COOLING AND ABRATION 41 



common, practice. The best of natural- ice contains dirt 

 and bacteria. Even ice made by mechanical means from 

 distilled water often contains considerable quantities of 

 impurities. Ice also is an adulterant just as much as 

 water. In case of cream cooled with ice the body is unr 

 satisfactory, even if the cream contains the required 

 amount of fat. 



