394 MILK AND ITS PRODUCTS 



in school, more farmers may purchase them. The school in this way 

 serves the community. 



2. Those who are not producers, but only consumers of milk, will 

 be interested in tests for milk preservatives. If a trace of formalin (a 

 very common preservative) has been added to milk to keep it from 

 becoming sour, pour a little of the rnilk in a cup together with a few 

 drops of sulphuric acid, having in it a little iron chloride (a teaspoon- 

 f ul of the iron solution to a pint of acid) ; stir the solution. A 

 purple color shows the presence of formalin. 



REFERENCES 



Modern Methods of Testing Milk and Milk Products. Van Slyke. 

 Principles and Practice of Butter Making, McKay and Larson. 

 First Lessons in Dairying. Van Norman. 

 Milk and Its Products. King. 

 A. B.C. in Cheese Making. 

 Farmers' Bulletins. Washington, D.C. 

 42. Facts about Milk. 

 63. Care of Milk on the Farm. 

 74. Milk as Food. 

 166. Cheese Making on the Farm. 

 241. Butter Making on the Farm. 

 413. The Care of Milk and its Use in the Home. 

 490. Bacteria in Milk. 



