36 Milk and Its Products. 



ous chemists, a considerable number of which give 

 very accurate results. Chief among these methods 

 for determining fat and total solids are the Babcock 

 asbestos method and the Adams paper -coil method. 

 In order that these determinations may be made 

 with accuracy, balances of extreme delicacy, and 

 apparatus more or less complicated and requiring 

 considerable skill in its manipulation, are necessary, 

 so that for ordinary commercial purposes they are 

 practically out of reach. 



History of milk tests. — Although consumers of 

 milk had felt for a long time the necessity of 

 some means of protection against dishonest dealers, 

 it was not until the development of the factory sys- 

 tem of manufacturing cheese (1850) and butter 

 (1870) that some means of easily determining the 

 composition of milk, particularly as to fat content, 

 became important to both producers and manufac- 

 turers. From that time on various methods have 

 been devised, from the simple expedient of raising 

 the cream in a small sample of milk in a graduated 

 glass to apparatuses almost as complicated and 

 difficult of manipulation as the gravimetric methods 

 themselves. 



Cream gauges. — The simplest and one of the 

 earliest methods used to determine the quality of 

 milk is to set a small portion of it under such con- 

 ditions that the cream would be thoroughly thrown 

 to the surface and easily measured. These were 

 known as cream glasses, cream gauges, or cream- 

 ometers, and to a certain extent served a useful pur- 



