116 Testing Milk and Its Products. 



Fat abstracted=legal standard for fat — f, . . (I) 

 f being the per cent, of fat in the suspected sample. 



2. The following formula will give the per cent, of 



fat abstracted, calculated on the total quantity of fat 



originally found in the milk: 



f XlOO 

 legal standard for fat 



b. Wateri)ig.—It a sample is watered, the calcula- 

 tion is most conveniently based on the percentage of 

 solids not fat in the milk. The percentage adulteration 

 may be expressed either on basis of the amount of 

 water present in the adulterated milk, or the amount of 

 water added to the original milk: 



1. Percent, of foreign (extraneotis) water in the adul- 

 terated millc =100-, ^-- -, ^/„^°°~,.-j TT^Cni) 



legal standard for solids not tat 



S being the per cent, of solids not fat in the suspected 

 sample. 



Example: A sample of milk contains 7.5 per cent, solids not 

 fat; if the legal standard for solids not fat is 9 per cent., then 

 JOO — 7. Sill no ^—-^Qj^ shows the per cent, of extraneous water 

 in the milk. 



2. Watering of milk may also be expressed in per 

 cent, of water added to the original milk, by formula IV : 



Per cent, of water added to the original milk 



lOOV leg. stand, for sol. not fat 

 = — -- g -100 (IV) 



In the example given above, J5?5L — 100^20 per cent 

 of water was added to the original milk. 



c. Watering and skimming. — If a sample has been 

 both watered and skimmed, the extent of watering is 



