94 



Testing Milk and Its Products. 



which it replaces is equal to the weight 

 of the body. It will sink further into a 

 light liquid than into a heavy one, be- 

 cause a larger volume of the former will 

 be required to equal the weignt of the 

 body. A lactometer will therefore sink 

 deeper into milk of a low specific grav- 

 ity than into milk of a high specific 

 gravity. 



The scale of the Quevenne lactometer 

 is marked at 15 and 40, and divided into 

 25 equal parts, with figures at each five 

 divisions of the scale. The single divis- 

 ions are called degrees. The 15 degree 

 mark is placed at the point to which the 

 lactometer will sink when lowered into a 

 liquid of a specific gravity of 1.015, and 

 the 40 degree mark at the point to which 

 it will sink when placed in a liquid of a 

 specific gravity of 1.040. The specific 

 gravity is changed to lactometer degrees 

 by multiplying by 1000 and subtracting 

 1000 from the product. 



Example: Given, the specific gravity of a 

 sample of milk is 1.0345; corresponding lacto- 

 meter degree, 1.0345x1000-1000=34.5. 



Conversely, if the lactometer degree 

 is known, the corresponding specific 

 gravity is found by dividing by 1000 

 and adding 1 to the quotient (34. 5 ~ 1000 

 = .0345; .0345-j-l = 1.0345). mder(ii2). 



FIG. 38 



Quevenne 

 a tin c"f 



