CLEANLINESS IN BUTTER AND CHEESE FACTORIES. 131 



as a standard for good drinking and well-water that it 

 must not contain more than 500 bacteria capable of de- 

 velopment per cubic centimeter. Plagge and Proskauer 

 consider the upper limit 300 per cubic centimeter, while 

 others place the standard still lower. 



The milk and its products often come into most inti- 

 mate contact with water in the factory. Small portions of 

 water will remain in every can, in the churn, in vats, on 

 the worker, etc., so that the milk throughout its handling 

 and manufacturing may be infected by bacteria found in 

 the water. It will not therefore be surprising that we have 

 dwelt at length on the importance of the quality of the 

 water in the factory and the care of the well. 



Purification of Water. It would of course be preferable 

 to entirely remove the bacteria from the water to be used 

 in the factory, but this would be too expensive. Breyer's 

 " micro-membrane filter " is recommended by several parties 

 for use in factories and is said to deliver sufficient water. 

 The water is in this apparatus filtered through specially 

 prepared asbestos disks. Chamberland's filtering apparatus 

 also performs this cleaning process very well, but the ca- 

 pacity of the apparatus is generally much too small to be 

 adapted to factory use. At all events it is so expensive to 

 remove bacteria from the water by such apparatus that it 

 will hardly be generally adopted in factories. 



It is, however, the duty of every factory-man to keep 

 the water in the factory as pure and free from bacteria as 

 possible. He must first of all see to it that the well fulfils 

 fair demands in regard to the conditions mentioned, and 

 that the water is always used as soon as pumped. By 

 standing in the warm factory a far greater number of bac- 

 teria may develop in the same than was originally found in 



