184 SOILS AND FERTILIZERS 



tion of hydrochloric acid from a burette until the solu- 

 tion is neutral. If a standard solution of acid cannot 

 be procured, one containing i5cc. concentrated hydro- 

 chloric acid per liter of distilled water may be used for 

 comparative purposes. Leached ashes require less than 

 2 cc. of acid to neutralize the alkaline matter in i gram 

 while unleached ashes require from 10 to 18 cc. In pur- 

 chasing wood ashes, if a chemical analysis cannot be 

 secured, the alkalinity of the ash should be determined. 



242. Coal and other Ashes. Since the amount of 

 phosphoric acid and potash in coal ashes is very small, 

 they have but little fertilizer value. Soft-coal ashes 

 contain more potash than those from hard coal, but it 

 is held in such firm combination as to be of but 

 little value. 



The ashes from sawmills where soft wood is burned 

 and the ashes are unprotected, are nearly worthless. 

 When peat-bogs are burned over, large amounts of ashes 

 are produced. If the bogs are covered with timber, 

 the ashes are sometimes of sufficient value to warrant 

 their transportation and use. 



Phosphoric 



Potash acid. 



Per cent. Per cent. 



Hard coal ashes o.io o. 10 



Soft coal ashes 0.40 0.40 



Sawmill ashes u 1.20 i.oo 



Peat-bog ashes 1 * 1.15 0.54 



Peat-bog ashes (timbered) 14 3.68 2.56 



Tobacco stem ash 4.00 7.00 



Cottonseed hulls, ash 20.00 7.00 



243. Commercial Value of Potash. The market 

 value of potash is governed by the selling price of 



