ON MILK AND MILK-TESTING 73 



By referring to the table given in answer to ques- 

 tions on page 70, it appears that milk haying 8.85 

 per cent of solids not fat should contain 4.5 per cent 

 of fat. 



4.5 — 3=1.5 per cent of fat missing. 



i-5^4.5=-3333X 100=33.33 per cent of the fat re- 

 moved by skimming, 



How may one detect when milk has been skimmed 

 and watered? 

 Milk has been skimmed and watered if the per- 

 centage of all the solid constituents are reduced and 

 the per cent of fat is reduced to a much greater 

 extent than the other solids. 



If a sample of milk contains 2.8 per cent of fat and 

 8.2 per cent of solids not fat, and the control 

 sample contains 4.5 per cent of fat and 8.85 

 per cent of solids not fat, how was the milk 

 adulterated and what was the per cent of 

 adulteration? 

 By comparing the solids not fat in the two 

 samples it will be seen that the milk has been 

 watered, because the solids not fat are reduced. 

 Calculate the per cent of added water by determin- 

 ing the quantity of solids displaced by it. 

 8.85— 8.2=.65. 



.65 -f-8.85=.0734X 100=7.34 per cent of added 

 water. 



Next determine how much the fat is reduced. 

 4.5—2.8=1.7. 



1. 7-^-4.5=. 3777X100=37.7 per cent of fat miss- 

 ing. 



Since we know that the solids not fat have been 



