CLEANLINESS IN BUTTER AND CHEESE FACTORIES. 115 



especially in frame buildings, that the layer of cement has 

 loosened along the walls and the crack thus formed has 

 been filled with a dark, moist mass, containing filth of all 

 kinds, and of course bacteria without number. Cement 

 floors are furthermore eaten up by lactic acid (sour milk). 

 On account of all this they cannot be recommended in 

 creameries where large quantities of water are used for rins- 

 ing. The same holds true in regard to floors of limestone 

 slabs; the slabs have rarely a sufficiently smooth surface, 

 and they often cannot be laid close up to each other. The 

 custom to lay these slabs as closely as possible up to one 

 another in loose sand, which is practised in many places 

 especially in foreign countries hoping that the interstices 

 soon will be filled with sand and dirt, must of course be 

 absolutely condemned, for infection hotbeds are thereby 

 created all over the floor. It is a better practice to imbed 

 these slabs in cement so that the interstices become filled 

 therewith. I have, however, observed in several creameries 

 where such floors are found that the cement between the 

 slabs is soon eaten up and gives way to large gaping cracks, 

 that gradually fill up with a sticky, filthy mass. Wooden 

 floors are still more to be rejected. Through the abundant 

 washing they are kept constantly moist and are apt to 

 soften and swell, after a while allowing water mixed with 

 milk to run through into the ground, where a luxurious 

 and injurious mould and bacteria growth is produced in the 

 dark, giving off bad odors and forming a constantly threaten- 

 ing source of infection for the milk. 



The only creamery-floor which in my experience fills 

 the demands just given, and thus allows of a flooding of 

 the floor, are those made of a genuine, natural asphalt. 

 Such a floor is firm, impervious to water, will not crack, is 



