30 A DAIRY LABORATORY GUIDE 



An illustrative example will show how these 

 formulas 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= 



I- ^'=S. N. F. .7X4-2=2.94 

 2.94+32.5=3544 

 35.44-^-3•8=9•32+ 

 Formulating the above calculation : 



SM±^=g.^2% 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-i7+% 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.i2+.84+.i4=9.io S. N. F. 

 9.io+4.2=i3.30 T. S. 

 By modifying Babcock's third formula the total 

 solids may be obtained directly. It is as follows : 

 % 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.i2 



1. 2X4.2=5.04 

 8.i2+5.04+.i4=i3.30% T. S. 



