100 FOODS AND FOOD ADULTERANTS. 



ing the fat remains dissolved in the alkaline milk and this part of the 

 ether contains no fat. The result is that the ethereal solution of the fat 

 contains more of this substance than it otherwise would if the whole 

 of the ether was separated. 



Wolff has therefore proposed the following changes in the quantities 

 of the reagents to be used and claims thereby to have obtained results 

 which wholly agree with the estimations of fat by weight. For 50ec. of 

 milk he proposes 3cc. of potash lye of 1.145 specific gravity and 54ec. 

 of the aqueous ether. 



Liebermann, however, in a review of the methods proposed by Wolff, 

 maintains that his original method gives entirely reliable results. 



FLEISCHMAN AND MOKGEN'S METHOD. 2 



Fleischmau and Morgen describe a method of determining fat in milk 

 when the specific gravity and total solids are known. 

 Fleischmau 3 gives a more detailed study of this method. 

 The formulae for the calculations are as follows : 



(1) < = 1. 



(2) /=0.833- 2 . 22 



In these formula t=per cent, total solids; /=per cent, fat in milk j 

 S=specific gravity of the milk at 15 O. 

 The above formulae may be simplified by putting 



d=100S-100. 



Tables are given to aid in the calculation of the results. By these 

 formula when either the per cent, of fat or the total solids is known the 

 other can be calculated with a high degree of accuracy. 



ESTIMATION BY VOLUME OF CREAM. 



The determination of the volume of cream gives a rough approxima- 

 tion of the percentage of fat in the milk. 



The methods generally in use are based on the natural separation of 

 the fat globules on standing and the estimation of the volume thereof 

 in a graduated cylinder. 



The creamometer of Chevalier 4 will serve as a type of all apparatus 

 of this class. It is a cylinder 20cm. high and 40cm. diameter. The scale 



1 Pharm. Centralh., vol. 24, p. 435; Zeit. Anal. Chem.,1884, p. 87. 



3 Jour. Landw., 1882, pp. 293-301. 



3 Jour. Landw., 1885, pp. 251 et seq. 



Becke, Milclipriifunjis-Methoden, p. 40. 



