CHAPTEE IV 



THE APPLICATION OF ANALYSIS TO THE 

 SOLUTION OF PROBLEMS 



The Detection of Adulteration. The principal forms 

 of adulteration of milk are the addition of water and 

 the removal of cream. 



The detection of water is based on the reasoning that 

 while the water natural to milk contains solids not fat, 

 added water is free from these. The amount of solids 

 not fat is nearly though not quite constant, and rarely 

 falls below 8.5 per cent, or rises much above 9.2 per 

 cent. ; numerous cases, however, are on record of solids 

 not fat below 8.5. 



The removal of cream is detected by a deficiency in 

 the fat ; this varies much more than the solids not fat, 

 but comparatively rarely falls below 3.0 per cent. 



The probability of samples falling below 8.5 per 

 cent, of solids not fat, and 3.0 per cent, of fat is indi- 

 cated by the following Table, which gives the number 

 of samples per 100,000 which may be expected at each 

 percentage named ; it is assumed that each sample 

 represents a churn of milk, i.e. that the milk is the 

 mixed product of several cows. 



TABLE VI 



