l^i>'vlfl. .'//^A^ I ^ 



122 



ACTION OF SALTS. 



tables, because he always employs a portion of lime to make 

 his lye caustic. This is a variable portion ; whatever it is, 

 it adds so much to the value of the leached ashes. Besides, 

 the soap-maker always leaves a portion of alkali, which is 

 combined with the silex. Exposure to air decomposes this, 

 and then the alkali can be extracted by water. This is one 

 great source of the active power of leached ashes. 



164. A bushel of good ashes contains about 4^ lbs. of real 

 potash. In leaching ashes, generally about one pound of 

 lime is added to each bushel of ashes, and as it loses no bulk 

 during the operation, a cord of leached ashes contains about 

 the following proportions, allowing the usual proportion of 

 potash to be leached out, or 4 lbs. per bushel : — 



147 lbs. 



Combining the phosphoric acid with lime to form bone dust, 

 and converting the remainder of the lime into carbonate, a 

 cord of leached ashes contains : 



319 lbs. 



4577 « 



