39 



The adulterations are as follows : 



1. Addition of water. 



2. Partial removal of cream, skimming. 



3. Skimming and watering. 



4. Mixing of partially skimmed (evening or morning) milk 

 with whole milk. 



5. Foreign substances to disguise the altered or unnatural ap- 

 pearance of milk. 



Most cases of adulteration are to be classed under 1 to 4, those 

 under 5 being used to reestablish a normal appearance of adulter- 

 ated milk. 



The following substances are known to be used for this purpose : 

 sugar, gum arabic, starch, dextrine, egg albumen, yolk of eggs, 

 earthy substances, alkalies and dyes, to blend the blue color of skim 

 milk. 



Most of these adulterants exist more in books than that they 

 are actually met with, for substances which can easily be found 

 by simple chemical reactions, or even by mechanical means, or 

 which may easily be discovered by taste or smell, are not those 

 which fraudulent dealers would be apt to choose. 



Those who adulterate know well that chemists possess all the 

 means to detect such coarse adulteration ; they therefore confine 

 their operations mainly to watering, and the mixing of skim milk 

 with whole milk, in various proportions. 



Watery milk: Watery milk of a bluish-white color, poor in 

 fats and solids, is generally derived from cows under inferior treat- 

 ment, or when fed with extraordinarily poor and watery food. A 

 measure for the value of such milk is its specific gravity. This is, 

 however, governed by the quantities in which the various constit- 

 uents are present, for while salts, albuminates and milk sugar ^nd 

 to increase the specific gravity, the fat tends to diminish it. 



If whole milk be mixed with water, the specific gravity will be 

 reduced, and analysis will show an excess of water and, correspond- 

 ingly, a diminished quantity of solids. 



If milk be more or less skimmed, the specific gravity is in- 

 creased. By means of the lactometer or lactodensimeter, dealers 

 are enabled to dilute it with water to such an extent, that the spe- 

 cific gravity reached is within the limits of the law. A determina- 



