MANTTKES. 137 



from wliicli to obtain this alkali. The ashes of all 

 kinds of wood contain potash (more or less, according 

 to the kind — see analyses. Section Y.) If the ashes 

 are leached^ mnch of the potash is removed; and 

 hence, for the pnrpose of supplying it, they are less 

 valuable than unleaclied ashes. The latter may be 

 made into compost with muck, as directed in a pre- 

 vious chapter, or applied directly to the soil. In 

 either case the potash is available directly to the 

 plant, or is capable of uniting with the silica in the 

 soil to form silicate of potash. Leached ashes con- 

 tain too little potash to be valuable in the compost, 

 but, from their imperfect leaching, they do contain 

 enough to make them valuable as manure. Neithei 

 potash nor any other alkali should ever be applied to 

 animal manures unless in compost with an absorbent, 

 as they cause the ammonia to be thrown off and lost. 



Potash sparlings^ or the refuse of potash ware- 

 houses, is an excellent manure for lands deficient in 

 this constituent. 



Feldspar, kaolin, and other minerals containing 

 potash, are, in some localities, to be obtained in suf- 

 ficient quantities to be used for manurial purposes. 



Within a comparatively few years, a new fer- 

 tilizer — of great value to all regions within carrying 

 distance of its place of deposit — has been brought 

 to the notice of farmers near the seaboard. This is 

 the Green Sand Marl of New Jersey, which under- 

 lies a wide belt extending from the Atlantic Ocean to 

 the Delaware River, having an area of about 900 

 square miles. It is very largely used in South Jersey, 



