THE ADULTERATION OF DAIRY PRODUCTS 117 



ether. The fat is then raised into a graduated tube, 

 where it is measured. The Cochrane fat bottles are 

 made with two tubes, one for measuring the fat and 

 the other for adding the reagents. 



In Failyer and Willard's method an acid first is 

 added to the milk, and then gasoline to collect the 

 fat. The gasoline is removed by a current of air, 

 and the fat is collected in the graduated neck of 

 the test bottle and measured. 



The Lactoscope and Feser's Pioscope were quite 

 extensively used at one time. They are optical 

 methods and depend upon the opacity of the milk 

 serum. Both of these methods are totally unreli- 

 able, the results being very inaccurate. 



Most of these short methods are not sufficiently 

 accurate for scientific work, or as final evidence in 

 court in case of adulteration. 



108. Dairy Laws. — Some states and countries 

 have passed laws prohibiting the sale of adulterated 

 dairy products. Congress has also passed a national 

 law prohibiting the coloring of oleomargarine to 

 resemble butter. The injury which results from 

 the sale of oleomargarine and filled cheese is due 

 more to their being dishonest competitors than to 

 their unwholesomeness. They are fi-equently sold 

 for butter and cheese, and since they are made 

 to resemble them, it is often difficult for the inex- 

 perienced person to detect the adulterated article. 

 As to digestibility and food value, there is not a 

 great difference between butter and oleomargarine. 



