IO4 



MILK AND DAIRY PRODUCTS PART 



Halenke and Moslinger have worked out the following 

 simplified formula : 



/ + 8/5 

 0-8 



t - 



where s denotes lactometer degrees, not the specific gravity. 



The safest and most generally used method for proving the 

 addition of water to milk is to determine the specific gravity of 

 the milk, the fat, and the total solids. This last is obtained 

 most conveniently by using Fleischmann's formula, which, it 

 may be noted, applies only to fresh milk. When the milk is 

 old very considerable differences are found between the calcu- 

 lated and the real 

 amounts of total 

 solids. 



Ordinary normal 

 mixed milk has only 

 very exceptionally a 

 specific gravity below 

 1-029 (equal to 29 of 

 the lactometer). If 

 water is added to the 

 milk the specific 

 gravity naturally 

 sinks, the fall being 

 considerable, as much 

 as three lactometer 

 degrees, for each 10 

 per cent, of added 

 water. If, for ex- 

 ample, normal milk 

 has a density of 30'6 lactometer degrees, it would only have 



27 degrees after the addition of 10 per cent, of water, and 24'5 

 degrees after the addition of 20 per cent. A specific gravity of 



28 degrees, consequently makes a sample of milk suspicious, and 

 if the specific gravity is less than the above figure, water has 

 certainly been added. If, therefore, the lactometer indicates the 

 addition of water, the percentage of fat in the milk should be 

 determined by some reliable method, and then the amount of 

 total solids can be ascertained with the help of Table VII. in the 



FIG. 50. Ackermann's Apparatus for Calculating 

 the Total Solids. 



