WOOL ASHES 183 



239. Action of Ashes on Soils. Ashes act upon 

 soils both chemically and physically. They are usu- 

 ally regarded as a potash fertilizer only, but they also 

 contain lime and phosphoric acid, and may be very 

 beneficial in supplying these elements. The potash 

 is present mainly as potassium carbonate. Ashes are 

 valuable, too, because they add alkaline matter to the 

 soil, which corrects acidity and aids nitrification. A 

 dressing of ashes improves the mechanical condition 

 of many soils by binding the soil particles. This 

 property is well illustrated in the so-called "Gumbo" 

 soils, which contain so much alkaline matter that the 

 soil has a soapy taste and appearance, and when plowed 

 the particles fail to separate. 



240. Leached Ashes. When ashes are leached the 

 soluble salts are extracted ; the insoluble matter 

 which is left is composed mainly of calcium carbonate 

 and silica. 66 



Unleached ashes. Leached ashes. 



Per cent. Per cent. 



Water 12.0 30.0 



Silica, etc 13.0 13.0 



Potassium carbonate 5.5 i.i 



Calcium 61.0 51.0 



Phosphoric acid 1.9 1.4 



241. Alkalinity of Leached and Unleached Ashes. 



A good way to detect leached ashes is to deter- 

 mine the alkalinity in the following way : Weigh 

 out 2 grams of ashes into a beaker, add 100 cc. dis- 

 tilled 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 solu- 



