MILK 



[vn 



avoid them. The colder portion of the milk, being 

 of greater specific gravity, sinks to the foot ; and the 

 warmer portion, being lighter, rises to the top. In 

 this way the collection of fatty globules on the 

 surface is disturbed and impeded. The descending 



FIG. 17. DROP OF CREAM (undiluted) fifteen minutes after churning 

 has begun. (Kirchner.) 



currents carry away more fat with them from the 

 cream layer than the ascending currents bring back 

 to the surface. It is only after the entire mass of 

 the milk assumes the same temperature as the sur- 

 rounding air, and when currents due to temperature 

 are no longer induced, that the fatty globules can 



