60 to 180. 



Now then, heat, on the other hand, has the same effect as cold. At 

 112 degrees, however, is the best point, for then nearly all bacteria life is 

 killed, except the spore. 1 don'i want you to understand that that in- 

 cludes all bacteria; this pertains to milk. The spore develops slower, 

 and does not do so much damage. 



Now when we kill all bacteria life, either spore or active germs, we 

 call that substance sterilized. We don't apply this directly to milk very 

 often. Sterilized milk has change d it composition to a great extent for 

 that reason it is impracticable; it is not a practicable business. But 

 where sterilization becomes practicable is in cleaning dairying utensils. 

 Mere water and elbow grease does not clean milk pails. We have to 

 sterilize them in order to have them germ-free, and then the spore is de- 

 veloped if brought to a favorable temperature, but the active bacteria 

 that does the filthy work right away is killed by boiling. Hence, it is 

 very essential that we should sterilize our utensils, by subjecting them 

 to steam heat, or, if no steam, boil them in boiling water from 30 to 40 

 minutes. Give them a good long boiling. It is very necessary mat we 

 should clean our utensils first with soap and water, to get rid of the scum 

 and germs, for if we do not do that we find that the albumen coagulates 

 and adheres to the tin, and those who have cleaned utensils in which 

 they have boiled milk first, find it is a very difiicult task. For this rea- 

 son, we should have the utensils free from corners as much as possible. 



Here is a picture of a milk pail that is made improperly and which 

 has sharp corners. If we do not sterilize that pail we have a lurking 



