202 Effect of Chemicals. 



compete with the present method of steaming milk bottles in order 

 to partially sterilize them. 



From these experiments it appears doubtful if ultra-violet 

 rays can be used on a commercial scale to replace the process of 

 pasteurization. However, it may be possible to use the rays, in 

 combination with pasteurization, in the preparation of a special 

 milk with a low bacterial count, provided there is a demand for 

 such milk in limited amounts for the use of infants and 

 invalids. Trans.] 



4. Other methods of preserving milk are its saturation with 

 carbonic acid under strong pressure, its ozonisation, and its sterili- 

 zation with electrical currents. 



The carbonization recommended by Hoffmann, van Slyke, and 

 Bosword, the ozonisation advised by Dorn, and finally the steriliza- 

 tion through alternating electric currents of high tension recom- 

 mended by Guarini and Samarini have not yet attained any prac- 

 tical significance. 



The best means of imparting keeping qualities to milk are 

 cleanliness in its procurance; the only method of preservation 

 which should be generally permitted for milk is proper cooling. 



This concludes the theoretical consideration of milk. In the 

 following chapter the method of control of milk in general will be 

 discussed, and finally the method of milk examination will be 

 taken up with emphasis on the points which appear especially 

 important in the examination of market milk and for the ex- 

 aminations of individual samples of milk. 



