ANALYTIC DATA 7 



averages being deduced by analysis of lo samples. 

 The following data are selected from this table.- 

 For exiplanation of the figures in the last column 

 see page 42. 



From these figures Lythgoe derives the rule 

 that differences in proportion of solids not fat in 

 unadulterated milks are principally due to dif- 

 ferences in the amount of proteins. Lactose and 

 ash are fairly constant. On these facts depend 

 recently introduced methods of detecting water- 

 ing milk, as will be pointed out later. 



Colostnun. — ^This is the secretion in the early 

 stages of lactation, and differs from ordinary 

 milk. It contains characteristic structures, 

 known as colostrum corpuscles, and usually 

 contains much less fat than fully developed 

 milk, but a larger proportion of proteins. Colo- 

 strum coagulates on boiling. Lactose is in small 

 amount. 



