Detection of Adui,terants and Preservatives 295 



Chapter XXXIII. 



DETECTION OF ADULTERANTS AND PRESERVATIVES 



IN MILK 



Addition of Water and Skim Milk and the Removal of Cream 



Frequency of Adulteration. — Experience has shown that 

 where milk is received from a large number of patrons, as is the 

 case in most milk condensing factories, some of the milk may be and 

 frequently is being tampered with before it reaches the factory. 

 In the case of condenseries buying and paying for the milk on the 

 butter fat basis, neither the watering nor the skimming of the milk 

 results in any material direct loss to the factory. Excessive skim- 

 ming, however, does reduce the yield of the finished product some- 

 what, inasmuch as a small amount of solids is removed with the 

 cream. Excessive watering necessitates the expenditure of slightly 

 more fuel to remove the extraneous water in the process of evap- 

 oration. 



Where the condensery buys and pays for its milk by the hun- 

 dred weight, however, it is obviously essential that such adultera- 

 tions be guarded against by eternal vigilance. 



Taking and Preserving of the SampIvE. — In order to min- 

 imize the. work of testing without interfering with the effectiveness 

 of the control, it is advisable to take composite samples. Use pint 

 jars with tight lids ; label the jars with the number of the respective 

 patron and place them in numerical order on conveniently located 

 shelves on the receiving platform. In the case of the route system 

 of receiving milk, the samples of milk from each route should be 

 stored together. Use a dipper holding one ounce of milk ; by pour- 

 ing a dipperful of milk of each patron each day into the respective 

 jars, enough milk is collected in each jar at the end of two weeks 

 to test with the lactometer and the Babcock tester every two weeks. 



In order to preserve the samples in proper condition drop a 

 large corrosive sublimate tablet into each empty jar and after each 

 addition of milk, mix the corrosive sublimate with the milk by 

 giving the jar a rotary motion. Add one dipperful of each patron's 

 milk daily into the jars. ~ 



Testing the Composite Samples. — At the end of every two 

 weeks test the samples with the Quevenne lactometer and the Bab- 



