CHAPTEE n. 



ON THE DETERMINATION OF THE CON- 

 STITUENTS OF BUTTER. 



The substances mth. which we have to deal in this chapter 

 are water, casein, salt, and fat ; the analysis of the latter 

 being by far the most important point in butter examination, 

 will be specially treated with in another chapter. 



For the determination of the water, two processes may 

 be employed. The first and older method is frequently 

 recommended, but, as may be seen, is only capable of giving 

 approximate results, and more fit for the butter-dealer than for 

 the chemist. It consists in fusing the butter ia a graduated 

 tube, about haK an inch in diameter, and similar to those used 

 for the estimation of cream in milk. The butter-fat separates 

 in consequence of its low specific gravity, the water, salt, and 

 curd sinking to the bottom, and the amount of water being 

 read off on the graduated scale. It is evident that this 

 method is better adapted for the estimation of the fat than 

 of the water. 



The other method, the only reliable and accurate one, con- 

 sists in drying a weighed quantity of butter in a porcelain 

 or platinum dish, tOl aU moisture is driven oiE The drying 

 may be done either on the water-bath, in the air, or on the 

 sand-bath. If on the water- bath, the dish should not be too 



