[302 



PART VIII 



ANAL YSIS OF DAIR Y PROD UCE 



MILK ANALYSIS 



Milk is an exceedingly complex substance. To separate 

 and estimate its various component parts entails a long and 

 difficult series of operations. In practice, however, it is found 

 sufficient to make the following determinations : 



Specific gravity ; 



Fat; 



Total solids ; 



Ash. 



Sometimes this analysis is carried out with the object of 

 discovering whether the milk has been diluted with water or 

 reduced in quality by the removal of cream j but the true com- 

 mercial analysis is directed towards discovering the value of 

 the milk for dairy purposes. Thus the chemist of the Aylesbury 

 Dairy Company analyses over ten thousand samples yearly, not 

 to detect fraud, but to see that the milk supplied to the public 

 reaches a certain standard of richness. 



302. Specific Gravity. — This is very readily determined 

 by means of a hydrometer such as is used for taking the S.G. 

 of turnip juice. The lactometer is a modified form of hydro- 

 meter, marked off in degrees. A difference of one degree 

 represents a difference in specific gravity of *ooi. The gradu- 



