3<> A yezc Dairy Industry. 



name it is sold under, can conscientiously guarantee 

 the pureness and healthfulness of his milk unless he 

 has had personal supervision and control of the physi- 

 cal condition of the cows, the food they have eaten 

 and the treatment thev have received. 



flbetboos of preserving fllMlft. 



As we have seen in the foregoing, the changes in 

 milk, more especially its curdling, are due to the 

 action of bacteria (and to some other fungus spores), 

 we shall, therefore, succeed in preserving it if we can 

 either defer the action of the bacteria or remove them 

 entirely. Both methods have been tried for some 

 time. Efforts have been made to prevent the im- 

 pending souring by adding chemicals, the curdling 

 by so-called preservalines, and also to counteract, by 

 refrigerating, these phases of commencing decompo- 

 sition ; but of late all efforts have been directed to- 

 wards killing the bacteria themselves through the 

 application of heat, so as to secure in this manner the 

 keeping qualities of milk even for a longer period. 



