Calculation of Milk Solids. 229 



the aid of the specific gravity and the obtained fat content. 



d=percentage of solids=i/> X f + 2.665 X - In this 



s 



equation f=fat content and s=specific gravity. 



Fleisclimann has prepared two tables for the values of y^Xf 



and for the value of 2,665 X ' for the specific gravity 



S 



from 1,028 to 1,0369 and for 2.5% to 5.49% of fat, so that through 

 simple addition of the determined values, the respective content 

 of solids can be established. 



Still simpler is the calculation of the solids by Ackermann's 

 "slide-ruler," which consists of two disks united at the turning 

 point and which slide against each other. The larger of these 

 contains the numbers for the solids and fat contents, while the 

 smaller has the numbers for the specific gravity. By turning the 

 small disk the established specific gravity number and the fat con- 

 tent number of the tested sample are placed opposite each other. 

 An indicator fastened to the inside disk points to the amount of 

 the total solids. 



The amount of fat-free solids is obtained by subtracting the 

 percentage of fat from the percentage of total solids. This is an 

 important factor in suspected cases of adulteration. Marked dif- 

 ferences are the result of artificial influences but in individual 

 samples the difference may be due to natural fluctuations. 



Milk with a high fat content has as a rule more fat-free solids. 

 The milk of cows of the highlands has more fat-free solids than 

 the milk of cows from the lowlands. 



According to Fleisclimann, it should be noted that the fluctua- 

 tions of the different values indicated herein, vary in the different 

 milking periods as compared with the annual average. These 

 fluctuations may amount to: 



10% in the lactodensimeter reading (specific gravity). 



30% in the fat content. 



14% in the total solids. 



10% in the fat-free solids. 



According to Fleisclimann, the fat-free solids do not fall below 

 7.9%, and the specific gravity of the total solid matter (m) which 

 may be determined by the following formula : 



s X d 



s X d 100s + 100 



exceeds only exceptionally 1.4 and is usually 1.31 to 1.36. 



Excepting the milk of individual cows or that of a few cows, 

 according to the agreement of German food chemists, the presence 

 of adulteration is established as follows: 



1. Adulteration with water when the specific gravity of the 



