78 DAIRY CHEMISTRY 



and absorbents should be used. In localities where 

 straw cannot be procured, sawdust, shavings, peat, 

 and other materials are employed. In addition, a 

 small amount of land plaster, or gypsum, will be 

 found valuable for the purpose of deodorizing the 

 stable. Gypsum is used at the rate of about half a 

 pound per day for each animal and is sprinkled in 

 the stalls and trenches. Lime in any other form 

 than the sulphate is not suitable for use in the stable. 

 Instead of absorbing the odors, quicklime and slaked 

 lime decompose the refuse materials, causing more 

 odors to be produced. Lime sulphate, or land plaster, 

 can usually be procured at about 15.00 per ton, and 

 is a valuable fertilizer; when added to the manure 

 it increases its value by preventing unnecessary fer- 

 mentation and loss of ammonia. Some deodorizing 

 materials and so-called disinfectants simply mask the 

 odors of the stable without disinfecting them. Not 

 only the stables, but often filthy yards and fields, are 

 direct causes of pollution of milk, and some of the 

 diseases to which milk is subject are due to contami- 

 nation from the soil. Where a large amount of 

 manure is banked against the stable, the air which 

 diffuses through the walls is contaminated. Un- 

 drained pasture lands are often a cause of trouble, 

 and occasionally the output of a creamery or cheese 

 factory is lessened in value because of such contami- 

 nation. Numerous cases of this character are on 

 record. Mr. Willard, a pioneer American cheese- 

 factory man, found that the production of a poor 



