u6 



MILK 



[VH 



to coalesce by churning the milk, the fat globules 

 being converted from a liquid condition to a solid 

 one by the violent impact which they thus experience 

 (Figs. 15, 16, 17, and 18, pp. 116-119). Butter can 

 be obtained by directly churning the milk ; but it 



FIG. 15. MICROSCOPICAL APPEARANCE OF A DROP OF MILK, containing 

 3-6 per cent of fat, magnified 670 times. (Kirchner.) 



has always been regarded as more convenient to first 

 cream the milk, and thus effect a concentration of the 

 globules before churning. In the first place, there- 

 fore, it may be well to consider what the conditions 

 are which regulate the separation of the fat. 



Conditions influencing Separation of Fat. A 



