212 MILK GLOBULE AS AFFECTED BY GRATITT. 



Experiment I. 



Three drops of milk were taken from a vessel con- 

 taining milk wliich had been undisturbed for fourteen 

 hours : ^ — 



m drop. Top layer cream A.veraf;e size of globule, 6120". 



2d " Lower laj'er cream Average size of globule, 6640". 



3J " Six inches below surface Average size of globule, 8260". 



Should the globules which occur at these difl'erent 

 depths ])Q churned, it would be found that the differ- 

 ent la\ers would require a greater or less exposure 

 to the churning action to produce butter, and the 

 butter would vary somewhat in quality in each churn- 

 ing. This may be readily veritied by skimming a 

 vessel of milk at intervals, and churning the cream 

 of each skimming by itself. 



The process of churning consists in breaking the 

 covering of the milk globule and collecting the re- 

 leased fat into lumps. This breakage seems usually 

 to occur through friction ; and the ease with which 

 it occurs is determined in part by the toughness 

 of the investment, and in part by the size of the 

 globules. 



In general, the time required for churning milk or 

 cream from the same breed, into butter, has a close 

 relation to the size of the globule. 



Experiment II. 



Three Jersey cows, on similar feed, yielding same 

 amount of milk. The milk of the same milking, set 



The si^'ii " BigniHcs tlis of an Inch To illuslra'c : these figures are to bo 

 read l-612uth of an inch, l-6«40th of an inch, etc. 



