22O 



SOILS AND FERTILIZERS 



256. Alkalinity of Leached and Unleached Ashes. - 

 A good way to detect leached ashes is to determine the 

 alkalinity in the following way : weigh out 2 grams of 

 ashes into a beaker, add 100 cc. distilled water, and 

 heat on a sand bath nearly to boiling, cool and filter. 

 To 50 cc. of the filtrate add about 3 drops of cochineal 

 indicator, and then a standard solution of hydrochloric 

 acid from a burette until the solution is neutral. If a 

 standard solution of acid cannot be procured, one con- 

 taining 15 cc. concentrated hydrochloric acid per liter 

 of distilled water may be used for comparative pur- 

 poses. Leached ashes require less than 2 cc. of acid 

 to neutralize the alkaline matter in I gram, while un- 

 leached ashes require from 10 to 18 cc. In purchasing 

 wood ashes, if a chemical analysis cannot be secured, 

 the alkalinity of the ash should be determined. 



257. Coal and Other Ashes. Since the amount of 

 phosphoric acid and potash in coal ashes is very small, 

 they have little fertilizer value. Soft coal ashes contain 



