40 DAIRY CHEMISTRY 



water lowers the gravity, and the removal of the fat 

 raises it, so that milk which has been both skimmed 

 and watered may have the same gravity as normal 

 milk. This double fraud, however, is easily detected 

 when the Babcock test is used jointly with the lac- 

 tometer. 



47. Calculation of Solids in Milk. The proportion 

 in which the various solids are present in milk 

 directly influences both the lactometer readings and 

 the results obtained with the Babcock test. The 

 solids not fat (casein, albumin, sugar, and ash) in- 

 crease uniformly at the rate of .25 per cent for each 

 lactometer degree, and .02 of a per cent for each per 

 cent of fat. This general relationship between the 

 fat in milk and the solids not fat has been studied by 

 a number of investigators, notably Richmond, Fleisch- 

 mann, and Babcock, who have proposed various for- 

 mulas for the determination of the solids in milk. 

 Babcock's formula is as follows : 



Solids 



When this formula is applied to a large number of 

 observations, it will be noted that u the solids not 

 fat increase uniformly at the rate of .25 per cent for 

 each lactometer degree and .02 per cent for each 

 per cent of fat." This is also practically the basis 

 of Hehner and Richmond's formula. They found 

 that the calculated solids were uniformly about .14 

 of a per cent less than those obtained by chemical 



