158 



NORMAL MILK : ITS ADULTERATIONS, ETC. 



TABLE XXVIII. — Solids in Milk of Different Breeds of 

 Cattle (Bell). 



Variations of Fat in Different Ch-urns. — When milk is 

 divided into portions, as is the case when it has to be transported 

 by railway, considerable variations in fat are sometimes noticed. 

 As examples, the following analyses may be quoted : — 



TABLE XXIX. 



Series I. 



Senes II. 



Specific gravity, 



Total soUdg, 



Fat, . 



Solids not fat, , 



1-0345 



p. ct. 



11-28 



2-10 



910 



1 -0340 

 p. ct. 



11-66 

 2-50 

 9-16 



10320 



p. ct. 



1416 



5-10 

 9 06 



1-0325 

 p. ct. 

 1122 



2-60 



8-62 



1-0320 



p. ct. 



12-42 



3-70 



8-72 



1 ObiO 



p. ct. 

 13-42 



4-80 

 8-02 



Seasonal and Monthly Variations. — Distinct variations 

 according to season are found ; these will be shown by Table 

 XXX., which gives the mean monthly averages of milk for the 

 past seventeen years. 



The year, roughly speaking, can be divided into four periods : — 



(1) November, December, and January ; the milk is rich, both 

 in fat and solids not fat. 



(2) February, March, and April ; the solids not fat do not 

 show appreciable diminution, but the fat becomes less in quality. 



(3) May, June, July, and August ; the fat is low, though there 

 is a tendency to rise at the end of the period. In July and 

 August the solids not fat are below the average. 



(4) September and October ; an improvement in quality both 

 in fat and solids not fat is noticed. 



These periods correspond approximately to the seasons; 

 winter milk is of very good quality, while summer milk is the 

 poorest ; the spring and autumn are transition periods. 



The quality varies in an inverse ratio to the quantity yielded. 



