2 ANALYSIS AND ADULTEEATIONS OP BUTTER. 



Cream contains, besides large quantities of fat and water, 

 notable proportions of casein and of sugar of milk. The rela- 

 tive amounts of these ingredients vary considerably, according 

 to the time allowed for the separation of the cream, the 

 temperature, the quality of the mUk, and other circumstances, 

 but genuine creams of good quality, such as have been 

 analysed by HassaU with the subjoined results, yield not less 

 than 30 per cent, of pure fat. 



Samples 1-3 were purchased of milkmen, 4-6 being 

 obtained direct from the dairy. 



100-00 100-00 100-00 100-00 100-00 99-95 

 By violent agitation in a churn or any other suitable vessel 

 the oil globules of the cream conglomerate for the most part, 

 and uniting form a fatty mass, which invariably contains small 

 quantities of the other constituents of the cream, which can- 

 not be removed by mechanical means, if we except the small 

 amount of sugar of milk which may be washed off. This 

 mass, to which some salt is generally added during the 

 process of preparation, is the butter of commerce. 



Butter may vary much in colour and flavour, even when 

 quite fresh and sweet, these qualities being governed by a 

 great variety of circumstances. Thus the flavour of the food 

 of the cow in many cases may be distinctly perceived in 

 the fresh butter, while the colour ranges, according to 

 season and food, from a rich to a very pale yellow. 



Carefully prepared butter is homogeneous throughout its 

 mass, pellucid in appearance, and free from superfluous water. 

 It soon loses its sweet odour and taste, owing to the partial 



