64 A New Dairy Industry. 



ftill vital energies, how much greater must then be 

 the possibility that these bacteria will in another, 

 their endurate form, be able to resist such higher 

 temperatures ? We know, in fact, quite a number of 

 bacteria whose endurate forms, the spores, are able 

 to endure such intensive heat as would at once kill 

 all other organic life. The baccillus subtilis has 

 been cooked for two hours and a half, consecutively, 

 at 212 and not lost its power to germinate, and an- 

 other investigator found that this ironclad baccillus 

 could be killed only at 240 of heat. Globig found 

 a baccillus living on the potato, the " red potato bac- 

 cillus," the spores of which could be pronounced dead 

 only after having remained in steam of 212 for six 

 hours, and in steam under pressure at 235 the same 

 spores were yet alive after forty-five minutes. 



It will, therefore, easily be understood that in a 

 process like the pasteurizing, which seldom exceeds 

 100 to 175, there very frequently remain live bac- 

 teria and spores in milk, which are sure to spoil it 

 after a longer or shorter time. The desire, however, 

 to give milk keeping qualities, not only for days but 

 for weeks and months, is an urgent one, and, there- 

 fore, all efforts have been concentrated to destroy all 

 bacteria by the application of heat above 212, and 

 thereby to reach the desired keeping quality. Re- 

 viewing the observations hitherto enumerated of the 

 temperatures at which the spores of several of the 

 more resistant kinds of bacteria may be killed, we 

 see that milk which contains, for instance, the wide- 



