198 SCIENCE AND PRACTICE OF DAIRYING. 



gramme of difference. From the loss of weight thus found the weight of 

 the glass beaker is ascertained by weighing the butter, the percentage of 

 water in the butter is calculated. 



(2) Determination of the Fat. The residue in the beaker is dissolved 

 and detached with a small glass stirrer as perfectly as possible from the 

 bottom of the beaker, washed out with pure ether, free from water, on to 

 a filter, which is fastened in a small funnel over the beaker containing the 

 chief quantity of the fat; the glass beaker and the stirrer are then washed 

 with ether, and the filter and its contents are washed with ether till 

 a few drops of the filtrant show no trace of fat when evaporated on a 

 watch-glass. The ether is then evaporated off, and the filter is dried in an 

 air-bath at 100, cooled in the desiccator, again placed in the air-bath, and 

 after cooling weighed. This is repeated till the weight is constant. 



(3) Determination of the Ash. The residue remaining on the filter is 

 charred along with the filter-paper at a low heat, and after it has been 

 repeatedly boiled with distilled water and filtered it is burned to a white 

 heat. The filtrate is then added in small quantities to the ash in the 

 platinum capsule, placed in the water-bath to dry, and finally is burned 

 along with the filter, with a cover at a moderate heat, allowed to cool, 

 and weighed, the weight of the ash from the two filters being deducted. 

 Since fresh butter contains for the most part very little over -1 per cent of 

 ash, the percentage of chlorine will only be about '003 per cent, and in 

 this way it is easy to arrive at a closely approximate estimation of the 

 percentage of salt in salt butter by a determination of the chlorine in 

 the ash. 



(4) Determination of Proteids. 80 to 100 grams of butter are weighed. 

 The fat, after being perfectly separated from water, is separated from 

 the remaining butter constituents, and is exactly determined in the 

 method described in (1) and (2), descriptive of the water and fat deter- 

 minations. The residue remaining on the filter-paper is then used for 

 the determination of the nitrogen. The proteids are obtained by multi- 

 plying the percentage of nitrogen found by the factor, 6-39. As it is 

 doubtful, especially in the case of old butter and that made from sour 

 cream, whether all the nitrogenous substance belongs to the albuminoid 

 group, the number denoting the proteids may be regarded as a little 

 inexact. 



(5) Determination of the Non-nitrogenous Soluble Organic Bodies (Milk-sugar, 

 Lactic Acid, &c.). If the percentage of water, fat, ash, and proteids have 

 been determined exactly by two duplicate analyses, showing close agree- 

 ment, the sum of the weight of these constituents is deducted from 100, the 

 difference being credited as milk-sugar, lactic acid, &c., or non-nitrogenous 

 soluble organic bodies. The attempt to determine this group of substances 



