30 A DAIRY LABORATORY GUIDE 



An illustrative example will show how these 

 formulae operate. Suppose the Q. lactometer read- 

 ing of a sample of milk was 32.5 at 60° F. and the 

 fat reading was 4.2 per cent, what are the solids 

 not fat ? 



Formula= 



3.8 



=S. N. F. .7X4.2=2.94 



2.94+32.S=3S-44 

 35-44-^3-8=9-32+ 

 Formulating the above calculation : 



32.5+2.94 ^g_^^y^ S. N. F. 



9.32+4.2=13.52 total solids. 

 Using formula 2 : 



^=S. N. F. 



32.5+4.2^36.7 



36.7-^4=9.17+% S. N. F. 

 Formulating the above calculation : 



^^=^±^=9.17 S. N. F. 



9.17+4.2=13.37 T. S. 

 Using formula 3 : 



j4L+.2f+.i4=S. N. F. 



32.5^-4=8.12 



.2X4-2=.84 



8.12+.84+. 14=9.10 S. N. F. 



9.10+4.2=13.30 T. S. 

 By modifying Babcock's third formula the total 

 solids may be obtained directly. It is as follows: 



}i L+i.2f+.i4=T. S. 

 Using the above lactometer and fat readings as 

 an illustration, the formula would give the following 

 results : 



32.5^4=8.12 



i.2X4-2=S04 



8.i2+5.04+.i4=i3-30% S. N. F. 



